A Time-Dependent Multi-physical Field Coupling Model for Smelting Reaction Process in Ferronickel Submerged Arc Furnace
摘要
In this paper, a three-dimensional transient multi-physical field model considering the arc effect and the effect of component reactions on the furnace charge porosity was established to simulate the process of electrothermal conversion, heat and mass transfer, and ores reduction in the submerged arc furnace. The time-dependent solution of the electromagnetics-temperature-component multi-physical field was solved. Furthermore, the effects of electrode pitch circle diameter on the temperature distribution and component reactions were analyzed. The result shows that the electrical conductivity, electrical potential gradient, current density, Joule heat, and temperature are mutually dependent in the molten pool. Therefore, the multi-physical field exhibits transience, strong coupling, and non-uniformity. When the electrode center circle diameter increases from 4.1 to 4.9 m, the maximum temperature of the molten pool center decreases from 1751 K to 1247 K, and the high-temperature region moves toward outer side of the molten pool. Furthermore, the reaction mass of metal oxides shows a trend of first increasing and then decreasing. When the electrode center circle diameter increases from 4.1 to 4.5 m, the reaction region volume and reaction mass of nickel oxide increase by 4.1 and 3.7 pct, respectively. Then, the reaction mass of nickel oxide no longer increases significantly. When the electrode center circle diameter is 4.3 m, the reaction region volume and reaction mass of iron oxides reach the maximum, which are 43.07 m3 and 13332 kg, respectively. For optimizing the reaction mass of metal oxides, the suitable electrode pitch circle diameter can be of 4.3 to 4.5 m.