Recovery of Some Critical Raw Materials from Processing Waste of Feldspar Ore Related to Hydrothermally Altered Granite: Laboratory-Scale Beneficiation

Abstract

Feldspar for ceramic/glass industries requires sufficiently low content of harmful colourants (Fe-, Ti-, Mn-bearing mineral phases). Hydrothermally altered albite-rich granites are increasingly used as feldspar raw material nowadays; however, they are often marked by increased content of colourants, which must be removed during the processing of feldspar ore. Parallel to the content of colourants, these phases show enrichment in some critical raw materials (CRMs), specifically of Nb, Ta, and Li. In the current study, the laboratory trials focused on the possibility of reprocessing of waste generated during basic magnetic separation of feldspar ore. Major aim of these trials was to search for a processing scheme that would allow for obtaining of mineralogically homogeneous fractions, part of which could be utilised as a source of CRMs. According to the results, combination of gravity, magnetic and heavy liquid separation is highly effective in obtaining of desirable concentrates. Feldspar ore processing waste thus presents potential source of CRMs; however, semi-industrial and full-scale trial must follow in order to prove the economic and environmental suitability of the suggested processing scheme.