摘要
铅酸电池废旧铅膏的回收问题一直是当前科学工作者关注的重要问题,同时废旧铅膏中硫酸铅作为最难处理的成分之一,其具体的固相电解还原过程可行性和作用机理尚不明确。从废旧铅膏的固相电解还原为出发点,着重研究硫酸铅的固相电解还原机理和实际可行性。采用循环伏安曲线在铅电极表面阳极氧化形成硫酸铅膜,利用线性扫描伏安和恒电位阶跃方法研究硫酸铅膜在40℃、200g/L的(NH4)2SO4溶液中的阴极还原过程。结果表明,硫酸铅电解还原过程遵循扩散控制下的三维瞬时形核与生长机理,计算得到对应的交换电流密度为2.753×10^-9 A/cm2,表观传递系数为0.314 7。模拟硫酸铅在200A/m2电流密度下的固相电解试验。结果表明电解产物中铅元素质量分数占比为97.2%。即使在还原后期有析氢反应发生,电流效率仍可达到85.57%,对应的每吨硫酸铅固相电解能耗为609.6kW·h。
The recovery of waste lead paste(WLP)from lead-acid batteries has always been an important issue for scientists at present.The lead sulfate in WLP is one of the most difficult components to deal with at the same time because the feasibility and effect mechanism of specific solid-phase electrolytic reduction process are still unclear.With the solid-phase electrolysis reduction of WLP as the starting pointing,this paper mainly focuses on the solid-phase electrolytic reduction mechanism and practical feasibility of WLP.A cyclic voltammetry curve was used to form a lead sulfate film on the surface of lead electrode,and the cathode of the lead sulfate film in 200 g/L(NH4)2 SO4 solution at 40°C was studied by linear sweep voltammetry and potentiostatic step method.The results show that the electrolytic reduction process of lead sulfate follows the three-dimensional instantaneous nucleation and growth mechanism under diffusion control,the corresponding exchange current density is calculated to be 2.753×10^-9 A/cm^-2,and the apparent transfer coefficient 0.314 7.The solid-phase electrolysis experiment of simulated lead sulfate at a current density of 200 A/m2 showed that the mass fraction of lead in the electrolysis product accounted for 97.2%.Even if there is hydrogen evolution reaction in the late stage of reduction process,the current efficiency could still reach 85.57%,and the corresponding energy consumption solid phase electrolysis is 609.6 kW·h per ton lead sulfate.
作者
戴富书
黄惠
何亚鹏
郭忠诚
DAI Fushu;HUANG Hui;HE Yapeng;GUO Zhongcheng(Faculty of Metallurgical and Energy Engineering,Kunming University of Science and Technology.Kunming 650093,China;Kunming Hendera Science and Technology Co.Ltd,Kunming 650106,China)
出处
《有色金属工程》
CAS
北大核心
2019年第10期44-51,共8页
Nonferrous Metals Engineering
基金
国家自然科学基金资助项目（51504111）
中国博士后科学基金资助项目（2018M633418）
云南省应用基础研究计划项目（2019FD066）~~
关键词
硫酸铅
电化学还原
阴极还原动力学
固相电解
废铅膏回收
lead sulfate
electrochemical reduction
cathode reduction kinetics
solid-phase electrolysis
recovery of waste lead paste
作者简介
戴富书(1992-),男,硕士研究生,主要从事废铅酸蓄电池回收方面的研究;通信作者:黄惠(1976-),教授.主要从事湿法冶金、冶金物理化学领域研究。
