Kinetics of sphalerite dissolution by sodium chlorate in hydrochloric acid

The extraction of zinc from a sphalerite concentrate using sodium chlorate as an oxidant in hydrochloric acid solutions was examined. It was determined that stirring speed did not significantly affect zinc extraction compared with other experimental parameters. The dissolution rate increased with increasing sodium chlorate and hydrochloric acid concentrations and temperature, but decreased with increasing particle size. The kinetic Study showed that the dissolution of zinc could be represented by a shrinking core model with surface chemical reaction. The activation energy (Ea) for the dissolution reaction was calculated as 41.1 kJ/mol. (C) 2008 Elsevier B.V. All rights reserved.