JPS6096580A - Sealing material for blast furnace tap hole - 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 plugging material for a melting furnace tap such as a blast furnace tap or an electric furnace tap, a so-called mud material.

Currently, the melting furnace outlet plugging materials include chamotte, mullite, alumina, silicon carbide, and graphite.
A glaze and a pJ plastic material or binder such as sericite, tar, phenol resin, or molasses are added and kneaded.

However, although clay and sericite are used to provide extrusion plasticity during filling operations and to sinter the mud material after plugging, the amount used is typically 15 to 20% by weight relative to the refractory aggregate. % has been reached. However, as the amount added increases, there are problems such as an increase in the shrinkage of the mud material and a decrease in corrosion resistance. In addition, tar, which has been used as a binding material in the past, emits significant smoke when burned, and since the sintering time is long, the time required to hold the crimping with a mud gun is long, resulting in pollution and work-related problems.

In addition, when liquid phenolic resin is used instead of tar, the curing reaction starts at a relatively low temperature and quickly hardens when the temperature exceeds 1000, so the plasticity value of the plugging material increases, especially in the summer. There are also problems in terms of workability and workability, such as poor extrusion workability, and plugging materials using phenolic resin as a binder generate highly toxic gases such as formaldehyde when heated. Furthermore, simply using molasses instead of tar or liquid phenolic resin does not improve the increased shrinkage and decreased corrosion resistance.

The present invention has been made to solve the drawbacks of these conventional plugging materials, and includes one or more of chamotte, mullite, alumina, silicon carbide, graphite, and other refractory bone materials, as well as crepe sand and molasses as the material or binder. It is an object of the present invention to provide a melting furnace outlet plugging material with good workability, which is characterized in that powder pitch and/or phenol resin powder is further added and kneaded as necessary.

Next, the present invention will be explained in detail.

As the refractory bone material, it is generally possible to use a mud material. In particular, it is effective to use silicon carbide in the form of fine powder because it has low wettability with hot metal or molten steel and is highly corrosion resistant. Further, other refractory bones 4A include block materials used as lining materials in blast furnace factories, etc., or materials obtained by pulverizing waste materials such as tap trough materials.

Crepe sand is approximately 50% quartz and 30% kaolinite.
It is a clay mineral produced as a mixed mineral with a composition of 20% illite, and has a fire resistance of about 30 on the Segel cone. The particle size is approximately the same as that of normal viscosity, about 2 μm or less. Crepe sand can increase the sintering strength of the occluder. Furthermore, since the sintering shrinkage is less than that of general clay containing a large amount of J-olinite or selinite, the plugging material containing this has less sintering shrinkage. Therefore, there is an advantage that no pores, cracks, etc. are generated in the plugging material, and safety is increased. Crepe sand can increase the sintering strength by adding a small amount during the blending of the plugging material, and the amount used is about 5 to 15 weight Ij 1%.

If it is less than 5% by weight, the sintering of the plugging material will be insufficient, and if it is more than 15% by weight, the corrosion resistance of the plugging material will decrease.

Molasses is a byproduct of the sugar manufacturing industry that is obtained in the molasses process of producing raw material paste from sugar cane, sugar beet, etc. It usually contains sugar, protein and some I11, which are mainly composed of sucrose and its derivatives. It consists of a mixture of ash and water, and its normal state is a syrupy, viscous liquid. In the plugging material using this material, the carbohydrates and proteins that are the components of molasses are carbonized and sintered, giving it a bonding strength, but the hardening by heating is 1 degree slower than tar and slower than phenolic resin. Therefore, it is sintered earlier than in the case of tar to the extent that it can cope with the increase in the number of times of tapping.
In addition, unlike phenol resin, it does not harden during work, so the work burden of cleaning and removing hardened mud gun deposits is reduced. The plugging material using molasses has excellent plasticity, so it has good extrusion workability, and the viscosity of molasses does not change much due to temperature, and it does not change over time during storage, so the plugging material using this can be used for a long time in a high-temperature workplace. It also has the advantage that it can be used for a long time without any problem. Furthermore, considering the composition of molasses, it is thought that no harmful substances such as tar or phenolic resin are generated by itself or during heating, so there is no problem in terms of environmental hygiene. Molasses is 1
Use 5-25 weight 1t1%.

Powder pitch and phenolic resin powder are in powder form at room temperature, and at high temperatures, they soften and melt and then carbonize.

Since they are insoluble in water but in powder form, they can be handled like refractory aggregates during kneading and can therefore be well dispersed with molasses. Pitch and phenol resin have a high carcass ratio, so even if they are added in small amounts, a plugging material with high sintering strength can be obtained. It is thought that the sintering of the plugging material is carried out while the molasses, powdered pitch, and phenolic resin powder have different curing initiation temperatures and curing times.

The powder pitch preferably has a softening point of 90 to 25001, a particle size of 125 μm or less, and a carbon residue rate of 45% or more. The amount used is 1-7% by weight, preferably 2-5% by weight. If it is less than 1% by weight, the sintering strength of the plugging material is insufficient, and if it is more than 7% by weight, it is unfavorable in terms of environmental hygiene as well as the problem of tar fumes.

The powdered phenolic resin used is a 7-polack type having a softening point of 80 to 130'o. This powdered 7-el resin is usually one that does not contain a curing agent such as hexamine. However, a small amount of hexazine or the like may be added if necessary. Unlike pitch, phenolic resin is slightly hygroscopic, but it is almost insoluble in water, so it can be handled in the same way as refractory aggregate during kneading, similar to pitch. The amount of phenolic resin used is 1-7% by weight, preferably 2-5% by weight. If it is less than 1% by weight, the effect of improving the sintering strength of the plugging material is small, and if it is more than 7% by weight, it is not only unfavorable in terms of environmental hygiene, but also economically expensive, similar to the problem of tar fumes.

Next, an example will be described.

Table 1 shows the formulations and properties of Examples of the present invention.

A1--'l (z 4 shows an example of the present invention, A5 shows a conventional tarbot using tar as a binder phase in a refractory aggregate as a comparative example.

As is clear from Table 1, the crystal muds 1 to 4 of the present invention had almost the same extrusion plasticity values as the comparative example m5 (2(1
The extrusion plasticity value at 'L+ is lower for the product of the present invention. )
, extrusion workability is good. Also, (5(l l)'
The product of the present invention, AI-1164, is superior to the comparative example in terms of hot strength at O and 1.2 (1 (l) C, and is sintered quickly and with high strength.

Figure 1 is a curve diagram showing the relationship between temperature and plasticity for Inventive Product 2 and Comparative Example A5, and Figure 2 shows the relationship between storage days and plasticity for Inventive Product 1 (h2 and Comparative Example A5). In the curve diagram (storage and plasticity value measurement warm cucumber, 2()c), as shown in Figure 1, the product of the present invention has suitable extrusion ii) plasticity, and as shown in Figure 2, this plasticity is long-term. Even when stored, there is little change.

'1 The inventive product and the sample of Comparative Example A5 were each heated to 600C.
L rollers and non-exploding ψI products 1F = 1 to &2 samples were placed in a laboratory furnace held at
The smoke started in 1 minute and stopped after about 25 minutes, whereas in Comparative Example &5, the smoke started in about 5 to 8 minutes after being added.
It continued until () minutes later, and the amount of smoke produced was also the same as that of the product of the present invention, JIG, l.
- It was about 1 () times that of A4.

In addition, as a result of using the product A1 of the present invention for blocking the blast furnace taphole with a mud gun, the extrusion work was similar to that of the conventional tarboter.
It can be opened with a mud gun by 11 guns, and the amount of smoke produced during use is less than that of a tarbot, and even when opening FJK, it can be opened easily with an opening machine as with conventional tarbots.

As mentioned above, the occluder according to the present invention has appropriate extrusion plasticity, and this ufgii property does not change much even during long-term storage, and the sintering of the occluder after occluded is completed in a short time, resulting in natural It has a sintering strength that does not cause cracks, and has good opening properties, and is resistant to corrosion by hot metal, molten steel, and slag.Erosion loss during tapping progresses almost uniformly, and It has advantages such as good adhesion to sprue bricks, and as mentioned above, it emits less smoke and no harmful gases, and even if this material gets on your skin or clothes, it can be easily washed away. It has excellent features such as:

In Table 1, the extrusion plasticity value indicates the quality of extrusion workability, and the lower the plasticity value, the lower the resistance to the extrusion force. The measurement was carried out using a small-sized human. In addition, in the same table, the hot compressive strength test specimen is a kneaded product/tranmer l.
(Hardened 20 times, 50 mm ψ x 59 mm) It was made into a J-shaped piece with a thick H. The compact was heated in a reducing atmosphere at the temperature indicated in the table for X hours, and the compressive strength of the hot specimen was measured. I+ 450'OX 2hrs The physical properties after firing are as follows: The molded product was fired in a reducing atmosphere,
Measurement was performed after cooling.

[Brief explanation of the drawing]

Figure 1 is a curve diagram showing the relationship between temperature and plasticity for Examples &2 and Comparative Example &5 of the present invention, and Figure 2 is a curve diagram showing the relationship between the number of days kept and the plasticity of unexploded DHI62 and Comparative Example 11 (h5). It is a curve diagram. Fig. 1 2f+ 4 (l fin ) lfl wetness (C) C Fig. 2 fl In 2n: (0 Storage 1-1 number (+1)

Claims (1)

[Scope of Claims] (]) One or more types of refractory aggregates such as chamotte, mullite, alumina, silicon carbide, graphite, and other refractory aggregates with a plasticizer or a bond 4
A melting furnace tap plugging material, characterized in that crepe sand and molasses are added as 'A' and kneaded. (2) The melting furnace tap L according to claim 1, characterized in that powder pitch and/or powder resin is further added as the plasticizer or binder and kneaded.
Occlusion material.