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 reach91.43%.
Study of the extraction of gold(III) in aqueous hydrochloric acid media by the phosphine oxide Cyanex 925
Abstract The extraction of gold(III) from hydrochloric acid solutions by means of the phosphine oxide Cyanex 925 was studied as a function of different variables: equilibration time, temperature, organic diluent, and concentration of gold, Cyanex 925, HCl, etc.; the system is selective with respect to the extraction of a number of metals. Gold(III) equilibrium loading isotherms were also obtained at 20°C. Experimental data were treated numerically showing that gold extraction can be explained assuming the formation of a complex with the general stoichiometry: HAuCl 4 L 2 , where L represents the extractant. For the extraction reaction log K ext o = 8.1. The stripping of gold from loaded organic phases can be achieved with water. Data on the extraction of HCl by Cyanex 925 are also presented.
Study of gold (III)-HCl-amine Alamine 304 extraction equilibrium system
Abstract The extraction of gold (III) from hydrochloric acid solutions using solutions of the tertiary amine Alamine 304 in xylene was studied as a function of several variables, such as the hydrochloric acid concentration and ionic strength of the aqueous solution. The extraction of hydrochloric acid by Alamine 304 in xylene has also been studied. A mechanism for the extraction of gold (III) is suggested from the results obtained.