JPS5819631B2 - Self-hardening fireproof composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a self-hardening refractory composition that can be used as a lining material, filler, or repair material for blast furnaces, converters, and other types of pig iron, steel-making furnaces, and tap troughs.

Conventionally, phosphoric acid binder compositions have been used as self-hardening fireproof compositions,
Water glass binder compositions and alumina cement binder compositions are known, but each has its own problems.

That is, in a phosphoric acid binder composition, a reaction occurs between phosphoric acid and the refractory aggregate or impurity components in the refractory aggregate, making it difficult to control the curing time at a constant level.

In addition, there are problems such as migration during drying (the binder moves to the surface, which tends to make the structure non-uniform, and when used in a high-temperature reducing atmosphere, bonding deteriorates, resulting in poor durability).

Water glass binder compositions are also easily affected by curing agents and temperature, making it difficult to maintain a constant curing time, easily causing migration during drying, and having low hot strength and slag resistance, and under harsh conditions. It has problems such as being difficult to use because it is easily eroded.

Alumina cement binder compositions are easily affected by temperature, and it is difficult to control the curing time at a constant level.

In addition, curing requires a long period of time, and if the drying speed is too fast, the crystallized water generated by the water-use reaction during curing will suddenly generate water vapor and easily explode, and even if drying is done properly, the crystallized water will There was shrinkage and strength deterioration due to dehydration, and 100%
There are problems such as significant strength deterioration at around 0°C.

Carbon bonds are known as bonds that are strong against hot metal and molten steel slag, and with this in mind, the present invention has focused on a binder with a large amount of fixed carbon and a hardening agent that has a stable hardening effect on the binder at room temperature. went.

That is, it is known that binders having a methylol group in the molecule, such as resol type phenolic resins or furan resins, can be acid-cured at room temperature, and p-toluenesulfonic acid, oxalic acid, sulfuric acid, hydrochloric acid, and nitric acid can be used as curing agents. , phosphoric acid and other acids are used.

Depending on the purpose of use, both resol-type phenolic resins and furan resins are modified to be alcoholic or water-soluble, and are often used with a diluent such as water to adjust the viscosity, and inorganic acids are often used. In this case, curing is fast and accompanied by a rapid exothermic reaction, and it is difficult to adjust the curing time to a constant level.Also, resins such as resol type phenolic resins and furan resins are selectively cured, and the diluent is liberated. As a result, the structure of the cured product tends to become non-uniform, which poses a problem in its durability as a refractory.

When organic acids such as para-toluenesulfonic acid and oxalic acid are used, the curing time is slow, and when pouring is used, it takes a long time to remove the frame, and when used as a repair material for furnace walls, it takes a long time.

Although it is possible to speed up the curing time by increasing the amount of curing agent, the porosity of the cured refractory composition increases after heating and the structural strength also decreases, which poses a problem in durability.

In consideration of the above, the present invention uses a resol type phenolic resin and a furan resin as a binder in the refractory aggregate, and uses a mixed acid of an organic sulfonic acid and an inorganic acid including sulfuric acid as a hardening agent. This is a self-hardening refractory composition that eliminates the drawbacks.

That is, the self-hardening fireproofing composition of the present invention has a quick curing time, can obtain a uniform structure of the cured product, has little reaction heat accompanying curing, has little variation in curing time, and can be cured at any desired curing time. can get.

After firing, the cured composition of the present invention has a uniform structure, high strength, excellent corrosion resistance, and improved oxidation resistance.

Although the weakness of carbon bonds is that it is difficult to use in an oxidizing atmosphere, the refractory composition of the present invention has characteristics such as durability even in an oxidizing atmosphere.

The present invention will be explained in detail below.

As the refractory aggregate used in the present invention, alumina, silica, magnesia, silicon carbide, carbon, etc., which are usually used for refractories, can be selected as appropriate depending on the location and purpose.

For example, 5i is used as a pouring filler between blast furnace shells and bricks.
The main component is C-C type structural strength aggregate, and as a pouring material or repair material for the blast furnace wall, high-temperature alumina containing mainly fused alumina and sintered alumina is used for the morning glory section, the furnace abdomen, and the lower part of the shaft, where the internal temperature is high. Alumina materials are used, and alumina chamotte and waxite materials are used in the middle of the shaft where the temperature is slightly lower.

Also, as the joint material for MgC)-C bricks, a material mainly composed of magnesia or carbon is used, and as the joint material for A1203-C bricks, a material mainly composed of alumina or carbon is used.

Since the self-hardening refractory composition of the present invention is obtained by acid curing, when SiC, which contains many impurities and is highly reactive, and basic magnesia and dolomite are used as refractory aggregates, it is necessary to The reaction may precede the curing reaction of the binder, generating bubbles and creating a porous structure.
Preferably, for these refractory aggregates, the pitch,
It is desirable to coat the surface with vinyl acetate resin liquid or the like.

Depending on the purpose of use, the resol type phenolic resin used in the present invention is a phenol resin alone or a mixed solution with alcohol, a water-soluble phenol resin is a mixed solution with water, and an oil-soluble phenol resin is a mixed solution with oil. It is used in such situations.

As the furan resin, furfuryl alcohol resin, furfural-furfuryl alcohol resin, furfural-phenol resin, furfuryl alcohol-phenol resin, etc. are used, and if necessary, the resin is used after adjusting the viscosity with alcohols or ethers. .

When used as a binder, resol type phenolic resin.

Furan resins can be used alone or in combination, and when used in combination, the mixing ratio can be arbitrarily selected depending on the purpose.

If alkali resistance is required, the mixing ratio of resol type phenolic resin and furan resin is 10:90 to 50:50.
used within the range.

When the ratio is 10:90 or less, the alkali resistance is good, but it is not possible to prevent damage caused by thermal expansion of the furan resin;
If it is 50 or more, the alkali resistance is poor.

On the other hand, if alkali resistance is not required, 30 nia 0 to 70
A mixing ratio of :30 is desirable because of good volume stability.

The curing agent used in the present invention is an organic sulfonic acid such as
Aliphatic sulfonic acids and aromatic sulfonic acids are used,
Preferably benzenesulfonic acid, toluenesulfonic acid,
Aromatic sulfonic acids such as xylene sulfonic acid and naphthalene sulfonic acid are preferred.

As the inorganic acids, sulfuric acid, nitric acid, hydrochloric acid, phosphoric acid, and boric acid may be used, but one or more inorganic mixed acids including sulfuric acid are preferred.

The mixed weight ratio of the inorganic mixed acids is preferably less than 50% by weight for sulfuric acid and 50% by weight or more for phosphoric acid and/or boric acid.

Sulfuric acid acts to stabilize the aromatic sulfonic acid in the curing agent and accelerate the curing speed.

In addition, phosphoric acid and boric acid have the effect of accelerating the curing speed and improving the oxidation resistance of carbon bonds generated by heating.

The mixing ratio by weight of organic sulfonic acid and inorganic mixed acid in the curing agent of the present invention is used in the range of 90:10 to 10:90.

When the ratio is 90:10 or less, a uniform composition can be obtained, but the curing rate is slow, so it is necessary to increase the amount of curing agent for fast curing, and as a result, the pores of the cured composition after firing are reduced. The rate is high, the speed is low, the oxidation resistance is poor, and the durability is insufficient.

If the ratio is more than 10:90, the resin component will be selectively cured, making it impossible to obtain a uniform structure, and curing will be too rapid, making it difficult to adjust the curing time by changing the amount of curing agent.

The amount of curing agent per 100 parts by weight of the resin in the binder is usually preferably 5 to 40 parts by weight, and is adjusted depending on the required curing time.

When the amount is less than 5 parts by weight, curing is slow and requires 24 hours or more, and the resulting cured product becomes a gel-like product, making it impossible to obtain sufficient strength.

If the amount is 40 parts by weight or more, the curing may be rapid and it may be difficult to secure the necessary working time.

The composition of the present invention is usually obtained by adding appropriate amounts of a binder and a curing agent depending on the purpose of use to 100 parts by weight of refractory aggregate immediately before construction.

For example, in the case of pouring construction, it is usually obtained by adding and kneading 5 to 30 parts by weight, although this varies depending on the type of aggregate.

If it is less than 5 parts by weight, the fluidity necessary for pouring cannot be obtained,
If it exceeds 30 parts by weight, the liquid content becomes excessive and a good structure cannot be obtained.

In mortar, it can be easily obtained by adding and kneading 20 to 60 parts by weight, although it varies depending on the type of aggregate and particle size composition.

If it is less than 20 parts by weight, the fluidity required for the mortar cannot be obtained, and if it is more than 60 parts by weight, the adhesion time becomes long and good structure and strength cannot be obtained.

It can also be obtained by kneading the anti-figure aggregate and binder in advance and adding and mixing a hardening agent immediately before construction.

Next, the present invention will be specifically explained with reference to Examples, where all compounding ratios and parts are by weight.

Example 1 Adding viscosity 5 as a binder to 100 parts of the above mixed refractory aggregate
20 parts of a 4:1 mixed solution of 00 cp resol type phenolic resin and ethyl alcohol, 20 parts of a 4:2:4 mixed solution of xylene sulfonic acid, sulfuric acid, and phosphoric acid as a hardening agent based on the resin in the binder. After adding and kneading for 10 minutes, it was poured into a 40 x 40 x 160 M mold and cured at room temperature, and when removed from the frame after 4 hours, it was found to be sufficiently hardened.
No deformation was observed after drying.

Table 1 shows the properties of the product of the present invention in comparison with a product using 20 parts of para-toluenesulfonic acid as a curing agent based on the resin in the binder.

Example 2 100 parts of the blended refractory aggregate of Example 1, 20 parts of a binder consisting of a 4:1 mixed solution of furfuryl alcohol resin and toethyl alcohol, and benzenesulfonic acid, sulfuric acid, phosphoric acid, and boric acid as hardeners. Add 10 parts of a mixed solution with a mixing ratio of 5:2:2:1 to the resin in the binder to make 10
After kneading, the mixture was poured into a 40 x 40 x 160 M mold and cured at room temperature. When the mold was removed after 2 hours, it was found to be sufficiently cured and no deformation was observed after drying.

Table 2 shows the percent properties of the products of the present invention and a product in which 30 parts of para-toluenesulfonic acid was added as a curing agent to the resin in the binder for comparison.

The characteristics of the obtained casting material of the present invention are that it has a curing time of 2 to 4 hours, has strong oxidation resistance when left in an oxidizing atmosphere at 1000° C. for 30 minutes, and has no oxidized layer.

In contrast, Comparative Example 1.2 required a curing time of 12 to 24 hours.

In addition, the oxidation resistance is weak and the surface is oxidized by 2 to 37 Im.

Example 3 The above blended aggregate was hot-kneaded at 150°C, pitch-coated on magnesia grains, and crushed after cooling 9
0 parts and 10 parts of earthy graphite, 20 parts of a 4:4:2 mixed solution of resol type phenol resin, furfuryl alcohol resin and toethyl alcohol as a binder, and xylene sulfonic acid, sulfuric acid, and phosphoric acid as a hardening agent in a ratio of 4:2. : 10 parts of the mixed solution of 4 was added to the resin in the binder, and after kneading for 10 minutes, it was poured into a 40 x 40 x 160 M mold and cured at room temperature. When the frame was removed after 2 hours, it was sufficiently hardened and the No deformation was observed.

Table 3 shows the characteristics of the product of the present invention and a comparison with a product using 20 parts of para-toluenesulfonic acid as a curing agent based on the resin in the binder.

100 parts of the above mixed refractory aggregate, 40 parts of a 4:4:2 mixture of liquid resol-type phenolic resin, ethyl alcohol, and ethylene glycol as a binder, and xylene sulfonic acid, sulfuric acid, and phosphoric acid as hardeners in a ratio of 5:2: A mortar of the present invention was obtained by adding 20 parts of the mixed acid No. 3 to the resin content in the binder.

Example 5 100 parts of the refractory aggregate of the above composition, 20 parts of a mixed solution of resol type phenol resin, furfuryl alcohol resin, and ethyl alcohol 3:3:4 as a binder, and 5:3 of benzenesulfonic acid, sulfuric acid, and phosphoric acid as a hardening agent. A mortar of the present invention was obtained by adding 10 parts of a 2:3 mixed solution to the resin content in the binder.

Table 4 shows the quality characteristics of the products of the present invention in Examples 4 and 5.

100 parts of the above mixed refractory aggregate, liquid resol type phenol resin as a binder, 5 parts of a 2:1 mixed solution of ethyl alcohol, xylene sulfonic acid, sulfuric acid as a hardening agent,
Add 30 parts of phosphoric acid mixed acid with a ratio of 5:2:3 to the resin content in the binder, and after kneading for 10 minutes, a 40x40x16
When poured into a 0 m mold, cured at room temperature, and removed from the frame 2 hours later, it was sufficiently cured and no deformation was observed after drying.

Table 5 shows the characteristics of the present invention.

Claims (1)

[Claims] 1 Consisting of a total of 5 to 60 parts by weight of a binder and a curing agent to 100 parts by weight of the resistant aggregate, and 1 part of the resin in the binder.
The curing agent is 5 to 40 parts by weight per 00 parts by weight, the resin in the binder is a resol type phenolic resin or/and a furan resin, and the curing agent is a mixed acid of an organic sulfonic acid and an inorganic acid including sulfuric acid. , the weight ratio is 90:10~
A self-hardening refractory composition characterized in that the ratio is 10:90.