Leaching kinetics of tellurium-bearing materials in alkaline sulfide solutions

Leaching of tellurium from tellurium-bearing materials is of significant importance. A novel alkaline sulphide leaching process for tellurium-bearing materials was developed. It was found that 94.92% of tellurium and 95.70% of antimony were extracted under optimum conditions: 200 g/L of Na2S concentration, 80 degrees C of temperature, 10:1 mL/g of L/S and 60 min of leaching time. The kinetic data for the dissolution of tellurium and antimony followed the Avrami equation. The calculated activation energies indicated that tellurium dissolution was controlled by the mixed regime of both the diffusion and chemical reaction, while antimony dissolution was controlled by chemical reaction.