A review of technologies for the recovery of metals from spent alkaline and zinc–carbon batteries

The main aim of this paper is to review and evaluate the recovery studies and associated technologies for metals from spent batteries. More attention was given especially to the recovery of Zn and Mn from spent alkaline and zinc–carbon batteries. Nowadays, much research work is concentrated on the recovery of Zn and Mn from alkaline and zinc–carbon batteries. Various different metal recovery processes including physical, pyrometallurgical, and hydrometallurgical ones are discussed. Compared to pyrometallurgical methods, hydrometallurgical methods are becoming a well-established and efficient method for recovering metals from raw materials. Although there have been many proposed or currently applied recovery processes, the majority of them are effective only in recovering certain components of spent batteries. Considering the more stringent regulations and cost, environmental protection, and preservation of raw materials issues, effective, economical, and practical recovery technologies are required not only for metal recoveries but also for other components of batteries such as plastic, paper, steel, etc. More research work should be conducted to develop such recovery technologies. In addition, process control and plant optimization studies should also be conducted for more feasible full-scale applications.