Devices and method for smelterless recycling of lead acid batteries
AssigneeAqua Metals Inc.
InventorsBrian Dougherty, Michael John King, Robert Lewis Clarke, Stephen R. Clarke, Michael David Hurwitz
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Abstract
Lead from lead acid battery scrap is recovered in two separate production streams as clean grid lead and as high-purity lead without smelting. In preferred aspects, lead recovery is performed in a continuous process that uses an aqueous electroprocessing solvent and electro-refining. Spent electroprocessing solvent and/or base utilized to treat lead paste from the lead acid battery scrap can be recycled to the recovery process.
Claims19
A method of continuously and electrochemically producing high-purity lead from a lead ion-enriched electroprocessing solvent, comprising:
- treating active lead materials with a base to generate base-treated active lead material that includes lead oxides and lead hydroxides;
- dissolving the base-treated active lead material lead in an electroprocessing solvent to so form a lead ion-enriched electroprocessing solvent, wherein the electroprocessing solvent comprises an alkane sulfonic acid and does not include a chelator;
- reducing lead ions in the lead ion-enriched electroprocessing solvent on a cathode to form adherent, high-purity lead and a regenerated electroprocessing solvent wherein high-purity lead is loosely attached to the cathode and produced as a micro- or nanoporous mixed matrix enclosing molecular hydrogen (H2) and the electroprocessing solvent and wherein the high-purity lead has a purity of at least 99.5%, wherein the cathode comprises aluminum;
- removing the adherent high-purity lead from one portion of the cathode while lead ions are reduced on another portion of the cathode, wherein the cathode is moved relative to the lead ion-enriched electroprocessing solvent during the step of reducing the lead ions;
- contacting at least some of the regenerated electroprocessing solvent with additional active lead materials to so produce at least a portion of the lead ion-enriched electroprocessing solvent.
A method for recycling a lead acid battery, comprising:
- obtaining a first quantity of lead paste from the lead acid battery, the lead paste comprising lead sulfate;
- contacting the first quantity of lead paste with a base, thereby generating a supernatant and a first precipitate, wherein the first precipitate comprises lead hydroxide;
- processing the supernatant to thereby generate a second product stream comprising a regenerated base;
- contacting the first precipitate with an electroprocessing solvent to generate a lead ion containing solution, wherein the solvent comprises an alkane sulfonic acid and does not include a chelator;
- contacting the lead ion containing solution with a collection cathode, wherein the collection cathode comprises aluminum;
- applying an electrical potential to the collection cathode, thereby depositing adherent metallic lead loosely attached to the collection cathode and producing a third product stream comprising a regenerated electroprocessing solvent;
- wherein the adherent metallic lead is produced as a micro- or nanoporous mixed matrix enclosing molecular hydrogen (H2) and the electroprocessing solvent, and wherein the lead has a purity of at least 99.5%;
- collecting the adherent metallic lead from the collection cathode, wherein the cathode is moved relative to the electroprocessing solvent;
- contacting a second quantity of lead paste with at least a portion of the second product stream to generate a second precipitate;
- and
- contacting the second precipitate with at least a portion of the third product stream.
Dependencies are inferred from the claim text.