Estudio del fraccionamiento y la especiación de REE en ambientes ácidos ecuatorianos mediante experimentos de laboratorio

Abstract

Rare earth elements have frequently been used as environmental tracers. However, its current importance lies in the market added value hat elements such as Eu, Tm and Lu have due to their use in the technological industry. Hence, numerous studies are lending special interest in their behavior in acidic environments, where these elements experiments fractionation processes. Thus, this work aims to characterize the content in REE in AMD (Acid Mining Drainage) of the Ecuadorian mining area Zaruma-Portovelo during its process of neutralization by means of treatment that allow understanding this complex evolution system. The results show a clear association between the total concentration of REE and the changes in pH conditions that occur in the water treatment. The convex patterns of REE at the beginning were evolving towards flat or sawed patterns clearly indicative of the fractioning processes in favor of the solid phases. In addition, the modelling of aqueous phases has allowed us to distinguish an initial fractionation model similar to that proposed in the literature in favor of Fe and Al oxyhydroxides at acidic pH that evolved throughout the treatment towards a more complex model of carbonated and/or phosphates phases as the main sink of REE when the pH is higher than 6.