JPS63117975A - Water system monolithic refractories for molten iron pretreatment vessel - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] <Industrial Application Field> This invention is applicable to pouring materials for blast furnace gutters, stamp materials, pig iron mixers,
This product relates to hot metal pretreatment containers used for hot metal ladle repair materials, mortar, etc., and river water-based monolithic refractories.

<Prior art> In recent years, blast furnace TLs, pig iron mixers, hot metal pots, etc. have not only increased the output of a as a result of larger blast furnaces, but have also come to serve as refining vessels for desiliconization, dephosphorization, etc. The mainstream of monolithic refractories is /V2O3SLCC materials.

Monolithic refractories for hot metal pretreatment vessels used under such severe conditions (hereinafter referred to as 1p monolithic refractories)
Metal powders such as aluminum and silicon are added to improve strength through densification of the structure, prevent oxidation, and provide corrosion resistance. causes a hydration reaction, which poses a risk of blistering during construction and explosion or cracking when the construction body is heated, and the amount of metal powder added was limited to 0.5% by weight at most.

A method of adding boric acid etc. as a measure to suppress the hydration reaction of this metal powder (Japanese Patent Application Laid-Open No. 53-66917),
Method of adding methylhydrogen polysiloxane (JP-A-60)
-226461) or a method of coating metal powder with resin (for example, Japanese Patent Application Laid-Open No. 55-9568)
Publication No. 1, etc.) have been disclosed.

<Problems to be Solved by the Invention> Although the problems of monolithic refractories for hot metal pretreatment containers have been improved to some extent by the various methods described above, there is still insufficient C′, and a complete solution has not yet been achieved. It's not.

Therefore, monolithic refractories that do not use water are also being considered (Japanese Patent Laid-Open No. 145080/1983).

Further, when the amount of metal powder, particularly metal aluminum, added is increased due to such a hydration reaction inhibitor, the formation of carbides is observed. The formation of carbides has improved the strength and corrosion resistance due to the densification of the structure, but on the other hand, the stress relaxation function has deteriorated, causing the Ill weave to become emulsified and causing peeling under thermal and mechanical stress. , metal insertion and peeling wear and tear have started to be seen.

Therefore, water-based monolithic refractories are emerging that are easy to use and economical, and also have corrosion resistance, oxidation resistance, spalling resistance, and toughness. desired.

<Means for Solving the Problems> The present inventors added metal powder and vitreous material together to a carbon-containing refractory, thereby improving strength and corrosion resistance through the interaction between the metal powder and vitreous material. They found that the addition of this glassy material also had the effect of suppressing hydration of the metal powder, and succeeded in solving the above-mentioned problems. ,
This invention has been completed.

That is, this invention uses 0.5 to 10 parts by weight of metallic aluminum powder to 100 parts by weight of a refractory material consisting of 40 to 98% by weight of alumina raw material, 1 to 50% by weight of silicon carbide, and 1 to 20% by weight of carbon material. or 1 to 15 parts by weight of mixed powder or alloy powder of metallic aluminum and metallic silicon;
This is a river water-based monolithic refractory for pre-treatment of hot metal, which is characterized in that it is used by adding a binder and water to a composition containing 0.5 to 10 parts by weight of a glassy material.

<Function> The monolithic refractory of the present invention is a refractory material made of an alumina raw material, silicon carbide, and a carbonaceous material, to which metallic aluminum powder and a vitreous material are added, and if necessary, metallic silicon powder. Some components in the glassy material added at temperatures around room temperature dissolve in the added water and react with the surface of the metal powder to form a dense film that is insoluble in water. It is thought that this prevents the hydration reaction of the metal powder.

Then, when the construction body is heated, a phenomenon occurs in which one or both of the added metal powder and the glassy material melt in a medium temperature range of 400 to 1000°C, and the other melts. At the same time as the metal reduces the glassy components, the metal is oxidized and becomes a metal oxide, and the volume expansion at that time closes the pores and blocks the inflow of air from the outside into the refractory. Prevents oxidation of carbonaceous +A 1F31.

Further, a part of the added metal replaces the elements constituting the glassy substance, thereby increasing the viscosity of the glassy substance, and the oxidation prevention effect of the coating with the glassy carbonaceous material continues up to a high temperature range.

At the same time, the oxidized metal reacts with other components in the glass and with the refractory material components, forming a new mineral phase, which precipitates and bonds with the refractory components, strengthening the bond between the refractory particles. As a result, the strength of the entire refractory is improved.

The reduction of the glassy material constituents by the metal and the precipitation of the mineral phase due to the reaction of the oxidized metal with the glassy component are faster than the dissolution of the aggregate particles into the glass, so the glassy material This prevents deterioration of the quality of the aggregate and deterioration of the properties of the matrix due to the dissolution of the aggregate particles into the glass, which would otherwise occur if only 10% of the aggregate was added. Furthermore, the coexistence of the glassy material suppresses the formation of carbide due to the reaction between the added metal powder and the carbonaceous material. That is, the reaction of metallic aluminum to aluminum carbide is prevented, and the brittleness of the structure is prevented. Furthermore, in the case of blast furnace gutters, especially since tapping is intermittent, deterioration of refractories due to digestion of aluminum carbide is prevented. It is.

Furthermore, depending on the type of glass, the component reduced by the metal and the carbonaceous material may react to form carbide, further strengthening the bond. For example, SL O! in silicate glass!
This is the case, for example, when SiC whiskers become SiC whiskers after being reduced.

Furthermore, unlike binders, the added glassy materials and metal powders are movable when softened and melted, filling the gaps between the aggregate particles due to capillary action and causing mineral changes, so that they can move between the particles. As the antennae become obtuse, the concentration of stress is alleviated, and as a result, the matrix has excellent structural stability, improving corrosion resistance, spalling resistance, and abrasion resistance. Such characteristics are highly desirable for molten metal containers that are repeatedly heated and cooled.

Of course, when metal powder is added alone, the oxidation resistance and strength of large materials also improve due to pore clogging caused by the formation of oxides due to air oxidation of the metal. In the composition of this invention, the contribution of the interaction effect between metal and glass is greater.

<Structure of the Invention> The refractory materials used in the water-based monolithic refractories of this invention are alumina, silicon carbide, and carbonaceous materials,
For alumina FA format, the amount used is 40 to 98% by weight of fused alumina, sintered alumina, sillimanite, bauxite, etc. If it is less than 40% by weight, the corrosion resistance of alumina cannot be exhibited. Moreover, if it exceeds 98% by weight, the spalling resistance will be poor, which is not preferable.

Silicon carbide has the effect of suppressing the oxidation of carbon and fully exhibiting the high corrosion resistance and high spalling resistance of carbon, and the amount used is 1 to 50% by weight, and if it is less than 1% by weight, the oxidation resistance, The effect on volume stability is weak, and 50
If it exceeds % by weight, the tissue strength will decrease and workability will also decrease.

Examples of carbonaceous materials include natural graphite, artificial graphite, petroleum coke, casting coke, various pitches, carbon black, etc., and the amount used is 1 to 20% by weight, and 1% by weight.
If it is less than 20% by weight, the corrosion resistance and spalling resistance will be poor, and if it is more than 20% by weight, the mechanical strength will be low and the wear resistance will be poor.

Aluminum and, if necessary, silicon are used as metal powders added to these refractory materials. Metallic aluminum powder reacts with oxygen gas in the pores to form an oxide, blocking the pores and preventing densification and oxidation of carbon dioxide. At the same time, the molten material reacts with the glassy material, but the oxidation of the glassy material Some types have poor fluidity and poor reactivity with aluminum and glass. Adding metallic silicon to this lowers the melting point of metallic aluminum and improves its fluidity, making it easier to contact and react with glassy materials. Of course, silicon also contributes in the same way as aluminum.

If aluminum and silicon are used together, a mixed powder may be used, but it is more preferable to use an alloy powder because the melting point will be lower.

The amount of metal powder added is 0.5 to 10 parts by weight per 100 parts by weight of the refractory material when only metal aluminum is added, and 1 to 15 parts by weight when used in combination with silicon.
Part by weight. The mixing ratio of aluminum and silicon is preferably 1 part aluminum to 1 part silicon or less by weight. If the amount of metal added is less than the lower limit, the effect of the addition will not be exhibited, and if it is more than the upper limit, the corrosion resistance will be poor, which is not preferable.

Furthermore, various types of glass such as silicate glass, phosphate glass, borate glass, aluminate glass, borosilicate glass, borophosphate glass, and titanate glass can be used as the glassy material, and they can be heated at temperatures of about 400 to 1000℃. A material that softens and melts when exposed to humidity is desirable. If the melting temperature is high, the reaction between the metal and the glass, which is a feature of the present invention, is difficult to occur. Among these glasses, borosilicate glass, borophosphate glass, and phosphate glass are particularly effective.Furthermore, compared to other glass materials, borosilicate glass has increased strength, oxidation resistance, and It is particularly effective to use borosilicate glass together with borosilicate glass or phosphate glass, since corrosion resistance and stress relaxation ability are significantly improved, and borosilicate glass and phosphate glass significantly prevent hydration of metal powder. The amount of these glassy materials used is 0.5 to 10 parts by weight per 100 parts by weight of the refractory material; if it is less than 0.5 parts by weight, the oxidation resistance will be poor, and if it is more than 10 parts by weight, the corrosion resistance will be poor. Not desirable because it is inferior.

The water-based monolithic refractory of this invention is based on the above materials,
By adding binders, peptizers, dispersants, water reducers, etc. and adding water to the normal particle size formulation, it is possible to repair blast furnace II pouring materials, stamping materials, pig iron mixers, blowing pipes for hot metal pots, etc. It can be used for shrines, mortars, etc. At that time, it is best to use commonly used binders depending on each case, so there is no need for special techniques. It's something you get.

<Example> Hereinafter, this invention will be explained in detail with reference to Examples.

Tests were conducted on pouring materials having the formulations shown in Table 1. The poured samples were dried at 110° C. for one day and night, and then tested as shown in Table 1.

Toughness value is 3 at 1000℃ and 1400℃ in reducing atmosphere.
Measure and find the stress-strain curve using the point bending test method.
child .

The slag test uses a rotating slag test method to determine the slag composition.
Lo, 17% by weight, #2 (h9% by weight, Fe050% by weight, Ca020% by weight, I'bO4% by weight, 150
The test was carried out at 0°C for 5 hours.

The oxidation test was conducted using a silicon carbide heating element electric furnace at temperatures of 1000° C. and 1200° C. for 5 hours each in an air atmosphere.

Note that the toughness value ratio, the erosion area ratio, and the decarburized area ratio are expressed as a ratio with one of the comparative examples being 100.

Table 2 shows the test results for spraying materials, and Table 3 shows the formulations and test results for mortar tests. The test was conducted by pouring the water-containing formulation shown in the table into a frame in the same manner as for pouring materials.

Table 1 Table 2 Table 3 Table 3 <Effects of the invention> As is clear from the results in Tables 1 to 3, the monolithic refractories to which metal powder and vitreous material are added together are as good as those to which only metal powder is added. It can be seen that the toughness and oxidation resistance are superior compared to those of the other materials, and the toughness, oxidation resistance and corrosion resistance are significantly superior to those containing only glassy material. Also,
In the case of poured materials, the appearance observation after drying at 110°C showed that the examples of this invention showed very excellent results with no explosions, cracks, or blisters; As a result, the adhesion rate was almost 100, the same as the conventional product.
%, the adhesive strength is sufficient when used as mortar, and the oxidation resistance and corrosion resistance of this invention are high, so the preliminary erosion of brick joints has been considerably alleviated. Excellence is clearly visible.

In this way, the water-based monolithic refractory of the present invention in which metal powder and glassy material are added together shows no hydration reaction of the metal powder even when water is used, and the carbonaceous material softens and melts due to the softening and melting of the glassy material. A part of the molten glass fills between the particles, and the product of reaction between the molten glass and the molten metal powder causes rapid crystallization of the glass substance, resulting in significantly improved oxidation resistance. In addition, the bond between particles was also strengthened, and at the same time, the stress relaxation function was significantly impaired due to the increase in toughness. Furthermore, the workability is no different from conventional products. As a result, the operational stability and durability of the hot metal pretreatment vessel, which were unsatisfactory with current materials, are significantly improved.

Claims (4)

[Claims] (1) Alumina raw material 40-98% by weight, silicon carbide 1-1
50% by weight of a fireproof material consisting of 1 to 20% by weight of a carbon material, 0.5 to 1 part by weight of metal aluminum powder
1. A water-based monolithic refractory for a hot metal pretreatment vessel, characterized in that it is used by adding a binder and water to a composition containing 0 parts by weight and 0.5 to 10 parts by weight of a glassy material. (2) Alumina raw material 40-98% by weight, silicon carbide 1-1
Contains 1 to 15 parts by weight of a mixed powder or alloy powder of metal aluminum and metal silicon, and 0.5 to 10 parts by weight of a vitreous material per 100 parts by weight of a refractory material consisting of 50% by weight and 1 to 20% by weight of a carbon material. 1. A water-based monolithic refractory for a hot metal pretreatment vessel, which is used by adding a binder and water to a composition. (3) Claim 1 or 2, characterized in that the glassy material is one or more selected from the group consisting of borosilicate glass, phosphate glass, and borophosphate glass. Water-based monolithic refractories for hot metal pretreatment vessels. (4) Claim 1, characterized in that the glassy material is one or two selected from the group consisting of borosilicate glass, phosphate glass, or borophosphate glass.
The hot metal pretreatment vessel river water system monolithic refractory according to item 1 or 2.