Methods for recovering metals from electronic waste, and related systems

Patent metadata

Field	Value
Publication number	US-9777346-B2
Application number	US-201514845101-A
Country	US
Kind code	B2
Filing date	Sep 3, 2015
Priority date	Sep 3, 2015
Publication date	Oct 3, 2017
Grant date	Oct 3, 2017

Abstract

A method of recovering metals from electronic waste comprises providing a powder comprising electronic waste in at least a first reactor and a second reactor and providing an electrolyte comprising at least ferric ions in an electrochemical cell in fluid communication with the first reactor and the second reactor. The method further includes contacting the powders within the first reactor and the second reactor with the electrolyte to dissolve at least one base metal from each reactor into the electrolyte and reduce at least some of the ferric ions to ferrous ions. The ferrous ions are oxidized at an anode of the electrochemical cell to regenerate the ferric ions. The powder within the second reactor comprises a higher weight percent of the at least one base metal than the powder in the first reactor. Additional methods of recovering metals from electronic waste are also described, as well as an apparatus of recovering metals from electronic waste.

First claim

What is claimed is:

1. A method of sequentially recovering metals from electronic waste, the method comprising:
providing a powder comprising electronic waste in at least a first reactor and a second reactor;
providing an electrolyte comprising at least ferric ions in an electrochemical cell in fluid communication with the first reactor and the second reactor;
contacting the powder within the first reactor with the electrolyte to dissolve at least one base metal from the powder into the electrolyte and reduce at least some of the ferric ions to ferrous ions while a plurality of precious metals remain in the powder;
contacting the powder within the second reactor with the electrolyte to dissolve at least one base metal from the powder into the electrolyte according to the same reactions in which the powder in the first reactor is dissolved into the electrolyte, the powder in the second reactor comprising a higher weight percent of the at least one base metal than the powder in the first reactor while a plurality of precious metals remain in the powder;
oxidizing the ferrous ions at an anode of the electrochemical cell to regenerate the ferric ions;
after contacting the powder within the first reactor with the electrolyte, placing the first reactor out of fluid communication with the first electrochemical cell and in fluid communication with a leaching vessel comprising a thiosulfate and, while the powder remains within the first reactor, contacting the powder with the thiosulfate to selectively dissolve silver from the powder; and
after contacting the powder within the first reactor with the thiosulfate and dissolving the silver therefrom, placing the first reactor out of fluid communication with the leaching vessel and in fluid communication with another electrochemical cell comprising an iodide electrolyte formulated to dissolve gold from the powder within the first reactor while other precious metals remain in the powder.

2. The method of claim 1 , further comprising reducing the at least one dissolved base metal from each of the first reactor and the second reactor at a cathode of the electrochemical cell.

3. The method of claim 1 , further comprising selecting the iodide electrolyte to have a molarity between about 0.05 M and about 1.0 M.

4. The method of claim 1 , further comprising contacting the powder within the first reactor with the iodide electrolyte to dissolve gold from the powder within the first reactor in the iodide electrolyte and depositing the dissolved gold on a cathode of the another electrochemical cell.

5. The method of claim 1 , further comprising reducing a plurality of base metals at the cathode of the electrochemical cell to form an alloy of the plurality of base metals.

6. The method of claim 1 , further comprising:
after contacting the powder within the second reactor with the electrolyte, providing a third reactor including a powder having a higher weight percent of the at least one base metal than the powder within the second reactor; and
flowing the electrolyte from the electrochemical cell to the second reactor, from the second reactor to the third reactor, and from the third reactor to the electrochemical cell.

7. The method of claim 1 , further comprising selecting the electrolyte to comprise hydrochloric acid, wherein contacting the powder within the first reactor with the electrolyte comprises forming silver chloride.

8. The method of claim 1 , further comprising adding zinc powder to the thiosulfate to precipitate the silver.

9. The method of claim 1 , further comprising, after dissolving the gold from the powder within the first reactor, contacting the powder within the first reactor with a leachate comprising hydrogen peroxide and hydrochloric acid to dissolve palladium from the powder.

10. The method of claim 1 , further comprising shredding the electronic waste and separating magnetic materials from non-magnetic materials thereof.

11. The method of claim 10 , further comprising contacting the magnetic materials with a leachate comprising sulfuric acid and forming a double salt of rare earth elements of the magnetic materials.

12. A reactor system for recovering metals from electronic waste, the reactor system comprising:
a plurality of reactors substantially filled with a powder comprising electronic waste;
a first electrochemical cell comprising a first electrolyte including ferrous ions, ferric ions, and one of hydrochloric acid or sulfuric acid;
a first leaching vessel including a first leachate formulated to dissolve silver;
a second electrochemical cell comprising an electrolyte comprising iodide; and
a second leaching vessel including a second leachate, the second leachate formulated to leach palladium from the powder in the plurality of reactors,
wherein each reactor of the plurality of the reactors is configured to be placed in fluid communication with each of the first electrochemical cell, the first leaching vessel, the second electrochemical cell, and the second leaching vessel while the powder remains within the respective reactor of the plurality of reactors.

13. The reactor system of claim 12 , wherein the first leachate comprises thiosulfate.

14. The reactor system of claim 12 , wherein the second leachate comprises hydrogen peroxide and hydrochloric acid.

15. The reactor system of claim 12 , wherein the plurality of reactors is configured such that the first electrolyte flows from the first electrochemical cell to a first reactor of the plurality of reactors, from the first reactor of the plurality of reactors to a second reactor of the plurality of reactors, and from the second reactor of the plurality of reactors to the first electrochemical cell.

16. The reactor system of claim 15 , wherein the second reactor comprises powder having a higher weight percent of at least one of lead, tin, zinc, nickel, and copper than powder in the first reactor.

17. The reactor system of claim 15 , wherein the second electrochemical cell is in fluid communication with a third reactor while the first electrochemical cell is in fluid communication with the first reactor and the second reactor.

18. A method of recovering metals from electronic waste, the method comprising:
providing a first reactor including powderized electronic waste, a second reactor including powderized electronic waste, and a third reactor including powderized electronic waste;
providing a first electrolyte comprising iron ions in a first electrochemical cell;
passing the first electrolyte from the first electrochemical cell to the first reactor, from the first reactor to the second reactor, and from the second reactor to the first electrochemical cell to dissolve at least one of copper, nickel, lead, tin, and zinc from the powderized electronic waste in each of the first reactor and the second reactor to form silver chloride in the first reactor;
reducing at least one of dissolved copper, dissolved nickel, dissolved lead, dissolved tin, and dissolved zinc from within the first electrolyte at a cathode of the first electrochemical cell;
providing a first vessel comprising a thiosulfate;
placing the first reactor out of fluid communication with the first electrochemical cell and in fluid communication with the first vessel;
placing the third reactor in fluid communication with the first electrochemical cell;
after dissolving at least one of copper, nickel, lead, tin, and zinc from the powderized electronic waste in the first reactor and placing the first reactor out of fluid communication with the first electrochemical cell and in

Assignees

• Battelle Energy Alliance Llc
• Battelle Energy Alliance Llc

Inventors

• Lister Tedd E
• Parkman Jacob A
• Diaz Aldana Luis A
• Clark Gemma
• Dufek Eric J
• Keller Philip

Classifications

• C25C7/02

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

• C25C1/20

  of noble metals · CPC title

• C25C1/16

  of zinc, cadmium or mercury · CPC title

• C25C1/08

  of nickel or cobalt · CPC title

• C22B3/10

  Hydrochloric acid {, other halogenated acids or salts thereof} · CPC title