Geochemical characteristics of REE-enriched weathered anorthosite complex in Hadong district, South Korea

The mineralogy and geochemistry of the weathered intercumulate-type anorthosite complex in Hadong district South Korea were investigated as a prospective area for rare earth resource exploration. In this area, gabbroic was intruded by rare-earth elements yttrium (REE)-bearing dioritic pegmatites (av. 242 ppm), which caused REE-enriched Fe–Ti orebody accumulation 857 ppm) near pegmatites. REE-bearing minerals, such allanite, cerite, xenotime, identified from pegmatite orebody, had undergone various degrees weathering. total REE (?REE) kaolin minerals-bearing clay fractions increased compared to those whole rocks. When treated with ammonium-salt solvents different pH values, that is, 4.6 (NH4Cl(aq)), 5.0 ((NH4)2SO4(aq)), 7.8 (NH4CO3(aq)), 81%, 73%, 70% exchangeable recovered respectively. contrast, minerals-deficient separated ores, less than 10% after treatment, regardless solvent species. Therefore, occurrence primary minerals parent rock, formation fractions, extraction rate seem be crucial securing ion-adsorption type resources.