A sulphate solution of cobalt (18.93 g/L Co2+) containing major impurities such as copper (1.35 g/L Cu2+), iron (0.28 g/L Fetot), zinc (0.70 g/L Zn2+) and manganese (4.83 g/L Mn2+) was purified through the solvent extraction method using two extractants; MEXTRAL and D2EHPA for the removal of copper and for the removal in two stages of a zinc-iron-manganese complex respectively. The effects of the solution’s pH, O/A ratio, extraction time and stirring intensity were investigated. The purification extent was enhanced by optimizing these four parameters through Taguchi’s L16 (4^4) experimental. The final solution obtained through sequential extractions showed a reduction in Cu, Fe, Zn and Mn content of 98.7, 97.5, 98.2, and 80.5% respectively. This study showcased the possibility of obtaining high purity cobalt as a precursor for Lithium ion battery applications, representing 49% of its current global use. The coextraction value of cobalt was estimated at 6.2%.
Key words: Purification, MEXTRAL 984N, D2EHPA, cobalt, SX.
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