中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
Vol. 30 No. 8 August 2020 |
(1. Institute of Environmental Science and Engineering, School of Metallurgy and Environment, Central South University, Changsha 410083, China;
2. Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, Changsha 410083, China;
3. School of Materials Science and Engineering, Central South University, Changsha 410083, China)
Abstract:The reduction kinetics of zinc calcine under a CO atmosphere was evaluated by isothermal reductive roasting in a temperature range of 600-800 °C. The extent of reaction of zinc calcine was measured using thermogravimetry (TG), and the decomposition mechanism of zinc ferrite in zinc calcine was analyzed based on variations in the soluble zinc and ferrous contents. The results indicate that the reaction was controlled by the nucleation of the products, with an apparent activation energy of 65.28 kJ/mol. The partial pressure of CO affected the reaction rate more strongly than the CO intensity (defined as PCO/(PCO+PCO2)). The generation rate of zinc oxide was higher than that of ferrous oxide; therefore, the nucleation of ferrous oxide is the rate-determining step of the reaction.
Key words: reduction kinetics; zinc calcine; zinc ferrite; carbon monoxide