Method for producing metallic silver by electro-deposition

Patent metadata

Field	Value
Publication number	US-11384443-B2
Application number	US-201816652991-A
Country	US
Kind code	B2
Filing date	Sep 3, 2018
Priority date	Oct 16, 2017
Publication date	Jul 12, 2022
Grant date	Jul 12, 2022

Abstract

A method for producing metallic silver by electro-deposition, including electrolyzing an electrolyte solution containing Ce(NO3)3 in an anode zone and an electrolyte solution containing AgNO3 in a cathode zone by using an electrolytic cell with a specific diaphragm, wherein the electrolyte solution in the anode zone is not allowed to enter the cathode zone. After the electrolyzing is complete, the metallic silver with a high purity is obtained at the cathode, and a Ce4+-containing solution is obtained in the anode zone.

First claim

What is claimed is:

1. A method for producing metallic silver by electro-deposition, comprising electrolyzing an electrolyte solution containing Ce(NO 3 ) 3 in an anode zone and an electrolyte solution containing AgNO 3 in a cathode zone by using an electrolytic cell with an anion exchange membrane, wherein the electrolyte solution in the cathode zone and the electrolyte solution in the anode zone are not in fluid communication with each other, and after the electrolyzing is complete, the metallic silver is obtained at a cathode of the electrolytic cell, and a solution containing Ce 4+ is obtained in the anode zone, wherein the electrolyte solution in the cathode zone has H + at a concentration of no more than 0.1 mol/L.

2. The method according to claim 1 , wherein the electrolyte solution in the anode zone has H + at a concentration of at least 0.01 mol/L.

3. The method according to claim 1 , wherein the electrolyte solution in the anode zone has H + at a concentration of at least 0.1 mol/L.

4. The method according to claim 1 , wherein the electrolyte solution in the cathode zone has Ag + at a concentration of at least 0.5 mol/L.

5. The method according to claim 1 , wherein the electrolyte solution in the cathode zone has Ag + at a concentration of at least 0.9 mol/L.

6. The method according to claim 1 , wherein the electrolyte solution in the cathode zone has Ce at a concentration of no more than 0.2 mol/L.

7. The method according to claim 1 , wherein the cathode during the electrolyzing has a current density ranging from 100 to 650 A/m 2 .

8. A method for producing metallic silver by electro-deposition, comprising electrolyzing an electrolyte solution containing Ce(NO 3 ) 3 in an anode zone and an electrolyte solution containing AgNO 3 in a cathode zone by using an electrolytic cell with a diaphragm, wherein the diaphragm is one selected from the group consisting of an anion exchange membrane, a membrane with micropores and a membrane with nanopores, wherein only a unidirectional flow of the electrolyte solution in the cathode zone to the anode zone is enabled, and after the electrolyzing is complete, the metallic silver is obtained at a cathode of the electrolytic cell, and a solution containing Ce 4+ is obtained in the anode zone, wherein the unidirectional flow is carried out by means comprising providing at least one of pressure and overflow.

9. The method according to claim 8 , wherein the electrolyte solution in the anode zone contains silver ions.

10. The method according to claim 8 , wherein the electrolyte solution in the anode zone has H + at a concentration of at least 0.01 mol/L.

11. The method according to claim 8 , wherein the electrolyte solution in the cathode zone has Ag + at a concentration of at least 0.5 mol/L.

12. The method according to claim 8 , wherein the cathode during the electrolyzing has a current density ranging from 100 to 650 A/m 2 .

13. A method for producing metallic silver by electro-deposition, comprising electrolyzing an electrolyte solution containing Ce(NO 3 ) 3 in an anode zone and an electrolyte solution containing AgNO 3 in a cathode zone by using an electrolytic cell with an anion exchange membrane, wherein the electrolyte solution in the cathode zone and the electrolyte solution in the anode zone are not in fluid communication with each other, and after the electrolyzing is complete, the metallic silver is obtained at a cathode of the electrolytic cell, and a solution containing Ce 4+ is obtained in the anode zone, wherein the electrolyte solution in the anode zone contains silver ions.

Assignees

• Inst Process Eng Cas

Inventors

• Zhang Hui
• Qi Tao

Classifications

• C25C7/06

  Operating or servicing · CPC title

• C25C7/04

  Diaphragms; Spacing elements · CPC title

• C25C7/02

  Electrodes (consumable anodes for the refining the metals C25C1/00 - C25C5/00); Connections thereof · CPC title

• C25B1/01 Primary

  Products · CPC title

• C25C1/20 Primary

  of noble metals · CPC title