Steel ladle refining furnace steel making method adopting fluoride-free foam slag prepared from limestone

Abstract

The invention relates to the field of a metal melting process, in particular to a steel ladle refining furnace steel making method adopting fluoride-free foam slag prepared from limestone. The method comprises the following steps of (1) temperature regulation; (2) S removal and slag making; (3) detection and ladle hanging. In the steel making process, calcium carbonate is added for producing CO2 and high-activity CaO through high-temperature decomposition; the CO2 does not have pollution; CO2 bubbles float up to form foam slag; the foam slag reaches the thickness capable of realizing the complete arc submerging; the electric arc exposure and high-temperature slag line corrosion can be effectively prevented; meanwhile, the energy loss due to the electric arc exposure can be avoided; great noise generated by an electrode rod in the electric arc process can be effectively reduced; the foam slag layer can react with C in the smoke dust to generate CO, so that the operation environment pollution by C-containing smoke dust in the smelting process can be reduced; the high-activity CaO and FeS in steel liquid undergo a reduction reaction to produce CaS; the CaS is stably stored in the slag and can be removed, so that the S removal effect is achieved.

Description

technical field [0001] The invention relates to the field of metal smelting technology, in particular to a ladle refining furnace steelmaking method using limestone to make fluorine-free foamy slag. Background technique [0002] The energy of the arc formed by the gas discharge in the ladle refining furnace is very concentrated, and the temperature of the arc zone reaches above 3000°C. In the conventional arc heating process, CaF2 is added to make foaming slag (diluted slag) to submerge the arc at low temperature. The cost of CaF2 is high and in the The harmful gas SiF4 produced by the reaction in the furnace pollutes the environment, and the submerged arc effect of SiF4 foam slag is poor. Noise, a lot of carbon-containing smoke and dust generated during the metal smelting process, polluting the operating environment, when CaO is added to remove S in the steelmaking process, conventional CaO has low activity, slow dissolution rate in molten steel and effective reaction rate ...

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Problems solved by technology

[0004] The object of the present invention is to overcome the above-mentioned deficiencies existing in the prior art, and to provide a ladle refining furnace steelmaking method using limestone to make fluorine-free foam slag. In the refining furnace steelmaking method, in the ladle refining furnace (ladle refining furnace) smelting process, calcium carbonate is added to make foam slag submerged arc, which solves the problem that the existing CaF2. The high temperature corrodes the slag line, shortens the service life of the slag line, and at the same time, the exposure of the arc light causes energy loss and generates large noise. Conventional CaO has low activity, slow dissolution rate in molten steel and low effective reaction rate of sulfide in molten steel, thus Leading to the problem of large consumption of CaO when removing S

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