Method of recovering iridium

Patent metadata

Field	Value
Publication number	US-12467117-B2
Application number	US-202017755113-A
Country	US
Kind code	B2
Filing date	Oct 21, 2020
Priority date	Oct 28, 2019
Publication date	Nov 11, 2025
Grant date	Nov 11, 2025

Abstract

The present invention relates to a method of recovering iridium in the form of iridium solutions, metal, oxides or salts from a body, such as a spent catalyst, comprising iridium oxides.

First claim

The invention claimed is:

1 . A method of recovering iridium from a body comprising Ir x O y nanoparticles, wherein x is a number between 1 and 2 and y is a number between 1 and 4, wherein said body is a spent catalyst for water electrolysis, wherein said method comprises:
contacting said body with a reducing agent, wherein said reducing agent is an aqueous solution of hydrazine having a mean weight percent concentration wt % higher than 35%, thereby forming a suspension; and dissolving said suspension by exposing said suspension to an acidic solution, wherein said acid solution comprises hydrogen halides having a concentration between 0.5 M to 1 M and one or more halide salts, thereby forming a solution comprising iridium ions.

2 . The method of recovering iridium according to claim 1 , wherein said Ir x O y comprises Ir(IV) oxides compounds.

3 . The method of recovering iridium according to claim 1 , wherein said suspension is a suspension of Ir x O y compounds comprising Ir(III) oxides particles.

4 . The method of recovering iridium according to claim 1 , wherein said contacting said body with a reducing agent comprises contacting said body with a reducing agent for a period of time between 5 and 30 minutes at room temperature.

5 . The method of recovering iridium according to claim 1 , wherein said contacting said body with a reducing agent comprises contacting said body with a reducing agent under sonication.

6 . The method of recovering iridium according to claim 1 , wherein said dissolving comprises dissolving said suspension by exposing said suspension to a solution comprising hydrogen halides for a period of time between 10 minutes to 4 hours at a temperature between 50° C. and 120° C. at the pressure of 1 Atm.

7 . The method according to claim 1 , further comprising:
precipitating said iridium ions as Ir metal particles by exposing said solution containing iridium ions to a reducing agent at a temperature between 60° C. and 100° C. for a period of time between 1 hour and 3 hours.

8 . The method according to claim 1 , further comprising:
precipitating said iridium ions as Ir x O y , by contacting said solution containing iridium ions with NaOH at a temperature between 100° C. and 200° C. for a period of time between 10 minutes and 60 minutes at a pressure between 1 and 10 Atm.

9 . The method according to claim 1 , further comprising:
precipitating said iridium ions as Ir salts by contacting said solution containing iridium ions with H 2 O 2 , and by adding NH 4 Cl in a concentration 3M eq. to said oxidized solution containing iridium ions.

10 . The method of claim 1 , wherein the acid solution comprises HCl.

Assignees

• Univ Syddansk

Inventors

• Andersen Shuang Ma
• Sharma Raghunandan

Classifications

• C22B3/44

  by chemical processes (treatment or purification of solutions by liquid-liquid extraction C22B3/26, by ion-exchange extraction C22B3/42) · CPC title

• Y02P10/20

  Recycling · CPC title

• C22B11/048 Primary

  from spent catalysts · CPC title

• C22B11/04 Primary

  by wet processes (extraction of metal compounds by leaching in organic solutions C22B3/16; treatment or purification of solutions by liquid-liquid extraction C22B3/26) · CPC title