IP Library › Granted Patent US 12,723,291
Granted Patent B2
US 12,723,291 · App. 18/685,982 · Granted Sep 1, 2026

Method for recovering metal from metal element-containing substance

Inventor: Yasuyuki Fukushima (Tokyo, JP)
Assignee: IHI CORPORATION
C22B3/18C22B11/04
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Quick Facts
Patent No.
US 12,723,291
App. No.
18/685,982
Granted
Sep 1, 2026
Kind
B2
Abstract

A method for recovering a metal from a metal element-containing substance includes: bringing a metal element-containing substance into contact with a dissolving solution containing nitric acid and a salt to obtain a solution containing a metal ion or metal complex ion; and immersing an alga in the solution containing a metal ion or metal complex ion to produce a metal, wherein the concentration of nitric acid in the dissolving solution containing nitric acid and a salt is 2 to 50 mass %, and wherein the concentration of the salt in the dissolving solution containing nitric acid and a salt is 0.5 mass % or more.

Claims (19)

1 . A method for recovering a metal from a metal element-containing substance, comprising steps of:

bringing the metal element-containing substance into contact with a dissolving solution comprising nitric acid and a salt to obtain a solution comprising a metal ion or metal complex ion; and

immersing an alga in the solution comprising a metal ion or metal complex ion to produce a metal,

wherein a concentration of nitric acid in the dissolving solution is 2 to 50 mass %, and

wherein a concentration of the salt in the dissolving solution is 0.5 mass % or more.

2 . The method according to claim 1 , wherein the alga is a blue-green alga of a genus Leptolyngbya.

3 . The method according to claim 2 , wherein the blue-green alga of the genus Leptolyngbya is a blue-green alga of the genus Leptolyngbya deposited with accession number FERM BP-22385.

4 . The method according to claim 1 , wherein the concentration of nitric acid in the dissolving solution is 3 to 20 mass %.

5 . The method according to claim 1 , wherein a concentration of hydrochloric acid in the dissolving solution is 20 mass % or less.

6 . The method according to claim 1 ,

wherein the metal element-containing substance comprises at least one selected from the group consisting of gold, palladium, platinum, and rhodium,

wherein the solution comprising a metal ion or metal complex ion is a solution comprising an ion or complex ion of at least one metal selected from the group consisting of gold, palladium, platinum, and rhodium, and

wherein the metal to be recovered is at least one selected from the group consisting of gold, palladium, platinum, and rhodium.

7 . The method according to claim 2 , wherein the concentration of nitric acid in the dissolving solution is 3 to 20 mass %.

8 . The method according to claim 2 , wherein a concentration of hydrochloric acid in the dissolving solution is 20 mass % or less.

9 . The method according to claim 2 ,

wherein the metal element-containing substance comprises at least one selected from the group consisting of gold, palladium, platinum, and rhodium,

wherein the solution comprising a metal ion or metal complex ion is a solution comprising an ion or complex ion of at least one metal selected from the group consisting of gold, palladium, platinum, and rhodium, and

wherein the metal to be recovered is at least one selected from the group consisting of gold, palladium, platinum, and rhodium.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Feb 23, 2024
From: FUKUSHIMA, YASUYUKI
To: IHI CORPORATION
Reel/Frame 066540/0020 →
Priority Claims (1)
JP 2021-141688 · Aug 31, 2021 · national
Continuity (1)
Related Publication 20250179608A1 · Jun 5, 2025
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