Nexa Resources S.A.
For the period ended Dec 31, 2024. Filed Mar 27, 2025.
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The yearly report of a company based outside the US. It covers much of what a 10-K does, and may follow accounting rules other than US ones.
FY2024 · Filed Mar 27, 2025
Contents
Mining operations
Map 1. Mines, Projects and Prospects in Peru
*Source:*Nexa Resources.
Mining Operations
Map 2. Mines, Projects and Prospects in Brazil
*Source:*Nexa Resources.
The following table summarizes our concentrate production, metal contained in concentrate production in each metal and zinc equivalent production in each of our operating mines.
To calculate the zinc equivalent production for the years ended December 31, 2024, 2023, and 2022, we convert the relevant metal contained in concentrate production used in the zinc equivalent grade based on the average benchmark prices for 2024, namely, US$2,779.0 per tonne (US$1.26 per pound) for zinc, US$9,146.8 per tonne (US$4.15 per pound) for copper, US$2,072.7 per tonne (US$0.94 per pound) for lead, US$28.3 per ounce for silver and US$2,386.2 per ounce for gold.
Mining Operations
| For the Year Ended December 31, | |||
|---|---|---|---|
| 2024 | 2023 | 2022 | |
| Treated Ore (in tonnes) | 13,420,966 | 13,846,530 | 12,343,018 |
| Mining Production—Metal Contained in Concentrate | |||
| Zinc (in tonnes) | 326,995 | 333,154 | 296,403 |
| Copper (in tonnes) | 35,698 | 33,385 | 33,219 |
| Lead (in tonnes) | 69,303 | 65,194 | 57,448 |
| Silver (in oz) | 11,694,073 | 10,300,672 | 9,974,462 |
| Gold (in oz) | 36,027 | 27,627 | 27,216 |
| Mining Production—Zinc Equivalent Production | |||
| Cerro Lindo (in tonnes of zinc equivalent) | 242,567 | 220,984 | 249,446 |
| Vazante (in tonnes of zinc equivalent) | 146,229 | 152,598 | 137,210 |
| El Porvenir (in tonnes of zinc equivalent) | 125,654 | 126,500 | 120,319 |
| Atacocha (in tonnes of zinc equivalent) | 39,738 | 37,212 | 41,330 |
| Aripuanã (in tonnes of zinc equivalent) | 82,775 | 53,502 | 1,755 |
| Morro Agudo(1) (in tonnes of zinc equivalent) | 9,946 | 36,191 | 30,474 |
| Total | 646,908 | 626,987 | 580,535 |
(1) Considers only the four months of operations from January to April 2024. On April 30, 2024, we sold the Morro Agudo Complex.
The following table summarizes the average ore grade for the periods indicated.
| For the Year Ended December 31, | |||
|---|---|---|---|
| 2024 | 2023 | 2022 | |
| Average Ore Grade | |||
| Zinc (%) | 2.90 | 2.90 | 2.78 |
| Copper (%) | 0.35 | 0.34 | 0.34 |
| Lead (%) | 0.67 | 0.66 | 0.62 |
| Silver (in ounces per tonne) | 1.16 | 1.00 | 1.07 |
| Gold (in ounces per tonne) | 0.006 | 0.005 | 0.005 |
Each of these mining properties consists of one mine, one treatment plant and related infrastructure. We summarize below information as of December 31, 2024, for each of our five mines. For an overview of our reserves and resources, see “Mineral Reserves and Resources—Disclosure of Mineral Reserves and Resources”, “Mineral Reserves and Resources—Mineral Reserves” and “Mineral Reserves and Resources—Mineral Resources.”
We have determined that our material properties are Cerro Lindo, Vazante, Cerro Pasco Complex and Aripuanã. As there has been no material changes in the reported reserves or resources for these mining properties since the last Technical Report Summary filed, we are not including new Technical Report Summaries in connection with this filing. Below is the individual property disclosure for each of these properties.
Cerro Lindo
The Cerro Lindo mine is an underground, polymetallic mine located in the Chavín District, Chincha Province, Peru, approximately 268 km southeast of Lima and 60 km from the coast. Access from Lima is available via the paved Pan American Highway south to Chincha, and then via an unpaved road up the Topará River valley to the mine site. Internal roadways connect the various mine site components. The approximate coordinates of the mine are 392,780m East and 8,554,165m North, using the Universal Transverse Mercator WGS84 datum and the mine site is located at an average elevation of 2,000 meters above sea level.
Mining Operations
History
Several companies have held interests in the Cerro Lindo mine area, including BTX, Phelps Dodge, and Nexa Peru. Exploration work completed to date includes geological mapping, rock chip and soil sampling, trenching, ground geophysical surveys, and exploration, definition and underground operational core drilling. Feasibility studies were completed in 2002 and 2005, with mine construction commencing in 2006. Formal production started in 2007, and the mine has been operational since that date.
All mineral concessions are held in the name of Nexa Peru. The tenure consists of 68 mining concessions totaling approximately 43,927.8 hectares and one beneficiation concession, covering an area of 518.8 hectares.
Nexa Peru currently holds surface rights or easements for the following infrastructure at Cerro Lindo: mine site, access roads, power transmission line and water pipeline for the mine, old and new power transmission lines to Cerro Lindo, desalination plant, water process plant, and the water pipeline from the desalination plant to the mine site. There is sufficient suitable land available within the mineral tenure held by Nexa Peru for tailings disposal, mine waste disposal and installations such as the process plant and related mine infrastructure.
Cerro Lindo is currently subject to payment of royalties. The tax stability agreement expired on December 31, 2021, and the historical applicability thereof is subject to certain disputes with tax authorities. For more information, see “Additional Information—Legal Proceedings—Other legal proceedings.” As of January 2022, Nexa Peru is required to pay royalties and special mining tax to the Peruvian government. For more information, see “Information on the Company—Regulatory matters—Peruvian regulatory framework.” As of December 31, 2024, Nexa Peru held a seawater extraction license, granted under Administrative Resolution No. 0033-2012-ANA-ALA MOC, for a total volume of 3,153,600 m 3 per year (8,640 m 3 per day).
Cerro Lindo holds a number of permits in support of the current operations. The permits are Resolutions issued by the Peruvian authorities upon approval of mining environmental impact assessments filed by the mining companies. Nexa Peru maintains an up-to-date record of the legal permits obtained to date.
Cerro Lindo is classified as a volcanogenic massive sulfide (“VMS”) deposit. The Cerro Lindo deposit is 1,500 meters long, 1,000 meters wide, and has a current vertical development of 470 meters below the surface. Mineralization consists of at least 10 discrete mineralized zones. The Cerro Lindo deposit comprises lens-shaped massive bodies, composed of pyrite (50.0% to 90.0%), yellow sphalerite, brown sphalerite, chalcopyrite, and minor galena. Significant barite is present mainly in the upper portions of the deposit. A secondary-enrichment zone, composed of chalcocite and covellite, has formed near the surface where massive sulfides have oxidized. Silver-rich powdery barite remains at the surface as a relic of sulfide oxidation and leaching.
In 2024, mineral exploration in Cerro Lindo focused on extending known orebodies, particularly OB-8B and OB-8C, located southeast of the mine, and investigating potential new mineralized zones. Exploration efforts also targeted the Patahuasi Millay geophysical anomaly, which was the main focus of exploratory drilling in 2024 and resulted in its transition to an early-stage greenfield target. Drill holes at the Pucasalla target and its extensions indicated the presence of sulfide zones but without significant results. Drilling activities also continued at the Puca Punta target. Despite some delays caused by weather and operational challenges, significant progress was made in advancing the exploration program.
During 2024, we completed approximately 25.4 km of diamond drilling in 25 drill holes with 4 drill holes currently in progress that are expected to be concluded in 2025, divided between surface and underground exploration drillings. By the end of 2024, we had achieved key milestones, including significant advancements in extending known orebodies and evolving the exploratory drilling program.
Mining Operations
During 2025, we expect to complete a total of 7.6 km of exploratory drilling. Our goals are to continue extending known orebodies, including OB-8C, and to construct new access and platforms to support the exploratory drilling program.
In 2024, we spent US$9.2 million in exploration expenses for Cerro Lindo, primarily associated with diamond drilling, geochemistry analysis and geological research works. We have budgeted US$3.5 million for 2025 to continue our exploration program, including data interpretations, geochemistry, geophysical and exploratory drilling campaign, including near mine drilling.
The Cerro Lindo mine is substantially mechanized, using rubber-tired equipment for all development and production operations. There is no shaft; all access is through 15 portals servicing adits, drifts and declines. Ore is extracted from nine separate ore bodies and delivered to the process plant via a series of conveyors. All ore is commingled during transport to the concentrator stockpile; ore from different ore bodies is not segregated.
We have completed construction of all key infrastructure required for mining and processing operations, including the underground mine, access roads, power lines, water pipelines, the desalination plant, offices and warehouses, accommodations, the process plant/concentrator, conveyor systems, waste rock facilities, temporary ore stockpiles, the paste-fill plant and the dry-stack tailings storage facilities. A new freshwater pipeline from the desalination plant on the coast to the mine was completed in 2020 and is operational. The national grid supplies electrical power for the mine site.
In 2024, we spent US$47.1 million on sustaining capital expenditures for Cerro Lindo, primarily associated with mine development and equipment replacement.
In 2024, exploration drilling activities faced delays due to heavy rainfall at the mine site and operational challenges related to exploratory drilling in long hole drilling; however, these disruptions did not significantly impact the overall progress of the exploration program.
In 2024, Nexa began using Digital Twin technology and predictive maintenance at Cerro Lindo. The use of this technology has delivered significant operational improvements. This pilot project aims to use AI models for testing, analysis, and simulations to improve operational performance. As a result, the project may achieve significant operational improvements, including an increase in milling capacity, a reduction in water consumption, and a decrease in crusher downtime. For risks related to the use of AI, please see “Risk Factors—Business risks—Our information and operational technology systems may be adversely affected by disruptions, damage, failure and risks associated with implementation and integration, including new technologies”.
The Cerro Lindo mine is in the production stage and has a treatment plant capacity of 21,000 tonnes of ore per day. The Cerro Lindo unit has an authorized capacity of 20,000 tonnes of ore per day, but Peruvian law allows units to operate at a capacity 5.0% higher than their authorized capacity. The table below summarizes the Cerro Lindo mine’s concentrate production, metal contained in concentrates produced and average grades for the periods indicated. Production in 2024 was higher than 2023 primarily as a result of enhanced operational performance, access to areas with higher grades, especially in the first half of 2024, improved plant efficiency, and increased volume of treated ore.
| For the Year Ended December 31, | |||
|---|---|---|---|
| 2024 | 2023 | 2022 | |
| Treatment ore (in tonnes) | 6,080,038 | 5,991,156 | 6,236,058 |
| Average ore grade | |||
| Zinc (%) | 1.62 | 1.51 | 1.55 |
| Copper (%) | 0.58 | 0.57 | 0.61 |
| Lead (%) | 0.31 | 0.31 | 0.33 |
| Silver (ounces per tonne) | 0.93 | 0.80 | 0.89 |
| Gold (ounces per tonne) | 0.003 | 0.002 | 0.002 |
Mining Operations
| Metal contained in concentrates production | |||
|---|---|---|---|
| Zinc (in tonnes) | 86,207 | 78,209 | 84,392 |
| Copper (in tonnes) | 29,888 | 28,588 | 32,758 |
| Lead (in tonnes) | 13,891 | 13,042 | 15,641 |
| Silver (in oz) | 4,268,043 | 3,540,975 | 4,129,736 |
| Gold (in oz) | 4,904 | 3,418 | 4,146 |
| Cash Cost, net of by-product credits (in US$/t) | (1,010.6) | (138.6) | (561.4) |
| Cash Cost, net of by-product credits (in US$/lb) | (0.46) | (0.06) | (0.25) |
| Non-Expansion Capital Expenditures (in millions of US$) | 49.0 | 43.3 | 42.5 |
The Cerro Lindo Mineral Reserves estimates are based on the definitions for Mineral Reserves in SK-1300 and the tables below are based on costs and modifying factors from the Cerro Lindo mine.
Cerro Lindo – Year End Mineral Reserves as of December 31, 2024 (on an 83.55% Nexa attributable ownership basis)(1)
| Grade · Contained Metal | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Class | Tonnage (2) | Zinc | Copper | Silver | Lead | Gold | Zinc | Copper | Silver | Lead | Gold |
| (Mt) | (%) | (%) | (g/t) | (%) | (g/t) | (kt) | (kt) | (koz) | (kt) | (koz) | |
| Proven | 20.79 | 1.56 | 0.57 | 19.7 | 0.19 | - | 323.6 | 118.1 | 13,183 | 38.9 | - |
| Probable | 11.85 | 1.07 | 0.43 | 24.2 | 0.22 | - | 127.2 | 50.5 | 9,238 | 26.4 | - |
| Total | 32.64 | 1.38 | 0.52 | 21.4 | 0.20 | - | 450.8 | 168.6 | 22,421 | 65.2 | - |
| 1. | Subpart 1300 of Regulation S-K definitions were followed for Mineral Reserves, which also are consistent with the CIM (2014) definitions. |
| 2. | Mineral Reserves data presented in this table are reported on 83.55% Nexa attributable ownership. |
| 3. | The Qualified Person for the Mineral Reserves estimate is Cesar Moreno, B.Eng., MAusIMM, a Nexa employee. |
| 4. | Numbers may not add due to rounding. |
| 5. | The point of reference for Mineral Reserves in this table is mill feed materials. |
Cerro Lindo – Year End Mineral Reserves as of December 31, 2024 (on a 100% ownership basis)(1)
| Grade · Contained Metal | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Class | Tonnage (2) | Zinc | Copper | Silver | Lead | Gold | Zinc | Copper | Silver | Lead | Gold |
| (Mt) | (%) | (%) | (g/t) | (%) | (g/t) | (kt) | (kt) | (koz) | (kt) | (koz) | |
| Proven | 24.88 | 1.56 | 0.57 | 19.7 | 0.19 | - | 387.3 | 141.3 | 15,779 | 46.5 | - |
| Probable | 14.19 | 1.07 | 0.43 | 24.2 | 0.22 | - | 152.2 | 60.4 | 11,057 | 31.5 | - |
| Total | 39.07 | 1.38 | 0.52 | 21.4 | 0.20 | - | 539.5 | 201.8 | 26,836 | 78.1 | - |
| 1. | Subpart 1300 of Regulation S-K definitions were followed for Mineral Reserves, which also are consistent with the CIM (2014) definitions. |
| 2. | Mineral Reserves data presented in this table represents 100% of the Mineral Reserves estimates for the property. Nexa owns 83.55% |
| 3. | The Qualified Person for the Mineral Reserves estimate is Cesar Moreno, B.Eng., MAusIMM, a Nexa employee. |
| 4. | Numbers may not add due to rounding. |
| 5. | The point of reference for Mineral Reserves in this table is mill feed materials. |
The Cerro Lindo Mineral Reserves are estimated at an NSR cut-off value of US$44.94/t processed. A number of incremental material (with values between US$33.33/t and US$44.94/t) was included. A minimum mining width of 7.0 m was used, inclusive of extraction factors and dilution are applied based on stope type and location. The net smelter return (“NSR”) cut-off value is determined using the mineral reserve metal prices, metal recoveries, concentrate transport, treatment and refining costs, as well as mine operating costs. Metal prices used for Mineral Reserves are based on consensus, long-term forecasts from banks, financial institutions and other sources. Mineral Reserves estimates are based on average long-term metal prices of zinc: US$2,864.90/t (US$1.30/lb); copper: US$9,095.61/t (US$4.13/lb); lead: US$2,097.45/t (US$0.95/lb); and silver: US$24.83/oz. Metallurgical recoveries are accounted for in NSR calculations based on historical processing data and are variable as a function of head grade. Recoveries at life of mine (“LOM”) average head grades are 87.86% for Zn, 84.47% for Cu, 65.65% for Pb, and 68.78% for Ag. The current LOM plan continues to 2031.
Mining Operations
Cerro Lindo – Net Difference in Mineral Reserves between December 31, 2024, versus December 31, 2023 (on an 83.55% Nexa attributable ownership basis)
| Contained Metal | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Class · Tonnage · Zinc · Copper · Silver · Lead · Gold | ||||||||||||
| (Mt)% · (kt)% · (kt)% · (koz)% · (kt)% · (koz)% | ||||||||||||
| Proven | (1.04) | (4.8) | (43.5) | (11.8) | (14.5) | (10.9) | (1,680) | (11.3) | (5.2) | (11.8) | - | - |
| Probable | (0.67) | (5.3) | (17.2) | (11.9) | (6.4) | (11.2) | (915) | (9.10 | (3.6) | (12.0) | - | - |
| Total | (1.71) | (5.0) | (60.6) | (11.9) | (20.9) | (11.0) | (2.595) | (10.4) | (8.8) | (11.9) | - | - |
Cerro Lindo – Net Difference in Mineral Reserves between December 31, 2024, versus December 31, 2023 (on a 100% ownership basis)
| Contained Metal | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Class · Tonnage · Zinc · Copper · Silver · Lead · Gold | ||||||||||||
| (Mt)% · (kt)% · (kt)% · (koz)% · (kt)% · (koz)% | ||||||||||||
| Proven | (1.27) | (4.9) | (52.4) | (11.9) | (17.5) | (11.0) | (2,024) | (11.4) | (6.3) | (11.9) | - | - |
| Probable | (0.81) | (5.4) | (20.7) | (12.0) | (7.7) | (11.2) | (1,105) | (9.1) | (4.3) | (12.0) | - | - |
| Total | (2.08) | (5.1) | (73.1) | (11.9) | (25.1) | (11.1) | (3,130) | (10.4) | (10.6) | (12.0) | - | - |
In comparison to 2023, Cerro Lindo’s Mineral Reserves decreased by 5.1% in mass to total 39.1 Mt from 41.2Mt and decreased by 11.9% in zinc content (kt), mainly due to an 18.0% decrease in Mineral Reserves average head grade, as a result of the depletion in higher grade areas, lower grades in areas upgraded from infill drilling, as well as improved NSR (“Net Smelter Return”) as a result of higher metal prices. Mineral Reserve depletion during 2024 represented 6.1Mt containing 99.8kt of zinc.
Cerro Lindo – Year End Mineral Resources as of December 31, 2024 (on an 83.55% Nexa attributable ownership basis)(1)
| Grade · Contained Metal | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Class | Tonnage (2) | Zinc | Copper | Silver | Lead | Gold | Zinc | Copper | Silver | Lead | Gold |
| (Mt) | (%) | (%) | (g/t) | (%) | (g/t) | (kt) | (kt) | (koz) | (kt) | (koz) | |
| Measured | 3.01 | 2.04 | 0.72 | 23.0 | 0.23 | - | 61.3 | 21.8 | 2,225 | 7.0 | - |
| Indicated | 2.41 | 0.99 | 0.50 | 22.3 | 0.19 | - | 23.7 | 12.1 | 1,725 | 4.6 | - |
| Total | 5.42 | 1.57 | 0.63 | 22.7 | 0.22 | - | 85.0 | 33.9 | 3,950 | 11.7 | - |
| Inferred | 8.39 | 1.53 | 0.27 | 25.5 | 0.39 | - | 128.1 | 22.5 | 6,862 | 32.9 | - |
| 1. | Subpart 1300 of Regulation S-K definitions were followed for Mineral Resources, which also are consistent with the CIM (2014) definitions. |
| 2. | Mineral Resources Tonnes and Contained Metal presented in this table are reported on 83.55% Nexa attributable ownership. |
| 3. | Mineral Resources are reported exclusive of those Mineral Resources that were converted to Mineral Reserves, and Mineral Resources are not Mineral Reserves and do not have demonstrated economic viability. |
| 4. | The Qualified Person for the Mineral Resources estimate is Jerry Huaman Abalos, B.Geo., MAusIMM CP(Geo), a Nexa employee. |
| 5. | Numbers may not add due to rounding. |
| 6. | The point of reference for Mineral Resources in this table is mill feed materials. |
Mining Operations
Cerro Lindo – Year End Mineral Resources as of December 31, 2024 (on a 100% ownership basis)(1)
| Grade · Contained Metal | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Class | Tonnage (2) | Zinc | Copper | Silver | Lead | Gold | Zinc | Copper | Silver | Lead | Gold |
| (Mt) | (%) | (%) | (g/t) | (%) | (g/t) | (kt) | (kt) | (koz) | (kt) | (koz) | |
| Measured | 3.60 | 2.04 | 0.72 | 23.0 | 0.23 | - | 73.3 | 26.1 | 2,663 | 8.4 | - |
| Indicated | 2.88 | 0.99 | 0.50 | 22.3 | 0.19 | - | 28.4 | 14.5 | 2,065 | 5.6 | - |
| Total | 6.48 | 1.57 | 0.63 | 22.7 | 0.22 | - | 101.7 | 40.6 | 4,727 | 14.0 | - |
| Inferred | 10.04 | 1.53 | 0.27 | 25.5 | 0.39 | - | 153.3 | 26.9 | 8,213 | 39.3 | - |
| 1. | Subpart 1300 of Regulation S-K definitions were followed for Mineral Resources, which also are consistent with the CIM (2014) definitions. |
| 2. | Mineral Resources data presented in this table represents 100% of the Mineral Resources estimates for the property. Nexa owns 83.55%. |
| 3. | Mineral Resources are reported exclusive of those Mineral Resources that were converted to Mineral Reserves, and Mineral Resources are not Mineral Reserves and do not have demonstrated economic viability. |
| 4. | The Qualified Person for the Mineral Resources estimate is Jerry Huaman Abalos, B.Geo., MAusIMM CP(Geo), a Nexa employee. |
| 5. | Numbers may not add due to rounding. |
| 6. | The point of reference for Mineral Resources in this table is mill feed materials. |
The Cerro Lindo Mineral Resources estimates in the table above were completed using Datamine Studio RM (“Datamine”) and Seequent’s Leapfrog Geo (“Leapfrog”) software. Wireframes for geology and mineralization were constructed in Leapfrog based on geology sections, assay results, lithological information, underground mapping and structural data. Assays were capped to various levels based on exploratory data analysis and then composited to 2.5 m lengths. Wireframes were filled with blocks sub-celled at wireframe boundaries. Blocks were interpolated with grade using the Ordinary Krig (“OK”) and Inverse Distance to the cube (“ID 3”) interpolation algorithms. Block estimates were validated using industry standard validation techniques. Classification of blocks used distance-based and other criteria. Mineral Resources estimates were reported using all the material within resource shapes generated in Deswik Stope Optimizer (“DSO”) software. The estimate satisfied the minimum mining width of 4.0 m for resource shapes and used NSR cut-off value of US$44.94/t. Mineral Resources estimates are based on average long-term metal prices of zinc: US$3,294.64/t (US$1.49/lb); copper: US$10,459.95/t (US$4.74/lb); lead: US$2,412.07/t (US$1.09/lb); and silver: US$28.55/oz. Metallurgical recoveries are accounted for in NSR calculations based on historical processing data and are variable as a function of head grade. Recoveries at LOM average head grades are 87.86% for Zn, 84.47% for Cu, 65.65% for Pb, and 68.78% for Ag.
Cerro Lindo – Net Difference in Mineral Resources between December 31, 2024, versus December 31, 2023 (on an 83.55% Nexa attributable ownership basis)
| Contained Metal | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Class · Tonnage · Zinc · Copper · Silver · Lead · Gold | ||||||||||||
| (Mt)% · (kt)% · (kt)% · (koz)% · (kt)% · (koz)% | ||||||||||||
| Measured | (0.66) | (18.0) | (9.6) | (13.5) | (2.1) | (8.7) | (504) | (18.5) | (1.8) | (20.8) | - | - |
| Indicated | (0.35) | (12.7) | (5.5) | (18.9) | (0.9) | (6.6) | (436) | (20.2) | (1.4) | (23.8) | - | - |
| Total | (1.01) | (15.7) | (15.1) | (15.1) | (2.9) | (8.0) | (940) | (19.2) | (3.3) | (22.0) | - | - |
| Inferred | 0.64 | 8.2 | 8.8 | 7.4 | 3.1 | 16.2 | (1,257) | (15.5) | 0.3 | 0.9 | - | - |
Mining Operations
Cerro Lindo – Net Difference in Mineral Resources between December 31, 2024, versus December 31, 2023 (on a 100% ownership basis)
| Contained Metal | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Class · Tonnage · Zinc · Copper · Silver · Lead · Gold | ||||||||||||
| (Mt)% · (kt)% · (kt)% · (koz)% · (kt)% · (koz)% | ||||||||||||
| Measured | (0.80) | (18.1) | (11.6) | (13.6) | (2.5) | (8.8) | (605) | (18.5) | (2.2) | (20.8) | - | - |
| Indicated | (0.42) | (12.8) | (6.6) | (18.9) | (1.0) | (6.7) | (524) | (20.3) | (1.7) | (23.8) | - | - |
| Total | (1.22) | (15.8) | (18.2) | (15.2) | (3.5) | (8.0) | (1,130) | (19.3) | (3.9) | (22.1) | - | - |
| Inferred | 0.76 | 8.2 | 10.4 | 7.3 | 3.7 | 16.1 | (1,513) | (15.6) | 0.3 | 0.9 | - | - |
In comparison to 2023, Cerro Lindo’s Inferred Mineral Resources increased by 8.2% in mass and by 10.4% in zinc content (kt), mainly due to brownfield drilling. In comparison to 2023, Cerro Lindo’s Measured and Indicated Mineral Resources decreased by 15.8% in mass and by 15.2% in zinc content (kt), mainly due to the conversion to Mineral Reserves.
For additional information, see the “Technical Report Summary on Cerro Lindo”, filed as Exhibit 15.1 to our annual report on Form 20-F/A for the year-ended December 31, 2020, as filed on November 4, 2021.
Vazante
The Vazante mine is an underground and open pit, polymetallic mine located about 8.5 km from the municipality of Vazante, in the state of Minas Gerais, Brazil. The approximate coordinates of the mine are 17 57’ 33” S and a longitude of approximately 46° 49’ 42” W, within Zone 23S of the Universal Transverse Mercator coordinate system (Corrego Alegre Datum) at approximately 306,000m E and 8,016,000m N and the mine area has elevations ranging from 690 to 970 meters above sea level. Access from Brasilia is via federal highway BR-040 toward Paracatu. Internal roadways connect the various mine-site components. Concentrates are trucked about 250 km to the Três Marias smelter. The closest commercial airport is located in Brasilia. The Vazante municipal airport for light aircraft is adjacent to the mine site.
History
Mineralization was initially exploited by artisanal miners during the 1950s. Mechanized open pit mining and underground mining commenced in 1969 and 1983, respectively. The current primary ore types mined are hydrothermal zinc silicates and willemite. Initial mining operations exploited supergene calamine ores and a mixture of the zinc secondary minerals hemimorphite and smithsonite, which are derived from the weathering of silicate ore.
Nexa Brazil owns 100.0% of the Vazante mine. Mineral concessions are divided into core tenements, where the known mineral deposits are located and where we have active mining operations and the surrounding exploration concessions. Nexa Brazil holds three mining concession applications, nine mining concessions, and one group of mining concessions in the core area with a total area of 2,174.5 hectares. The group of mining concessions comprises six mining concessions, totaling an area of 819.5 hectares. The Mineral Reserves and Resources are located within the limits of two mining concession applications, two exploration authorizations and four mining concessions with a total area of 1,595.7 hectares, which host the active mining operations. One mining concession (tenement # 14,840/1967), which is part of the group of mining concessions, has the potential to host zinc and lead mineralization, however it does not yet have associated mineral reserves and resources.
Nearby the main area, Nexa Brazil also holds, 27 exploration authorizations totaling 17,145.6 hectares and one right to apply for mining concession totaling 344.5 hectares, in addition to the core tenements. Nexa Brazil holds surface rights sufficient to support the current operations. Some surface rights agreements require annual payments to the owners. Two easements have been granted in support of the mining activities. Sufficient suitable land is available within the mineral tenure held by Nexa Brazil for tailings disposal, mine waste disposal, and installations such as the process plant and related mine infrastructure.
Mining Operations
Brazilian companies that hold mining concessions are subject to a royalty payment imposed by the Federal Government. For more information, see “Information on the Company—Regulatory matters—Brazilian regulatory framework—Royalties and other taxes on mining activities.”
Nexa Brazil holds all required licenses for water management and water use in the operations. Nexa Brazil has lodged renewal applications, where applicable, for the water management and use.
The Vazante Operation holds several permits in support of the current operations. The main instrument to regulate the Vazante Operation is a set of operating licenses issued by the COPAM from the state of Minas Gerais. The licenses are active, some of them are under renewal process.
The Vazante and Extremo Norte zinc deposits are epigenetic zinc silicate deposits, and Vazante is one of the largest deposits of its type worldwide. Mineralization exists within a sequence of pelitic carbonate rocks belonging to the Serra do Poço Verde formation of the Vazante group. The major structural control is the Vazante fault.
Mineral exploration activities in 2024 were focused on expanding the mineralization of known ore bodies, such as Extremo Norte, Sucuri, Vazante Sul and Lumiadeira. In 2024, we experienced drilling delays related to operational problems of drilling in carbonate rocks of the Vazante deposit, but such delays did not significantly interfere with the results of the exploration campaign. We are conducting ongoing tests to explore extensions of known mineralization, intensifying drilling in areas near the mine and identifying other areas where mineralization may be present.
In 2024, we completed approximately 8.3 km of diamond drilling across 14 drill holes, with an additional three drill holes currently in progress and expected to be concluded in 2025. The drilling was divided between exploratory and extension drilling. The focus of the near mine extension drilling was on the extension of the Vazante mine ore bodies, exploring the targets Extremo Norte, Vazante Sul and Sucuri Norte, which confirmed the mineralized system and opened lateral and depth continuity.
In 2025, Nexa intends to continue expanding the near mine orebodies, including Sucuri, Varginha, Lumiadeira and Vazante Sul, as well as converting inferred resources into indicated resources in the BDMG area, which was acquired in 2022. In 2024, we invested US$3.8 million in the Vazante brownfield program for extending the LOM, which included a drilling program and geological activities. For 2025, we have allocated a budget of US$6.4 million for the Vazante mine and expect to drill 21.0 km.
The Vazante operation consists of two mechanized underground mines, the Vazante mine and Extremo Norte Mine. The treatment plant current capacity is approximately 1.8 Mtpy, including tailings retreatment. Production drilling operations have been performed by company personnel using a variety of drilling machines throughout the history of the Vazante mine.
The Vazante underground mine has been in operation since 1983 and is a fully mechanized mine using rubber-tired diesel equipment for development and production activities. Access is through two portals for Vazante and one portal for Extremo Norte. As development progresses at Extremo Norte, a connecting drift will be established from Vazante to Extremo Norte.
All infrastructure required for the current mining and processing operations has been constructed and is operational. This includes the underground mines, access roads, power lines, water pipelines, offices and warehouses, a process plant/concentrator, conveyor systems, waste rock facilities, temporary ore stockpiles, and tailings storage facilities.
Mining Operations
The power supply to the Vazante operation is provided by one independent 138 kV transmission line that feeds the site and that can provide up to 59 MW. There are two 30/40 MVA and one 18/23 MVA transformers in the surface substation at the Vazante Operation and power is distributed to other areas of the mine at 13.8 kV and 440 V via secondary transformers to power mine equipment. There are two 700 kVA diesel generators on site to provide backup power to pump water out of the mine in case of main line interruption.
In 2024, we spent US$24.7 million on sustaining capital expenditures for this property, primarily associated with mine development, LOM extension and equipment replacement. In addition, we invested US$2.2 million in capital expenditures related to the LOM extension at Vazante, including US$0.4 million for the Vazante mine deepening project. For more information, see “Information on the Company—Mining Operations—Growth Projects—Vazante mine deepening project and other Vazante initiatives.”
The Vazante mine is in the production stage and has a treatment plant with a nominal design processing capacity of approximately 5,000 tonnes of ore per day. The table below summarizes the Vazante mine’s concentrate production, metal contained in concentrates produced and average grades for the periods indicated. Production in 2024 was lower than 2023 due to lower zinc grades.
| For the Year Ended December 31, | |||
|---|---|---|---|
| 2024 | 2023 | 2022 | |
| Treatment ore (in tonnes) | 1,769,646 | 1,633,357 | 1,524,637 |
| Average ore grade | |||
| Zinc (%) | 9.22 | 10.19 | 9.97 |
| Lead (%) | 0.28 | 0.33 | 0.33 |
| Silver (ounces per tonne) | 0.63 | 0.67 | 0.63 |
| Metal contained in concentrate production | |||
| Zinc (in tonnes) | 140,740 | 145,662 | 131,527 |
| Lead (in tonnes) | 947 | 1,449 | 1,160 |
| Silver (in oz) | 470,090 | 575,636 | 473,578 |
| Cash cost, net of by-product credits (in US$/t) | 1,079.2 | 1,315.8 | 1,214.2 |
| Cash cost, net of by-product credits (in US$/lb) | 0.49 | 0.60 | 0.55 |
| Non-Expansion Capital Expenditures (in millions of US$) | 25.4 | 29.1 | 41.9 |
The Vazante Mineral Reserves estimates are based on the definitions for Mineral Reserves in SK-1300 and the tables below are based on costs and modifying factors from the Vazante mine and Vazante Aroeira Tailings.
Vazante – Year End Mineral Reserves as of December 31, 2024 (on a 100% ownership basis)** (1)**
| Grade · Contained Metal | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Class | Tonnage (2) | Zinc | Copper | Silver | Lead | Gold | Zinc | Copper | Silver | Lead | Gold |
| (Mt) | (%) | (%) | (g/t) | (%) | (g/t) | (kt) | (kt) | (koz) | (kt) | (koz) | |
| Proven | 5.45 | 8.74 | - | 14.3 | 0.26 | - | 476.7 | - | 2,511 | 14.0 | - |
| Probable | 8.30 | 7.88 | - | 9.6 | 0.24 | - | 654.3 | - | 2,575 | 20.1 | - |
| Total | 13.75 | 8.22 | - | 11.5 | 0.25 | - | 1,131.0 | - | 5,086 | 34.1 | - |
| 1. | Subpart 1300 of Regulation S-K definitions were followed for Mineral Reserves, which also are consistent with the CIM (2014) definitions. |
| 2. | Mineral Reserves data presented in this table represents 100% of the Mineral Reserves estimates for the property. Nexa owns 100%. |
| 3. | The Qualified Person for the Mineral Reserves estimate is Mateus Gomes Ribeiro, B.Eng., MAusIMM, a Nexa employee. |
| 4. | Numbers may not add due to rounding. |
| 5. | The point of reference for Mineral Reserves in this table is mill feed materials. |
| 6. | Mineral Reserves presented in this table include Mineral Reserves from Vazante mine and Vazante Aroeira Tailings. |
Mining Operations
The Vazante Mineral Reserves estimates in the table above consider actual costs and modifying factors from the Vazante mine and Vazante Aroeira tailings, as well as operational level mine planning and budgeting. The dilution that has been applied is related to the selected mining method. The NSR cut-off value was determined using the mineral reserve metal prices, metal recoveries, transport, treatment and refining costs, as well as mine operating costs. The Vazante mine Mineral Reserves are estimated at a NSR cut-off value of US$70.52/t processed. A minimum mining width of 2.0 m. Recoveries for the Vazante mine at average head grades are 86.52% for Zn, 37.07% for Pb, and 42.00% for Ag. The Vazante Aroeira Tailings Mineral Reserves estimates in the table above consider actual costs and modifying factors from the Vazante Aroeira tailings, as well as operational level TSF reclaiming plan and budgeting. The Vazante Aroeira Tailings Mineral Reserves are estimated at a NSR cut-off value of US$28.42/t processed. A minimum mining unit of 10m x 10m x 2m was applied. Recoveries for Vazante Aroeira Tailings at average head grades are 67.98% for Zn, 36.00% for Pb, and 42.00% for Ag. Metallurgical recoveries are accounted for in NSR calculations based on historical processing data and are variable as a function of head grade. Long-term metal prices used for Mineral Reserves are based on consensus and long-term forecasts from banks, financial institutions and other sources. Mineral Reserves estimates are based on average long-term metal prices of zinc: US$2,864.90/t (US$1.30/lb); lead: US$2,097.45/t (US$0.95/lb); and silver: US$24.83/oz. The current LOM plan continues to 2032.
Vazante – Net Difference in Mineral Reserves between December 31, 2024, versus December 31, 2023 (on a 100% ownership basis)
| Contained Metal | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Class · Tonnage · Zinc · Copper · Silver · Lead · Gold | ||||||||||||
| (Mt)% · (kt)% · (kt)% · (koz)% · (kt)% · (koz)% | ||||||||||||
| Proven | (0.03) | (0.6) | (63.1) | (11.7) | - | - | (512.2) | (16.9) | 1.5 | 12.1 | - | - |
| Probable | 0.34 | 4.3 | 17.6 | 2.8 | - | - | 54.1 | 2.1 | 3.5 | 21.4 | - | - |
| Total | 0.31 | 2.3 | (43.5) | (3.9) | - | - | (458.1) | (8.3) | 5.1 | 17.4 | - | - |
In comparison to 2023, Vazante’s Mineral Reserves increased by 2.3% in mass, mainly due to narrower orebodies with minimum operational width of 2m and decreased by 3.9% in zinc content (kt), mainly due to lower grades, following a review on the overbreak (i.e., the area mined outside the planned area) in our operations, which added waste to the mined tonnes, mined grade being above the average reserve grade and new drilling adding lower zinc grades. Mineral Reserve depletion during 2024 accounted for 1.8Mt containing 163.0kt of zinc.
Vazante – Year End Mineral Resources as of December 31, 2024 (on an 100% ownership basis)(1)
| Grade · Contained Metal | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Class | Tonnage (2) | Zinc | Copper | Silver | Lead | Gold | Zinc | Copper | Silver | Lead | Gold |
| (Mt) | (%) | (%) | (g/t) | (%) | (g/t) | (kt) | (kt) | (koz) | (kt) | (koz) | |
| Measured | 0.46 | 8.99 | - | 16.2 | 0.30 | - | 41.4 | - | 240 | 1.4 | - |
| Indicated | 1.43 | 10.15 | - | 4.9 | 0.09 | - | 145.1 | - | 225 | 1.3 | - |
| Total | 1.89 | 9.87 | - | 7.7 | 0.14 | - | 186.5 | - | 465 | 2.7 | - |
| Inferred | 13.36 | 9.84 | - | 12.2 | 0.21 | - | 1,314.4 | - | 5,068 | 27.4 | - |
| 1. | Subpart 1300 of Regulation S-K definitions were followed for Mineral Resources, which also are consistent with the CIM (2014) definitions. |
| 2. | Mineral Resources data presented in this table represents 100% of the Mineral Resources estimates for the property. Nexa owns 100% of property. |
| 3. | Mineral Resources are reported exclusive of those Mineral Resources that were converted to Mineral Reserves, and Mineral Resources are not Mineral Reserves and do not have demonstrated economic viability. |
| 4. | The Qualified Person for the Mineral Resources estimate is José Antonio Lopes, B.Geo., FAusIMM(Geo), a Nexa employee. |
| 5. | Numbers may not add due to rounding. |
| 6. | The point of reference for Mineral Resources in this table is mill feed materials. |
| 7. | Mineral Resources presented in this table include Mineral Resources from the Vazante mine and Vazante Aroeira Tailings. |
Mining Operations
The Vazante Mineral Resources estimates in the table above were completed using Datamine and Leapfrog software. The Mineral Resources at Vazante comprise three styles of mineralization. The first style of mineralization is represented by the hypogene (willemite) mineralized zones that are found in the underground portions of the Vazante and Extremo Norte deposits. The second style of mineralization is represented by the supergene (calamine) mineralized zones found in the Cava 3A, Matas dos Paulistas, and Braquiara areas of the Extremo Norte and Vazante deposits. This supergene (calamine) mineralization is referred to at the Vazante Operation as calamine mineralization and comprises a mixture of smithsonite and hemimorphite minerals. The third type of mineralization comprises tailings that are contained within the Aroeira TSF. The material found in the Aroeira tailings comprise a mixture of hypogene (willemite) and supergene (calamine) minerals. Mineral Resources estimates for the underground hypogene (willemite) mineralization are prepared within reporting panels using the native functions and workflows available through the DSO software package considering spatial continuity, a minimum width of 3.0 m and a NSR cut-off value of US$70.52/t for Hypogene Mineralization (willemite). The Mineral Resources estimates for the supergene (calamine) mineralization are prepared using an open pit shell that considers appropriate metal prices, mining costs, metallurgical recoveries and geotechnical considerations with NSR cut-off value of US$27.91/t for soil and US$32.92/t for fresh rock and transition material. The Mineral Resources estimates for the tailings at Vazante are reported considering the material with a NSR value of greater than US$28.42/t which lies above the original topographic surface. Mineral Resources estimates are based on average long-term metal prices for willemite and Aroeira TSF of zinc: US$3,294.64/t (US$1.49/lb); lead: US$2,412.07/t (US$1.09/lb); and silver: US$28.55/oz, and for calamine of zinc: US$3,250.30/t (US$1.47/lb). Metallurgical recoveries are accounted for in NSR calculations based on historical processing data and are variable as a function of head grade. Recoveries at LOM average: hypogene head grades are 86.52% for Zn, 37.07% for Pb, and 42.0% for Ag, supergene (calamine) is 55.0% for Zn, and tailings are 67.98% for Zn, 36.00% for Pb, and 42.00% for Ag.
Vazante – Net Difference in Mineral Resources between December 31, 2024 versus December 31, 2023 (on an 100% ownership basis)
| Contained Metal | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Class · Tonnage · Zinc · Copper · Silver · Lead · Gold | ||||||||||||
| (Mt)% · (kt)% · (kt)% · (koz)% · (kt)% · (koz)% | ||||||||||||
| Measured | (0.02) | (4.0) | 1.1 | 2.8 | - | - | 49 | 25.7 | 0.2 | 16.9 | - | - |
| Indicated | 0.03 | 2.1 | 10.1 | 7.4 | - | - | 43 | 23.6 | 0.2 | 18.1 | - | - |
| Total | 0.01 | 0.5 | 11.2 | 6.4 | - | - | 92 | 24.8 | 0.4 | 17.5 | - | - |
| Inferred | (0.07) | (0.5) | (24.4) | (1.8) | - | - | (388) | (7.1) | (1.7) | (5.9) | - | - |
In comparison to 2023, Vazante’s Inferred Mineral Resources decreased by 0.5% in mass and by 1.8% in zinc content (kt), mainly due to the recategorization to Measured and Indicated and furthermore the conversion to Mineral Reserves. In comparison to 2023, Vazante’s Measured and Indicated Mineral Resources increased by 0.5% in mass and by 6.4% in zinc content (kt), mainly due to an increase in grade as a result of infill drilling.
For additional information, see the “Technical Report Summary on Vazante”, filed as Exhibit 15.3 to our annual report on Form 20-F/A for the year-ended December 31, 2020, as filed on November 4, 2021.
Cerro Pasco Complex
The Cerro Pasco Complex consists of the El Porvenir underground mine, which produces zinc, copper, lead, silver and gold; the Atacocha San Gerardo open pit mine, producing zinc, lead, silver and gold; and the Atacocha underground mine, which has been suspended since 2020 and remains under care and maintenance due to our efforts to reduce costs and improve our operational efficiency.
The Atacocha and El Porvenir mines are located in Peru, specifically in the province of Pasco, which is a region recognized for its intensive mineral economic activities, where many polymetallic mines have been operating for several decades.
El Porvenir is an underground mine with multiple accesses and a shaft where the mined ore is extracted and where workers and inputs are also transported. There are multiple accesses to the Atacocha underground mine from the surface and the mine is currently connected to the El Porvenir mine through two active tunnels located at 4070 and 3300 levels. These tunnels are used by operators of heavy mine equipment and conventional trucks, as well as for transporting mining crews between the Atacocha surface and the El Porvenir mine.
Mining Operations
Currently, production from the Atacocha San Gerardo open pit mine feeds the Atacocha processing plant with a nominal throughput capacity of 4,400 tonnes of ore per day, while production from the El Porvenir underground mine feeds the El Porvenir processing plant with a nominal throughput capacity of 6,500 tonnes of ore per day. The Atacocha processing plant is expected to be decommissioned by 2027, when the Atacocha San Gerardo pit reaches the end of its mine life based on our current depletion schedule.
Integration Project
The Cerro Pasco Complex integration project (“Integration Project”) involves the continued integration of the El Porvenir and Atacocha underground mines. The Cerro Pasco Complex is a material property for the purposes of S-K 1300 comprising the two mines, El Porvenir and Atacocha. The Integration Project is intended to continue to capture synergies between the two mining operations, as a result of their proximity and operational similarities, with ore from both the underground mines being processed at the El Porvenir processing plant. The goal of the Integration Project is to achieve cost and investment savings, thereby reducing the environmental footprint and extending the combined LOM of the two mines.
The Integration Project has been developed over the past few years. The first stage involved the administrative integration of both mines, completed in 2014. The second stage, completed in 2015, involved the integration of the tailings disposal system, which allowed the Atacocha plant to send its tailings to the El Porvenir dam in the short-term, thus contributing to the reduction of our environmental footprint. Operations of the integrated tailings disposal system began in 2016. The third stage, completed in 2016, involved the construction of a new 138-kilovolt (“kV”) energy transmission line connecting both mines, replacing the two previous 50 kV transmission lines. The fourth stage, concluded in 2019, involved the development of a 3.5 km tunnel connecting both underground mines, allowing us to initiate exploration programs in the integration zone between the two mines.
In 2021, modernization and debottlenecking studies to assess the mine deepening and the extension of the LOM of El Porvenir were postponed due to Nexa’s capital allocation strategy and the reassessment of the integration with the Atacocha underground mine. In 2022, we advanced the Integration Project with an optimization study to evaluate the increase in capacity of our tailings and El Porvenir shaft, in addition to enhancing the El Porvenir processing plant to potentially increase production and extend the LOM of both mines.
In 2023, we continued to advance the technical studies of the Integration Project, aiming to develop a robust organic growth option for Nexa. The technical studies for the Integration Project covered diverse areas, from mine planning to projects to sustain and expand production, such as studies for underground interconnection, shaft upgrade, engineering assessments, and key routes to increase capacity to provide a long-term solution for tailings disposal. A Front-End Loading 3 (“FEL3”) study to increase the El Porvenir hoisting was completed in the first quarter of 2023 and a FEL3 tailings pumping system study was also completed in the second quarter of 2023. As a result of the advancements in the technical studies in 2023, we increased the overall Mineral Reserves of the El Porvenir and Atacocha mines in the Cerro Pasco Complex, as of December 31, 2023. For additional information on the increase of Mineral Reserves, see “Information on the Company—Mining operations—El Porvenir—Mineral Reserves and Mineral Resources” and “Information on the Company— Mining operations—Atacocha—Mineral Reserves and Mineral Resources”
In 2024, Nexa achieved important milestones in the Integration Project. During the fourth quarter of 2024, our Board of Directors, through the Finance Committee, approved the first phase of the Integration Project – the tailings pumping and piping system, following a recommendation from the SCP Committee. This phase aims to expand tailings storage capacity at the Cerro Pasco Complex, thereby extending substantially the operational life of the site. Additionally, we developed an investment plan consisting of two phases that includes constructing a tailings treatment plant and its auxiliary structures at El Porvenir, and the second involves installing a 6 km pipeline (mostly underground) to connect El Porvenir to Atacocha’s tailings storage facility. This initiative will enable the Cerro Pasco Complex to operate for over a decade and represents a pivotal step toward sustainability.
Mining Operations
Construction of the tailings pumping and piping system is expected to begin in the second quarter of 2025. As part of the project’s first phase, investments to raise the El Porvenir tailings dam and expand Atacocha’s tailings storage capacity are already in progress. Studies for the second phase of the project, which includes an additional underground connection of the mines and the El Porvenir shaft upgrade, are progressing well, and are expected to be completed by the third quarter of 2025.
The capital expenditures for the tailings pumping system are estimated to be between US$85 million and US$90 million, with investments planned from 2025 to 2026, with operations expected to commence in 2027. During the first phase, we intend to upgrade the tailings facilities at both El Porvenir and Atacocha, as well as improve water and effluent treatment systems, with construction planned for 2027-2028 following the completion of environmental impact assessments. In the second phase, we aim to build an additional 2.3 kilometers underground tunnel at a deeper level to connect the El Porvenir and Atacocha mines and upgrade the El Porvenir shaft, which is expected to unlock access to high-grade mineral resources. Support activities, such as technical reviews, environmental studies, and community engagement, are also progressing as planned. We are confident in the long-term value this project will generate for Nexa and remain focused on its successful execution.
Overall, the Integration Project plan includes several key initiatives, including: (i) the restart and rehabilitation of the Atacocha underground mine, revitalizing operations to improve production capacity; (ii) the development of an additional 2.3 km long connection tunnel (Tunnel 2900), which will connect the Atacocha underground mine to the base of the El Porvenir (Picasso) shaft, allowing ore hoisting and processing at the El Porvenir plant; (iii) the expansion of the Picasso shaft capacity to support production and ore extraction from both underground mines; (iv) the closure of the Atacocha processing plant, following the depletion of Atacocha’s open pit Mineral Reserves in 2027, resulting in operations being consolidated at El Porvenir; and (v) the construction of a new tailings pumping and pipeline system, establishing a long-term tailings disposal solution by transporting the tailings from the El Porvenir processing plant to the Atacocha tailings storage facility, extending the operational life of the combined mines. We also are advanced on other work fronts related to the Integration Project, including the process to obtain the required environmental studies and permits.
For further information about our operations, infrastructure, production, and Mineral Reserves and Mineral Resources at the El Porvenir and Atacocha mines, see the Technical Report Summary on the Cerro Pasco Complex Integration, filed as Exhibit 15.2 to Nexa’s annual report on Form 20-F for the year-ended December 31, 2023, as filed on March 27, 2024.
El Porvenir
The El Porvenir mine is an underground, polymetallic mine (located in the Cerro Pasco Complex) in the central Andes mountains region of Peru, specifically in the district of San Francisco de Asís de Yarusyacán, in the province of Pasco, Peru. The approximate coordinates of the mine are 367600m E, 8826850m N, using the Universal Transverse Mercator WGS84 datum, Z18S and the mine site is located at an average elevation of 4,200 meters above sea level. The mine is situated at kilometer 340 of the Carretera Central Highway (Lima—Huánuco route), 13 km from the city of Cerro de Pasco. The mine is located in the Central Cordillera zone, which contains the communities of Parán, Lacsanga and Santo Domingo de Apache.
History
The El Porvenir mine began its operation as small scale artisanal mine in 1949. We have been investing in the mine since then, with a current treatment plant capacity of 6,500 tonnes of ore per day. In 2014, we commenced the integration process with the Atacocha mine, as described above in "Information on the Company—Mining Operations—Cerro Pasco Complex—Integration Project.
The El Porvenir mine is operated by Nexa Resources El Porvenir S.A.C., a wholly-owned subsidiary of Nexa Peru.
Mining Operations
The El Porvenir mine has a total of 25 concessions covering approximately 4,846.7 hectares, as well as a beneficiation plant, “Acumulacion Aquiles 101”. With respect to the surface property at El Porvenir mine, there is a mining site of 450.8 hectares, where the mining concession is located, as well as additional surface property where tailings dams/ponds, camps sites and other ancillary infrastructure are located.
Mining operations at the El Porvenir mine are subject to certain royalties payable by Nexa Resources El Porvenir S.A.C. For more information, see “Information on the Company—Regulatory matters—Peruvian regulatory framework—Royalties and other taxes on mining activities.”
The El Porvenir Mine holds several permits in support of the current operations. The permits are Directorial Resolutions issued by the Peruvian authorities upon approval of mining environmental management instruments filed by the mining companies. Nexa Peru maintains an up-to-date record of the legal permits obtained to date.
The El Porvenir mine is a typical skarn deposit. The mineralization occurs within the contact of the upper Triassic limestone (i.e., exoskarn) and the granodioritic-dacitic intrusive rocks (i.e., endoskarn). There are also recognized veins and replacement manto type, minor disseminated mineralization may occur within the intrusive units. West of the Milpo-Atacocha fault within the Goyllarisquizga Group, mineralization is characterized as veins and disseminations.
Four groups of vein/mineralized structures are reported. Structurally controlled veins are sub-vertical up to 150 meters long, with a vertical extent of 350 meters. Economic mineralogy is mostly comprised of galena, sphalerite, and tetrahedrite, as well as variable and lesser pyrite, quartz and rhodochrosite.
Throughout 2024, the exploration program at El Porvenir was focused on drilling in mineralized zones in the Integration Project, seeking to evaluate the mineralization continuity in strike and at depth, with the goal of increasing mineral resources to expand the life of the El Porvenir and Atacocha mines. In 2024, we drilled 19 drill holes totaling 10.3 km of exploration drilling. The exploration drilling strategy continues to focus on expanding mineral resources and mineral reserves in Integration Project.
In 2025, we will focus our efforts on expanding the El Porvenir LOM with conversion drilling at the Integration Project. This initiative aims to upgrade mineral resources, supporting the long-term sustainability and operational efficiency of the mining complex.
We spent approximately US$1.8 million on the El Porvenir brownfield program in 2024, including the drilling program and geological activities. We have budgeted US$3.3 million for 2025 activities, and we expect to drill 13.7 km in 2025.
Most of the exploration is generally conducted simultaneously with underground development, which involves diamond core drilling and channel sampling following underground drifting.
The El Porvenir mine site consists of an underground mine, tailings pond, waste rock stockpiles, a process facility with associated laboratory and maintenance facilities and maintenance buildings for underground and surface equipment. Facilities and structures include a warehouse, office, change house facilities, main shaft, ventilation shaft, backfill plant, explosives storage area, hydroelectric power generation, power lines and substation, fuel storage tanks, a warehouse and laydown area and a permanent accommodation camp.
The electrical power supply for the mine comes from two sources: connection to the SEIN national power grid by a main substation located near the site, and the Candelaria Hydro, which consists of three turbines connected to the mine through the main substation by a transmission line. All other loads of the mine are fed from the main substation through overhead power lines. These power lines are used to deliver power to various locations to support activities during operation of the mine.
Mining Operations
Site roads include main roads suitable for use by mining trucks that transport concentrates to Lima and service roads for use by smaller vehicles. The site roads are used by authorized mine personnel and equipment, with access controlled by Nexa Peru. An approximately 15-to-20-kilometer network of service roads was constructed to provide access to the underground mine, processing plant, tailings facility, waste rock stockpile, mine offices, workshops, mine camps and other surface infrastructure.
In 2024, we spent US$59.7 million on sustaining capital expenditures for this property, primarily associated with mine development, TSF, equipment replacement and other major infrastructure.
The El Porvenir mine is in the production stage and has a treatment plant capacity of 6,500 tonnes of ore per day. The table below summarizes the El Porvenir mine’s concentrate production, metal contained in concentrates produced and average grades for the periods indicated. Production in 2024 was lower than 2023 due to lower treated lower zinc grades.
| For the Year Ended December 31, | |||
|---|---|---|---|
| 2024 · 2023 · 2022 | |||
| Treatment ore (in tonnes) | 2,205,478 | 2,220,011 | 2,111,961 |
| Average ore grade | |||
| Zinc (%) | 2.61 | 2.86 | 2.80 |
| Copper (%) | 0.14 | 0.16 | 0.16 |
| Lead (%) | 1.44 | 1.37 | 1.34 |
| Silver (ounces per tonne) | 2.50 | 2.34 | 2.46 |
| Gold (ounces per tonne) | 0.010 | 0.011 | 0.012 |
| Metal contained in concentrate production | |||
| Zinc (in tonnes) | 50,637 | 55,825 | 51,561 |
| Copper (in tonnes) | 292 | 355 | 266 |
| Lead (in tonnes) | 26,805 | 24,937 | 23,195 |
| Silver (in oz) | 4,641,676 | 4,270,463 | 4,195,649 |
| Gold (in oz) | 7,974 | 8,696 | 9,204 |
| Cash Cost, net of by-product credits (in US$/t) | 185.4 | 630.6 | 727.7 |
| Cash Cost, net of by-product credits (in US$/lb) | 0.08 | 0.29 | 0.33 |
| Non-Expansion Capital Expenditures (in millions of US$) | 60.5 | 68.6 | 36.7 |
The El Porvenir Mineral Reserves estimates are based on the definitions for Mineral Reserves in SK-1300 and the tables below are based on costs and modifying factors from the El Porvenir mine.
El Porvenir – Year End Mineral Reserves as of December 31, 2024 (on an 83.55% Nexa attributable ownership basis)(1)
| Grade · Contained Metal | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Class | Tonnage (2) | Zinc | Copper | Silver | Lead | Gold | Zinc | Copper | Silver | Lead | Gold |
| (Mt) | (%) | (%) | (g/t) | (%) | (g/t) | (kt) | (kt) | (koz) | (kt) | (koz) | |
| Proven | 3.42 | 4.11 | 0.25 | 76.2 | 1.29 | - | 140.5 | 8.5 | 8,384 | 44.2 | - |
| Probable | 9.30 | 4.16 | 0.23 | 70.9 | 1.14 | - | 387.2 | 21.8 | 21,211 | 106.2 | - |
| Total | 12.72 | 4.15 | 0.24 | 72.3 | 1.18 | - | 527.2 | 30.3 | 29,595 | 150.4 | - |
| 1. | Subpart 1300 of Regulation S-K definitions were followed for Mineral Reserves, which also are consistent with the CIM (2014) definitions. |
| 2. | Mineral Reserves data presented in this table are reported on 83.55% Nexa attributable ownership. |
| 3. | The Qualified Person for the Mineral Reserves estimate is Renzo Suarez, B.Eng., MAusIMM, a Nexa employee. |
| 4. | Numbers may not add due to rounding. |
| 5. | The point of reference for Mineral Reserves in this table is mill feed materials. |
Mining Operations
El Porvenir – Year End Mineral Reserves as of December 31, 2024 (on a 100% ownership basis)(1)
| Grade · Contained Metal | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Class | Tonnage (2) | Zinc | Copper | Silver | Lead | Gold | Zinc | Copper | Silver | Lead | Gold |
| (Mt) | (%) | (%) | (g/t) | (%) | (g/t) | (kt) | (kt) | (koz) | (kt) | (koz) | |
| Proven | 4.10 | 4.11 | 0.25 | 76.2 | 1.29 | - | 168.2 | 10.2 | 10,035 | 52.9 | - |
| Probable | 11.13 | 4.16 | 0.23 | 70.9 | 1.14 | - | 463.4 | 26.1 | 25,387 | 127.1 | - |
| Total | 15.23 | 4.15 | 0.24 | 72.3 | 1.18 | - | 631.6 | 36.3 | 35,442 | 180.1 | - |
| 1. | Subpart 1300 of Regulation S-K definitions were followed for Mineral Reserves, which also are consistent with the CIM (2014) definitions. |
| 2. | Mineral Reserves data presented in this table represents 100% of the Mineral Reserves estimates for the property. Nexa owns 83.55%. |
| 3. | The Qualified Person for the Mineral Reserves estimate is Renzo Suarez, B.Eng., MAusIMM, a Nexa employee. |
| 4. | Numbers may not add due to rounding. |
| 5. | The point of reference for Mineral Reserves in this table is mill feed materials. |
The El Porvenir Mineral Reserves estimates in the table above were prepared using DSO software, mine design and scheduling software. Mining methods used are Cut-and-Fill (“C&F”) mining, using unconsolidated rock fill and hydraulic backfill, and Sublevel Stope (“SLS”) using unconsolidated rock fill. NSR values were calculated using mineral reserve metal prices, metallurgical recovery and consideration of smelter terms, including revenue from payable metals, price participation, penalties, smelter losses, transportation, treatment, refining and sales charges. A minimum mining width of 5.0 m for C&F mining and 4.0 m for SLS mining were used for reserves shapes and development design and are reported to be inclusive of extraction losses and dilution. Mineral Reserves were estimated at a NSR cut-off values ranging from US$68.31/t to US$71.59/t for SLS areas, and US$70.31/t to US$73.58/t for C&F areas depending on the zone. A number of incremental material (with values between US$44.44/t and US$70.31/t for SLS and values between US$46.44/t and US$68.31/t for C&F mining) was included in the estimates. Mineral Reserves estimates are based on average long-term metal prices of zinc: US$2,864.90/t (US$1.30/lb); copper: US$9,095.61/t (US$4.13/lb); lead: US$2,097.45/t (US$0.95/lb); and silver: US$24.83/oz. Metallurgical recoveries are accounted for in NSR calculations based on historical processing data and are variable as a function of head grade. Recoveries at LOM average head grades are 89.23% for Zn, 15.03% for Cu, 79.99% for Pb, and 62.92% for Ag. The current LOM plan continues to 2034.
El Porvenir – Net Difference in Mineral Reserves between December 31, 2024, versus December 31, 2023 (on an 83.55% Nexa attributable ownership basis)
| Contained Metal | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Class · Tonnage · Zinc · Copper · Silver · Lead · Gold | ||||||||||||
| (Mt)% · (kt)% · (kt)% · (koz)% · (kt)% · (koz)% | ||||||||||||
| Proven | 0.15 | 4.7 | 6.7 | 5.0 | 0.6 | 7.1 | 477 | 6.0 | 2.2 | 5.2 | - | - |
| Probable | 0.34 | 3.8 | 18.5 | 5.0 | 1.8 | 8.8 | 452 | 2.2 | 1.6 | 1.5 | - | - |
| Total | 0.49 | 4.0 | 25.2 | 5.0 | 2.3 | 8.3 | 930 | 3.2 | 3.8 | 2.6 | - | - |
Mining Operations
El Porvenir – Net Difference in Mineral Reserves between December 31, 2024, versus December 31, 2023 (on a 100% ownership basis)
| Contained Metal | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Class · Tonnage · Zinc · Copper · Silver · Lead · Gold | ||||||||||||
| (Mt)% · (kt)% · (kt)% · (koz)% · (kt)% · (koz)% | ||||||||||||
| Proven | 0.18 | 4.6 | 7.9 | 5.0 | 0.7 | 7.0 | 563 | 5.9 | 2.6 | 5.1 | - | - |
| Probable | 0.40 | 3.7 | 21.7 | 4.9 | 2.1 | 8.7 | 521 | 2.1 | 1.8 | 1.5 | - | - |
| Total | 0.58 | 3.9 | 29.6 | 4.9 | 2.8 | 8.3 | 1,084 | 3.2 | 4.4 | 2.5 | - | - |
In comparison to 2023, El Porvenir’s Mineral Reserves increased by 3.9% in mass and by 4.9% in zinc content (kt). The increase in mass was mainly due to mineral resources additions as a result of the 2024 diamond drilling campaign. Mineral Reserve depletion during 2024 accounted for 2.2Mt containing 50.6 kt of zinc.
El Porvenir – Year End Mineral Resources as of December 31, 2024 (on an 83.55% Nexa Attributable ownership basis)(1)
| Grade · Contained Metal | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Class | Tonnage (2) | Zinc | Copper | Silver | Lead | Gold | Zinc | Copper | Silver | Lead | Gold |
| (Mt) | (%) | (%) | (g/t) | (%) | (g/t) | (kt) | (kt) | (koz) | (kt) | (koz) | |
| Measured | 0.68 | 3.12 | 0.24 | 55.6 | 0.96 | - | 21.3 | 1.6 | 1,220 | 6.6 | - |
| Indicated | 3.38 | 3.19 | 0.20 | 59.7 | 0.92 | - | 107.8 | 6.6 | 6,481 | 31.1 | - |
| Total | 4.06 | 3.18 | 0.20 | 59.0 | 0.93 | - | 129.1 | 8.3 | 7,701 | 37.7 | - |
| Inferred | 12.92 | 3.67 | 0.22 | 81.6 | 1.33 | - | 474.0 | 28.9 | 33,879 | 171.7 | - |
| 1. | Subpart 1300 of Regulation S-K definitions were followed for Mineral Resources, which also are consistent with the CIM (2014) definitions. |
| 2. | Mineral Resources Tonnes and Contained Metal presented in this table are reported on 83.55% Nexa attributable ownership. |
| 3. | Mineral Resources are reported exclusive of those Mineral Resources that were converted to Mineral Reserves, and Mineral Resources are not Mineral Reserves and do not have demonstrated economic viability. |
| 4. | The Qualified Person for the Mineral Resources estimate is Jerry Huaman Abalos, B.Geo., MAusIMM CP(Geo), a Nexa employee. |
| 5. | Numbers may not add due to rounding. |
| 6. | The point of reference for Mineral Resources in this table is mill feed materials. |
El Porvenir – Year End Mineral Resources as of December 31, 2024 (on a 100% ownership basis)(1)
| Grade · Contained Metal | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Class | Tonnage (2) | Zinc | Copper | Silver | Lead | Gold | Zinc | Copper | Silver | Lead | Gold |
| (Mt) | (%) | (%) | (g/t) | (%) | (g/t) | (kt) | (kt) | (koz) | (kt) | (koz) | |
| Measured | 0.82 | 3.12 | 0.24 | 55.6 | 0.96 | - | 25.5 | 2.0 | 1,461 | 7.8 | - |
| Indicated | 4.04 | 3.19 | 0.20 | 59.7 | 0.92 | - | 129.0 | 7.9 | 7,757 | 37.2 | - |
| Total | 4.86 | 3.18 | 0.20 | 59.0 | 0.93 | - | 154.5 | 9.9 | 9,217 | 45.1 | - |
| Inferred | 15.46 | 3.67 | 0.22 | 81.6 | 1.33 | - | 567.3 | 34.6 | 40,550 | 205.5 | - |
| 1. | Subpart 1300 of Regulation S-K definitions were followed for Mineral Resources, which also are consistent with the CIM (2014) definitions. |
| 2. | Mineral Resources data presented in this table represents 100% of the Mineral Resources estimates for the property. Nexa owns 83.55%. |
| 3. | Mineral Resources are reported exclusive of those Mineral Resources that were converted to Mineral Reserves, and Mineral Resources are not Mineral Reserves and do not have demonstrated economic viability. |
| 4. | The Qualified Person for the Mineral Resources estimate is Jerry Huaman Abalos, B.Geo., MAusIMM CP(Geo), a Nexa employee. |
| 5. | Numbers may not add due to rounding. |
| 6. | The point of reference for Mineral Resources in this table is mill feed materials. |
The El Porvenir Mineral Resources estimates in the table above were completed using Datamine and Leapfrog software. Wireframes for geology and mineralization were constructed in Leapfrog based on geology sections, assay results, lithological information, underground mapping and structural data. Assays were capped to various levels based on exploratory data analysis and then composited to 1.0 m lengths. Wireframes were filled with blocks and sub-celling at wireframe boundaries. Blocks were interpolated with grade using the OK and ID 3 interpolation algorithms. Block estimates were validated using industry standard validation techniques. Classification of blocks used distance-based and mineralization continuity criteria. Mineral Resources are reported using all the material within resource shapes generated in DSO software, satisfying minimum mining width of 4.0 m in areas with C&F stopes shapes and 3.0 m for SLS stopes. The Mineral Resources are estimated at a NSR cut-off grade values ranging from US$68.31/t to US$71.59/t for SLS areas and US$70.31/t to US$73.58/t for C&F areas depending on the zone. Mineral Resources estimates are based on average long-term metal prices of zinc: US$3,294.64/t (US$1.49/lb); copper: US$10,459.95/t (US$4.74/lb); lead: US$2,412.07/t (US$1.09/lb); and silver: US$28.55/oz. Metallurgical recoveries are accounted for in NSR calculations based on historical processing data and are variable as a function of head grade. Recoveries at LOM average head grades are 89.23% for Zn, 15.03% for Cu, 79.99% for Pb, and 62.92% for Ag.
Mining Operations
El Porvenir – Net Difference in Mineral Resources between December 31, 2024, versus December 31, 2023 (on an 83.55% Nexa attributable ownership basis)
| Contained Metal | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Class · Tonnage · Zinc · Copper · Silver · Lead · Gold | ||||||||||||
| (Mt)% · (kt)% · (kt)% · (koz)% · (kt)% · (koz)% | ||||||||||||
| Measured | 0.13 | 23.9 | 2.2 | 11.5 | 0.1 | 9.5 | 198 | 19.3 | 1.3 | 24.7 | - | - |
| Indicated | 0.69 | 25.6 | 20.4 | 23.3 | 1.3 | 23.9 | 1,021 | 18.7 | 5.1 | 19.4 | - | - |
| Total | 0.82 | 25.3 | 22.6 | 21.2 | 1.4 | 20.8 | 1,218 | 18.8 | 6.4 | 20.3 | - | - |
| Inferred | 3.69 | 39.9 | 120.3 | 34.0 | 6.8 | 30.8 | 9,277 | 37.7 | 49.8 | 40.9 | - | - |
El Porvenir – Net Difference in Mineral Resources between December 31, 2024 versus December 31, 2023 (on a 100% ownership basis)
| Contained Metal | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Class · Tonnage · Zinc · Copper · Silver · Lead · Gold | ||||||||||||
| (Mt)% · (kt)% · (kt)% · (koz)% · (kt)% · (koz)% | ||||||||||||
| Measured | 0.16 | 23.8 | 2.6 | 11.4 | 0.2 | 9.4 | 236 | 19.2 | 1.5 | 24.6 | - | - |
| Indicated | 0.82 | 25.5 | 24.3 | 23.2 | 1.5 | 23.8 | 1,217 | 18.6 | 6.0 | 19.3 | - | - |
| Total | 0.98 | 25.2 | 26.9 | 21.1 | 1.7 | 20.7 | 1,452 | 18.7 | 7.6 | 20.2 | - | - |
| Inferred | 4.40 | 39.8 | 143.7 | 33.9 | 8.1 | 30.7 | 11,079 | 37.6 | 59.5 | 40.8 | - | - |
In comparison to 2023, El Porvenir’s Inferred Mineral Resources increased by 39.8% in mass and by 33.9% in zinc content (kt), mainly due to exploration brownfield drilling. In comparison to 2023, El Porvenir’s Measured and Indicated Mineral Resources increased by 25.2% in mass and by 21.1% in zinc content (kt), mainly due to infill drilling.
For additional information, see the Technical Report Summary on the Cerro Pasco Complex Integration, filed as Exhibit 15.2 to Nexa’s annual report on Form 20-F for the year-ended December 31, 2023, as filed on March 27, 2024.
Atacocha
Atacocha is a polymetallic underground and open pit mine (located in the Cerro Paso Complex) in the district of San Francisco de Asís de Yarusyacán, in the province of Pasco, Peru. The property is located at approximate coordinates of 367160m E, 8,830,400m N, using the UTMWGS84 datum, Z18S and approximately 4,050 meters above sea level.
Mining Operations
History
The Atacocha mine began its operation as small-scale artisanal mine in 1936. We have been investing in the mine since then and, in 2012, production reached its current capacity of 4,500 tonnes per day. In 2014, we commenced the Integration Project with the El Porvenir mine, as described above in “Information on the Company—Mining operations—Cerro Pasco Complex—Integration Project.” In 2020, in response to COVID-19 and based on our cost management strategy, the Integration Project was temporarily suspended and Atacocha’s underground operations were not resumed after the mandatory restriction period from the Peruvian Government was lifted in mid-2020. As of the date of this annual report, the Atacocha underground mine is suspended under care and maintenance. In the fourth quarter of 2024, our Board of Directors, through the Finance Committee approved the first phase of the Integration Project – the tailings pumping and piping system, following the recommendation from the SCP Committee.
The Atacocha mine is operated by Nexa Resources Atacocha S.A.A., a subsidiary of Nexa Peru.
The Atacocha mine has a total of 147 concessions covering approximately 2,872.5 hectares, as well as a beneficiation plant, “Chicrin N° 2.” With respect to the surface property at the Atacocha mine, there is a mining site of 1,343.0 hectares, where the mining concession is located, as well as additional surface property where tailings dams/ponds, camps sites and other ancillary infrastructure are located. There are royalties payable in respect of mining operations at the Atacocha mine for the mining concessions held by Nexa Resources Atacocha S.A.A. For more information, see “Information on the Company—Regulatory matters—Peruvian regulatory framework—Royalties and other taxes on mining activities.”
The Atacocha mine holds a number of permits in support of the current operations. The permits are Directorial Resolutions issued by the Peruvian authorities upon approval of mining environmental management instruments filed by the mining companies. Nexa Peru maintains an up-to-date record of the legal permits obtained to date.
Atacocha operates two mines: the Atacocha underground mine and the San Gerardo open pit mine. The underground mine is currently suspended due to our efforts to reduce costs and improve our operational efficiency and remains under care and maintenance. However, mining continues in the San Gerardo open pit mine. Both mining operations feed the Atacocha processing plant.
In 2024, we spent approximately US$0.4 million on the Atacocha brownfield program for exploration maintenance. We have budgeted US$0.3 million for maintenance in 2025.
In 2024, we spent US$10.8 million on sustaining capital expenditures for this property, primarily associated with mine development, equipment replacement and other major infrastructure.
In February 2024 protest activities by the Joraoniyoc community blocked road access to the Atacocha San Gerardo open pit mine and suspended operations for approximately three days. Mining activities were limited to critical operations with a minimum workforce to ensure appropriate maintenance, safety and security. Despite the blockage, the Atacocha mine operated at high levels of capacity utilization rates throughout the year. During the blockage, Company pursued active dialogue with the local community and authorities for a peaceful resolution to this situation. Nexa remains committed to complying with all existing agreements, pursuing an active dialogue with the communities and authorities, and the social development of all its host communities.
The Atacocha mine has a treatment plant capacity of 4,500 tonnes of ore per day. The table below summarizes the Atacocha mine’s concentrate production, metal contained in concentrates produced and average grades for the periods indicated. Production in 2024 was higher than in 2023 due to mining activities in higher-grade zones and improved plant efficiency.
Mining Operations
| For the Year Ended December 31, | |||
|---|---|---|---|
| 2024 | 2023 | 2022 | |
| Treatment ore (in tonnes) | 1,511,875 | 1,397,192 | 1,353,681 |
| Average ore grade | |||
| Zinc (%) | 0.90 | 0.77 | 0.89 |
| Lead (%) | 0.95 | 0.93 | 0.97 |
| Silver (ounces per tonne) | 1.03 | 1.21 | 1.05 |
| Gold (ounces per tonne) | 0.011 | 0.010 | 0.015 |
| Metal contained in concentrate production | |||
| Zinc (in tonnes) | 10,404 | 8,193 | 9,552 |
| Lead (in tonnes) | 12,295 | 11,116 | 11,204 |
| Silver (in oz) | 1,212,952 | 1,399,681 | 1,155,002 |
| Gold (in oz) | 9,113 | 7,559 | 13,593 |
| Cash cost, net of by-product credits (in US$/t) | (1,431.2) | (959.7) | (1,566.2) |
| Cash cost, net of by-product credits (in US$/lb) | (0.65) | (0.44) | (0.71) |
| Non-Expansion Capital Expenditures (in millions of US$) | 11.2 | 16.2 | 4.5 |
Mineral Reserves and Mineral Resources (Atacocha Underground)
The Atacocha Underground Mineral Reserves estimates are based on the definitions for Mineral Reserves in SK-1300 and the tables below are based on costs and modifying factors from the Atacocha Underground mine.
Atacocha Underground – Year End Mineral Reserves as of December 31, 2024 (on an 81.78% Nexa attributable ownership basis)(1)
| Grade · Contained Metal | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Class | Tonnage (2) | Zinc | Copper | Silver | Lead | Gold | Zinc | Copper | Silver | Lead | Gold |
| (Mt) | (%) | (%) | (g/t) | (%) | (g/t) | (kt) | (kt) | (koz) | (kt) | (koz) | |
| Proven | 1.46 | 3.94 | 0.33 | 86.2 | 1.56 | - | 57.7 | 4.8 | 4,053 | 22.8 | - |
| Probable | 3.34 | 4.54 | 0.43 | 76.6 | 1.27 | - | 151.4 | 14.2 | 8,216 | 42.4 | - |
| Total | 4.80 | 4.36 | 0.40 | 79.5 | 1.36 | - | 209.1 | 19.0 | 12,269 | 65.2 | - |
| 1. | Subpart 1300 of Regulation S-K definitions were followed for Mineral Reserves, which also are consistent with the CIM (2014) definitions. |
| 2. | Mineral Reserves data presented in this table are reported on 81.78% Nexa attributable ownership. |
| 3. | The Qualified Person for the Mineral Reserves estimate is Renzo Suarez, B.Eng., MAusIMM, a Nexa employee. |
| 4. | Numbers may not add due to rounding. |
| 5. | The point of reference for Mineral Reserves in this table is mill feed materials. |
Atacocha Underground – Year End Mineral Reserves as of December 31, 2024 (on a 100% ownership basis)(1)
| Grade · Contained Metal | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Class | Tonnage (2) | Zinc | Copper | Silver | Lead | Gold | Zinc | Copper | Silver | Lead | Gold |
| (Mt) | (%) | (%) | (g/t) | (%) | (g/t) | (kt) | (kt) | (koz) | (kt) | (koz) | |
| Proven | 1.79 | 3.94 | 0.33 | 86.2 | 1.56 | - | 70.5 | 5.9 | 4,956 | 27.8 | - |
| Probable | 4.08 | 4.54 | 0.43 | 76.6 | 1.27 | - | 185.1 | 17.4 | 10,047 | 51.9 | - |
| Total | 5.87 | 4.36 | 0.40 | 79.5 | 1.36 | - | 255.6 | 23.3 | 15,003 | 79.7 | - |
| 1. | Subpart 1300 of Regulation S-K definitions were followed for Mineral Reserves, which also are consistent with the CIM (2014) definitions. |
| 2. | Mineral Reserves data presented in this table represents 100% of the Mineral Reserves estimates for the property. Nexa owns 81.78%. |
| 3. | The Qualified Person for the Mineral Reserves estimate is Renzo Suarez, B.Eng., MAusIMM, a Nexa employee. |
| 4. | Numbers may not add due to rounding. |
| 5. | The point of reference for Mineral Reserves in this table is mill feed materials. |
Mining Operations
The Atacocha Underground Mineral Reserves estimates in the table above were prepared using DSO software, mine design and scheduling software. Mining methods used are C&F mining, using unconsolidated rock fill and hydraulic backfill, and SLS using unconsolidated rock fill. NSR values were calculated using mineral reserve metal prices, metallurgical recovery and consideration of smelter terms, including revenue from payable metals, price participation, penalties, smelter losses, transportation, treatment, refining and sales charges. A minimum mining width of 5.0m for C&F mining and 4.0 m for SLS mining were used for reserves shapes and development design and are reported inclusive of extraction losses and dilution. The Mineral Reserves were estimated at a NSR cut-off of US$73.54/t for SLS areas, and US$75.61/t for C&F areas depending on the zone. A number of incremental material (with values between US$49.67/t and US$73.54/t for SLS and values between US$51.73/t and US$75.61/t for C&F mining) was included in the estimate. Mineral Reserves estimates are based on average long-term metal prices of zinc: US$2,864.90/t (US$1.30/lb); copper: US$9,095.61/t (US$4.13/lb); lead: US$2,097.45/t (US$0.95/lb); and silver: US$24.83/oz. Metallurgical recoveries are accounted for in NSR calculations based on historical processing data and are variable as a function of head grade. Recoveries at LOM average head grades are 89.30% for Zn, 15.73% for Cu, 80.02% for Pb, and 62.92% for Ag. The current LOM production plan begins in 2028 and continues to 2034.
Atacocha Underground – Net Difference in Mineral Reserves between December 31, 2024 (on an 81.78% Nexa attributable ownership basis), versus December 31, 2023 (on a 75.96% Nexa attributable ownership basis)
| Contained Metal | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Class · Tonnage · Zinc · Copper · Silver · Lead · Gold | ||||||||||||
| (Mt)% · (kt)% · (kt)% · (koz)% · (kt)% · (koz)% | ||||||||||||
| Proven | 0.17 | 12.9 | 7.7 | 15.5 | 0.5 | 10.7 | 518 | 14.7 | 4.1 | 21.7 | - | - |
| Probable | 0.33 | 11.0 | 14.8 | 10.8 | 1.4 | 10.9 | 707 | 9.4 | 3.7 | 9.4 | - | - |
| Total | 0.50 | 11.6 | 22.5 | 12.1 | 1.9 | 10.8 | 1,225 | 11.1 | 7.7 | 13.4 | - | - |
Atacocha Underground – Net Difference in Mineral Reserves between December 31, 2024, versus December 31, 2023 (on a 100% ownership basis)
| Contained Metal | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Class · Tonnage · Zinc · Copper · Silver · Lead · Gold | ||||||||||||
| (Mt)% · (kt)% · (kt)% · (koz)% · (kt)% · (koz)% | ||||||||||||
| Proven | 0.08 | 4.9 | 4.8 | 7.3 | 0.2 | 2.8 | 303 | 6.5 | 3.2 | 13.0 | - | - |
| Probable | 0.12 | 3.1 | 5.3 | 2.9 | 0.5 | 3.0 | 160 | 1.6 | 0.8 | 1.6 | - | - |
| Total | 0.20 | 3.6 | 10.1 | 4.1 | 0.7 | 3.0 | 463 | 3.2 | 4.0 | 5.3 | - | - |
In comparison to 2023, Atacocha’s Underground Mineral Reserves increased by 3.6% and by 4.1% in zinc content (kt), mainly due to higher metal prices.
Mining Operations
Atacocha Underground – Year End Mineral Resources as of December 31, 2024 (on an 81.78% Nexa Attributable ownership basis)(1)
| Grade · Contained Metal | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Class | Tonnage (2) | Zinc | Copper | Silver | Lead | Gold | Zinc | Copper | Silver | Lead | Gold |
| (Mt) | (%) | (%) | (g/t) | (%) | (g/t) | (kt) | (kt) | (koz) | (kt) | (koz) | |
| Measured | 0.92 | 3.34 | 0.27 | 55.4 | 0.98 | - | 30.6 | 2.5 | 1,631 | 8.9 | - |
| Indicated | 2.12 | 3.18 | 0.37 | 55.3 | 0.92 | - | 67.5 | 7.9 | 3,777 | 19.6 | - |
| Total | 3.04 | 3.23 | 0.34 | 55.3 | 0.94 | - | 98.1 | 10.4 | 5,408 | 28.5 | - |
| Inferred | 6.76 | 4.02 | 0.55 | 76.6 | 1.20 | - | 271.7 | 37.2 | 16,655 | 80.9 | - |
| 1. | Subpart 1300 of Regulation S-K definitions were followed for Mineral Resources, which also are consistent with the CIM (2014) definitions. |
| 2. | Mineral Resources Tonnes and Contained Metal presented in this table are reported on 81.78% Nexa attributable ownership. |
| 3. | Mineral Resources are reported exclusive of those Mineral Resources that were converted to Mineral Reserves, and Mineral Resources are not Mineral Reserves and do not have demonstrated economic viability. |
| 4. | The Qualified Person for the Mineral Resources estimate is Jerry Huaman Abalos, B.Geo., MAusIMM CP(Geo), a Nexa employee. |
| 5. | Numbers may not add due to rounding. |
| 6. | The point of reference for Mineral Resources in this table is mill feed materials. |
Atacocha Underground – Year End Mineral Resources as of December 31, 2024 (on a 100% ownership basis)(1)
| Grade · Contained Metal | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Class | Tonnage (2) | Zinc | Copper | Silver | Lead | Gold | Zinc | Copper | Silver | Lead | Gold |
| (Mt) | (%) | (%) | (g/t) | (%) | (g/t) | (kt) | (kt) | (koz) | (kt) | (koz) | |
| Measured | 1.12 | 3.34 | 0.27 | 55.4 | 0.98 | - | 37.4 | 3.0 | 1,995 | 10.9 | - |
| Indicated | 2.60 | 3.18 | 0.37 | 55.3 | 0.92 | - | 82.6 | 9.6 | 4,618 | 24.0 | - |
| Total | 3.72 | 3.23 | 0.34 | 55.3 | 0.94 | - | 120.0 | 12.7 | 6,613 | 34.9 | - |
| Inferred | 8.26 | 4.02 | 0.55 | 76.6 | 1.20 | - | 332.2 | 45.5 | 20,366 | 98.9 | - |
| 1. | Subpart 1300 of Regulation S-K definitions were followed for Mineral Resources, which also are consistent with the CIM (2014) definitions. |
| 2. | Mineral Resources data presented in this table represents 100% of the Mineral Resources estimates for the property. Nexa owns 81.78%. |
| 3. | Mineral Resources are reported exclusive of those Mineral Resources that were converted to Mineral Reserves, and Mineral Resources are not Mineral Reserves and do not have demonstrated economic viability. |
| 4. | The Qualified Person for the Mineral Resources estimate is Jerry Huaman Abalos, B.Geo., MAusIMM CP(Geo), a Nexa employee. |
| 5. | Numbers may not add due to rounding. |
| 6. | The point of reference for Mineral Resources in this table is mill feed materials. |
The Atacocha Underground Mineral Resources estimates in the table above were completed using Datamine and Leapfrog software. Wireframes for geology and mineralization were constructed in Leapfrog based on geology sections, assay results, lithological information, underground mapping and structural data. Assays were capped to various levels based on exploratory data analysis and then composited to 2.0 m lengths. Wireframes were filled with blocks and sub-celling at wireframe boundaries. Blocks were interpolated with grade using the OK and ID 3 interpolation algorithms. Block estimates were validated using industry standard validation techniques. Classification of blocks used distance-based and mineralization continuity criteria. Mineral Resources are reported using all the material within resource shapes generated in DSO software, satisfying minimum mining width of 4.0 m in areas with C&F stopes shapes and 3.0 m for SLS stopes. The Mineral Resources are estimated at a NSR cut-off grade values of US$73.54/t for SLS areas and US$75.61/t for C&F areas depending on the zone. Mineral Resources estimates are based on average long-term metal prices of zinc: US$3,294.64/t (US$1.49/lb); copper: US$10,459.95/t (US$4.74/lb); lead: US$2,412.07/t (US$1.09/lb); and silver: US$28.55/oz. Metallurgical recoveries are accounted for in NSR calculations based on historical processing data and are variable as a function of head grade. Recoveries at LOM average head grades are 89.30% for Zn, 15.73% for Cu, 80.02% for Pb, and 62.92% for Ag.
Mining Operations
Atacocha Underground – Net Difference in Mineral Resources between December 31, 2024 (on an 81.78% Nexa attributable ownership basis), versus December 31, 2023 (on a 75.96% Nexa attributable ownership basis)
| Contained Metal | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Class · Tonnage · Zinc · Copper · Silver · Lead · Gold | ||||||||||||
| (Mt)% · (kt)% · (kt)% · (koz)% · (kt)% · (koz)% | ||||||||||||
| Measured | 0.12 | 14.8 | 2.9 | 10.6 | 0.4 | 17.0 | 221 | 15.6 | 1.1 | 14.3 | - | - |
| Indicated | 0.21 | 11.0 | 4.3 | 6.9 | 1.0 | 14.0 | 398 | 11.8 | 2.0 | 11.2 | - | - |
| Total | 0.33 | 12.1 | 7.3 | 8.0 | 1.3 | 14.7 | 618 | 12.9 | 3.1 | 12.2 | - | - |
| Inferred | 0.64 | 10.4 | 21.2 | 8.5 | 2.9 | 8.6 | 1,439 | 9.5 | 6.8 | 9.2 | - | - |
Atacocha Underground – Net Difference in Mineral Resources between December 31, 2024, versus December 31, 2023 (on a 100% ownership basis)
| Contained Metal | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Class · Tonnage · Zinc · Copper · Silver · Lead · Gold | ||||||||||||
| (Mt)% · (kt)% · (kt)% · (koz)% · (kt)% · (koz)% | ||||||||||||
| Measured | 0.07 | 6.6 | 1.0 | 2.7 | 0.2 | 8.7 | 138 | 7.4 | 0.6 | 6.1 | - | - |
| Indicated | 0.08 | 3.1 | (0.6) | (0.7) | 0.5 | 5.9 | 170 | 3.8 | 0.8 | 3.3 | - | - |
| Total | 0.15 | 4.1 | 0.4 | 0.3 | 0.8 | 6.6 | 308 | 4.9 | 1.4 | 4.2 | - | - |
| Inferred | 0.20 | 2.5 | 2.5 | 0.8 | 0.4 | 0.9 | 335 | 1.7 | 1.4 | 1.4 | - | - |
In comparison to 2023, Atacocha’s Underground Inferred Mineral Resources increased by 2.5% in mass and by 0.8% in zinc content (kt), mainly due to higher metal prices in 2024. In comparison to 2023, Atacocha’s Underground Measured and Indicated Mineral Resources increased by 4.1% in mass and by 0.3% in zinc content (kt), mainly due to higher metal prices in 2024.
For additional information, see the Technical Report Summary on the Cerro Pasco Complex Integration, filed as Exhibit 15.2 to Nexa’s annual report on Form 20-F for the year-ended December 31, 2023, as filed on March 27, 2024.
Mineral Reserves and Mineral Resources (Atacocha Open Pit)
The Atacocha Open Pit Mineral Reserves estimates are based on the definitions for Mineral Reserves in SK-1300 and the tables below are based on costs and modifying factors from the Atacocha Open Pit mine.
Atacocha Open Pit – Year End Mineral Reserves as of December 31, 2024 (on an 81.78% Nexa attributable ownership basis)(1)
| Grade · Contained Metal | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Class | Tonnage (2) | Zinc | Copper | Silver | Lead | Gold | Zinc | Copper | Silver | Lead | Gold |
| (Mt) | (%) | (%) | (g/t) | (%) | (g/t) | (kt) | (kt) | (koz) | (kt) | (koz) | |
| Proven | 1.18 | 1.08 | - | 38.9 | 1.17 | 0.18 | 12.7 | - | 1,469 | 13.7 | 6.7 |
| Probable | 1.81 | 0.97 | - | 33.3 | 1.15 | 0.22 | 17.6 | - | 1,943 | 20.9 | 13.0 |
| Total | 2.99 | 1.01 | - | 35.5 | 1.16 | 0.21 | 30.3 | - | 3,413 | 34.7 | 19.7 |
| 1. | Subpart 1300 of Regulation S-K definitions were followed for Mineral Reserves, which also are consistent with the CIM (2014) definitions. |
| 2. | Mineral Reserves data presented in this table are reported on 81.78% Nexa attributable ownership. |
| 3. | The Qualified Person for the Mineral Reserves estimate is Renzo Suarez, B.Eng., MAusIMM, a Nexa employee. |
| 4. | Numbers may not add due to rounding. |
| 5. | The point of reference for Mineral Reserves in this table is mill feed materials. |
Mining Operations
Atacocha Open Pit – Year End Mineral Reserves as of December 31, 2024 (on a 100% ownership basis)(1)
| Grade · Contained Metal | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Class | Tonnage (2) | Zinc | Copper | Silver | Lead | Gold | Zinc | Copper | Silver | Lead | Gold |
| (Mt) | (%) | (%) | (g/t) | (%) | (g/t) | (kt) | (kt) | (koz) | (kt) | (koz) | |
| Proven | 1.44 | 1.08 | - | 38.9 | 1.17 | 0.18 | 15.5 | - | 1,797 | 16.8 | 8.2 |
| Probable | 2.22 | 0.97 | - | 33.3 | 1.15 | 0.22 | 21.5 | - | 2,376 | 25.6 | 15.9 |
| Total | 3.66 | 1.01 | - | 35.5 | 1.16 | 0.21 | 37.0 | - | 4,173 | 42.4 | 24.1 |
| 1. | Subpart 1300 of Regulation S-K definitions were followed for Mineral Reserves, which also are consistent with the CIM (2014) definitions. |
| 2. | Mineral Reserves data presented in this table represents 100% of the Mineral Reserves estimates for the property. Nexa owns 81.78%. |
| 3. | The Qualified Person for the Mineral Reserves estimate is Renzo Suarez, B.Eng., MAusIMM, a Nexa employee. |
| 4. | Numbers may not add due to rounding. |
| 5. | The point of reference for Mineral Reserves in this table is mill feed materials. |
The Atacocha Open Pit Mineral Reserves estimates in the table above were prepared using DSO software, mine design and scheduling software. NSR values were calculated using mineral reserve metal prices, metallurgical recovery and consideration of smelter terms, including revenue from payable metals, price participation, penalties, smelter losses, transportation, treatment, refining and sales charges. The Mineral Reserves were estimated at a NSR cut-off values of US$20.42/t. A number of incremental material (with values between US$15.12/t and US$20.42/t was included in the estimates. Mineral Reserves estimates are based on average long-term metal prices of zinc: US$2,864.90/t (US$1.30/lb); lead: US$2,097.45/t (US$0.95/lb); and silver: US$24.83/oz; and gold: US$1,946.05/oz. Metallurgical recoveries are accounted for in NSR calculations based on historical processing data and are variable as a function of head grade. Recoveries at LOM average head grade are 70.44% for Zn, 83.98% for Pb, 75.76% for Ag, and 65.46% for gold. The current LOM plan continues to 2027.
Atacocha Open Pit – Net Difference in Mineral Reserves between December 31, 2024 (on an 81.78% Nexa attributable ownership basis) versus December 31, 2023 (on a 75.96% Nexa attributable ownership basis)
| Contained Metal | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Class · Tonnage · Zinc · Copper · Silver · Lead · Gold | ||||||||||||
| (Mt)% · (kt)% · (kt)% · (koz)% · (kt)% · (koz)% | ||||||||||||
| Proven | (0.27) | (18.9) | (2.2) | (14.7) | - | - | (310) | (17.4) | (3.1) | (18.5) | (4.8) | (41.7) |
| Probable | (0.06) | (3.3) | (0.6) | (3.5) | - | - | (14) | (0.7) | (0.4) | (2.0) | (4.4) | (25.3) |
| Total | (0.34) | (10.1) | (2.8) | (8.5) | - | - | (324) | (8.7) | (3.5) | (9.3) | (9.2) | (31.8) |
Atacocha Open Pit – Net Difference in Mineral Reserves between December 31, 2024, versus December 31, 2023 (on a 100% ownership basis)
| Contained Metal | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Class · Tonnage · Zinc · Copper · Silver · Lead · Gold | ||||||||||||
| (Mt)% · (kt)% · (kt)% · (koz)% · (kt)% · (koz)% | ||||||||||||
| Proven | (0.47) | (24.7) | (4.1) | (20.8) | - | - | (545) | (23.3) | (5.4) | (24.3) | (7.0) | (45.8) |
| Probable | (0.25) | (10.2) | (2.5) | (10.4) | - | - | (201) | (7.8) | (2.5) | (9.0) | (7.0) | (30.6) |
| Total | (0.72) | (16.5) | (6.5) | (15.0) | - | - | (746) | (15.2) | (7.9) | (15.7) | (14.0) | (36.7) |
In comparison to 2023, Atacocha’s Open Pit Mineral Reserves decreased by 16.5% in mass and by 15.0% in zinc content (kt), mainly due to the yearly depletion of reserves not fully compensated by additional drilling.
Mining Operations
Atacocha Open Pit – Year End Mineral Resources as of December 31, 2024 (on an 81.78% Nexa Attributable ownership basis)(1)
| Grade · Contained Metal | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Class | Tonnage (2) | Zinc | Copper | Silver | Lead | Gold | Zinc | Copper | Silver | Lead | Gold |
| (Mt) | (%) | (%) | (g/t) | (%) | (g/t) | (kt) | (kt) | (koz) | (kt) | (koz) | |
| Measured | 1.61 | 1.21 | - | 29.4 | 0.82 | 0.18 | 19.4 | - | 1,521 | 13.3 | 9.1 |
| Indicated | 3.50 | 0.99 | - | 28.4 | 0.87 | 0.23 | 34.7 | - | 3,204 | 30.4 | 25.8 |
| Total | 5.11 | 1.06 | - | 28.8 | 0.85 | 0.21 | 54.1 | - | 4,726 | 43.6 | 34.9 |
| Inferred | 1.51 | 1.33 | - | 31.3 | 1.11 | 0.20 | 20.0 | - | 1,514 | 16.8 | 9.8 |
| 1. | Subpart 1300 of Regulation S-K definitions were followed for Mineral Resources, which also are consistent with the CIM (2014) definitions. |
| 2. | Mineral Resources Tonnes and Contained Metal presented in this table are reported on 81.78% Nexa attributable ownership. |
| 3. | Mineral Resources are reported exclusive of those Mineral Resources that were converted to Mineral Reserves, and Mineral Resources are not Mineral Reserves and do not have demonstrated economic viability. |
| 4. | The Qualified Person for the Mineral Resources estimate is Jerry Huaman Abalos, B.Geo., MAusIMM CP(Geo), a Nexa employee. |
| 5. | Numbers may not add due to rounding. |
| 6. | The point of reference for Mineral Resources in this table is mill feed materials. |
Atacocha Open Pit – Year End Mineral Resources as of December 31, 2024 (on a 100% ownership basis)(1)
| Grade · Contained Metal | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Class | Tonnage (2) | Zinc | Copper | Silver | Lead | Gold | Zinc | Copper | Silver | Lead | Gold |
| (Mt) | (%) | (%) | (g/t) | (%) | (g/t) | (kt) | (kt) | (koz) | (kt) | (koz) | |
| Measured | 1.96 | 1.21 | - | 29.5 | 0.82 | 0.18 | 23.7 | - | 1,860 | 16.2 | 11.1 |
| Indicated | 4.29 | 0.99 | - | 28.4 | 0.87 | 0.23 | 42.5 | - | 3,918 | 37.1 | 31.5 |
| Total | 6.25 | 1.06 | - | 28.8 | 0.85 | 0.21 | 66.2 | - | 5,778 | 53.4 | 42.6 |
| Inferred | 1.84 | 1.33 | - | 31.3 | 1.11 | 0.20 | 24.4 | - | 1,851 | 20.5 | 11.9 |
| 1. | Subpart 1300 of Regulation S-K definitions were followed for Mineral Resources, which also are consistent with the CIM (2014) definitions. |
| 2. | Mineral Resources data presented in this table represents 100% of the Mineral Resources estimates for the property. Nexa owns 81.78%. |
| 3. | Mineral Resources are reported exclusive of those Mineral Resources that were converted to Mineral Reserves, and Mineral Resources are not Mineral Reserves and do not have demonstrated economic viability. |
| 4. | The Qualified Person for the Mineral Resources estimate is Jerry Huaman Abalos, B.Geo., MAusIMM CP(Geo), a Nexa employee. |
| 5. | Numbers may not add due to rounding. |
| 6. | The point of reference for Mineral Resources in this table is mill feed materials. |
The Atacocha Open Pit Mineral Resources estimates in the table above were completed using Datamine and Leapfrog software. Wireframes for geology and mineralization were constructed in Leapfrog based on geology sections, assay results, lithological information, underground and open pit mapping and structural data. Assays were capped to various levels based on exploratory data analysis and then composited to 2.0 m lengths. Wireframes were filled with blocks and sub-celling at wireframe boundaries. Blocks were interpolated with grade using the OK and ID 3 interpolation algorithms. Block estimates were validated using industry standard validation techniques. Classification of blocks used distance-based and mineralization continuity criteria. Mineral Resources are reported within resources open pit shell. The Mineral Resources are estimated at a NSR cut-off grade values of US$20.42/t. Mineral Resources estimates are based on average long-term metal prices of zinc: US$3,294.64/t (US$1.49/lb); lead: US$2,412.07/t (US$1.09/lb); gold: US$2,237.96/oz and silver: US$28.55/oz. Metallurgical recoveries are accounted for in NSR calculations based on historical processing data and are variable as a function of head grade. Recoveries at LOM average head grades are 70.44% for Zn, 83.98% for Pb, 75.76% for Ag, and 65.46% for Au.
Mining Operations
Atacocha Open Pit – Net Difference in Mineral Resources between December 31, 2024 (on an 81.78% Nexa attributable ownership basis), versus December 31, 2023 (on a 75.96% Nexa attributable ownership basis)
| Contained Metal | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Class · Tonnage · Zinc · Copper · Silver · Lead · Gold | ||||||||||||
| (Mt)% · (kt)% · (kt)% · (koz)% · (kt)% · (koz)% | ||||||||||||
| Measured | 0.24 | 17.5 | 1.9 | 11.1 | - | - | 140 | 10.2 | 1.3 | 11.2 | 0.74 | 8.9 |
| Indicated | 0.56 | 18.9 | 3.8 | 12.4 | - | - | 457 | 16.7 | 3.9 | 14.6 | 3.1 | 13.5 |
| Total | 0.80 | 18.5 | 5.8 | 11.9 | - | - | 598 | 14.5 | 5.2 | 13.5 | 3.8 | 12.2 |
| Inferred | 0.21 | 16.6 | 3.6 | 21.7 | - | - | 156 | 11.5 | 1.9 | 12.8 | 0.7 | 7.1 |
Atacocha Open Pit – Net Difference in Mineral Resources between December 31, 2024, versus December 31, 2023 (on a 100% ownership basis)
| Contained Metal | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Class · Tonnage · Zinc · Copper · Silver · Lead · Gold | ||||||||||||
| (Mt)% · (kt)% · (kt)% · (koz)% · (kt)% · (koz)% | ||||||||||||
| Measured | 0.16 | 9.2 | 0.7 | 3.2 | - | - | 42 | 2.3 | 0.5 | 3.3 | 0.1 | 1.1 |
| Indicated | 0.41 | 10.4 | 1.8 | 4.4 | - | - | 302 | 8.4 | 2.2 | 6.4 | 1.6 | 5.4 |
| Total | 0.57 | 10.0 | 2.5 | 3.9 | - | - | 344 | 6.3 | 2.8 | 5.4 | 1.7 | 4.2 |
| Inferred | 0.14 | 8.3 | 2.8 | 13.0 | - | - | 64 | 3.6 | 0.9 | 4.7 | (0.1) | (0.5) |
In comparison to 2023, Atacocha’s Open Pit Inferred Mineral Resources increased by 8.3% in mass and by 13.0% in zinc content (kt), mainly due to higher metal prices. In comparison to 2023, Atacocha’s Open Pit Measured and Indicated Mineral Resources increased by 10.0% in mass and by 3.9% in zinc content (kt), mainly due to higher metal prices.
For additional information, see the Technical Report Summary on the Cerro Pasco Complex Integration, filed as Exhibit 15.2 to Nexa’s annual report on Form 20-F for the year-ended December 31, 2023, as filed on March 27, 2024.
Aripuanã
The Aripuanã mine is located in the northwest corner of the Mato Grosso State in western Brazil, approximately 2,529 km by railroad and road to the Três Marias smelter, 2,831 km to the Juiz de Fora smelter or 2,660 km to the port of Santos. The approximate coordinates of the mine are 226,000m E and 8,888,000m N UTM 21L zone (South American 1969 datum) and the mine is located at an average elevation of 250 meters above sea level. The mine is accessible from the town of Aripuanã via a 25 km unpaved road, which is well maintained in the dry season. Aripuanã can be accessed from the state capital, Cuiabá, via a 16-hour drive (935 km) on paved and unpaved roads. The final 250 km between Cuiabá and Aripuanã are on unpaved roads.
The town of Aripuanã is also serviced by a paved airstrip suitable for light aircraft. There are no commercial flights travelling between Cuiabá and the town of Aripuanã. However, the site can be accessed via a three-hour chartered flight.
History
Aripuanã is an underground polymetallic mine containing zinc, lead and copper, located in the state of Mato Grosso, Brazil. In 2000, Dardanelos was created to represent a joint venture, or “contract of association,” between Karmin and Anglo American, with the intent of exploring the areas adjacent to the town of Aripuanã for base and precious metals. Anglo American and Karmin held 70% and 28.5% of Dardanelos, respectively, with the remaining interest (1.5%) owned by SGV Merchant Bank (“SGV”).
Mining Operations
In 2004, the initial agreement between Karmin and Anglo American was amended to include Nexa Brazil’s participation. Nexa Brazil subsequently acquired 100% of Anglo American’s interest in the project. In 2007, Karmin purchased SGV’s interests, raising its participation to 30%. In 2015, Nexa Peru acquired 7.7% of Nexa Brazil’s interests in Dardanelos. In 2019, Nexa Brazil became the owner of 100% of the Aripuanã mine.
In 2020, we reached an agreement with artisanal miners working adjacent to the property belonging to our Aripuanã mine, the ANM and the state government whereby Nexa assigned these artisanal miners an area to exercise their activities subject to certain conditions. The increase of artisanal mining activity or the failure of these artisanal miners to abide with our agreement may have an adverse effect on the development of our operations in Aripuanã.
In 2021, Nexa acquired two estates (584.9 hectares) located at the vicinity of the mine and concluded the process of documenting a third acquired in the past (100.0 hectares). The total land purchase of 684.9 hectares was required to meet the Rural Environmental Registration (CAR in Brazil) which requires areas of native vegetation that are not available within the area of enterprise.
In 2022, Nexa acquired six estates (1,332.4 hectares), located at the vicinity of the mine. The Rural Environmental Registry (CAR) was updated by Nexa and is in the process of being approved by the environmental agency, and, as of the date of this filing, we have not received a response from the environmental agency. On January 25, 2022, we signed an offtake agreement with a third-party international player (the “offtaker”), in which Nexa agreed to sell 100% of the copper concentrate produced by Aripuanã for a 5-year period starting in February 2023 and limited to 30,810 tonnes, at the lower of current market prices or a price cap. In September 2023, the parties agreed to amend the offtake agreement, which states that no penalty will be applied in case of delays in the agreed shipment schedule per year. However, if lower volumes are delivered in any year within the contract period, at the end of the contract period, the remaining balance will be shipped in a single additional delivery to total the 30,018 tonnes. The offtake agreement was structured to completely extinguish a previous existing future royalty obligation that Nexa had with the offtaker. Additionally, the Company opted to voluntarily and irrevocably designate the entire offtake agreement at fair value through profit and loss within the scope of IFRS Accounting Standards 9 rather than separate the value of the embedded derivative associated with the price cap, recognizing a non-cash accumulated loss of US$3.3 million in the income statement for the period ended on December 31, 2024. For further details on the offtake agreement, see Note 16(v) to our consolidated financial statements.
Ramp-up activities at the Aripuanã mine started in July 2022, and the mine continued production in the ramp-up phase for the duration of 2023 and into 2024. In June 2024, the Aripuanã mine concluded its ramp up phase and transitioned to an operational mine. We expect to reach nameplate capacity during the second half of 2025. For further information, see “Project implementation”, below.
Titles, leases and options
The mine holds one mining concession in the core area that has a total area of 3,639.9 hectares, two mining concession applications totaling 1,368.5 hectares, one right to apply for mining concession with 1,000.0 hectares and nine exploration authorizations totaling 35,152.7 hectares.
The Aripuanã mine holds surface rights sufficient to support the future operations. There is sufficient suitable land available within the mineral rights held by the Company for tailings disposal, mine waste disposal, and installations such as the process plant and related mine infrastructure.
The Aripuanã mine holds several permits and licenses supporting its current operations. The operating license renewal was submitted on time and is currently under review.
The Aripuanã region contains polymetallic VMS deposits with zinc, lead and copper, as well as small amounts of gold and silver, present in the form of massive mantles and veins, located in volcano sedimentary sequences belonging to the Roosevelt Group of Proterozoic age.
Mining Operations
Four main elongated mineralized zones have been defined in the central portion of the mine: (1) Arex, (2) Link, (3) Ambrex and (4) Babaçu. Limited exploration has identified possible additional mineralized bodies including Massaranduba, Boroca, and Mocotó to the south and Arpa to the north.
The Aripuanã polymetallic deposits are typical VMS deposits associated with felsic bimodal volcanism. The individual mineralized bodies have complex shapes due to intense tectonic activity. Stratabound mineralized bodies tend to follow the local folds, however, local-scale, tight isoclinal folds are frequently observed, usually with axes parallel to major reverse faults, causing rapid variations in the dips.
Massive, stratabound sulphide mineralization as well as vein and stockwork-type discordant mineralization have been described on the property. The stratabound bodies, consisting of disseminated to massive pyrite and pyrrhotite, with well-developed sphalerite and galena mineralization, are commonly associated with the contact between the middle volcanic and the upper sedimentary units. Discordant stringer bodies of pyrrhotite-pyrite-chalcopyrite mineralization are generally located in the underlying volcanic units or intersect the massive sulphide lenses and have been interpreted as representing feeder zones.
In 2024, Aripuanã’s strategy aimed to increase throughput rate and asset reliability, reduce plant downtime, improve metal recoveries, concentrate grades and quality while consuming our ore stockpile inventory, which was supported by infill drilling at Babaçu target to extend the Aripuanã LOM.
The Mineral Exploration brownfield program in 2024 was focused on identifying new mineralized zones in the Massaranduba target through exploratory drilling and the results confirmed the continuity of mineralization in the southeast extension of the Aripuanã trend.
In 2024, we spent a total of US$4.0 million on the Aripuanã brownfield program, including Aripuanã’s exploratory drilling program and infill drilling campaign. The total investment included drilling, geological activities, geochemistry, and more. In 2024, we drilled 6.5 km of diamond drilling in 9 drill holes, including Massaranduba exploratory drilling. For 2025, we expect to invest US$4.0 million in the brownfield exploration program to drill 10.0 km focusing on Massaranduba exploratory and conversion drilling.
Ramp-up activities
Ramp-up activities at the Aripuanã mine started in July 2022, and the mine continued in the ramp-up phase through 2023 and into 2024. In June 2024, the ramp-up phase was concluded and Aripuanã transitioned to an operational mine.
In the fourth quarter of 2024, we achieved an average of 67.0% of capacity utilization level, reflecting the impact of maintenance activities, tailings filter constraints, and heavy rainfall during the period, which was 20% higher than in 2023. We continue to focus on improving operational performance, with a particular focus on the tailings filter circuit. While capacity has significantly increased since production startup, challenges persist due to current constraints. To resolve this, we acquired a fourth tailings filter, which we expect to be delivered and installed during the second half of 2025, with commissioning expected for the first quarter of 2026. This upgrade will further enhance utilization capacity, ensuring optimal performance and in line with our commitment to operational excellence.
At the end of 2024, approximately 57.0kt of ore was stockpiled. Horizontal mine development reached an accumulated of 41.2 meters developed for both mines (Arex and Link). As of the date of this filing, the mine is fully operational, and underground activities are focused on developing and preparing new areas for mining operations.
As of December 31, 2024, 855 people were employed at Aripuanã. We also continued the qualification program for future mine and plant operating professionals, which had 95 candidates enrolled in 2024, of which 64.2% (61) obtained professional qualifications in the areas of maintenance and automation, and geology and surveying. The company hired 41.0% (25) of the attendees that obtained professional qualifications, of which 60.0% (15) are men and 40.0% (10) are women.
To date, cumulative incurred expansion capital expenditures on the mine total US$632.7 million, and we have not made any new expansion capital expenditures on the mine since 2022.
Mining Operations
The Aripuanã operation consists of two fully mechanized underground mines, the Arex Mine and Link Mine, which have been in operation since 2019. These mines use rubber-tired diesel equipment for development and production activities, with a production rate of approximately 2.3 Mtpy. Access to the mine is through one portal for Arex and one portal for Link. Production drilling operations have been carried out by company personnel using various drilling machines throughout the history of the Aripuanã mine. The Aripuanã processing plant has been in operation since 2022.
All infrastructure required for the current mining and processing operations has been constructed and is operational. This includes the underground mines, access roads, power lines, water pipelines, offices and warehouses, a processing plant/concentrator, conveyor systems, waste rock facilities, temporary ore stockpiles, paste-fill plants, and tailings storage facilities.
The Aripuanã mine is connected to the main grid at 230 kV, with energy measurement and billing conducted at SE Dardanelos, 20 km away, using a 69 kV line to the unit. Power distribution occurs at 13.8 kV, and the unit is equipped with a 25/31 MW transformer. Currently, the contracted power demand with Energisa S.A. is 23 MW during peak hours and 20.7 during off-peak hours. Additionally, there are five 750 kVA diesel generators in place.
In 2024, we spent US$38.6 million on sustaining capital expenditures for this property, primarily associated with mine development, equipment replacement, and other major infrastructure projects.
The Aripuanã mine was in ramp-up phase during fiscal years 2022, 2023 and the first half of 2024 and has a treatment plant with a nominal design processing capacity of approximately 6,300 tonnes of ore per day. The table below summarizes the Aripuanã mine’s concentrate production, metal contained in concentrates produced and average grades for the periods indicated. Production in 2024 was higher than in 2023 due to operational improvements and process adjustments throughout the year.
| For the Year Ended December 31, | |||
|---|---|---|---|
| 2024 · 2023 · 2022 | |||
| Treatment ore (in tonnes) | 1,475,566 | 1,311,430 | 100,114 |
| Average ore grade | |||
| Zinc (%) | 3.23 | 3.31 | 2.44 |
| Copper (%) | 0.56 | 0.68 | 0.49 |
| Lead (%) | 1.12 | 1.05 | 0.00 |
| Silver (ounces per tonne) | 1.17 | 0.96 | 0.61 |
| Gold (ounces per tonne) | 0.017 | 0.015 | 0.011 |
| Metal contained in concentrate production | |||
| Zinc (in tonnes) | 31,613 | 22,099 | 670 |
| Copper (in tonnes) | 5,519 | 4,443 | 195 |
| Lead (in tonnes) | 13,062 | 6,331 | 0 |
| Silver (in oz) | 1,101,313 | 513,916 | 20,497 |
| Gold (in oz) | 14,037 | 7,954 | 273 |
| Cash Cost, net of by-product credits (in US$/t) | - | - | - |
| Cash Cost, net of by-product credits (in US$/lb) | - | - | - |
| Non-Expansion Capital Expenditures (in millions of US$) | 42.7 | 60.1 | 68.4 |
The Aripuanã Mineral Reserves estimates are based on the definitions for Mineral Reserves in SK-1300 and the tables below are based on costs and modifying factors from the Aripuanã mine.
Mining Operations
Aripuanã – Year End Mineral Reserves as of December 31, 2024 (on a 100% ownership basis)(1)
| Grade · Contained Metal | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Class | Tonnage (2) | Zinc | Copper | Silver | Lead | Gold | Zinc | Copper | Silver | Lead | Gold |
| (Mt) | (%) | (%) | (g/t) | (%) | (g/t) | (kt) | (kt) | (koz) | (kt) | (koz) | |
| Proven | 5.86 | 3.79 | 0.20 | 33.1 | 1.37 | 0.24 | 222.0 | 11.9 | 6,230 | 80.3 | 44.7 |
| Probable | 26.82 | 4.69 | 0.11 | 42.6 | 1.81 | 0.19 | 1,258.2 | 29.7 | 36,719 | 485.3 | 163.7 |
| Total | 32.68 | 4.53 | 0.13 | 40.9 | 1.73 | 0.20 | 1,480.2 | 41.6 | 42,949 | 565.6 | 208.3 |
| 1. | Subpart 1300 of Regulation S-K definitions were followed for Mineral Reserves, which also are consistent with the CIM (2014) definitions. |
| 2. | Mineral Reserves data presented in this table represents 100% of the Mineral Reserves estimates for the property. Nexa owns 100% of property. |
| 3. | The Qualified Person for the Mineral Reserves estimate is Vitor Ferraz Viana, B.Eng., FAusIMM, a Nexa employee. |
| 4. | Numbers may not add due to rounding. |
| 5. | The point of reference for Mineral Reserves in this table is mill feed materials. |
The Aripuanã Mineral Reserves estimates are based on four main orebodies: Arex, Link and Ambrex and the two main types of mineralization in the deposit are stratabound and stringer. The main commodities produced are zinc, copper, lead, silver and gold. The dilution that has been applied is related to the selected mining method. The two main mining methods used at Aripuanã are longitudinal longhole retreat (“bench stoping”) and transverse longhole mining (vertical retreat mining, or “VRM”) with primary and secondary stope extraction. Dilution is applied on a percentage basis, with no grade applied to the diluting material. The NSR factors were determined using long-term metal price forecasts, metallurgical recoveries, transport, treatment, and refining costs. A break-even NSR cut-off value is US$60.68/t processed was estimated from forecasted operating costs and some incremental material between US$49.00/t and US$60.68/t was included. A minimum mining width of 4.0 m was used for bench stoping and 15.0 m for VRM. The long-term prices derived are in line with the consensus forecasts from banks and independent institutions. Mineral Reserves estimates are based on average long-term metal prices of zinc: US$2,864.90/t (US$1.30/lb); copper: US$9,095.61/t (US$4.13/lb); lead: US$2,097.45/t (US$0.95/lb); and silver: US$24.83/oz; and gold: US$1,946.05/oz. Recoveries at LOM average head grades are 91.08% for Zn, 84.92% for Pb, 60.00% for Cu, 68.00% for Ag, and 67.80% for Au. The current LOM plan continues to 2039.
Aripuanã – Net Difference in Mineral Reserves between December 31, 2024, versus December 31, 2023 (on a 100% ownership basis)
| Contained Metal | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Class · Tonnage · Zinc · Copper · Silver · Lead · Gold | ||||||||||||
| (Mt)% · (kt)% · (kt)% · (koz)% · (kt)% · (koz)% | ||||||||||||
| Proven | (0.57) | (8.8) | (24.2) | (9.8) | (1.9) | (13.9) | (763) | (10.9) | (9.6) | (10.7) | (12.5) | (21.8) |
| Probable | 2.18 | 8.8 | 153.1 | 13.9 | (2.1) | (6.7) | 3,110 | 9.3 | 58.0 | 13.6 | (3.6) | (2.1) |
| Total | 1.61 | 5.2 | 128.9 | 9.5 | (4.0) | (8.9) | 2,347 | 5.8 | 48.4 | 9.3 | (16.0) | (7.1) |
In comparison to 2023, Aripuanã’s Mineral Reserves increased by 5.2% in mass and increased by 9.5% in zinc content (kt), mainly due to the geological model reinterpretation in the Ambrex area and infill drilling at the Babaçu area. Mineral Reserve depletion during 2024 accounted for 1.6Mt containing 46.9kt of zinc.
Mining Operations
Aripuanã – Year End Mineral Resources as of December 31, 2024 (on a 100% ownership basis)(1)
| Grade · Contained Metal | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Class | Tonnage (2) | Zinc | Copper | Silver | Lead | Gold | Zinc | Copper | Silver | Lead | Gold |
| (Mt) | (%) | (%) | (g/t) | (%) | (g/t) | (kt) | (kt) | (koz) | (kt) | (koz) | |
| Measured | 0.49 | 2.16 | 0.39 | 18.6 | 0.71 | 0.50 | 10.6 | 1.9 | 293 | 3.5 | 7.9 |
| Indicated | 4.91 | 3.41 | 0.20 | 33.5 | 1.26 | 0.28 | 167.4 | 9.8 | 5,288 | 61.9 | 44.2 |
| Total | 5.40 | 3.30 | 0.22 | 32.1 | 1.21 | 0.30 | 178.0 | 11.7 | 5,581 | 65.4 | 52.1 |
| Inferred | 44.19 | 3.16 | 0.31 | 41.2 | 1.21 | 0.38 | 1,396.4 | 137.0 | 58,535 | 534.7 | 539.9 |
| 1. | Subpart 1300 of Regulation S-K definitions were followed for Mineral Resources, which also are consistent with the CIM (2014) definitions. |
| 2. | Mineral Resources data presented in this table represents 100% of the Mineral Resources estimates for the property. Nexa owns 100% of property. |
| 3. | Mineral Resources are reported exclusive of those Mineral Resources that were converted to Mineral Reserves, and Mineral Resources are not Mineral Reserves and do not have demonstrated economic viability. |
| 4. | The Qualified Person for the Mineral Resources estimate is José Antonio Lopes, B.Geo., FAusIMM(Geo), a Nexa employee. |
| 5. | Numbers may not add due to rounding. |
| 6. | The point of reference for Mineral Resources in this table is mill feed materials. |
The Mineral Resources estimates for the Aripuanã mine were completed for Babaçu, Arex, Ambrex and Link. The block models were created using Datamine and Leapfrog software. Wireframes for geology and mineralization were constructed in Leapfrog based on geology sections, assay results, lithological information and structural data. Assays were capped to various levels based on exploratory data analysis and then composited to one-meter lengths. Wireframes were filled with blocks measuring 5 meters by 5 meters by 5 meters with sub-celling at wireframe boundaries. Blocks were interpolated with grade using the OK and ID 3. Blocks estimates were validated using industry standard validation techniques. Classification of blocks was based on distance-based criteria. Potentially mineable shapes of underground mineral resources are generated using DSO software. The Mineral Resources of the Aripuanã mine are reported using a cut-off value of US$60.68/t. Mineral Resources estimates are based on average long-term metal prices of: zinc: US$3,294.64/t (US$1.49/lb); copper: US$10,459.95/t (US$4.74/lb); lead: US$2,412.07/t (US$1.09/lb); silver: US$28.55/oz and gold: US$2,237.96/oz. Metallurgical recoveries are accounted for in NSR calculations based on metallurgical test work and are variable as a function of head grade and ore type. Recoveries at the LOM average head grades material are 91.08% for Zn, 84.92% for Pb, 60.00% for Cu, 68.00% for Ag, and 67.80% for Au.
Aripuanã – Net Difference in Mineral Resources between December 31, 2024, versus December 31, 2023 (on a 100% ownership basis)
| Contained Metal | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Class · Tonnage · Zinc · Copper · Silver · Lead · Gold | ||||||||||||
| (Mt)% · (kt)% · (kt)% · (koz)% · (kt)% · (koz)% | ||||||||||||
| Measured | 0.14 | 40.0 | 1.5 | 16.5 | 0.5 | 35.7 | 33 | 12.7 | 0.5 | 16.7 | 3.8 | 92.7 |
| Indicated | (0.28) | (5.4) | (37.6) | (18.3) | 0.5 | 5.4 | (552) | (9.5) | (13.9) | (18.3) | (0.9) | (2.0) |
| Total | (0.14) | (2.5) | (36.1) | (16.9) | 1.0 | 9.3 | (519) | (8.5) | (13.4) | (17.0) | 2.9 | 5.9 |
| Inferred | 5.44 | 14.0 | 51.8 | 3.9 | 9.1 | 7.1 | 1,600 | 2.8 | (3.9) | (0.7) | 4.2 | 0.8 |
In comparison to 2023, Aripuanã’s Inferred Mineral Resources increased by 14.0% in mass and by 3.9% in zinc content (kt) in 2024, mainly due to the Ambrex mineralized zone model review, increased grade and geological continuity. In comparison to 2023, Aripuanã’s Measured and Indicated Mineral Resources decreased by 2.5% in mass and by 16.9% in zinc content (kt) in 2024, mainly due to the conversion to Mineral Reserves.
For additional information, see the “Technical Report Summary on Aripuanã”, filed as Exhibit 15.4 to our annual report on Form 20-F/A for the year-ended December 31, 2020, as filed on November 4, 2021.
Concentrate sales
All the metal produced by our mines is processed into concentrates. Our mining operations sell the concentrates that they produce to third parties and to our own smelters pursuant to arm’s length transactions. Each mine bears the cost of transporting the concentrate to the point of sale where the smelter or trader purchases the concentrate. The smelter or trader pays the mine for the percentage of metals contained in the concentrate, net of charges for treating the concentrate and refining the metals. The typical payable percentage is 85.0% for zinc contained in concentrate, 96.5% for copper contained in concentrate and 95.0% for lead contained in concentrate, minus treatment charges.
Mining Operations
Growth projects
In addition to Nexa’s operating mines and smelters, a component of our business focuses on growth and exploration, which are activities associated with ascertaining the existence, location, extent or quality of a mineral deposit. Our exploration activities encompass brownfield and greenfield projects. Brownfield projects are exploration or development projects near or within our existing operations, which can share infrastructure and management of our existing operations. Greenfield projects are exploration or development projects that are located outside the area of influence of our existing mine operations and/or infrastructure, which will be independently developed and managed from our existing operations.
Vazante mine deepening project and other Vazante initiatives
One of our main brownfield projects is the Vazante mine deepening project, which involves extending the mine life of Vazante. The capital expenditures related to this project in 2024 totaled US$0.4 million, and an additional US$1.8 million towards other expansion projects, focusing on the LOM extension. We expect to invest an additional US$0.3 million in 2025 for the deepening project and US$1.7 million for several other expansion projects at the Vazante mine. The Vazante mine deepening project began in 2013 and the completion of this project, which was expected to occur in 2024, was postponed due to our capital allocation strategy and the focus on other Vazante initiatives, which is now expected to be completed in 2028.
In addition, we are conducting exploration activities below the mine’s current operating level and alongside the orebody. As part of this project, we are investing in ongoing exploration activities and infrastructure, including expansion of an underground pumping station, an increase in the capacity of the ventilation system, emergency paths, access ramps, electrical networks and substations. In 2023, we prepared the area to receive such equipment in accordance with the project’s specifications and in 2024 we completed activities in accordance with the updated project schedule. In 2025, we expect to begin civil works and complete it in 2026. For 2027 and 2028, planned activities involve the execution of electromechanical work to complete mechanical operations.
Cerro Pasco Complex Integration Project
The Cerro Pasco Complex Integration Project is one of our main brownfield projects, which involves the continued integration of the El Porvenir and Atacocha underground mines. The Integration Project is intended to continue to capture synergies between the two mining operations, as a result of their proximity and operational similarities, with ore from both the underground mines being processed at the El Porvenir processing plant. The goal of the Integration Project is to achieve cost and investment savings, thereby reducing the environmental footprint and extending the combined LOM of the two mines. In the fourth quarter of 2024, our Board of Directors, through the Finance Committee approved the first phase of the project, the tailings pumping and piping system, following a recommendation from the SCP committee. For further information see “Information on the Company—Mining Operations—Cerro Pasco Complex—Integration Project.”
Bonsucesso
The Bonsucesso project is a greenfield underground mine project that was formerly part of the Morro Agudo complex (Ambrósia Trend). The Bonsucesso project was not included in the sale of the Morro Agudo complex. The project is located 8 km north of the Ambrósia Sul mine and approximately 60 km north of the Morro Agudo mine.
In 2024, we had no exploratory activities in the Bonsucesso project, and no activities are expected for 2025.
Mining Operations
The feasibility study was concluded in 2022 with no amount invested since. The total investments related to this project, as of December 31, 2024, totaled US$12.7 million, which includes all project studies (from the scoping study to the feasibility study) and incurred expenses related to construction and operating infrastructure.
The strategic review of our assets continues with initiatives to optimize our portfolio. We continue to assess risk-return alternatives, and we are currently revisiting the project, taking into consideration our capital allocation strategy and our focus on free cash flow generation.
Mining greenfield projects
| Project Name | Current Project Status |
|---|---|
| Magistral | Under Review |
| Hilarión | Exploration phase |
| Florida Canyon Zinc | Exploration phase |
We summarize below certain information, including the outlook, for each of our greenfield projects. As of the date of this annual report, none of our greenfield projects have Mineral Reserves under S-K 1300.
Magistral
The Magistral mining project is located in the Ancash region of Peru, approximately 450 km northeast of the capital of Lima and approximately 140 km east of the port city of Trujillo. The Magistral property can be reached by vehicle by driving a total of 272 km from Trujillo, much of which consists of poorly maintained roads that traverse steep topography. The Magistral Project consists of one large, irregularly shaped block of contiguous concessions and two smaller, non-contiguous single concessions. The Magistral Project comprises 36 granted concessions, totaling 16,416.0 hectares. The project is an open pit copper mine with molybdenum concentrate as a by-product. In 2016, ProInversión approved an initial feasibility study, which set forth production rates starting at 10 thousand tonnes per day and achieving 30 thousand tonnes per day. In 2016, the MINEM approved an environmental impact assessment (“EIA”), to process up to 30 ktpd. In 2023, we requested a modification of the EIA and in May 24, 2024, the National Service for Environmental Certification of Sustainable Investments (Servicio Nacional de Certificación Ambiental para las Inversiones Sostenibles, or “SENACE”) formally rejected the modification request of the EIA. We are currently addressing the situation with the relevant authorities, and we expect to reach a solution in 2025. The denial of the permit impacts our assessment of the project’s economic feasibility, technical development, as well as our impairment analysis. Additionally, because of the denial, in June 2024, the Magistral project was tested for impairment resulting in a loss of US$58 million.
Nexa Peru was awarded the contract to develop the Magistral mining project in 2011, which has been amended from time to time. Nexa made an initial payment of US$8.0 million to acquire the Magistral concessions, subject to a 2.0% NSR royalty upon production. Under the terms of the contract in 2016, Nexa Peru exercised the option by committing to invest a minimum 70% of declared initial capital expenditures by September 2024 and as a result of the COVID-19 pandemic, this term was extended by the government for an additional year, starting in September 2024. In 2023, new alignments were finalized, and an additional 35-month extension period was approved by force majeure, extending the period until August 2028. Pursuant to the terms of this commitment with the Peruvian Government to minimum investments levels in the project during this period, Nexa Peru would be required to pay a penalty of 30% of the unexecuted minimum investment commitment if not completed by August 2028. As of December 31, 2024, the unexecuted minimum investment commitment was US$323.0 million, and, if not completed, the penalty exposure would be US$97.0 million. Nexa Peru currently holds a 100.0% interest in 15 of the 36 concessions, Nexa holds 21 concessions by way of a lease agreement entered into with Companía Magistral S.A.C., a company also controlled by Nexa Peru. We spent approximately US$1.7 million on the Magistral project in 2024 and continue to review capital allocation to this project in our portfolio.
Exploration developments
The Magistral property is near the northeastern end of the Cordillera Blanca, a region that is underlain predominantly by Cretaceous carbonate and clastic sequences. These units strike north to northwest and are folded into a series of anticlines and synclines with northwest-trending axes.
Mining Operations
Since acquiring the Magistral project in 2011, Nexa has initiated a comprehensive exploration program consisting of geological mapping, prospecting and sampling, ground geophysical surveying, and diamond drilling. Geological mapping at a scale of 1:2,000 was completed in the Ancapata area and the area north-northeast of Magistral. The objective was to verify and supplement the information available from Ancash Cobre’s exploration.
From October 2012 to January 2014, Arce Geofisico SAC was contracted to complete ground magnetic and Induced Polarization (IP) surveying over an area of 520 hectares covering the Magistral deposit and the adjoining Ancapata area. The objective was to characterize the geophysical signature of the Magistral deposit and to survey the Ancapata area. Work was completed on 100 m spaced lines oriented at N125°W. An initial 30 line-km survey was expanded to 55.1 line-km of IP and 57.25 line-km of ground magnetics in order to delineate chargeability and resistivity anomalies.
Through the end of 2015, a total of approximately 101,900 m of surface diamond drilling has been completed in 486 drill holes. In addition, 14 short underground diamond holes were drilled for a total of 1,298.8 m in the San Ernesto, Arizona, and Sara zones between 1969 and 1973. In 1999, 2000, and 2001, Anaconda drilled 76 diamond drill holes totaling 24,640 m. All surface drilling from 2000 onward was carried out on northeast (035 o) and northwest (305 o) oriented sections. In 2004, Ancash Cobre (or Inca Pacific) completed 34 drill holes, totaling 7,985 m, and in 2005 Ancash Cobre (or Quadra) drilled 14,349 m in 60 holes. Milpo’s drilling in 2012 was contracted to Redrilsa Drilling S.A. (or Redrilsa). Since 2012, the drilling has been contracted to Geotecnia Peruana S.R. Ltda.
Of the 71 holes drilled in 2013, six were drilled to gain geotechnical information and the remainder were infill holes. Drilling in 2014 consisted of a combination of infill, geotechnical, and metallurgical holes. In 2015, drilling consisted entirely of infill holes, drilling ceased on the property in the same year. No exploration drilling program was carried out since then and no exploratory drilling program is scheduled for 2025.
Hilarión
The Hilarión project is located in the Ancash region of Peru, approximately 230 km north of Lima, the capital of Peru, and approximately 80 km south of the city of Huaraz and is accessible by paved road from Lima. It consists of 48 mineral concessions covering an area of approximately 9,374.0 hectares. Hilarión is a skarn mineral deposit made of vertical tabular ore bodies containing sulfide zinc, lead, silver and copper deposits. Hilarión and El Padrino and other occurrences in proximity to them (Mia, Eureka and others) constitute a large mineralized system, open in several directions for a potential increase in resources, extended mine life and increased production capacity in the future. The conceptual plan for the project includes the development of an underground mine that could either use its own processing plant or use one of the several existing plants in the area, such as Pachapaqui, Huanzala and Atalaya plants.
In 2020, we filed a preliminary economic assessment (“PEA”) for the Hilarión project. In 2021 and 2022, we drilled 28.5 km of diamond drilling to confirm and expand the mineralization in Hilarión Sur and west. In 2024, we spent approximately US$2.0 million on the Hilarión project, including mineral rights, project maintenance, geology review works and environmental obligations. We had no drilling activities at the project in 2024. In 2025, we have budgeted US$1.2 million for the Hilarión project maintenance, and we have planned no drilling activities.
Florida Canyon Zinc
The Florida Canyon Zinc project is located in the Eastern Cordillera of Peru at the sub-Andean front in the upper Amazon River Basin, 680 km north-northeast of Lima and 245 km northeast of Chiclayo and is accessible by paved road from Lima. It is comprised of 11 contiguous mining concessions, covering approximately 8,700.0 hectares, is owned by Minera Bongará S.A. and operated by Nexa Peru, a joint venture between Nexa Peru, Solitario Exploration and Royalty Corp. and Minera Solitario Peru S.A.C. (collectively, Solitario) in existence since 2006. As of December 31, 2024, Nexa Peru owns a 61.00% interest in this joint venture, which may increase up to 70.00% upon Nexa Peru’s satisfaction of certain conditions.
Although a pre-feasibility study relating to the Florida Canyon Zinc was released in 2017, the project continues to be treated as an advanced mineral exploration project.
Mining Operations
In 2022, we advanced the opening of the road that connects the project structures to the main camp and carried out geometallurgical tests to establish better mineralogical and metallurgical knowledge of the deposit, which showed high recovery of zinc and lead concentrates, as well as the presentation of the fifth environmental modification to the competent body.
In 2023, drilling at the Florida Canyon began in the third quarter due to a delay in the drilling program caused by lack of transportation for drilling materials. In September 2023, construction and maintenance of the motorized trail, which aims to reach La Florida Annex, commenced and was completed in 2024.
In 2024, we focused on maintenance of local infrastructure, such as opening access to receive future drilling campaigns.
We spent approximately US$2.0 million on this project in 2024, and we have budgeted US$1.5 million for the Florida Canyon project in 2025, including road maintenance, geological review and social programs. No drilling activities are planned for 2025.
Other Greenfield exploration projects
Project in Namibia
We have been developing exploratory work in Namibia since 2015, as part of a joint venture with the Japan, Oil, Gas and Metals National Corporation (“JOGMEC”), a Japanese state-owned company. The project was part of a farm-out process of the Namibian tenements inherited from the former strategy of Votorantim Metals to explore opportunities in Africa, where Nexa has a back-in right to invest and maintain participation depending on exploration results. The exploration area is located 360 km north of Windhoek. This early-stage exploratory program is targeting sediment-hosted copper mineralization, such as the Tsumeb and Kombat mines, both of which contain rocks from the Otavi Mountain land terrain.
Nexa currently holds 231,152.0 hectares across 12 exclusive prospective licenses (“EPL”) in the Tsumeb belt and 154,599.6 hectares across six EPLs for regional targets.
The 2022 exploration expenditures totaled US$3.1 million (US$2.2 million for JOGMEC expenditures and US$0.8 million for Nexa expenditures) with a total of 9.1 km drilled. The focus of the drilling campaign in 2022 was the expansion of mineralization in the Otavi target and the identification of new mineralized zones of the “Deblin” copper trend in the Namibia North target.
The drilling campaign in 2023 was focused on extending the known mineralization from the Deblin trend, intensifying drilling to further investigate polymetallic mineralization identified at the Ondjondjo target and targeting of high-grade copper sediment deposits along the fertile Tsumeb belt. We spent approximately US$2.2 million, divided between Nexa (US$0.3 million) and JOGMEC (US$1.8 million) on this project in 2023 to drill 4.9 km.
Drilling activities in 2024 were focused on the Tsumeb East target, located a few kilometers from the well-known Tsumeb Cu-Pb deposit in a similar geological setting. A total of 2.0 km of exploration drilling was completed in 2024. The completion of the AMT airborne survey, coupled with detailed geological mapping, has delineated high-priority anomalies at the Tsumeb East target. We also drilled these anomalies to define the geological endowment.
To date, we are defining the budget for the project as part of a joint venture with “JOGMEC”. Nexa is currently focusing on mapping and defining regional opportunities. In 2025, we plan to execute a geophysical survey to generate new targets to evolve into exploratory drilling in the coming years.
Mining Operations
Permits & authorizations for greenfield projects
The following table summarizes the status of the main permits and authorizations for our greenfield projects.
| Project | Status |
|---|---|
| Magistral | An amendment to the EIA was submitted to the SENACE in the fourth quarter of 2021 for its assessment. In October 2023, we responded to SENACE inquiries. The amendment to the EIA was rejected in 2024. All other permits are valid. |
| Hilarión | The most recent environmental study is the fifth modification to the Hilarión Project’s Environmental Impact Statement (“EIS”), which consisted of obtaining approval for new exploration platforms and reviewing the drilling program. The project’s EIS study is valid until 2027. The authorization for exploratory activities at the El Padrino deposit was extended until March 2025. Currently, the Ministry of Energy and Mines is evaluating the fourth modification to the EIS. A detailed EIS was approved in 2020, which is valid until 2025. The most recent environmental study for the Azulmina project is the modification of the EIS, which consisted of obtaining approval for new exploration platforms and revising the drilling program. The study is valid until 2028. |
| Florida Canyon Zinc | The most recent environmental study is the fifth modification to the Florida Canyon Project’s EIS, which consisted of obtaining approval for new exploration platforms and reviewing the drilling program. It was approved in 2023 and is valid until 2028. |
Tailings disposal
Regulatory framework
In Brazil, tailings dams’ failures have triggered the issuance of new regulations. On January 25, 2019, there was a tragic failure of a tailings dam in the city of Brumadinho, in the state of Minas Gerais, Brazil. The Brumadinho dam, that belongs to Vale S.A., was originally built using the upstream method. A report by a panel of technical experts commissioned by Vale S.A. found that the tailings dam failure was the result of flow liquefaction within the tailings in the dam. Another upstream-method tailings dam in Brazil, the Fundão tailings dam owned by Samarco Mineração S.A., failed in November 2015. Each of these failures released muddy tailings downstream, flooded certain communities, caused fatalities and resulted in extensive environmental damage to the surrounding area.
In response to failures of tailings dams in Brazil, the state of Minas Gerais enacted regulations in February 2019 affecting the use of dams in the state, including tailings dams and effluent dams that mandate the decommissioning of all upstream tailings dams and prohibit construction of new tailings dams using the upstream method. Additionally, a rule approved by the ANM requires all inactive upstream dams to be decommissioned by 2021 and active upstream dams to be decommissioned by 2023.
In addition, in February 2019, the state of Minas Gerais enacted regulations that prohibit the construction of a new dam or the expansion of existing dams if communities are established within its self-rescue zone, an area encompassing the portion of the valley downstream of the dam where timely evacuation and intervention by the competent authorities in emergency situations is not possible. All of the tailings dams located in Minas Gerais have permission to operate, however, future licensing for new tailings storage facilities or new raises must consider any community in the hazardous zone. Due to the difficulty in licensing new dams in the state of Minas Gerais, in February 2023 we began industrial-scale testing the technology developed for dry stacking disposal at the Três Marias unit, which consists of filtering the waste pulp for subsequent disposal through the dry stacking process, as waste disposal in this unit was going directly to its tailings deposits. In 2024, the initiative achieved excellent results successfully filtering residue and we continued to develop the project during the initial stages of the industrial-scale test, filtering an average of 92.4% of the operation’s material throughout the year. The remaining residue is disposed in the west 1 module of the Murici Deposit. We expect that the Company will be able to utilize dry disposal in the future to reduce the risks for communities in the hazardous zones. Due to these advancements, we began the licensing process for government approval of the dry stacking disposal facility at Três Marias.
Mining Operations
In 2020, the mining authorities in Brazil enacted two regulations that establish new procedures related to dams. The first resolution (Resolução ANM 32/2020), decreed in May 2020, determines procedures to develop dam break studies and deadlines to update the Emergency Action Plan (“EAP”) depending on the dam class. This regulation updated previous mining agency standards. We have updated the dam break studies of all mining dams according to these procedures. The second resolution (Resolução ANM 51/2020), decreed in December 2020, defines procedures to certify the EAP. In 2022 the ANM enacted Resolution No. 95/2022, amended by Resolution No. 130/2023, which consolidates all dam safety standards by unifying and regulating the innovations promoted by Law No. 14,006/2020.
At the end of 2020, the Brazilian Federal Authorities decreed that the new dam safety law (Law No. 14,006/2020) updates the previous dam safety Law No. 12,334 enacted in 2010. Similar to the regulation enacted in February 2019, this new law defines that new upstream tailings dams and new raises are no longer permitted and that the EAP is mandatory for all mining dams that store tailings. This law also limited the construction of new tailings dams if communities are established within its self-rescue zone. In this case, the mining company must remove the residents or reinforce the dam structure according to the technical solution approved by the ANM. In 2022, the mining authorities in Brazil enacted a regulation that establishes new procedures related to dams (Resolution ANM 95/2022), which consolidated the safety standards for mining dams, revoking several previous regulations (Ordinance DNPM No. 70,389/2017 and Resolutions ANM No. 13/2019, 32/2020, 40/2020, 51/2020 and 56/2021) and also regulated items by the national legislation (Law No. 14,066/2020), which modified the National Dam Safety Policy.
The changes included the alteration of the assumptions of risk category and emergency level classifications, the inclusion of new suspension and interdiction assumptions, and the creation of new obligations such as the Risk Management Process for Mining Dams (“RMPMD”), for high Associated Potential Damage (“APD”) dams. The RMPMD consists of the risk assessment of the structure in acceptable and not acceptable “As Low as Reasonably Practicable” terms and integrates the management and decision-making related to mining dams.
In 2021, we began implementing the requirements covered by these regulations to all mining dams including certification of the EAP, staff safety trainings, and dam break simulations in accordance with the new regulation.
In 2022, Nexa revised the EAP for all mining dams to adapt to the new Brazilian regulations and considering the new EAP guidelines, detailed by specific terms of reference (Termos de Referência), which were published in 2021. We sent the EAP to all relevant public agencies and published the document on our website. In 2024, we also conducted the Compliance and Operational Evaluation (“COA”) of the EAP for mining, which consists of a legal requirement that aims to certify that the EAPs comply and adhere to the legislation and would be operational in practice in case of an emergency. Thus, the EAP was evaluated by an external company that issued the Compliance and Operability Report (“COR”) and Declaration of Conformity and Operability (“DCO”) of the EAP.
On December 30, 2023, the State of Minas Gerais published State Decree No. 48,747/2023, regulating the environmental recovery policies that companies are required to have in place in the event of an accident or deactivation of a dam, pursuant to a prior state law passed in 2019. Under State Decree No. 48,747/2023, any dams that meet the requirements established under the 2019 Dam Safety Policy law must have an environmental guarantee policy in place. During the second quarter of 2024, the Decree was amended to modify, among other provisions, the deadline for mining companies to indicate the type(s) of guarantee method(s) they would use. The Company complied with this requirement in September 2024. The amendment also established that mining companies must present 50% of the chosen guarantees by the end of 2024. As of December 31, 2024, Nexa estimates that it will require US$19.1 million to cover the applicable dams under this policy. The guarantee can be made by one of the following methods: (i) cash deposit; (ii) CDB; (iii) bank guarantee; or (iv) guarantee insurance. The Company, on December 27, 2024, filed the environmental recovery proposal, contracting for 50% of the guarantee by December 31, 2024, totaling US$9.6 million for all its structures in Minas Gerais through bank guarantees. For 2025, subject to the approval of the environmental agency, an additional 25% must be contracted for by December 31, 2025, and 25% by December 31, 2026, following the schedule previously established by the Decree and the Company expects to comply with this requirement. However, on December 31, 2024, a new Decree was published, further amending the wording of Decree 48,747/2023. This amendment stipulated that the deadline for submitting guarantees would only begin after the environmental agency approves the proposal. Since the new Decree was published after Nexa submitted its guarantees, it will be necessary to await the environmental agency's analysis and address any adjustments required under the revised wording.
Mining Operations
In 2024, a new resolution was published by the State of Minas Gerais (GMG Resolution No. 83, of the Civil Defense), in Brazil, which establishes the minimum requirements for the preparation, analysis and approval of the second section of the Dam Emergency Action Plan (PAE), following the powers of the Civil Defense of Minas Gerais, according to State Decree No. 48,078, of November 5, 2020. This resolution aims to standardize and ensure the effectiveness of emergency measures in dams. Among the main new requirements are the implementation of geotechnical monitoring rooms, which operate 24 hours a day, 7 days a week, in addition to changes in the sounding of alert sirens, which are currently in the process of being implemented in the units of Três Marias, Juiz de Fora and being adapted in Vazante. These new requirements reflect the industry's, and thereby our, focus on improvement of safety and monitoring structures, increasing the efficiency of emergency prevention and response actions at dams.
In Peru, the upstream method has long been an abandoned practice due to seismic concerns in the region. As of 1995, compulsory guidelines were passed prohibiting the use of such method. Subsequently, in 2014 environmental regulators, and later technical regulators, in 2015, adopted the same guidelines prohibiting construction and operation under the upstream method, allowing only the use and construction under the centerline and downstream methods. A specialized governmental agency carries out periodically inspections of tailings dam and mining infrastructure, ensuring technical and environmental regulations are complied with. In addition, mining operations must submit biannual stability studies, to which they are held liable. We follow these guidelines, and all operative tailings dams use the downstream and centerline lift methods.
In December 2023, the Peruvian government issued Supreme Decree No. 034-2023-EM which amended the Occupational Health and Safety in Mining regulation by adding a chapter on management and safety requirements for waste and tailings disposal facilities. The main requirements of the Decree can be summarized as new needs for studies to be carried out, updating the emergency response plan, contemplating a dam break scenario, implementation of alarm systems, among other devices. Most of the items were already or have been implemented. The alarm system is in the implementation phase.
El Porvenir’s tailings dam is currently supported by an authorization for operation up to an altitude of 4,066 meters above sea level (“masl”), which was granted by the Ministry of Energy and Mines on August 28, 2024, the previous authorization was for 4,064 masl. Activities to expand the El Porvenir’s tailings dam to an elevation up to 4,070 masl are underway and the authorization for this new elevation is expected to be obtained by the end of 2025.
For more information, see “Risk factors—Operational risks—The failure of a tailings dam could negatively impact our business, reputation and results of operations, and the implementation of associated regulations and decommissioning processes may be expensive.”
Nexa’s practices
We monitor tailings and waste dams in accordance with international best practice guidelines for management and project design based on criteria set by the International Commission on Large Dams (“ICOLD”) and the Canadian Dam Association (“CDA”) dam safety guidelines. In 2024, all of our tailings dams in Brazil received Stability Condition Declarations (“DCEs”), certifying that these facilities are safe and stable. In Brazil, these certifications are carried out twice a year for mining and smelting dams. In Peru, they occur once a year. As of the date of this annual report, all tailings dams in Peru and Brazil have undergone the certification process, and we concluded a technical report for these dams during the first half of 2024. In addition, all our dams and dry stacking structures are monitored under a system known as theSistema de Gestão de Barragens ou Depósitos/Tailing Dam Management System (“SIGBAR/SIGDEP”), which consists of procedures, tools and key performance indicators, monthly reports and monitoring and analysis by an independent Geotechnical Engineer. The monitoring procedures include regular inspections, as well as internal and external audits.
In addition to the above-mentioned policies and procedures, our SCP committee assists and advises our Board in supporting safe and sustainable business practices in our conduct and activities, as well as in reviewing technical, economic and social matters with respect to our projects.
In 2024, we began the process of implementing standards delineated by the Global Industry Standard Tailings Management (“GISTM”) at the Vazante unit. This is an important step in our tailings management process, as we are focused on incorporating global standards for tailing management into our operations. At the same time, we underwent
Mining Operations
a review process conducted by our first Independent Tailings Review Board (“ITRB”), a process prescribed by GISTM. The main objective of the ITRB is to provide technical and strategic recommendations to ensure the safety and compliance of dams with international best practices, reducing environmental, social and financial risks. The scope of the ITRB assessment varies depending on the applicable company and local legislation but generally includes the assessment of design and construction; operation and maintenance; risk and safety management; regulatory compliance; closure and rehabilitation plan; among others. The ITRB’s function helps increase the transparency and credibility of dam management, and increase satisfaction of the expectations of regulators, investors and local communities. No critical items were found in the ITRB assessment of our tailings management process in Vazante. The main recommendations observed were on tailings governance. We plan to continue implementing the standards delineated by GISTM at other units in 2025.
In 2022, all plans for the units in Brazil were reviewed and filed with their respective government’s environmental agencies, and as of the date of this annual report, approval is pending from the respective environmental agencies. In 2023, we began conducting engineering studies to evaluate the stability and confirm the construction method of old inactive industrial waste containment structures. These structures, since they became inactive more than 20 years ago have been subject to decommissioning as monitored by the environmental agency of the State of Minas Gerais as part of the environmental licensing process for the unit. None of these structures contain mining tailings, water or liquid waste. In 2024, we presented the progress of the studies to the respective state environmental foundation, and we plan to resume discussions in the first half of 2025 to present the results of the studies carried out and define next steps to classify these structures. For more information about our SCP committee and ESG initiatives, see Information on the Company—Environmental, Social and Governance (ESG) and corporate initiatives—Sustainability Committee and Reporting.”
We use four disposal options for tailings. Our preferred option is to convert part or all of the tailings material into a commercially viable product. When the conversion method is not available, we prefer to use the backfill method for our underground mines. This technique involves removing moisture from tailings, creating a mixture with cement and filling open spaces in the mines with this combination. We believe this method reduces safety risks related to tailings disposal given that it provides greater geotechnical stability and does not involve the building of a dam or dry stacking structure.
If neither the conversion nor the backfill method is available, we prefer to use the dry stacking method, which involves removing moisture from tailings and stacking them in layers to form an artificial mount covered with soil and vegetation, causing it to integrate into the local landscape. We use the dry stacking and backfill methods at our Cerro Lindo mine in Peru since the startup of our mine. In 2019, we started operating a dry stacking facility, which substituted the tailings dam in Vazante. As a result of this new structure in the Vazante unit, 70.5% of all our tailings disposal is done either through backfill or dry staking, reducing our exposure to dams. In 2023, we began developing the backfill and dry stacking methods at our Aripuanã unit, which began the ramp-up in July 2022. In February 2023, we started an industrial-scale testing for dry stacking disposal at the Três Marias unit. In 2024, the initiative achieved excellent results successfully filtering the residue and we continued to develop the project during the initial stages of the industrial-scale test, filtering an average of 92.4% of the operation’s material throughout the year. Due to these advancements, we began the licensing process of the dry stacking disposal at Três Marias.
When neither of these three methods is possible, we use tailings dams. The dam acts as a solid barrier engineered to prevent the tailings material from escaping to the environment around the mine. We use this method in Peru at our Cerro Pasco Complex (El Porvenir and Atacocha mines), and at our Cajamarquilla smelter, and in Brazil at our Vazante mine, and Juiz de Fora and Três Marias smelters. We also use a combination of the backfill method and tailings dams at our El Porvenir and Atacocha mines in Peru. At the Aripuanã mine, we have built a water dam to supply water to our plant. This dam is engineered with borrowed material and uses the technical control of compaction of the soil.
We currently raise our tailings dams using the following two methods: (i) the downstream method, where the building material is disposed downstream of the crest of the dam body; and (ii) the center-line method, where the building material is disposed partially downstream and partially upstream of the crest of the dam body, while maintaining the same centerline of the crest. Historically, we have also used the upstream method – where the building material is disposed upstream of the crest of the dam body – in certain instances – however, none of these tailings’ dams are now active.
Mining Operations
In addition, we also use effluent dams, which are dams used to treat water that contains tailings particles or other solid particles. The effluent dams separate the tailings particles or other solid particles from the water by retaining the particles and releasing the clean water downstream.
We currently have 40 disposal facilities, 22 of which are active and 18 inactive (including tailings dams, dry stacking facilities, effluent dams and water storage dams), 18 located in Peru and 22 located in Brazil. We continue to implement responsible tailings management strategies, including backfill methods and dry stacking, to minimize our environmental impact. Additionally, decommissioning and de-characterization efforts are ongoing for non-operational dams, in line with our commitment to sustainable mining practices. The following is an overview of the dams we have in place at our principal mining and smelting facilities:
Peru
| · | At Cerro Lindo, we have no tailings dams, and tailings are disposed of using a combination of the backfill and dry stacking methods; there are two dry stacking facilities and two effluent dams. |
| · | At the Cerro Pasco Complex (El Porvenir and Atacocha), tailings are disposed of using a combination of the backfill method and tailings dams; there are two tailings dams in active use and four non-operational tailings dams, which are in the process of being decommissioned. |
| · | At Cajamarquilla, there are three tailings dams in active use and four non-operational tailings dams, which are in the process of being decommissioned. |
| · | At the Chapi mine property, which was sold on December 23, 2024, there were five non-operational tailings dams, which have already been excluded from the total number of disposal facilities. |
| · | At the Sinaycocha property, which is part of our Atacocha mine property, there is one non-operational tailings dam. |
Brazil
| · | At Morro Agudo, which was sold on July 1, 2024, most tailings were converted for sale, however, there were two products dams and a separate tailings dam, which have already been excluded from the total number of disposal facilities. |
| · | At Vazante, tailings are disposed of using a combination of tailings dams, backfill and dry stacking methods; there is one dry stacking facility, one tailings dam and two effluent dams in active use. |
| · | At Aripuanã, we have no tailings dams, and tailings are disposed of using a combination of the backfill and dry stacking methods; there is one dry stacking facility and one water storage dam in active use. |
| · | At Juiz de Fora, there is one tailings dam in active use, three effluent dams in active use and six non-operational tailings dams, one of which is in decommissioning process, while the other five were decommissioned in 2002 and are currently in the process of de-characterization. |
| · | At Três Marias, there are two tailings dams and one dry stacking facility in active use and three non-operational tailings dams, which are in the process of being decommissioned. |
Smelting Operations
The text of this filing, as the company filed it with the SEC, without its images or exhibits. This is not investment advice.