JPS589781B2 - Binder for irregular shaped furnace materials for blast furnaces - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a binder for amorphous blast furnace material, and an object thereof is to provide a blast furnace material that has a short curing time, high hot strength, and excellent corrosion resistance. It is in.

In recent years, in the metallurgical industry, monolithic furnace materials for blast furnaces, such as taphole plugging materials, trough materials, and repair materials, have been used in blast furnaces and refractory equipment in high-temperature atmospheres.

The main components of such amorphous furnace materials for blast furnaces are so-called aggregates such as chamotte powder, silicon carbide powder, alumina powder, magnesia powder, coke powder, and other refractory powders, but such aggregates are simply mixed together. Plasticity and adhesion cannot be obtained just by
Therefore, binders are added to irregular-shaped blast furnace materials to impart plasticity and adhesive properties.

Coal tar has been known as a binder for unshaped blast furnace materials, which are conventionally blended into unshaped blast furnace materials such as taphole plugging materials, trough materials, and repair materials.

Amorphous blast furnace materials using this binder take a long time to cure, and the cured product obtained by curing has insufficient hot strength and cannot provide excellent corrosion resistance.

Therefore, when such an irregular blast furnace material is used as a taphole plug, for example, it tends to cause roughness in a short period of time, and when the tap hole is closed, the plug does not harden sufficiently. It is necessary to press the taphole with a taphole obturator for 40 to 60 minutes before it gains strength, and even then, tap leakage often occurs.

In view of the current situation, the present inventors have conducted extensive research in order to develop an unshaped blast furnace material that satisfies all of the above conditions.

As a result, a mixture of a thermosetting resin with a melting point of 65 to 85°C, hexamethylenetetramine, and glycol is obtained by condensing crude tar acid obtained by extraction and separation from coke oven tar and formaldehyde in the presence of an acidic catalyst. It has been found that a desired monolithic blast furnace material can be obtained when used as a binder.

The present invention was completed based on this knowledge.

That is, the present invention uses a thermosetting resin, hexamethylenetetramine, and glycol having a melting point of 65 to 85°C obtained by condensing crude tar acid obtained by extraction and separation from coke oven tar and formaldehyde in the presence of an acidic catalyst. It relates to a binder for amorphous blast furnace material, which is characterized by containing:

By using the binder for the amorphous blast furnace material of the present invention (hereinafter referred to as "the composition of the present invention"), it can be easily kneaded with aggregate.

Further, by blending the composition of the present invention, suitable plasticity and adhesiveness can be imparted to the obtained irregular-shaped blast furnace material.

The amorphous blast furnace material has good storage stability and is also excellent in workability at high temperatures.

Furthermore, the amorphous blast furnace material obtained by blending the composition of the present invention has a short curing time, and the hot strength of the cured product obtained by curing is also large and has excellent corrosion resistance (hot metal resistance and slag resistance). properties) can be imparted to the cured product.

As described above, the unshaped blast furnace material obtained by blending the composition of the present invention as a binder satisfies the above-mentioned conditions and is therefore suitable for use as taphole plugging material, gutter material, repair material, etc. obtain.

In the present invention, a thermosetting resin having a melting point of 65 to 85° C. is used, which is obtained by condensing crude tar acid obtained by extraction and separation from coke oven tar and formaldehyde in the presence of an acidic catalyst.

Such a thermosetting resin is a known resin, and has a methylene bond (-CH2-) and a methylene ether bond (-
It is an alcohol-soluble novolak type resin having CH2OCH2-).

The resin is prepared by mixing 1 mole of crude tar acid and 1 mole or less (preferably 0.7 to 0.85 mole) of formaldehyde in the presence of a known acidic catalyst such as hydrochloric acid or oxalic acid at about 80 to 120°C for 2 to 8 hours. It is easily produced by carrying out a condensation reaction for about a period of time, followed by dehydration under reduced pressure.

The crude tar acid used as a raw material here is usually contained in about 4% of tar separated from a coke oven in a steel mill, and is obtained as a by-product of the coal carbonization industry.

This crude tar acid is usually produced by alkali extraction of carbol oil fraction and acid decomposition of this alkaline extract.

The composition of the tar acid excluding water is approximately as shown in Table 1 below.

The boiling point of the tar acid is approximately within the range of 180 to 240°C, and the crude tar acid is used as it is for producing the thermosetting resin without further separation or purification.

In the present invention, it is essential to use a thermosetting resin having a melting point of 65 to 85°C.

When using a thermosetting resin with a melting point exceeding 85°C, the viscosity of the composition of the present invention becomes extremely high, making it difficult to mix with aggregate, and the curing speed becomes extremely high, resulting in poor workability at high temperatures. This results in the disadvantage that it is inferior to

Furthermore, thermosetting resins with a melting point lower than 65°C contain a large amount of unreacted tar acid, and even if such thermosetting resins are used, the intended purpose of the present invention cannot be achieved. I don't get it.

Hexamethylenetetramine is blended into the composition of the present invention.

The amount of hexamethylenetetramine blended is not particularly limited and may be appropriately selected within a wide range, but it is usually 0.1 to 10% by weight (hereinafter simply referred to as "%") based on the thermosetting resin.
), preferably in an amount of about 0.5 to 5%.

If the amount of hexamethylenetetramine blended is too large, the curing rate will be extremely high, and the taphole plugging material will solidify in the taphole plug, which will tend to reduce the workability before the furnace.

Furthermore, if the amount of hexamethylenetetramine blended is too small, the curing speed will be extremely slow and the hot strength of the resulting cured product will be insufficient, resulting in a tendency for the corrosion resistance to decrease.

The composition of the present invention also contains glycol.

As the glycol, a wide variety of known glycols can be used as long as they can dissolve the thermosetting resin and impart plasticity to the amorphous blast furnace material. Specifically, ethylene glycol,
Thiethylene glycol, glopylene glycol, trimethylene glycol, 1,4-butanesiol, 1,5-
Pentanediol, 1,6-hexanesiol, 1,7
-heptanediol, 1,8-octanediol, 1.
Examples include 9-nonanediol, 1,10-decanediol, and pinacol.

In the present invention, it is particularly preferable to use at least one kind selected from the group consisting of ethylene glycol, diethylene glycol and glopylene glycol as the glycol.

Furthermore, there is no problem even if the glycol used in the present invention contains a small amount of water as an impurity.

The amount of glycol to be blended is not particularly limited and may be added as appropriate within a wide range, but the glycol may be used so that the amount of the thermosetting resin contained in the glycol is generally 40 to 70%.

If the blending amount of glycol is too large, the hot strength of the cured product obtained by curing the amorphous blast furnace material tends to decrease.

Furthermore, if the amount of glycol blended is too small, the viscosity of the composition of the present invention tends to be too high, making it difficult to knead with aggregate.

Another feature of the present invention is the use of glycol; for example, if methanol, which is a monohydric alcohol, is used, the resulting amorphous furnace material will have poor workability at high temperatures and will be difficult to harden. The cured product obtained by this process also has insufficient hot strength and cannot impart excellent corrosion resistance.

Therefore, when such amorphous furnace material for blast furnaces is used, for example, as a taphole plugging material, methanol volatilizes during work, polluting the working environment, and the viscosity of the plugging material increases, reducing work efficiency. Moreover, due to its poor corrosion resistance, it tends to cause roughness in the tap in a short period of time.

There are no particular limitations when preparing the composition of the present invention, but
A preferable example thereof is the method shown below.

That is, the composition of the present invention is prepared by dissolving the above thermosetting resin in glycol and then dissolving or mixing and dispersing a predetermined amount of hexamethylenetetramine in this solution.

In the present invention, hexamethylenetetramine may be blended in advance into the composition of the present invention, or the glycol solution of the thermosetting resin and hexamethylenetetramine may be mixed at the time of use to form the composition of the present invention. good.

There are no particular restrictions on the use of the composition of the present invention, and it may be used in the same manner as conventionally known binders for irregular shaped blast furnace materials.

For example, the composition of the present invention may be mixed with a suitable aggregate and used as an unshaped blast furnace material in the fields of taphole plugging material, gutter material, repair material, and the like.

As the aggregate, a wide variety of aggregates known in this field can be used.

The composition of the present invention generally contains 30 to 4 parts by weight per 100 parts by weight of aggregate.
They may be mixed at a ratio of 0 parts by weight.

Examples and comparative examples are given below to further clarify the present invention.

Note that "parts" simply means "parts by weight."

Example 1 Crude tar acid (composition: phenol 31.4%, 0-cresol 11.0%, m- and p-cresol 31.8%
, 2,4- and 2,5-xylenol 7.1%, 2,3
- and 3,5-xylenol 6.2%, 3,4-xylenol 0.5% and high boiling point components 12.0%) 1 mol, formaldehyde 0.8 mol and oxalic acid 0.4% (based on crude tar acid) ) was heated to reflux for 210 minutes to cause a condensation reaction.

The reaction mixture is then dehydrated under reduced pressure of 100 mmHg to obtain a dark brown thermosetting resin with a melting point of 79°C.

58 parts of the resin was heated and dissolved in 42 parts of ethylene glycol, then cooled, and then 1 part of hexamethylenetetramine was dissolved.
A further 94 parts are added and dissolved at 45°C to obtain a composition of the present invention.

The viscosity of the composition was 27,000 cps at 30°C.

43 parts chamotte, 12 parts fireclay and 20 parts coke powder
25 parts of the composition of the present invention is added to the mixture and kneaded to obtain an unshaped blast furnace material.

The furnace material has appropriate plasticity and adhesiveness, and when used as a taphole plug in a blast furnace, it hardens in an extremely short time of 5 minutes and prevents seizure inside the taphole plug. It was in good used condition.

Example 2 50% of the thermosetting resin with a melting point of 79°C obtained in Example 1
A composition of the present invention having a viscosity of 20,000 cps at 30° C. is obtained by uniformly dispersing 2.2 parts of hexamethylenetetramine in 100 parts of diethylene glycol solution at room temperature.

43 parts chamotte, 12 parts fireclay and 20 parts coke powder
22 parts of the composition of the present invention is added to the mixture and kneaded to obtain an unshaped blast furnace material.

Example 3 1 mol of crude tar acid, 0.75 mol of formaldehyde, and 0.7% of oxalic acid (based on crude tar acid) having the same composition as in Example 1 are heated and refluxed for 200 minutes to cause a condensation reaction.

The reaction mixture is then dehydrated under reduced pressure of 100,712 ffl Hg to yield a dark brown thermosetting resin with a melting point of 74°C.

Add 1.15 parts of hexamethylenetetramine to 100 parts of a 60% diethylene glycol solution of the resin and dissolve at 42°C, so that the viscosity at 30°C is 40000 cp.
A composition of the present invention which is s is obtained.

43 parts of chamotte, 12 parts of clay, and 20 parts of coke powder
24 parts of the composition of the present invention is added to the mixture and kneaded to obtain an unshaped blast furnace material.

Comparative Example 1 Coal tar is used as a binder for amorphous blast furnace material.

An unshaped blast furnace material is obtained in the same manner as in Example 1 except that 25 parts of coal tar is used.

Comparative Example 2 A binder for amorphous blast furnace material was obtained in the same manner as in Example 1 except that 42 parts of methanol was used instead of 42 parts of ethylene glycol.

Further, an irregular furnace material for a blast furnace is obtained in the same manner as in Example 1 except that 25 parts of the binder is used.

The amorphous blast furnace materials obtained in Examples 1 to 3 and Comparative Examples 1 to 2 were cured in a nitrogen stream at 600°C for 60 minutes to obtain a cured product (size: 30 x 30 x 15 ”0
%).

The hot bending strength of these cured products at 600°C and 1200°C is measured in a nitrogen stream.

The results are shown in Table 2 below.

It can be seen from Table 2 above that when the composition of the present invention is used as a binder, the hot strength of the cured product can be significantly improved compared to conventional binders.

In addition, the unshaped blast furnace materials obtained in Examples 1 to 3 and Comparative Example 1 were heated for 5 minutes in an electric furnace kept at 600°C.
The hot bending strength of the obtained fired body at 600° C. is measured in the same manner as above.

The results are shown in Table 3 below.

It can be seen from Table 3 above that when the composition of the present invention is used as a binder, the curing speed increases and the time required for curing is significantly shortened compared to conventional binders.

Example 4 25 parts of the composition of the present invention obtained in Example 1, 15 parts of alumina,
20 parts of clay, 15 parts of silicon carbide, and 15 parts of coke were sufficiently kneaded to obtain an unshaped furnace material.

Comparative Example 3 In Example 4, a nopolac type phenolic resin was used instead of the composition of the present invention, and all other conditions were used. Comparative Example 4 In Example 4, sp nignin and phenolic resin ( An unshaped furnace material was obtained in the same manner as in Example 4, except that a mixture with a 1:1 weight ratio) was used.

Comparative Example 5 In Example 4, a resol type phenolic resin aqueous solution and a powdered novolac type phenol resin (6:4 weight ratio) were used instead of the composition of the present invention, and all other conditions were the same as in Example 4. A shaped furnace material was obtained.

The physical properties of various types of furnace materials were measured for the warehouse irregular-shaped furnace materials of Example 4 and Comparative Examples 3 to 5.

The results are shown in Table 4 below.

Each physical property in Table 4 above was measured as follows.

Corrosion resistance: Slag was placed in a rotating arc furnace lined with sample furnace material, and the temperature was raised to 1550° C. while rotating, and the amount of erosion of the furnace material at that time was measured.

Note that the amount of erosion in Comparative Example 3 was expressed as 100.

Chickentropy index: Expressed as the ratio (μ0/μ1) of the initial viscosity (μ) and the viscosity (μ1) after high shear rate treatment (when rotated at 450 rpm).

Plasticity: Observed with the naked eye.

Claims (1)

[Claims] 1. A thermosetting resin with a melting point of 65 to 85°C obtained by condensing crude tar acid obtained by extraction and separation from coke oven tar and formaldehyde in the presence of an acidic catalyst;
A binder for amorphous blast furnace material, characterized by containing hexamethylenetetramine and glycol. 2. The binder according to claim 1, wherein the glycol is at least one selected from the group consisting of ethylene glycol, diethylene glycol, and propylene glycol. 3. The binder according to claim 1 or 2, wherein the blending ratio of the thermosetting resin and hexamethylenetetramine is 0.1 to 10% by weight relative to the former. 4. Binder according to claim 3, wherein the blending ratio of the thermosetting resin and hexamethylenetetramine is 0.5 to 5% by weight relative to the former. 5. Blend of the thermosetting resin and glycol. The binder according to any one of claims 1 to 4, wherein the ratio is 40 to 70:60 to 30 (weight ratio).