MAXIMIZING THE USE OF HYPER- AND ULTRA-SPECTRAL TECHNIQUES FOR PROSPECTING RARE-EARTH ELEMENTS IN BRAZIL

• Grant number: 25/07515-3
• Support Opportunities: Regular Research Grants
• Start date: September 01, 2025
• End date: August 31, 2028
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Geology
• Principal Investigator: Diego Fernando Ducart
• Grantee: Diego Fernando Ducart
• Host Institution: Instituto de Geociências (IG). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Associated researchers: Carlos Roberto de Souza Filho ; CLAUDIO GERHEIM PORTO ; David Jozef Cornelius Debruyne ; Francisco Sergio Bernardes Ladeira ; Ignacio Gonzalez-Alvarez ; NILSON FRANCISQUINI BOTELHO ; Raphael Bianchi Hunger

Abstract

Rare earth elements (REEs) are indispensable in clean-energy technologies yet remain in limited and geographically concentrated supply. The main Brazilian REE deposits occur in cratonic areas (primary and secondary deposits) and marine placers along the coast (secondary deposits). Primary deposits are related to alkaline-carbonatitic complexes and alkaline granitic rocks, whereas secondary deposits are weathering products of primary deposits, such as ion-adsorption clay and marine placer deposits. Reflectance spectroscopy and hyperspectral imaging in the visible-near infrared (VNIR), short-wave infrared (SWIR), and Thermal Infrared (TIR) ranges are non-destructive technologies that offer cost-effective solutions by rapidly assessing mineralogical ore grade and prospection. This project will develop a multi-scale reflectance spectroscopy and hyperspectral imaging workflow (VNIR-SWIR-TIR) integrated with geochemical (LA-ICP-MS, SEM-EDS, microprobe) and mineralogical (XRD) methods. It aims to characterize key REE minerals in selected deposits, identify and quantify REE concentrations, and establish REE mineral models by analyzing reference deposits such as Serra Verde, Caldeira, Sossego, and Madeira. The project will refine the understanding of Brazilian REE deposit enrichment models, improve prospectivity strategies, and produce spectral reference database libraries for REE mineralogy, ultimately leading to enhanced REE exploration in Brazil. (AU)