Mineralogical and geochemical study of rare earth elements from a silicate deposit

摘要

The leachability of the rare earth elements (REE) from the Kipawa deposit, a Heavy REE (HREE) mine project of Matamec resources, was investigated in order to predict their geochemical behavior and to evaluate the factors controlling the REE mobility in ambient conditions. All lithologies of the deposit, including ore and waste rocks, were sampled, characterized using automated SEM-EDS mineralogy, and submitted to kinetic testing using weathering cells in order to investigate their REE leaching potential. All leachates showed a neutral to alkaline pH (7.0 to 9.5) and alkalinity values between 10 and 173 mg CaCO_3/l. The REE concentrations leached from the materials are all below 15μ.g/L. Works are underway (i.e. thermodynamic equilibrium calculations) to determine the control factors of the REE release in the leachates.