	US 12,442,058 B2
	Method for recovering precious metal from precious metal-containing waste catalyst
Bin Zhang, Nanjing (CN); and Chen Chen, Nanjing (CN)
Assigned to HERAEUS PRECIOUS METAL TECHNOLOGY (CHINA) CO., LTD., Nanjing (CN)
Appl. No. 17/996,467
Filed by Heraeus Precious Metal Technology (China) Co., Ltd., Nanjing (CN)
PCT Filed Jan. 21, 2021, PCT No. PCT/CN2021/073038 § 371(c)(1), (2) Date Oct. 18, 2022, PCT Pub. No. WO2021/212936, PCT Pub. Date Oct. 28, 2021.
Claims priority of application No. 202010327422.5 (CN), filed on Apr. 23, 2020.
Prior Publication US 2023/0212712 A1, Jul. 6, 2023
Int. Cl. C22B 11/00 (2006.01); C22B 7/00 (2006.01)

CPC C22B 11/048 (2013.01) [C22B 7/008 (2013.01); C22B 7/009 (2013.01)]

20 Claims

1. A method for recovering a precious metal from a precious metal-containing waste catalyst, the method comprising the following steps:

i) at least partially dissolving a precious metal-containing waste catalyst in an alkaline aqueous solution, where the precious metal-containing waste catalyst is a supported catalyst comprising an SiO₂carrier and a precious metal, where the precious metal is one or more of platinum, palladium, rhodium, iridium, osmium, ruthenium, gold, and silver;

ii) performing filtering to obtain a precious metal-containing filtrate and the precious metal;

iii) treating the filtrate with a reducing agent; and

iv) separating the precious metal from the filtrate after treatment,

wherein step iii) is performed under a pressure of 8-12 bar at a temperature of 190-210° C. for 2-4 h.