Impact Minerals HPA hits 4N purity, near-zero uranium for chips

Impact Minerals (ASX: IPT) has reported independent high-sensitivity assays for four high-purity alumina (HPA) samples produced from the Lake Hope feedstock. The material was processed through the patented low temperature leach (LTL) process that underpinned the project's 2025 pre-feasibility study.

Analysis by Eurofins EAG Laboratories returned one sample with uranium and thorium below the analytical detection limit of 1 part per billion. Two samples showed thorium at or below 1ppb and uranium at 4ppb and 10ppb. The fourth sample had thorium at 10ppb and uranium at 9ppb.

Three samples achieved 4N HPA purity, meaning more than 99.99 percent aluminum oxide with total measured impurities below 100 parts per million. The best sample reached 4N5 across a wide range of impurities. The fourth sample hit 99.977 percent after refinements to the initial caustic leach reaction, with lower phosphorus, magnesium and potassium concentrations.

Lake Hope's results meet industry thresholds for low-alpha and zero-alpha alumina used in advanced semiconductor packaging and thermal management. Radioactive impurities in materials placed near chips and memory devices must be removed to prevent decay that can cause data errors or device failures. Most producers need a dedicated radionuclide-removal step to hit those levels.