电镀污泥碳热还原挥发锌、锡和铅的动力学研究

含铜污泥是冶金化工行业的工业废水经过处理后的工业废弃物, 目前已被列入国家危险废物名单, 其中含有铜, 锌, 镍, 锡, 铅等多种有价金属, 为了回收其中的有价金属, 文中研究了电镀污泥碳热还原中锌、锡和铅挥发规律及动力学。通过电镀污泥碳热还原实验可知, 当碳热还原温度提高至1 523 K时, 在该温度下碳热还原60 min, Zn的挥发率可达到96.98%, Sn的挥发率可达到96.24%, Pb的挥发率可达到95.37%, 且高温有利于Zn、Sn及Pb的碳热还原挥发。电镀污泥碳热还原动力学实验结果表明, Mckwan反应方程能较好地描述电镀污泥碳热还原反应体系, Zn、Sn及Pb还原挥发活化能分别为149.50、138.01、132.26 kJ/mol, 电镀污泥碳热还原过程受界面化学反应控制。 

Kinetic of carbothermal reduction of zinc,tin and lead from electroplating sludge

Copper-containing sludge, the industrial waste after treatment of industrial waste water from metallurgical and chemical industries, has been added to the list of the national hazardous wastes. It includes such valuable metals as copper, zinc, nickel, tin, lead. In order to recover these metals, this paper studies the volatilization law and kinetics of carbothermal reduction of zinc, tin and lead by electroplating sludge. According to the experiment, when the carbothermal reduction temperature was raised to 1 523 K, the volatilization rate of Zn, Sn and Pb could reach 96.98%, 96.24% and 95.37% respectively under the condition of carbothermal reduction for 60 mins, and high temperature was favorable for volatilizing Zn, Sn and Pb. The results showed that the reaction system of carbothermal reduction of electroplating sludge could be described by Mckwan reaction equation effectively. The activation energies of Zn, Sn and Pb reduction volatilization were 149.50, 138.01 and 132.26 kJ/mol, respectively. The carbothermal reduction process of electroplating sludge was controlled by interface chemical reaction.