ASX: AT4 | OTCQB: ATALF | 2 September 2026

American Tungsten & Antimony Limited has engaged Metso Finland Oy to complete an FEL1 Concept Study for an ammonium paratungstate production circuit at the Del Sol Refinery in Amargosa Valley, Nevada. The Study will assess siting an APT circuit within the existing permitted Del Sol facility, using its hydrometallurgical infrastructure and utilities, as an alternative to a standalone greenfield tungsten processing plant.

This engagement completes a sequence AT4 set out publicly and then executed against on schedule.

For a company at AT4’s stage, meeting a stated timetable is not a trivial signal. The engineering appointment was the gating item for everything downstream, because capital and operating cost estimates are what federal funding programs require before they will engage substantively.

Metso is headquartered in Espoo, Finland and listed on the Nasdaq Helsinki. At the end of 2025 it had close to 18,000 employees across around 50 countries, with 2025 sales of approximately EUR 5.3 billion. The capability relevant to this Study spans hydrometallurgical process development, flowsheet modelling, autoclave leaching, impurity and molybdenum removal, solvent extraction and crystallisation, supported by dedicated research and test work facilities in Pori, Finland.

The engagement followed a competitive request for proposal process issued to international engineering firms, from which five proposals were received. AT4 selected Metso on the basis of its demonstrated hydrometallurgical process development and plant engineering capability across the unit operations relevant to APT production, the depth and availability of its nominated technical team including personnel with direct tungsten chemical plant process development and commissioning experience, and its in-house flowsheet modelling and cost estimating capability.

The scope matters here. Molybdenum removal, impurity removal, solvent extraction and APT crystallisation are the specific unit operations that make tungsten conversion difficult. Appointing a firm with in-house capability across all of them, rather than a generalist, is a substantive choice rather than a procedural one.

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The Company has stated that the Study will provide the technical basis required to support future applications under United States federal critical minerals funding programs. That is the practical purpose of the exercise. Agencies do not fund concepts; they fund engineered packages with a documented basis of estimate.

Del Sol is an existing alkaline leach and electrowinning hydrometallurgical facility. The Study will assess whether an APT circuit can be sited within that existing permitted footprint rather than on a greenfield site.

Chief Executive Officer Casper Adson framed the rationale in the announcement, stating that putting an APT circuit inside an existing footprint rather than building greenfield has the potential to materially reduce the capital required and the timeline to commence producing a domestic tungsten product, and that the resulting capital and operating cost estimates will enable the Company to engage US funding programs supporting domestic critical minerals sovereignty.

Executive Chairman Timothy Morrison stated that engagement with the relevant agencies and funding programs requires substantiated technical and cost data, and that the resulting flowsheet and estimates will be prepared to a standard suitable for review by government, offtake counterparties and prospective funding partners. He described the engagement as advancing Del Sol towards its goal as a multi-commodity sovereign metals refinery, enabling the Company to engage the United States government on domestic tungsten APT supply alongside its current antimony capacity.

On 20 July 2026 President Trump signed Executive Order 14415, titled Securing America’s Defense Supply Chains and Ensuring Domestic Acquisition of Critical Materials. The order directs the Department of War to substantially curtail the waivers that have historically allowed defence contractors to source covered materials under 10 U.S.C. 4872 from China and other non-compliant suppliers.

From 1 January 2027 the Secretary of War and the service secretaries are to cease issuing waivers under section 4872(c)(1) for the acquisition of covered materials, except where a contractor submits a formal mitigation plan accepted by the Secretary. Critically for domestic producers, the order provides that a contractor’s failure to qualify a domestic source does not itself constitute non-availability justifying a waiver, except where the contractor demonstrates active and adequately funded qualification efforts. The order also directs supply chain mapping back to the origin of raw materials across prime contractors and subcontractors at every tier.

Tungsten metal powder and tungsten heavy alloy are covered materials under section 4872. The practical effect is that defence primes and their subcontractors face a hard deadline to establish compliant tungsten sourcing, and that qualifying a domestic source becomes a compliance obligation rather than a commercial preference.

Two qualifications are worth stating plainly. Most of the order’s broader contractor requirements are not immediately effective and must first be implemented through Department of War policy, regulation or contract clauses. The order does not appropriate new funding, make awards, establish procurement quantities or create an across-the-board domestic content mandate, and its implementation is expressly subject to applicable law and the availability of appropriations. It creates demand pressure and a timetable, not a purchase order.

Chief Executive Officer Casper Adson, with members of the Nexus Metals team, has commenced a program of meetings in Washington D.C., including at the White House, with United States government agencies and key stakeholders. The Company states the meetings are focused on the agencies with which it is seeking to partner on grant and funding instruments in both the near and longer term, and that a key focus is continuing the progress made with the Department of Energy on the ASCEND-Sb Project. AT4 is concurrently progressing existing applications with other agencies and initiating new applications where opportunities are identified, including in connection with the tungsten APT capability. Mr Adson has extended his time in Washington to accommodate additional meetings.

AT4 has also released a video in which David Bernhardt, Chairman of the Company’s Strategic Advisory Board and former US Secretary of the Interior, together with Adson and Craig Wiita, President of Nexus Metals and Chief of Operations at the Del Sol Refinery, take viewers inside the facility and set out its role in the Company’s strategy.

Beyond the DOE selection announced on 19 August 2026, the Company has stated it has no agreement, commitment, contract, grant, offtake or funding arrangement with any United States government agency or department, and there is no certainty that these meetings will result in any agreement, funding, offtake or transaction.

Across three announcements in thirteen days AT4 has moved from federal shortlisting to physical trials to an engaged international engineering firm. The strategy is internally consistent: use an existing permitted brownfield facility to shorten the capital and time required to establish domestic tungsten conversion, generate the engineered cost data that federal programs require, and present that package to agencies against a regulatory deadline that takes effect on 1 January 2027.

The constraints are equally clear. The Study has not started. Its output will be an order of magnitude estimate at minus 50 to plus 100 per cent accuracy, which is explicitly not sufficient to support a development decision. Advancing further would require additional test work, an FEL2 Prefeasibility Study, completion of the Del Sol acquisition, permitting and funding that the Company has not secured. The design capacities are engineering assumptions, not production targets, and no JORC Mineral Resource or Ore Reserve exists for any AT4 project.

What has changed is that AT4 now has a credible international engineer working on the technical basis of the case. What has not changed is that everything downstream of that remains conditional.

This article is general information only. It is not financial product advice and does not take into account any person’s objectives, financial situation or needs. Investors should read the Company’s ASX announcements in full, including those dated 28 July, 19 August, 21 August and 1 September 2026, together with the cautionary and forward-looking statements contained in them, and obtain independent advice before making any investment decision.