Solvent extraction of cobalt at a glance
There are a variety of treatment options for metal recovery that utilize physical, chemical and electrochemical techniques such as chemical precipitation, solvent extraction (SX), ion exchange (IX), oxidation-precipitation and electrowinning. The present paper covers a number of cobalt solvent extraction and recovery methods and some critical comments are given in each case. The solvent extraction method is regarded as the main processing route and is focused on it extensively for its key role in the cobalt extraction industry. General cobalt extractants have been discussed and the common advantages/disadvantages of SX-based plants and developed methods like CSIRO DSX process have been listed.
1. Introduction
Cobalt is one of the metals of high economic and strategic importance, largely because of its wide range of applications and dwindling supplies. Several hydrometallurgical processes have been developed and used to extract cobalt from various sources. Secondary cobalt is recovered from spent catalysts, alloy scraps, zinc plant residues, sludges, dusts, etc. In all cases, cobalt is associated with some other impurities such as Cu, Ni, Fe, Mn, Ca, etc.; depending on the source. The hydrometallurgical processing is very effective for treating such materials because it can control...