American Tungsten & Antimony (ASX:AT4) is acquiring a constructed antimony refinery in Nevada and an associated mine in Arizona as part of its strategy to build a domestic US supply chain for critical minerals.
The company has executed a share sale and purchase agreement with Nexus Metals to acquire 100% of the Del Sol refinery in Nevada and the White Spar Antimony Mine in Arizona for total consideration of US$3 million ($4.29 million) in cash plus approximately 1.06 billion AT4 shares, options, and performance rights.
The Del Sol refinery is a constructed and permitted antimony flake refinery that has produced electrolytic antimony flake within the last six months using an alkaline leach and electrowinning process.
The facility holds permits to process up to 18,500 tonnes of feed per year, with plans to expand permitted capacity to 100,000 tonnes annually.
CEO Casper Adson will meet with the Nevada Division of Environmental Protection on 29 July to progress approvals for the proposed capacity increase and permit expansion for tungsten refining.
“The Del Sol Refinery is a constructed and permitted antimony refinery in a market with minimal domestic capability, combined with feedstock from White Spar and Antimony Canyon,” Adson says.
“It provides AT4 with the ability to produce antimony metal flake and a roadmap into military specification antimony products entirely on US soil.
“This proposed acquisition is a major step forward for AT4 establishing a vertically integrated domestic US supply chain of strategically important tungsten and antimony products for US defence [and] semiconductor and critical minerals markets.”
The refinery provides scope for expansion into production of ammonium paratungstate and higher value antimony products, including Regulus II antimony metal, antimony trisulphide, and sodium antimonate.
AT4 has already received study proposals from international engineering firms for a US tungsten refinery cost estimate.
Meanwhile, the White Spar Antimony Mine is a historic antimony mine in Yavapai County, Arizona, currently supplying the Del Sol Refinery, with documented historic underground workings and stibnite mineralisation.
The acquisition supports US defence industrial policy priorities, as antimony and tungsten are foundational materials across the defence industrial base. China has progressively imposed export controls on both metals since 2024, while US law prohibits Department of War procurement of tungsten and certain critical minerals from China, Russia, Iran, or North Korea from 1 January 2027.
Completion of the proposed transaction is conditional on shareholder approval, regulatory approvals, and Nexus Metals exercising its option to acquire Del Sol Refining. The transaction includes deferred milestone payments of up to US$40 million based on processing throughput achievements and completion of a Definitive Feasibility Study.
The company intends to commence planning immediately to scale up antimony flake production and expand the Del Sol facility into ammonium paratungstate production. Laboratory-scale testwork on scheelite concentrate for tungsten processing development will also begin following completion.
AT4 reports a pro forma cash balance of $26.5 million and is targeting a Nasdaq listing in the fourth quarter of 2026.
American Tungsten & Antimony is focused on the exploration and development of antimony and tungsten projects in the US.
Write to Paula Fabe at Mining.com.au
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