Investigation of dissolution kinetics of zinc from smithsonite in 5-sulphosalicylic acid solution

The dissolution kinetics of smithsonite was investigated using 5-sulphosalicylic acid solution as leaching agent. The effects of several experimental parameters on the dissolution of smithsonite were investigated and a kinetic model was developed to represent these relationships. The dissolution rate increased with increasing solution temperature, concentration and stirring speed as well as with decreasing particle size. The dissolution was controlled by the shrinking core model for the surface chemical reaction. The activation energy of the dissolution process was determined to be 44.42 kJ mol(-1). The rate of the reaction based on shrinking core model can be expressed by a semi-empirical equation as: 1-(1-x)(1/3)=[k(0)(C)(0.692)(r(0))(-0.946)(SS)(1.250)exp(-44.42/RT)]t. 5-Sulphosalicylic acid solution can therefore be used as an effective leaching agent for zinc extraction from smithsonite.