Vancouver-based Stillwater Critical Minerals has reported a 62% increase in the updated mineral resource estimate for its Stillwater West platinum group element, nickel, copper, cobalt and gold project,  in Montana, in the US.

The study showed significant increases in tonnage and contained metal at both a bulk tonnage 0.20% nickel-equivalent cut-off and 0.35% nickel-equivalent higher grade bulk tonnage cut-off.

A high-grade, selective mining component at a 0.70% nickel-equivalent cut-off is presented for the first time.

The Stillwater West project now boasts a base case inferred mineral resource of 1.6-billion pounds of nickel, copper and cobalt and 3.8-million ounces  of palladium, platinum, rhodium and gold (4E) in a constrained model totalling 255-million tonnes at an average grade of 0.39% total estimated recovered nickel-equivalent (or 1.19 g/t palladium equivalent).

At a base case 0.20% nickel-equivalent cut-off, Stillwater reported significant increases in contained metals over the 2021 study. Nickel increased by 52% to 1.05-billion pounds, copper by 44% to 499-million pounds, cobalt by 31% to 91-million pounds, palladium by 56% to 2.05-million ounces, platinum by 66% to 1.26-million ounces, gold by 30% to 395 000 oz and rhodium by 76% to 115 000 oz.

The selective mining high-grade component yielded 11.6-million tonnes at 1.05% total nickel-equivalent, as 0.56% nickel, 0.33% copper, 0.03% cobalt with 0.54 g/t palladium, 0.27 g/t platinum, 0.15 g/t gold and 0.019 g/t rhodium. Expansion of this high-grade component results from the addition of high-grade mineralization encountered in the 2021 drill campaign.

Stillwater reports that 2.27-billion pounds of chromium have been inventoried. Chromium is defined by the US government as a critical mineral.

“We are very pleased with the expanded 2023 resource, which returned substantial increases in tonnage and contained metals while also increasing the high-grade component. Overall, these increases speak to the fantastic growth potential and under-explored nature of the Stillwater West project, and to our ability to rapidly increase resources in these wide-open deposits with targeted expansion drilling at low discovery cost,” said president and CEO Michael Rowley.

“Our Stillwater West project, with its world-class endowment of eight critical minerals, is unique in the United States as a district-scale asset located in an active, producing district that has a long history of large-scale critical mineral production. The US government has recognized the importance of critical minerals to both economic and national security interests and is taking increasing action to secure domestic supply of these key metals at a time when we are advancing Stillwater West and demonstrating its potential. Our exceptional team, with multi-decades of experience at both Stillwater and in the parallel layered geology of the Bushveld Igneous Complex, is well-positioned to advance the asset. We look forward to continuing to build on our success and low discovery costs as we finalize our follow-up expansion programmes for 2023.”