American Tungsten & Antimony plans Del Sol refinery restart

American Tungsten & Antimony (AT4) has launched planning to restart and expand the Del Sol refinery in Nevada, while also advancing exploration at its White Spar antimony mine in Arizona. The moves hinge on the company’s proposed $28 million acquisition of both assets, announced in July 2026. If completed and funded, AT4 intends to restart the refinery’s antimony flake circuit by September 2026, using ore from White Spar. The project is designed to secure domestic supply of antimony, a critical mineral used in flame retardants, batteries, and military applications.

The refinery restart will roll out in phases, starting with small test batches to validate performance before scaling up. AT4’s team has already assessed plant condition, staffing, lab capacity, and the step-by-step restart sequence. Alongside, the company will collect operating data on recovery rates, chemical use, energy consumption, and maintenance needs. This data could support future expansion plans, help qualify customers, and strengthen applications for U.S. government grants, including Defense Logistics Agency and Defense Production Act funding. AT4 cautioned it has not yet received any federal support and offers no guarantee of future approvals.

To broaden output, AT4 has asked global engineering firms to bid on projects that could add antimony flake capacity and new product lines, including Regulus II antimony metal, antimony trisulphide, sodium antimonate, and ammonium paratungstate. Del Sol is currently permitted to process up to 18,500 short tons of feed per year on 40 acres of private land, with 10 acres eyed for future development. The company has held early talks with Nevada regulators about potentially raising the cap to about 100,000 short tons annually and adding ammonium paratungstate production—though these are regulatory limits, not production targets.

Meanwhile, at White Spar, AT4 plans metallurgical tests, geological mapping, expanded sampling, and—if approved—a first drilling program. The goal is to pull a bulk sample for processing through Del Sol to test the full mine-to-refinery route. No official mineral resource estimates have been made for White Spar yet. AT4 is also advancing two other U.S. projects: Antimony Canyon in Utah and the Tennessee Mountain tungsten project in Nevada. The company is building a strategy to produce antimony and tungsten closer to American manufacturers and defense contractors, aiming to reduce reliance on foreign supply.