Solvent Extraction of Gold(I) Directly from Alkaline Cyanide Solution with Dibutyl Sulfoxide and n-Octanol

摘要

The direct extraction of gold from alkaline cyanide solution with dibutyl sulfoxide and n-octanol diluted in kerosene was investigated. It has been indicated that the gold extraction percentage increases by increasing dibutyl sulfoxide concentration, n-octanol concentration, and organic-to-aqueous (O/A) phase ratio, but decreases with the increase of initial gold concentration and equilibrium pH of the aqueous phase. No gold extraction was observed using n-octanol alone as an extractant, but n-octanol had an obvious synergistic effect on gold extraction with dibutyl sulfoxide. The extraction reaction was rapid for the extraction equilibrium and could be established within 3 minutes. Gold loaded in the organic phase could be stripped effectively by Na2S2O3 solution. It was indicated that at Na2S2O3 concentration 0.12 mol·L?3, aqueous-to-organic (A/O) phase ratio 1.0, and retention time of 5 minutes, the gold stripping percentage reached 92.6 pct.