废铅酸蓄电池铅膏铵法预脱硫过程的动力学分析

Kinetic analysis of pre-desulfurization process with ammonium bicarbonate method from lead paste in waste lead-acid batteries

以废铅酸蓄电池中铅膏为研究对象,开展了用NH4HCO3为脱硫剂对铅膏进行脱硫转化的实验研究。通过分析反应过程中PbSO4转化率随时间的变化关系,考察了搅拌速度、反应温度及NH4HCO3浓度对铅膏脱硫转化的影响;利用固液多相反应的收缩核模型,分析了反应的动力学过程,并计算了反应的表观活化能及表观反应级数。结果表明:在实验选取的条件范围内,提高反应温度、增大NH4HCO3浓度及加快搅拌速度均可以促进铅膏的脱硫转化;表观活化能为9.7 kJ·mol^-1,表观反应级数为0.71,反应过程受内扩散步骤控制。研究结果可为铅膏铵法预脱硫技术能高效、低耗的应用提供参考。

In this study,the lead paste in waste lead-acid batteries was taken as a research object and the experiments on desulfurization and conversion with ammonium bicarbonate(NH4HCO3)were conducted.The effects of the stirring speed,reaction temperature and NH4HCO3 concentration on PbSO4 conversion rate in lead paste were investigated.In addition,the reaction kinetics was analyzed by the shrinking core model of liquidsolid multiphase reaction,and the apparent activation energy and reaction order were calculated.The results showed that within the selected conditions,the desulfurization rate and conversion of lead paste could be promoted by increasing the reaction temperature,the concentration of NH4HCO3,and the stirring speed.Moreover,the apparent activation energy and reaction order were 9.7 kJ·mol^-1 and 0.71,respectively,and the whole process was controlled by the internal diffusion step.This study provided some references for the high efficient and low consumption application of pre-desulfurization technology with NH4HCO3 from lead paste.