Copper Dross Vacuum Distillation Separation Of Copper And Lead

Copper dross is the by-product generated in lead smelting processing, which contains valuable metals such as Pb, Cu, Ag, Bi, Sn, etc. According to the actuality of the copper dross treatment process, the vacuum distillation method (smelting process short, environment friendly, good working conditions, etc) is used to separate lead and copper in copper dross. Therefore, it can not only enhance the comprehensive utilization ratio of resources and economic benefits but also can reduce environmental pollution. So it can be named as a green processing that accord with the requirements of energy efficiency and clean production.The methods of lead smelting and the treatments of copper dross were emphatically reviewed. Studies on reduction of PbO in vacuum and the feasibility of separating copper and lead from the copper dross by vacuum distillation have been carried out in this paper. The thermodynamic calculations of reducing PbO in the copper dross on vacuum condition showed that the reaction of carbon restoring PbO could occur below563K (atmospheric pressure restore temperature), and the reaction rate would increase with the pressure going down. The result of separation coefficient and combination binary diagram indicated that separation of the copper and lead from copper dross in vacuum conditions was easy, and the content of copper in lead matte was less than0.2%. Then the factors that affect the evaporation processing and calculating the maximum theoretical rate of evaporation of Pb and PbS were carried out the kinetics studies.The effects of coke dosage, time and temperament on separation of copper and lead from copper dross in vacuum were discussed. And the results have demonstrated that copper and lead contained in copper dross can be separated by vacuum distillation method. At certain distillation temperature, the amount of evaporation lead was increasing with the time growing, until the lead up completely volatile. The higher of the distillation temperature, the faster of the evaporation rate of lead. Distillation time could be reduced by improving distillation temperature, but if the distillation temperature too high, it would also cause an increase of other metals in the lead. The optimum conditions for separating copper and lead from copper dross in vacuum are coke dosage of2%, vacuum pressure is10-15Pa, time is30min, and temperature is1273K. Under the optimum conditions, the content of copper in lead matte is0.23%, lead in copper matte is0.05%, and recovery radio of Pb and Cu are87.25%,88.03%respectively.