METHOD OF EXTRACTING GOLD FROM HYDROCHLORIC ACID SOLUTION Russian patent published in 2015 - IPC C22B11/00 C22B3/26 

FIELD: chemistry.

SUBSTANCE: invention relates to hydrometallurgy of noble metals and can be used in extraction of gold (III) from hydrochloric acid solutions from leaching gold-containing intermediate products and concentrates. Extraction is carried out from a hydrochloric acid solution with concentration of 1-5 mol/l HCl. The extractant added to the solution is an undiluted secondary C₇-C₁₂ aliphatic alcohol with a normal structure. Extraction is carried out with a countercurrent at 2-4 steps with organic to aqueous ratio of 1:2-20 with transfer of gold (III) into the extract, and the main part of the acid and impurity elements into the raffinate. The process is carried out while ensuring equilibrium concentration of hydrochloric acid in the raffinate of 1-5 mol/l until achieving residual content of gold in the raffinate of less than 3 mg/l. The saturated extract is washed with water or hydrochloric acid solution with concentration of 0.1-0.5 mol/l at 1-4 steps with organic to aqueous ratio of 3-20:1. After washing the extract, gold (III) is re-extracted with ammonia solution or thiourea solution while recycling the purified extractant to the extraction step.

EFFECT: achieving extraction of gold of up to 99,40-99,99%, reduced combined extraction of impurities and reduced material flow.

6 cl, 8 ex