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

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