5E Advanced Materials, Inc.

Fort Cady Project (AKA 5E Boron Americas Project)

The Project is located in the Mojave Desert region in the high desert in eastern San Bernardino County, California, approximately 36 miles east of Barstow, near the town of Newberry Springs and two miles south of I-40. The Project lies approximately 118 miles northeast of Los Angeles, California, or approximately half-way between Los Angeles and Las Vegas, Nevada. Access to the Project is eastbound from Barstow on I-40 to the exit for Hector Road. From the Hector Road exit, travel continues south to the National Trails Highway, then east approximately one mile to County Road 20796, then south for 2.2 miles on County Road 20796 to an unnamed dirt road bearing east for another 1.1 miles to the mine office and plant site at the Project.

The Project area operates with electricity and is well served by other infrastructure, including I-40 and the main Burlington Northern Santa Fe (“BNSF”) rail line that runs from Chicago, Illinois to Los Angeles, California running immediately north alongside I-40. There are three main natural gas transmission lines along the I-40. The two southern transmission lines are owned and operated by SCE, while the northern transmission line is owned and operated by Kinder Morgan. The ports of Los Angeles, Long Beach and San Diego are all within a half-day drive from the Project on major highways. The Project will likely attract personnel from the Barstow-Victorville area.

The Project deposit is in a prospective area for borate and lithium mineralization and is fundamental to our strategy to become a globally integrated supplier of borates, lithium carbonate and advanced boron derivatives. The deposit mineralization is colemanite and the Project has a similar geological setting to U.S. Borax, Inc.’s open-pit mine and Nirma Limited’s Searles Lake operations, situated approximately 75 miles west-northwest and 90 miles northwest of the Project, respectively.

Mineral Title

We own fee simple (private) lands in Sections 25 and 36 of Township 8 North, Range 5 East of the San Bernardino Principal Meridian. An electrical transmission corridor, operated by SCE, tracts from the northeast to the southwest through the fee lands with SCE having surface and subsurface control to a depth of 500 feet, affecting approximately 91 acres of surface lands in the two sections. While this limits surface access to the land, mineralization remains accessible as the ore body occurs at depths greater than 1,000 feet.

We currently hold 30 unpatented lode claims, 117 unpatented placer claims, and two unpatented millsite claims with the BLM within the DOI. Two lode claims were originally filed by Duval Corporation (“Duval”) in 1978 with the other 28 lode claims filed by the Company in January 2025 (11 lode claims) and in August 2025 (17 lode claims). Subsequently, in February 2026, we revised certain of the claims to perfect recording in San Bernardino County, California. Placer claims were filed between October 29, 2016, and February 24, 2017. A review of the BLM Mineral & Land Record System database shows claim status as filed with the next assessment fees due annually on September 1, 2027.

Lastly, 272 acres of land located in Section 36 of Township 8 North, Range 5 East of the San Bernardino Principal Meridian, are split estate, with the surface estate owned by us and the mineral estate is owned by the State of California. These lands are available to us through a mineral lease from the California State Lands Commission. We own the remaining lands, with the minerals underlying the transmission line available subsurface.

Overview of Mining Locations

Fort Cady History

Discovery of the Project borate deposit occurred in 1964 when Congdon and Carey Minerals Exploration Company found several zones of colemanite, a calcium borate mineral, between the depths of 1,330 feet to 1,570 feet below ground surface in Section 26. In September 1977, Duval initiated land acquisition and exploration activities near Hector, California. By March 1981, Duval had completed 34 exploration holes, plus one potential water well. After evaluation of the exploration holes, Duval considered several mining methods. Subsequent studies and tests performed by Duval indicated that in-situ mining technology was feasible.

Duval commenced limited testing and pilot-scale solution mining operation in June 1981. Mountain States Mineral Enterprises, Inc. (“MSME”) purchased the Project from Duval in 1985. In July 1986, tests were initiated by MSME, where dilute hydrochloric acid solution was injected into the ore body. The acid dissolved the colemanite and was then withdrawn from the same well. Between 1981 and 2001, the various owners of the Project drilled an additional 17 wells, which were used for a series of injection testing and pilot-scale operations.

An additional phase of pilot plant operations was conducted between 1987 and 1988. The test results were positive; thus, the Project was viewed as commercially viable. MSME sold the Project to Fort Cady Mineral Corporation (“FCMC”) in 1989. In preparation for the permitting process, feasibility studies, detailed engineering and test work were completed by FCMC.

In 1990, a Plan of Operations (“PoO”) was submitted to the BLM and a Mining Conditional Use Permit and Reclamation Plan was submitted to San Bernardino County, which triggered environmental review under NEPA and CEQA. With the Project located on both public and private lands, the public lands are managed by the BLM in accordance with Surface Management Regulations of the Federal Land Policy and Management Act and federal environmental laws, and the private lands administered by San Bernardino County Land Use Services (“SBC-LUS”) in accordance with the California Surface Mining and Reclamation Act, the County Development Code and state environmental laws.

Based upon the activities described in the PoO, under the NEPA regulations, the BLM determined that an EIS was required while under CEQA, SBC-LUS determined that an Environmental Impact Report (“EIR”) was required. Under a Memorandum of Understanding, the two agencies completed a joint EIS and EIR to satisfy their environmental review requirements under NEPA and CEQA, respectively. The EIS and EIR process followed clearly defined requirements for public participation in studies, such as threatened and endangered species, cultural resources, light, noise, and impacts to local communities. The studies were completed, as was the public participation process, which resulted in a 1994 ROD from the BLM that approved the PoO and approval of the Mining Conditional Use Permit and Reclamation Plan from the SBC-LUS.

A second phase of pilot plant operations occurred between 1996 and 2001, during which approximately 2,200 tons of a synthetic colemanite product, marketed as CadyCal 100, were produced. Commercial-scale operations were not commissioned due to low product prices and other priorities of the controlling entity. For many years, boron was used in traditional applications such as cleaning supplies and ceramics, which did not formulate into a strong pull-side demand investment thesis where pricing justified further development of the Project.

In 2017, a group of Australian investors identified the Project and formed the investment thesis that the boron market had similar dynamics to the lithium market a decade earlier. Like the lithium market ten years prior, the market was dominated by a few companies with a compelling pull-side demand growth story fueled by future-facing applications targeting decarbonization and critical materials. Prior to lithium-ion batteries and electric vehicles, lithium was used in traditional everyday applications like boron’s use in recent years. As a result of the investment thesis that boron is expected to experience a supply deficit relative to demand, the group of Australian investors formed ABR and issued shares to Atlas Precious Metals in exchange for Fort Cady (California) Corporation, the entity holding the permits, mineral and property rights of the Project. In 2017, ABR underwent an initial public offering on the ASX and progressed exploration and development of the Project. In September 2021, ABR created a subsidiary, 5E Advanced Materials, Inc., and through the Scheme, reorganized the Company which placed the Company at the top of the corporate structure. Upon 5E Advanced Materials, Inc. becoming the parent company of the organization, in March 2022, we direct listed on the Nasdaq and became an issuer with the U.S. Securities and Exchange Commission.

In total, we have spent in excess of $172 million on the Project thus far, including resource drilling, monitoring wells, metallurgical test works, well injection tests, permitting activities, construction and operation of the SSF, pilot-scale test works, engineering and vendor testing related to the proposed Commercial-Scale Facility and wellfield testing and development activities.

Access and Infrastructure

We continue to develop operating infrastructure for the Project in support of extraction and processing activities. A manned gate is located on the Project access road and provides required site-specific safety briefings and monitors personnel entry and exit to the site. Personnel are predominantly sourced from the surrounding area including Barstow and Victorville, California.

The BNSF rail line from Las Vegas, Nevada to Los Angeles, California runs parallel to I-40 and is adjacent to the Project. A rail loadout is located approximately 1.2 miles north of the National Trails Highway on a road that bears north and located 0.4 miles west of San Bernardino County Road 20796. San Bernardino County operates six general aviation airports with the closest airport to the Project being the Barstow-Daggett Airport located approximately 23 miles west of the Project off the National Trails Highway. Commercial flight service is available through five airports in the greater Los Angeles area and in Las Vegas, Nevada. A dedicated cargo service airport is located approximately 65 miles southwest of the Project.

The construction of the SSF was performed by a construction contractor with additional local resources supporting construction contracting, construction materials, energy sources, employees, and housing. The Project has good access to I-40 which connects it to numerous sizable communities between Barstow, California and the greater Los Angeles area offering excellent access to transportation, construction materials, labor, and housing. The Project was successful in removing natural gas generators from the facility and is currently supplied by approximately one megawatt of shore power that is sufficient for mine office, storage facilities on site, and the operation of the SSF. An electrical transmission corridor operated by SCE extends northeastward through the eastern part of the Project. The Project has two water wells located nearby to support in-situ leaching operations where unpatented millsite claims are filed. Currently, no natural gas is connected to the Project, but we have a proposal from a major U.S. interstate natural gas transmission system operator to connect to the Mojave Pipeline. Two other natural gas transmission lines run along I-40 near the Project.

The plant site currently has a 2,000 square foot control room and office building, a 1,000 square foot administrative building, storage buildings, warehouse, an analytical laboratory, an approximately 20-acre production facility (the SSF), four injection/recovery wells, and an intended gypsum storage area occupying 17 acres. Gypsum is a byproduct of past pilot plant production and is intended, along with calcium chloride, to be a future co-product that can be sold to the regional market.

Project Permits and Reclamation Requirements

We currently have the following Project permits in place:

The MDAQMD has issued operating permits for the SSF and the permits are renewed annually. After front-end engineering and design and during detail design of the proposed Commercial-Scale Facility, and once we have determined each original equipment manufacturer for major pieces of equipment and based on the specification sheets for each piece of equipment, ATC permits for the proposed Commercial-Scale Facility will be provided to MDAQMD for approval. It is expected that the issuance of the ATCs will require that the existing operating permits for the SSF be closed. The ATC permits for the proposed Commercial-Scale Facility must meet National Ambient Air Quality Standards (“NAAQS”) and MDAQMD requirements (Air Resources Board, MDAQMD, and EPA).

There is no reclamation or closure requirement under MDAQMD.

The LRWQCB issued the current WDR in 1988. The WDRs regulate activities in the existing surface impoundments, which were used in the 1990’s to produce CadyCal and are no longer being used. We remain compliant with the permit by complying with the monitoring requirements and submitting quarterly reports. A Final Permanent Closure Plan has been approved by the LRWQCB for closure of the existing impoundments. The closure of the ponds and the 1988 WDRs is pending final sign-off by the LRWQCB. The current proposed Commercial-Scale Facility design includes approximately 37 acres of evaporation ponds for the purpose of removing sodium and calcium from the back end of the processing plant. We will apply for a new or amended WDRs order from LRWQCB for the proposed Commercial-Scale Facility.

There is an existing reclamation and closure requirement approved by LRWQCB. The bond amount to close the ponds is included in the SBC – LUS Financial Assurance Cost Estimate (“FACE”), discussed below. This is currently secured with a partially collateralized surety bond.

The LRWQCB also issued a NONA, verifying that the Project does not require a stormwater permit for approved construction and operations activities. The NONA was issued as the Project is located in a closed basin with no stormwater discharge.

There is no reclamation or bonding requirement associated with the NONA.

SBC-LUS issued the Mining Conditional Use Permit and Reclamation Plan in 1994, based upon the 1990 application and ensuing EIR. The Reclamation Plan was amended, and the permit was modified in 2019 to address changes such as relocation of the processing plant and additional water related infrastructure. Ground use is regulated in accordance with applicable state law. The Mining Conditional Use Permit and Reclamation Plan includes Conditions of Approval for engineering and planning related activities, as well as requirements to avoid impacts to desert tortoises. The permitted production throughput under the Mining Conditional Use Permit is 90,000 short tons of boron oxide or boron oxide equivalent.

We maintain a certificate of deposit with the California State Mining and Reclamation Agency, as administered by SBC-LUS. The FACE is updated annually. The FACE includes demolition of all existing structures, regrading, and revegetation of all disturbance on private lands. This bond also includes plugging and abandonment of all wells located outside the EPA UIC purview.

The BLM issued a ROD in 1994, establishing the EIS boundary. The ROD authorizes mining of borates. The ROD also has requirements for our activities to eliminate adverse impacts to desert tortoises and cultural resources.

Reclamation and land disturbance for BLM is currently included with the FACE on file with the County and is secured with a partially collateralized surety bond. Previously we held certificates of deposit, which were subsequently released since the surety bond was accepted and approved.

The EPA retains primacy for Class 3 solution mining UIC permits in the State of California. The EPA issued the UIC permit for the Project in August 2020. The permit defines the Area of Review (“AOR”) boundary. All subsurface solution mining activities, including monitoring wells and injection wells, are located within the AOR boundary. The EPA approved mining operations in November 2023.

In accordance with the permit conditions, we have installed five upgradient and four downgradient monitoring wells for the initial mining block. As a condition to receive final approval in November 2023, the EPA required modification to the permit and the installation of nine additional water monitoring wells for a total of eighteen monitoring wells. The permit was modified in June 2024, and the nine additional wells were installed in fall 2024.

We installed four Injection/Recovery Wells (“IR Wells”) and subsequently modified the permit to include horizontal wells. In July 2025, two of the IR Wells were converted from vertical wells to horizontal-side tracks where each well extends approximately 1,500 feet laterally. During the quarter ended March 31, 2026, we encountered difficulties with the lateral sections of these wells, and they are no longer accessible. However, while they were operational, we validated technical and operating feasibility of horizontal wells, injection rates, geologic continuity of the main mineralized horizon, a more consistent head grade relative to vertical wells, and validated materials of construction and future completion designs. We expect to submit a final mine plan to the EPA for review following additional wellfield testing and validation.

We have submitted and maintain a fully collateralized surety bond with the EPA for plugging and abandonment of all wells within the EPA AOR boundary.

Additional environmental permitting that will likely be required for the proposed Commercial-Scale Facility includes:

a.

The California Unified Control Act/Agency has primacy over EPA’s Tier II reporting requirements. The Hazardous Material Business Plan has been submitted for construction related activities and will be updated with processing related chemicals that are expected to be utilized to operate the proposed Commercial-Scale Facility. Such updates will require additional approvals.

b.

The current AOR boundary does not include the entirety of Section 36. It is anticipated 5E will request an additional AOR boundary extension to include the Section 36 vested right property.

SSF and Wellfield Update

The SSF is an above ground chemical plant, which commenced operations in April 2024, designed to refine borates extracted from the Project’s in-situ mining operations. The SSF serves as the foundation for the design, engineering, and cost optimization of our proposed Commercial-Scale Facility, and as the source of product for our customer qualification and commercial strategy efforts. The wellfield comprises our injection and recovery wells, through which we inject a weak acid solution into the colemanite ore body, extract the resulting pregnant leach solution, and deliver it to the SSF for processing into boric acid and other boron products. Together, the SSF and wellfield represent our current operating infrastructure and the primary basis for demonstrating the technical and commercial viability of the Project. For a discussion of recent SSF and wellfield activities and accomplishments during fiscal year 2026, refer to the “Our Strategy and Recent Accomplishments” section above.

Updated Preliminary Feasibility Study, Technical Report Summary

In connection with the filing of this Annual Report, and included as Exhibit 96.1, we issued an updated Preliminary Feasibility Study prepared in accordance with Regulation S-K 1300, which focuses on developing Phase 1 (130,000 short ton per annum boric acid plant) of our Fort Cady Project. We believe the PFS demonstrates a superior resource and management’s firm understanding of, and direction for, the business, all of which we believe can help position us to achieve profitability, generate cash flow, and reduce risk.

Due to the current favorable market backdrop and growing importance of critical materials, we continue to focus primarily on further defining our boron reserves, and to work towards developing our proposed Commercial-Scale Facility for the production of borates, calcium chloride and gypsum. A focus on boron extraction and related end markets is aligned with our mission to become a global leader in enabling industries addressing decarbonization, food security, national defense and production of domestic supply and our focus on high-value-in-use materials and applications.

The PFS includes a revised mineral resource estimate inclusive and exclusive of reserves, a mineral reserve statement for boric acid, estimates for capital costs and operating expenses, and a bottoms-up economic analysis of the first commercial phase of the Project. The financial model for the economic analysis includes third-party preliminary market studies and independent pricing forecasts for boric acid, calcium chloride and gypsum.

The PFS included a capital estimate of approximately $367 million, a 15% contingency of approximately $55 million, and owner’s costs of approximately $13 million, for an aggregate capital estimate of approximately $435 million. The capital estimate includes the anticipated costs for a natural gas CHP COGEN facility that will power Phase 1 of the Project. The estimated accuracy range for the capital estimate is ±25%, which is consistent with industry standards for an Association for Advancement of Cost Engineering Class 4 estimate for projects at the PFS stage. Our capital estimate is supported by a comprehensive suite of engineering deliverables, including process flow diagrams, simulation and material balance data, equipment lists, preliminary design documentation, and advanced vendor testing, all of which contribute to a well-substantiated capital cost basis.

The report was prepared by qualified persons (“QP” as defined in S-K 1300) including Company management and third-party independent companies Miocene, Fluor, Geomega, Inc., and Escalante Geological Services, LLC (“Escalante”). All QPs have the necessary experience per Regulation S-K 1300 and material assumptions and information pertaining to the disclosure of our mineral resources, including material assumptions relating to all modifying factors, price estimates, and scientific and technical information, as described in the PFS, and remain current as of the date of this report.

The PFS was based upon converting approximately 17.5% of our total mineral resource and established approximately 5.1 MSTs of boric acid reserves with an average grade of 7.89% (B 2 O 3) and an initial 37.5 year life of mine utilizing an in-situ leaching mining method. Although our PFS focused on Phase 1 of commercial production, we have retained optionality for Phase 2 and Phase 3, at which point full operation could include 450,000 short tons of boric acid.

We will continue to operate the SSF while we stage gate to FEL-3 engineering for Phase 1 of the commercial-scale complex. FEL-3 engineering is expected to provide the necessary estimates to publish a final feasibility study and reach a final investment and construction decision for Phase 1 of the proposed commercial-scale complex during calendar year 2027. Based upon progress to date, we are now targeting to reach initial commercial production from Phase 1 in calendar year 2030, but this target may not be achieved and is contingent upon progressing through FEED engineering by January 2027 and securing the necessary financing to commence construction in January 2028.

Plan of Operations

Upon successful development of the Project, we expect to mine and process colemanite to produce borates, calcium chloride, sodium chloride, and gypsum. The borates produced are planned to be further produced into second, third and fourth boron derivatives. We also continue to evaluate the potential production of lithium carbonate as a possible additional byproduct of the Project. Initially, we expect to derive revenue principally from the sale of boric acid, calcium chloride, and gypsum. As our advanced boron materials strategy develops, we intend to produce revenue from advanced boron materials further enabling decarbonization, energy, food security, and defense applications. Refer to the discussion above under “Our Strategy and Recent Accomplishments” for recent updates on our advanced materials development.

The Project deposit is planned to be mined via ISL mining to recover leached solution from the mineralized horizons, which is a technique that has been utilized for several decades in the production of uranium, salt, bromine, potash and soda ash. The use of in-situ technology for boron extraction was developed at the Project property in the 1980s. In-situ solution mining depends on void spaces, porosity, permeability, ore zone thickness, transmissivity, storage coefficient, piezometric surface, and hydraulic gradient as well as reaction and extraction method efficiencies. There are various ways of developing the wellfield for in-situ leaching, including a “push-pull” mechanism where wells function as both injection and recovery wells; line drive; and multiple spot patterns. We plan to develop the Project utilizing a horizontal well development strategy, and this strategy was incorporated into the assumptions for the PFS. During July 2025, we drilled horizontal sidetracks from two of our existing vertical IR Wells, placing the wellbores in high-grade colemanite zones of the deposit. As described above under “Wellfield,” we subsequently determined that these horizontal sidetracks were no longer accessible; however, while they were operational, we validated certain technical and operating parameters that we expect to inform our future wellfield design.

The recovery of boron from colemanite is currently occurring through ISL mining and boric acid is being produced at the SSF. The in-situ mining method includes injecting a weak hydrochloric acid (“HCl”) solution (containing <5% HCl in substantially recycled water solution with regenerated HCl) through wells drilled into the colemanite ore body. The injected acid remains in the formation for a limited period of time to allow reaction with the alkaline ore body and leach the colemanite ore.

The extracted solution is pumped to the SSF where leach solution is crystallized to produce boric acid. The crystallized boric acid is dried, sized, and bagged as final product. Other boron products are expected to be prepared for market, as required, by end-use customers. Calcium is expected to be recovered from the remaining solution after boric acid processing to produce either gypsum or calcium chloride with the final solution being substantially recycled back into the resource deposit. Within the processing facility, some HCl is regenerated from the gypsum precipitation process as a result of the sulfuric acid acidification of the process recycle stream. The weak HCl solution is combined with recycled water to produce the make-up solution for reinjection into the formation. The process operates a zero liquid discharge evaporator and produces no liquid waste.

Mineral Resource Estimate

Mr. Steven Kerr of Escalante Geological Services, LLC completed an updated resource estimate effective June 30, 2026 (the “June 2026 Estimate”), which incorporated expanded mineral tenure and the exclusion of mineral reserves, as compared to the prior year mineral resource estimate. The June 2026 Estimate was delineated into controlled resources (which includes minerals secured by unpatented lode claims, our fee lands, and the SCE power corridor), and uncontrolled resources (which includes minerals available for mineral lease from the California State Lands Commission). The June 2026 Estimate identified 51.79 MSTs of measured ore, containing 7.71 MSTs of in-situ boric acid (H 3 BO 3), with an average grade of 8.44% (B 2 O 3), and 76.31 MSTs of indicated ore, containing 11.19 MSTs of in-situ boric acid (H 3 BO 3), with an average grade of 8.33% (B 2 O 3). On a combined basis, measured plus indicated mineral resource represent 18.90 MSTs of in-situ boric acid (H 3 BO 3), with an average grade of 8.37% (B 2 O 3). The June 2026 Estimate also identified an aggregate measured plus indicated mineral resource estimate of 208 TSTs of lithium carbonate equivalent (“LCE”), with an average grade of 0.17% LCE. The June 2026 Estimate also identified 3.09 MSTs of inferred ore, containing 0.41 MSTs of in-situ boric acid (H 3 BO 3), with an average grade of 7.66% (B 2 O 3). The June 2026 Estimate also identified an inferred mineral resource estimate of 4 TSTs of LCE, with an average grade of 0.15% LCE. Unless otherwise indicated, average grades for mineral resources presented in this discussion are calculated by weighting the grade of each mineralized bed by its contained product (in-situ boric acid for B₂O₃ grades and lithium carbonate equivalent for LCE grades). Average grades for mineral reserves presented in this Annual Report are weighted by ore tonnage.

Uncontrolled lands included in the June 2026 Estimate identified 22.36 MSTs of measured plus indicated ore, containing 2.45 MSTs of in-situ boric acid (H 3 BO 3), with an average grade of 6.41% (B 2 O 3), and 0.93 MSTs of inferred ore, containing 0.10 MSTs of in-situ boric acid (H 3 BO 3), with an average grade of 6.41% (B 2 O 3). The June 2026 Estimate also identified an aggregate measured plus indicated mineral resource estimate of 44 TSTs of LCE within uncontrolled lands, with an average grade of 0.20% LCE. The June 2026 Estimate also identified an inferred mineral resource estimate of 2 TSTs of LCE, with an average grade of 0.20% LCE in uncontrolled lands.

Mineral Resources

Regulation S-K 1300 defines a “mineral resource” as a concentration or occurrence of material of economic interest in or on the Earth’s crust in such form, grade or quality, and quantity that there are reasonable prospects for economic extraction. A mineral resource is a reasonable estimate of mineralization, taking into account relevant factors such as cut-off grade, likely mining dimensions, location or continuity, that, with the assumed and justifiable technical and economic conditions, is likely to, in whole or in part, become economically extractable. It is not merely an inventory of all mineralization drilled or sampled.

A “measured mineral resource” is that part of a mineral resource for which quantity and grade or quality are estimated on the basis of conclusive geological evidence and sampling. The level of geological certainty associated with a measured mineral resource is sufficient to allow a qualified person to apply modifying factors, as defined in this section, in sufficient detail to support detailed mine planning and final evaluation of the economic viability of the deposit. Because a measured mineral resource has a higher level of confidence than the level of confidence of either an indicated mineral resource or an inferred mineral resource, a measured mineral resource may be converted to a proven mineral reserve or to a probable mineral reserve.

An “indicated mineral resource” is that part of a mineral resource for which quantity and grade or quality are estimated on the basis of adequate geological evidence and sampling. The level of geological certainty associated with an indicated mineral resource is sufficient to allow a qualified person to apply modifying factors in sufficient detail to support mine planning and evaluation of the economic viability of the deposit. Because an indicated mineral resource has a lower level of confidence than the level of confidence of a measured mineral resource, an indicated mineral resource may only be converted to a probable mineral reserve.

An “inferred mineral resource” is that part of a mineral resource for which quantity and grade or quality are estimated on the basis of limited geological evidence and sampling. The level of geological uncertainty associated with an inferred mineral resource is too high to apply relevant technical and economic factors likely to influence the prospects of economic extraction in a manner useful for evaluation of economic viability. Because an inferred mineral resource has the lowest level of geological confidence of all mineral resources, which prevents the application of the modifying factors in a manner useful for evaluation of economic viability, an inferred mineral resource may not be considered when assessing the economic viability of a mining project, and may not be converted to a mineral reserve.

Resource Assumptions

Key assumptions used in the resource estimate include: mineralized horizons exhibit lateral continuity that will support mining using in-situ leaching mining methods, mineralized horizons are not disrupted by structural or stratigraphic features that could limit mining, there is reasonable continuity of colemanite mineralization throughout the deposit, and there is adequate exploration data to support estimation of resources.

Resource Methodology

The database used for resource estimation includes 52 core holes and three rotary holes for a total of 55 bore holes. Thirty of the core holes were completed by Duval between 1979 and 1981. We completed 14 core holes in 2017 and another core hole in 2022. In 2024, we completed three additional rotary holes as observation wells from which chip samples were collected through the mineral horizons for B 2 O 3 and lithium analyses. The cumulative sampled length for the database is approximately 17,848 feet. The Project’s exploration dataset is current as of February 12, 2025. Drilling coordinates in the database are in UTM NAD 83-11, and depths and elevations are reported in meters. Borate is listed as weight percent (%) B 2 O 3 and lithium as ppm. The drilling database contains 5,767 analytical values for B 2 O 3 and 5,402 analytical values for lithium.

Core recovery for the 2017 drilling program ranged from 93% to 100% with an overall average of 97.60%. Physical core recovery records for earlier drilling conducted by Duval and FCMC are not available, but based on missing intervals in the drilling database, core recovery likely exceeded 90% in the core drilling and correlates to the 2017 drilling program. The QP has completed a thorough review and verification of the drilling database and found the database to be sufficient for resource modeling.

The QP developed a gridded geologic model of the Project using Carlson Mining™ software. The mineralization does not correlate to lithological markers as the entire sequence is predominantly lacustrine mudstone. However, detailed examination of the analytical results reveals distinct mineralized horizons. The deposit was delineated based on these patterns of mineralization into four mineralized horizons, two non-mineralized or weakly mineralized interbeds and two non-mineralized horizons bounding the deposit. The grid model was constructed across the deposit area, with a grid cell size of 50 meters by 50 meters. Grids represent the bounding elevation surfaces of key horizons, horizon thicknesses, and analytical grades. Grids representing the bounding surface elevations of the mineral horizon were interpolated through triangulation. Mineral horizon grids for thickness and analytical grades were interpolated using Ordinary Kriging (“OK”) and Inverse Distance Squared (“ID2”) algorithms. Mineralization is spatially defined by a resource boundary using a distance of 200 meters from the last intersection of mineralization in a drill hole and by property boundaries. Grids are masked to the outside of the resource boundary.

Using composites for each mineralized horizon, variography was successful for B 2 O 3 grades for the Major Mineralized Horizon (“MMH”), Intermediate Mineralized Horizon (“IMH”), and the Lower Mineralized Horizon (“LMH”). Variogram modeling was unsuccessful for the Upper Mineralized Horizon (“UMH”) and with lithium in all horizons. Grids representing B 2 O 3 grades for the

MMH, IMH, and LMH were constructed using OK based on the constructed variograms. ID2 interpolation was used with all remaining grade grids using the same spatial limits established with the horizon grids.

Cut-off Grade

The definition of cut-off grade for an in-situ mining operation is the economic point at which a producer would cease operating a particular well, or in the case of a combination of wells, the wellfield, when the variable costs to produce the next unit of production exceed the price that can be achieved in the market for that product. As such, cash costs are established as the basis for a cut-off grade analysis. We commenced mining operations in January 2024 and began operating the SSF in April 2024. The SSF achieved a steady state of operation in the summer of 2024 and optimized mining operations by September 2024. As such, mining data from September and October 2024 have been utilized as the basis of design and further leveraged for the cut-off grade analysis. Using this data set, an in-depth assessment was performed that included an analysis of the cash costs (i.e., the variable cost to produce boric acid) and excluded book costs (i.e., depreciation) as the capital is assumed to have already been invested to build the project such that it can operate.

An in-depth assessment of cut-off grade was undertaken in 2022 and 2023 as mass and energy balances were developed to fundamentally begin to assess economic viability of the Project. Data informing the mass and energy balances included incorporating the results of leaching tests, historical results, mining, and processing costs, as well as commodity pricing, and resulted in a 2.0% cut-off calculation.

The in-depth analysis discussed above incorporated mineralization and at what point economic extraction or boron in solution is no longer viable. The driver of this analysis focuses on three specific ratios derived from the basis of design using mining data from the periods of September and October 2024: calcium to boron, sodium to boron, and magnesium to boron. These three ratios are drivers of various costs, chemical utilizations, and byproduct production rates. For example, calcium to boron impacts sulfuric acid utilization and gypsum production compared to boric acid production. Additionally, magnesium to boron impacts lime utilization and metal salt waste production compared to boric acid production. Lastly, sodium to boron impacts HCl utilization and sodium chloride production compared to boric acid production.

The PFS incorporated the above methodology and other key assumptions that are in the financial model detailed in Section 19 of the PFS (refer to Exhibit 96.1 of this Annual Report). The sales price for boric acid has increased over the past several years and was tracking in a range of $950 to $1,080 per short ton free on board (“FOB”) as of June 2026 per Fastmarkets boric acid, technical grade, granular fca UW West Coast index, and the PFS includes an assumption of $1,248 per short ton FOB when production first commences based on a preliminary market study prepared by an independent third-party. Sales prices for calcium chloride and gypsum in the PFS were similarly based upon a preliminary market study and forecasts prepared by the same independent third-party. The result of this exercise is a 2.0% financially viable driven grade cut-off, where the costs are near the forecasted price for boric acid.

Fort Cady Mineral Resource Estimate as of June 30, 2026, exclusive of mineral reserves

Results of the mineral resource estimation are shown in the table below, based on resource classification of the Project. The resource estimate contains a combined 128.10 MSTs of measured plus indicated ore under mineral control, containing 18.90 MSTs of in-situ boric acid (H 3 BO 3), with an average grade of 8.37% (B 2 O 3), and 208 TSTs of LCE, with an average grade of 0.17% LCE. The resource estimate was prepared using a 2.0% cut-off grade for B 2 O 3 and no cut-off grade for lithium. The sales price for boric acid has increased over the past several years and was tracking in a range of $950 to $1,080 per short ton FOB as of June 2026 per Fastmarkets boric acid, technical grade, granular fca US West Coast index. Our PFS estimates the FOB prices for boric acid, calcium chloride and gypsum to be $1,248, $174 and $33 per short ton, respectively, in the first year of production, based upon a preliminary market study prepared by an independent third-party, as discussed in further detail of Sections 16 and 19.3.1 of our PFS filed as Exhibit 96.1 to this Annual Report. As of June 2026, the price of calcium chloride and gypsum were at approximate values forecasted in the PFS. The mineral resource estimate also identified 3.09 MSTs of inferred ore under mineral control, containing 0.41 MSTs of in-situ boric acid (H 3 BO 3), with an average grade of 7.66% (B 2 O 3), and 4 TSTs of LCE, with an average grade of 0.15% LCE. The reference point for the resource in the PFS is in-situ prior to mining losses and processing losses.

Table prepared using a 2.0% B 2 O 3 cut-off grade and no lithium cut-off grade.

(1)

“UMH” is Upper Mineralized Horizon, “MMH” is Major Mineralized Horizon, “IMH” is Intermediate Mineralized Horizon, and “LMH” is Lower Mineralized Horizon.

(2)

Grades shown in the table are per-bed in-situ grades. Average grades for aggregated classifications presented in the accompanying narrative are weighted by contained product rather than by ore tonnage, as described above.

Commodity Pricing Assumptions

Our PFS includes an economic analysis, and we obtained an independent preliminary market study for boric acid, calcium chloride and gypsum. The preliminary market study was based on 15 years of historical data and include an assessment of future supply and demand analysis as well as forecasted future price assumptions, as further detailed in Sections 16 and 19.3.1 of our PFS, which is incorporated by reference as Exhibit 96.1 of this Annual Report. Our PFS estimates the price for boric acid to be $1,248 per short ton in the initial year of commercial production, escalating to $1,364 per short ton in year 5 due to demand outpacing supply of boric acid, and then held flat when supply and demand for boric acid are expected to normalize. Our PFS estimates the price for calcium chloride and gypsum to be $174 and $33 per short ton, respectively, in the initial year of commercial production, with such prices held flat throughout the model. The price utilized in the financial model for gypsum and calcium chloride is the real price as of June 2025 as provided by the independent preliminary market study. Per the independent preliminary market study, the sales price for boric acid has increased over the past several years. The price of boric acid was tracking in a range of $950 to $1,080 per short ton FOB in the spot market as of June 2026 per Fastmarkets boric acid, technical grade, granular fca US West Coast index, with variations driven by differing jurisdictions in the spot market. Refer to the tables below for a summary of the prices utilized in our economic analysis included in our PFS.

The PFS was prepared based primarily on information available at the time of preparation, is subject to assumptions, conditions and is qualified by various limitations. The foregoing summary description of the PFS is qualified in its entirety by reference to the full PFS, which is included as Exhibit 96.1 to this Annual Report.

Internal Controls Disclosure for Mineral Resource and Mineral Reserve Estimation

Between September 2017 and October 2017, 14 holes for a total of 23,111 feet were completed as part of a confirmatory resource drilling program. Assay results from all 14 drill holes were used in the mineral resource estimate. There are 2,113 samples from the 2017 drilling program representing 1,713 feet of core. In conjunction with the 2017 drilling program, 29 historical drill holes completed by Duval and four holes completed by FCMC were in the mineral resource estimate. There are 3,672 samples from the historic drilling representing a cumulative total of 10,831 feet of core.

The PFS indicates that the quality assurance and quality control (“QA/QC”) procedures for the Duval and FCMC drill holes are unknown, though the work products compiled during these historic drilling campaigns, suggests they were carried out by competent geologists following procedures considered standard practice at those times. Discussions held with the exploration geologist for Duval at the time of drilling and sampling indicate that Duval had internal QA/QC procedures in place to help confirm the accuracy of the assay results. Geochemical analyses were carried out using X-Ray Fluorescence Spectrometry (“XRF”). XRF results were reportedly checked against logging and assay data.

For the database of drill holes, entire core hole sequences were sampled and dispatched by commercial carrier to the Saskatchewan Research Council (“SRC”) for geochemical analysis. As part of the QA/QC procedures, internationally recognized standards, blanks and duplicates were inserted into the sample batches prior to submitting to SRC. SRC has been accredited by the Standards Council of Canada and conforms with the requirements of ISO/IEC 17025.2005. Upon receipt of samples, SRC completed an inventory of samples received, completing the chain of custody documentation, and providing a ledger system tracking samples received and steps in process for sample preparation and analysis. Core samples and chip samples were dried in their original sample bags, then jaw crushed. A subsample was split out using a sample riffler. The subsample was then pulverized with a jaw and ring grinding mill. The grinding mill was cleaned between each sample using steel wool and compressed air or by silica sand. The resulting pulp sample was then transferred to a barcode labeled plastic vial for analysis. All samples underwent a multi-element Inductively Coupled Plasma Optical Emission Spectroscopy (“ICP-OES”), using a multi-acid digestion for a range of elements. Boron was also analyzed by ICP-OES but underwent a separate digestion where an aliquot of the sample was fused in a mixture of NaO 2/NaCO 3 in a muffle oven, then dissolved in deionized water, prior to analysis. Major oxides were reported in weight percent. Minor, trace, and rare earth elements were reported in ppm. The detection limit for boron was 2 ppm and 1 ppm for lithium.

For the database of drill holes, a total of 2,253 core samples and 441 control samples were submitted for multi-element analysis to SRC. We submitted control samples, in the form of certified standards, blanks and coarse duplicates (bags with sample identification supplied for SRC to make duplicate samples). In addition to these control samples, SRC also submitted their own internal control samples in the form of standards and pulp duplicates. Certified standards, prepared by the National Institute of Standards and Technology, were submitted as part of our QA/QC procedures. No two standards in any single batch submission were more than two standard deviations from the analyzed mean, implying an acceptable level of precision of SRC instrumentation. SRC assayed two different standards, for its own QA/QC protocol and the QP found that the analytical precision for analysis of both standards was reasonable, with no two standards in any single batch submission being more than two standard deviations from the analyzed mean.

Blank samples inserted consisting of non-mineralized marble. One hundred and thirty-five blank samples were submitted, all of which had assay results of less than 73 ppm boron. The level of boron detected in the blanks was likely sourced from pharmaceutical (borosilicate) glass used during sample digestion. These boron concentrations are considered immaterial in relation to the boron levels detected in the colemanite mineralization and do not appear to represent carryover contamination from sample preparation. Lithium levels in the blank samples were also at acceptable levels with the majority of assays less than 15 ppm lithium. The four highest lithium levels in the blanks immediately followed samples that contained relatively high lithium concentrations. Overall, the concentration of the primary elements of interest (boron and lithium) in the blank samples were at levels considered to be acceptable, implying a reasonable performance for sample preparation.

A total of 136 duplicate samples were submitted to the SRC. SRC composed coarse duplicate samples using a Boyd rotary splitter. There was a good correlation between original and duplicate samples with a reasonable level of precision maintained in the results.

In addition to the sampling and analytical procedures described above, we maintain internal controls for reviewing and documenting the information supporting our mineral resource and mineral reserve estimates, the methods used to prepare them and the validity of the resulting estimates. Drill hole, survey and assay data are maintained in a central database, and the QPs perform data entry and validation checks on that database before it is used to prepare the estimates. The information used to compile our mineral resource and mineral reserve estimates is prepared and certified by the QPs identified above. Our Chief Executive Officer is primarily responsible for reviewing the work of the QPs who prepare those estimates, and our Chief Executive Officer evaluates (together with those QPs) the reasonableness of the criteria, assumptions and modifying factors used in the estimates. Calculations performed using those criteria are reviewed and validated by the QPs.

Mineral resource and mineral reserve estimates are, by their nature, estimates and are subject to a comprehensive range of risks and uncertainties. These include the geological complexity and continuity of the deposit; the density, spacing and reliability of the drilling and sampling data on which the estimates are based, including our reliance in part on historic drill holes completed by Duval and FCMC for which QA/QC procedures are unknown; the interpretation, modeling and extrapolation of that data; the reliability of metallurgical testwork and recovery assumptions; the accuracy of estimated capital and operating costs; the selection of cut-off grade and commodity price assumptions; the availability and continued effectiveness of mineral tenure, water rights, permits and infrastructure; and changes in the mine plan, technology, regulation or macroeconomic conditions. Because our mineral reserve estimate is derived from the mine plan and economic analysis in the PFS, which is a preliminary feasibility study, it is subject to greater uncertainty than an estimate supported by a final feasibility study. Actual quantities of borates and other minerals recovered, and the costs of recovering them, may differ materially from these estimates. For additional information, please see the risks described under the heading “Part I, Item 1A. Risk Factors” in this Annual Report.

Comparison of Mineral Resource Estimates to Prior Year

The prior year mineral resource estimate, which was estimated as of March 10, 2025 and remained valid as of June 30, 2025, reported aggregate measured, indicated and inferred mineral resources of 3.37, 14.18 and 0.55 MSTs of in-situ boric acid (H 3 BO 3), respectively. The mineral resource estimate included as Exhibit 96.1 to this Annual Report and summarized above, was estimated as of June 30, 2026, reported aggregate measured, indicated and inferred mineral resources of 7.84, 13.51, and 0.52 MSTs of in-situ boric acid (H 3 BO 3), respectively. This represents a 22% increase in combined measured and indicated resource, which is comprised of a 133% increase in measured resource, and a 5% decrease in indicated resource. Inferred resource decreased 7% compared to the prior year. These year-over-year changes are ascribed to; (i) approximately 5.1 MSTs of proven and probable mineral reserves being excluded from the current year mineral resource estimate versus such amount being included in the prior year estimate, and (ii) the expansion of our mineral tenure between estimates as the result of the filing of additional lode claims.

Mineral Reserve Estimate

Miocene has completed a mineral reserve estimate for the Project. The mineral reserve estimate was developed based upon the detailed mine plan included in Section 13 of our PFS and the mineral resource estimate. Prior to August 2025, when we published the original pre-feasibility study for the Project, we had not yet established mineral reserves and therefore had not disclosed reserve estimates. Reserves point of reference is in-situ with a 2.0% cutoff grade established based on the analysis performed with the mineral resources cut-off grade. Our EPA UIC permit subdivides the mineralized deposit into three blocks for development. Block 1 comprises the northwestern third of the orebody, Block 2 occupies the central portion of the orebody, and Block 3 comprises the southeastern third of the orebody. The SSF currently operates in Block 2 and Block 2 is permitted for mining with sufficient resources on fee-based lands and within the power corridor operated by SCE to convert resources to reserves on an economic basis, which provides for a 37.5 year life of mine. To convert additional resources to reserves, Block 1 and Block 3 would need to be authorized by the EPA and a mine plan devised that includes this mineral tenure.

For economic modeling, a mine plan was designed where recovery and flow rates are sufficient to feed the chemical plant where PLS is converted to a finished refined borate product available for sale. Production output is within permitted parameters with forecasted revenue from borate sales based on a pricing forecast based on the aforementioned third-party preliminary market study.

The mine plan and wellfield optimization were based on third-party engineering work that incorporated months of actual wellfield data from the SSF into the design and included a bottoms-up capital estimate. The capital estimate was derived by Fluor for the inside and outside battery limits above ground and a total capital estimate was derived and incorporated into the economic analysis. The operating costs were derived from material and energy balances provided by Fluor as well as a bottoms-up labor build for human capital requirements. The revenue and cost inputs for the economic model were on a real basis.

The reserve estimate identified 2.57 MSTs of proven boric acid (H 3 BO 3) reserves with an average grade of 7.92% B 2 O 3, and 2.48 MSTs of probable boric (H 3 BO 3) reserves with an average grade of 7.87% B 2 O 3, each derived using a 2.0% cut-off grade, consistent with the cut-off grade for the mineral resource estimate. The mineral reserve estimate was incorporated into our PFS, which is incorporated by reference to Exhibit 96.1 to this Annual Report.

Mineral Reserves

Regulation S-K 1300 defines a “proven mineral reserve” as the economically mineable part of a measured mineral resource and can only result from conversion of a measured mineral resource.

A “probable mineral reserve” is the economically mineable part of an indicated and, in some cases, a measured mineral resource.

Reserve Assumptions

Assumptions utilized for the reserve estimate were consistent with the assumptions utilized for the resource estimate, except that only measured and indicated resource included in the mine plan from fee-based lands and the power corridor operated by SCE were included in the resource base (representing a portion of our fee-based lands and the power corridor). The economic assessment that supports the recognition of reserves was based on a 130,000 short ton per year boric acid production plant, a capital cost estimate for Phase 1 of the Project of approximately $435 million, in-situ leaching mining operation delivering 10.2% boric acid in solution (head grade), by weight, to an above ground processing plant; the aforementioned commodity price assumptions; cash operating costs of approximately $563 per ton of boric acid produced and a 7% discount rate. Additional assumptions included performing a tradeoff analysis based on actual vertical well performance relative to expected horizontal well performance whereby horizontal well performance is expected to outperform vertical wells, the chemical plant is designed to yield 95.1% boric acid yield, leaching efficiency is assumed to be 81.9% based on leach testing, and mining efficiency was 95% based on the Company’s July 2025 horizontal drilling program.

The reserve estimate is subject to potential change based on changes to the forward-looking cost and revenue assumptions. It is assumed that we will produce and sell borates to customers once the proposed Commercial-Scale Facility is constructed, commissioned, and in operation. Full extraction of this reserve is dependent upon the modification of the Company’s UIC permit to include the final mine plan. We obtained a minor modification and authorization to drill the horizontal and sidetrack program in July 2025, and it is our expectation that we will be successful in modifying the UIC permit. The evaporation ponds incorporated into the design of the proposed Commercial-Scale Facility and placed on our fee-based land require a WDR with the LRWQCB, and we expect to obtain the WDR for the evaporation ponds to remove calcium and sodium.

We do not believe that there are other existing environmental, permitting, legal, socio-economic, marketing, political, or other factors that might materially affect the in-situ mineral reserve estimate.

Fort Cady Mineral Reserve Estimate as of June 30, 2026

Comparison of Mineral Reserve Estimates to Prior Year

We did not have mineral reserves as of June 30, 2025. Our initial mineral reserve estimate for the Project was established in the Preliminary Feasibility Study published in August 2025, with an effective date of August 4, 2025, subsequent to our fiscal year ended June 30, 2025, and was first disclosed in our Annual Report on Form 10-K for the fiscal year ended June 30, 2025. Accordingly, the mineral reserve estimate, effective June 30, 2026 and summarized above, represents our first mineral reserve estimate as of a fiscal year end, and no comparison to a prior fiscal year-end mineral reserve estimate is presented.

As compared to the initial mineral reserve estimate effective August 4, 2025, total proven and probable mineral reserves decreased approximately 5%, from 5.34 MSTs to 5.05 MSTs of boric acid (H₃BO₃), and the initial life of mine decreased from 39.5 years to 37.5 years. Within the total, proven mineral reserves increased from 1.35 MSTs to 2.57 MSTs and probable mineral reserves decreased from 3.98 MSTs to 2.48 MSTs, and the average grade of total mineral reserves decreased from 8.03% to 7.89% (B₂O₃). These changes are ascribed to: (i) the June 2026 Estimate, in which the reclassification of certain indicated mineral resources to measured mineral resources within the mine plan area resulted in a corresponding conversion of probable mineral reserves to proven mineral reserves; and (ii) further refining and geologic modeling of the mine plan wellfield, which reduced the recoverable mineralized volume within the mine plan by approximately 5%. The decrease in the initial life of mine is proportional to the decrease in total mineral reserves, as the assumed annual production rate of the proposed Commercial-Scale Facility is unchanged. Key modifying factors were unchanged between the two estimates, including the 2.0% B₂O₃ cut-off grade, leaching efficiency of 81.9%, mining efficiency of 95%, boric acid plant yield of 95.1%, and the aggregate capital estimate of approximately $435 million. No adjustment for depletion was made, as production from the SSF during fiscal year 2026 was de minimis relative to total mineral reserves.

Available Information

We make available free of charge on our website, www.5eadvancedmaterials.com, our annual reports on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K and amendments to those reports filed or furnished pursuant to the Exchange Act, as soon as reasonably practicable after we electronically file such information with, or furnish it to, the SEC. These documents are also available on the SEC’s website atwww.sec.gov. The information on our website is not, and shall not be deemed to be, a part of this Annual Report or incorporated into any of our other filings with the SEC.