Separation of copper and zinc cations from each other in aqueous acid sulphate solution using Tri-N-Butyl phosphate (TBP)

Abstract

The separation of copper and zinc cations from each other in aqueous acid sulphate solution using tri-n-butyl phosphate was investigated. The effects of the aqueous Zn²⁺ and Cu²⁺ concentrations, organic phase concentration of tri-n-butyl phosphate (TBP), pH and temperature on the degree of extraction of copper and zinc cations were studied. The loading of Copper and Zinc cations from the aqueous phase into the organic phase were pH dependent, a pH of 5 for copper (11) and pH 7 for Zinc (11) appeared to be most favourable. The respective increased concentrations of Cu²⁺, Zn²⁺ and TBP favored Cu²⁺ and Zn²⁺ extraction. Temperature had little effect. The experimental data suggested that, the separation of Cu²⁺ and Zn²⁺ from each other could be carried out by changing the pH at 32 ± 2°C. The separation of Cu²⁺ from Zn²⁺ is most favourable at pH 5, while Zn²⁺ from Cu²⁺ is most favourable at pH 7. The experimental results also indicate that this method of extraction could be employed to obtain up to 90% of each metal ion from the aqueous mixture.

Keywords: extraction, aqueous phase

Global Journal of Pure and Applied Sciences Vol. 12(1) 2006: 93-97