The Simulation Of Multi-fields In The DC For Zinc Smelting Submerged Furnace

With the development of zinc hydrometallurgy, more zinc powder is required for the purification process. Comparing with other technologies, the zinc powder produced by electric furnace is always cheaper and has higher activity and more extensive sources, so it becomes the main method to produce zinc power. However, the design and controlling of the smelting process often depended on the semi-empirical or empirical method because the underlying physical mechanism in furnace was not understood. So, the thermal processes in the submerged furnace were numerically simulated to obtain the effect of geometrical and processing parameter on the smelting process. The simulated results presented a theory support for the optimal design and controlling.The direct current submerged furnace with single anode and three anodes were studied respectively. For the case of the single anode, a three-dimensional electromagnetic model was developed the physical fields, such as voltage and current density distribution, at constant resistivity and variable resistivity as temperature were compared. The results show that the effect of resistivity on the physical field concentrated on the zone near the electrode, and the relative variation rate of the parameter was less than5%. For the constant power, the effect of the cathode length submerged in the melt on the physical field was analyzed. The results indicate that with the increase of cathode length submerged, there are more even distributions of current density, Joule heat density and electromagnetic force.Moreover, the temperature and velocity field in the submerged furnace with single anode were further studied. The results show the melt velocity driven by buoyancy(1.7×10-1m/s) is more larger than that by electromagnetic force(2.5×10-6m/s), so buoyancy is the main driving force. The temperature fields simulated in effective thermal conductivity model, Laminar flow model, k-ε model and RNG k-ε model was analyzed. Considering the characteristics of melt flow and temperature distribution in real industrial furnace, RNG k-ε model is thought to be more appropriate than other models.A three-dimensional model was developed for a direct current submerged furnace with three anodes, and the electromagnetic field, temperature field and velocity field were simulated. The results show that, for the constant power, if the distance between anode and the center increases, the volt increase, and current density, Joule heat density, electromagnetic force, temperature and velocity distributed more uniformly. For the upper part of the melt, the parameter distribution in the furnace with single anode is quite similar to that in the furnace with three anodes. But for the lower part of the melt, there are more uniform distribution of the temperature and velocity in the furnace with three anodes, which is beneficial for improving the effective volume of the furnace. Pictures53. Tables20. References71.