Nexa Resources SA

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, 2023, 2022, and 2021, we convert the relevant metal contained in concentrate production used in the zinc equivalent grade based on the average benchmark prices for 2023, namely, US$2,649.04 per tonne (US$1.20 per pound) for zinc, US$8,483.40 per tonne (US$3.85 per pound) for copper, US$2,137.18 per tonne (US$0.97 per pound) for lead, US$23.39 per ounce for silver and US$1,942.74 per ounce for gold.

Mining Operations

The following table summarizes the average ore grade for the periods indicated.

Each mine consists of one mine, one treatment plant and related infrastructure. We summarize below information as of December 31, 2023 for each of our six mines, including Aripuanã. 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.”

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.

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.

Mining Operations

All mineral concessions are held in the name of Nexa Peru. The tenure consists of 68 mining concessions totaling approximately 43,827.8 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, 2023, Nexa Peru had a total of six water licenses, one for use of seawater, and the remaining five for ground water extraction.

Cerro Lindo 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 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 2023, mineral exploration in Cerro Lindo focused on extensions of known ore bodies to the southeast of Cerro Lindo and on the Pucasalla target, as well as starting drilling tests at the Patahuasi Millay target, located 500 meters to the northwest of Cerro Lindo mine. Underground activities in 2023 included drilling at OB-8 and OB-9 to extend the known mineralized bodies near the mine, at geophysical anomaly zones in Patahuasi Millay, as well as Pucasalla to find new mineralized zones through surface drilling.

During 2023, we completed approximately 27.5 km of diamond drilling in 29 drill holes, divided between surface and underground exploration drillings. By the end of 2023, the drill holes from surface in Pucasalla target and its extensions confirmed evidence of sulfide mineralization with lens of sphalerite, galena and chalcopyrite in a dacite host rock with gangue of barite. In underground, the focus was to confirm the continuity of the mineralization in orebody OB-8 and OB-9.

During 2024, we expect to complete a total of 23.1 km of exploratory drilling. Our goals are to continue the exploratory drilling program to identify new mineralized zones supported by new access and platforms construction in Patahuasi Millay, Pucasalla and extensions, and continue extending the known orebodies such as OB-8 and OB-9.

In 2023, we spent US$6.8 million in exploration expenses for Cerro Lindo, primarily associated with diamond drilling, geochemistry analysis and geological research works. We have budgeted US$7.8 million for 2024 to continue our exploration program, as data interpretations, geochemistry, geophysical and exploratory drilling campaign.

Mining Operations

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 February 2020 and is operational. The national grid supplies electrical power for the mine site.

In 2023, we spent US$37.7 million on sustaining capital expenditures for Cerro Lindo, primarily associated with mine development, equipment replacement and other major infrastructure projects.

In March 2023, production at the Cerro Lindo mine was suspended due to heavy rainfall levels and overflowing rivers caused by cyclone Yaku, resulting in the partial flooding of some lower levels of the mine. In April 2023, Cerro Lindo resumed operations at full capacity. During the temporary suspension, Nexa remained focused on the security and reparation of the mine and took all measures to ensure the safety and well-being of its employees, contractors and host communities. The temporary suspension of the mine resulted in lower production in 2023 compared to 2022.

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 2023 was lower than 2022 primarily as a result of a two-week production suspension in March due to unusual heavy rainfall levels and lower grades.

Mineral Reserves and Mineral Resources

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.

Mining Operations

Cerro Lindo – Year End Mineral Reserves as of December 31, 2023 (on an 83.48% Nexa attributable ownership basis)(1)

Cerro Lindo – Year End Mineral Reserves as of December 31, 2023 (on a 100% ownership basis)(1)

The Cerro Lindo Mineral Reserves are estimated at an NSR cut-off value of US$40.86/t processed. A number of incremental material (with values between US$32.99/t and US$40.86/t) was included. A minimum mining width of 5.0 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$2,799.04/t (US$1.27/lb); copper: US$7,669.61/t (US$3.48/lb); lead: US$2,000.29/t (US$0.91/lb); and silver: US$21.17/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 average head grades are 88.36% for Zn, 85.23% for Cu, 66.53% for Pb, and 68.78% for Ag. The current life of mine (“LOM”) plan continues to 2030.

Cerro Lindo – Net Difference in Mineral Reserves between December 31, 2023 versus December 31, 2022 (on an 83.48% Nexa attributable ownership basis)

Mining Operations

Cerro Lindo – Net Difference in Mineral Reserves between December 31, 2023 versus December 31, 2022 (on a 100% ownership basis)

In comparison to 2022, Cerro Lindo’s Mineral Reserves slightly decreased by 0.7% in mass to total 41.2 Mt from 41.4Mt and decreased by 5.9% in zinc content (kt), mainly due to a 5.1% 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 and a lower cut-off grade. Mineral Reserve depletion during 2023 represented 6.0Mt containing 90.3kt of zinc.

Cerro Lindo – Year End Mineral Resources as of December 31, 2023 (on an 83.48% Nexa attributable ownership basis)(1)

Cerro Lindo – Year End Mineral Resources as of December 31, 2023 (on a 100% ownership basis)(1)

Mining Operations

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$40.86/t. Mineral Resources estimates are based on average long-term metal prices of: zinc: US$3,218.90/t (US$1.46/lb); copper: US$8,820.05/t (US$4.00/lb); lead: US$2,300.33/t (US$1.04/lb); and silver: US$24.35/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 average head grades are 88.36% for Zn, 85.23% for Cu, 66.53% for Pb, and 68.78% for Ag.

Cerro Lindo – Net Difference in Mineral Resources between December 31, 2023 versus December 31, 2022 (on an 83.48% Nexa attributable ownership basis)

Cerro Lindo – Net Difference in Mineral Resources between December 31, 2023 versus December 31, 2022 (on a 100% ownership basis)

In comparison to 2022, Cerro Lindo’s Measured and Indicated Mineral Resources decreased by 10.5% in mass and by 11.8% in zinc content (kt), mainly due to the conversion to Mineral Reserves. In comparison to 2022, Cerro Lindo’s Inferred Mineral Resources increased by 9.3% in mass and by 2.0% in zinc content (kt), due to infill and brownfield drilling.

Mining Operations

For additional information, see the Technical Report Summary on Cerro Lindo, filed as Exhibit 15.1 to Nexa’s 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 two mining concession applications, two 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 application and seven mining concessions with a total area of 1,864.6 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 three exploration applications totaling 1,140.6 hectares, 36 exploration authorizations totaling 25,647.1 hectares, one right to apply for mining concession totaling 344.5 hectares, one mining concession application totaling 190.0 hectares and one mining concession totaling 52.5 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.

Brazilian companies that hold mining concessions are subject to a royalty payment imposed by the National Mining Agency. For more information, see “Information on the Company—Regulatory matters—Brazilian regulatory framework—Royalties and other taxes on mining activities.”

Nexa Brazil holds nine licenses for water management and water use in the operations. Nexa Brazil has lodged renewal applications, where applicable, for the water management.

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 under renewal process.

Mining Operations

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 2023 were focused on expanding the mineralization of known ore bodies, such as Extremo Norte and Sucuri Norte, and identifying the continuity of mineralized bodies along the Vazante hydrothermal breccia. We are conducting ongoing tests to explore extensions of known mineralization, intensifying drilling in areas near mine where minimal data is currently available, and identifying other areas where mineralization may be present.

In 2023, we completed approximately 7.3 km of diamond drilling, divided between exploratory (1.3 km) and extension drilling (6.0 km). The focus of the near mine extension drilling was on the extension of the Vazante mine ore bodies, exploring the target Extremo Norte and Sucuri Norte, which confirmed the mineralized system and opened lateral and depth continuity. In addition, the mineral exploration team continues to seek to identify new prospective areas, such as Vazante Sul, which confirmed the presence of mineralized breccia more than 10 km from Vazante mine.

In 2024, Nexa intends to continue extending the near mine orebodies such as Sucuri and Sucuri Norte, and to convert inferred resources into indicated resources in the BDMG area, which was acquired in 2022.

In 2023, we spent US$3.5 million on the Cerro Lindo brownfield program for life of mine extension, including drilling program and geological activities. In 2023, we drilled 12 exploration drill holes, totaling 7.3 km. We have budgeted US$4.7 million for the mine during 2024 and we expect to drill 12.4 km.

The Vazante operation consists of two mechanized underground mines, the Vazante mine and Extremo Norte Mine, currently operating at a rate of approximately 1.5 Mtpy. 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, paste-fill plants, and tailings storage facilities.

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 55 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. The power demand by 2026 is expected to reach approximately 55 MW as dewatering demands continue to grow. 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 2023, we spent US$28.0 million on sustaining capital expenditures for this property, primarily associated with mine development, ramp deepening in the “Extremo Norte”, equipment replacement and other major infrastructure. In addition, we invested US$2.5 million in capital expenditures related to the Vazante mine deepening, focusing on expansion. For more information, see “Information on the Company—Mining Operations—Growth Projects—Vazante mine deepening project.”

Mining Operations

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 2023 was higher than 2022 due to higher treated ore volumes and higher zinc grades.

Mineral Reserves and Mineral Resources

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, 2023 (on a 100% ownership basis)** (1)**

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$66.31/t processed. A minimum mining width of 4.0 m. Recoveries for the Vazante mine at average head grades are 87.19% for Zn, 23.93% 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 tailings storage facility (“TSF”) reclaiming plan and budgeting. The Vazante Aroeira Tailings Mineral Reserves are estimated at a NSR cut-off value of US$25.44/t processed. A minimum mining unit of 10m x 10m x 2m was applied. Recoveries for Vazante Aroeira Tailings at average head grades are 67.86% for Zn, 40.74% for Pb, and 42.00% for Ag. Metallurgical recoveries are

Mining Operations

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$2,799.04/t (US$1.27/lb); lead: US$2,000.29/t (US$0.91/lb); and silver: US$21.17/oz. The current LOM plan, based in our current reserves, continues to 2031.

Vazante – Net Difference in Mineral Reserves between December 31, 2023 versus December 31, 2022 (on a 100% ownership basis)

In comparison to 2022, Vazante’s Mineral Reserves decreased by 0.4% in mass and by 9.6% in zinc content (kt), mainly due to geotechnical restrictions in a high-grade area (Lumiadeira). The decrease in mass was lower than the decrease in zinc content due to the conversion of 2.1Mt from Indicated Mineral Resources to Proven Mineral Reserves from the Vazante Aroeira Tailings. Mineral Reserve depletion during 2023 accounted for 1.7Mt containing 184.3kt of zinc.

Vazante – Year End Mineral Resources as of December 31, 2023 (on an 100% ownership basis)(1)

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$66.31/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$23.13/t for soil and US$28.38/t for fresh rock and transition material. The Mineral Resources estimates for the tailings at Vazante are reported considering the material with an NSR value of greater than US$29.40/t which lies above the original topographic surface. Mineral Resources estimates are based on average long-term metal prices of: zinc: US$3,218.90/t (US$1.46/lb); lead: US$2,300.33/t (US$1.04/lb); and silver: US$24.35/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: hypogene head grades are 87.19% for Zn, 23.93% for Pb, and 42.00% for Ag, supergene (calamine) is 55.00% for Zn, and tailings are 67.86% for Zn, 40.74% for Pb, and 42.00% for Ag.

Mining Operations

Vazante – Net Difference in Mineral Resources between December 31, 2023 versus December 31, 2022 (on an 100% ownership basis)

In comparison to 2022, Vazante’s Inferred Mineral Resources decreased by 11.4% in mass and decreased by 7.2% in zinc content (kt), mainly due to geotechnical restrictions. In comparison to 2022, Vazante’s Measured and Indicated Mineral Resources decreased by 58.5% in mass and decreased by 38.6% in zinc content (kt), mainly as a result of the conversion to Mineral Reserves at tailings dams.

For additional information, see the Technical Report Summary on Vazante, filed as Exhibit 15.3 to Nexa’s 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.

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.

Mining Operations

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 life of mine 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 life of mine of both mines.

In 2023, we continued to advance with 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 1Q23 and a FEL3 tailings pumping system study was also completed in 2Q23.

The Integration Project plan includes, among others areas: (i) the restart and rehabilitation of the Atacocha underground mine; (ii) the development of an approximately 2 km long connection tunnel (Tunnel 2900), which will connect the Atacocha underground mine to the bottom of the El Porvenir (Picasso) shaft, allowing the production from both underground mines to be hoisted and fed at the El Porvenir processing plant; (iii) the expansion of the Picasso shaft capacity to support production and extraction from both underground mines; (iv) the closure of the Atacocha processing plant, with the depletion of Atacocha’s open pit Mineral Reserves in 2027; and (v) the construction of a new tailings pumping and pipeline system, which will allow the tailings from the El Porvenir processing plant to be sent to the Atacocha tailings storage facility, providing for a long-term solution for our tailings disposal and supporting the extension of the mine life of the combined mines. Nexa also continues to advance on other work fronts related to the Integration Project, including to obtain the required environmental studies and permits.

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. 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”.

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 of this annual report on Form 20-F. We expect to submit the Integration Project for formal approval by our Sustainability and Capital Projects (“SCP”) committee and our Board of directors in 2024 in order to establish the project’s governance such as: (i) implementation schedule; (ii) organizational chart; (iii) implementation of control routines; (iv) definition of responsibilities for each project component; and (v) cost management implementation.

Mining Operations

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 and, in 2012, production reached its current capacity of 6,500 tonnes 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 subsidiary of Nexa Peru in which Nexa Peru has directly and indirectly a 100% equity interest.

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 2023, the exploration program at El Porvenir was focused on drilling in mineralized zones in the Integration target, seeking to evaluate the mineralization continuity in strike and at depth, with the goal of extending the life of mine. In 2023, we drilled 16 drill holes totaling 9.3 km of exploration drilling, which confirmed the Integration target extensions, with emphasis on the intermediate and lower levels of the unit.

In 2024, we will continue to focus our efforts on expanding mineralized zones in the integration area, with the potential to extend existing Mineral Resources. We expect to also drill other satellite targets such as Don Lucho, Veta AM and Porvenir 9.

Mining Operations

We spent approximately US$1.9 million on the El Porvenir brownfield program in 2023, including the drilling program and geological activities. We have budgeted US$1.6 million for 2024 activities, and we expect to drill 5.5 km.

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.

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 2023, we spent US$68.7 million on sustaining capital expenditures for this property, primarily associated with mine development, the restoration of tailings dams, 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 2023 was higher than 2022 due to higher treated ore volumes and higher zinc grades.

Mining Operations

Mineral Reserves and Mineral Resources

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, 2023 (on an 83.48% Nexa attributable ownership basis)(1)

El Porvenir – Year End Mineral Reserves as of December 31, 2022 (on a 100% ownership basis)(1)

The El Porvenir 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 5.0 m 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. Mineral Reserves were estimated at a NSR cut-off values ranging from US$63.77/t to US$67.04/t for SLS areas and US$65.77/t to US$69.04/t for C&F areas depending on the zone. Mineral Reserves estimates are based on average long-term metal prices of: zinc: US$2,799.04/t (US$1.27/lb); copper: US$7,669.61/t (US$3.48/lb); lead: US$2,000.29/t (US$0.91/lb); and silver: US$21.17/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 average head grades are 89.21% for Zn, 14.60% for Cu, 80.01% for Pb, and 77.51% for Ag. The current LOM plan continues to 2033. We continued to advance with the technical studies to optimize the integration of El Porvenir and Atacocha underground mines, and as a result of the advancements in the technical studies, we increased the overall Mineral Reserves of the Cerro Pasco Complex. For further information see “Information on the Company—Mining Operations—Cerro Pasco Complex—Integration Project.”

Mining Operations

El Porvenir – Net Difference in Mineral Reserves between December 31, 2023 versus December 31, 2022 (on an 83.48% Nexa attributable ownership basis)

El Porvenir – Net Difference in Mineral Reserves between December 31, 2023 versus December 31, 2022 (on a 100% ownership basis)

In comparison to 2022, El Porvenir’s Mineral Reserves decreased by 5.5% in mass, while increased by 7.8% in zinc content (kt). The decrease in mass was mainly due to the increase in NSR cut-off values, while the increase in zinc content was mainly due to higher grades as a result of block model improvements as well as additions from infill drilling. Mineral Reserve depletion during 2023 accounted for 2.2Mt containing 63.5kt of zinc.

El Porvenir – Year End Mineral Resources as of December 31, 2023 (on an 83.48% Nexa Attributable ownership basis)(1)

Mining Operations

El Porvenir – Year End Mineral Resources as of December 31, 2023 (on a 100% ownership basis)(1)

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$63.77/t to US$67.04/t for SLS areas and US$65.77/t to US$69.04/t for C&F areas depending on the zone. Mineral Resources estimates are based on average long-term metal prices of: zinc: US$3,218.90/t (US$1.46/lb); copper: US$8,820.05/t (US$4.00/lb); lead: US$2,300.33/t (US$1.04/lb); and silver: US$24.35/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 89.21% for Zn, 14.60% for Cu, 80.01% for Pb, and 77.51% for Ag.

El Porvenir – Net Difference in Mineral Resources between December 31, 2023 versus December 31, 2022 (on an 83.48% Nexa attributable ownership basis)

Mining Operations

El Porvenir – Net Difference in Mineral Resources between December 31, 2023 versus December 31, 2022 (on a 100% ownership basis)

In comparison to 2022, El Porvenir’s Inferred Mineral Resources increased by 3.6% in mass and by 3.6% in zinc content (kt), mainly due to infill drilling. In comparison to 2022, El Porvenir’s Measured and Indicated Mineral Resources increased by 14.5% in mass and by 22.7% in zinc content (kt), mainly due to infill drilling.

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.

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, and we expect to complete the Integration Project approval process with our technical committee and Board of directors in 2024.

The Atacocha mine is operated by Nexa Resources Atacocha S.A.A., which is controlled by 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.

Mining Operations

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 2023, we spent approximately US$0.2 million on the Atacocha brownfield program for exploration maintenance. In 2023, we had no drilling activities at Atacocha. We have budgeted US$0.4 million for the program during 2024 for maintenance and data interpretations, including 3.0 km of the drilling campaign in the Integration target.

In 2023, we spent US$16.1 million on sustaining capital expenditures for this property, primarily associated with mine development, equipment replacement and other major infrastructure. In addition to US$0.2 million to maintain the Mineral Exploration structure, a drilling program began in 2024 with the focus on continuing extending the mineralization of the integration target.

In January 2023, protest activities by the Machcan community temporarily suspended operations at the Atacocha San Gerardo open pit mine for approximately one week. In June 2023, protest activities by the Machcan community again blocked access to the Atacocha San Gerardo open pit mine, temporarily suspending production for approximately one month. Operations resumed at the end of July 2023 once protest activities ceased. Finally, 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. In each instance, mining activities were limited to critical operations with a minimum workforce to ensure appropriate maintenance, safety and security. Despite these blockages, the Atacocha mine operated at high levels of capacity utilization rates throughout the year and 2023. In each of these instances, the 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.

Production

The Atacocha mine has a treatment plant capacity of 4,400 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 2023 was lower than in 2022 due to the temporary suspension of production due to illegal protest activities occurring in different periods throughout first half of 2023.

Mining Operations

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, 2023 (on an 75.96% Nexa attributable ownership basis)(1)

Atacocha Underground – Year End Mineral Reserves as of December 31, 2023 (on a 100% ownership basis)(1)

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 5.0 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$69.00/t for SLS areas and US$71.07/t for C&F areas depending on the zone. A number of incremental material (with values between US$45.09/t and US$69.00/t for SLS and values between US$47.16/t and US$71.07/t for C&F mining) was included in the estimate. Mineral Reserves estimates are based on average long-term metal prices of: zinc: US$2,799.04/t (US$1.27/lb); copper: US$7,669.61/t (US$3.48/lb); lead: US$2,000.29/t (US$0.91/lb); and silver: US$21.17/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 average head grades are 89.30% for Zn, 15.73% for Cu, 80.02% for Pb, and 77.51% for Ag. The current LOM plan continues to 2033. The current LOM production planning goes from 2027 to 2033. We continued to advance with the technical studies to optimize the integration of El Porvenir and Atacocha underground mines, and as a result of the advancements in the technical studies, we increased the overall Mineral Reserves of the Cerro Pasco Complex. For further information see “Information on the Company—Mining Operations—Cerro Pasco Complex—Integration Project.”

Mining Operations

Atacocha Underground – Net Difference in Mineral Reserves between December 31, 2023 versus December 31, 2022 (on an 75.96% Nexa attributable ownership basis)

Atacocha Underground – Net Difference in Mineral Reserves between December 31, 2023 versus December 31, 2022 (on a 100% ownership basis)

In 2023, Atacocha’s Underground Mineral Reserves increased compared to 2022 due to the declaration of Mineral Reserves for the first time since 2019.

Atacocha Underground – Year End Mineral Resources as of December 31, 2023 (on an 75.96% Nexa Attributable ownership basis)(1)

Mining Operations

Atacocha Underground – Year End Mineral Resources as of December 31, 2023 (on a 100% ownership basis)(1)

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$69.00/t for SLS areas and US$71.07/t for C&F areas depending on the zone. Mineral Resources estimates are based on average long-term metal prices of: zinc: US$3,218.90/t (US$1.46/lb); copper: US$8,820.05/t (US$4.00/lb); lead: US$2,300.33/t (US$1.04/lb); and silver: US$24.35/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 77.51% for Ag.

Atacocha Underground – Net Difference in Mineral Resources between December 31, 2023 versus December 31, 2022 (on an 75.96% Nexa attributable ownership basis)

Mining Operations

Atacocha Underground – Net Difference in Mineral Resources between December 31, 2023 versus December 31, 2022 (on a 100% ownership basis)

In comparison to 2022, Atacocha’s Underground Inferred Mineral Resources decreased by 0.6% in mass and by 8.6% in zinc content (kt), mainly due to a classification revision. In comparison to 2022, Atacocha’s Underground Measured and Indicated Mineral Resources decreased by 49.5% in mass and by 59.3% in zinc content (kt), mainly due to the conversion to Mineral Reserves.

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, 2023 (on an 75.96% Nexa attributable ownership basis)(1)

Atacocha Open Pit – Year End Mineral Reserves as of December 31, 2023 (on a 100% ownership basis)(1)

Mining Operations

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$16.21/t. Mineral Reserves estimates are based on average long-term metal prices of: zinc: US$2,799.04/t (US$1.27/lb); lead: US$2,000.29/t (US$0.91/lb); silver: US$21.17/oz; and gold: US$1,630.93/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 average head grade are 70.44% for Zn, 83.97% for Pb, 75.76% for Ag, and 65.46% for gold. The current LOM plan continues to 2027. We continued to advance with the technical studies to optimize the integration of El Porvenir and Atacocha underground mines, and as a result of the advancements in the technical studies, we increased the overall Mineral Reserves of the Cerro Pasco Complex. For further information see “Information on the Company—Mining Operations—Cerro Pasco Complex—Integration Project.”

Atacocha Open Pit – Net Difference in Mineral Reserves between December 31, 2023 versus December 31, 2022 (on an 75.96% Nexa attributable ownership basis)

Atacocha Open Pit – Net Difference in Mineral Reserves between December 31, 2023 versus December 31, 2022 (on a 100% ownership basis)

In 2023, Atacocha’s Open Pit Mineral Reserves increased compared to 2022 due to the declaration of Mineral Reserves for the first time since 2019.

Atacocha Open Pit – Year End Mineral Resources as of December 31, 2023 (on an 75.96% Nexa Attributable ownership basis)(1)

Mining Operations

Atacocha Open Pit – Year End Mineral Resources as of December 31, 2023 (on a 100% ownership basis)(1)

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$22.44/t. Mineral Resources estimates are based on average long-term metal prices of: zinc: US$3,218.90/t (US$1.46/lb); lead: US$2,300.33/t (US$1.04/lb); and silver: US$24.35/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 average head grades are 70.44% for Zn, 83.97% for Pb, 75.76% for Ag, and 65.46% for Au.

Mining Operations

Atacocha Open Pit – Net Difference in Mineral Resources between December 31, 2023 versus December 31, 2022 (on an 75.96% Nexa attributable ownership basis)

Atacocha Open Pit – Net Difference in Mineral Resources between December 31, 2023 versus December 31, 2022 (on a 100% ownership basis)

In comparison to 2022, Atacocha’s Open Pit Inferred Mineral Resources decreased by 55.7% in mass and by 50.2% in zinc content (kt), mainly due to the limits of pit shell constraint. In comparison to 2022, Atacocha’s Open Pit Measured and Indicated Mineral Resources decreased by 43.5% in mass and by 41.1% in zinc content (kt), mainly due to the conversion to Mineral Reserves.

Aripuanã

Location and means of access

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 we still do not have a scheduled date for completion. 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 gain of US$2.3 million in the income statement for the period ended on December 31, 2023. For further details on the offtake agreement, see Note 16 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. 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 (1,387.2 hectares), one right to apply for mining concession, (1,000.0 hectares) and nine exploration authorizations (27,025.9 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 issued by the Environmental Agency from the state of Mato Grosso is valid until October 2024 and will undergo the renewal process in 2024.

Mineralization

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 2023, 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 mineral exploration efforts to upgrade the Mineral Resources at the Babaçu target and expand our Mineral Reserves.

The exploratory drilling in 2023 was focused on the infill drilling of the Babaçu target, which is located southeast of the Ambrex orebody, extending the mineralization with high zinc, lead and copper content, which aimed to update the classification and conversion of resources into reserves, as well as starting drilling tests at the Massaranduba target, located southeast of Aripuanã mine.

In 2023, we spent a total of US$7.3 million on the Aripuanã mine, with US$2.0 million spent towards Aripuanã’s exploration program and US$5.2 million on an infill drilling campaign. The total investment included drilling, geological activities, geochemistry, and more. In 2023, we drilled 21.8 km of diamond drilling, including Babaçu infill drilling and Massaranduba exploratory drilling. For 2024, we expect to invest US$4.0 million in the brownfield exploration program to drill 9.0 km focused on the Massaranduba target to validate the presence of mineralization in the southeastern extension of the Aripuanã deposit.

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. Ramp-up activities continue to progress and are expected to conclude in mid-2024.

The commissioning of the paste fill circuit was completed in December 2022, the first tests of mine filling started in January 2023 and were concluded in February 2023, with the paste plant becoming fully operational only in 2024. In January and February of 2023, the processing plant performed at around 57% of nameplate capacity. Ramp-up activities focused on steadily increasing the plant throughput rate, asset reliability, as well as concentrate grades and quality. At the end of 2Q23, the plant performed at an average of 76% of nameplate capacity while the average utilization rate was 66%.

In March 2023, we decided to temporarily halt operations at the plant to address some design limitations in the capacity of the flotation pumping system, identified during the detection of bottlenecks, which required resizing and upgrade, along with certain plant processing facilities and systems, as well as the clean-up and upgrading of water treatment facilities, which contributed to a better resiliency during the rainy season (which typically occurs from December to March). Due to the aforementioned limitations, in 3Q23 we reduced plant throughput, and as a result, the utilization rate was also reduced in the period and the plant performed at an average of 56% in the quarter. Despite this reduction, our priority throughout 2023 was to continue improving metal recovery and concentrate quality and grades, aiming to achieve a stable operation and to minimize impacts related to the necessary extension of the ramp-up phase.

Mining Operations

In 4Q23, we achieved an average of 61% of capacity utilization level and we expect to reach nameplate capacity in mid-2024. At the end of February 2024, the average capacity utilization rate was around 61%, maintaining similar levels as in 4Q23, given the usual rainy season period in the region, which impacted our dry disposal capacity. However, during this period the operational focus was to maintain concentrate quality and grades, as well as the metallurgical recovery rates.

At the end of 2023, approximately 106.6kt of ore was stockpiled. Horizontal mine development reached an accumulated of 7,474 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, 2023, 814 people were employed at Aripuanã. Of these employees, 23.7% are women. We also continued the qualification program for future mine and plant operating professionals, which had 146 candidates enrolled in 2023, of which 46 obtained professional qualifications in the areas of maintenance and automation, and geology and surveying. The company hired 65.8% (96) of the attendees from the qualification program, of which 52.1% (50) are men and 47.9% (46) are women.

To date, cumulative incurred expansion capital expenditures on the mine total US$632.7 million, and we did not make any new expansion capital expenditures on the mine in 2023.

The Aripuanã operation consists of two mechanized underground mines, the Arex Mine and Link Mine, with a rate of approximately 2.3 Mtpy. Production drilling operations have been performed by company personnel using a variety of drilling machines throughout the history of the Aripuanã mine.

The Aripuanã underground mine has been in operation since 2019 and is a fully mechanized mine using rubber-tired diesel equipment for development and production activities. Access to the mine is through one portal for Arex and one portal for Link. 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 process plant/concentrator, conveyor systems, waste rock facilities, temporary ore stockpiles, paste-fill plants, and tailings storage facilities.

The Aripuanã mine is connected to the basic grid at 230 kV. The energy measurement and billing system takes place in SE Dardanelos, 20 km are covered at 69 kV to the unit. Power distribution is carried out at 13.8 kV and the unit has a 25/31 MW transformer. Currently, the power demand contracted with Energisa for the unit is 23 kV, on and off-peak. There are also five 750 kVA diesel generators.

In 2023, we spent US$79.4 million on sustaining capital expenditures for this property, primarily associated with ongoing ramp-up activities, mine development, construction of a waste pile, equipment replacement and other major infrastructure.

The Aripuanã mine is in ramp-up phase 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 2023 was higher than 2022 due to the continued progress of the ramp-up phase which was focused on steadily increasing the plant throughput rate, asset reliability, as well as concentrate grades and quality.

Mining Operations

Mineral Reserves and Mineral Resources

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.

Aripuanã – Year End Mineral Reserves as of December 31, 2023 (on a 100% ownership basis)(1)

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$63.40/t processed was estimated from forecasted operating costs and some incremental material between US$49.20/t and US$63.40/t was included. A minimum mining width of 4.0 m was used. 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$2,799.04/t (US$1.27/lb); copper: US$7,669.61/t (US$3.48/lb); lead: US$2,000.29/t (US$0.91/lb); silver: US$21.17/oz; and gold: US$1,630.93/oz. Metallurgical recoveries are accounted for in NSR calculations based on metallurgical testworks and are variable as a function of head grade and oretype. Recoveries at Life of Mine average head grades for a Mix of 80% Stratabound and 20% Stringer material are 90.06% for Zn, 60.00% for Cu, 84.92% for Pb, 68.00% for Ag, and 67.80% for Au. The current LOM plan continues to 2036.

Mining Operations

Aripuanã – Net Difference in Mineral Reserves between December 31, 2023 versus December 31, 2022 (on a 100% ownership basis)

In comparison to 2022, Aripuanã’s Mineral Reserves increased by 3.2% in mass and by 31.3% in zinc content (kt), mainly due to infill drilling at the Babaçu area, focused on the conversion from Inferred Mineral Resources to Indicated Mineral Resources, enabling the increase in Probable Mineral Reserves. Mineral Reserve depletion during 2023 accounted for 1.5Mt containing 43.9kt of zinc.

Aripuanã – Year End Mineral Resources as of December 31, 2023 (on a 100% ownership basis)(1)

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 for 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$63.40/t. Mineral Resources estimates are based on average long-term metal prices of: zinc: US$3,218.90/t (US$1.46/lb); copper: US$8,820.05/t (US$4.00/lb); lead: US$2,300.33/t (US$1.04/lb); silver: US$24.35/oz and gold: US$1,696.11/oz. Metallurgical recoveries are accounted for in NSR calculations based on metallurgical test work and are variable as a function of head grade and oretype. Recoveries at the LOM average head grades for stratabound material are 90.06% for Zn, 84.92% for Pb, 60.00% for Cu, 75.10% for Ag, and 67.80% for Au. Recoveries at the LOM average head grades for stringer material are 88.68% for Cu, 50.00% for Ag, and 63.00% for Au.

Mining Operations

Aripuanã – Net Difference in Mineral Resources between December 31, 2023 versus December 31, 2022 (on a 100% ownership basis)

In comparison to 2022, Aripuanã’s Inferred Mineral Resources increased by 0.5% in mass and increased by 44.7% in zinc content (kt) in 2023, mainly due to infill drilling at Babaçu resulting in higher average grades. In comparison to 2022, Aripuanã’s Measured and Indicated Mineral Resources increased by 87.8% in mass and increased by 228.9% in zinc content (kt) in 2023, primarily due to infill drilling at Babaçu resulting in higher average grades.

For additional information, see the Technical Report Summary on Aripuanã, filed as Exhibit 15.4 to Nexa’s annual report on Form 20-F/A for the year-ended December 31, 2020, as filed on November 4, 2021.

Morro Agudo

The Morro Agudo Complex consists of an underground mine and open pit, polymetallic mine, as well as three deposits along what is known as the Ambrósia Trend (Ambrósia Sul, Ambrósia Norte, and Bonsucesso). The Morro Agudo mine site is situated on Traíras Farm, about 45 km south of the municipality of Paracatu, Brazil, at a latitude of approximately -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). The Ambrósia Trend deposits are situated about 15 to 20 km northeast of Paracatu.

Nexa Brazil owns 100% of Morro Agudo. The total Morro Agudo mine area is about 80 km long and 10 km wide at the widest extent and covers a significant strike extent of the lithologies that host mineralization at the Morro Agudo mine and along the Ambrósia Trend.

On March 19, 2024, Nexa announced the suspension of its mining operations in the Morro Agudo Complex effective May 1, 2024 until further notice. Between March 19 and April 30, 2024, mining activities will be reduced while limestone production activities will continue at full capacity. The suspension is part of Nexa’s portfolio optimization process to improve free cash flow in line with the Company’s disciplined capital allocation framework, along with its long-term strategy to maximize value for the Company and its shareholders. Nexa is committed to carrying out a structured process, aiming to minimize impacts on the business and, particularly, on its employees and host communities.

Nexa Brazil holds three granted mining concessions in the Morro Agudo mine area of approximately 1,446.1 hectares. In the Ambrósia Trend area, Nexa Brazil has three granted mining concessions totaling 2,495.8 hectares.

Nearby the Morro Agudo mine site and Ambrósia trend areas, Nexa Brazil also holds 44 exploration authorizations totaling 41,414.3 hectares, one right to apply for mining concession totaling 917.0 hectares, three mining applications totaling 2,167.4 hectares and one mining concession totaling 1,000.0 hectares, in addition to the core tenements.

The Morro Agudo operation holds several permits in support of the current operations. The main instrument to regulate the operation is a set of operating licenses issued by the Environmental Agency from the state of Minas Gerais. The licenses are active, some of them under renewal process.

Mining Operations

The Ambrósia mine in Morro Agudo reached the end of its life of mine during the fourth quarter of 2020 and operations were suspended due to the uncertainties associated with the geological model of the area, safety considerations and a greater movement of ore compared to the original plan.

In 2023, we spent US$2.8 million on sustaining capital expenditures for this property, primarily associated with the mine development and maintenance of plant and equipment.

Mineralization Developments

In 2023, no exploratory drilling was carried out in the Morro Agudo area, and for 2024 no exploration activity is expected.

Morro Agudo does not currently have any estimated Mineral Reserves and is considered an exploration stage property under S-K 1300. Morro Agudo is not considered a material property for the purposes of S-K 1300.

The Morro Agudo mine has a treatment plant capacity of 3,400 tonnes of mill feed per day. The table below summarizes the Morro Agudo mine’s concentrate production, metal contained in concentrates produced and average grades for the periods indicated.

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% for zinc contained in concentrate and 97% for copper contained in concentrated minus treatment charges.

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

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 2023 totaled US$2.5 million and we expect to invest an additional US$2.4 million in 2024. This 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 is now expected to be completed in the second half of 2025.

Mining Operations

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. During 2020 and 2021, we assembled and commenced operating the EB347 pumping station and progressed the activities of CEMIG’s electric power line; however, phase 2 of the EB-140 was rescheduled in 2022 due to hydrogeological studies. In 2023, we prepared the area to receive the equipment in accordance with the project’s specifications, in 2024 we expect to complete activities in accordance with the updated project schedule and we expect the pumps to be installed in the second half of 2025.

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 life of mine of the two mines. We expect to submit the project to the formal approval process with our Sustainability and Capital Projects (“SCP”) committee and our Board of directors in 2024. For further information see “Information on the Company—Mining Operations—Cerro Pasco Complex—Integration Project.”

Bonsucesso

The Bonsucesso project is a brownfield underground mine project that belongs to the Morro Agudo complex (Ambrósia Trend). The project is located 8 km north of the Ambrósia Sul mine and approximately 60 km north of the Morro Agudo mine.

In 2023, we had no exploratory activities in the Bonsucesso project and no activities are expected for 2024.

The feasibility study concluded in 2022 with no amount invested in 2023. The total investments related to this project, as of December 31, 2023, totaled US$12.8 million, which includes all project studies (from the scoping study to the feasibility study) and anticipated 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

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 a large, irregularly shaped block of contiguous concessions and two smaller, non-contiguous single concessions. The Magistral Project comprises 36 granted concessions, totaling 16,254.2 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. An EIA modification is currently under the government approval process.

Mining Operations

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% over the unexecuted minimum investment commitment. As of December 31, 2023, the unexecuted minimum investment commitment was US$323.0 million, and if not completed the penalty exposition 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$0.5 million on the Magistral project in 2023.

The feasibility study of the Magistral project was conducted in 2022 and in 2023, we advanced withthe EIA amendment review process by responding to inquiries from the Ministry of the Environment(SENACE). We continue to assess strategic risk-return alternatives to the project by taking into consideration capital allocation decisions and free cash flow generation. In 2024, we expect the final decision relating to the EIA amendment request, which was submitted to SENACE in November 2023 for its assessment.

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.

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 on since then and no exploratory drilling program is scheduled for 2024.

Mining Operations

Hilarión

The Hilarión project is located in the Department of Ancash, 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 72 mineral concessions covering an area of approximately 15,841.2 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 drilled 5 drill holes totaling 4.6 km, completed the sampling for metallurgical test studies, and filed a preliminary economic assessment (“PEA”) for the Hilarión project. In 2021, we executed 21.3 km of diamond drilling to test Hilarión Sur target, totaling 32 drill holes confirming the southeast continuity of the Hilarión deposit towards the edge of the Hilarión stock with multiple thick intersections, in addition to 0.3 km remaining from the 2020 drilling campaign. In 2022, we completed mineral exploration activities including a geological review of recent project data, an aero magnetometry survey to structure the drilling program, found new mineralized zones and expanded the known mineralization at Hilarión West, and drilled 7.2km at the Hilarión West, confirming the presence of mineralization to the west of known bodies and their continuities.

In 2023, we spent approximately US$4.2 million on the Hilarión project, including project maintenance, geology works and drilling campaigns. We completed 4.1 km of diamond drilling, and the focus of the exploratory activities was to identify the mineralization continuity of the deposit in the southeast direction, at the Chaupijanca target, in addition to searching for zones with higher copper content at the El Padrino target.

In 2024, we have budgeted US$1.6 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 13 contiguous mining concessions, covering approximately 10,700.0 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, 2023, 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.

In 2021, field work focused on mapping access road from 0 km up to 19.5 km; and mapping, sampling and topographic survey of Teodolfo, Matias, Berny, and Pizarro targets, in addition to a new mineral occurrence named Aron, as well as metallurgical testing using historic drill core material.

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.

Mining Operations

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, construction and maintenance of the motorized trail, which aims to reach La Florida Annex, commenced and is expected to be completed in 2024.

We spent approximately US$3.6 million on this project in 2023 to drill 1.4 km and we have budgeted US$2.0 million for the Florida Canyon project in 2024, including road maintenance and construction of the final stretch that connects the road to the main exploration camp in the drilling area, maintenance of the project structure, and social programs. No drilling activities are planned for 2024.

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 560,078.1 hectares in 26 exclusive prospective licenses (“EPL”) for the Otavi and Namibia North 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.

To date, we are defining the budget for the project as part of a joint venture with “JOGMEC” as the Japanese fiscal year ends in March 2024. Nexa is currently focusing on mapping and defining regional opportunities and we plan to execute a geophysical survey at Tsumeb Block, conduct exploratory drilling in Tsumeb East and define opportunities in the Namibian Kalahari Copperbelt throughout 2024.

Permits & authorizations for greenfield projects

The following table summarizes the status of the main permits and authorizations for our greenfield projects.

Mining Operations

Tailings disposal

Regulatory framework

We are subject to several environmental regulations related to the use of tailings dams and effluent dams.

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 was built using the upstream method and belongs to Vale S.A. 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 deposit. The initiative achieved excellent results, filtering an average of 74% of the operation’s material throughout the year. In December 2023, filtration reached more than 90% and from 2024 onwards, we expect filtration to reach between 95% and 100%. 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 the promising progress of the dry disposal tests and the difficulties in licensing new dams and dam expansion projects, we canceled the licensing request that was in progress in Três Marias for the Central and West 1 module of the Murici Deposit to begin the licensing process of the dry stacking disposal.

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.

Mining Operations

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 2023, 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. Nexa estimates that it will require US$27.3 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 has until March 29, 2024 to submit an environmental recovery proposal and must contract for 50% of the policy by December 31, 2024, 25% by December 31, 2025 and 25% by December 31, 2026 and expects to comply with this requirement.

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.

El Porvenir’s tailings dam is currently supported by an authorization for operation up to an altitude of 4,064 meters above sea level (“masl”), which was granted by the Ministry of Energy and Mines on May 25, 2023, the previous authorization was for 4,062 masl. Activities to expand the El Porvenir’s tailings dam to an elevation up to 4,066 masl are underway and the approval process for the operation will begin in April 2024, and it is expected to last up to 3 months.

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 2023, 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 have undergone the certification process, and we concluded a technical report for these dams during the first half of 2023. In addition, all our dams and dry stacking structures are monitored under a system known as the Sistema 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.

Mining Operations

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 2020, management reviewed the EAP for all mining dams in accordance with the new Brazilian regulations released midway through 2020 and we trained our internal team in these new procedures. New EAP guidelines, detailed by specific terms of reference, were published in April, May and June 2021. 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 confirm the construction method of inactive industrial waste containment structures that have been closed for more than 20 years.

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. We use this method at our Morro Agudo mine, where most of the tailings that we produce are ZinCal, a limestone rich in zinc that is used as fertilizer, which we sell, not requiring the disposal of tailings materials.

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 mountain 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. With this new structure, over 74.1% of our tailings disposal is done either through backfill or dry staking, reducing our exposure to dams. We are currently developing the backfill and dry stacking methods at our Aripuanã unit, which began the ramp-up in July 2022, and in February 2023 we started industrial-scale testing for dry stacking disposal at the Três Marias unit.

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 El Porvenir and Atacocha mines and at our Cajamarquilla smelter, and in Brazil at our Vazante and Morro Agudo mines 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.

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. Finally, we use products dams for the provisional storage of ZinCal prior to its sale.

Mining Operations

We currently have 24 active and 25 inactive disposal facilities (including tailings dams, dry stacking facilities, effluent dams and products dams),24 located in Peru and 24 located in Brazil, and we also have one water storage dam at the Aripuanã unit. The following is an overview of the dams we have in place at our principal mining and smelting facilities:

Peru

Brazil

Smelting Operations