(1. 武汉科技大学 钢铁冶金及资源利用教育部重点实验室，武汉 430081；
2. 湖北金洋冶金股份有限公司，谷城 441705)
摘 要: 碳酸盐转化工艺作为湿法回收废铅膏的关键步骤具有重要的研究意义。在对废铅膏组分分析的基础上，采用碳酸盐转化方法对比探讨同一条件下不同转化剂的脱硫效果，对转化产物进行XRD表征；同时探讨了(NH4)2CO3脱硫过程的动力学机理。结果表明：转化脱硫率从大到小依次为Na2CO3、(NH4)2CO3、NH4HCO3，以(NH4)2CO3和NH4HCO3作为脱硫剂，PbSO4转化生成PbCO3；而采用Na2CO3转化脱硫时，产物中存在NaPb2(CO3)2OH杂质物相。以(NH4)2CO3作为脱硫剂的最佳工艺条件是(NH4)2CO3浓度0.50 mol/L，反应温度50 ℃，反应时间60 min，搅拌速度500 r/min，液固比5:1，在此最佳工艺条件下脱硫率可达95.66%。PbSO4在(NH4)2CO3溶液中的转化服从缩核模型，过程反应速率受扩散控制，计算出表观活化能为16.471 kJ/mol，并最终建立了该脱硫过程的动力学方程式。
关键字: 铅膏；碳酸盐转化；脱硫率；反应动力学
（1. Key Laboratory for Ferrous Metallurgy and Resources Utilization, Ministry of Education, Wuhan University of Science and Technology, Wuhan 430081, China;
2. Hubei Jinyang Metallurgical Incorporated Co., Ltd., Gucheng 441705, China）
Abstract:Carbonate conversion process has important research significance as the crucial step of recovering spent lead paste via hydrometallurgical methods. Based on the analysis of lead paste component from spent lead-acid batteries, the desulfurization efficiencies of different conversion agent in the same condition was determined as follow from high to low: Na2CO3, (NH4)2CO3, NH4HCO3. The transformation products were characterized by XRD. The kinetics mechanism of desulfurization process by (NH4)2CO3 was discussed. The results show that PbSO4 can be transformed into pure PbCO3 through (NH4)2CO3 and NH4HCO3. However, the transformation product desulfurized by Na2CO3 contains impurities phase NaPb2(CO3)2OH. The optimum processing conditions using (NH4)2CO3 as transforming agent are also detected and determined as follows: c((NH4)2CO3) of 0.5 mol/L, reaction temperature of 50 ℃, reaction time of 60 min, stirring speed of 500 r/min, L/S of 5:1, more than 95.66% of PbSO4 is transformed in this optimum condition. The apparent activation energy is calculated as 16.471 kJ/mol and the reaction obeyed shrinking-core model based on the diffusion controlled, as well as the general equation of kinetics of the desulfurization process is established.
Key words: lead paste; carbonate transformation; desulfurization rate; XRD characterization; reaction kinetics
