Development of Antagonistic Solvent Extraction Systems for Selective Separation of Copper, Cobalt, and Nickel in Ammoniacal Solution

Selective separation of copper, cobalt, and nickel from ammoniacal solution using antagonistic solvent extraction (SX) systems has been developed. Copper was first selectively extracted using a combination of LIX 84-I and TBP. Subsequently, cobalt was separated from nickel using a combination of PC88A and Alamine 336. Effects of parameters that were investigated include the total ammonia, initial metal concentration, extractants molar ratio, total extractant concentration and phase ratio. The results show that antagonistic interaction of each combination was suitable for selective separation of copper and cobalt, leaving nickel in the ammoniacal solution for further processing. The two-stage antagonistic SX method is simple and promising for further appropriate treatment steps, and can be regarded as the basis for a sustainable metal separation process.