RU2239521C2 - Lining slag formation preventing material for filling discharge ducts of steel casting ladles and method for making it - Google Patents

Abstract

FIELD: foundry.

SUBSTANCE: lining slag formation preventing material includes silica-containing sand and carbon base anti-sintering component in quantity 0.5 - 2.0%. Method for preparing such material is performed at using as carbon base component hydrocarbons with coke residue more than 50%, for example coal tar or pitch. Method comprises steps of heating components until 500-800C; filtering generated sublimates through sand layer under pressure caused by said sublimates and depositing them on sand particles in the form of semi-coke film. Such film prevents agglomeration of sand grains at casting metal.

EFFECT: enhanced reliability of opening discharge duct of ladle.

2 cl, 2 ex

Description

The invention relates to the field of ferrous metallurgy and can be used in steelmaking in the manufacture of a mixture to fill the outlet channels of steel pouring ladles.

A known mixture for filling the exhaust channels of steel pouring ladles, including silica sand and an anti-sintering component in the form of graphite [1] and soot [2] with a carbon content in the mixture of 0.5-2.0%. These mixtures are obtained by mechanical mixing.

The disadvantage of these mixtures is that they are a mechanical mixture of two materials of different degrees of density and dispersion. When filling the channel, the mixture is poured from the height of the side of the bucket to its bottom. During the fall, the mixture is refracted and separated by density, as a result of which silica sand is at the bottom, graphite or soot at the top. This causes soot or graphite to escape into the metal when filling the bucket and sintering grains of sand, which makes it difficult to open the channel.

Known anti-skid material for exhaust channels of steel pouring ladles containing sand and anti-sintering material-soot. A method of preparing this material includes preparing the starting materials, thoroughly mixing the components of the mixture: silica sand with anti-sintering material - soot [3].

These inventions are closest in technical and taken as prototypes.

The disadvantages of the known technical solutions is that a mixture consisting of materials of different degrees of density and dispersion is refracted, and it must constantly be mixed.

The problem to which the invention is directed is to eliminate sintering of silica-containing sand grains and to increase the reliability of opening the channel without the use of oxygen.

The problem is achieved due to the fact that the proposed anti-skid material for the exhaust channels of steel pouring ladles, including silica sand and an anti-sintering component based on carbon in an amount of 0.5-2.05 wt.%, While the grains of silica sand are coated with a semi-coke film formed by the deposition on them of sublimates of hydrocarbons with a coke residue of more than 50%.

To obtain the proposed anti-skid material, a method is used that includes the preparation of starting materials consisting of silica-containing sand and a carbon-based component, while hydrocarbons with a coke residue of more than 50% are used as a carbon-based component, the components are heated to t = 500-800 ° C , the resulting sublimates from hydrocarbons are filtered through a layer of silica sand under the pressure formed by the sublimates, and deposited on the surface of the grains of sand in the form of a semicoke film.

The method is implemented in the following sequence.

The components of the mixture are placed in a container with an insulating lid, first hydrocarbons, which use coal tar or pitch, then silica sand. Raw periclase-lime products molded with a bundle of prepared resin can be used as a source of the prepared resin. When using tar or pitch, they are separated from the sand by a wireless grid.

When using periclase-lime products on a resin bond, they are backfilled with sand between the products. The container is installed in an oven and heated to t = 500-800 ° C.

In this case, the resulting sublimates of hydrocarbons are filtered through a layer of sand under the pressure formed by the sublimates, and are deposited on sand grains.

With further heating, the sublimates coke and form a strong film on the surface of sand grains.

A specific example of anti-skid material and a method for its preparation.

1. Periclase-lime products on a resin binder in bulk with silica sand containing SiO ₂ - 97.45 wt.% Were placed in a container, periclase-lime products were obtained by pressing calcined dolomite with a binder of prepared resin with a coke residue of 50%. After heating to 800 ° C for 40 hours, anti-skid material with a carbon content of 2.0% was obtained. The resulting material was used to fill the outlet channel of the steel pouring ladle. When the slide gate was opened, the anti-skid material spilled out, the metal was poured without oxygen.

2. A prepared coal tar with a coke residue of 55% was placed in a container. The resin layer was covered with a loose grid, onto which quartz sand was poured.

The container was closed with a lid and heated to 700 ° C for 10 hours. Received anti-skid material with a carbon content of 1.6%. The resulting material was filled up with the exhaust channel of the steelmaking ladle. When the slide gate was opened, the anti-skid material spilled out and the channel opened without the use of oxygen.

When using hydrocarbons with a coke residue of less than 50%, the carbon content in the anti-skid material is reduced and its effectiveness is reduced. So, when using a resin with a coke residue of 45%, the carbon content in the material decreased to 0.8%, and when using it, there were cases of using oxygen to open the channel.

At a heating temperature of less than 500 ° C, the formation of semicoke does not occur and the film on the grains of sand is easily destroyed. Heating above 800 ° C does not improve the quality of the material and is not economically feasible.

Sources of information

1. A.S. No. 1183294, B 22 D 41/08, 07/21/83

2. B.C. Sergienko, L.I. Krupman, V.P. Shevchenko. Development of technology for casting steel from ladles with slide gates. Steel, No. 11, 1978, p. 1004.

3. Patent EP 0598479 A1, B 22 D 41/46, 09.28.93.

Claims (2)

1. Anti-skid material for the exhaust channels of steel pouring ladles, including silica sand and an anti-sintering component based on carbon in an amount of 0.5-2.0 wt. %, characterized in that the silica-containing sand grains are coated with a semicoke film formed by precipitation of sublimates of hydrocarbons with a coke residue of more than 50%. 2. A method of manufacturing anti-skid material for the outlet channels of steel pouring ladles, including the preparation of starting materials consisting of silica sand and a carbon-based component, characterized in that hydrocarbons with a coke residue of more than 50% are used as a carbon-based component, the components are heated to a temperature 500-800 ° С, sublimates of hydrocarbons formed during heating are filtered through a layer of silica sand under the pressure created by sublimates, and precipitated on the surface sand grains in the form of a semi-coke film.