American Tungsten & Antimony Ltd has commenced wet table trials on scheelite-bearing tungsten mineralisation at the Del Sol hydrometallurgical refinery in Amargosa Valley, Nevada.

The testwork is evaluating material sourced from the company's Dutch Mountain Tungsten Project in Utah, which is intended to supply the Dutch Mountain Tungsten Concentrator under a hub-and-spoke strategy, alongside third-party material sourced proximal to Del Sol.

The trials form the front-end concentration step required to expand the facility into ammonium paratungstate (APT) processing capability. In parallel with the gravity testwork, engineering proposals have been received from shortlisted international firms for the proposed APT expansion. The company reported that requests for proposal had been issued on 6 August 2026, and it now targets the engagement of a preferred engineering firm within the next two weeks.

“AT4 is entering into an exciting phase - with tungsten and antimony samples from both internal and nearby third-party sources being processed at Del Sol to determine optimum conditions for the production of both tungsten APT and antimony flake.” 

“The engaged consultants, metallurgists and engineers at Del Sol are working alongside our team on the preparation for upcoming trials to identify the fastest and most efficient path forward for both circuits to enable Del Sol to be expanded.” 

— Casper Adson, Chief Executive Officer

Alongside the tungsten program, approximately 3 tonnes of stibnite-bearing mineralisation has been hauled from the White Spar Antimony Mine to Del Sol for wet table trial work, accompanied by samples and drill core from the Antimony Canyon Project in Utah. The White Spar asset is being acquired alongside the Del Sol Refinery under a binding share sale and purchase agreement announced on 28 July 2026.

Metallurgical results from the ongoing wet table trials will be used to optimise concentrate production and inform the restart trial of the Del Sol antimony flake circuit. American Tungsten & Antimony targets the commencement of the restart trial by the end of the September quarter 2026, with Chief Executive Officer Casper Adson and the Nexus Metals team also scheduled to visit Washington D.C. and New York next week to advance the company's U.S. domestic refining strategy.

Read the full announcement: Del Sol Hydromet Refinery Operational Update