METHOD OF PREPARING HIGHLY PURE GOLD FROM PURE GOLD CONTAINING SILVER, COPPER IRON, PALLADIUM AND OTHER IMPURITIES Russian patent published in 1998 - IPC

FIELD: hydromethallurgy of noble metals. SUBSTANCE: in order to obtain highly pure (99.99 %) gold, gold is extracted from tributyl phosphate at extracting agent to gold molar ratio of (3.0-4.0): 1.0, and extract is washed with sulfuric acid solution. Subsequent recovery of metal is carried out by well known procedures. Present invention enables one to make process cheaper since extracting agent amounts prove to be significantly less. EFFECT: more efficient preparation method. 1 tbl