类铝冶金的废铅膏低温还原清洁炼铅的技术思路

来源期刊：中国有色金属学报2019年第4期

论文作者：刘伟锋 张坤坤 邓循博 张杜超 陈霖 杨天足

文章页码：810 - 821

关键词：铅冶金；铅酸蓄电池；废铅膏；水热转化；低温熔炼

Key words：lead metallurgy; lead acid battery; waste lead paste; hydrothermal conversion; low temperature smelting

摘    要：废铅酸蓄电池是最重要的再生铅资源，通常先拆解再分别回收利用,由于废铅膏中存在大量硫酸铅，使其成为废铅酸蓄电池资源化利用的瓶颈。废铅膏处理传统火法工艺和湿法工艺均是以阴极铅为目标产物，其中火法工艺获得了广泛应用，近些年材料冶金思路则是绕开废铅膏制备阴极铅的过程，用废铅膏直接制备铅酸蓄电池用的铅粉。借鉴铝冶炼工业由铝土矿到氧化铝再到金属铝的工艺思路，本文提出一种基于水热还原转化的废铅膏低温还原清洁炼铅工艺：首先，废铅膏通过硫酸浸煮脱除杂质；其次，浸煮渣在碱和还原剂同时存在下水热处理，使硫酸铅和二氧化铅均转化为氧化铅；最后，低温熔盐中用淀粉还原氧化铅产出金属铅。该工艺为废铅膏处理的工艺改革提供一种新的思路。

Abstract: Waste lead acid battery is the most important renewable lead resource, which is usually dismantled and then recovered separately. Waste lead paste contains lots of lead sulfate, which is a bottleneck for the effective utilization of waste lead acid battery. The conventional pyrometallurgical process and hydrometallurgical process all regard cathode lead as the product, and the former has been widely used. In recent years, material metallurgy aims to directly prepare lead powder for lead acid battery using waste lead paste, which has also been widely studied. Drawing lessons from the idea of aluminum extraction process from bauxite to alumina and aluminum in sequence, a clean lead smelting in low temperature of waste lead paste after hydrothermal reduction conversion was proposed. First, impurities are removed from waste lead paste by leaching in sulphuric acid solution. Then, during the hydrothermal reduction concerting, lead sulfate will be converted into lead oxide with the addition of alkali as conversion agent. At the same time, lead dioxide will be reduced to lead oxide with adding reductant. Final, lead oxide can be reduced to metallic lead at low temperature in molten salt using starch as the reductant. The technology will provide a new idea for the recycle of waste lead paste.