METHOD FOR PURIFICATION OF RHODIUM SOLUTION FROM IMPURITIES Russian patent published in 2023 - IPC C22B11/00 C25C1/20 C01G55/00 

FIELD: hydrometallurgy of precious metals.

SUBSTANCE: refining of platinum group metals (PGM) used to remove platinum group metal impurities from a rhodium solution. The method includes evaporating the initial rhodium solution, oxidizing the solution, adding ammonium chloride to the solution, separating the precipitate by filtration, extracting platinum group metal impurities from the filtrate with tributyl phosphate, and re-extracting them with a hydrochloric acid solution. After evaporation of the initial solution, electrolytic reduction of rhodium and impurities of platinum group metals is carried out, the resulting cathode precipitate is separated from the solution, dissolved by hydrochlorination in hydrochloric acid and heated.

EFFECT: achievement of complete purification of a rhodium solution from impurities of platinum metals, as well as concentration and separation of the main part of platinum, palladium, iridium and ruthenium into a precipitate of chloroammonium salts, which is sent to the refining of platinum group metals.

5 cl, 4 tbl, 4 ex