American Tungsten & Antimony (ASX:AT4) reports ‘high-grade’ silver results from White Spar Antimony Mine in Arizona, US, and continued antimony success at Antimony Canyon as the company strengthens its US mine-to-metal processing pathway.
The company recently produced 99.8% purity antimony ingot from White Spar material at its Del Sol Refinery. The results exceed Regulus II specifications and demonstrate the viability of its domestic processing strategy.
New silver assays from White Spar include 665 grams per tonne silver (Ag) from sample WS008, 394g/t Ag from WS007, and 432g/t Ag from WS009. The results have prompted AT4 to assess potential silver recovery as an additional product stream at Del Sol.
CEO Casper Adson says the silver results open potential for an additional saleable product at Del Sol.
“The silver results are particularly encouraging. […] We are now investigating whether silver recovery could add value to our processing operations and strengthen the refinery’s economics,” Adson states.
“Our mine-to-metal strategy is not dependent on developing any single mine. By sourcing feedstock from existing workings, third-party suppliers and potentially our own exploration projects, we aim to build a flexible, commercially competitive US critical minerals business.”
The company collected 11 rock chip samples across two parallel mineralised zones at White Spar, with eight samples along a 600m central corridor and three on a separate eastern lode 280m away.
The ‘highest silver grades’ correlate with elevated barium and lead, consistent with historically documented silver-bearing barite vein systems.
Del Sol acquisition and supply strategy
At the Antimony Canyon Project in Utah, drilling at the Little Emma prospect returned 1.49m @ 18.23% antimony (Sb) from 28.35m in hole ACP26DD023. This includes 0.36m @ 68.1% Sb from 29.05m — the highest single sample grade of the program.
The result confirms a second discrete ‘high-grade’ antimony pod within the stratabound system. Mineralisation in this system occurs through carbonate dissolution and replacement within the calcareous Salt and Pepper unit of the Paleocene Flagstaff Formation.
AT4 operates a diversified feedstock strategy for Del Sol, sourcing material from existing workings, third-party arrangements, and future production from exploration projects. The company will assess relative development timelines and commercial returns to prioritise feedstock sources.
White Spar forms part of AT4’s proposed Del Sol acquisition announced in July, which remains subject to completion conditions including shareholder approval.
American Tungsten & Antimony is an Australian developer advancing an integrated US mine-to-metal antimony and tungsten portfolio.
Write to JC Villarba at Mining.com.au
Images: American Tungsten & Antimony
