The removal of cobalt from zinc electrolyte has been a focus of electrometallurgical research for over 20years. This survey reviews the literature on cobalt cementation as well as zinc electrowinning and hydrogen evolution in the interest of characterizing the factors which are important in cobalt cementation by zinc dust and developing an improved purification process. The effect of speciation, the solubility of zinc hydroxide and zinc sulfate, temperature, pH, and the concentrations of reacting species, impurities, and catalytic agents are all investigated.