An innovative process was proposed for recovering lead from spent lead paste, and it produced less pollution and used lessenergy than the traditional process. First, lead dioxide in lead paste was reduced by glucose u...An innovative process was proposed for recovering lead from spent lead paste, and it produced less pollution and used lessenergy than the traditional process. First, lead dioxide in lead paste was reduced by glucose under hydrothermal conditions. Theeffects of the reaction time, glucose excess coefficient, temperature and pH on the hydrothermal reduction were systematicallyinvestigated. Under the optimized reduction conditions （i.e., temperature of 175 ℃, time of 120 min, glucose excess coefficient of3.0 and pH of 5.5）, 99.9% reduction ratio of lead dioxide is achieved, and only the PbO·PbSO4 and PbSO4 phases are observed in thereducing residue. Subsequently, the reducing residue is desulfurized in a NaOH solution, and approximately 99.40% of the sulfur isremoved. The main lead phase in the desulfurization residue is 3PbO·H2O.展开更多
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Project(2016M602427)supported by the Postdoctoral Science Foundation of ChinaProject(51504292)supported by the National Natural Science Foundation of ChinaProject(2016zzts288)supported by Graduate Student Innovation Foundation of Central South University,China
文摘An innovative process was proposed for recovering lead from spent lead paste, and it produced less pollution and used lessenergy than the traditional process. First, lead dioxide in lead paste was reduced by glucose under hydrothermal conditions. Theeffects of the reaction time, glucose excess coefficient, temperature and pH on the hydrothermal reduction were systematicallyinvestigated. Under the optimized reduction conditions （i.e., temperature of 175 ℃, time of 120 min, glucose excess coefficient of3.0 and pH of 5.5）, 99.9% reduction ratio of lead dioxide is achieved, and only the PbO·PbSO4 and PbSO4 phases are observed in thereducing residue. Subsequently, the reducing residue is desulfurized in a NaOH solution, and approximately 99.40% of the sulfur isremoved. The main lead phase in the desulfurization residue is 3PbO·H2O.
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.
