Abstract
Extraction of HAuCl4 with diethylene glycol dibutyl ether (dibutyl carbitol) was studied in the gold(III) concentration range 10−6−1.5 mol/L at cHCl = 1 mol/L and T = 25°C, distribution ratios were determined. Experiments were made at other cHCl. A unified extraction isotherm was obtained with the use of activity coefficients of HAuCl4. The main extraction equilibrium is Haq+ + AuCl4aq− = HAuCl4 org, K0 (extractant and water molecules are omitted). For low cAulogK0 = 1.89 ± 0.06. Dimerization equilibrium 2HAuCl4 org = (HAuCl4)2 org has logK2 = 2.1. Extracts are electrically conducting, the share of ionic subsystem increases with CAu and reaches about 10% at cAu org = 0.1 mol/L. Alteration of phase volumes on extraction was studied: ΔVaq ≈ −0.20nAu, ΔVorg = −0.8ΔVaq, where nAu is the number of moles of gold(III) that transfer from aqueous into organic phase. It was shown that 6 ± 1 water molecules are co-extracted with each HAuCl4 molecule.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call