KR0144771B1 - Refractory composition for sealing - Google Patents

Abstract

The present invention relates to an indefinite refractory to hot repair for the partially damaged portion of the bottom or charging wall, tapping wall of various steelmaking furnaces such as converter, etc. It is manufactured by adding and mixing the appropriate amount, and it is easier to manufacture than the conventional one, and it does not occur hardening due to sedimentation and vibration by vibration when storing and transporting. The present invention relates to an amorphous refractory composition for hot repair, which can be hardened and adhered to excellent solvent resistance, and can reduce the generation of smoke and shorten the combustion time, thereby achieving a remarkable effect of smooth operation and extending the life of a furnace.

Description

Hot Repair Indeterminate Refractory Composition

The present invention relates to an indefinite refractory composition used for hot repair for the repair and smooth operation of partially damaged parts of floors, charging walls and tapping walls of various steel making furnaces such as converters and for extending the life of the furnace.

Various hot-injection and repair materials are widely used for repairing floors, charging walls, and partially damaged areas of steelworks such as converters, and for smooth operation and long service life of the furnace.

Refractory materials as these materials are prepared by adding and kneading tar, pitch, or the like, or by using a phosphate binder containing moisture or the like, or by adding a phenol resin to form a solid, powder or slurry or skin. In some cases, it may be put into maintenance surfaces such as converters and burned using a royal furnace to be attached and used.

Conventional tar and pitch-based refractory materials have good fluidity between the hot and carbon bonds at high temperatures, and exhibit excellent usability.However, the high pitch and tar content results in a long burning time and a high generation rate. In addition to causing pollution problems, there is a difficulty in dissolving and packaging tar during manufacturing, and in particular, a repair time, that is, a time for repairing flow, adhesion, and damaged parts by adding a repair material, has a disadvantage of preventing improvement in converter operation rate. There is a problem.

In addition, in the case of a hot input water-retaining material in which water-containing phosphate-based binder is added as a refractory material, it is possible to give fluidity by adjusting the amount of water after a short time before the water-retaining material is boiled and then attached. Inferior to the pitch system in terms of hot strength and adhesiveness and is expensive.

Moreover, hot input repair materials made by adding phenolic resins to reduce soot and shorten burning time are also expensive, and have problems such as low fluidity, long-term change, and long burning time. See 126679 and Japanese Patent Laid-Open No. Hei 3-271168.)

Recently, in order to reduce soot and combustion time as a non-aqueous system and to improve hot strength and adhesiveness, a repair material added by using a pitch and a phenol resin was developed. However, the problem of poor fluidity and the shrinkage of phenol resin It is known that there are problems of poor adhesion, burn time, separation of layers due to manufacturing transport, and the like (Japanese Patent Laid-Open No. 62-110473, 平 4-310578).

The characteristics to be provided as hot input repairing materials should be easy to manufacture, and during storage and transportation, the sedimentation or layer separation due to vibration does not occur. In order to reduce soot generation and shorten the combustion period, a hot input repair material using a phenolic resin binder is generally used, but it is hard to repair damaged repaired surface due to insufficient flow due to hardening before softening after input at high temperature.

Therefore, in order to solve such a problem, a soluble organic solvent having a flash point equal to or slightly higher than the softening point of the powdery pitch is added to the liquid novolak-type resin, and a dispersant is blended to provide a long shelf life, sufficient fluidity, and adhesion. It is an object of the present invention to obtain an excellent construction body.

The present invention adds a dispersant to 15 to 20% by weight of the powdery pitch and the liquid novolac phenolic resin based on 70 to 80% by weight of the fire resistant aggregate, and the flash point of the soluble organic solvent is about 0 to 50 ° C than the softening point of the powdery pitch. It is made into the hot repair irregularity refractory material made by adding and mix | blending 5-10 weight% of liquid resin which made it high and is 8-12 poise which can be kneaded at normal temperature.

Refractory materials used in molten metal containers such as converters have recently been used by adding carbon materials to refractory aggregates. When carbon material is added, the quality is improved by absorbing heat-shrinkage shrinkage of refractory at high temperature and improving corrosion resistance due to impermeability of the molten metal layer, so that the carbon source of the hot refilling material has good fluidity, high residual carbon ratio, and relatively low price. Pitch and tar are widely used. However, pitches contain harmful substances in the volatile gas and cause environmental problems due to severe soot during hot repair. Recently, instead of reducing the amount of pitch, they are used together with phenol resins to solve this problem.

The pitch used for the hot repair amorphous refractory material according to the present invention is a solid petroleum pitch or a coal tar pitch, preferably having a softening point of 70 to 130 ° C, and preferably having a particle size of 1 mm or less. The pitch softens and flows through the Royal, and then burns, adheres, and carbonizes to form carbon bonds. However, if the softening point is less than 70 ° C, the residual carbon content is not only low, but there is a problem in storage after manufacture. Long burning time The amount of pitch added is preferably 15 to 20% by weight relative to 100% by weight of the fire resistant aggregate in view of flow and soot generation.

As the phenol resin added to the refractory material, it is preferable that the number average molecular weight is 300 to 1000 as a liquid phase. Liquid resin prevents dust during manufacture and use and is convenient for packaging and transportation. This liquid resin has a low melting point when the number average molecular weight is 300 or less, and becomes a solid, partially porous structure. When the liquid resin exceeds 1000, the thermal softening property is deteriorated, and thermal expansion shrinkage during the carbonization process causes peeling. Moreover, as this liquid phenol resin, a novolak-type resin is preferable. It dissolves and absorbs heat when it comes into contact with high temperature parts, and the heat absorbed area is cooled by this heat absorption, so that the addition of the soluble organic solvent added to the liquid novolak-type phenolic resin which is effectively bonded makes room temperature training possible. Eliminates time dust and increases fluidity, especially during use. However, this organic solvent should have a flash point equal to the softening point of the powdery pitch used or as high as 50 ° C. Otherwise, it will volatilize before the powdery pitch, leading to poor hot flow of the product. In the case of hot input repair material, it fills and repairs the damaged concave by flowing in hot. However, when the flash point of the organic solvent is lower than the softening point of the pitch, the phenol resin hardens first and prevents the flow of the pitch, making repair of the damaged part difficult and causing peeling. However, when the flash point of the organic solvent is 50 ° C. or more higher than the softening point of the powdery pitch used, the fluidity is good, but the combustion time is long, and the repair time is long. As such soluble organic solvent, alcohol soluble organic solvent is preferable.

Furthermore, a dispersant should be added to the liquid novolak type panol resin. Otherwise, during storage and transportation, the resin, together with the aggregate, will settle, solidify, and reduce hot fluidity, making smooth repair impossible. This dispersant may be either an organic or an inorganic dispersant, but in particular, it should be a dispersant which prevents changes over time by hydration with dolomite aggregate. As such a dispersant, a silicone oil dispersant is preferable.

It is preferable to add an organic solvent and a dispersing agent so that the viscosity of a liquid novolak-type phenol resin may be 8-12 poise. This is because the amount of fixed carbon decreases at less than 8 poises, resulting in deterioration of quality.

As the magnesia grains used in the hot repair amorphous refractory according to the present invention, seawater magnesia clinker, molten magnesia clinker, natural magnesia clinker, etc. are used as raw materials for general production, and as a dolomite grain, natural dolomite clinker, synthetic dolomite clean It is used as a raw material for manufacturing Kerr. It is used as a mixture of magnesia grains alone or with dolomite grains depending on the purpose.

As shown in Table 1, [Comparative Example] shows a longer burning time than the case of [Examples 1 and 2] in the burning time, and the adhesive strength and the compressive strength also showed excellent results.

As a result of comparing the three types of hot input and repair materials shown in Table 1 to the converter charging wall, which is steelmaking furnace, 1 ton each, the fireproof composition according to the present invention was superior to the comparative products in terms of fluidity and usability. The effect was confirmed.

In the following, [Examples] and [Comparative Examples] of the present invention are described in detail.

EXAMPLE

As shown in Table 1, samples of the developed product were prepared and placed in 250 x 250 mm MgO C-quality bricks of a small kerosene furnace kept at 500 ° C. at 1200 ° C. to measure spreading diameters and combustion periods due to flow. Also, make a hole of 50 Ø in 80 X 80 X 150mm MgO-C brick, keep it at 1200 ℃ for 1 hour in an electric furnace, take it out, inject 250g of sample, burn it, and measure the sticking strength and compressive strength. Apparent porosity and volume specific gravity were measured.

[Comparative Example]

500 g of the comparative product sample of the hot preparation shown in Table 1 was put on a 250 × 250 mm MgO C-quality brick plate of a small kerosene furnace maintained at 1200 ° C. to measure the spreading diameter and the combustion time due to flow. In addition, the adhesive strength, the compressive strength, the apparent porosity, and the volume specific gravity were measured in the same manner as in [Example].

* S.P: Softening Point (℃) ** Content is expressed in weight percent

F.P: Flash Point (℃)

Claims (5)

5 to 10% by weight of liquid novolac phenolic resins having a viscosity of 15 to 20% by weight in powder form and kneading at room temperature with respect to 70 to 80% by weight of magnesia granules or a mixture of magnesia granules and dolomite granules. Hot repairing amorphous fire-resistant composition made by adding to 100% by weight. The alcohol-soluble organic solvent according to claim 1, wherein the liquid novolak-type phenolic resin has a flash point equal to the softening point of the powdery pitch or a high range up to 50 ° C so as to be a liquid resin having a viscosity of 8 to 12 poise, which can be kneaded in an aon. Hot repairing amorphous fireproof composition, characterized in that the addition. 2. The amorphous refractory composition for hot repair of claim 1, wherein the pitch is a solid petroleum pitch or a coal tar pitch, having a softening point of 70 to 130 ° C, and a particle of 1 mm or less. 2. The amorphous refractory composition for hot repair according to claim 1, wherein the liquid novolak type phenol resin has a number average molecular weight of 300 to 1000. 2. The amorphous refractory composition for hot repair of claim 1, wherein a silicone oil dispersant is added to the liquid novolac phenolic resin to prevent the resin from settling with the aggregate when the temperature and pressure range are changed.