American Tungsten & Antimony Ltd has commenced a restart campaign at the Del Sol Hydromet Refinery in Amargosa Valley, Nevada, moving ahead of its previous schedule to produce antimony flake from mineralisation sourced at the White Spar Antimony Mine in Yavapai County, Arizona.

The restart campaign marks the first physical demonstration of the United States vertical integration strategy underpinning American Tungsten & Antimony. The processing work is being undertaken in cooperation with Nexus Metals while the companies await completion of the acquisition agreed in July 2026. That agreement remains subject to conditions precedent, including shareholder approval at a general meeting scheduled for 21 September 2026, and must be satisfied or waived by 27 September 2026. American Tungsten & Antimony currently holds no legal or beneficial interest in the refinery or the White Spar asset.

Operating activities at the Nevada facility have been fast-tracked to generate sample material for qualification discussions with prospective offtakers, strategic partners, and United States government agencies and defense primes. The leach and electrowinning circuit is processing White Spar material to produce antimony flake, which will subsequently be used to manufacture higher-value specialty items such as Regulus II antimony ingots and antimony trisulphide. Operating data gathered during the campaign will also feed into expansion studies for the Del Sol facility.

“Commencing the restart campaign at the Del Sol refinery is a critical milestone for the Company. AT4 has fast-tracked the restart to demonstrate the capability of the Del Sol circuit using US-sourced material. An existing, permitted facility enables the circuit to be restarted without the need to add new infrastructure or lengthy permitting delays.”

— Casper Adson, Chief Executive Officer

The ongoing campaign is operating within the facility's existing permitted feed envelope, allowing the work to proceed rapidly while keeping capital expenditure low. In parallel, tungsten test work continues at Del Sol on material from Dutch Mountain, Tennessee Mountain and third-party sources as part of the company's broader ammonium paratungstate expansion planning.

Read the full announcement: Del Sol Refinery Restart Campaign Commencing