ChemX Materials has taken a crucial step towards high-purity alumina production after cranking up the early-stage commissioning of a leach circuit at its innovative “HiPurA” pilot plant in Western Australia. The leach circuit is a critical initial part of ChemX's purification process in its aim to produce 99.99 per cent, or “four nines”, purity HPA from its planned 24-tonne per annum plant.