A composite bottom-blowing multi-media system and method for bottom electrodes of DC electric arc furnaces

Abstract

The invention relates to a composite bottom-blowing multi-media system and method for the bottom electrode of a DC electric arc furnace, which belongs to the technical field of steelmaking and includes a plurality of bottom electrodes located at the bottom of the furnace, some of which are bottom-blown electrodes with a hollow structure, and some Bottom-blowing electrodes are one or more of Type I bottom electrodes, Type II bottom electrodes, and Type III bottom electrodes; Type I bottom electrodes: used to spray carbonaceous materials into the molten pool to carburize the molten pool and accelerate Scrap steel melting; Type II bottom electrode: used to spray slagging powder into the molten pool to form molten slag particles in the molten metal and increase the gas-slag-gold three-phase reaction interface area in the dephosphorization reaction process; Type III bottom electrode : It is used to inject gas into the molten pool to accelerate the mass transfer in the molten pool; it also includes a control unit connected to the bottom blowing electrode to realize online adjustment of injection parameters in combination with the power supply strength of the bottom blowing electrode during the smelting process. The invention can improve the production efficiency and reduce the consumption of raw and auxiliary materials.

Description

technical field [0001] The invention belongs to the technical field of steelmaking, and relates to a composite bottom-blowing multi-media system and method for a bottom electrode of a DC electric arc furnace. Background technique [0002] DC electric arc furnace steelmaking is one of the main methods of electric arc furnace steelmaking. The bottom of the furnace is used as the positive electrode of the arc current, and the stirring of the molten pool is strengthened by the action of the current between the electrodes, which improves the dynamic conditions of the molten pool to a certain extent. However, affected by its flat furnace structure, the stirring force of the molten pool is weak and the kinetic conditions are poor. The resulting problems such as long smelting cycle and control of phosphorus, nitrogen, and oxygen in molten steel have always restricted the green and efficient smelting of DC electric arc furnaces. development of. [0003] Mainly manifested in the foll...

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Problems solved by technology

[0002] DC electric arc furnace steelmaking is one of the main methods of electric arc furnace steelmaking. The bottom of the furnace is used as the positive electrode of the arc current, and the stirring of the molten pool is strengthened by the action of the current between the electrodes, which improves the dynamic conditions of the molten pool to a certain extent. However, affected by its flat furnace structure, the stirring force of the molten pool is weak and the kinetic conditions are poor. The resulting problems such as long smelting cycle and control of phosphorus, nitrogen, and oxygen in molten steel have always restricted the green and efficient smelting of DC electric arc furnaces. development of

[0003] Mainly manifested in the following aspects: 1) Raw materials such as scrap steel for smelting have complex structures, high nitrogen content, and large fluctuations in phosphorus content after melting; 2) Low carbon content in the molten pool, lack of carbon-oxygen reaction in the molten pool, and the flow rate of molten steel 3) During the smelting process, lime is usually added to the molten pool in the form of lumps, and the speed of slagging into slag is slow. Although the injection of carbon powder on the furnace wall improves the fluidity of slag, the carbon The utilization rate of powder is low, the consumption of raw and auxiliary materials is high, and the quality of molten steel is difficult to be effectively improved; 4) Modern electric arc furnace steelmaking generally uses high-power power supply to accelerate the melting of scrap steel and shorten the smelting cycle, while high-temperature arc ionization of N in the air 2 Make the molten steel easy to absorb nitrogen; 5) Strengthening the oxygen supply improves the smelting efficiency, but also brings about terminal overoxidation, low metal yield, and high alloy consumption after tapping; 6) The bottom electrode is used for power supply, and the furnace The local temperature at the bottom is too high, which limits the power supply strength and life of the bottom electrode

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