EARTH

[3901-12-12] Leaching of Te-bearing materials in sodium sulfide solution with emphasis on kinetics

○Zhipeng Xu¹, Qinghua Tian¹, Dong Li¹, Xueyi Guo¹ (1. Central South University)

Chairman: Kyoungkeun Yoo （Korea Maritime and Ocean University）, Naoki Hiroyoshi (Hokkaido University)

Keywords:Te-bearing materials, Tellurium, Antimony, Sodium sulfide leaching, Kinetics

A novel method for leaching of Te-bearing materials in sodium sulfide solution is proposed. The influences of Na₂S concentration, leaching temperature, NaOH concentration, liquid to solid ratio and leaching time on the tellurium and antimony were systematically investigated. It was found that 94.92% of Te and 95.70% of Sb were extracted into leaching solution under the optimum conditions: Na₂S concentration 200 g/L, 80 °C of leaching temperature, NaOH concentration 0 g/L, 10:1 mL/g of liquid to solid ratio and 60 min of leaching time. The empirical kinetic model, -ln(1-x) = kt was used to describe the kinetics of tellurium and antimony dissolution in sodium sulfide solution. The calculated activation energies for tellurium and antimony dissolution were 19.4 kJ/mol and 63.5 kJ/mol respectively, indicating that tellurium dissolution was controlled by the interface transfer and diffusion through the product layer and antimony dissolution was controlled by the interface transfer.