Systems and methods for closed-loop recycling of a liquid component of a leaching mixture when recycling lead from spent lead-acid batteries

Patent metadata

Field	Value
Publication number	US-9555386-B2
Application number	US-201414498798-A
Country	US
Kind code	B2
Filing date	Sep 26, 2014
Priority date	Jun 20, 2014
Publication date	Jan 31, 2017
Grant date	Jan 31, 2017

Abstract

The present disclosure relates generally to systems and methods for recycling lead-acid batteries, and more specifically, relates to purifying and recycling the lead content from lead-acid batteries. A system includes a reactor that receives and mixes a lead-bearing material waste, a carboxylate source, and a recycled liquid component to form a leaching mixture yielding a lead salt precipitate. The system also includes a phase separation device coupled to the reactor, wherein the phase separation device isolates the lead salt precipitate from a liquid component of the leaching mixture. The system further includes a closed-loop liquid recycling system coupled to the phase separation device and to the reactor, wherein the closed-loop liquid recycling system receives the liquid component isolated by the phase separation device and recycles a substantial portion of the received liquid component back to the reactor as the recycled liquid component.

First claim

The invention claimed is:

1. A method, comprising:
forming a leaching mixture comprising a lead-bearing material, a carboxylate source, and a recycled liquid component, wherein the leaching mixture generates a lead carboxylate precipitate as the carboxylate source reacts with the lead-bearing material in the leaching mixture, wherein the carboxylate source comprises citric acid, a salt of citric acid, or a combination thereof;
isolating a liquid component from the lead carboxylate precipitate of the leaching mixture;
purifying at least a portion of the isolated liquid component, wherein purifying comprises removing at least a portion of one or more sulfates from the portion of the isolated liquid component; and
recycling the portion of the isolated liquid component back into the leaching mixture as the recycled liquid component after purification.

2. The method of claim 1 , wherein purifying comprises removing at least one dissolved metal other than lead from the portion of the isolated liquid component.

3. The method of claim 1 , wherein purifying comprises mixing calcium hydroxide with the portion of the isolated liquid component and subsequently removing calcium sulfate precipitate before recycling.

4. The method of claim 1 , wherein purifying comprises using an ion exchange resin to remove one or more sulfates from the portion of the isolated liquid component.

5. The method of claim 1 , wherein purifying comprises removing one or more impurities from the portion of the isolated liquid component without substantially removing dissolved lead carboxylate.

6. The method of claim 1 , wherein isolating the liquid component from the lead carboxylate precipitate comprises using a belt dryer, a filter press, a clarifier, or a cyclone separator to isolate the liquid component.

7. The method of claim 1 , comprising treating the lead carboxylate precipitate to yield leady oxide after isolating the liquid component from the lead carboxylate precipitate.

8. The method of claim 7 , wherein treating comprises oxidizing the lead carboxylate precipitate into leady oxide using a belt dryer, a spray calciner, a stirred pot reactor, a rotary kiln calciner, or a combination thereof.

9. The method of claim 7 , wherein treating comprises reacting the lead carboxylate precipitate with a hydroxide to yield the leady oxide.

10. The method of claim 1 , wherein the carboxylate source comprises acetic acid, a salt of acetic acid, or a combination thereof.

11. The method of claim 1 , wherein the leaching mixture comprises a peroxide.

12. The method of claim 1 , wherein purifying comprises using a nanofilter to remove one or more sulfates from the portion of the isolated liquid component.

13. The method of claim 2 , wherein the at least one metal comprises sodium, barium, calcium, antimony, arsenic, tin, or combinations thereof.

Assignees

• Johnson Controls Tech Co

Inventors

• Meissner Eberhard
• Bauer Jürgen
• Spence Matthew A

Classifications

• B01J6/002

  using rotating drums · CPC title

• H01M10/54 Primary

  Reclaiming serviceable parts of waste accumulators · CPC title

• B01J19/2465

  externally, i.e. the mixture leaving the vessel and subsequently re-entering it · CPC title

• H01M6/52

  Reclaiming serviceable parts of waste cells or batteries {, e.g. recycling} · CPC title

• C22B7/006

  Wet processes · CPC title