Single-converter low-iron-consumption duplex less-slag smelting method

Abstract

The invention discloses a single-converter low-iron-consumption duplex less-slag smelting method, and belongs to the technical field of smelting and continuous casting. The method comprises the following steps that S1, a metal main material is put into a converter, and converter smelting is adopted; S2, the slag obtained after the decarbonization period serves as a slagging material, blowing desiliconization and dephosphorization are carried out in the converter, and slag charge is obtained; S3, deslagging is conducted, the deslagging amount is controlled to be 50%-70%, and semi-steel molten steel is obtained; S4, metallurgical limes and light-burned dolomite are added into the semi-steel molten steel for decarburization, the blowing end point of the converter is detected, when w[C] in the molten steel at the blowing end point is 0.06-0.10%, the temperature of the molten steel is 1620-1640 DEG C, the binary alkalinity is 2.5-3.0, and tapping is conducted immediately after the blowing is finished; S5, slag splashing converter protection is carried out after tapping, and the left slag is used as the slagging material for the blowing desiliconization and dephosphorization of the next converter. According to the method, the dephosphorization rate in the converter desilicication and dephosphorization periods is greatly increased, w[P] in chemical components of the converter end point molten steel is smaller than or equal to 0.030%, the dephosphorization pressure in the converter decarbonization period is greatly reduced, less-slag smelting of the molten steel is achieved, and the molten steel quality is good.

Description

technical field [0001] The invention belongs to the technical field of steel smelting and continuous casting, and in particular relates to a single-converter low-iron-consumption double-connection slag-less smelting method. Specifically, it involves controlling molten steel to reduce slag consumption and reducing Methods of heat loss, increasing the dephosphorization rate during the dephosphorization period and reducing the consumption of steel materials. Background technique [0002] At present, there are mainly two methods for smelting with less slag in the process of converter steelmaking at home and abroad: one is the double converter dephosphorization method, which uses two converters for smelting, the first one is used for dephosphorization, and the second one is used for dephosphorization. The decarburization treatment of molten iron after dephosphorization causes a large heat loss during the transfer of molten iron, and the addition of an additional converter increas...

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Problems solved by technology

[0003] Some iron and steel enterprises do not desiliconize and dephosphorize the molten iron because the phosphorus content in the molten iron is 0.18%. At the same time, the equipment and equipment of the converter cannot meet the requirements of dephosphorization by the double-connection method of the converter, and cannot meet the requirements of the converter slagging and dephosphorization of molten steel.

[0004] In the prior art, in the smelting process of "retaining slag + double slag" in a single converter, 1 / 2 of the slag is added in the desiliconization and dephosphorization stages of the converter to make slag, the dephosphorization rate is generally 60%, and the consumption of slag is high, and the slag High viscosity, large heat loss, and high phosphorus content in molten steel at the end of converter smelting

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