Control mineralógico sobre la fijación de metales en procesos de oxidación de sulfuros

Abstract

Gossans are the products of intense oxidation of massive sulphide deposits exposed in the surface. In the Filón Sur deposit (Tharsis, Huelva), a detailed petrological and mineralogical study of the gossan has allowed us to establish the distribution and abundance of the main mineral phases in the gossan profile. Among these mineral phases, beudantite is present in the whole profile, although it tends to concentrate tower the lower part, where this mineral can reach up to 40 %. Chemical analyses of beudantite have shown the presence of important amounts of As and Pb in their structure (up to 13 %

As203 and 41% PbO). Taking into account that the content of As and Pb in the original sulphides is very low, beudantite acts as a sink for these two elements during the gossan formation process. This natural mechanism of As and Pb fixation can have important consequences for remediation of areas affected by acid mine drainage