Extraction of Gold from Alkaline Gold Leaching Solution by Tertiary Amine N235 and Phosphine Oxide

Extraction of gold from alkaline gold leaching solution by N₂₃₅-TRPO synergistic system was studied. The effects of the concentrations of Tri-akylphosphine oxide(TRPO)and tertiary amine(N₂₃₅), the initial pH, and the concentration of gold on the extraction of gold and the extraction isotherm were inspected. The ability of extracting other metal elements by this system had been investigated. The effect of alkali concentration on stripping of gold from loaded organic phase had also been studied. The experimental results indicate that the system consisting of 10% N₂₃₅, 10% TRPO gave high extraction yield for gold along with the lesser extraction of silver and copper which are needed to recover. The gold extraction was over 94%, at pH=9~10 and the stripping of gold from loaded organic phase using 0.05mol/L NaOH can reach 91.43%.