US 11,866,802 B2
Method for recovering platinum group metals
Minoru Kawasaki, Tokyo (JP); Hiromitsu Yatsuhashi, Tokyo (JP); and Nobuaki Kita, Tokyo (JP)
Assigned to DOWA METALS & MINING CO., LTD., Tokyo (JP)
Filed by DOWA METALS & MINING CO., LTD., Tokyo (JP)
Filed on Dec. 22, 2021, as Appl. No. 17/558,717.
Claims priority of application No. 2021-124293 (JP), filed on Jul. 29, 2021.
Prior Publication US 2023/0045764 A1, Feb. 9, 2023
Int. Cl. C22B 11/02 (2006.01); C22B 1/00 (2006.01); C22B 7/00 (2006.01)
CPC C22B 11/02 (2013.01) [C22B 1/005 (2013.01); C22B 7/003 (2013.01); C22B 11/026 (2013.01)] 6 Claims
 
1. A method for recovering platinum group metals, comprising:
melting a material to be treated containing platinum group metals, under heating in a furnace, along with a copper source material containing at least one of a metallic copper and a copper oxide, a flux component, and a reducing agent;
separating a molten metal absorbing the platinum group metals, and a slag oxide, through difference in specific gravity;
then subjecting the molten metal absorbing the platinum group metals to an oxidation treatment to form an oxide layer and a molten metal containing metallic copper as a major component containing the platinum group metals concentrated therein; and
separating the oxide layer containing copper oxide as a major component, and the molten metal containing metallic copper as a major component containing the platinum group metals concentrated therein, through difference in specific gravity,
a silver content in the molten metal separated in melting under heating being controlled to 2,000 ppm or more and 8,000 ppm or less.