Solvent extraction (SX) is one of the most important separation processes in hydrometallurgy. Solvent or liquid liquid extraction is based on the principle that solute can distribute itself in a certain ratio between two immiscible solvents. Solvent extraction becomes a popular separation technique to recover metals because of its elegance, simplicity, speed and applicability to both trace and macro amounts of metal ions. Recovery of Cu, Co, Zn, U, Mo, W, V, Zr, Hf, Nb, Ta, rare earths, Ga, Ge, the platinum group of metals (PGMs) utilizes SX in hydrometallurgical processing.

For Example, Copper Solvent Extraction 
After the ore leachate is extracted, a part of the copper ions are transferred to the extractant, and the residual water is returned to the leaching agent after acidification. The extractant loaded with copper ions is stripped by sulfuric acid solution, and the copper ions are transferred to the water phase. The copper sulfate solution is electrolytically produced to produce copper plates.