Potential Enrichment of Scandium in Bauxite Deposit for the Emerging Green Technology Needs

Abstract

Scandium (Sc) becomes one of critical raw materials as principal uses are now in the production of scandium-aluminum alloys and also in Solid Oxide Fuel Cells (SOFCs). Scarcity of scandium resources has led the urgency to discover new potential sources of scandium to meet the supply and demand. One of the possible sources of scandium is from bauxite deposit. Tayan area is part of West Kalimantan laterite belt with the potency for scandium resources in Indonesia as a result of the altered granitoid rocks, namely bauxite. This study presents integrated geological and modes of occurrences study to elucidate the potential enrichment of scandium in the study area including through several laboratory analyses: petrography, XRD, XRF, ICP-MS, and SEM-BSE-EDS. Our study concludes that the concretion textures of bauxite samples are dominated by Fe and Al oxide-hydroxide. The ore is composed of gibbsite and goethite. The result of scandium concentration analysis is equal to 50.9 ppm. Systematic SEM–EDS mapping confirms the presence of scandium as mainly from substitution of Fe3+ and Al3+ by Sc3+. Sc is hosted in goethite, where Sc3+ substitutes Fe3+ in goethite crystal lattice. Sc3+ also substitutes Al3+ in gibbsite crystal lattice. Understanding the enrichment in which scandium occurs in bauxite deposit will hopefully open the new possibility to meet the needs for critical materials for green technology development.