RECOVERY METHOD OF PLATINUM GROUP METAL

摘要

PROBLEM TO BE SOLVED: To provide a method for efficiently recovering platinum group metals from a catalyst-containing wash coat by a simple low-energy and low environmental load treatment.SOLUTION: A method for recovering platinum group metals from a catalyst-containing wash coat includes: a first leaching step of leaching a catalyst-containing wash coat with a first leachate, which is an aqueous solution of an alkali or an inorganic acid, to obtain a leach residue; a second leaching step of leaching the leach residue with a second leachate containing concentrated hydrochloric acid to obtain a leaching pregnant solution; a pH adjustment step of adding a phosphate to the leaching pregnant solution and adjusting its pH to 6-7 using an alkali; and a bio-reduction step of reducing platinum group metal ions contained in the leaching pregnant solution using metal ion-reducing bacteria to precipitate platinum group metals.