A South African miner has produced an ‘exceptionally pure’ mixed rare earth carbonate (MREC) from waste.

Rainbow Rare Earths produced the MREC using a bespoke process involving continuous ion exchange and a series of precipitation steps at its laboratory in Gauteng, reports Engineering News.

‘This purified product delivers a mixed rare earth carbonate averaging >55% total rare earth oxides (TREO) across multiple test samples/campaigns, considerably exceeding the rare earth industry’s typical refinery specification of >42% TREO,’ the company said.

‘The West is finally recognising the importance of REE [rare earth elements], used in permanent magnets vital to the functionality of many of the products that underpin 21st-century society, as well as to emerging and advanced technologies,’ Rainbow Rare Earths CEO George Bennett said.

The company’s project involves processing phosphogypsum from a plant in Phalaborwa, Limpopo province.

Bennett said the lab results represented ‘significant progress’ for the company’s Phalaborwa project, ‘confirming the potential to become a very low-cost producer of light and heavy REE and one of the highest-margin projects in development globally. They also validate our decision to finalise our flowsheet test work in-house and demonstrate that we have developed the expertise to address REE extraction and separation in a highly efficient manner’.

9 September 2025
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