Resumen de Modelos de especiación solubilidad de tierras raras en las soluciones termales de los sistemas de Caldas de Boí, Artiés, Tredós y Les (Pirineo Central; Lérida)
Belén Buil Gutiérrez, S. García Sanz, Marceliano Lago San José, Enrique Arranz Yagüe
The behaviour of rare earth elements (REE) in thermal waters from the Caldas de Bof, Artiés and Les geothermal systems (Central Spanish Pyrenees) has been modelled by means of spedation-solubility calculations. The model shows a marked tendency to complexation of the lanthanides,increasing this tendency at higher temperatures. The dominant complex species for light-REE (Lato Nd) is LnOH° at deep levels of the geothermal system, varying progressively to LnCOf+ athigher levels, near the surface. The spéciation of heavy-REE (Sm to Lu) is nearly invariable,being Ln(OH)4 the main species throughout the entire flow path. The spéciation of the lanthanidesis thus strongly dependent of temperature, being the REE-hydroxyl complexes dominant at the reservoir; the REE-carbonate complexes are formed, specially for the light-REE, as temperature lowers (and pH increases), during the ascent of the waters.
