On 28 July 2026, AT4 announced the execution of a Share Sale and Purchase Agreement with Nexus Metals LLC to acquire 100% of Del Sol Refining Inc, the owner of the Del Sol Refinery in Amargosa Valley, Nevada, and the White Spar Antimony Mine in Yavapai County, Arizona.

Earthworks and high-grade stibnite at the White Spar Antimony Project, Yavapai County, Arizona

Strip away the metallurgy and this acquisition is a bet on one thesis: the US Government is now the most important customer, lender and grant-maker in critical minerals, and it writes its biggest cheques to companies that own both the mine and the refinery.

Eight days before AT4's announcement, President Trump signed Executive Order 14415, "Securing America's Defense Supply Chains and Ensuring Domestic Acquisition of Critical Materials" (20 July 2026). The order tightens the existing prohibition on Department of War procurement of critical minerals mined, refined or produced in China, Russia, Iran or North Korea. From 1 January 2027, standard waivers dry up. Contractors must demonstrate "exhaustive efforts" to qualify a compliant domestic source before claiming non-availability, and must map their supply chains back to the raw material.

Read that carefully. The Executive Order does not just create demand for domestic antimony and tungsten. It creates demand for qualified domestic antimony and tungsten. Qualification takes a facility, a permit and product in hand. A company that starts permitting today is years away. A company that acquires a constructed, permitted refinery can start qualification work now. That is the entire logic of Del Sol.

Layered on top is Project Vault, the approximately US$12 billion US Strategic Critical Minerals Reserve launched in February 2026, funded by a US$10 billion EXIM loan and roughly US$2 billion in private capital. Its appointed procurement agents (Hartree Partners, Traxys and Mercuria) have begun signing offtake arrangements with critical minerals producers, with antimony among the minerals targeted by the reserve. AT4 is transparent that it has no current arrangement with Project Vault, but the reserve establishes a standing, policy-backed buyer for exactly what Del Sol is designed to produce.

The federal funding record over the past twelve months shows a clear pattern. The largest commitments have gone to companies pairing upstream supply with downstream processing. Tap each precedent to expand it:

The instruments span the full federal toolkit: DPA Title III grants, DLA National Defense Stockpile procurement, EXIM project debt and FAST-41 permitting acceleration. None of this guarantees AT4 a dollar. But it defines the eligibility criteria, and before Del Sol, AT4 did not fully meet them. After Del Sol, it arguably meets them twice over.

What separates AT4 from every peer on that funding list is that each of them is essentially a single-metal story. AT4's platform now spans both of the defence industrial base's foundational metals.

If the tungsten permit extension is granted, AT4 believes Del Sol would become the only refinery in the US producing both tungsten and antimony products. Executive Chair Tim Morrison put the contrast plainly: AT4's closest US-listed peer "relies substantially on ore sourced from outside the United States", whereas Del Sol gives AT4 a pathway to refining capability fed from wholly domestic sources, a true mine-to-metal American supply chain. That is precisely the supply-chain shape EO 14415 tells defence primes to go and find.

A technical detail with outsized permitting value: Del Sol's alkaline leach circuit (pictured) processes stibnite without generating SO₂, the pollutant stream that forces conventional smelters into dedicated capture and abatement. That is expected to keep the site below Title V major-source air permitting thresholds, subject to confirmation, which means one less multi-year federal process between here and production.

The alkaline leach circuit at Del Sol

AT4 has not received a Pentagon contract, and this deal does not promise one. What it does is change the category AT4 competes in. Twelve months ago this was an explorer with promising ground. Today, subject to completion, it holds assets spanning every stage of the value chain within the United States, from mine through concentrate to refined product, across both tungsten and antimony: a portfolio AT4 believes no other US antimony and tungsten company currently possesses.

With EO 14415's waiver cliff arriving on 1 January 2027, Project Vault's procurement agents in the market, and a federal funding record that consistently rewards integrated mine-to-metal platforms, AT4 has positioned itself squarely in front of the widest, best-funded demand signal in US critical minerals. At a market capitalisation a fraction of its US-listed peers, that repositioning is the story.

This article is general commentary for information purposes only and is not financial product advice, nor a recommendation to buy or sell any security. It does not take into account your objectives, financial situation or needs. The Del Sol acquisition remains subject to shareholder approval, regulatory approvals and other conditions precedent, and may not complete. The Del Sol facility is not currently in continuous commercial production; planned products, capacity expansions, permits and the proposed Nasdaq listing are targets only and are not assured. White Spar has no mineral resource estimated under JORC, NI 43-101 or any recognised code.