Systems and methods for aqueous recovery of lead from lead acid batteries with reduced electrolyte demand

A method of reducing lead dioxide build-up in an electrochemical lead recovery operation that recovers metallic lead from lead paste of a lead acid battery, and that uses and recycles an electrolyte in which lead dioxide is insoluble, comprising:

• providing the lead paste, wherein the lead paste comprises lead dioxide and no more than 2.0 wt % of sulfate;
• heating the lead paste to reduce at least 50% of the lead dioxide to lead oxide, thereby forming a decomposed lead paste;
• combining the decomposed lead paste with a recycled electrolyte to form a lead ion enriched electrolyte;
• and
• subjecting the lead ion enriched electrolyte to an electrochemical lead recovery operation to thereby recover metallic lead on a cathode and generate the recycled electrolyte.

A method of preserving an effective concentration of an electrolyte and reducing lead dioxide build-up in the electrolyte in a continuous electrochemical lead recovery operation that recovers metallic lead from desulfurized lead paste of a lead acid battery, comprising:

• providing the desulfurized lead paste, wherein the desulfurized lead paste comprises lead dioxide, lead hydroxide, and/or lead carbonate, and further comprises residual sulfate;
• washing the desulfurized lead paste thereby forming a washed desulfurized lead paste comprising residual water present in the desulfurized lead paste of between about 10 wt % to 30 wt %;
• heating the washed desulfurized lead paste to reduce the residual water to equal or less than 10 wt % and to reduce at least 50% of the lead dioxide to lead oxide, thereby forming a dried decomposed desulfurized lead paste;
• combining the dried decomposed desulfurized lead paste with the electrolyte to form a lead ion enriched electrolyte;
• and
• subjecting the lead ion enriched electrolyte to the electrochemical lead recovery operation to thereby recover metallic lead on a cathode and generate a recycled electrolyte.