Method for recovering metal from waste printed circuit board and a cell thereof

Patent metadata

Field	Value
Publication number	US-12448695-B2
Application number	US-202217847301-A
Country	US
Kind code	B2
Filing date	Jun 23, 2022
Priority date	Jun 23, 2022
Publication date	Oct 21, 2025
Grant date	Oct 21, 2025

Abstract

A metal recovery device for recovering metal in a waste printed circuit board by way of electrodeposition including: a cathode, an anode, and an electrolyte in electrical communication with the cathode and the anode, wherein the electrolyte includes a glycol-based compound and a metal chloride. A method of preparing an electrolyte for use in the same. A method of metal recovery for recovering metal from waste printed circuit board by making use the same.

First claim

The invention claimed is:

1. A metal recovery device for recovering metal in a waste printed circuit board by way of electrodeposition comprising:
a cathode,
an anode, and
an electrolyte in electrical communication with the cathode and the anode,
wherein the anode, consists of porous reticulated vitreous carbon which exhibits a honeycomb arrangement, is adapted to facilitate the capture of the metal in the waste printed circuit board to undergo oxidative leaching, and the electrolyte comprises a chelating agent of glycol-based compound and potassium chloride to prevent precipitation of the metal ions and maintain the metal ions available for cathodic reductive deposition.

2. The metal recovery device according to claim 1 , wherein the glycol-based compound is a petrochemical.

3. The metal recovery device according to claim 1 , wherein the glycol-based compound is a monomeric glycol.

4. The metal recovery device according to claim 3 , wherein the monomeric glycol is ethylene glycol.

5. The metal recovery device according to claim 3 , wherein the monomeric glycol is propylene glycol.

6. The metal recovery device according to claim 1 , wherein the porous reticulated vitreous carbon has a porosity from about 10 ppi to about 100 ppi.

7. The metal recovery device according to claim 1 , wherein the porous reticulated vitreous carbon is submerged in the electrolyte at a predetermined submerged depth which is determined with reference to the porosity of the anode.

8. The metal recovery device according to claim 1 , wherein the cathode comprises a cathode material selected from a group consisting of nickel, copper, iron, nickel foam, copper foam, aluminum foam, carbon cloth, carbon foam, and a combination thereof.

9. The metal recovery device according to claim 8 , wherein the cathode material is covered by a substantially porous structure.

10. The metal recovery device according to claim 9 , wherein the substantially porous structure has a porosity from about 100 mesh to about 200 mesh.

11. The metal recovery device according to claim 9 , wherein the substantially porous structure comprises a material selected from a group consisting of cotton cloth, porous carbon cloth, plastic cloth and a combination thereof.

12. The metal recovery device according to claim 1 , wherein the electrodeposition is conducted at a current density from about 0.2 mA cm −2 to about 300 mA cm −2 .

13. The metal recovery device according to claim 1 , wherein the metal recovered is a heavy metal.

14. The metal recovery device according to claim 13 , wherein the heavy metal is copper.

15. The metal recovery device according to claim 1 , wherein the electrolyte further comprises NH 4 Cl.

16. The metal recovery device according to claim 1 , wherein the electrolyte is reusable for two or more electrodeposition cycles.

17. The metal recovery device according to claim 16 , wherein sensitivity of the device is between about 50% to about 60% in each electrodeposition cycle.

18. The metal recovery device according to claim 16 , wherein the sensitivity of the device increases with a number of cycles the electrolyte is reused.

19. The metal recovery device according to claim 18 , wherein the device has a sensitivity of about 60% when the electrolyte is reused for three electrodeposition cycles.

20. The metal recovery device according to claim 18 , wherein the number of cycles the electrolyte is reused is proportional to cathodic Faradaic efficiency of the device.

21. The metal recovery device according to claim 20 , wherein the cathodic Faradaic efficiency of the device is at about 99%, when the electrolyte is reused for three electrodeposition cycles.

22. The metal recovery device according to claim 16 , wherein metal selectivity of the device is at least 50% in each electrodeposition cycle.

23. The metal recovery device according to claim 16 , wherein metal recovery of the device is between about 26% to about 70% in each electrodeposition cycle.

Assignees

• Univ City Hong Kong

Inventors

• Lam Chun Ho

Classifications

• C25C1/20

  of noble metals · CPC title

• C25C1/16

  of zinc, cadmium or mercury · CPC title

• C25C1/12

  of copper · CPC title

• C22B7/006

  Wet processes · CPC title

• Y02P10/20

  Recycling · CPC title