JP2003183082A - Amorphous refractory material and amorphous refractory - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an amorphous refractory material capable of improving spalling resistance without damaging slag erosion resistance, and also provide an amorphous refractory excellent in slag erosion and spalling resistances. <P>SOLUTION: This amorphous refractory material includes refractory aggregate, nickel oxide or nickel powder, partially stabilized zirconia powder and a hydraulic binder. The amorphous refractory is obtained by adding water to the above refractory material to make a kneaded material, and then firing the formed kneaded material. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an amorphous refractory raw material and an amorphous refractory, and more particularly to a blast furnace, a converter, an electric furnace,
The present invention relates to an amorphous refractory raw material and an amorphous refractory used for lining in a kiln such as a cupola, a heating furnace, an incinerator, and a discharge gutter and a pan for treating a high-temperature melt.

[0002]

2. Description of the Related Art Conventionally, in the above-mentioned applications, an amorphous refractory material is often used as an inner lining. In addition, in order to improve the slag erosion resistance of amorphous refractories, chromium oxide is also added to the amorphous refractory raw material, but hexavalent chromium is generated at the time of use. Improvement is desired.

Against this background, in recent years, amorphous refractories without addition of chromium oxide have been developed. For example, in Japanese Unexamined Patent Publication No. 2001-80969, an amorphous refractory composed of a nickel-alumina-based material is used. The object is JP 2000-
Japanese Unexamined Patent Publication No. 281455 discloses an amorphous refractory made of an alumina-zirconia-based material.

[0004]

However, although the alumina-based material is relatively stable chemically, α-
The coefficient of thermal expansion of Al ₂ O ₃ is 8.8 × 10 ⁻⁶ , which is relatively large among inorganic materials, and has some disadvantages with respect to spalling resistance. For example, operation is performed intermittently. When installed in a gasification melting furnace, there is a concern that cracks and peeling may occur due to repeated heating and cooling cycles.

The present invention has been made in view of the above points, and has an amorphous refractory material capable of improving spalling resistance without impairing slag erosion resistance, and slag erosion resistance. And an amorphous refractory having excellent spalling resistance.

[0006]

In order to achieve the above object, the present invention comprises a refractory aggregate, nickel oxide powder or nickel powder, partially stabilized zirconia powder, and a hydraulic binder. The present invention provides a characteristic amorphous refractory material, and an amorphous refractory material obtained by adding water to the irregular refractory material to prepare a kneaded product and firing the molded kneaded product.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.

The amorphous refractory raw material according to the present invention contains, as essential components, refractory aggregates, ceramic fine powder, nickel oxide powder or nickel powder, partially stabilized zirconia powder, and hydraulic binder.

Examples of the refractory aggregate used in the present invention include alumina-based refractory aggregates, silicon carbide-based refractory aggregates, and mixtures thereof. Of these, the alumina refractory aggregate reacts with nickel oxide powder or nickel powder to produce a spinel-type alumina-nickel oxide compound,
It is preferable because it enhances the slag erosion resistance of the amorphous refractory.

When only silicon carbide type refractory aggregate is used as the refractory aggregate, if alumina fine powder is contained as the ceramic fine powder described later, the fine alumina powder and nickel oxide powder or nickel are used. A powder is preferable because it produces a spinel-type alumina-nickel oxide compound and the refractory obtained in the same manner has high slag erosion resistance.

The material of the alumina refractory aggregate is, for example, one or two selected from high purity alumina, alumina silica, mullite, bauxite and chamotte.
There are more than one species. Here, the alumina-silica broadly includes a composition mainly composed of an alumina component and a silica component, and the mullite is a mullite that contains the alumina component and the silica component in a predetermined mixing ratio. Say.

The above-mentioned alumina-based refractory aggregate may contain other components in addition to the alumina-based material, but those containing a higher proportion of the alumina-based material are preferable from the viewpoint of heat resistance (fire resistance).

The material of the silicon carbide refractory aggregate is, for example, silicon carbide for refractory having a purity of 80% or more.

The above-mentioned alumina refractory aggregate or silicon carbide refractory aggregate can be used alone or in combination of two or more kinds.

As the refractory aggregate, those having a particle diameter of more than 50 μm are used, and any material having a particle diameter within this range may be used. It is preferable to use a mixture of particles having different particle diameters because the obtained amorphous refractory material has a dense internal structure, and the kneading property of the kneaded material is improved by the oil effect, so that the kneaded material is easily poured into the construction site.

For example, as the refractory aggregate, a coarse-grained material having a particle diameter of more than 1 mm and not more than 7 mm and a particle diameter of 0.15 mm
It is preferable to mix a fine particle material having a particle diameter of more than 1 mm and less than 1 mm with a powder material having a particle diameter of more than 50 μm and less than 0.15 mm. When such refractory aggregates with different grain sizes are combined, fine particles enter the voids between the coarse particles forming the skeleton in the irregular-shaped refractory, and further, the powder material is used between the coarse particles and the fine particles. Since it enters into the voids, the denseness of the obtained irregular shaped refractory can be improved. In addition, the powder material also acts as a lubricant that enhances the fluidity of the kneaded material, improves the fluidity of the kneaded material, and is easily poured into the construction site.

The refractory aggregate is preferably contained in the amorphous refractory raw material in a proportion of 48 to 80% by mass, similarly to a general irregular refractory material. When the refractory aggregate is composed of the above-mentioned coarse-grained material, fine-grained material, and powdered material, the coarse-grained material is preferably 25 to 45% by mass in the amorphous refractory raw material.
More preferably 28 to 40 mass%, fine particle material preferably 15 to 35 mass%, more preferably 20 to 30 mass%, powder material preferably 4 to 25 mass%, more preferably 5 to 22 mass%. Should be included in. When the coarse-grained material, the fine-grained material and the powdered material are blended in the above proportions, the internal structure of the obtained refractory material is densified, and the fluidity of the kneaded material is improved so that the kneaded material is easily poured into the construction site.

The ceramic fine powder used in the present invention is used for improving the workability of a kneaded product obtained by adding water to an amorphous refractory raw material and kneading it, that is, increasing the fluidity and water retention of the kneaded product and increasing the viscosity. To lower the. Examples of the ceramic fine powder include fine powders of alumina, silica, titania, zirconia, silicon carbide and the like.

Examples of the material of the alumina fine powder include the same materials as the above-mentioned alumina refractory aggregates. For example, one or more selected from high purity alumina, alumina silica, mullite, bauxite and chamotte. Is mentioned. The fine alumina powder may contain other components in addition to the fine alumina powder, but it is preferable that the fine alumina powder contains the fine alumina powder in a higher proportion from the viewpoint of heat resistance (fire resistance). Examples of the material of the silicon carbide fine powder include the same materials as the above-mentioned silicon carbide refractory aggregates, and examples thereof include silicon carbide for refractories having a purity of 80% or more.

Among the ceramic fine powders, the alumina fine powder is a spinel type fine powder which imparts fluidity to the kneaded product and enhances the slag erosion resistance of the amorphous refractory by reacting with the nickel oxide powder or the nickel powder. Preferred because it produces an alumina-nickel oxide compound. Also,
Silica fine powder is preferable because it imparts fluidity and water retention to the kneaded product and also ensures sufficient strength after heating of the amorphous refractory material. Further, by mixing and using the alumina fine powder and the silica fine powder, the kneaded product has high fluidity and water retention, and further, the alumina fine powder produces a spinel type alumina-nickel oxide compound and silica fine powder. A powder is more preferable because it has sufficient strength after heating the refractory. The ceramic fine powder may be used alone or in combination of two or more.

The average particle size of the ceramic fine powder is 0.1 to
The thickness is 50 μm, preferably 0.1 to 30 μm, more preferably 0.1 to 10 μm. When the average particle size is within the above range, the internal structure of the obtained amorphous refractory material is densified, the fluidity of the kneaded material is improved, and the kneaded material is easily poured into the construction site.

Since the fine ceramic powder is smaller than the powder material of the refractory aggregate, it can easily penetrate into any gaps between the refractory aggregates when firing the irregular refractory material. Therefore, when the alumina fine powder is used as the ceramic fine powder, it reacts with the nickel oxide powder or the nickel powder in these gaps to produce a spinel-type alumina-nickel oxide compound rich in slag erosion resistance. Erosion due to slag that tends to occur in the gap can be more effectively suppressed.

The ceramic fine powder is preferably 12 to 27% by mass in the raw material for the amorphous refractory material, and more preferably 1% by mass.
It is contained in an amount of 4 to 27% by mass. If the content of the ceramic fine powder is less than 12% by mass, fluidity and water retention of the kneaded material of the amorphous refractory raw material are not sufficient, which is not preferable. Particularly, in the fine alumina powder, if the blending amount is less than 12% by mass, the spinel-type alumina-nickel oxide compound may not be sufficiently formed. If the amount of kneading water is increased to impart fluidity and water retention to the kneaded product in this state, the refractory aggregate and the ceramic fine powder are easily separated, which is not preferable. If the amount of the ceramic fine powder blended exceeds 27% by mass, the fluidity of the kneaded material of the amorphous refractory raw material when vibration is applied is improved,
It is not preferable because the viscosity of the kneaded material increases too much and the workability deteriorates.

When the ceramic fine powder is a combination system of alumina fine powder and silica fine powder, the compounding amount of the fine alumina powder in the amorphous refractory raw material is preferably 8 to 2.
6.5% by mass, more preferably 10 to 25% by mass, the compounding amount of silica fine powder is preferably 0.5 to 10% by mass,
More preferably, the amount is 1.5 to 7% by mass. When the amount of the fine alumina powder and fine silica powder is within the above range, a kneaded product having an excellent balance of fluidity, water retention and viscosity can be obtained.

The nickel oxide powder or nickel powder used in the present invention is a component blended to impart slag erosion resistance to the amorphous refractory. Among them, the nickel oxide powder is, for example, used in catalysts, glass coloring, enamels, ceramic glazes, ferrite materials, and the like, and 75 mass% or more of powder in terms of nickel can be mentioned. Further, as the nickel powder, for example, nickel hydroxide,
Powders containing nickel compounds such as nickel chloride and nickel carbonate, and metallic nickel may be used, as long as they generate nickel oxide by heating in an oxidizing atmosphere.
Here, the heating in an oxidizing atmosphere means, for example, heating in a firing process of the kneaded molded product in air, drying, or heating when the amorphous refractory after firing is used in a furnace. Can be mentioned.

The nickel oxide powder or nickel powder has an average particle size of 0.1 to 100 μm, preferably 0.3 to 30.
The one with μm is used. When the average particle size is within the range, nickel oxide or nickel oxide produced by oxidation of nickel powder during firing or the like reacts with fine alumina powder or fine alumina aggregate to effectively form spinel alumina. -A nickel oxide compound is generated, and slag erosion resistance of amorphous refractory becomes high, which is preferable.

The nickel oxide powder or nickel powder is N
The mass in terms of iO is preferably 0.7 to 18% by mass, more preferably 1 to 15% by mass, particularly preferably 1.5 to 5% by mass, and further particularly preferably 1.8 in the amorphous refractory raw material. Contained in an amount of ˜4.5% by weight. If the blending amount is less than 0.7% by mass, the slag erosion resistance of the obtained amorphous refractory product is not sufficiently improved, which is not preferable. However, the blending amount is 0.7% by mass or more and 1.8% by mass.
If the amount is less than the above, the compounding amount may be small and the stability of quality may be deteriorated. Therefore, when importance is attached to the stability of quality during construction, the compounding amount may be 1.8% by mass or more. More preferable. Further, when the content is more than 18% by mass, it is uneconomical because the effect of improving the slag erosion resistance does not improve to a certain extent or more, which is uneconomical, and the molded body largely expands during firing, and cracks are likely to occur in the working body, which is preferable. Absent.

The partially stabilized zirconia powder used in the present invention is a component added to improve the spalling resistance of the amorphous refractory. The mechanism is considered to be that the metastable tetragonal phase transitions to the monoclinic phase (martensite transformation) near the tip of the crack generated by the thermal stress generated in the refractory material, and the fracture energy is absorbed and dispersed. The partially-stabilized zirconia powder may be zirconia partially stabilized by adding 1 to 10%, preferably 2 to 5% of CaO or MgO to the zirconia powder. The partially stabilized zirconia powder has an average particle size of 1 to 45 μm, preferably 5 to 20 μm. When the average particle diameter is within the range, it is easy to uniformly disperse in the matrix of the irregular shaped refractory, so that it is easy to absorb the breaking energy, and the effect of improving the spalling resistance with a small addition amount, and kneading This is preferable because the fluidity of the product is good.

The partially-stabilized zirconia powder is contained in the raw material for the amorphous refractory preferably in an amount of 2 to 10% by mass, more preferably 2 to 6% by mass, and particularly preferably 3 to 5% by mass. If the blending amount is less than 2% by mass, it cannot contribute to the improvement of spalling resistance. On the other hand, if the blending amount exceeds 10% by mass, the strength of the amorphous refractory after firing will be significantly reduced, which is not preferable.

The hydraulic binder used in the present invention is not particularly limited, but examples thereof include hydraulic alumina and alumina cement. Of these, hydraulic alumina does not contain CaO, so that even if the obtained amorphous refractory is repeatedly used at high temperature, the slag erosion resistance becomes particularly difficult to decrease, and the alumina component becomes nickel oxide powder or nickel powder. It is preferable because it reacts to form a spinel-type alumina-nickel oxide compound. The hydraulic binder has an average particle size of 1 to 20 μm, preferably 10 to
It is 15 μm. When the average particle size is within the above range, it is possible to maintain workable fluidity for 30 minutes or more after kneading, which is preferable.

The hydraulic binder is contained in the amorphous refractory raw material in an amount of preferably 2 to 10% by mass, more preferably 2 to 5% by mass. If the compounding amount of the hydraulic binder is less than 2% by mass, curing failure may occur when the working temperature is low, and if it exceeds 10% by mass, the curing may occur when the working temperature is high. It is not preferable because the fluidity at the time of kneading may be sharply reduced too early.

The amorphous refractory raw material according to the present invention may be further blended with an organic fiber or a dispersant as appropriate. Examples of the organic fiber include polypropylene, acrylic, rayon, nylon, and vinylon, and these can be used alone or in combination of two or more. It is preferable to add an organic fiber, because it is possible to prevent the construction body from exploding during rapid heating. The blending amount of the organic fibers may be the same as that of a general irregular shaped refractory, and the refractory aggregate, the nickel oxide powder or the weight of NiO of nickel powder, the total amount of the ceramic fine powder and the hydraulic binder is 100 parts by mass. As opposed to
0.04 to 0.1 part by mass is preferable.

Examples of the dispersant include metal chelate compounds, alkali metal carbonates, condensed salts of aromatic sulfonic acid formalin, and the like, and these can be used alone or in combination of two or more. It is preferable to add a dispersant, since the fluidity of the kneaded product with a low amount of water is improved and kneading becomes possible. The blending amount of the dispersant is 0.05 to 0.5 parts by mass with respect to 100 parts by mass of the refractory aggregate, the mass of nickel oxide powder or nickel powder in terms of NiO, the total amount of the ceramic fine powder and the hydraulic binder. is there. It is preferable that the blending amount of the dispersant is within the above range because the fluidity of the kneaded product of the amorphous refractory raw material is maintained for a long time.

The amorphous refractory raw material according to the present invention contains the above-mentioned refractory aggregate, nickel oxide powder or nickel powder, ceramics fine powder and hydraulic binder, and if necessary, organic fiber or dispersant in a specified amount. And uniformly mixed to obtain. These raw materials may be mixed once or a plurality of times, and when mixing a plurality of times, the order of mixing does not matter.

In the amorphous refractory raw material according to the present invention, at least the ceramic fine powder preferably contains the alumina fine powder, and the ceramic fine powder contains the alumina fine powder and the refractory aggregate is the alumina refractory bone. It is more preferable to include a material. If the amorphous refractory raw material contains fine alumina powder, the fine alumina powder easily enters the gaps between the refractory aggregates when firing the amorphous refractory, and during firing or in a melting furnace, etc. When using, the spinel type alumina-nickel oxide compound having a high slag erosion resistance can be produced by reacting with the nickel oxide powder or the nickel powder in the gap. Therefore, it is possible to effectively suppress the erosion due to the slag that generally tends to occur in the gap. As a result, the slag erosion resistance of the obtained refractory material becomes higher. Further, when the alumina-based refractory aggregate is further included in addition to the alumina-based fine powder, when the alumina-based refractory aggregate is a powder material, the spinel is formed in the void formed by the coarse-grained material or the fine-grained material. Since a type alumina-nickel oxide compound is generated, the slag erosion resistance becomes higher, which is preferable.

The present invention also provides an amorphous refractory material. The amorphous refractory material of the present invention is a kneaded product obtained by adding water to the above-mentioned amorphous refractory raw material to prepare a kneaded product, and molding the kneaded product. Is obtained by firing in air. The amount of water to be added and the firing conditions are appropriately selected according to the composition of the amorphous refractory raw material.

As described in detail above, the amorphous refractory obtained contains a spinel type alumina-nickel oxide compound and has excellent slag resistance. Further, due to the presence of the partially stabilized zirconia, the spalling resistance becomes excellent.

[0038]

EXAMPLES The present invention will be further described below with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

(Examples 1 and 2, Comparative Example 1) Particle size is 1 mm
34.0 parts by weight of coarse particles of alumina refractory aggregate having a diameter of more than 7 mm and less than 3 mm, 30.0 parts by weight of fine particles of alumina refractory aggregate having a particle diameter of more than 0.15 mm and less than 1 mm,
11.5 parts by weight of a powder material of alumina refractory aggregate having a particle size of more than 50 μm and 0.15 mm or less, average particle size 2 μm
Fine powder of alumina of 11.0 parts by weight, average particle size of 0.6 μm
0.5 parts by weight of silica fine powder, 4 parts by weight of nickel oxide powder having an average particle size of 1 μm, 3.5 parts by weight of hydraulic alumina powder having an average particle size of 10 μm, 0.1 part by weight of a dispersant, and 0.04 of an organic fiber. 5 parts by weight of CaO partially stabilized zirconia powder (Example 1), 5.0 parts by weight of MgO partially stabilized zirconia powder (Example 2) or monoclinic zirconia powder 5 5 parts by weight of water was added to the mixture containing 0.0 parts by weight (Comparative Example 1), and the mixture was kneaded with a mixer for 6 minutes.

The kneaded product thus obtained was cast into a shape for each test shown below, aged at 20 ° C. and 80% humidity for 24 hours, then dried at 110 ° C. for 24 hours, and further 140
It was fired at 0 ° C. for 5 hours to obtain a test piece composed of an amorphous refractory material. The test pieces obtained were evaluated for spalling resistance (flexural strength) and slag erosion resistance. The results are also shown in Table 1.

(Spalling resistance) 40 mm × 40 mm
A test piece having a size of 160 mm was heated at 1300 ° C. for 30 minutes and air cooled for 30 minutes as one cycle, and this cycle was repeated for two cycles, and then the bending strength was measured. Then, the rate of decrease in strength was determined by comparing with the bending strength before the heat cycle.

(Slag erosion resistance) In order to evaluate the slag erosion resistance, the following (1) crucible erosion test and (2) are shown.
A rotary erosion test was performed.

(1) Crucible erosion test As shown in FIG. 1, a molten slag 20 is poured into a test piece 10 which is a cube having a side of 70 mm and a cylindrical space 11 having a diameter of 30 mm and a depth of 35 mm opened on the upper surface. And the whole is 15
Heated at 00 ° C. for 5 hours. Then, after cooling, the test piece 10
Was cut into two along the diameter of the void 11 and the residual slag height (H), the width (W) and the depth (D) of the eroded portion 30 were measured.

(2) Rotational erosion test As shown in FIGS. 2 and 3, a test piece having a trapezoidal cross section (upper base 55 mm of trapezoidal surface, lower bottom 130 mm of trapezoidal surface, trapezoidal surface height 65 mm, trapezoidal pillar The height of 114 mm) 40 pieces were joined together with the inclined surfaces 41, and fixed by combining them so as to form a hexagonal column-shaped space 43D on the six sides of the upper bottom rectangular surface 42. The body 45 was constructed. Then, the test body 45 is laid down sideways and mounted on the cylindrical rotating part (height 195 mm, diameter 400 mm) 50 of the rotating device, the molten slag 20 is held in the space 43, and the burner 60 is installed.
With the flame (LPG: O ₂ = 1: 6) of
It was continuously rotated at a rotation speed of 6 rpm at 1500 ° C. for 8 hours. After the lapse of 8 hours, the test piece 45 is attached to the individual test piece 40.
2, from the center line ab in the longitudinal direction of the upper bottom side rectangular surface 42 to the center line c in the longitudinal direction of the lower bottom side rectangular surface.
Cut along d. Then, as shown in FIG. 4, the average depth and area of the eroded portion A due to slag on the cut surface abcd were measured, and the erosion rate was calculated by the following formula. Erosion rate (%) = (area of erosion part A / total area of cross section before test) × 100

The chemical composition of the molten slag 20 used in the (1) crucible erosion test and (2) rotary erosion test (by a fluorescent X-ray analyzer manufactured by Rigaku Co., Ltd.) is as shown in Table 2.

[0046]

[Table 1]

[0047]

[Table 2]

As is apparent from Table 1, the test pieces of Examples 1 and 2 according to the present invention have a significantly higher spalling resistance than the test piece of Comparative Example 1 in which the partially stabilized zirconia powder is not used. And the slag erosion resistance is also improved.

[0049]

As described above, according to the present invention,
An amorphous refractory having excellent slag erosion resistance and spalling resistance can be obtained.

[Brief description of drawings]

FIG. 1 is a top view (A) and a sectional view (B) showing a test piece used in a crucible erosion test.

FIG. 2 is a perspective view showing a test piece used in a rotary erosion test.

FIG. 3 is a schematic diagram showing a structure of a rotating device used in a rotary erosion test.

FIG. 4 is a diagram for explaining an erosion rate in a rotary erosion test.

[Explanation of symbols]

10 test pieces 20 Molten slag 30 Erosion part 40 test pieces 43 vacant place 50 rotating parts 60 burners

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 4G033 AA01 AA02 AA06 AA07 AA24                       AB02 AB09 BA01                 4K051 AA01 AA02 AA03 AA05 AA06                       BE03

Claims (8)

[Claims] 1. An amorphous refractory raw material comprising a refractory aggregate, nickel oxide powder or nickel powder, partially stabilized zirconia powder, and a hydraulic binder. 2. The amorphous refractory raw material according to claim 1, further comprising ceramic fine powder. 3. The amorphous refractory raw material according to claim 1, wherein the nickel oxide powder or the nickel powder is 0.7 to 18% by weight in terms of NiO, and the partially stabilized zirconia powder is 2 to 10% by weight. % Refractory raw material characterized by containing%. 4. The amorphous refractory material according to claim 1, wherein the nickel oxide powder or nickel powder has an average particle diameter of 0.1 to 100 μm, and the partially stabilized zirconia powder has an average particle diameter of 0.1 to 100 μm. An amorphous refractory raw material characterized by being 1 to 45 μm. 5. The amorphous refractory material according to any one of claims 1 to 4, wherein the refractory aggregate includes an alumina refractory aggregate, and the ceramic fine powder includes an alumina fine powder. Amorphous refractory raw material. 6. The amorphous refractory material according to any one of claims 1 to 5, wherein the partially stabilized zirconia powder contains magnesium oxide or calcium oxide. . 7. An amorphous refractory product, which is obtained by adding water to the amorphous refractory raw material according to any one of claims 1 to 6 to prepare a kneaded product, and firing the formed kneaded product. 8. The amorphous refractory according to claim 7, wherein the amorphous refractory contains a spinel-type alumina-nickel oxide compound.