Effect of diluents on the extraction and separation of Fe(III) and Cu(II) from hydrochloric acid solutions using N,N,N′,N′-tetrabutyl succinamide

The performance of extraction and stripping of Fe(III) using N,N,N′,N′-tetrabutyl succinamide (TBSA) in different diluents from hydrochloric acid solutions was investigated. The effects of hydrochloric acid concentration, extractant concentration and temperature on the extraction of Fe(III) were studied. The extraction ability of TBSA in different diluents follows the order: kerosene/octanol(v:v = 7:3) < cyclohexane < toluene. The extraction distribution ratio increases with an increase in hydrochloric acid concentration and extractant concentration. The extraction reaction is exothermic and the extraction distribution ratio of Fe(III) with TBSA decreases gradually with increasing temperature. The composition of the Fe(III) extracted species was obtained. The partition of Cu(II) was also investigated and the separation factor of Fe(III) relative to Cu(II) is nearly 140 under the studied conditions, which indicates that TBSA is a good extractant for the separation of Fe(III) from CuCl2 liquor in copper hydrometallurgy.