Study On Removal Of Zinc From Vacuum Distillation Of Copper - Nickel - Zinc Alloy Secondary Resources

As a kind of renewable resource, huge economic and social benefits can be achieved by recycling and reusing the alloy scraps of copper, nickel and zinc. Currently, wet separation is the main method to handle such alloy scraps, focused on the problems of traditional disposal method like big reagent consumption、long process、environmental pollution and large investment, this paper used the vacuum distillation experiment to investigate the copper、nickel and zinc alloy wastes so as to deal with this kind of material to provide a method of vacuum smelting which has the characteristics of high metal recovery, green environmental protection and short process.Firstly, a thermodynamic and dynamic research on removing the zinc from the alloy scraps with the method of vacuum distillation was conducted. Thermodynamic analysis shows that when the temperature was maintained during the range of 1023K-1323K, zinc can be easily removed from other components with vacuum distillation and zinc volatilized into the condensate, other components were enriched into the residue. Furthermore, the diffusion, evaporation and condensation behavior of zinc in vacuum distillation process was further analyzed from the perspective of dynamic analysis,and the maximum distillation rate of each component was calculated, the effect of temperature and system pressure on the evaporation rate of zinc was discussed.Secondly, vacuum distillation experiments were conducted in different temperature ranges, and the effect of distillation temperature, constant time and material layer thickness on the volatilizing behavior of zinc were investigated. Experiment results demonstrate that when the temperature was maintained from 1373K to 1573K, the further increasing of temperature has only a small impact on the volatilization rate of zinc, and when distillation was set at 1373K, constant time is kept to be 60min,system pressure is from lOPa to 30Pa, volatilization rate of zinc can reach as high as 99.93%, content of zinc in the residue can be reduced to 0.018%, so the temperature range should be reduced; During the low temperature range, when the temperature range was maintained from 1023K to 1323K, with the increase of temperature and time, the volatilization rate of zinc tended to increase apparently. Furthermore, when distillation temperature is set at 1273K, constant time is kept to be 90min,material mass is 90g, volatilization rate of zinc can reached as high as 99%,content of zinc in the residue can be reduced to 0.24% and condensation product of elemental zinc with the purity of 99% can be obtained.Finally, with the help of MATLAB software, the liquid surface of Cu-Ni-Zn three-dimensional phase diagram was plotted, in order to solve the problem that the alloy material does not melt but alloy of zinc was volatilized up.Mapping result shows that the original data can be quickly and accurately obtained in use of the GetData Graph Digitizer software, moreover, with the help of MATLAB software and using the method of regression, a smooth liquid surface was mapped out, which can fit out a small error range of curved surface equation, and can directly reflect from the liquid surface of this three-dimensional phase diagram when the distillation temperature was changed.