目的提高牺牲阳极的阴极保护法在酸性土壤中对接地网的防腐能力,分析牺牲阳极阴极保护法在酸性土壤中应用的技术要点,总结保护效果优化措施。方法设计牺牲阳极模拟系统,模拟地网面积为3.52 m2,保护电流设计为35.2 m A,对Q235碳钢和镀锌...目的提高牺牲阳极的阴极保护法在酸性土壤中对接地网的防腐能力,分析牺牲阳极阴极保护法在酸性土壤中应用的技术要点,总结保护效果优化措施。方法设计牺牲阳极模拟系统,模拟地网面积为3.52 m2,保护电流设计为35.2 m A,对Q235碳钢和镀锌钢两种常用接地材料的接地电阻、保护电位及保护电流进行研究。结果该方法对镀锌钢保护较好,保护电位均低于-0.95 V;对Q235碳钢保护较差,保护电位部分高于-750 m V,且波动较大,最大波幅可达201 m V。系统运行中,计算得出保护电流在降雨量较大时最高可达30.75 m A,降雨量较小时最低为11.89 m A,均低于设计值。结论由于阳极处砂石较多、土壤电阻率高,阳极不能完全释放电流。其次,土壤保水性差,电阻率波动大,系统运行不稳定也抑制了保护效果。酸性土壤盐基性离子大量淋失,土壤电阻率普遍较高,且受降雨扰动较大,牺牲阳极工作效率较低且稳定性差。需采用适当提高保护电流、降低阳极区土壤电阻率、优化阳极设计工艺参数等措施以达到良好的保护效果。展开更多
A novel treatment process of lead anode slime bearing high antimony and low silver was developed by a potential-controlled chloridization leaching and continuous distillation.The experimental results show a high Sb 3+...A novel treatment process of lead anode slime bearing high antimony and low silver was developed by a potential-controlled chloridization leaching and continuous distillation.The experimental results show a high Sb 3+ concentration,489.2 g/L,in the leaching solution for two-stage countercurrent leaching process,and the leaching rates of Sb,Cu,Bi more than 99% when the potential is controlled at 450 mV.When the leaching solution is distillated and concentrated at 120°C,almost all the silicon compound is evaporated into the concentration distillate and exists as amorphous hydrated silica.By the continuous distillation,high pure SbCl3 could be prepared,and AsCl3 is enriched in the distillate while metals Bi,Cu are enriched in the continuous distillation residue.As a result,the recovery rate of Sb is more than 95%.展开更多
A new anodic material of ternary Pb-0.8%Ag-(0-5.0%)Bi alloy for zinc electrowinning was obtained by doping Bi.The anodic oxygen evolution potential,corrosion rate,surface products after polarization,and microstructure...A new anodic material of ternary Pb-0.8%Ag-(0-5.0%)Bi alloy for zinc electrowinning was obtained by doping Bi.The anodic oxygen evolution potential,corrosion rate,surface products after polarization,and microstructures before and after polarization were studied and compared with those of Pb-0.8%Ag anode used in industry.The results show the anodic overpotential decreases with the increase of Bi content in the alloys.When the content of Bi is 1.0%(mass fraction),the anodic overpotential is 40-50 mV lower than that of Pb-0.8%Ag anode.While the corrosion rate decreases and then increases with the increase of Bi content.The Pb-0.8%Ag-0.1%Bi anode has the lowest corrosion rate(0.090 6 mg/(h·cm2).Doping Bi influences the structure of the anodic layer,but does not change the phase.The Pb-0.8%Ag-1.0%Bi anode layer is of a more fine-grained structure compared with Pb-0.8%Ag anode.展开更多
In this work, the effect of zinc addition on the performance of aluminium-based sacrificial anode in seawater was investigated. The parameters used in assessing the performance of the cast anodes are anodic efficiency...In this work, the effect of zinc addition on the performance of aluminium-based sacrificial anode in seawater was investigated. The parameters used in assessing the performance of the cast anodes are anodic efficiency, protection efficiency and polarized potential. The percentages of Zn in the anodes were varied from 1 to 8%Zn. The alloys produced were tested as sacrificial anode for the protection of mild steel in seawater at room temperature. Current efficiency as high as 86.69% was achieved at 6%Zn in the alloys. The polarized potential obtained for the couples(steel/Al based alloys) are as given in the pourbaix diagrams with the steel lying within the immunity region/cathodic region ( S-0.5V SHE) and the sacrificial anodes within the anodic region. The protection offered by the sacrificial anodes to the steel after the 7th and 8th week were measured. Protection efficiency values as high as 99.26% and 99.13% were achieved after the 7th and 8th with Al-6%Zn. The microstructure showed the intermetallic structures of β-phase which breakdown the alumina passive film and thus enhancing the anode efficiency.展开更多
文摘目的提高牺牲阳极的阴极保护法在酸性土壤中对接地网的防腐能力,分析牺牲阳极阴极保护法在酸性土壤中应用的技术要点,总结保护效果优化措施。方法设计牺牲阳极模拟系统,模拟地网面积为3.52 m2,保护电流设计为35.2 m A,对Q235碳钢和镀锌钢两种常用接地材料的接地电阻、保护电位及保护电流进行研究。结果该方法对镀锌钢保护较好,保护电位均低于-0.95 V;对Q235碳钢保护较差,保护电位部分高于-750 m V,且波动较大,最大波幅可达201 m V。系统运行中,计算得出保护电流在降雨量较大时最高可达30.75 m A,降雨量较小时最低为11.89 m A,均低于设计值。结论由于阳极处砂石较多、土壤电阻率高,阳极不能完全释放电流。其次,土壤保水性差,电阻率波动大,系统运行不稳定也抑制了保护效果。酸性土壤盐基性离子大量淋失,土壤电阻率普遍较高,且受降雨扰动较大,牺牲阳极工作效率较低且稳定性差。需采用适当提高保护电流、降低阳极区土壤电阻率、优化阳极设计工艺参数等措施以达到良好的保护效果。
基金Project(2006BAB02B04-4-1)supported by the National Science and Technology Pillar Program during the 11th Five-Year Plan Period,China
文摘A novel treatment process of lead anode slime bearing high antimony and low silver was developed by a potential-controlled chloridization leaching and continuous distillation.The experimental results show a high Sb 3+ concentration,489.2 g/L,in the leaching solution for two-stage countercurrent leaching process,and the leaching rates of Sb,Cu,Bi more than 99% when the potential is controlled at 450 mV.When the leaching solution is distillated and concentrated at 120°C,almost all the silicon compound is evaporated into the concentration distillate and exists as amorphous hydrated silica.By the continuous distillation,high pure SbCl3 could be prepared,and AsCl3 is enriched in the distillate while metals Bi,Cu are enriched in the continuous distillation residue.As a result,the recovery rate of Sb is more than 95%.
基金Project(2007SK2009)supported by the Science and Technology Research Project of Hunan Province,China
文摘A new anodic material of ternary Pb-0.8%Ag-(0-5.0%)Bi alloy for zinc electrowinning was obtained by doping Bi.The anodic oxygen evolution potential,corrosion rate,surface products after polarization,and microstructures before and after polarization were studied and compared with those of Pb-0.8%Ag anode used in industry.The results show the anodic overpotential decreases with the increase of Bi content in the alloys.When the content of Bi is 1.0%(mass fraction),the anodic overpotential is 40-50 mV lower than that of Pb-0.8%Ag anode.While the corrosion rate decreases and then increases with the increase of Bi content.The Pb-0.8%Ag-0.1%Bi anode has the lowest corrosion rate(0.090 6 mg/(h·cm2).Doping Bi influences the structure of the anodic layer,but does not change the phase.The Pb-0.8%Ag-1.0%Bi anode layer is of a more fine-grained structure compared with Pb-0.8%Ag anode.
文摘In this work, the effect of zinc addition on the performance of aluminium-based sacrificial anode in seawater was investigated. The parameters used in assessing the performance of the cast anodes are anodic efficiency, protection efficiency and polarized potential. The percentages of Zn in the anodes were varied from 1 to 8%Zn. The alloys produced were tested as sacrificial anode for the protection of mild steel in seawater at room temperature. Current efficiency as high as 86.69% was achieved at 6%Zn in the alloys. The polarized potential obtained for the couples(steel/Al based alloys) are as given in the pourbaix diagrams with the steel lying within the immunity region/cathodic region ( S-0.5V SHE) and the sacrificial anodes within the anodic region. The protection offered by the sacrificial anodes to the steel after the 7th and 8th week were measured. Protection efficiency values as high as 99.26% and 99.13% were achieved after the 7th and 8th with Al-6%Zn. The microstructure showed the intermetallic structures of β-phase which breakdown the alumina passive film and thus enhancing the anode efficiency.
