Calcium pressing refining slag for steel production and preparation method thereof

Abstract

The invention discloses calcium pressing refining slag for steel production and a preparation method thereof. The refining slag comprises the following components: 30-50% of CaO, 30-50% of Al2O3, not more than 6.0% of SiO2, not more than 2.0% of F<->, 4-6% of MgO, not more than 12% of alkali and not more than 5% of the balance. The production raw materials are industrial wastes rich in calcium oxide and alumina. The preparation method comprises the following steps: grinding the raw materials to powder, mixing according to a certain proportion, and pressing to blocky refining slag rich in CaO and Al2O3 at a predetermined particle size by a high pressure granulator. The refining slag, provided by the invention, has the advantages of stable performance, no degeneration, no water absorption, no dusting, low fluorine, convenience for storage and transportation, and convenience for environmental protection; slugging is promoted and the smelting time is reduced in a steel production process, and the molten steel is refined and desulfurized in a steel discharge process or in an LF furnace.

Description

technical field [0001] The invention belongs to the technical field of steelmaking production, and in particular relates to an aluminum-calcium refining slag for steelmaking and a preparation method thereof. Background technique [0002] In the existing LF furnace molten steel refining methods, there are mainly two kinds: one is to add lime into the molten steel tank while adding part of fluorite, or add lime and add part of bauxite and a small amount of fluorite, the other The first method is to add lime to the molten steel tank and add partly sintered or pre-melted calcium aluminate. In contrast, the refining process of lime plus part of fluorite or lime plus part of bauxite plus a small amount of fluorite is not easy to melt the lime due to the requirement of a certain particle size. Stone pollutes the environment and erodes the refractory material of the ladle; the refining process of lime plus sintered or pre-melted calcium aluminate improves the slag removal and refin...

AI Technical Summary

Problems solved by technology

In contrast, the refining process of lime plus part of fluorite or lime plus part of bauxite plus a small amount of fluorite is not easy to melt the lime due to the requirement of a certain particle size. Stone pollutes the environment and erodes the refractory material of the ladle; the refining process of lime plus sintered or pre-melted calcium aluminate improves the effect of slag removal and refining, but the cost of raw materials is relatively high

[0003] Chinese patent CN97121984.2 discloses a formula of low-silicon-content aluminum-calcium slag and its manufacturing method. The high content of S and Si in raw coke leads to a decrease in its sulfur capacity coefficient, which limits its desulfurization effect and is not conducive to deep desulfurization of molten steel

[0004] Chinese patent CN02120744.5 discloses a pre-melted low melting point calcium aluminate composite desulfurizer and its preparation method. Since the composite desulfurizer must be passivated first and then melted during the production process, the process is cumbersome and the cost is high

[0005] Chinese patent CN200710023020.0 discloses a desulfurizer for pre-melting vacuum smelting and its preparation method. The desulfurizer adopts the method of pre-melting first and then mixing ingredients. The components are prone to unevenness and unstable effect, and The process is more cumbersome and the cost is higher

[0006] Chinese patent CN200310103105.1 discloses a pre-melted refining purifier and its production process. Although the pre-melted molten steel cleaner has achieved a certain desulfurization effect, the erosion of refractory materials caused by the high fluorite content is not only Seriously affects the service life of furnace lining or molten steel tank lining, and is not conducive to environmental protection, so the application is greatly restricted