METHOD OF PREPARING RHODIUM, PALLADIUM, AND RUTHENIUM CONCENTRATES FROM NITRIC ACID SOLUTIONS

FIELD : precious metal technology. SUBSTANCE : objective of invention is, in particular, method of preparing concentrates of rare platinum metals and palladium, which method can be used for recovering platinum metals from slimes produced by electrolytic refining of copper and nickel, processing nuclear fuel, processing exhausted catalysts and scrap of electrical and electronic machinery. Precipitation is effected from solutions with 2-3 mole/l nitric acid concentration by adding thereto alkali metal thiocyanate in solid state in excess constituting 1/3 part of nitric acid in solution and at temperature 18 to 80оС. Subsequent calcination of precipitate is performed at 750-800оС. EFFECT : improved environmental safety, simplified process at the same degree of precious metal recovery. 2 cl, 1 tbl, 2 ex