Power density control method for smelting fused magnesium through alternating current electric arc furnace

Abstract

The invention relates to a power density control method for smelting fused magnesium through an alternating current electric arc furnace. The power density control method comprises the following steps that (1) two-way distribution images of the temperature of the furnace surface are collected through thermal imagers; (2) the collected two-way images are synthesized into an integral temperature profile of the furnace surface through an image synthesizer; (3) the distribution of the temperature fields of the interior of a furnace body is calculated through finite elements; (4) the volume VT of a furnace hearth is calculated; (5) the power density is calculated through the power and the furnace hearth volume; (6) the weight of input ore is calculated; and (7) the lifting height of electrodes and the magnitude of the opening size of a valve are adjusted through proportion integration differentiation (PID) control according to the power density calculated in the step (5) and the state in the smelting stage and the weight of input ore of a material bin are combined, so that the power density is controlled. The control over the power density is achieved by changing the lifting height of the electrodes and the magnitude of the opening size of the valve. The defect of present control methods for smelting the fused magnesium through the alternating current electric arc furnace can be overcome through the power density control method. The per ton energy consumption of the electric arc furnace can be better reduced. The benefits are increased.

Description

technical field [0001] The invention relates to the technical field of smelting fused magnesium, in particular to a power density control method for smelting fused magnesium using an AC electric arc furnace. Background technique [0002] Fused magnesia is an important refractory material used in the metallurgical industry, usually using natural high-quality magnesite (MgCO 3 ), brucite (Mg(OH) 2 ), light-burned magnesia and dead-burned magnesia as raw materials are melted in a three-phase electric arc furnace. my country's magnesite is rich in resources and fine in texture. It is one of the dominant minerals and occupies an important position in the world. The process in which magnesite is thermally decomposed in an electric arc furnace to generate fused magnesium is essentially that magnesium carbonate is thermally decomposed into magnesium oxide and di [0003] The process of oxidizing carbon gas, its specific reaction formula is as follows [0004] [0005] The MgO...

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Problems solved by technology

[0006] At present, various control strategies control the rise and fall of the electrode to control the constant current, which belongs to constant power control. Its disadvantage is that the power density injected into the molten pool changes. With the continuous expansion of the molten pool, the power density injected into the molten pool The continuous reduction leads to uneven heat received by the molten pool, and the formed molten lump has a loose internal structure, low density, many impurities, and high energy consumption per ton.

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