Regeneration Of Ruthenium Trichloride In Ruthenium Plating Waste Liquid

At present,the ruthenium in the geology and mineral resources are scarce.The ruthenium recovered from the secondary resource wastes accounts for a large proportion of industrial raw materials,and the recycling of ruthenium at home and abroad is particularly important,especially in industrialized countries.The huge demand for ruthenium resources has led to more wastes,so the demand for ruthenium recovery technology is becoming more urgent.In this paper,ruthenium-plated waste solution was used as raw material,and the recovery technology of ruthenium trichloride was studied by distillation-extraction combined method,liquid membrane and ionic membrane electrolysis.The best technological conditions of the three methods were obtained,which improved the social and economic benefits and reduced the consumption and waste of ruthenium resources.The first part is the regeneration of ruthenium trichloride from ruthenium-plated waste solution by distillation-extraction method.The influence of distillation and extraction conditions on the recovery of ruthenium trichloride was investigated.When the distillation temperature was 80?,distillation time was 60 min,H2SO4-KMn O4 was used as oxidation system,6mol/L HCl was used as absorbent,the distillation recovery could reach 89.87%.At this time,the steam residual solution was treated.When the pre-oxidant was 10%Na Cl O,the concentration of extraction agent(N503)was 30%,phase ratio was 1,the reverse extraction agent was 2mol/L Na OH,and the phase ratio of reverse extraction was 1,the maximum ruthenium reverse extraction rate was 80.39%.Compared with single distillation,the total recovery rate of regenerated ruthenium by distillation-extraction method was 96.90% and 7.9% higher.The ruthenium content of ruthenium trichloride was 38.80%.The second part is the recovery of ruthenium trichloride from ruthenium-plated waste solution by liquid membrane method.The extraction effect of emulsion liquid membrane is better than that of bulk liquid membrane.The optimum extraction conditions of ruthenium by emulsion liquid membrane method were investigated.Under the condition of 3 mol/L HCl,the volume ratio of N503,span 80,sulfonated kerosene and liquid paraffin was 9: 4: 84: 3,Roi=0.5,Rew=2 and after 20 min,the stripping agent was 2 mol/L Na OH,the way of demulsification was chemical-heating combined demulsification,the temperature of the water bath was 80?,the demulsification time was 40 min,and the dosage of demulsifier was 3 m L.At this time,the extraction rate was up to 95.41%,and the highest breaking rate was 63.37%.The third part was the regeneration of ruthenium trichloride from ruthenium-plated waste solution by ionic membrane electrolysis.First,ruthenium was electrodeposited by cation membrane,and then ruthenium trichloride was prepared by anion membrane.The feasibility of the method was proved and the optimum process conditions were determined.With titanium mesh as the cathode material,the electrolytic temperature was 35?,the current intensity was 0.05 A,the current density was 83.33 A/m2,the concentration of electrolyte was 1~1.5 g/L,the concentration of cathode solution was 1.106 g/L,polar distance was 30 mm and after 10 h,the deposition rate of Ru was up to 98.40%.At this time,the electrolysis temperature was 30?,hydrochloric acid concentration was 1.25 mol/L,current density was 250 A/m2,polar distance was 30 mm,electrolysis time was 3 h,the highest ruthenium trichloride recovery rate was 93.85%,the content of ruthenium was 37.42%,the highest current efficiency was 15.76%,and the lowest energy consumption was 17.33 k W·h/kg.In summary,comparing the three methods,the process parameters of traditional distillation absorption method were mature,distillation combined with the extraction could effectively improve the recovery rate of ruthenium trichloride.The emulsion liquid membrane was relatively novel and could be combined with other methods to obtain different types of products,the operation of this method was simple and the recovery rate was considerable.The ruthenium trichloride product prepared by ion-exchange membrane electrolysis had high purity and high quality.The method was economical,environmentally friendly,energy-saving,easy to realize industrial production,and had a good social prospect.