Spent lead paste(SLP)presents a major recycling challenge in lead-acid battery treatment due to its insoluble lead compounds.This study develops an innovative and environmentally sustainable approach by integrating(NH...Spent lead paste(SLP)presents a major recycling challenge in lead-acid battery treatment due to its insoluble lead compounds.This study develops an innovative and environmentally sustainable approach by integrating(NH_(4))_(2)SO_(4)-NH_(3)·H_(2)O with suspension electrolysis,effectively converting poorly soluble PbSO_(4)into soluble[Pb(NH_(3))_(4)]^(2+)complexes.The electrolytic conversion mechanisms of SLP components are systematically elucidated,revealing four distinct transformation pathways:1)metallic Pb undergoes complete dissolution as[Pb(NH_(3))_(4)]^(2+)complexes followed by cathodic reduction to elemental lead;2)PbO_(2)increases after suspension electrolysis since part of PbO is oxidized;3)PbO demonstrates dual behavior,with 45.74%undergoing anodic oxidation to PbO_(2) while the remainder(54.26%)participates in cathodic electrodeposition;4)PbSO_(4)exhibits triple conversion routes,including:1)32.98%transformation through intermediate(NH_(4))Pb(OH)SO_(4)formation followed by anodic conversion to PbO·PbSO_(4),2)21.36%direct cathodic reduction to metallic lead,and 3)the residual fraction maintaining soluble[Pb(NH_(3))_(4)]^(2+)speciation in the electrolyte.The optimized process achieves exceptional current efficiency(95.49%)and lead recovery(45.67%),with anode residues comprising 67.58%PbO_(2)and 32.42%PbO·PbSO_(4).Remarkably,this process exhibits significant economic and environmental advantages,with recycling 1 kg of SLP through the(NH_(4))_(2)SO_(4)-NH_(3)·H_(2)O suspension electrolysis process resulting in a net profit of 0.3466 USD and a reduction in carbon emissions of 119.758 kg CO_(2)eq.,offering dual advantages of environmental and economic benefits.This work provides fundamental insights into lead phase conversion during suspension electrolysis while presenting a practical,effective solution for battery recycling industries.展开更多
基金sponsored by the National Natural Science Foundation of China(No.22276153).The authors would like to thank the Shiyanjia Lab for the XRD test.
文摘Spent lead paste(SLP)presents a major recycling challenge in lead-acid battery treatment due to its insoluble lead compounds.This study develops an innovative and environmentally sustainable approach by integrating(NH_(4))_(2)SO_(4)-NH_(3)·H_(2)O with suspension electrolysis,effectively converting poorly soluble PbSO_(4)into soluble[Pb(NH_(3))_(4)]^(2+)complexes.The electrolytic conversion mechanisms of SLP components are systematically elucidated,revealing four distinct transformation pathways:1)metallic Pb undergoes complete dissolution as[Pb(NH_(3))_(4)]^(2+)complexes followed by cathodic reduction to elemental lead;2)PbO_(2)increases after suspension electrolysis since part of PbO is oxidized;3)PbO demonstrates dual behavior,with 45.74%undergoing anodic oxidation to PbO_(2) while the remainder(54.26%)participates in cathodic electrodeposition;4)PbSO_(4)exhibits triple conversion routes,including:1)32.98%transformation through intermediate(NH_(4))Pb(OH)SO_(4)formation followed by anodic conversion to PbO·PbSO_(4),2)21.36%direct cathodic reduction to metallic lead,and 3)the residual fraction maintaining soluble[Pb(NH_(3))_(4)]^(2+)speciation in the electrolyte.The optimized process achieves exceptional current efficiency(95.49%)and lead recovery(45.67%),with anode residues comprising 67.58%PbO_(2)and 32.42%PbO·PbSO_(4).Remarkably,this process exhibits significant economic and environmental advantages,with recycling 1 kg of SLP through the(NH_(4))_(2)SO_(4)-NH_(3)·H_(2)O suspension electrolysis process resulting in a net profit of 0.3466 USD and a reduction in carbon emissions of 119.758 kg CO_(2)eq.,offering dual advantages of environmental and economic benefits.This work provides fundamental insights into lead phase conversion during suspension electrolysis while presenting a practical,effective solution for battery recycling industries.
