Jindalee Lithium Limited has successfully produced high-grade magnesium oxide exceeding 93% purity from ore at the McDermitt Lithium Project in Oregon, establishing a technical basis to recover a byproduct previously treated as waste.

Testwork completed by Kemetco Research Inc. used two processing approaches on magnesium sulphate brine samples derived from McDermitt ore: adding carbonates to precipitate magnesium carbonate followed by calcination, and crystallising hydrated magnesium sulphate followed by thermal conversion and reductive calcination. Both methods yielded magnesium oxide grades above 93%, reaching up to 93.4%, with calciner conversion rates reaching 99.95%.

The 100%-owned McDermitt project is positioned as one of the largest lithium deposits in the United States. In the November 2024 Pre-Feasibility Study, magnesium was removed from the process as magnesium sulphate without applying any revenue credit. The latest results demonstrate a potential route to convert that stream into magnesium oxide, which serves as a feedstock for primary magnesium metal production and industrial applications such as refractories.

Upon completion of a proposed business combination with Constellation Acquisition Corp I, the McDermitt project is expected to be held by US Elemental Inc. and list on Nasdaq under the ticker 'ULIT'.

“These results are a significant technical step in assessing the magnesium opportunity at McDermitt. We have demonstrated a potential pathway to convert magnesium from a stream treated as waste in the PFS into a high-purity MgO product. Magnesium is strategically important to U.S. industrial and defense supply chains, yet the country remains exposed to a concentrated and import-dependent supply base. Given McDermitt's substantial magnesium endowment, we believe this opportunity warrants further work. It is too early to draw concrete conclusions on commercial viability or Project economics, but our next phase will focus on completing the work necessary to decide whether a magnesium by-product will be incorporated into the upcoming McDermitt Feasibility Study. Subject to those studies, we are encouraged by the potential to evaluate reagent recycling and the introduction of a material magnesium by-product credit at McDermitt.”

— Ian Rodger, Chief Executive Officer of Jindalee and incoming Chief Executive Officer of US Elemental

Following this technical work, Jindalee plans to update the Mineral Resource estimate for McDermitt to include magnesium. Further updates from the magnesium work programs are expected in the fourth quarter of 2026.

Read the full announcement: US Elemental Announces Highly Encouraging Magnesium Testwork Results from the McDermitt Lithium Project