Overview of cobalt resources and comprehensive analysis of cobalt recovery from zinc plant purification residue- a review

With the rapid development of electric vehicles and 5G network technology, cobalt, a potentially critical metal, is widely used in batteries. Considering the supply risk of cobalt, which is approaching the near-critical level, it is necessary to comprehend the status of cobalt resources and analyze the potential recycling of cobalt from metallurgical wastes and spent cobalt compounds. In this paper, the existing types, distribution and reserves of cobalt resources are first introduced. Subsequently, the importance of recovering cobalt from metallurgical wastes is discussed, and the zinc plant purification residue (ZPPR) is introduced in particular. Recovering cobalt, zinc, cadmium, and other valuable elements from ZPPR is significant in addressing problems associated with these solid wastes. Metallurgical processes for the separation and recovery of zinc and cobalt from ZPPR are investigated in detail in subsequent sections, which include selective acid leaching, oxidation-precipitation, ammonia-ammonium sulfate leaching, and solvent extraction. Their mechanisms and performance are also reviewed. The results suggest that further research is required to improve the separation and extraction selectivity and efficiency, and also for the development of high-value utilization of ZPPR and a more efficient method for extracting cobalt from zinc leaching solution.