用甲基磺酸体系电积铅试验研究

Electrolytic Deposition of Lead in Methanesulfonic Acid Media

研究了采用甲基磺酸(MSA)体系电积铅,考察了磷酸用量、木质素磺酸钙用量、温度、极间距、电解液循环速率、电流密度、游离甲基磺酸浓度、铅离子浓度和阳极材料等对槽电压、电流效率、能耗、精铅形貌和阴阳极电位的影响。结果表明:适当提高体系温度、游离甲基磺酸浓度、电解液循环速率,可有效降低能耗;但温度过高会降低电流效率;减小极间距可有效降低槽电压;添加木质素磺酸钙可有效抑制枝晶生长,获得表面平整阴极铅;在磷酸用量2 g/L、木质素磺酸钙用量2 g/L、温度40℃、极间距35 mm、电解液循环速率300 mL/min、电流密度200 A/m^(2)、游离甲基磺酸浓度1 mol/L、Pb^(2+)浓度1 mol/L、以石墨为阳极条件下,电流效率达99.73%,能耗为593 kW·h/t,阴极铅结构致密、表面光亮。

The electrowinning lead in methanesulfonic acid system was studied.The effects of phosphoric acid mass concentration,calcium lignosulfonate mass concentration,temperature,electrode spacing,electrolyte circulation rate,current density,free methanesulfonic acid concentration,lead ion concentration and anode material on cell voltage,current efficiency,energy consumption,fine lead morphology and cathodic and anodic potential were examined.The results show that increasing electrolytic temperature,free methanesulfonic acid concentration and electrolyte circulating rate,the energy consumption can be effectively reduced,but the current efficiency decreases when electrolytic temperature is too high.Reducing the pole spacing can effectively reduce the slot voltage.The addition of calcium lignosulfonate can effectively inhibit growth of lead dendrite and obtain cathode lead with flat surface.Under the conditions of phosphoric acid of 2 g/L,calcium lignosulfonate of 2 g/L,temperature of 40℃,electrode spacing of 35 mm,electrolyte circulation rate of 300 mL/min,current density of 200 A/m^(2),free methanesulfonic acid concentration of 1 mol/L,Pb^(2+)concentration of 1 mol/L,graphite plate as anode,the current efficiency is 99.73%and energy consumption is 593 kW·h/t.The cathode lead plate with compact structure and bright surface can be obtained.