Impact Minerals (ASX:IPT) has recorded uranium and thorium levels as low as below 1 part per billion in high-purity alumina (HPA) samples from its Lake Hope Project in Western Australia.
Analysis by Eurofins EAG Laboratories shows three of four HPA samples achieved uranium and thorium levels at or below 1ppb using Impact’s low-temperature leach process, without any dedicated removal steps.
Impact says the ‘ultra-low’ levels meet industry standards for ‘zero-alpha’ and ‘low-alpha’ alumina required in advanced semiconductor packaging and thermal management.
Managing Director Michael Jones says the ‘exceptionally low’ uranium and thorium content achieved directly from the Lake Hope flowsheet is a ‘standout feature’ of the results, especially as the process did not involve a dedicated radionuclide removal stage.
“We believe this is an excellent starting point for engaging with the semiconductor industry, where ultra-low-alpha radiation alumina is required for advanced semiconductor packaging, and with thermal management materials, where even trace radioactive impurities can compromise chip reliability,” Jones notes.
“It is evident that Lake Hope HPA has the potential to consistently deliver this standard with ongoing refinement of our metallurgical process.
“The low levels of these elements are driven by yet another advantage of the Lake Hope sediments: not only do they process in a relatively straightforward manner, but they also contain relatively small amounts of these elements to begin with.”
For the three samples, Eurofins recorded 4N HPA purity at over 99.99% aluminium oxide (Al2O3), with total measured impurities ranging 47.5–68.6 parts per million. The fourth sample achieved 99.977% Al2O3 purity.
Impact says the results provide a technical foundation for pilot-scale optimisation work, which is currently underway at Edith Cowan University through its Cooperative Research Centre Projects program.
The company intends to undertake further confirmatory analysis, mass-balance testwork, and assessment of existing purification stages on additional HPA batches, among other future workstreams.
Impact holds an 80% interest in the Lake Hope Project through its subsidiary Playa One, where it completed a Prefeasibility Study in June 2025.
Impact Minerals is focused on discovering and developing strategic, battery, and precious metals projects across Australia.
Write to Paula Fabe at Mining.com.au
Images: Impact Minerals
