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%.
Gold(I) extraction from cyanide media by the primary amine Primene 81R/iso-decanol system
Abstract The extraction of gold(I) from cyanide solutions using the primary amine Primene 81R has been studied taking into account the variables temperature, agitation time, metal and amine concentration and aqueous ionic strength. The results show that gold(I) is extracted by means of a complex with the possible stoichiometric formula: [RNH 3 + Au(CN) 2 − ·3RNH 2 ] org . The infrared spectrum shows that there is no specific interaction between the amine and the cyanide gold complex.
THREE-PHASE EXTRACTION STUDY OF THE TOA-ALKANE / HC1 (Zn2+ or Fe3∗) SYSTEMS 1
ABSTRACT The three-phase extraction systems TOA-n-heptane / HC1, TOA-kerosene / HC1, TOA-kerosene / HCl-ZnCl2 and TOA-kerosene / HCl-FeCl3 have been investigated. The volumes and compositions of the equilibrium phases for these systems have been determined at 298K at a phase ratio of one. In the HC1 extraction system, amphiphilic molecules TOA-HC1 in heavy organic phase (i.e. the third phase or the middle phase) self-assemble into a lamellar structure, and water and alkane are solubilized in polar layers and nonpolar layers respectively. The solubilization capacities are within the saturation value of TOAHCl:H20:n-heptane=l:2:3 (molar ratio). The solubiiizition decreases when the ratio of initial HC1 concentration to initial TOA concentration is less than one and excess acid and water are extracted into the middle phase if initial concentration of HC1 is higher than that of TOA. Zinc and iron are mainly extracted into the middle phase. The metal extraction systems have different phase behavior than the ac...