Separation and Recovery of Zinc and Cobalt from Zinc Plant Residue by Alkali Leaching

Abstract

Zinc plant residue (55.59% zinc content, 0.132% cobalt content) contains a variety of valuable metals, including cobalt, and its abundance is even higher than the abundance of some cobalt ores. In this study, the main influencing factors for the separation of zinc and cobalt by alkali leaching were studied, including sodium hydroxide concentration, reaction temperature, reaction time, solid–liquid ratio (A/S), agitation speed, etc. With an optimal condition of sodium hydroxide concentration 2.5 mol/L, liquid–solid ratio 20/1 (mL/g), reaction time 40 min, reaction temperature 30 °C, zinc leaching rate reached 96.33%, and cobalt leaching rate is less than 10%, the purpose of the separation of cobalt and zinc was initially achieved.