American Tungsten Engages Metso for US APT Refinery Study as CEO Meets White House
Key Takeaways
- AT4 has engaged Metso Finland Oy — a EUR 5.3 billion revenue, ~18,000-employee global process technology supplier — following a competitive five-proposal RFP process to complete an FEL1 Concept Study for APT production at the Del Sol Refinery in Nevada.
- The study is sized to a proposed Phase 1 design capacity of 2,500 tonnes per annum of APT, with a pathway to a potential Phase 2 of 5,000 tpa — design capacities intended to support future US Federal critical minerals funding applications.
- Executive Order 14415, signed 20 July 2026, requires US defence contractors to source covered materials domestically or from allied nations, with waiver restrictions taking effect from 1 January 2027 — creating a direct, time-sensitive policy tailwind for domestic APT capacity.
- CEO Casper Adson is conducting meetings in Washington D.C., including at the White House, with the program extended to accommodate additional agency meetings, with a key focus on expanding progress under the DOE Mines & Metals Capacity Expansion program.
- The Del Sol Refinery acquisition remains conditional and has not yet completed — shareholders should not assume it will, and no development can proceed until it does.
AT4 engages Metso for APT refinery expansion study as CEO meets at the White House
American Tungsten & Antimony Ltd (ASX: AT4; OTCQB: ATALF) has engaged Metso Finland Oy to complete an FEL1 Concept Study for an ammonium paratungstate (APT) production circuit at the Del Sol Refinery in Amargosa Valley, Nevada. The Del Sol Refinery remains subject to a conditional acquisition announced on 28 July 2026, which has not yet completed, and shareholders should not assume that it will. Concurrently, CEO Casper Adson has commenced a program of meetings in Washington D.C., including at the White House, with US government agencies and key stakeholders.
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Key highlights at a glance
- Metso Finland Oy engaged following a competitive RFP process that attracted five proposals
- Study sized to a proposed Phase 1 design capacity of 2,500 tonnes per annum (tpa) of APT, with a pathway proposed to a potential Phase 2 of 5,000 tpa (these are design capacities, not production targets)
- Study deliverables include a preferred conceptual flowsheet, preliminary mass balance, main equipment list, AACE Class 5 capital cost estimate, indicative operating cost estimate, permitting commentary, and a roadmap to FEL2 (Prefeasibility Study)
- Study intended to support future applications under US Federal critical minerals funding programs
- CEO White House engagement underway, with the program extended to accommodate additional agency meetings
Why APT production on US soil matters
APT, ammonium paratungstate, is an intermediate product in the tungsten supply chain. Before tungsten can be processed into the components used in defence systems, aerospace applications, and industrial manufacturing, raw tungsten concentrate must first be converted into APT. Think of it as a necessary halfway step that domestic US capacity is limited in performing.
That gap is the problem. Domestic US capacity to convert tungsten concentrate into APT is limited, meaning the country’s defence and advanced manufacturing sectors currently depend on offshore sources, many of which are controlled by geopolitical adversaries.
A brownfield expansion addresses this differently from building a new plant from scratch. Using an existing, already-permitted facility like Del Sol means the infrastructure, footprint, and regulatory groundwork are already in place, which has the potential to materially reduce both capital requirements and the time needed to establish domestic APT capability.
The policy backdrop has sharpened the urgency considerably. Executive Order 14415, signed on 20 July 2026, requires US defence contractors and their subcontractors to source covered materials domestically or from allied nations. Waiver restrictions take effect from 1 January 2027, and a contractor’s failure to qualify a domestic source will not constitute non-availability unless active and adequately funded qualification efforts are already underway. That creates a direct and time-sensitive incentive for the US government to support domestic tungsten processing capacity.
Del Sol study scope and the Metso selection
What the FEL1 study will deliver
The scope of work assigned to Metso covers seven key deliverables:
- Confirmation of the feed basis (concentrate grade, tonnage, contaminant profile) and review of Del Sol site constraints and opportunities, including existing equipment and utilities capacity
- Identification and screening of candidate hydrometallurgical process routes for APT production, and selection of a preferred route with documented justification
- Development of a Block Flow Diagram, Process Description, and preliminary Process Design Criteria for the preferred route
- Preliminary mass balance and main equipment list for Phase 1, with an indicative Phase 2 expansion case, utility and reagent consumption estimates, and waste characterisation
- AACE Class 5 capital cost estimate for Phase 1 with an indicative Phase 2 estimate, and an indicative operating cost estimate covering labour, reagents, power, and maintenance
- A technical risk assessment identifying key process and project risks with proposed mitigations, together with a data gap register
- A recommended roadmap to FEL2 (Prefeasibility Study), including recommended further test work and an indicative schedule
One important caveat on those cost estimates: AACE Class 5 accuracy carries a range of -50% to +100%. This is an order-of-magnitude estimate suited to internal screening and decision-making, not a basis for a development decision. Advancing beyond the Study would require further test work, an FEL2 study, completion of the Del Sol acquisition, permitting, and funding the company has not yet secured.
Why Metso was selected
Metso was chosen from five competitive proposals received through the RFP process. The selection criteria centred on its demonstrated hydrometallurgical process development and plant engineering capability across the unit operations relevant to APT production, the depth 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.
Metso is a globally recognised process technology and equipment supplier. The company had close to 18,000 employees across approximately 50 countries at the end of 2025, with EUR 5.3 billion in 2025 sales. It is listed on the Nasdaq Helsinki.
Washington D.C. engagement and the investment case
White House meetings and government engagement
CEO Casper Adson and the Nexus Metals team have commenced meetings in Washington D.C., including at the White House, with US government agencies and key stakeholders. Mr Adson extended his time in Washington to accommodate additional agency meetings.
A key focus of the engagement is continuing and expanding progress with the US Department of Energy in relation to the ASCEND-Sb Project, for which AT4 was selected to enter award negotiations under the DOE Mines & Metals Capacity Expansion program (refer ASX announcement dated 19 August 2026). The company is concurrently progressing existing agency applications and initiating new ones, including in connection with the tungsten APT capability described in this announcement.
Director quotes
CEO Casper Adson
“Tungsten is one of the most strategic commodities for the United States. Defence, aerospace and industrial manufacturing are all exposed as its supply is offshore and controlled by adversaries. Rebuilding the ability to convert tungsten concentrate into tungsten APT on US soil is a question of national interest. Del Sol is a constructed and permitted hydrometallurgical plant on American soil. Putting an APT circuit inside an existing footprint rather than building on a greenfield site has the potential to materially reduce the capital required and the timeline to commence producing a domestic tungsten product. The proposed Phase 1 circuit is to be sized at 2,500 tpa APT, with a potential future Phase 2 expansion to be proposed for 5,000 tpa APT. The capital and operating cost estimates from the study will enable the Company to engage US funding programs available for the support of domestic critical minerals sovereignty and independence.”
Executive Chairman Timothy Morrison
“The re-establishment of a domestic tungsten supply chain is a clearly stated priority of the United States government, and engagement with the relevant agencies and funding programs requires substantiated technical and cost data. Metso, a recognised international supplier of process technology, equipment and services to the minerals processing and metals refining industries, will apply its extensive expertise to the assessment of a tungsten APT circuit at Del Sol. The resulting flowsheet, capital and operating cost estimates will be prepared to a standard suitable for review by government, offtake counterparties and prospective funding partners. The Board regards this as a significant step forward. It advances Del Sol towards its goal as a multi-commodity sovereign metals refinery to accelerate America’s critical minerals independence. It will enable the Company to engage constructively with the United States government on domestic tungsten APT supply alongside its current antimony capacity.”
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Next steps and the pathway forward
- Completion of the FEL1 Concept Study (no timeline has been disclosed by the company)
- Study outcomes intended to inform future applications under US Federal critical minerals funding programs
- Roadmap to FEL2 (Prefeasibility Study) to be defined within the Study deliverables
- The conditional acquisition of the Del Sol Refinery must complete before any development can proceed; shareholders should not assume completion
- Continued Washington D.C. government and agency engagement, building on White House meetings already underway
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