Te(Ⅳ)反应动力学
(中南大学 冶金科学与工程学院，长沙 410083)
摘 要: 以卤素离子(Cl−、Br−、I−)为催化剂，对SO2还原Te(Ⅳ)反应动力学进行研究。结果表明：在高浓度硫酸体系中，卤素离子(Cl−、Br−、I−)的浓度为0.3 mol/L，SO2流量为18 L/h，温度为90 ℃，Cl−、Br−和I−的反应时间分别超过60、10、10 min时，Te(Ⅳ)还原率均为97%。以Cl−和Br−为催化剂时，还原产物为单质碲；I−为催化剂时，还原产物为TeI。Cl−催化还原Te(Ⅳ)动力学表明，反应速率与Te(Ⅳ)浓度的成正比，该化学反应属于准一级反应。反应活化能受Cl−浓度的影响，当Cl−浓度为0.1和0.3 mol/L时，其活化能分别为44.871和36.714 kJ/mol。
关键字: 碲；卤素离子；催化；还原；动力学
Te(Ⅳ)-H2SO4-H2O system
（School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China）
Abstract:The reaction kinetics of Te(Ⅳ) reduced via SO2 were investigated with halogen ions(Cl−, Br− and I−) as catalyst. The results show that the reduction ratios of Te(Ⅳ) in the high concentration system of sulfuric acid are all more than 97% after Te(Ⅳ) is reduced when the reaction times of Cl−, Br− and I− are over 60, 10 and 10 min under the conditions of c(Cl−), c(Br−) and c(I−) of 0.3 mol/L, SO2 flow rate of 18 L/h and temperature of 90 ℃. The reduction product of Te(Ⅳ) is elemental tellurium using Cl− or Br− as catalyst, and the reduction product is TeI using I− as catalyst. The reaction kinetics of Te(Ⅳ) using Cl− as catalyst indicates that the reaction rate is proportional to the concentration of Te(Ⅳ), and this chemical reaction is in accordance with pseudo-first-order reaction. The reaction activation energy is influenced by the concentration of chloride ion. When the concentrations of chloride ion are 0.1 and 0.3 mol/L, the activation energy are 44.871 and 36.714 kJ/mol, respectively.
Key words: tellurium; halogen ion; catalysis; reduction; kinetics
