Molten iron dephosphorization agent manufactured by using converter dry-method dust-removal ash as raw material

Abstract

The invention discloses a molten iron dephosphorization agent manufactured by using converter dry-method dust-removal ash as a raw material, which belongs to the technical field of steel making and molten iron pretreatment and is applicable to converter molten iron dephosphorization treatment. The dephosphorization agent comprises the following chemical components in percentage by weight: 45 to 65 percent of CaO, 15 to 35 percent of iron oxides (Fe2O3+FeO), 5 to 15 percent of CaF2 and 2 to 6 percent of SiO2, wherein the ratio of CaO to Fe2O3+FeO+CaF2 ranges from 1.0 to 3.0, and the ratio of CaO to SiO2 ranges from 9 to 16; and the hemispherical fusion temperature of the dephosphorization agent is not more than 1,200 DEG C. The raw material of the dephosphorization agent comprises 20 to 60 percent of converter dry-method dust-removal ash, 20 to 60 percent of active lime powder and 5 to 20 percent of fluorite powder. The dephosphorization agent has the advantages that: after the converter molten iron dephosphorization pretreatment is performed by using the dephosphorization agent, the P content can be kept below 0.030 percent; the converter dry-method dust-removal ash is recycled in a steel making process; and the cost of the converter dephosphorization pretreatment is reduced considerably.

Description

technical field [0001] The invention belongs to the technical field of steelmaking and molten iron pretreatment, and in particular relates to a molten iron dephosphorization agent using converter dry dust removal as raw material. Background technique [0002] The continuous development and progress of the society has led to an increasing demand for high-quality clean steel. Since the traditional ladle, torpedo tank car powder spraying dephosphorization process + converter slag-less refining process cannot meet the process requirements for large-scale, low-cost production of clean steel, converter dephosphorization The process flow of phosphorus pretreatment + less slag refining process to produce clean steel has been promoted and applied. The process flow of clean steel produced by converter dephosphorization pretreatment + less slag refining process is characterized by utilizing the characteristics of high-efficiency smelting of converters to realize mass production of clea...

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Problems solved by technology

Although the thermodynamic advantages of dephosphorization pretreatment in the molten iron stage are obvious, but due to the relatively low treatment temperature, lime slagging is relatively difficult and the rate of lime slagging is low. In order to achieve a certain slag alkalinity, lime consumption will be relatively high. Realize the smelting target of dephosphorization pretreatment final slag alkalinity of 2.0~2.5 and molten iron [P] less than 0.03% after dephosphorization pretreatment, lime consumption generally reaches 25kg / t~35kg / t, ore consumption 20kg / t~30kg / t, fluorite consumption is 3kg / t~5kg / t

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