Methods for purifying and recycling lead from spent lead-acid batteries

Patent metadata

Field	Value
Publication number	US-2017338530-A1
Application number	US-201715671857-A
Country	US
Kind code	A1
Filing date	Aug 8, 2017
Priority date	Jun 20, 2014
Publication date	Nov 23, 2017
Grant date	—

Abstract

The present disclosure relates to methods by which lead from spent lead-acid batteries may be extracted, purified, and used in the construction of new lead-acid batteries. A method includes: (A) forming a mixture including a carboxylate source and a lead-bearing material; (B) generating a first lead salt precipitate in the mixture as the carboxylate source reacts with the lead-bearing material; (C) increasing the pH of the mixture to dissolve the first lead salt precipitate; (D) isolating a liquid component of the mixture from one or more insoluble components of the mixture; (E) decreasing the pH of the liquid component of the mixture to generate a second lead salt precipitate; and (F) isolating the second lead salt precipitate from the liquid component of the mixture. Thereafter, the isolated lead salt precipitate may be converted to leady oxide for use in the manufacture of new lead-acid batteries.

First claim

1 . A method, comprising:
reacting one or more impurities of a lead salt solution with at least one compound to evolve one or more impurity gases that are released from the lead salt solution, wherein the one or more impurities comprise an element or compound of Group 14, an element or compound of Group 15, an element or compound of Group 16, an element or compound of Group 17, or a combination thereof.

2 . The method of claim 1 , wherein the one or more impurities comprise tellurium, antimony, tin, selenium, arsenic, germanium, silicon, phosphorus, sulfur, or a combination thereof.

3 . The method of claim 1 , wherein the at least one compound comprises sodium tetraborohydride.

4 . The method of claim 1 , wherein the at least one compound comprises sodium hydride.

5 . The method of claim 1 , wherein the at least one compound comprises hydrogen gas.

6 . The method of claim 1 , wherein the at least one compound comprises syngas.

7 . The method of claim 1 , wherein the at least one compound is a reducing agent that reduces at least one impurity dissolved in the solution.

8 . The method of claim 1 , wherein the one or more impurity gases comprise hydrogen telluride, antimony trihydride (stibine), tin tetrahydride (stannane), hydrogen selenide, arsenic trihydride (arsine), germanium tetrahydride (germane), silicon hydrides (silane), phosphine, hydrogen disulfide, or a combination thereof.

9 . The method of claim 1 , comprising acidifying the lead salt solution after the one or more impurity gases have been released to form a lead salt precipitate and then isolating the lead salt precipitate.

10 . The method of claim 9 , comprising treating the lead salt precipitate using calcination or a base treatment to form leady oxide particles.

11 . The method of claim 10 , wherein the leady oxide particles comprise between approximately 0% and approximately 35% free lead.

12 . The method of claim 10 , wherein the leady oxide particles have a D 50 value between approximately 0.2 μm and approximately 20 μm.

13 . The method of claim 10 , wherein the leady oxide particles have a Brunauer-Emmett-Teller (BET) surface area greater than approximately 2.5 square meters per gram (m 2 /g).

14 . The method of claim 10 , wherein the leady oxide particles have an acid absorption greater than approximately 250 milligrams H 2 SO 4 per gram.

15 . The method of claim 10 , wherein the leady oxide comprises less than approximately 20% beta phase lead oxide.

16 . The method of claim 10 , comprising:
forming an active material for use in a lead-acid battery, wherein the active material comprises leady oxide purified from the solution; and constructing a battery comprising the active material.

17 . The method of claim 10 , wherein the lead salt precipitate comprises lead citrate, lead acetate, lead hydroxide, or a combination thereof.

18 . A method, comprising:
(A) forming a mixture comprising a carboxylate source and a lead-bearing material; (B) generating a first lead salt precipitate in the mixture as the carboxylate source reacts with the lead-bearing material; (C) increasing the pH of the mixture to dissolve the first lead salt precipitate; (D) isolating a liquid component of the mixture from one or more insoluble components of the mixture; (E) adding an antisolvent to the liquid component to generate a second lead salt precipitate; and (F) isolating the second lead salt precipitate from the liquid component of the mixture.

19 . The method of claim 18 , wherein the antisolvent comprises: methanol, ethanol, propanol, ethylene glycol, or combinations thereof.

20 . The method of claim 18 , comprising: (G) recovering the antisolvent from the liquid component via distillation.

21 . The method of claim 20 , comprising: (H) recycling the antisolvent into step (E) to generate a second lead salt precipitate.

22 . The method of claim 20 , comprising: (H) recycling the liquid component into step (A) to facilitate leaching of lead solids.

23 . The method of claim 20 , comprising: (H) recycling the liquid component into step (C) to increase the pH of the mixture.

Assignees

• Johnson Controls Tech Co

Inventors

• Spence Matthew A

Classifications

• H01M10/54 Primary

  Reclaiming serviceable parts of waste accumulators · CPC title

• C22B3/04

  by leaching (C22B3/18 takes precedence) · CPC title

• B01J19/06

  Solidifying liquids (making microcapsules B01J13/02) · CPC title

• B01J6/001

  Calcining · CPC title

• C22B13/045

  Recovery from waste materials · CPC title