Characterization of nano-minerals and nanoparticles in supergene rare earth element mineralization related to chemical weathering of granites

Abstract

Ion adsorption-type rare earth element (REE) ore deposits in South China are a major source of heavy rare earth elements (HREE) around the world which are of considerable economic and strategic significance. In these ores, REE is enriched in the clay minerals, specifically kaolinite and halloysite which are derived from their parent granitoid by the weathering process. However, the mechanisms of supergene REE mineralization remain unclear.We investigated the nature and origin of supergene REE mineralization, based on a nano-scale study of a typical REE-mineralized granite regolith profile (ΣREE max = 1201 ppm) in the Dazhou