Recovery of rare earth elements by elutriation-leaching from the tails of the Caron process

Abstract

The high-tech metals present in the residual tailings from the Caron process in
Cuba revalue these mineral reserves. This research was carried out with the
purpose of evaluating the extraction of the elements Ni, Co, Sc, La, Y, Yb from
the residual tails via elutriation and acid leaching. Leaching was carried out at
atmospheric pressure at 75 °C and 95 °C, and H2SO4 concentration 90 g/L and
120 g/L. For its part, high pressure leaching was carried out at 245 °C and
equal levels of acid. The chemical composition was determined by the Atomic
Absorption technique and by ICP-OES. As a result, the glue sample had an
average chemical composition of: Ni=0,420 %; Co=0,097 %; La=0,000 602 %;
Sc=0,006 010 %, Y=0,000 660 %, and Yb=0,000 550 %. It was determined that
the leaching of the elutriated fine provides greater extraction of rare earth
elements, on average: Ni=31,93 %, Co=41,78 %, La=36,61 %, Yb=21,25 %,
Y=17,35 %, Sc=19,96 %. However, the leaching pressure affects the selectivity
of the extraction of the elements in the fine indistinctly. It was determined that
atmospheric leaching of the fine elutriate provides the greatest economic
benefit.