Cobalt recovery from Zambian slags

Cobalt is one of the most important critical metals which could be potentially extracted from the old metallurgical slags in the Zambian Copperbelt. The slags from Luanshya, the oldest mining and smelting site in the Copperbelt, contain up to 5990 ppm Co (median: 2370 ppm). The detailed mineralogical investigation combined with the sulfuric acid leaching simulating hydrometallurgical recovery indicated that up to 67% of Co can be extracted from slag in a short period of time (24 h). However, despite the dramatic increase of Co prices on the global market, its recovery from the Luanshya slags appears to be non-economical due to the high costs of the mechanical and chemical processing of the slag materials. The paper is freely available via open access:

Ettler V., Mihaljevič M., Drahota P., Kříbek B., Nyambe I., Vaněk A., Penížek V., Sracek O., Natherová V. (2022): Cobalt-bearing copper slags from Luanshya (Zambian Copperbelt): Mineralogy, geochemistry, and potential recovery of critical metals. Journal of Geochemical Exploration 237, 106987. (DOI)