Zinc recovery method

Patent metadata

Field	Value
Publication number	US-2024044029-A1
Application number	US-202018266711-A
Country	US
Kind code	A1
Filing date	Dec 14, 2020
Priority date	Dec 14, 2020
Publication date	Feb 8, 2024
Grant date	—

Abstract

The present zinc recovery method is characterized in including a dissolving process of treating a raw material containing zinc with an alkaline fluid at a temperature equal to or higher than 100° C. to dissolve zinc contained in the raw material, and a recovering process of recovering zinc extracted from the raw material by the dissolving process.

First claim

1 . A zinc recovery method, comprising:
a dissolving step of treating a raw material containing zinc with an alkaline fluid at a temperature equal or higher than 100° C. to dissolve zinc contained in the raw material; and a recovering step of recovering zinc extracted from the raw material by the dissolving step, wherein the recovering step includes an electrolyzing step of obtaining metallic zinc from a liquid phase containing zinc by electrolysis, an alkali washing step of washing the raw material with an alkali aqueous solution to remove soluble halogen compounds prior to the dissolving step is further included, a concentration of the alkali aqueous solution to be used in the alkali washing step is set to be lower than a concentration of the alkaline fluid to be used in the dissolving step, and the alkali aqueous solution having been used for washing in the alkali washing step contains the soluble halide and is discharged outside a system without being sent to the dissolving step and the electrolyzing step while the raw material from which the soluble halogen compounds have been removed with the alkali aqueous solution by the alkali washing step is sent to the dissolving step, the alkaline fluid in which the zinc contained in the raw material has been dissolved is obtained in the dissolving step, and a chlorine concentration in the liquid phase derived from the alkaline fluid to be used as an electrolytic bath is equal to or lower than 1000 ppm in the electrolyzing step.

2 . The zinc recovery method according to claim 1 , wherein the raw material contains iron.

3 . The zinc recovery method according to claim 1 , wherein the raw material contains zinc ferrite.

4 . The zinc recovery method according to claim 1 , wherein the dissolving step is performed in atmospheric pressure and at a temperature between 100° C. and 200° C.

5 . The zinc recovery method according to claim 1 , wherein the dissolving step is performed under a pressurized condition in pressure higher than atmospheric pressure by 0.017 MPa to 2 MPa and at a temperature between 105° C. and 220° C.

6 . (canceled)

7 . The zinc recovery method according to claim 1 , wherein
the raw material contains an organic halogen compound, the recovering step includes an electrolyzing step of obtaining metallic zinc from a liquid phase containing zinc by electrolysis, and the organic halogen compound is decomposed with the alkaline fluid in the dissolving step to discharge halogen outside a system prior to the electrolyzing step.

8 . The zinc recovery method according to claim 1 , wherein the recovering step includes a solid-liquid separating step of separating a solid phase containing iron contained in the raw material, and a liquid phase containing zinc from each other.

9 . The zinc recovery method according to claim 1 , wherein zinc is recovered as a zinc metal in the recovering step.

10 . (canceled)

11 . The zinc recovery method according to claim 1 , wherein
a reproducing step of reproducing an alkaline fluid from alkali metal salt contained in residues having been subjected to the recovering step by electrolysis or concentration is included, and the alkaline fluid obtained in the reproducing step is supplied to the dissolving step.

Assignees

• Jgc Corp
• Kinotech Corp

Inventors

• Sauda Kenzo
• Iosaki Masaaki

Classifications

• C25C1/16 Primary

  of zinc, cadmium or mercury · CPC title

• C22B19/20 Primary

  Obtaining zinc otherwise than by distilling · CPC title

• Y02P10/20

  Recycling · CPC title

• C22B19/30

  from metallic residues or scraps · CPC title