Por: Álvaro Ordoñez Núñez, consultor técnico y Edmundo Alfaro Delgado, docente Pontificia Universidad Católica del Perú.

Abstract

The presence of rare earth or Rare Earth Elements (REE) and alkali metals (Rb, Cs and Li), as strategic elements, are of great interest in the world due to their use in new technologies.

Geological prospecting work and reports carried out by Ingemmet in recent years have shown the presence of these strategic elements in the southern part of the country. Therefore, this paper aims to present a preliminary investigation with minerals from the southwestern zone of the Arequipa region.

Research was carried out on treatment processes of mineral samples from that area with the objective of identifying recovery methodologies for those elements. Two methods were tested:

ν Direct acid leaching, based on REE leaching in ion-adsorbed clays.

ν Conventional combined chloride roasting-acid leaching treatment.

Test results indicated that REE can be extracted by acid leaching assisted with chloride ions and hydrogen peroxide; not so the alkali metals which showed lower extractions. However, the alkali metal extractions with the combined process were higher than the acid leach assisted extractions.

Regarding lithium, the low lithium content in the area suggests that this is a rare earth area and not a lithium area. This study has focused on the extraction of Rb and Cs, as well as REE.