JPH02255577A - Monolithic refractory containing non-oxide - Google Patents

Abstract

PURPOSE:To prevent the elution of vitreous material into moisture, to obviate the deterioration of workability in kneading and to produce a sufficient effect of the vitreous material itself by coating the vitreous material for preventing the oxidation of carbon in the refractory with a resin having a high content of fixed carbon by prilling. CONSTITUTION:Borosilicate glass having <=0.1mm grain size is mixed as the vitreous material into molten pitch, the mixture is granulated by prilling using a pressurized nozzle-type granulator to obtain granules having <=0.5mm size. The granules are added into the refractory material by 1-20wt.%, and a refractory contg. non-oxides is obtained. Electric conductivity is not increased due to the elution of the vitreous component in this refractory, the fluidity is not deteriorated, the serviceable time is not shortened, and the workability is not deteriorated.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a method for lining a molten metal container with excellent corrosion resistance and
This article relates to monolithic refractories with spall resistance.

[Conventional technology]

Such monolithic refractories include carbon-containing refractories, but the construction of carbon-containing refractories has a problem in that their properties deteriorate during operation due to oxidation of the carbon contained therein. For this reason, in recent years, scaly graphite, which itself has excellent oxidation resistance, has been used as a carbon source.

However, monolithic refractories containing scaly graphite have poor formability, and it is necessary to add a large amount of moisture to maintain formability. As a result, the moisture content evaporates, creating air bubbles in the construction body, which reduces the strength of the construction body.

Corrosion resistance will deteriorate. Therefore, in order to maintain the quality of the construction body, it is not possible to use large amounts of scaly graphite, which has excellent oxidation resistance, and to increase the amount of carbon in refractories, it is difficult to use large amounts of scaly graphite, which has the disadvantage of poor oxidation resistance. However, it is necessary to use a pitch that can maintain workability even with a low moisture content, and there is a limit to the amount of pitch that can be used.

In order to improve this current situation, various measures have been proposed to prevent the oxidation of carbon content and increase the amount of carbon content. It is known from the publication that silicic acid glass, phosphate glass, and phosphoric acid glass are used.

However, although this simple arrangement of glass materials in molded refractories is effective in preventing carbon oxidation,
Amorphous materials that use water, such as castables, have the disadvantage that they are easily dissolved in water and that the elution of glass components significantly deteriorates workability.

[Problem to be solved by the invention]

The problem to be solved by the present invention is to eliminate the above-mentioned problems caused by glass materials that are blended to prevent the oxidation of carbon contained in fireproof materials, and to fully demonstrate the characteristics of the blended raw materials themselves. .

[Means to solve the problem]

The present invention has achieved the above object by coating a glass material added to prevent oxidation of carbon contained in a refractory with a resin having a high amount of fixed carbon.

In particular, by employing the injection granulation method as the coating means, elution of the glass material into moisture can be completely prevented.

The injection granulation method applied to the present invention is a conventionally known method in which the melt is poured onto a disk rotating at high speed, the liquid is shaken off by centrifugal force, and the liquid is atomized. The rotating disk type prevents solidification before spraying by heating the molten liquid and blowing hot air onto the rotating disk, or the rotating disk type that prevents solidification before spraying, or the molten liquid is pressurized and swirling force is applied in front of the small hole to spray out fine particles at high pressure. For granulation, any pressurized nozzle method in which the melt supply pipe or nozzle body is heated to the tip with a steam jacket, trace, or electric heater can be applied.

Further, as a glass material that can be applied to the present invention, phosphate glass is melted at a low temperature and coated with a non-oxide to suppress the reaction between carbon and oxygen.

In addition to soda glass, silicic acid glass, lead glass, etc., fine particles of silicon carbide and boron carbide have the property of reacting with oxygen to form low-melting glass and suppressing carbon oxidation. , silicon nitride, etc. are also included in the glass material of the present invention, and the particle size thereof is not particularly limited, but when considering the dispersibility when particles are added to the compound, it is 0.01 to 0.1.
Approximately mm is preferable.

In addition, the resin used for injection granulation in the present invention includes:
Any resin obtained by natural 9 synthesis can be used, but in order to more effectively prevent oxidation, resins with high fixed carbon content, such as pitch, phenol resin, and furan resin, are preferred. In order to increase the amount of fixed carbon in refractories, in addition to resins, we also use scaly graphite, globular graphite, artificial graphite, coke,
It is also possible to use a high softening point pitch or the like in combination.

The blending amount of the injection particles is preferably in the range of 1 to 20% by weight, although it depends on the non-oxide content in the refractory material.

Refractory materials to which the present invention can be applied include curls such as SiC, graphite, and coke: '(C), S! aN4. ZrB
a.

It is an alumina raw material containing a non-oxide raw material such as BN, and oxides such as MgO, ZrO2, and spinel can also be used as necessary.

In particular, when an alumina raw material is used as the refractory material, the optimum content thereof is 40 to 98% by weight, such as fused alumina, sintered alumina, sillimanite, and bauxite. If it is less than 40% by weight, the corrosion resistance of alumina cannot be exhibited, and if it is more than 98% by weight, the spalling resistance is poor, which is not preferable.

Further, the inclusion of a non-oxide as a refractory material is effective in terms of corrosion resistance and spalling resistance of the monolithic refractory, and the amount used is 2 to 60% by weight. If it is less than 2% by weight, the effect on corrosion resistance and volume stability will be weak, and
If it exceeds % by weight, workability deteriorates, leading to a significant increase in added moisture and decreasing tissue strength.

[Effect]

According to the present invention, the resin coating film on the glass material blended into the refractory is formed in a perfect state, thereby preventing exposure of the glass material during construction of the monolithic refractory containing non-oxides. Moreover, the thickness of the coating can be controlled arbitrarily.

In addition, since the amount of injection granules used in the formulation is such that a pulverization step is not required when adjusting the particle size, it is possible to do so only by classification.

Furthermore, the surface of the doped glass is no longer exposed,
Since elution from the glass can be prevented, there is no deterioration in workability during kneading, and it is possible to fully exhibit the effects of the blended glass material itself.

〔Example〕

Table 1 shows the characteristics of the particles used in the monolithic refractories of the present invention.

Particle size of 0.1u as glass material is added to heated and melted pitch.
The following borosilicate glass was mixed and granulated by the injection granulation method using a pressure nozzle type granulator, with an average particle size of 0.
3. Injection particles A of the present invention for carp.

Three types of particles, B and C, were obtained. Using these particles, we investigated the elution amount of glass components and the effect on the workability of alumina pouring material.

For comparison, similar tests were conducted on glass particles having no coating layer (Comparative Examples A to C) and a kneaded product with a kneader as a coating layer (Comparative Example D).

Referring to the table, if glass is used without surface coating,
Elution of glass components causes an increase in electrical conductivity (increase in workability-inhibiting ions), resulting in a decrease in fluidity.

This leads to shortening of curing time (unable to secure pot life).
A similar tendency was observed even when glass obtained by heating, kneading, and pulverization, which is a known method, was used.

On the other hand, by using the surface-treated glass according to the present invention, it has become possible to use a large amount of glass, even in the case of irregular shaped materials that use water, the workability of which deteriorates significantly due to elution of glass components.

Using the injection particle B according to the present invention shown in Table 1, Aj
The properties of 22o3 S+C pouring material were tested. The results are shown in Table 2.

For comparison, when no glass material is used (Comparative Example 1)
, Comparative Example A in Table 1 using an uncoated glass material (Comparative Example 2), and Comparative Example C in Table 1 using kneaded particles in the same manner (Comparative Example 3). ) were similarly tested and the results are also shown in Table 2.

As is clear from Table 2, according to the present invention, it is possible to use a large amount of glass material, which conventionally could not be used due to a large deterioration in workability, and it is possible to improve the acid resistance of the fireproof lining material. By improving the hardness and toughness in hot conditions, it has become possible to significantly improve crack resistance.

Table 3 shows the test results when the monolithic refractory of the present invention was subjected to an actual furnace test.

Altos-SiC-C pouring material (
Example 11) was applied to 350 as a repair material for the interior lining of a mixed pig iron car. As a comparative example, the same amount of Comparative Example 2 shown in Table 2 was mixed into the same pouring material and subjected to the same test.

As is clear from the same table, when the monolithic refractory of the present invention was used as a pouring material, the service life was three times longer than that of conventional repair materials.

Table 3 [Effects of the Invention] The monolithic refractory of the present invention can exhibit the following effects.

(1) Since the resin coating film on the glass material blended into the refractory is formed in a perfect state, there is no elution of the contained moisture, and the oxidation prevention function of the contained carbon can be fully exhibited. Therefore, a significant improvement in the hot toughness value and crack resistance of the constructed body was achieved.

(2) When adjusting the particle size, the particle size can be adjusted only by classification without the need for a pulverization process, which increases the efficiency of the refractory preparation process.

Claims (2)

[Claims] 1. A non-oxide-containing amorphous refractory material containing 1 to 20% by weight of particles of 0.5 mm or less obtained by injection granulation of a mixture of a resin melt with high fixed carbon content and glass powder. Refractory. 2. In the non-oxide-containing monolithic refractory according to claim 1, the non-oxidized refractory is obtained by adding 0.3 to 10% by weight of glass powder having a particle size of 0.01 to 1 mm in the granulation. Monolithic refractories containing solid materials.