(1. 武漢科技大學(xué) 鋼鐵冶金及資源利用教育部重點(diǎn)實(shí)驗(yàn)室，武漢 430081；
2. 湖北金洋冶金股份有限公司，谷城 441705)
摘 要: 碳酸鹽轉(zhuǎn)化工藝作為濕法回收廢鉛膏的關(guān)鍵步驟具有重要的研究意義。在對(duì)廢鉛膏組分分析的基礎(chǔ)上，采用碳酸鹽轉(zhuǎn)化方法對(duì)比探討同一條件下不同轉(zhuǎn)化劑的脫硫效果，對(duì)轉(zhuǎn)化產(chǎn)物進(jìn)行XRD表征；同時(shí),探討(NH4)2CO3脫硫過(guò)程的動(dòng)力學(xué)機(jī)理。結(jié)果表明：轉(zhuǎn)化脫硫率從大到小的順序?yàn)镹a2CO3、(NH4)2CO3、NH4HCO3，以(NH4)2CO3和NH4HCO3作為脫硫劑，PbSO4能被轉(zhuǎn)化生成PbCO3，而采用Na2CO3轉(zhuǎn)化脫硫時(shí)，產(chǎn)物中存在NaPb2(CO3)2OH雜質(zhì)物相。以(NH4)2CO3作為脫硫劑的最佳工藝條件：(NH4)2CO3濃度0.50 mol/L，反應(yīng)溫度50 ℃，反應(yīng)時(shí)間60 min，攪拌速度500 r/min，液固比5:1，在最佳工藝條件下，脫硫率可達(dá)95.66%。PbSO4在(NH4)2CO3溶液中的轉(zhuǎn)化服從收縮核模型，過(guò)程反應(yīng)速率受擴(kuò)散控制，計(jì)算出表觀活化能為16.471 kJ/mol，并最終建立了該脫硫過(guò)程的動(dòng)力學(xué)方程式。
關(guān)鍵字: 鉛膏；碳酸鹽轉(zhuǎn)化；脫硫率；XRD表征；反應(yīng)動(dòng)力學(xué)
（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. XRD characterization results of different transformation products show that PbSO4 can be transformed into pure PbCO3 through (NH4)2CO3 and NH4HCO3. However, the transformation product contains impurity phase NaPb2(CO3)2OH after being desulfurized by Na2CO3. The optimum processing conditions using (NH4)2CO3 as transforming agent were also detected and determined as follows: c(NH4)2CO3=0.5 mol/L, reaction temperature 50 ℃, reaction time 60 min, stirring speed 500 r/min, L/S=5:1, more than 95.66% of PbSO4 was transformed in optimum condition, and kinetics mechanism of desulfurization process by (NH4)2CO3 was discussed. The results indicate that 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 was established.
Key words: lead paste; carbonate transformation; desulfurization rate; XRD characterization; reaction kinetics
