(186h) Numerical Analysis of Effect of Diaphragm Structure Based on Thermo-Electro-Magneto-Hydrodynamics Coupling Model in Magnesium Electrolysis cell

Magnesium production is one of the most energy-intensive industrial processes. Like the Hall-Herault process of aluminum production, The core reactor is the electrolysis cell and its electrolysis efficiency is a crucial factor that profoundly affects the amount of energy consumed. Thus the energy consumption and current efficiency are crucially important indexes.

In the newly designed electrolysis process, magnesium oxide is dissolved in a rare earth chloride-containing electrolyte and electrolyzed to produce magnesium and oxygen gas similar to the production of aluminum [1] and lithium [2] in electrolytic cells. Considerable research efforts are reported on the use of commercial software to simulate flow field[3,4], thermoelectric field [5–7] and magnetohydrodynamic models [8] in magnesium electrolysis cells.

To improve the circulation of the electrolyte, a baffle plate were set between the electrolysis department and collect department. The ratio of the quantity of magnesium droplets in the metal separating compartment during the primary circulation to the whole quantity of magnesium droplets generated at the cathode is defined as the primary separation rate of magnesium droplets (PSR)[10]. In order to improve the electrolysis efficiency, the cell needs to increase its primary separation rate of magnesium droplets.

This work concerns the optimization of the electrolysis cell based on a three-dimensional thermo-electro-magneto-hydrodynamics coupling model. The flow field of mathematical model was validated by the cold model experiments of PIV in the previous research[9]. The structure of the diaphragm and buffle plate were studied to improve the PSR. The PSR could increase from 18% to 40% after optimizing the structure and position of the diaphragm and buffle plate.

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