JPS59471B2 - Monolithic refractory material for hot repair - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hot repair refractory material for hot repairing damaged parts of blast furnaces, pots, mixed iron furnaces, various smelting furnaces, other kilns, and the like.

Generally, when localized damage occurs on the charging side of the furnace during converter operation, a basic monolithic refractory is kneaded with Cool as a binder, packed in a plastic bag or paper bag, and then fixed on the charging side. It is used to burn the damaged area with the scorching effect of the lining.

Also, when replacing the runner bricks due to the hole enlargement of the tapping runner,
A similar basic amorphous refractory material is thrown onto the eroded groove formed between the recently replaced new runner brick and the old surrounding brick and its vicinity, and the groove is filled and baked.

For this reason, the refractory material is required to have properties suitable for the area to be repaired, such as fluidity, viscosity, sinterability, corrosion resistance, and abrasion resistance.

For example, when repairing the grooves between bricks when replacing the runner bricks mentioned above, fluidity and sinterability must be adjusted in particular so that the material can quickly penetrate into deep grooves and seize.

This fluidity and sinterability are imparted particularly by tar or pitch added as a binder.

However, when using tar or pitch (1) Although tar and pitch have been used by adjusting their softening point, concentration, particle size, etc., they have not been fully satisfactory.

(2) Since tar and the like are used, there is environmental pollution due to smoke, gas generation, and bad odor, as well as skin damage, which is not good for hygiene.

(3) Due to the hardening of the tar, there were defects in the shelf life and manufacturing aspects of the product.

The present invention was developed in order to eliminate the above-mentioned drawbacks of refractory materials for hot repair.

However, the term "powder pitch" here refers to powdered coal-based pitch, and the "petroleum-based reformed product" refers to a solid powder that is polycondensed in a cracking furnace at high temperatures for a short period of time using crude oil as a raw material. Fixed carbon: 30% or more, preferably 60% or more, benzol insoluble content: 10% or more, preferably 50% or more, Ki/IJ
The insoluble content is 2% or more, preferably 10% or more.

As the base material of the refractory material of the present invention, any base material suitable for the purpose of the furnace in which the refractory material is to be used is used.

For example, in the case of a metal smelting furnace, a basic refractory material such as magnesia or maguro is selected, and the base material in each case is purchased, and the additive of the present invention to be added to the base material is determined in the amount of the base material. Unless otherwise specified, 100 parts by weight or parts by weight are expressed as % by weight or parts by weight (unless otherwise specified).

The powdered pitch and petroleum modified product to be used are as described above, but when hot strength, early strength, and corrosion resistance are required, those containing a large amount of fixed carbon are preferred.

Dihydric alcohols are used herein to include dihydric alcohols and their polymers, and those belonging to these include polyethylene glycol, polypropylene glycol, diethylene glycol, dipropylene glycol, monoethylene glycol, and monopropylene glycol. Polyethylene and Glyfur are widely used with molecular weights ranging from 200 to 6,000;
Those having a molecular weight in the range of 0 to 400 are liquid and most suitable for this purpose, but those having a larger molecular weight can also be used as long as they exhibit a liquid state at 40 to 60°C.

Particularly in the case of polyethylene glycol, it has lipophilic groups and hydrophilic groups and also has a surface-activating effect, so that it can achieve the purpose of being a pre-caking product.

In the present invention, polybutene is used as having the same purpose as dihydric alcohol or its polymer, but
The polybutene that can be used in the present invention has an average molecular weight of 350 to 2.
650 can be used, and those used in the tests of the present invention are, for example, average molecular weight 940, viscosity S
The one with an average molecular weight of 400 and the viscosity of SSU 210F42 has an average molecular weight of 940.
Of course, polybutenes in other ranges can also be used.

Generally, the higher the molecular weight, the higher the viscosity, and the lower the molecular weight, the lower the viscosity. Therefore, the type and amount thereof are adjusted within the range of the blending ratio of the present invention.

The purpose of using dihydric alcohols, their polymers, and polybutenes is to provide the necessary fluidity to quickly and effectively fill damaged deep grooves and depressions on the inner wall of the furnace, as well as to provide instantaneous baking. be used for the purpose of

Next, the reason for limiting the blending ratio of these additives will be explained based on experimental results.

In this experiment, polybutene with an average molecular weight of 940 was used, and polyethylene glycol with an average molecular weight of 600 was used.

As shown in the above experimental results, by adding either powdered pitch or petroleum modification to the refractory material,
Provides corrosion resistance and hot strength, and functions as a binding material.

If the amount added is less than 3%, there is no effect, and if it is 20%, the structure becomes coarse and brittle, resulting in poor corrosion resistance and wear resistance, as well as severe smoke and bad odor.

If the amount of dihydric alcohol or its polymer or polybutene added is less than 3%, it will not be effective, and if it exceeds 20%, the structure will become brittle, the viscosity will be too insufficient, the structure will become porous, and the seizure will be too high. If this is done quickly and instantaneously, the filling performance will be impaired.

However, the amount of these compounds needs to be adjusted depending on the type of dihydric alcohol used. For example, in the case of ethylene glycol, the viscosity is insufficient, so the above-mentioned polybutene having an average molecular weight of 940 is added to compensate for this.

In this case, the ratio of ethylene glycol to polybutene is preferably in the range of 70:30 to 85:15, but the total amount is added within the range of 3 to 20%.

In addition to the above, sodium phosphate is added as an additive, and the purpose of adding sodium phosphate is as follows: (1) Since the repair material comes into immediate contact with molten steel, it is added because it is necessary to provide initial seizure strength.

(2) It is also necessary to impart strength and wear resistance in the intermediate temperature range (500 to 800°C).

(3) It is also necessary to appropriately suppress the oxidation of other combustible dihydric alcohols, polybutene, and powder pitch in order to achieve a more preferable baking state.

The amount of sodium phosphate added to exhibit these functions is 1 to 5%, thereby exhibiting desirable characteristics as a hot repair material.

However, if it is less than 1%, there is no effect, and if it is more than 5%, the effect of the combination is lost and sinterability, strength, filling properties, and fluidity are impaired, resulting in an unfavorable result.

In this way, sodium phosphate can also be used for the purpose of controlling the amount of the polybutene, dihydric alcohol, or polymer thereof added by adjusting the amount added.

As described above, the refractory material for hot repair of the present invention combines powdered pitch or petroleum reformer, dihydric alcohol or its polymer, and polybutene in a range of 3 to 20%, and sodium phosphate in a range of 1 to 5%. By combining within the range of , it is now possible to use repair refractories that match the types and conditions of various furnaces.

Note that different properties are required depending on the location of repair even within the same furnace, so the combination and amount of addition should be selected to suit the purpose.

It should be noted that the repair material of the present invention can be packaged and thrown, or used with a projector, an injection machine, a press-in machine, an inflow machine, etc. in the same way as a normal repair material.

In addition to adjusting the above combinations and amounts of the present invention, the fluidity, viscosity, fillability, sinterability, strength, corrosion resistance, abrasion resistance, etc. of the refractory material for repair can be adjusted appropriately. Manufacturing conditions have been greatly improved, smoke generation has been reduced to 1/10 of the conventional level, there is no bad odor, the work environment has been improved, and repair time has been shortened to 1/2, resulting in lighter labor. Ta.

In addition, the refractory material for hot repair of the present invention did not undergo any reaction hardening between the materials, had good storage stability, and exhibited almost no change in performance even after long-term storage.

Example 1 Particle size as base material: 3.36 to 50%, 1 mm or less 25
% of magnesia clinker and 25% of magnesia powder.
The charging side of the converter using the refractory material for hot repair with the composition of -2,
It was used for repair by throwing it at the damaged part (1300°C to 1500°C) of the tap hole.

As a result, the generation of black smoke was extremely low, the working time was shortened, and the corrosion resistance was improved.

Claims (1)

[Claims] 1 3 to 20 parts by weight of powdered pitch or petroleum-based modified material and 70:30 to 85 parts of dihydric alcohol or its polymer and polybutene to 100 parts by weight of the personnel-resistant base material.
1. A monolithic refractory material for hot repair characterized by comprising 3 to 20 parts by weight of sodium phosphate in combination at a ratio of 15 to 20 parts by weight, and 1 to 5 parts by weight of sodium phosphate.