KR20190061528A - Binder composition for slag dart with improved workability - Google Patents

Abstract

The present invention provides a bonding agent composition for a slag dart with excellent workability, including: 50 to 80 wt% of first powder comprising a Na-containing inorganic compound and silica powder in a weight ratio of 20:80 to 95:5; and 20 to 50 wt% of second powder of at least one selected among a Mg-containing inorganic compound, magnesia, chromite, and spinel.

Description

[0001] BINDER COMPOSITION FOR SLAG DART WITH IMPROVED WORKABILITY [0002]

The present invention relates to a binder composition for a slag dart excellent in workability.

The slag dart is a spin-shaped refractory used to produce molten steel in the steelmaking process, and is mechanically inserted into the ladle at the end of the ladle to separate the molten steel and slag, thereby minimizing the slag flow into the ladle. Further, the slag dart is composed of a spin-shaped head portion and a circumferential leg portion serving as a guide.

The specific gravity of the slag dart is smaller than that of the molten steel and is larger than that of the molten slag. When the molten slag is introduced into the tapping hole at the end of tapping of the ladle from the converter, the molten steel and slag are separated by the dart, The inflow can be minimized.

Since the slag dart is used at a high temperature of 1600 DEG C or higher, which is the temperature at which the converter is heated, excellent refractivity is required and various refractories are currently being used. In addition, since the slag dart is charged at room temperature and rapidly heated to the ladle temperature, the slag dart should have excellent thermal shock resistance. In order to achieve the original purpose of improving the quality of steel by minimizing the slag inflow to the ladle, the slag dart has excellent durability against molten steel and slag Should be excellent.

The basic and acid neutral refractories are used singly or in combination to satisfy the characteristics of the above slag darts. However, the composite binder for darts currently used as a binder is limited to a range of extremely small added water, Is limited.

Further, the composite binder for dart used as a binder is disadvantageous in that it must be used in an acidic and basic manner depending on the constituent materials of the refractory for darts.

The present invention relates to a method of manufacturing a dart which is used to minimize the inflow of slag generated in a converter into a ladle when molten steel is introduced from a converter to a ladle during a steelmaking process To provide a binder composition for a slag dart.

One embodiment comprises 50 to 80% by weight of a first powder comprising a Na-containing inorganic compound and a silica powder in a weight ratio of 20: 80 to 95: 5; And

And at least one second powder selected from Mg-containing inorganic compounds, magnesia, chromium iron, and spinel.

The Na-containing inorganic compound may be selected from powdery sodium silicate, sodium hexametaphosphate (SHP), and mixtures thereof.

The Na-containing inorganic compound may have a purity of 95% or more.

The silica may be selected from fused silica, silica, silica fume, fly ash, cristoballite, tridymite, and mixtures thereof. The silica may have an SiO ₂ content of at least 60 wt%.

The Mg-containing inorganic compound may be selected from a Mg-containing nitride, a Mg-containing chloride, a Mg-containing sulfate, and a mixture thereof. The Mg-containing inorganic compound may contain a crystal number.

The magnesia may be selected from light magnesia, sintered magnesia, fused magnesia, and mixtures thereof.

The chrome iron may be selected from natural chrome iron, iron chrome iron and mixtures thereof.

The spinel may be selected from sintered spinel, fused spinel and mixtures thereof.

The binder composition for a slag dart solves the problem of a conventional composite binder for a dart so that the range of added water is wide and the influence on the constituent materials of the refractory for a dart is small so that the combination of constituent materials of the slag dart can be diversified But also the characteristics of the slag dart can be improved.

Hereinafter, embodiments of the present invention will be described in detail. However, it should be understood that the present invention is not limited thereto, and the present invention is only defined by the appended claims.

One embodiment comprises 50 to 80% by weight of a first powder comprising a Na-containing inorganic compound and a silica powder in a weight ratio of 20: 80 to 95: 5; And

And at least one second powder selected from Mg-containing inorganic compounds, magnesia, chromium iron, and spinel.

The mixing ratio of the Na-containing inorganic compound and the silica powder is preferably adjusted to 20: 80 to 95: 5 by weight. When the content of the Na-containing inorganic compound is less than 20% by weight, the binding strength is poor and the dry strength of the dart decreases. When the content of the Na-containing inorganic compound exceeds 95% by weight, the specific gravity of the dart decreases, The old closing ability is deteriorated.

The composition comprises 50 to 80% by weight of the first powder and 20 to 50% by weight of the second powder. If the content of the first powder exceeds 80% by weight, the corrosion resistance of the dart may be deteriorated. If the content of the first powder is less than 50% by weight, the binding strength may be insufficient and the dry strength of the dart may be reduced.

The Na-containing inorganic compound may be any Na-containing inorganic compound powder such as powdered sodium silicate, sodium hexametaphosphate (SHP), or the like. In order to minimize the influence of impurities, the purity is preferably 95% or more, and more preferably 97% or more.

The silica may be selected from fused silica, silica, silica fume, fly ash, cristoballite, tridymite, and mixtures thereof. It is preferable that the silica has a SiO ₂ content of 60 wt% or more. In this case, the dry strength of the binder composition can be improved.

The Mg-containing inorganic compound is not particularly limited and may be selected from a Mg-containing nitride, a Mg-containing chloride, a Mg-containing sulfate, and a mixture thereof. When the Mg-containing inorganic compound contains crystal water, it is easy to handle.

The magnesia is not particularly limited, and any of natural light and sea water magnesia among light magnesia, sintered magnesia and molten magnesia may be used.

The chrome iron is not particularly limited and may be selected from natural chrome iron, iron chrome iron and mixtures thereof.

The spinel is not particularly limited and may be selected from sintered spinel, fused spinel and mixtures thereof.

Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples. However, the following examples and comparative examples are for illustrative purposes only and are not intended to limit the present invention.

As shown in the following Table 1, the first powder and the second powder containing sodium silicate powder and fly ash as silica were mixed with an Na-containing inorganic compound to obtain a slag according to Examples 1 to 3, A binder composition for darts was prepared. In addition, Comparative Examples 1 to 4 were obtained by preparing binder compositions for slag dots in a range outside the scope of the Examples.

Example Comparative Example One 2 3 One 2 3 4 Na-containing inorganic compound: silica weight ratio 20:80 95: 5 50:50 10:90 100: 0 60:40 70:30 Second powder Spinel magnesia magnesia Spinel magnesia Spinel magnesia The content of the first powder (% by weight) 80 50 60 50 60 90 40 The content of the second powder (% by weight) 20 50 40 50 40 10 60

Darts were prepared using the binder compositions for slag darts according to Examples 1 to 3 and Comparative Examples 1 to 4. The darts were evaluated for the amount of applied water, density, dry strength and lid closing performance. The results are shown in Table 2 below. In Table 2, the amount of applied water means the minimum amount of water added to 100 parts by weight of the binder composition for a slag dart in order to ensure workability in the production of darts. In addition, the dry strength was the compressive strength value, and the lacustrine closing ability was applied to each of the 100 turning lanes.

Construction moisture requirement
(Parts by weight) 5.2 6.1 5.7 6.3 7.1 7.5 7.2 Density (g / cm ³⁾ 2.97 2.96 2.98 2.68 2.56 2.45 2.37 Dry strength (kg / cm ² ) 350 325 320 170 180 190 90 Lashing ability Great Great Great Bad Bad Bad Bad

From the results of Table 2, it can be seen that the binder composition for slag darts according to Examples 1 to 3 can secure an appropriate range of construction water content in comparison with the binder composition for slag darts of Comparative Examples 1 to 4, And the ability to close the louver opening is excellent.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, And falls within the scope of the invention.

Claims (9)

50 to 80% by weight of a first powder comprising a Na-containing inorganic compound and a silica powder in a weight ratio of 20: 80 to 95: 5; And
And at least one second powder selected from Mg-containing inorganic compounds, magnesia, chromium iron and spinel. The method according to claim 1,
The Na-containing inorganic compound is selected from powdered sodium silicate, sodium hexametaphosphate (SHP), and mixtures thereof. The binder composition for a slag dart is excellent in workability. The method according to claim 1,
The Na-containing inorganic compound has a purity of 95% or more, and is excellent in workability. The method according to claim 1,
Wherein the silica is selected from the group consisting of fused silica, silica fume, silica fume, fly ash, cristobalite, tridymite, and mixtures thereof. . The method according to claim 1,
Wherein the silica has a SiO ₂ content of at least 60 wt%, the binder composition being excellent in workability. The method according to claim 1,
The Mg-containing inorganic compound is selected from a Mg-containing nitride, a Mg-containing chloride, a Mg-containing sulfate and a mixture thereof. The method according to claim 1,
Wherein the magnesia is selected from light magnesia, sintered magnesia, molten magnesia, and mixtures thereof. The method according to claim 1,
Wherein the chromium iron ores are selected from natural chromium iron ore, melted chrome iron or mixtures thereof. The method according to claim 1,
Wherein the spinel is selected from sintered spinel, fused spinel, and mixtures thereof.