Abstract:Reduction reaction of tellurium in Pt/Pd-replaced solution was investigated with sulfur dioxide as reductant. The results show that tellurium reduction rate is 99% above with Te content in raw-tellurium powder of 90% above under the conditions including Cl- concentration of 1.0 mol/L by adding hydrochloric acid, reaction temperature of 75 ℃, and aeration of SO2 gas of 2 h. Reduction of Te rises with increase of reaction duration, temperature, and acidity of solution. Reduction reaction of Te is in accordance with pseudo-first-order reaction controlled by kinetics. Mechanism model for reduction reaction between SO2 and Te is proposed, in which Cl- and H are both regarded as catalytic species during transformation from tellurous acid to tellurium tetrachloride.