Modern Mining August 2021

RARE EARTHS

comparison, Rainbow’s Gakara project in Western Burundi pro- duces a high-grade mineral concentrate, which has been sold to China for further downstream beneficiation and processing, so realising approximately 30% of the contained rare earths metal oxide value. “The traditional flowsheet developed by Sasol, on the other hand, would produce a mixed rare earth carbonate, realising between 60 and 65% of the contained metal oxide value, com- pared to the 100% of the metal oxide value we would achieve by going further downstream to produce separated, individual oxides as a per the enlarged PEA scope of work.” Bennett expects Capex and Opex savings compared to the initial traditional flow sheet to produce a mixed rare earth carbon- ate for further processing in a dedicated separation facility. Only the high value rare earths (dysprosium, terbium, neodym- ium and praseodymium), which represent 95% of the Phalaborwa rare earths basket value, will be separated and recovered. This will enable the company to capture the full benefit of additional value from downstream processing without superfluous capital and operating expenditure which would be needed to separate all the individual rare earth elements present in the stacks. The outcome of a successful trade-off study will enable Phalaborwa to deliver the increased value of the separated rare earth oxides through a single, low capital-intensity processing plant at the project site. “Owing to the unique nature of Phalaborwa, we are already able to progress to the downstream beneficiation process by

The Sasol Carbonate pilot plant produced 3 t of a cerium-depleted, mixed rare earth carbonate and a cerium oxide.

18  MODERN MINING  August 2021