ABSTRACT

Aiming at the pollution problem of low-content SO₂ in non-ferrous metal production industry, the oxidation kinetics of zinc sulfite in the zinc oxide desulfurization process was studied. The concentration change of Zn²⁺, variation of pH, temperature and apparent activation energy in the oxidation process of two ZnSO₃ samples were investigated systematically. The results indicate that the raw material with different crystal water has little effect on the oxidation kinetic of zinc sulfite. The reaction process comprises two stages: the dissolution process and the oxidation process. The zinc ion concentration is linearly rising with the action time during the oxidation process. The pH value rises quickly in the dissolution process and goes down slowly with reaction time in the oxidation process. The process is mainly controlled by a diffusion step and less effected by the temperature. The apparent activation energy E_a obtained for the two samples are 8.662 and 9.645 kJ/mol, respectively. Integrated with the kinetic model, the oxidation rate of zinc sulfite is controlled by the diffusion of HSO₃⁻ and O₂ to the gas–liquid interface.

摘要

针对有色金属生产行业中低含量SO _{2的污染问题，研究了氧化锌脱硫过程中亚硫酸锌的氧化动力学。两种ZnSO 3氧化过程中Zn} ²⁺的浓度变化、pH、温度和表观活化能的变化样本进行了系统的调查。结果表明，不同结晶水的原料对亚硫酸锌的氧化动力学影响不大。反应过程包括两个阶段：溶解过程和氧化过程。在氧化过程中，锌离子浓度随作用时间线性上升。pH值在溶解过程中迅速上升，在氧化过程中随着反应时间缓慢下降。该过程主要由扩散步骤控制，受温度影响较小。两个样品的表观活化能E _a分别为 8.662 和 9.645 kJ/mol。结合动力学模型，亚硫酸锌的氧化速率由 HSO _{3的扩散控制}^-和O ₂到气-液界面。