Guardian Metal Resources Plc press release

Guardian Metal Resources PLC Announces Pilot Mountain Pre-Feasibility Study Results

2026-06-30

OTC - OTC Markets · United Kingdom · Technical Studies

Positive Pre-Feasibility Study Results for the Pilot Mountain Tungsten Project

PFS Completion marksa critical step toward restoring domestically mined tungsten production in support of the U.S. defense industrial base and national security priorities

At Base Case, Study Shows After-Tax NPV of US$660.3M and IRR of 59.6%

LONDON, UK / ACCESS Newswire/ June 30, 2026 / Guardian Metal Resources plc (NYSE.A:GMTL)(LON:GMET)(OTCQB:GMTLF), a strategic exploration company focused on tungsten in Nevada, USA, is pleased to announce the results of the Pre-Feasibility Study ("PFS" or the "Study") for the Pilot Mountain tungsten project ("Pilot Mountain" or the "Project"). The completion of the PFS marks a critical step in the Company's path towards the potential development of the first new United States ("U.S.") based tungsten mining operation in over a decade.

The Study results indicate that utilizing a conventional open-pit mining method and base case tungsten pricing*, the Project is planned to produce 15,916 tonnes of WO3over an 8-year mine life, generating after-tax free cash flow of US$1.058 billion, with a capital payback period of 1 year from first commercial production. On an after-tax basis at base case tungsten pricing*, this translates to a net present value ("NPV8") of US$660.3 million at an 8% discount rate and an internal rate of return ("IRR") of 59.6%. At the 12 June 2026 tungsten spot price, the Project would generate after-tax free cash flow of US$2.088 billion, with an IRR of 101.6%, an NPV8of US$1.366 billion and a capital payback of 6 months from first commercial production.

The PFS was completed in accordance with S-K 1300 standards by a team of U.S.-based specialist firms, led by Samuel Engineering, Inc. of Denver, Colorado and RESPEC Company LLC ("RESPEC") of Reno, Nevada. The PFS includes an updated Mineral Resource Estimate ("MRE") covering two Project zones, Garnet and Desert Scheelite, as well a Mineral Reserve Statement ("MRS") for the Project. The supporting technical analyses relating to the updated MRE and MRS will be included in a S-K 1300 Technical Report Summary currently being prepared by the Company.

The Pilot Mountain PFS was made possible by a U.S. Department of War $6.2M Defense Production Act (DPA) Title III investment in Guardian Metal's wholly-owned subsidiary, Golden Metal Resources (USA) LLC in July 2025. The Company sincerely thanks the Assistant Secretary of War for Industrial Base Policy, the Honorable Michael P. Cadenazzi, who oversees the Department's execution of its DPA authorities, for their valued support of this milestone study, which marks a critical step toward restoring domestic tungsten mine production in support of the nation's defense industrial base and national security priorities.

Currency values are stated in U.S. dollars and are presented on a 100% project basis. All tonnages are stated in metric tonnes.

_*Base case utilizes a tungsten price of US$197,300 per tonne of WO3, representing a ~35% discount to the mid-price for ammonium paratungstate ("APT") as quoted by Fastmarkets MB-W-0001 of US$304,000 per tonne of WO3as of 12 June 2026. The mid-price as of 26 June 2026 was US$307,500 per tonne of WO3. All prices are for APT with the study assuming a payable factor of 82% for tungsten concentrate._

Oliver Friesen, Chief Executive Officer of Guardian Metal, commented:

"_We are delivering this Study at an inflection point: we believe that the global tungsten market is undergoing an unprecedented structural reset, and the world is waking up to the immense importance of securing reliable, home-grown critical mineral supply. The importance of tungsten for defense, technology, aerospace, and national security has never been more apparent. We believe that Pilot Mountain is the only tungsten Project in the United States with a recently completed S-K 1300 compliant PFS, positioning it as a unique opportunity for near-term U.S. mined tungsten production._

"Against this backdrop, the Pilot Mountain PFS supports the Project's development potential to support U.S. critical mineral and defense independence. We believe this firmly establishes the Project as one of the more compelling tungsten development opportunities in the Western world. The Study demonstrates robust economics using conservative pricing assumptions, with considerable upside at current tungsten prices and from the Project's exploration potential.

"The completed PFS is a testament to years of diligent work by our fantastic operations and development team, and gives us and our stakeholders great confidence as we advance the Project through further engineering, permitting and development toward a future construction decision. We look forward to sharing further updates as we progress toward establishing the first new domestically mined U.S. tungsten operation in over a decade, with production targeted for Q4 2028."

Marc Leduc, P.Eng., Operations Manager of Guardian Metal, commented:

"_This PFS represents the culmination of years of detailed technical work, and I am very proud of what our team has delivered. Tungsten is a metal critically important to U.S. defense, national security and reindustrialization, yet there has been no domestic production in the country for over a decade. Pilot Mountain is a high-margin Project that is uniquely positioned to fill a critical gap in the U.S. tungsten supply chain._

"We are particularly encouraged by the simplicity of the Project. We are proposing the use of conventional mining and processing methods throughout, producing what we believe will be a high-quality concentrate capable of being processed entirely within the U.S.

"The Study outlines a robust operation with a payback period of one year. Beyond the current resource base, we believe there is meaningful exploration upside across a number of the Project's other target areas, including but not limited to, the Tremor Zone, Gunmetal, and Good Hope. We look forward to continuing to advance those targets alongside the important permitting and development work progressing on the Project's Desert Scheelite and Garnet deposits. We believe that we are well positioned to file our Mine Plan of Operations in the near-term as we advance through the National Environmental Policy Act permitting process."

PFS Highlights:

Economics, Pricing and Capex

| • | After-tax NPV8of US$660.3 million and Project IRR of 59.6%, with a capital payback period of 1 year generating after-tax free cash flow of US$1.058 billion*. | | • | Expected low initial Project capital expenditure ("capex") of US$288.7 million, with sustaining capital of US$33.9 million and closure costs of US$22.3 million. Capex includes 15.7% contingency (US$39.1 million) and US$34.3 million of preproduction mining. | | • | In its first full year of operations, the Project is modeled to generate US$348 million in Earnings Before Interest, Taxes, Depreciation, and Amortization ("EBITDA") at the base case*. | | • | As of the 12 June 2026 tungsten spot price of US$304,000 per tonne, first year EBITDA is modeled to increase to US$569 million, representing an uplift of approximately 64% from the EBITDA base case price. | | • | Also at the 12 June 2026 tungsten spot price, the Project generates after-tax free cash flow of US$2.088 billion with a 101.6% IRR and NPV8of US$1.366 billion and has a capital payback period of 6 months from first commercial production. | | • | Expected adjusted operating cost of US$54,622 per tonne of WO3in concentrate (including royalties, transportation, refining along with zinc and silver credits), with a targeted concentrate grade of 60% WO3. |

_*Base case utilizes a tungsten price of US$197,300 per tonne of WO3, representing a ~35% discount to the mid-price for APT as quoted by Fastmarkets MB-W-0001 of US$304,000 per tonne of WO3as of 12 June 2026. The mid-price as of 26 June 2026 was US$307,500 per tonne of WO3. All prices are for APT with the study assuming a payable factor of 82% for tungsten concentrate._

Resource, Reserve and Production

| • | Mineral Resources increased to 21,600 tonnes of WO3Indicated, with Probable Mineral Reserves of 20,275 tonnes of WO3(11,822,000 tonnes @ 0.171% WO3). | | • | The operation plan calls for the construction of a 4,000 tonne per day processing plant using flotation recovery methods to produce a tungsten concentrate. | | • | The ore will be mined from a conventional open-pit mine using 92-tonne haul trucks and large wheel loaders. | | • | The operation plan calls for the construction of a conventional lined tailings storage facility which will meet the U.S. and international standards for tailings management, including the Nevada Administrative Code requirements and Canadian Dam Association guidelines. |

Timelines, Life of Mine, Permitting and Utilities

| • | The Project timelines contemplate an open-pit mining operation with first ore through the mill in Q4 2028, with initial commissioning tonnes marking the start of processing operations. | | • | Expected initial 8-year Life of Mine ("LoM") producing 15,916 tonnes of recovered WO3, with significant opportunity to extend through ongoing exploration at the Tremor Zone, Gunmetal, Good Hope, plus other unnamed target areas across the Project. | | • | Work completed for the PFS supports the near-term filing of the Mine Plan of Operations ("POO") with the Bureau of Land Management as part of federal National Environmental Policy Act ("NEPA") permitting process. |

Investor Presentation:

As previously announced, Guardian Metal will host a live investor presentation via 6ix on 01 July 2026 at 11:00 ET / 16:00 BST to discuss the PFS results and provide an update on the Company's outlook, including next steps for the Pilot Mountain Project.

The presentation is open to all existing and potential shareholders. Questions may be submitted ahead of the event via the registration form or at any time during the event.

Investors can sign up to 6ix for free and register for Guardian Metal's presentation here: https://6ix.com/event/guardian-metal-resources-presents-pilot-mountain-pfs

PFS Summary Results with Price Sensitivities:

| Item (all after tax) | NPV8 | IRR | After tax

Cash Flow | Payback | | (US$M) | (%) | (US$M) | (years) | | | Base CaseUS$197,300/t WO3 | $660 | 59.6% | $1,058 | 1.00 | | SpotUS$304,000/t WO31 | $1,366 | 101.6% | $2,088 | 0.51 | | Base -20%US$157,840/t WO3 | $395 | 41.3% | $671 | 1.31 | | Base +20%US$236,760/t WO3 | $922 | 76.0% | $1,440 | 0.71 |

Notes:

1. APT mid-price as of 12 June 2026 as quoted by Fastmarkets MB-W-0001. Latest price as of 26 June 2026 was US$307,500/t.

Further Details:

The following information is derived from the PFS. The PFS reflects a pre-feasibility level assessment of the Project, with the accuracy being plus 20% and minus 15% and is based on the assumptions and parameters described herein. References to "will" or "expected" reflect the planned development scenario, subject to a positive construction decision and successful Project financing.

The PFS envisages initial capital expenditure of US$288.7 million to construct a fully integrated mine, mill complex and associated infrastructure, with a mill feed capacity of 1.4 million tonnes per annum. The operation is designed to produce ~2,000 tonnes of WO₃ in concentrate per annum, with the targeted concentrate grade of greater than 60% WO₃ over the life of mine.

Adjusted operating costs are projected at US$54,622 per tonne of WO₃ contained in concentrate; AISC of US$58,151 per tonne of WO₃ contained in concentrate.

The economic analysis presented in the PFS is based on the assumptions and parameters used in the Study and should be read together with the qualifications, assumptions, and risk factors described elsewhere in this announcement.

The Desert Scheelite and Garnet tungsten deposits are located approximately 2 kilometers apart within a large land package hosting multiple areas of tungsten mineralization. Known tungsten intercepts proximal to the current resource areas provide meaningful potential for further resource expansion.

The PFS estimates first production in late 2028, subject to approval of the POO and a NEPA analysis in mid-2027. The Study utilizes conventional open-pit mining and processing methods, with mine design incorporating environmental protection measures across all phases of construction, operations, and closure. Grid power connection is anticipated via a potential self-build powerline option, with water supply to be sourced from wells, subject to receipt of the required water rights.

Combined production from two concurrent open pits is estimated at 15,916 tonnes of WO₃ in concentrate over the mine life, with a life-of-mine stripping ratio of 12.6, a head grade of 0.171% WO₃, and tungsten recovery from milling and flotation estimated at 78.5%. Mining will utilize 92-tonne haul trucks, with both contractor and owner fleet options evaluated in the PFS. The base case assumes a contractor mining model with an owner's team management structure.

Initial mining of the Desert Scheelite pit will facilitate construction of a modern, zero discharge lined tailings storage facility with a rock embankment. Processing infrastructure will comprise primary and secondary crushing, a two-stage grinding circuit, and a flotation recovery plant. Tungsten will be recovered using an industry-standard fatty acid flotation circuit, with sulfide minerals, including silver, recovered ahead of the tungsten recovery stage. Silver will be produced as part of a base metal concentrate and marketed separately from the primary tungsten product.

PFS Detailed Technical Results:

| | | Desert Scheelite | Garnet Tungsten | Total Pilot Mountain | | Study Production Statistics | Units | Mine | Mine | Project | | Total Ore Mined | million tonnes | 9.738 | 2.085 | 11.822 | | Total Material Mined | million tonnes | 144.013 | 16.337 | 160.350 | | Stripping Ratio | waste: ore | 13.8:1 | 6.8:1 | 12.6:1 | | Processing Rate | tonnes per day | | | 4,000 | | Tungsten Head Grade | % | 0.182 | 0.120 | 0.171 | | Silver Head Grade | Ag g/t | 10.68 | 2.78 | 9.28 | | Contained Tungsten | Tonnes WO3 | 17,768 | 2,507 | 20,275 | | Contained Silver | kOz | 3,343 | 186 | 3,529 | | Tungsten Recovery | % | 78.5% | 78.5% | 78.5% | | Silver Recovery | % | 60% | 60% | 60% | | Total Recoverable Tungsten 1 | Tonnes WO3 | 13,948 | 1,968 | 15,916 | | Total Recoverable Silver | kOz | 2,006 | 112 | 2,117 | | Average Annual Tungsten Production | Tonnes WO3 | 1,744 | 246 | 1,990 | | Average Annual Silver Production 2 | kOz | 251 | 14 | 265 | | Capital | | | | | | Initial Capital | US$ million | | | $288.7 | | Sustaining Capital | US$ million | | | $33.9 | | Life of Mine Capital | US$ million | | | 322.6 | | Contingency (included) | US$ million | | | $39.1 | | Contingency (included) | % | | | 15.7% | | Operating Costs | | | | | | Adjusted Operating Cost per Tonne of Ore 3 | US$/t ore | | | $73.54 | | Mining | US$/t ore | | | $48.16 | | Processing | US$/t ore | | | $24.86 | | G&A | US$/t ore | | | $6.23 | | Other 4 | US$/t ore | | | $(5.71) | | Adjusted Operating Cost per tonne of WO33 | US$/t WO3net of by-products | | | $54,622 | | AISC per Tonne of WO35 | US$/t WO3net of by-products | | | $58,151 | | Mine Life (LoM) | years | | | 8 | | Project Economics6

Base Case Pricing | | | | | | Post-tax NPV (8%) | US$ million | | | $660.3 | | Pre-tax NPV (8%) | US$ million | | | $856.7 | | Post-tax NPV (10%) | US$ million | | | $589.6 | | Pre-tax NPV (10%) | US$ million | | | $767.5 | | Post-tax NPV (15%) | US$ million | | | $446.6 | | Pre-tax NPV (15%) | US$ million | | | $587.4 | | Post-tax IRR | % | | | 59.6% | | Pre-tax IRR | % | | | 67.8% | | Payback Period | years | | | 1.00 |

Notes:

1. WO3calculations are made assuming a saleable good quality tungsten concentrate at >50% WO3concentrate grade for the U.S. market.

2. Silver production is averaged over the Desert Scheelite mine life only.

3. Adjusted Operating Costs Include: On-site mining, processing and general and administrative expenses ("G&A"), royalties and production/excise taxes, permitting and community cost related to current operations, third party smelting, refining and transport costs, stockpiles and inventory write-downs, site-based non-cash remuneration, and by-product credits.

4. Other category includes royalties, transport, production/excise taxes, refining, and by-product credit.

5. AISC includes: Adjusted Operating Costs (above) plus closure costs, and sustaining capital.

6. Project economics are presented for 100% of the project.

[](https://app.accessnewswire.com/imagelibrary/ef8a15b2-cd1d-47aa-8f95-c3cbe1212d00/1184421/image20260630012549e5shiu.png)

Figure 1: PFS Production Profile (Produced WO3Contained in Concentrate)

[](https://app.accessnewswire.com/imagelibrary/fd1777a0-6349-437f-b48f-7508767d1f1f/1184421/image202606300125497pen17.png)

Figure 2: PFS Post-tax Annual and Cumulative Cashflow Profile (grey line cumulative after tax cashflow - right axis)

[](https://app.accessnewswire.com/imagelibrary/13a277d4-d595-46c9-a3eb-8bf1742b2cd4/1184421/image20260630012549d3fljo.png)

Figure 3: Project Sensitivity Analysis (Post-tax Base case NPV8with 10% Sensitivities)

[](https://app.accessnewswire.com/imagelibrary/10ea3f47-bcbf-4882-8e09-bc20014b4723/1184421/image20260630012549eka72v.png)

Figure 4: Project Sensitivity Analysis (Post-tax Base Case IRR with 10% Sensitivities)

EBITDA Calculation at Base Case Price

| Metric | Unit | US$ | | Production | | | | Sold WO3 | tonnes | 15,916 | | Sold Zn | tonnes | 20,037 | | Sold Ag | ounces | 2,117,414 | | | | | | Revenue | | | | Total Gross Revenue | $000 | 2,702,949 | | Total Deductions | $000 | (6,335) | | Total Receipts less deductions | $000 | 2,696,614 | | Private Royalty (2%) | $000 | (54,059) | | Total Net Revenues | $000 | 2,642,555 | | | | | | Project Operating Costs | | | | Mining Cost | $000 | (569,318) | | Processing Cost | $000 | (293,902) | | SG&A Cost | $000 | (73,282) | | Total Operating Costs | $000 | (936,902) | | | | | | Project Capital Costs | | | | Project Development Capital | $000 | (288,701) | | Sustaining Capital | $000 | (33,929) | | Closure | $000 | (22,250) | | Total Capital Cost and Closure | $000 | (344,880) | | | | | | EBITDA, Capital, Tax and Cashflow | | | | EBITDA | $000 | 1,705,654 | | EBITDA-Capital | $000 | 1,360,773 | | Total Taxes | $000 | (302,684) | | After Tax Total Cashflow | $000 | 1,058,090 |

The Mineral Reserve and Mineral Resource estimates summarized below are derived from the PFS. The supporting technical analyses, assumptions, and disclosures relating to such estimates are expected to be included in a forthcoming Technical Report Summary being prepared in accordance with S-K 1300.

Pilot Mountain Project Mineral Reserve Statement:

Probable Reserves total 11.8 million tonnes containing 20,275 tonnes of WO3and 3.5 million ounces silver as detailed below:

| | Average Grade | Contained Metal | | | | | | | | Pit | Classif-ication | k Tonnes | WO3% | Ag g/t | Zn % | WO3t | K oz Ag | Zn t | | Desert Scheelite | Probable | 9,738 | 0.182 | 10.68 | 0.30 | 17,768 | 3,343 | 28,813 | | Garnet | Probable | 2,085 | 0.120 | 2.78 | 0.22 | 2,507 | 186 | 4,583 | | Total | Probable | 11,822 | 0.171 | 9.28 | 0.28 | 20,275 | 3,529 | 33,396 |

Mineral Reserve Statement Notes:

1. The effective date of Desert Scheelite and Garnet Mineral Reserve Statement is 15 June 2026.

2. The point of reference for Mineral Reserves is at the crusher.

3. Resource blocks were diluted to the selective mining unit (SMU) and additional dilution was added for reporting of Reserves. The QP, RESPEC, who is responsible for the statement of reserves believes that the blocks can be reasonably mined at the SMU size. Desert Scheelite SMU blocks were 5m by 2.5m by 5m in the X, Y, and Z directions respectively. Garnet SMU blocks were 5m by 5m by 2.5m in the X, Y, and Z directions respectively.

4. Reserves are reported based on a 0.040% WO3cutoff grade. The cutoff grade was applied only to the WO3grades. Silver and tungsten are reported as the contained metal within the Probable material processed.