SU1401053A1 - Method of producing metallurgical flux - Google Patents

Abstract

The invention relates to the field of ferrous metallurgy, in particular, to methods for producing fluxes for open-hearth furnaces, a converter and a blast furnace. The purpose of the invention is to reduce the cost of producing the flux and increase its desulfurization ability. The method consists in introducing into the slag bowl simultaneously with the release of the final steelmaking slag a corrective, slag mixture from limestone, unbaked dolomite and bauxite with a ratio of their masses of 1: (0.05-0.1): (0 07-0.12). The mixture is introduced in the amount of 1.5-2.0 by weight of slag. The resulting flux reduces sulfur in the iron from 0.032 to 0.023-0.024%. 2 tab. ys ate

Description

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The invention relates to ferrous metallurgy, in particular, to methods for producing fluxes for martensitic furnaces, converters and blast furnaces.

The purpose of the invention is to reduce the cost of producing the flux and increase its desulfurizing ability.

The proposed method for producing a metallurgical flux includes using as a corrective composition of the slag an additive of a mixture of lime, unbaked dolomite and bauxite with a mass ratio of 1: (0, 1) :( 0.07-0.12), introducing the mixture into the slag cup simultaneously with the release into it of the final steelmaking slag in the amount of 1.5-2.0 mass of this slag.

The high consumption of the mixture and its additive during slag production ensure the production of a material consisting of individual pieces of 50–150 mm in size. When the slag bowl is tilted, the material is easily removed and does not require further preparation for particle size distribution (crushing, screening, etc.). ).

The use of lime in the mixture reduces the cost of flux as a result of the physical heat of the liquid slag used to decompose the lime. Entering the mixture of unfired dolomite and bauxite ensures the desulphurization ability of the flux and a decrease in its melting point.

When the ratio in the mixture of limestone and unbaked dolomite is more than 1: 0.05 not: an increase in the magnesia content of I in the flux composition is reached to values that ensure an increase in its desulfurization ability, with a ratio of less than I 1: 0, 1, the viscosity of the slag increases, which forms i by the melting of the flux. When the ratio of limestone and bauxite IB of a mixture is more than 1: 0.07, the granulometrical composition of the flux deteriorates, the mass fraction of conglomerates with a size of more than 150 mm rises to make it difficult to use the flux. When the ratio is less than 1: 0.12, the degree of calcination of limestone decreases, the content of the sub flux in the flux increases, which leads to a decrease in its desulfurization ability.

When the mixture consumption is less than 1.5 wt. means of preparing flux for further use. With a mixture flow rate of more than 2 mass of the final steelmaking slag, the degree of calcination is reduced.

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ka, which leads to a deterioration of the desulfurizing ability of the mixture.

Example. The 08SP steel is smelted in a 200-ton open-hearth furnace using a scrap process. Simultaneously with the start of slag production, a mixture of lime, unbaked dolomite, and bauxite begins to settle into the slag cup. In the process, the ratio of the components and the consumption of the mixture are changed. The optimization parameter uses the estimated value of the flux production costs, which includes the cost of the mixture, the costs associated with crane operations, the time spent by the process personnel, and the sulfide capacity of the resulting flux (theoretically possible maximum ratio of sulfur distribution between slag and metal).

The results of the experiments are presented in table. one.

When implementing the proposed method, a significant reduction in costs and a simultaneous increase in the sulfide capacity of the resulting slag is achieved.

Obtained by the proposed method, the flux has the following chemical composition,%: CaO 75-80; SiO2lO - 12; HOS 8-12; FeO 6-19; MgO 3-6; MnO 4-6; CAS0 8-9. Basically, a flux fraction of 50-100 mm.

The optimal chemical and granulometric composition of the flux ensures its high metallurgical activity and allows it to be used as a substitute for limestone in blast furnaces and open-hearth furnaces, and also as a substitute for lime in converters.

To study the degree of desulfurization of a metal using fluxes of different compositions, the following experiments are given. In a 40kg induction furnace, the limit cast iron is molten and brought to 1400 ° C. The melt is released into the ladle, at the bottom of which 4 kg of flux of each composition is preloaded. The initial sulfur content in the iron is 0.032%. The final sulfur content in the iron after processing it with a mixture is given in table. 2

Upon receipt of the metallurgical flux, according to the proposed method, not only the sulfide capacity of the slag is increased, but also the conditions are created for the realization of an increased sulfur absorption capacity, which is expressed in a decrease in the sulfur content in the iron.

Claims (1)

Invention Formula A method for producing a metallurgical flux, comprising introducing the final steelmaking slag into the slag cup 55 and the slag correction composition of the slag, cooling the slag before solidification, which is designed to reduce costs for the production of flux and increasing its desulphurisation capacity, as a corrective composition of the slag additive, use a mixture of limestone, unbaked dolomite and bauxite with a ratio of mass 1: (0.05-0.1): (0.07-0.12), which is introduced into the slag bowl simultaneously with the release into it of the final steelmaking slag in the amount of 1.5-2.0 mass of this slag. Table 1