JPS5945968A - Manufacture of non-baked brick for electric furnace ceiling - 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 method for manufacturing unfired bricks used for large ceilings of electric furnaces.

The bricks used for the lids, or ceilings, of electric furnaces for steelmaking are made from the slag of the electric furnace, which has a high melting point due to the presence of salt and salt (in both acidic and acidic conditions, the melting point is high due to the high temperature, high temperature and common chemical components. Silica brick has generally been widely used as a material that does not deteriorate rapidly.

In addition, with the adoption of the oxygen steel manufacturing method and the manufacture of special steel, higher temperature work is required, which increases the wear and tear of ceiling bricks.In recent years, high alumina bricks have also been widely used for this purpose. .

These are used effectively as bricks for large ceilings, but both have their advantages and disadvantages and are not completely satisfactory. is desired.

For example, silica bricks (11 large ceiling bricks) have the necessary lightness and high temperature strength to a certain degree, but they do not have the required strength in recent years as mentioned above. Heat resistance under severe high temperature conditions, especially at high temperatures of 1650℃ or higher, and j6! However, there are some drawbacks when it comes to sex.

Furthermore, although high alumina bricks have excellent heat resistance and corrosion resistance, they have the disadvantage of being large in weight.

In view of these points, the present invention was developed in order to find the optimal brick for the large ceiling of an electric furnace, which can be made lightweight without compromising high-temperature heat resistance and corrosion resistance, depending on its use and operating conditions. Furthermore, it has a large and appropriate residual expansion coefficient at an operating temperature suitable for use as a ceiling structure, and can prevent loosening and drooping phenomena as a ceiling structure.

That is, the present invention uses A1203-Sin, system raw material 90-5
An unfired brick for large ceilings in an electric furnace, characterized in that a refractory raw material made by blending quartzite in a ratio of 10 to 50 times with an appropriate amount of a room-temperature binder, molded, and then dried. The gist is the manufacturing method.

In this way, the refractory raw material used in the present invention is A1203-
These are 5i02-based raw materials and quartzite, and other components must not be blended or must be kept as small as possible.

The Al2O3-5i02-based raw material used here is an aluminous Al2O3-5i02-based raw material in which the Al2O3 component is greater than the Sin component, and the ratio of both is Al2O3' 9 [1, -50'fi, 5
1 o 21 o - 5 degrees, AI, 03-1-5 in 20 twill, 90% or more. Specifically, bauxilite, sillimanite, kyanite, and andaliusite.

Suitable materials include Tyasboa shale and synthetic mullite.

In general, this Al2O3-8i02-based raw material is
The particle size is adjusted to coarse, medium and fine particles and becomes the main raw material for the brick of the present invention.

Next, it is effective to use quartzite with a 5102 component of 96 or more since it is not necessary to use it, and it is preferable to mix it in a relatively coarse particle size. That is, the object of the present invention can be easily achieved by using particles of 50 or more meshes larger than 6 meshes, particularly particles in the range of 6 to 20 meshes.

The blending amount of quartzite with respect to the Al4O1-5iCh type raw material is 10 to 50 quartzite in the total amount of both, and the balance is 0A120! -8102 type raw materials need to be 90 to 50 inches. This has a high proportion of quartzite.
In this case, the heat resistance in particular decreases, and the reaction with the slag is likely to proceed.
This is because it poses a problem in terms of service life, and on the other hand, if it is too small, weight reduction cannot be achieved. This is because the amount of residual expansion due to mullite formation is reduced.

The present invention is to obtain unfired bricks made of these refractory raw materials, and a room-temperature binder is used.

Suitable binders are clay, phosphoric acid, or phosphoric acid-based materials, preferably a combination of both. Al2O,-8i
The amount is 5 to 20 parts per 100 parts of the raw material consisting of O2-based raw materials and quartzite, and the preferred use of phosphoric acid or phosphate is 1 to 5 parts.

In addition, it aluminum phosphate is suitable as a phosphate.

Does the present invention cover these? It is dried after molding according to the usual procedure, and the drying temperature is usually 300 to 40.
Approximately 0°C is appropriate.

In this way, the present invention can provide a brick that is suitable for large ceilings of electric furnaces, which has heat resistance, corrosion resistance, high strength, light catchability, and has a large residual expansion coefficient. The practical value is great.

Example The raw material composition of each sample was adjusted as shown below.
After press molding under the pressure of “IJ 00 Kylotr”4
Dry at 00℃ for 5 hours.
Shown in the table.

Sample A (method of the present invention): Outer soil shale (Al2O.

88 honors, 1310. 4%, OaOα 3
Quartzite (Sin□94%
, A120B CL 7%, OaO2,5%, ?
e20B 2.0%)! A mixture of 10 parts (80 pieces or more in the range of 6 to 20 meshes), 10 parts of clay, and 6 parts of phosphoric acid.

○Sample B (conventional law; high alumina brick)...Tamajukan rock (A120388%, Sin, 4%, 0a0
15%, Fe20j2.5chi) 6-20 Metsuyu 4
1゜○Sample C (conventional method 1, Silica brick)...Quartzite (5in2
94 fi, Al2O3CL 7%, OaO2,5
%.

Fe20j2.0%) f6~20 Methushura 4
0 mltt part, 20 mesh or less, 25 direct lid part, 15
A mixture of less than 0 methane in the ratio of 65 to 4 inguinal parts and 3 to 3 parts of lime milk.

Table 1 Sample A ('ne IB Sample (+Chemical analysis (+
ti(9)) Si02 35.8 10,9 9
4. OA'1203Sa7 8i5 u
7Fez 03 1.9 1.8
2.00aOO,80,12,5 Others 2.8 5.7 [1
, 8 Physical properties Apparent porosity (φ) 22,6 17.6
2611 Hirohiro 2,24 2. B4
1.8 [1 appearance ratio beast 2.90 5.45
234 Compressive strength (Kglol) 266
876 206 Softening point under load (℃) 'I', 144 [114001575
T2 1b22 1460 151T
a 1645 165[116
02 heating change rate book) 1560℃ x 8 hours +50 +2.4
01660℃×8 hours +2.9 -1-
1.7 +0.4 Corrosion resistance (w) 5.1
4.2 1['L5* Corrosion resistance was measured using electric furnace slag at 1650℃ x 10 hrs using the crucible method.
This is the measured value of the cut amount of the slag line after the erosion test.

These samples were used as large ceiling bricks for a 50-ton class basic slag w1 furnace, and the results were as follows.

Furnace cover total 11Kg) A 9700 B, 11700 G 7600 Operation results A...Durable life is 150 heats, smooth surface, poor wear of silica brick, high A 1. The bealling phenomenon of the osseous bricks was small, and both characteristics were exhibited.

B: Durability is 150 heats, and the beering phenomenon is large.

C: Durability is 120 h-1, and bath loss is large.

Claims (1)

[Claims] 1. Al, O, -8i02-based raw material 90 to 50i [1
Manufacture of unfired bricks for large ceilings in an electric furnace characterized by mixing 1% quartzite with 10 to 5011Nt% of quartzite together with an appropriate amount of a room-temperature binder, molding, and drying. Law. 2. The manufacturing method according to claim 1, wherein 50 normal f% or more of quartzite is blended as relatively coarse particles with a particle size of 6 to 20 mesh. 5. Claim 1, in which the room-temperature binder is clay and/or phosphoric acid (salt). ! 1 or the method for producing item 2, item 1. 4. The production method according to any one of paragraphs 1 to 5, wherein the clay is blended in 5 to 20 vertical parts per 1 part of the refractory raw material consisting of Al, 03-5i02 raw materials, and quartzite. . 5. The manufacturing method according to any one of claims M1 to 4, wherein phosphoric acid or phosphate is used in an amount of 1 to 5'@U parts per 1 part by weight of 100 weight raw materials.