Te(Ⅳ)反應(yīng)動(dòng)力學(xué)
(中南大學(xué) 冶金科學(xué)與工程學(xué)院，長(zhǎng)沙 410083)
摘 要: 以鹵素離子(Cl−、Br−、I−)為催化劑，對(duì)SO2還原Te(Ⅳ)反應(yīng)動(dòng)力學(xué)進(jìn)行研究。結(jié)果表明：在高濃度硫酸體系中，鹵素離子(Cl−、Br−、I−)的濃度為0.3 mol/L，SO2流量為18 L/h，溫度為90 ℃，Cl−、Br−和I−的反應(yīng)時(shí)間分別超過(guò)60、10、10 min時(shí)，Te(Ⅳ)還原率均為97%。以Cl−和Br−為催化劑時(shí)，還原產(chǎn)物為單質(zhì)碲；I−為催化劑時(shí)，還原產(chǎn)物為T(mén)eI。Cl−催化還原Te(Ⅳ)動(dòng)力學(xué)表明，反應(yīng)速率與Te(Ⅳ)濃度的成正比，該化學(xué)反應(yīng)屬于準(zhǔn)一級(jí)反應(yīng)。反應(yīng)活化能受Cl−濃度的影響，當(dāng)Cl−濃度為0.1和0.3 mol/L時(shí)，其活化能分別為44.871和36.714 kJ/mol。
關(guān)鍵字: 碲；鹵素離子；催化；還原；動(dòng)力學(xué)
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
