Jindalee Lithium (ASX:JLL) has produced ‘high-grade’ magnesium oxide from ore at its McDermitt Lithium Project in the US.
Testwork converted magnesium sulphate from McDermitt ore into magnesia (MgO) with 93.40% equivalent MgO content, establishing proof of concept for a potential higher-value magnesium by-product at one of the largest lithium deposits in the US.
Undertaken by Kemetco Research, the testwork investigated producing magnesia from magnesium sulphate brine samples using two approaches. The first involved adding carbonates to precipitate magnesium carbonate followed by calcination to produce magnesium oxide.
Meanwhile, the second approach crystallised hydrated magnesium sulphate from brine, followed by thermal conversion and reductive calcination.
Both approaches produced magnesia grades greater than 93% MgO, with conversion in the calciner reaching 99.95% MgO for both methods.
The results provide a technical basis for Jindalee to assess whether magnesium streams previously treated as waste in its Prefeasibility Study (PFS) can be converted into higher-value products.
The company completed the McDermitt PFS in November 2024, which identified scope for process optimisation and potential magnesium by-product recovery.
Managing Director Ian Rodger says 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 magnesium oxide product,” Rodger says.
Magnesium metal is designated a high-risk critical mineral by the US Government and is important to industrial, defence, and advanced-manufacturing supply chains. Key applications include aluminium alloys, automotive lightweighting, aerospace components, titanium production, and steel desulphurisation.
Jindalee has commissioned preliminary independent market analysis to inform its magnesium product strategy, which supports magnesia as a logical product for evaluation.
The company intends to conduct additional market and engineering studies to determine the financial viability of producing magnesium by-products.
It will also conduct additional testwork and update its mineral resource estimate to include magnesium.
Further updates are expected in Q4 2026.
Jindalee Lithium owns 100% of the McDermitt Lithium Project with unencumbered offtake rights, positioning the asset as one of the largest lithium resources in the US.
Write to Paula Fabe at Mining.com.au
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