(1. 武漢科技大學(xué) 鋼鐵冶金及資源利用教育部重點實驗室，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。在對廢鉛膏組分分析的基礎(chǔ)上，采用碳酸鹽轉(zhuǎn)化方法對比探討同一條件下不同轉(zhuǎn)化劑的脫硫效果，對轉(zhuǎn)化產(chǎn)物進行XRD表征；同時探討了(NH4)2CO3脫硫過程的動力學(xué)機理。結(jié)果表明：轉(zhuǎn)化脫硫率從大到小依次為Na2CO3、(NH4)2CO3、NH4HCO3，以(NH4)2CO3和NH4HCO3作為脫硫劑，PbSO4轉(zhuǎn)化生成PbCO3；而采用Na2CO3轉(zhuǎn)化脫硫時，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是(NH4)2CO3濃度0.50 mol/L，反應(yīng)溫度50 ℃，反應(yīng)時間60 min，攪拌速度500 r/min，液固比5:1，在此最佳工藝條件下脫硫率可達95.66%。PbSO4在(NH4)2CO3溶液中的轉(zhuǎn)化服從縮核模型，過程反應(yīng)速率受擴散控制，計算出表觀活化能為16.471 kJ/mol，并最終建立了該脫硫過程的動力學(xué)方程式。
關(guān)鍵字: 鉛膏；碳酸鹽轉(zhuǎn)化；脫硫率；反應(yīng)動力學(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. 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
