3D Numerical Analysis of the Arc Plasma Behavior in a Submerged DC Electric Arc Furnace for the Production of Fused MgO

Abstract

A three dimensional steady-state magnetohydrodynamic model is developed for the arc plasma in a DC submerged electric arc furnace for the production of fused MgO. The arc is generated in a small semi-enclosed space formed by the graphite electrode, the molten bath and unmelted raw materials. The model is first used to solve a similar problem in a steel making furnace, and the calculated results are found to be in good agreement with the published measurements. The behavior of arcs with different arc lengths is also studied in the furnace for MgO production. From the distribution of the arc pressure on the bath surface it is shown that the arc plasma impingement is large enough to cause a crater-like depression on the surface of the MgO bath. The circulation of the high temperature air under the electrode may enhance the arc efficiency, especially for a shorter arc.

Synthesis of reactive MgO from reject brine via the addition of NH4OH

“…calcination temperature and residence time. Fused MgO is produced above the fusion temperature of MgO (2800 °C) and has the lowest SSA and reactivity, which is excellent in chemical stability and moisture resistance (Wang et al, 2012). Dead-burned MgO is obtained at calcination temperatures above 1400 °C and has a very low SSA and reactivity.…”

Study on the influence of different contents of impure CaO on the process of electromelting magnesia

“…then manually adjust the upper and lower positions of the electrode and the distance between the electrode and the furnace wall; and turn on the power to start the arc and add bulk material to the electrode in the furnace chamber and smelt by submerged arc until the current is stable and the temperature in the furnace chamber is well distributed (Yang, 2016;Qi et al, 2010;Wang, 2021;Dong, 2008).…”

“…turn on the power to start the arc and add bulk material to the electrode in the furnace chamber and smelt by submerged arc until the current is stable and the temperature in the furnace chamber is well distributed (Yang, 2016; Qi et al , 2010; Wang, 2021; Dong, 2008).…”

“…Different contents of calcium oxide were added to lightly burned magnesium oxide, and the content of CaO is 1.5%, 2%, 2.5%, 3% and 3.5%, respectively. They are respectively labeled as sample A, B, C, D and E. The specific experimental process: first, a layer of material is laid at the bottom of the magnesium electric furnace, and some carbon blocks are added at the bottom of the electrode center; then manually adjust the upper and lower positions of the electrode and the distance between the electrode and the furnace wall; and turn on the power to start the arc and add bulk material to the electrode in the furnace chamber and smelt by submerged arc until the current is stable and the temperature in the furnace chamber is well distributed (Yang, 2016; Qi et al , 2010; Wang, 2021; Dong, 2008). …”

Synthesis of reactive MgO from reject brine

“…calcination temperature and residence time. Fused MgO is produced above the fusion temperature of MgO (2800 °C ) and has the lowest SSA and reactivity, which is excellent in chemical stability and moisture resistance (Wang, Wang et al 2012). Dead-burned MgO is obtained at calcination temperatures above 1400 °C and has a very low SSA and reactivity.…”