ASX-listed Australian Rare Earths has started with pilot processing of about 30 t of material from the Koppamurra rare earths project, in South Australia, after officially opening its pilot-scale processing plant at the Australian Nuclear Science and Technology Organisation's (Ansto's) facilities in Sydney.

Australian Rare Earths is the first industry partner of Ansto to use the purpose-build, clay-hosted rare earth pilot processing plant, which the company says reflects the confidence it has in Koppamurra's readiness for the next stage of its development.

The pilot facility provides Australian Rare Earths with a low-cost pathway to generate technical data required to advance the project toward a bankable feasibility study. The pilot facility will validate the full flowsheet for the ionic clay-hosted mineralisation at Koppamurra.

"With Koppamurra ore now being processed through a continuously operating pilot circuit, we are now generating engineering data and product samples for direct evaluation by potential customers and offtake partners. With our first mixed rare earth oxide sample expected in late September, this programme is delivering what we need to finalise Koppamurra's process design and drive toward an investment-ready outcome," says Australian Rare Earths MD and CEO Travis Beinke. He adds that heap leaching activities are expected to be completed by December.

For context, during commissioning of the pilot-scale facility, Australian Rare Earths confirmed the design basis for key operating parameters such as agglomerate preparation, irrigation flow rates and lixiviant makeup requirements. The commissioning process also validated the company's column loading and irrigation approach, demonstrating that the pilot plant design and operating configuration are performing as intended.

The commissioning phase included production of 940 kg of agglomerates, seamless loading of the columns, irrigation at above design rates with no degradation of flow and rare earths recovery in line with expectations.