JPS593082A - Manufacture of refractories impregnated with surfactant or water-soluble organic matter - 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 improves a method for producing refractories by drying or firing a molded product obtained by molding a refractory material powder alone or a refractory material powder and a binder. It concerns a method of creating refractories.

In the present invention, a refractory is defined as a material that can withstand sudden changes in heat, has sufficient mechanical strength, and is resistant to erosion and deterioration of glass, molten material, solid materials, etc. that come into contact with it. This includes molds used in the precision casting industry, including shaped refractories and monolithic refractories.

Conventionally, methods for manufacturing refractories with relatively good strength include selecting and using an appropriate binder such as colloidal silica liquid, adjusting the particle size distribution of refractory material powder,
Various methods have been studied, such as adding reinforcing materials such as glass fibers and combining these methods, but each method is insufficient in terms of workability or refractory strength. Colloidal silica liquid is often used as a binder for refractories, and those with few impurities are often used for precision casting, but when only colloidal silica liquid and refractory material powder are kneaded, KFi Partial gelation of the colloidal silica liquid tends to occur due to water absorption by the refractory material, and when this occurs, uniform kneading cannot be achieved, making it difficult to obtain a refractory with sufficient strength. As for binders other than colloidal silica liquid, various binders such as ethyl silicate, phosphates, silicates, etc. are used, but these contain undesirable substances such as organic substances and alkali metals. Because of this large amount, workability during refractory production is poor, and the resulting refractories exhibit large thermal changes in strength, making quality control difficult.

On the other hand, selecting and using refractory material powders and glass fibers is difficult because the strength of the refractory varies greatly depending on the properties of the refractory material, such as its coefficient of thermal expansion, crystal shape, and particle size distribution. Obtaining certain refractories is difficult, and the work requires careful attention and management.

The present invention aims to eliminate the drawbacks of these methods of manufacturing refractories and provide a more excellent method of manufacturing refractories, which is characterized by the same characteristics that have been conventionally used in the casting industry. In the refractory production method, which consists of molding a refractory material powder alone or a refractory material powder and a binder, drying the obtained molded product, and firing it as necessary, Or to the skeleton molded product after firing,
The method consists of impregnating a colloidal silica liquid with an impregnating liquid consisting of a surfactant or a water-soluble organic substance, and drying or baking as necessary. Therefore, according to the method of the present invention, a refractory material powder or a refractory material powder and a binder are put into a suitable mixing device, water is added to adjust the moisture to an appropriate level, the mixture is kneaded, and the mixed material is molded. First, a molded article is prepared by drying and further firing if necessary. Next, #ki*≠≠The desired refractory can be manufactured by impregnating this molded product with a mixed solution of colloidal silica liquid and a surfactant or water-soluble organic substance, and then drying or baking it. .

The refractory materials used in the present invention and 11 include silicic acidic refractories such as glassy silica, crystalline silica, magnesium silicate, aluminum silicate, zirconium silicate, silicate clay, and fused silica. Examples include basic refractories such as magnesia, dolomite, and maguro, neutral refractories such as chromium oxide and chromite, and special refractories such as carbon, silicon carbide, and zirconia.

Further, as the colloidal silica liquid, one produced by any method can be used, and for example, one produced by a method such as an ion exchange method, a peptization method, or a dialysis method can be used in the present invention.

The average particle size of silica in colloidal silica liquid is 6'"~5
A range of 0 millimicrons is suitable, but especially 6 to 1 B$
It is preferable that the silica concentration be in the range of 2000m, and the silica concentration should be in the range of SIO! It is economical and convenient to have a weight of 7 to 15 e-cents or more.

'The surfactant or water-soluble organic substance mixed with the colloidal silica liquid must not cause gelation with the colloidal silica liquid. The surfactant may be an anionic or nonionic surfactant, especially anionic surfactants such as dialkyl sulfosuccinate, high alcohol, rusulfate (Na salt), and polyoxyethylene alkylphenyl. Nonionic activators such as ethers are preferred. Examples of surfactants suitable for the present invention by trade name include anionic surfactants such as L-'li:, Neocol, Perex OT, Tonmorin OT, and Cedran Hiro; examples of nonionic surfactants include Noniball B, etc. There is.

On the other hand, as the water-soluble organic substance, any organic substance that is soluble in water can be used, such as alcohols such as methylated alcohol, ethyl alcohol, ketones such as acetone and methyl ethyl ketone, methylamine, Primary amines such as amines and polyhydric alcohols such as ethylene glycol and glycerin are used. Among these, it is especially economical and convenient to use alcohols such as methyl alcohol and ethyl alcohol, and ketones such as acetone.

The mixed composition of colloidal silica liquid and the above-mentioned surfactant or water-soluble organic substance has a ratio of Sing dry weight 1゜ to surfactant weight or water-soluble organic substance weight of 100:0.5 to 3.
00:20, preferably 100:2 to Zo
It is possible to mix it so that it is within the range of o.

The impregnating ratio of the impregnating liquid into the refractory is 810% of the colloidal silica liquid. Ratio of dry weight to weight of refractory: 0.05:
A range of 100 to 1.0:Zoo is fine, but 0.
A range of 1:100 to 0.3:100 is appropriate in terms of workability and economy. Further, any impregnation method may be used for impregnating the refractory with the impregnating liquid, such as a method in which the refractory is immersed in the impregnating liquid, or a method in which the refractory is pressurized or depressurized after immersion. The molded product thus impregnated is dried or fired, if necessary, by methods well known in the industry.

Example 1 Using zircon sand and zircon flour as refractory material powder7, a cylindrical molded product was produced by pressure molding without using a binder, and after air-drying the molded product at room temperature for 48 hours, The test piece was dried at 110° C. for 20 hours and cooled in a desiccator to prepare a test piece for impregnation. The weight of this item was 75f.

8i0. Concentration: 30% by weight, Nano concentration: 0°4
2 weight/R-cent, pH 9.5, average particle size 12 mm colloidal silica liquid (trade name Cataloid-5)
The impregnating liquid of the present invention was prepared by mixing 66.2 F of I30), an anionic activator (trade name: CEDRAN) IF, and 32.2 F of water. After the above-mentioned test piece for impregnation was immersed in the impregnating liquid for 53 minutes, the weight when taken out was 81. It was Of. Thereafter, it was dried for xxotzo hours, further calcined at 900°C for 1 hour, and after cooling in a desiccator, the compressive fracture strength was measured. Strength measurement is J
The test was carried out in accordance with I8 R-2206-19155, 9, and the method of measuring the load at the time of pressure fracture. The results are shown in Table-1.

Example 2 The same colloidal silica liquid as in Example 1 66.2 f, anionic activator (trade name: Cedran) 0.012 and water 32
．． 2F was mixed to prepare an impregnating liquid PJ14.

An impregnating test piece was impregnated with this impregnating solution in the same manner as in Example 1, and then subjected to the same drying and firing treatment, and its compressive fracture strength was measured. The results are shown in Table-1.

Example 3 An impregnating liquid was prepared by mixing 33.4 f of the same colloidal silica liquid as in Example 1, an anionic activator (trade name: Cedran) IP, and 65.5 f of water. In the same manner as in Example 1, an impregnating test piece was impregnated with the impregnating solution and subjected to the same drying and firing treatment, and the compressive fracture strength was measured. The results are shown in Figure 1.

Example 4 An impregnating solution was prepared by mixing 66.2 f of the same colloidal silica liquid as in Example E, 1 f of methyl alcohol (99% purity), and 32.2 F of water. As in Example 1, this impregnating liquid was impregnated into the impregnating test 2-space, which was further subjected to the same drying and firing treatment, and the compressive fracture strength was measured.

The results are shown in Table IK.

(Additional margin) Table 1 The compressive breaking strength is the average value of three molded test pieces.

As explained above, in the refractory manufacturing process that involves drying or firing a molded product obtained by molding a refractory material powder or a refractory material powder and a binder, colloids are added to the molded product after drying or firing. silica liquid and surfactant ff1
It is known that when impregnated with an impregnating liquid consisting of lJ or water-soluble organic matter, the compressive strength is improved to 200 to 400 cm when fired at 900°C. It can be seen that the method provides an excellent method for manufacturing refractories.

Claims (1)

[Scope of Claims] 1. A method for producing a refractory, which comprises molding a refractory material powder alone or a refractory material powder and a binder, drying the resulting molded product, and firing if necessary. A method for producing a refractory, which comprises impregnating the molded product after firing or firing with an impregnating liquid consisting of a colloidal silica liquid and a surfactant or a water-soluble organic substance, and then drying or firing the same. . 2. 8 of the colloidal silica liquid contained in the above impregnating liquid.
10. A method according to claim 1, wherein the ratio of dry weight to surfactant weight or water-soluble organic matter weight is in the range of 100:0.15 to 100:20. 3. The method of claim 1, wherein the surfactant is selected from sialygyl sulfosuccinates, high alcohol sulfates, and polyoxyethylene alkylphenyl ethers. 4. The method according to claim 1, wherein the water-soluble organic substance is selected from methyl alcohol, ethyl alcohol, acetone, and methyl ethyl ketone.