Extraction of trace amounts of gold from hydrochloric acid solutions by cyclic and linear ethers

Extraction of trace amounts of gold-195 and 23 microimpurities by linear polyethers (dibutyl ethers of di-, tri-, tetraethyleneglycol) and macrocyclic polyethers -derivatives of 18-crown-6 from solutions of 1-9 mol/l HCl was studied. cis-Isomer of dicyclohexyl-18-crown-6 and its alkyl derivatives is shown to be the most effective extractant for gold extraction. Coefficients of gold distribution increase with an increase in solution acidity, reaching the maximum in concentrated solutions of hydrochloric acid. The composition of the complex extracted is 1:1. Sulfate- and nitrate-ions do not affect gold-195 extraction in a range of concentrations. The results obtained permit recommending derivatives of 18-crown-6 for concentration of trace amounts of gold from complex solutions