| 摘要 |
<p>A hydrometallurgical process for recycling the paste and electrolyte of junk lead-acid batteries begins by separating the paste and electrolyte from the junk batteries. The paste and electrolyte are then reacted to increase the lead sulfate content of the paste and reduce the acid content of the electrolyte. Excess liquid is then removed from the mixture of paste and electrolyte, after which the paste is mixed with an aqueous ammoniacal ammonium sulfate solution to dissolve a substantial portion of the lead sulfate from the paste. The remaining solid materials are then separated from the resulting pregnant lead solution, after which lead carbonate is precipitated from the pregnant lead solution by the addition of ammonium carbonate, ammonium bicarbonate or carbon dioxide. The precipitated lead carbonate is removed from the spent liquid and either converted to lead oxide by calcining, or mixed with sulfuric acid and then calcined or reacted with a chemical reducing agent to convert lead dioxide therein to lead oxide, and the lead oxide-containing material is then mixed with sulfuric acid in a second sulfating reaction to increase the lead sulfate content thereof. The resulting product is mixed with an aqueous ammoniacal ammonium sulfate solution to dissolve further lead sulfate therefrom. The resulting pregnant lead solution is separated from any solid materials remaining therein, after which lead carbonate is precipitated from the solution.</p> |
