Steel-making device and steel-making method

Abstract

The invention provides a steel-making device and a steel-making method. The steel-making device comprises a pre-heating device, an electric-arc furnace, a refining device, a middle smelting device anda continuous casting machine, wherein the pre-heating device is provided with a feeding inlet and a discharging outlet; the electric-arc furnace comprises a furnace housing, the furnace housing is provided with a feed inlet and a steel outlet, the feed inlet is communicated with the discharging outlet, and the bottom of the furnace housing is provided with a first stirring device for stirring molten steel. The refining device is provided with a liquid inlet and a liquid outlet, and the liquid inlet is communicated with the steel outlet; the middle smelting device is provided with an inlet andan outlet, the inlet is communicated with the liquid outlet, and the middle smelting device is internally provided with a filter assembly; the continuous casting machine is provided with a feed inletand a steel outlet, and the feed inlet is communicated with the outlet. In the steel-making device, it is not required that steel ladles are transferred, in the steel-making process, dynamic continuous running can be achieved, the production period is shortened, and the yield is increased.

Description

technical field [0001] The invention relates to the technical field of metallurgy, in particular to a steelmaking equipment and a steelmaking method. Background technique [0002] With the accelerated development of science and technology, the quality requirements for steel are also increasing day by day. Thin plates require good deep drawing performance, thick plates require uniform performance throughout the thickness, and pipes require high transverse impact values...all of which require sulfur and phosphorus in steel , hydrogen, nitrogen, and silicon, manganese, aluminum and other oxides and non-metallic inclusions produced during the deoxidation process, the removal is reduced to a few parts per 100,000 or a few parts per million, or even a few parts per million for ultra-clean steel to eliminate detrimental effects on steel properties. [0003] According to the technological process, steelmaking can be divided into two forms: long process and short process, among whic...

AI Technical Summary

Problems solved by technology

[0012] Consteel (US5400358-1992) is a horizontal continuous feeding technology, which can realize stable arc smelting in electric arc furnaces, is environmentally friendly and reduces electrode consumption, and can greatly reduce the production process costs of electric arc furnaces. However, in this method, only the upper layer of scrap steel is heated, so The preheating effect of scrap steel is not good. According to reports at home and abroad, the average energy-saving effect is only 25kwh per ton of steel; The length of the hot section, the total length of the equipment can reach 90-100m, which is very unfavorable for the layout of the workshop; thirdly, the dynamic sealing of this scheme has serious air leakage, and the capacity requirements for fans, etc. are relatively large

[0013] The hot flue gas of Consdie Electric Arc Furnace flows against the scrap steel in the preheating device. Since the scrap steel cannot be filled in the horizontal preheating device, a large part of the air flow flows in the upper part of the scrap steel layer, so that the scrap steel at the bottom is preheated. The thermal effect is poor, in order to achieve higher heat exchange, a 60-meter-long preheating tunnel is usually required

Since there are chlorine-containing compounds in scrap steel, such as PVC, etc., in theory, these chlorine-containing compounds will produce dioxins when they are incompletely burned below 800°C, especially in the range of 300-500°C. Dioxins, due to the long preheating tunnel of the Consdie furnace, the temperature continues to drop after the heat exchange between the hot flue gas and the scrap steel, so that the chlorine-containing compounds in the scrap steel are extremely easy to burn under incomplete combustion between 300 and 500°C. Produce dioxins and pollute the environment

But its inherent disadvantages are: 1. Although its inventor Intel Steel Corporation believes that the Consteel process developed by the company can preheat scrap steel to about 500 ° C, the equipment supplier Italy Dexing Company also advertises that it can preheat scrap steel To 400 ℃ ~ 600 ℃, and the production practice of Kyoei Steel (that is, the Japanese steel company) shows that the temperature of the scrap steel after preheating is uneven (high up and down), and the temperature of the scrap steel at 600mm ~ 700mm from the surface < 100℃, its energy-saving effect is only 25kwh / t steel, and the heat transfer efficiency is very low

The production practice of Consteel electric arc furnace in use in China also proves that the scrap steel preheating temperature of this equipment is low, and the energy saving effect is poor

2. The length of the equipment is very long. Generally, the total length of the preheating channel and the loading conveyor is about 60 meters. It occupies a large area. It is very difficult to install the equipment and transform the old factory building, and the one-time investment is very high.

3. The amount of air leakage is large, and a large amount of wild wind is mixed into the flue gas, which not only increases the burden on the dust removal fan, but also greatly hinders the recovery and utilization of the waste heat of the flue gas

4. The operating rate of the electromagnetic crane for loading materials is very high, some reaching over 90%, and sometimes the production will be affected due to loading

[0017] Among them, the molten steel ladle is transported from the electric arc furnace workshop to the refining process, from the refining process to the vacuum treatment process, and from the vacuum treatment process to the continuous casting process. The molten steel ladle undergoes multiple transfers, resulting in huge fluctuations in the temperature of the molten steel, and at the same time resulting in a production rhythm. The intermittent cycle production is not conducive to the stability of continuous casting production. At the same time, it causes a huge loss of molten steel heat, increases the tapping temperature of the electric arc furnace, increases the energy consumption of the electric arc furnace, and shortens the service life of the refractory material of the electric arc furnace.

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