用于高效冶炼氧化镁的双电极直流电弧炉的仿真与实验

摘要

A 3 000kV·A three-phase AC arc furnace for MgO production has been elaborately refitted into a dual-electrode DC arc furnace with the same capacity. The relationship between the output voltage and the maximum arc length in different smelting currents has been studied. Meanwhile, the molten bath temperature field distribution was calculated by three-dimensional finite element simulation analysis method. High purity MgO crystals could be produced with the converted arc furnace. Additionally, the morphology of the molten MgO lump was similar to a tensile body with an elliptical cross section, which is consistent with the simulation results. Finally, the MgO smelting production data of DC arc furnace were compared with the data of AC arc furnace. The comparison results indicated that the dual-electrode DC arc furnace for smelting MgO has obvious advantages over the traditional three-phase AC arc furnace, from the views of energy consumption per ton, electrode loss as well as crystal purity. This paper has provided theoretical guidance and basis for the production of MgO with dual-electrode DC arc furnace.%将一台3000kV·A的三相交流氧化镁冶炼电弧炉改造成相同容量的双电极直流电弧炉。揭示了在不同冶炼电流下，输出电压与最大弧长之间的关系。同时，采用三维有限元法对氧化镁熔池的温度场分布进行仿真分析，得出熔池温度场的分布规律。利用改造后的电弧炉制得高纯度的氧化镁晶体，且冶炼得到的氧化镁熔坨的形貌近似椭圆形横截面的拉伸体，与仿真结果一致。最后，比较采用直流电弧炉和交流电弧炉冶炼氧化镁的生产数据，结果表明双电极直流电弧炉冶炼氧化镁的工艺，在单吨能耗、电极损耗以及晶体纯度等方面，均优于传统的三相交流电弧炉。本文工作为采用双电极直流电弧炉生产氧化镁提供了理论指导和依据。