Abstract:

Lead acid batteries are widely used in China, and there are some problems in the traditional recovery process, such as environmental pollution, high energy consumption and long recycling process. Therefore, solution synthesis of PbO has attracted people's attention. Based on the solution synthesis of PbO from lead acetate solution and NaOH, two crystal forms of PbO, α?-PbO(litharge) and β?-PbO(massicot), were synthesized by changing the way NaOH was added. The synthetic conditions, intermediate process and mechanism were preliminarily discussed. Lead acetate solution prepared by simulated desulfurization lead paste was used as raw material and the effects of NaOH dosing mode, reaction temperature, reaction time and mole ratio of NaOH to Pb were explored, respectively. The results showed that the intermediate products Pb₃O₂(OH)₂ was synthesized firstly and then decomposed into PbO quickly. A more stable product α?-PbO was synthesized with the participation of exothermic process of NaOH dissolution. Therefore, two crystal forms of PbO, α?-PbO and β?-PbO, could be synthesized by changing the dosing mode of NaOH. The optimized conditions to obtain α?-PbO were as follows: the temperature was 95℃, the NaOH particles quickly mixed with equal mass of deionized water and then added, the molar ratio of NaOH/Pb_{was 2.50, and the mixture was stirred under the given temperature for 20min; The optimized conditions to obtain β-PbO were as follows: temperature of 95℃, adding 50% NaOH solution prepared one day in advance, the molar ratio of NaOH/Pbwas 2.50, and stirring for 20min under the given temperature. This study can provide theoretical reference for the synthesis of α-PBO and β-PBO in liquid phase by wet recovery of waste lead-acid battery.}

Key words: waste lead acid batteries, waste treatment, recovery, synthesis, litharge, massicot

摘要：

铅酸蓄电池在我国有着广泛应用，其传统回收工艺存在环境污染、能耗高、回收流程长等问题。因此，湿法回收液相合成PbO工艺引起了人们的关注。本文基于乙酸铅溶液与NaOH反应液相合成PbO工艺，通过改变NaOH投加方式，合成α-PbO与β-PbO两种晶型的PbO，并对合成条件及反应中间过程和机理进行初步探讨。实验以模拟脱硫铅膏制备的乙酸铅溶液为原料，探究了NaOH投加方式、反应温度、反应时间和NaOH与Pb摩尔比对PbO合成的影响。结果表明，乙酸铅溶液与NaOH反应液相合成PbO时，先生成中间产物Pb₃O₂(OH)₂，Pb₃O₂(OH)₂又快速分解为PbO，NaOH溶解放热过程参与反应会促进Pb₃O₂(OH)₂向常温下更稳定的α-PbO分解转化。因此，通过改变NaOH的投加方式，可以得到α-PbO与β-PbO两种晶型的PbO。α-PbO合成条件为温度95℃，NaOH颗粒与等质量去离子水快速混合后投加，NaOH与Pb摩尔比n_NaOH/n_Pb=2.50，恒温搅拌20min；β-PbO的合成条件为温度95℃，投加提前一天配制的质量分数为50%的NaOH溶液，NaOH与Pb摩尔比n_NaOH/n_Pb=2.50，恒温搅拌20min。该研究可为废铅酸蓄电池湿法回收液相合成α-PbO与β-PbO提供理论参考。

关键词: 废铅酸蓄电池, 废物处理, 回收, 合成, α-PbO, β-PbO