Pensana Rare Earths says it has successfully produced a neodymium- and praseodymium-rich mixed rare earth carbonate (MREC) from test work currently underway on mineralisation from its Longonjo rare earth project, in Angola.

Industry experts Wood Group and Nagrom, based on test work performed at metallurgical laboratories in Perth, Western Australia, have successfully developed a flowsheet to produce a particularly high-grade MREC, with NdPr comprising 33.5% of the total rare earths content, Pensana said.

This MREC is a much higher-purity and higher-value product and has a much broader market and range of applications than the concentrate product contemplated in Pensana’s prefeasibility study, according to the company. Also, based on information provided by Wood and Nagrom, the specifications of Longonjo’s MREC compare favourably with the main products currently being produced and sold mainly in China.

In the meantime, the pilot plant and metallurgical test work at Longonjo are ongoing with a view to finalising the preferred process route and to providing data for engineering and production cost estimations for the bankable feasibility study (BFS).

A comprehensive update on the BFS will be reported towards the end of the month, with the company explaining that two of the circuits will be required to run for longer to bring the test work results up to the required reporting standards for the study.

“A key feature that the study will report is the potential for the project to be brought online as the first major rare earth mine in over a decade which can also offer a sustainable supply of mixed rare earth carbonate at a time when there is growing concern around the provenance of the rare earth supply chain,” the company said.

Pensana Chief Executive Officer, Tim George, said: “This is an important milestone for the project as it confirms the potential to produce a marketable higher value NdPr rich mixed rare earth carbonate. The market for this carbonate is substantially larger than that of a concentrate and is potentially not limited to China.

“We are now in a position to commence discussions with potential offtake parties in Japan, Korea and Europe in addition to the wide range of potential customers in China.

“Importantly the combination of this value-adding step, with the excellent infrastructure, not least the available hydro-electric power supply, will enable us to develop Longonjo as one of the world’s most sustainable rare earth suppliers on the critical magnet metal supply chain.”

Pensana recently issued a resource upgrade for Longonjo, which outlined measured, indicated and inferred resources of 313 Mt at 1.43% rare earth oxides, including 0.32% NdPr for 4.47 Mt of REO including 990,000 t of NdPr.