JPH04170369A - Spray repair material and spray repair method - Google Patents

Abstract

PURPOSE:To obtain the spray repair material capable of enhancing-the adhesive properties on a furnace wall and of increasing the durable frequency by blending an organic binder and a phosphoric acid based binder with refractory material. CONSTITUTION:The spray repair material is obtained by incorporating 3-20 pts.wt. organic binder and 0.5-5 pts.wt. phosphoric acid-based binder into 100 pts.wt. refractory material. The used refractory material is selected in coincidence with the material of a vessel for the applied molten metal. Further the organic binder is polymerized at high temp. and forms a carbon bond. A carbon resin such as pitch and tar or a resin such as phenolic resin and melamine resin is used. In order to use the organic resin especially in a wide range to a warm time from a hot time, pitch and phenolic resin are preferably used in combination. As a spray machine for spraying the spray repair material, a dry spraying machine of a nozzle mixing system is intactly used which mixes the material with the most generally and presently used water.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a spray repair material and a spray repair method for molten metal containers for pig iron making and steel making, and more specifically, the present invention relates to a spray repair material and a spray repair method for molten metal containers for iron making and steel making. This invention relates to a spraying repair material and a spraying repair method that can be sprayed for repair.

[Prior Art] Dry spraying repair methods have been generally employed for repairing molten metal containers for pig iron and steel production, such as converters, pig iron mixers, ladles, and tundishes. In this method, the spraying material is pneumatically fed from a hopper to the spraying machine, and the spraying material and water are mixed at the tip of the spraying machine to form a slurry, which is sprayed onto the repaired area and adheres to it. The amount of moisture used at this time is 10 to 40 parts by weight per 100 parts by weight of the spraying material, depending on the temperature of the repaired wall surface. The binder used in this sprayed material is generally a silicic acid-based or a phosphoric acid-based binder since water is used.

In addition, with the recent adoption of carbon-containing bricks, spraying materials now contain carbonaceous materials, and spraying methods that use organic resins as binders and do not use water have also been seen (Japanese Patent Application Laid-Open No.
4-125105).

[Problem to be solved by the invention] When using an inorganic binder in hot spray repair where the temperature of the repaired wall surface is high, it is necessary to cool the wall surface in order to increase the adhesion rate of the material. I have to spray it. High moisture content results in a repaired body with high porosity and requires the use of a large amount of binder, resulting in reduced durability.

Furthermore, there is a drawback that when high moisture is sprayed onto a vertical wall surface, a large amount of material flows down. Conversely, if the water content is reduced, the rebound loss of the material will increase.

When non-aqueous spraying materials do not use water, pitch or phenolic resin is used as a binder, so hot spraying produces smoke due to combustion of the binder, which poses environmental problems and is not suitable for visual spraying. There is a problem that makes it difficult to understand. Additionally, when using water, the spray water can also be used to cool and protect the nozzle of the spray machine, but for spray repairs that do not use water, cooling of the spray machine nozzle must be considered separately.

[Means for Solving the Problems] The present inventors have overcome the above-mentioned problems and have conducted various studies on spray repair materials and spray repair methods that can handle the temperature of the repaired wall surface from hot to cold, and have developed the present invention. The gist of the present invention is to provide a spray repair material containing 3 to 20 parts by weight of an organic binder and 0.5 to 5 parts by weight of a phosphoric acid binder per 100 parts by weight of a fireproof material; This is a spray repair method characterized in that the spray repair material is sprayed using a normal nozzle mix type dry spray machine, with water added in an amount of 5 to 20 parts by weight per 100 parts by weight of the fireproof material.

The fireproof material used in the hot spray repair material of the present invention is selected depending on the material of the molten metal container to which it is applied. In other words, acidic or neutral oxide refractory materials such as alumina, silica/alumina, spinel, zircon, and zirconia are used for repairing pig iron mixers and hot metal ladle, while for repairing converters, molten steel ladle, and tandates, etc. One or more basic or neutral refractory materials such as magnesia, alumina, and spinel are used. In addition, non-oxide refractory materials such as silicon carbide and silicon nitride, and carbonaceous materials such as graphite can also be added as appropriate.

The particle size of the refractory material used may be within the particle size range of ordinary spray repair materials.

The organic binder is one that polymerizes at high temperatures to form carbon bonds, and carbon resins such as pitch and tar, or resins such as phenol resins, melamine resins, and urea resins are used alone or in combination.

The organic resin may be in powder or liquid form, and an appropriate solvent may be used in combination. In particular, for use over a wide range from hot to warm temperatures, it is preferable to use pitch and phenol resin in combination. The combined use of pitch and phenolic resin is advantageous because it prevents the material from flowing down at high temperatures when pitch alone is used.

The amount of organic binder used is 3 parts by weight per 100 parts by weight of the fireproof material.
~20 parts by weight. If the amount used is less than 3 parts by weight, sufficient carbon bonds will not be formed, and if it is more than 20 parts by weight, a dense construction product cannot be obtained. There is a close relationship between the usage amount and furnace wall temperature, and the higher the furnace wall temperature, the larger the usage amount. The standard is 13 parts by weight or more at 1000℃ or higher, 800 to 1000
10 to 14 parts by weight at °C, 12 parts by weight at temperatures below 800 °C
Parts by weight or less. When pitch and phenolic resin are used together, the phenol resin is 13 to 15 parts by weight, the pitch is 0 to 12 parts by weight, and the content of both is 3 to 20 parts by weight.
Preferably, the content of the phenol resin is 4 to 15 parts by weight, the pitch is 1 to 10 parts by weight, and the content of both is 5 to 18 parts by weight.

A feature of the present invention is that a phosphoric acid binder is used in combination with an organic binder as a binder. As the phosphoric acid binder, various phosphoric acids, condensed phosphoric acids, and their alkali metal salts, alkaline earth metal salts, aluminum salts, etc. can be used. In the case of acidic or neutral refractory materials, it is necessary to use a curing agent for the phosphoric acid binder.

This phosphoric acid binder improves the initial adhesion of the spraying material to the repaired wall surface and gives the construction body initial shape retention, but the curing speed of the phosphoric acid binder when water is added is Speed (
It has been found that, when present in large amounts, it inhibits the subsequent reaction of forming carbon bonds through polymerization of the organic binder.

However, it was also found that if the amount of phosphoric acid-based binder used is small, it does not significantly affect the formation of carbon bonds.

Therefore, it is desirable to use the phosphoric acid binder in an amount that does not reduce the carbon bond formation reaction.

The amount of the phosphoric acid binder used is 0.5 to 5 parts by weight, preferably 0.5 to 3 parts by weight, per 100 parts by weight of the refractory material. Since the phosphoric acid binder is used to assist in adhesion by the organic binder, the lower the furnace wall temperature, the more it is used. As a guideline, the furnace wall temperature is 1000
03 to 2 parts by weight above ℃, aoo to 1ooo ℃Te0
．． 7 to 3 parts by weight, and 2 to 4 parts by weight below 800'C. If it is used in an amount of 5 parts by weight or more, the formation of carbon bonds in the organic binder will be inhibited, and if it is less than 0.5 parts by weight, the adhesion rate will decrease due to an increase in rebound loss.

In addition to the above-mentioned components, the spray repair material of the present invention contains various fibrous materials for the purpose of preventing peeling of the construction body, and metal powder to improve the strength of the construction body and prevent oxidation of carbon bonds. Of course, other additives used in ordinary spray materials can also be used.

Next, the spray repair method of the present invention will be described.

The present invention is characterized in that the spraying machine can be a dry spraying machine of a nozzle mix type, which mixes water and material using a nozzle, which is currently in general use.

The amount of water added is determined by the type of refractory material, type of bonding material, and temperature of the repaired wall. Moisture is added for the purpose of cooling the nozzle with water, preventing the organic binder from burning due to furnace heat and emitting smoke, and assisting the carbon bonding reaction of the organic binder. In other words, organic binders are softened by heat and then hardened by a polymerization reaction, but this hardening rate changes at a temperature of 1ε and is slow compared to the hardening rate of inorganic binders. The aim is to compensate for the formation of carbon bonds from organic binders by curing the binder. Therefore, the amount of phosphoric acid binder and water added can basically be reduced as the temperature increases and the carbon bond formation reaction of the organic binder becomes faster. Since it also has the role of , a certain amount or more is required. The amount is 5 to 20 parts by weight per 100 parts by weight of the refractory material.

[Function] As is clear from the above explanation, in the spray repair material of the present invention, by using a combination of an organic binder and a phosphoric acid binder, and by using the organic binder in a range of 3 to 20% by weight. in,
In a wide temperature range of the furnace wall to be repaired, sufficient carbon bonding is generated to form a dense construction body, and the phosphoric acid binder is contained within a range of 0.5 to 5% by weight, which is less than that of ordinary blown aggregate. It is used to improve the initial adhesion of the sprayed material to the wall surface to be repaired and to improve the shape retention of the construction body without inhibiting the formation of carbon bonds by the organic binder.

This product can be applied using a nozzle mix type dry spraying machine and can be applied in a low moisture range of 5 to 20%, so it provides the excellent effects described below during spraying.

The water introduced into the nozzle is mixed with the material pneumatically fed from the hopper to form a slurry, and a portion of the water evaporates inside the nozzle to cool the nozzle. During the subsequent injection, water is involved, so even if an organic binder is used, a film of water is formed and no smoke is emitted.Furthermore, the phosphoric acid binder in the slurry material hardens due to the action of water. As the process begins, the organic binder reaches the repaired wall surface while being partially softened. The material that reaches the repaired wall surface quickly adheres to the wall surface due to the curing of the phosphoric acid-based binder, which begins to harden due to the action of water during injection, and the hardening of the organic binder, with little rebound loss.

In addition, since most of the water has evaporated, the bonds of phosphates do not develop after that, and the polymerization of the organic binder due to the temperature rise of the material is not inhibited, so the refractory material becomes a strong construction body due to carbon bonds. Become.

In this way, in the present invention, water acts to cool the spray nozzle, transport the material, prevent the organic binder from producing smoke, and initiate the reaction of the phosphoric acid binder.

It combines the advantages of dry spraying and wet spraying.

[Example] Examples 1 to 5, Comparative Examples 1 to 7 500k of the material shown in Table 1 was applied to the trunnion part of the belly of the converter.
g was repaired by spraying using a nozzle mix type dry spraying machine. The construction results and usage results are also shown in the same table.

Examples 6-7, Comparative Examples 8-9 200 kg of the materials shown in Table 1 were similarly sprayed onto the side walls of the ladle.

The formulations and added water in Table 1 are expressed in parts by weight. The adhesion rate was determined by visual inspection, and the service life was determined by the number of times the converter was used to tap the steel or the ladle received the steel until the sprayed body had no residual material.

Comparative Example 1 is a typical example in which the high-temperature furnace wall of a converter was sprayed and repaired using a conventional phosphoric acid binder. By using a phosphoric acid binder in combination, the amount of phosphoric acid binder and added water can be reduced (
By doing so, the adhesion rate does not decrease and the durability increases. This suggests that a dense construction body is formed.

Further, even if the added water content was reduced, no smoke generation or adverse effects on the spray machine were observed. Furthermore, it can be seen that by adjusting the phosphoric acid binder, organic binder, and added moisture, it can be applied to a wide temperature range from hot to warm (Examples 1 to 3).
4). On the other hand, when only an organic binder is used, almost no adhesion occurs (Comparative Example 3), when a large amount of water is added (Comparative Example 6), and when a large amount of phosphoric acid binder is used (Comparative Example 2.4).
), it can also be seen that durability decreases.

Similar results were seen for ladle spray repair.

[Effects of the invention] The characteristics of the present invention, which uses an organic binder and a phosphoric acid binder together, and also uses a small amount of phosphoric acid binder and added water, are the same as the adhesion to the furnace wall and the durability. Another great advantage is that conventional spraying machines and spraying methods can be used as they are.

Claims (2)

[Claims] (1) 3 to 2 parts of organic binder per 100 parts by weight of fireproof material
A spray repair material characterized by containing 0 parts by weight and 0.5 to 5 parts by weight of a phosphoric acid binder. (2) 3 to 2 parts of organic binder per 100 parts by weight of fireproof material
Using a nozzle mix type dry spraying machine, spray repair material containing 0 parts by weight and 0.5 to 5 parts by weight of a phosphoric acid binder,
A spraying repair method characterized by adding 5 to 20 parts by weight of water to 100 parts by weight of a fireproof material and spraying the mixture.