JPS60246256A - Binder composition for refractory brick - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a binder composition for refractory bricks, which is used for the lining of converters, electric furnaces, blast furnaces, etc. in the production of four-dimension refractory bricks. The present invention relates to a binder composition for firebricks to be used.

(Prior art) Furnaces used in the smelting of metals such as iron, converters, electric furnaces, and other ceramic furnaces used in the ceramic industry are exposed to high temperatures and harsh conditions, so their inner walls are coated with magnesia-carbon-based brick,
The lining is made of refractory bricks such as alumina-carbon bricks and carbonaceous bricks, but these refractory bricks are made by blending a binder with aggregate made of fireproof materials or carbon materials to form a predetermined shape. Manufactured by molding.

Since these refractory bricks are used under harsh conditions at high temperatures, they are required to have a large hot surface and excellent corrosion resistance. For this reason,
The binder used in the manufacture of firebrick also requires strict conditions f1, and it must not only be blended with the aggregate to provide appropriate plasticity, viscosity, or moldability, but also
It is required to have a high residual carbon content, improved hot strength, and excellent oxidation resistance and corrosion resistance.

Conventionally, the binders used to manufacture firebricks for this purpose include pitch-based ones such as petroleum-based pitch and coal-based pitch, and phenolic resin-based ones such as phenolic resin and furan-modified phenolic resin. has been done. By the way, big-based binders are easier to graphitize than phenolic resin-based binders, and when comparing binders alone, pitch-based binders are superior to phenolic resin-based ones, but pitch-based binders ,
In addition to the disadvantages of poor workability during brick manufacturing, such as the need for heating cross-wires and poor filling properties during molding, brick physical properties deteriorate due to expansion during heat treatment, resulting in poor brick performance.
The result is that it is inferior to bricks using phenolic resin binder.

For this reason, phenolic resins have become mainstream as binders for carbon-containing bricks these days.

However, the operating conditions of modern steelmaking kilns are becoming more and more severe year by year, and the durability of phenolic resin binders is beginning to show its limits, and we have no choice but to sacrifice the excellent performance of big binders.

Therefore, in consideration of such problems, a mixed binder has been proposed that combines the advantages of pitch-based and phenol-based binders by blending them in a predetermined ratio. However, even this mixed binder does not satisfy all of the various binder physical properties such as residual carbon content after firing and viscosity-dependent wire crosstalk, and it is not possible to say that this mixed binder satisfies all of the various binder physical properties such as residual carbon content after firing and viscosity-dependent wire crosstalk. There was a need to develop a binder composition.

[Purpose of the invention]

The present invention was devised in view of the above-mentioned viewpoints, and its purpose is to not only produce firebricks with high hot strength and excellent corrosion resistance, but also to have low viscosity and prevent crosstalk. An object of the present invention is to provide a binder composition for refractory bricks which has excellent workability, has a fast curing speed during heat treatment, and has excellent moldability.

[Structure of the Invention] That is, the present invention provides 15 to 65% by weight of phenolic resin.
, contains 1% by weight of purified pitch 7-50% and 18-44% by weight of high-boiling phenols, and the total of these three components is 60% by weight.
This is a binder composition for refractory bricks with a content of Jyusha% or higher.

The phenolic resin used in the present invention is a thermoplastic novolac type phenolic resin made by reacting phenols such as phenol, xylenol, and cresol with formaldehyde in the presence of an acidic catalyst. Although preferred from the viewpoint of workability, thermosetting resol-type phenolic resins obtained by reacting the above phenols with formaldehyde in the presence of a basic catalyst can also be used. Modified phenolic resins modified with hydrocarbons, furan, rosin, lignin, fatty acids, drying oils, etc. may also be used. This phenolic resin has a high residual carbon content when producing firebricks.

5-Although the refined pitch described above may be petroleum-based or coal-based, it is preferably highly aromatic. This refining pip can produce any hydrocarbon,
For example, coal tar, crude oil, naphtha, etc. obtained during coke production are used as raw materials, and it is obtained by means such as distillation and heat treatment.

In addition, the pitch is classified into soft pitch with a softening point of 70°C or less, medium pitch with a softening point of 70 to 85°C, and pitch with a softening point of 85°C.
Although it is classified as hard pitch with a temperature of 5° C. or higher, soft pitch or medium pitch is preferable. Furthermore, these pitches usually contain about 5 to 15 parts of quinolinium solubles in the pitch, but if this quinolinous solubles is present in large quantities, its dispersibility will be affected when used as a binder for refractory bricks. It not only has a negative effect on the storage stability but also reduces the strength of the refractory bricks produced in the bundle.
% or less, more preferably 0.1% or less.

This refined pitch not only has a high residual carbon content when producing refractory bricks, but also exhibits excellent binder properties.

The high boiling point phenols used with the above purified pitch include cresols, 2,3-xylenol, 2,4-
Xylenol, 2.5-xylenol, 2.6-xylenol and other xylenol, 2.4.6-t-limethylphenol and other trimethylphenol, ethylphenol, methyl/ethylphenol, etc. . Such high-boiling phenols may be a single compound or a mixture containing two or more compounds. It may be an acid, but preferably 2,4
- It is a xylenol reservoir. These high boiling point phenols also exhibit a high residual carbon content like the above-mentioned phenolic resins and purified pitches1, and also exhibit excellent compatibility with both phenolic resins and purified pitches, and when producing refractory bricks, phenolic resins Reacts with the carbon to create strong carbon bonds, improving the strength of firebricks.

In the present invention, in addition to the above-mentioned components, other components such as high-boiling aromatic hydrocarbon oil, alcoholic solvent, water,
A surfactant or the like may be added for the purpose of improving compatibility or reducing viscosity.

High-boiling aromatic hydrocarbon oils used for this purpose include alkylbenzenes, naphthalenes, alkylnaphthalenes, an-1-hracenes, dolphins, dibenzofurans, fluorenes, and nanthrenes. Examples include hydrocarbon oils consisting of one type or two or more types of hydrocarbon oils, and distillates containing FJ nonthrene are preferred. This J, eel distillation is a tar oil obtained by distilling rutar or a neutral oil obtained by refining this, and there is one with a boiling point range of 185 to 370°C. Examples of alcohol-based solvents include glycols such as ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, and hexylene glycol; glycerin such as glycerin and diglycerin; Monoalcohols such as methanol, octyl alcohol, nonyl alcohol, etc.
The following examples can be mentioned.

Although the above-mentioned high-boiling aromatic hydrocarbon oil is lipophilic, it exhibits excellent compatibility with phenolic resins, refined pitch, and high-boiling phenols. In addition, alcohol-based solvents exhibit excellent solubility in phenolic resins, and
It shows affinity for aggregate during the production of firebrick and improves the compatibility between the binder composition and fR material. Furthermore, water exhibits excellent affinity for both phenolic resins and aggregates, and surfactants contribute to the dispersion stability of the binder composition and improve the affinity between the binder composition and aggregates. Ru.

Regarding the blending ratio of the above phenol resin, purified pitch, and high boiling point phenols, the phenol resin is 15 to 65%.
% by weight, preferably 20-60% by weight, more preferably 30-50% by weight, and purified pitch is 7-50% by weight.
, preferably 8 to 40% by weight, more preferably 10 to 2% by weight
0 heavy market%, and high boiling point phenols are 18-4%.
Quadruple opening%, preferably 20 to 40% by weight, and grinding of these three components is 60% by weight or more, preferably 1.170
% by weight or more, more preferably 80Φ hanging% or more.

Regarding phenolic resin, if the blending ratio is low, the residual carbon content will decrease and the hot strength will deteriorate, and the gel time will also become long.On the other hand, if the blending ratio is too high, the viscosity will become too high, and if t) Improved physical properties of refractory bricks. As for refined pitch, if the mixing ratio is small, the residual coal rate will decrease, and the refractory brick f1 will also be changed. Also becomes longer. Rough, high boiling white) J
Nors not only improve the compatibility of the phenolic resin and purified pitch, but also react with rimethylenetetramine to be used as a curing agent and contribute to the residual carbon ratio. Familiarity with the subject decreases.

In addition, when the above-mentioned high-boiling aromatic hydrocarbon oil, al-1-al solvent, water, and surfactant are blended, the blending ratio is usually 1 to 5 for the high-boiling aromatic hydrocarbon oil.
Width cutting %, preferably l; L 2-4 weight - 10- lifting %, usually 5-20
% by weight, preferably 7 to 15% by weight, and for water usually 1 to 5% by weight, preferably 2 to 4% by weight,
Further, the surfactant content is usually 0.5 to 5% by weight, preferably 1 to 4% by weight. These high-boiling aromatic hydrocarbon oils, alcoholic solvents, water, and surfactants are used to improve the viscosity and dispersibility when preparing the binder composition, or when producing or producing firebricks. It is added as appropriate within the above range, taking into account the charcoal content, gel time, etc.

How to prepare the binder composition of the present invention? When reading, ]-
phenolic resin, purified pitch and high-boiling phenols, or in addition to these, the above-mentioned high-boiling aromatic hydrocarbon oil,
The alcoholic solvent, water, and surfactant may be blended in a predetermined ratio and dissolved uniformly.

The binder composition of the present invention can be used in the same manner as conventionally known binders. When producing firebrick, it is sufficient to mix 11- into the aggregate at a predetermined ratio, press it into the shape of a brick, dry it, and then fire it at a predetermined temperature. As the aggregate for which the binder composition of the present invention can be used, a wide range of conventionally known aggregates can be mentioned.Specifically, fireproof materials include magnesia-based materials, magnesia-chromium-based materials, chromium-magnesia-based materials, and magnesia-based materials. -Dolomite type,
There are carbon materials such as dome 1 type, alumina type, clay, silicon carbide, etc., and carbon materials such as earthy graphite, natural graphite, artificial graphite, electrode scrap, petroleum coke, foundry coke, carbon black, pitch coke, etc. These refractory materials and carbon materials can be arbitrarily combined and used as aggregates. The blending ratio of aggregate and binder composition when producing firebrick is usually 1 to 10 parts by weight, preferably 3 to 6 parts by weight of binder composition per 100 parts by weight of aggregate. .

Furthermore, in the present invention, when a novolak type phenol resin is used as the phenol resin, hexamethylenetetra-12-mine or the like is blended as a hardening agent when producing a firebrick using the binder composition. .

(Examples) Hereinafter, the binder composition of the present invention will be specifically explained based on Examples and Comparative Examples.

Examples 1 to 13 and Comparative Examples 1 to 5 Novolak-type phenolic resin (formalin/Nol molar ratio 0.7), purified pitch (softening point 36°C, quinoline solubility 0.02%), high boiling point phenols As 2.
A xylenol distillate mainly containing 4-xylenol with a boiling point of 200 to 215°C, an aromatic hydrocarbon oil containing phenanthrene and having a boiling point of 250°C or higher, ethylene glycol, water and a surfactant as shown in Table 1. A binder composition was prepared by blending the components in the following proportions and uniformly mixing them at room temperature while stirring.

The residual carbon percentage, viscosity, gel time, and dispersibility of the binder compositions of each example and comparative example were measured. Regarding the residual carbon percentage, take a sample of 2g into a crucible, weigh it, cover it and burn it in an electric furnace at 750℃ for about 7 minutes, weigh the residue, and calculate the weight ratio. It was taken as the residual coal rate. Also, regarding gel time,
A 5 g sample was taken into a test tube, heated in an oil bath at 200°C, and the time until the contents lost fluidity was measured, and this time was determined as the gel time. J: The dispersibility and overall evaluation were determined using a four-step evaluation method of excellent, good, fair, and poor. The results are shown in Table 1.

As is clear from the above Examples 1 to 13 and Comparative Examples 1 to 2, the binder compositions of each Example had a residual carbon content of 42% by weight or more and a viscosity of 70 ρoise, which were determined as comprehensive criteria.
It was found to be excellent as a binder, satisfying all of the following conditions and a gel time of 150 seconds or less. On the other hand, the binder compositions of each comparative example have problems in terms of viscosity or residual carbon percentage, respectively.
It is inferior to the binder compositions of each example.

Next, a mixture of 77 medium parts of magnesia clinker, 20 parts of natural graphite, and 5 parts of metal skewers was used as an aggregate, and the binder compositions of Examples 1 to 4 and the binder were added to this mixture. 15% by weight of hexamethylene 1-lamin 14- etc. were added to the composition in the ratio shown in Table 2, and kneaded at room temperature using a kneader, and then mixed at a pressure of 1800 kg/cI+i to 500 MX.
Molded to a size of 150awX 150m/140m,
It was heat treated at 350° C. for 48 hours to harden and obtain a refractory brick. In addition, as Comparative Examples 3 and 4, we used a phenolic resin binder modified with petroleum-based pitch that has been conventionally used (Comparative Example 3: non-volatile content 63.0% by volume, fixed carbon 4%).
0% by weight; Comparative Example 4: nonvolatile content 73.0% by weight, fixed carbon 44% by weight), and Comparative Example 5 using a phenolic resin binder (nonvolatile content 68.7% by weight, fixed carbon 50% by weight) ), and a refractory brick was obtained in the same manner as the binder composition of Example 1.

Physical properties of the cured product and 1 (')00 of the firebricks using the binders of the ten examples and comparative examples.
The physical properties after reduction firing at ℃ were investigated. The corrosion test was evaluated using a four-level evaluation method: corrosion, good, fair, and poor.

The results are shown in Table 2.

As is clear from Table 2, the refractory bricks manufactured using the binder compositions of Examples 1 to 4 had -15 = -15=compared to the refractory bricks manufactured using the binders of Comparative Examples 1 to 3. especially)! It was found that it exhibited excellent performance in hot bending and corrosion tests after firing.

16- [Effects of the Invention] The binder composition for refractory bricks of the present invention can produce refractory bricks with a high residual carbon content and excellent hot strength and corrosion resistance by blending with appropriate aggregates and appropriate proportions. Not only can it be manufactured, but it has a low viscosity, a fast curing speed during firing, and excellent moldability, so it significantly improves the workability of cross-wires and molding when manufacturing firebricks. be.

Patent applicant Nippon Steel Chemical Co., Ltd. Kurosaki Ceramics Co., Ltd. Agent Patent attorney Masaru Naruse Same as Tomohiro Nakamura 18- 336-

Claims (4)

[Claims] (1) Phenol resin 15-65% by weight, purified pitchfur 50% by weight and high boiling point phenols 18-44% by weight
A binder composition for firebrick, characterized in that the total of these three components is 60% or more by weight. (2) The binder composition brick for refractories according to claim 1, wherein the phenolic resin is a novolac type phenolic resin. (3) Claim 1, in which the purified pitch is a soft pitch with a softening point of 70°C or less obtained by separating and removing quinolinous components.
The binder composition for firebricks according to item 1 or 2. (4) The binder composition for firebricks according to claim 1 or 3, wherein the i1% boiling point phenol is 2,4-xylenol distillate.