Recent trends and current practices for secondary processing of zinc and lead. Part Ⅰ:lead recovery from secondary sources

摘要

Implementation of stricter environmental laws and economic reasons has forced all the metallurgical industries to go for eco-friendly technologies to produce metal and other related products. However, generation of wastes is an integral part of metallurgical industries. If the wastes/residues are hazardous in nature, they generally have to be treated or/and disposed of in safe and designated dumping sites. If these wastes/residues are non-hazardous in nature, then they may be suitable for use as secondary raw material to recover metals such as lead, cop-per etc., which are in growing demand all over the world. The processing of lead secondaries is important because of their relative high metal content, as well as the low energy and cost involved in recovering the metal. This paper mainly focuses on the current practices and recent trends in the secondary processing of lead. Various processes, particularly hydrometal-lurgical ones, already developed or in the development stages, are discussed. Attempts made by various Council of Scientific and Industrial Research (CSIR) Laboratories including the National Metallurgical Laboratory (NML) and industries such as Binani Zinc to develop eco-friendly processes for the recovery of lead from secondary raw materials are also described.