JPS5869782A - Indefinite form refractories - 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 The present invention relates to a monolithic refractory having excellent corrosion resistance, spalling resistance, and workability. This relates to monolithic refractories made of materials with added

Conventionally, hydraulic alumina cement, clay, phosphate, etc. have been used as binders for monolithic refractories that harden at room temperature.

However, when these substances are used as binders, the following drawbacks have been pointed out.

That is, (1) when hydraulic alumina cement is used, it exhibits a decrease in strength in the intermediate temperature range of 500 to 1200°C, or an explosive phenomenon occurs when the temperature rises.

(2) When clay is used as a binder, there is a problem in corrosion resistance at high temperatures.

(3) In the case of phosphates, it is unfavorable from the viewpoint of the quality of the steel, and when used in steel manufacturing, the amount of phosphate added is limited, so the resulting construction body must exhibit sufficient strength. I can't.

etc.

On the other hand, in recent years, carbon bonds have been attracting attention due to their excellent strength at high temperatures, heat spalling resistance, and explosion resistance.

As is well known, these are prepared using tar and pitch, but these tar and pitch do not emit smoke or other melting agents, and are said to contain carcinogenic substances. , 70 Use #'i environmental hygiene precautions are also mentioned.

Furthermore, monolithic refractories using tar or pitch soften once during temperature rise and then generate carbon pounds, so they could not be used as lining structures for various molten metal cormorant containers.

Therefore, in order to avoid the environmental and work problems mentioned above, thermoplastic resins that exhibit thermosetting properties are used in combination with thermosetting resins and curing agents such as hexamethylenetetramine. method is receiving increasing attention.

However, these resins themselves do not have curability at room temperature, so even if they can be used for shaped refractories, when used for monolithic refractories, they must be made curable at room temperature by some method.

Methods to avoid this are: (1) Add alumina cement or phosphate to a resin that does not harden at room temperature, and use the alumina cement or phosphate to exhibit room temperature hardenability (2) Thermosetting A method of adding a curing agent such as acetic acid or para-toluene sulfonic acid.

There is.

Tojiroga method (1) is carried out by mixing with water, so when the resulting construction material is dried and heated, it is likely to explode due to evaporation of water, or even if it does not burst, it may become porous or Since the resin sometimes inhibits the formation of carbon bonds, the effect of adding the resin cannot be fully exhibited.

In addition, method (2) generally uses liquid thermosetting IN resin as a curette, and is an ideal method from the point of view of generating carbon bonds, but this room temperature curing method is also called acid curing. Because strong acids such as paratoluenesulfonic acid, benzenesulfonic acid, sulfuric acid, and phosphoric acid are used, it can be applied to neutral or acidic refractory materials, but it cannot be applied to basic refractory materials such as magnesia and dolomite. could not be applied. That is, in the case of basic refractory materials, these strong acids as curing agents cause a neutralization reaction with the refractory material, so that curing takes a long time or curing does not proceed.

The present inventors conducted various studies in order to obtain a room-temperature curable monolithic refractory that overcomes the drawbacks of the prior art described above, and found that if a thermosetting resin and further lactams are added to the refractory material, The inventors have discovered that alFi, a naturally hardening tree, can be given constant Mtg properties, leading to the present invention.

That is, the present invention aims to provide a monolithic refractory material which is made of a refractory material as a main material and which has thermosetting resin and lactams and is curable at room temperature.

The refractory materials used in this invention include various conventionally known basic, neutral, and acidic refractory materials, including cypress magnesia refractories such as fused magnesia and sintered magnesia, and stabilized F 1 type or 2m or more of various dolomite refractory materials such as Lomiteya synthetic dolomite and graphite,
It is preferable to use powdered or granular carbonaceous substances such as charcoal-fired silicon in combination.

In addition, thermosetting m#In includes phenol, 7ran,
Various resins such as epoxy, melamine, and other resins that become thermosetting by adding hexamethylenetetramine may be used, but phenol resins and 7-run resins are particularly preferred.

Further, these wrenches may be used alone or in combination with F12@ or more, and thermoplastic wolds, pitch, resinous pitch, organic core materials, etc. may be used in combination.

The use of this thermosetting resin is 0.0% compared to fireproof materials.
6-80'hLii%, preferably ti 1.5-25
Weight%.

If the amount of thermosetting JfN resin is less than 0.5% by weight, sufficient carbon bond will not be generated, resulting in insufficient strength of the resulting construction body, and if the amount of thermosetting JfN resin is less than 0.5% by weight, This is because if a large amount is used, the volatile content increases, which deteriorates the physical properties and corrosion resistance of the construction body after heat treatment, which is not preferable.

Furthermore, the lactams used in this invention include:
Examples include ε-caprolactam, oxidol, isatin, and glycocyanidin, and these may be used in combination of two or more types of i4 or Fi.

The use of these lactams is 0.2~ for M#i refractory materials.
1O1X'rjk%, good IL<aO, 16° for 5-81Em goose, which is less than 0.2% by weight II! 11
The room-temperature curing properties of 462-grade cypress resin cannot be fully demonstrated, and a long curing time is required, the strength after curing or the ability to maintain the shape of the construction body during heating is insufficient, and the 1O2 weight ratio is too low. This is because if the amount is too large, the physical properties and corrosion resistance of the resulting construction object will be poor.

Furthermore, in addition to the above-mentioned thermosetting resin and lactams, it is also possible to use an alkaline component in combination with the room temperature curing rate (il-
This is effective for adjustment and is one of the features of this invention.

The amount added is 1.0% as NaOH to the refractory material.
It is suitably 5% by weight or less, preferably 11.0% by weight or more.

In addition to NaOH, such alkaline components include KOH, NH40H, Ca (OB)2, CaC01
, Mg (OH) g, and other inorganic alkali components and organic alkali components can be used. Among these, Ca(OH)g (including dolomite powder) is particularly effective.

In addition, when adding to neutral or acidic refractory materials, NaOH
Only alkaline components such as and KOH (CaO.

It is preferable to use a part of fine powder such as λtgO in combination.

Is this a single VCNaOH? With just an alkaline component such as KOH, the amount added is large due to the Vi curing speed KfM node, and as a result, the corrosion resistance of the f#r large product made is poor, and MgO.

CaO alone has a slow curing speed, which is disadvantageous.The effect of using this alkaline component in combination is that the alkaline component easily opens the lactams, creates a crosslinked structure in the thermosetting #1 fatty acid, and accelerates curing. I'm good at thinking about things.

Since the monolithic refractory of the present invention has room temperature curability, it is preferable to use cross-wire at the construction site, but it is also possible to use 6Ji to produce special-shaped monolithic refractories. In addition, these construction methods include simple pouring construction, vibration molding construction, and combing (including stamping) construction, but depending on the application and construction method, thermosetting m
The type, combination, and amount of B and lactams to be used may be adjusted5.The advantages of the monolithic refractory of the present invention obtained in this way are as follows.

(1) Regardless of whether the refractory material is acidic, neutral or basic, it has room temperature curability and workability.

(2) The curing speed of the construction body can be easily adjusted by simply changing the amount of lactam and alkali components used.

(3) Unlike conventional castables, no water is used, so there is no explosion or cracking when drying.

(4) It has stable strength from normal conditions to temperatures, and has excellent shape retention of the constructed body.

(5) Because it forms a carbon bond with a liquid component that provides workability, it not only has greater bending strength at high temperatures than ceramic bond, but also has high heat spalling resistance.

(6) Because it forms a carbon bond, it has excellent corrosion resistance when wet with molten steel or slag.

(7) Excellent adhesion to steel shells, bricks, etc.

(8) Digestible refractory materials such as synthetic dolomite can also be used.

Next, examples of the present invention will be described.

Note that all parts and *Fi described in the formulation are parts by weight and weight %.

゛'Example 1 Liquid resol type phenolic resin (viscosity 90 cp, pH 6.8) or powdered resol type phenolic resin in the amount shown in Table 1 was added to a refractory material consisting of 90 parts of magnesia and 10 parts of graphite whose particle size had been adjusted. and 6-caprolactam were added and kneaded for about 8 minutes using a mortar mixer to obtain a monolithic refractory.

The workable time and curing time of this monolithic refractory were measured and the results are shown in Table 1.

The working time is defined as the time required to measure the free flow value at regular intervals after crosstalk using a mortar 70 tester specified in JISR5201, and until the free flow value shows a value of 150■ or more. . The curing time is defined as the time required for the hardness of the sample poured after kneading to show a hardness of 80 or higher using a Shinrai Kogyo Green Bird Tester (7c).

Example 1 and Example 11 were tested to obtain fire resistance and heat resistance, except that para-toluene sulfonic acid was used as a curing agent for the phenolic resin in the comparative example.

As shown in Table 1 above, even if a basic refractory material such as magnesia is used, by using a thermosetting resin and a lactam together, it will have curability at room temperature and both It has been found that the curing speed can be adjusted by changing the ratio of the .

On the other hand, in the acid curing method using para-toluenesulfonic acid as in the comparative example, the curing speed is slow, and when the amount added is increased to speed up the curing speed, heat generation due to neutralization reaction with the basic refractory material occurs. It was found that foaming increased and it could not be used as a monolithic refractory.

Example 2 Particle size adjusted magnesia 86g and natural graphite 15
A liquid resol type phenol resin, ε-caprolactam ao* alcohol solution, and NaOH2096 water base liquid were added to the refractory made of s in the amounts shown in Table 1, and a monolithic refractory was obtained in the same manner as in Example 1. , its workable time and curing time were measured.

The results are shown in the IN2 table.

From Table 2, it was established that the curing speed of the monolithic refractory according to the present invention can be freely adjusted by adjusting the amount of Phulkali component added.

Example 8 Various alkali components shown in Table 8 were added to a refractory material consisting of 75 parts of alumina, 15 parts of silicon carbide, and graphite 1Os whose particle size had been adjusted, and further 118 parts of liquid resol type phenol resin 11, and 80 g of ε-caprolactam. 5 parts of alcohol solution was added and kneaded for about 8 minutes using a mortar mixer to prepare a sample.

Next, using this sample, the workable time and curing time were measured in the same manner as in Example 1, and the results shown in Table 8 were obtained.

Part 4, Table 8 From Table 8 above, the monolithic refractory of the present invention not only allows the curing speed to be adjusted by adding an alkali component, but also allows the type and amount of the alkali component to be selected depending on the intended use. Gaa! It was necessary.

Example 4 Refractory materials, phenolic resin 1, lactams, alkali components, etc. were blended as shown in Table 4, mixed in a mortar mixer for about 8 minutes, poured into a 100 x 100 x 200 square frame, and mixed in the same manner as in Example 1. The curing time was measured by the method. Furthermore, 1. Samples that had been hardened until the green hardness tester showed a value of 98 or higher were cut out, and the thermal bending strength was measured at each temperature (reducing atmosphere) shown in Table 4.

These results are shown in Table 4.

Table 4 Note: Rice 1: In the formulation of Comparative Example 8, in addition to the above, 0.5 parts of surfactant, 18 fl of water, and 2 s of sodium hexametaphosphate were added.

Rice 2: In addition to the above, 0.5 $ of surfactant, 14 parts of water, and 8 parts of alumina cement were added to the mixture of Kitasoft Example 4.

From Table 4 above, it was found that the monolithic refractory according to the present invention maintains stable strength from dazzling temperatures to high temperatures.

Example 5 A sample with the composition shown in No. 5 was poured into a 200 x 200 x 150 square frame, cured in a room for 24 hours, then taken out, the 200 x 200 square side facing into the furnace, and the other side filled with other refractory material. I remembered this and placed it on the side wall of the gas furnace.

The temperature of this gas furnace is 5℃/-, 800℃.
The sample was heated at an increasing rate of FitO°C/- from 1100°C to 1100°C, and the presence or absence of rattan was observed.

Next, the same sample as above was heated to 800℃ at a heating rate of 8℃/-゛, and heat-treated at the same temperature for 5 hours.
It was cut into pieces of 100 cm in size, coated with an antioxidant on the surface, kept in an electric furnace at 1000° C. and humidity for one hour, cooled, and then taken out to serve as a sample for the following spalling test.

This sample was pushed into an electric furnace maintained at 1200°C, and
After holding for 5 minutes, it was taken out and allowed to cool for 30 minutes.

This operation was repeated to measure the same number of samples until a crank appeared on the surface of the sample. These results are shown in Table 5.

As a comparative example, glazes using both phosphate and 7-enol camphor glaze and glazes using only a hydraulic binder were tested.
The sample was dried at 00°C for 12 hours.

As is clear from Table 6 and Table 5, the monolithic refractory according to the present invention does not become refractory even if the temperature is slowly raised immediately after demolding, but the comparative example using a hydraulic binder does not. Shaped refractories: 600℃
What is fascinating and also uses a combination of phenolic resin and phosphate is the field! l! However, the sample after the test showed -
Internal cracks reaching the S surface had occurred.

In addition, regarding the spalling resistance, the monolithic refractory #'i according to the present invention showed a service life of 8 times or more, and was recognized to have an excellent service life of about 2.6 to 8 times as compared to the comparative example.

In order to investigate the corrosion resistance of the monolithic refractories according to the invention in Examples, a slag test was conducted using a horizontal rotating slag test WIL&.

Nine pieces of each sample were taken out from the test lamp and formed into a hexagonal shape, and in this crucible was added steelworks A converter slag (C/S=2
．． 6) and iron were melted in a propane-acid solution and held at 1700°C for 1 hour, then the slag was discharged, and the slag and iron were added, melted and heated to 1700°C.
The operation of holding at 00°C for 1 hour was repeated 6 times.

The samples used were Example 4-1.4-2.5-1, Comparative Examples 5 and 6, and tar-impregnated unfired dolomite bricks.

The results are shown in Table 6 as the erosion index. The other values are calculated by setting the amount of corrosion loss of 850 to 4/Ci as 100.

Table 6 From Table 6 above, it has been demonstrated that the monolithic refractories according to the present invention exhibit superior corrosion resistance than the tar-impregnated unfired dolomite bricks, which are monolithic products, even though they are monolithic products.

As detailed above, the monolithic refractory of the present invention has corrosion resistance,
It has particularly excellent spalling resistance and is easy to manufacture, making it extremely valuable.

Claims (3)

[Claims] (1) The main material is a refractory material, and the refractory material has thermosetting 4
A monolithic refractory characterized by being made of a material containing 11 fats and lactams. (2) The monolithic refractory according to claim 1, characterized in that 0.5 to 80 kg of thermosetting 11 fat is used for the refractory material. (3) 0.2 to 10% by weight of lactams based on the refractory material
A monolithic refractory according to claim 1, which is used.