JP2992211B2 - Taphole blocking material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refractory material, and more particularly to a taphole plugging material used for filling a taphole of a blast furnace to close the taphole.

[0002]

2. Description of the Related Art Tap hole plugging materials for closing tap holes in blast furnaces include, for example, refractory aggregates such as stone, chamotte, alumina, silicon carbide, and carbon. For example, a composition obtained by blending a clay component (refractory clay), a sintered material such as metallic silicon or silicon nitride, and an organic binder such as tar or phenolic resin is used.

[0003] Among the materials constituting the above composition, the clay component reacts with the blast furnace slag to produce a low melting point compound. Therefore, the tapping hole diameter tends to increase rapidly during tapping, and the tapping operation must be stopped while the hot metal and slag remain in the furnace. There is a problem that the load is increased.

Therefore, in order to solve the above problems,
Increasing the content of alumina or silica (JP-A-2-28
No. 5014) or using spinel particles (Japanese Patent Laid-Open No.
7504), a method of improving the corrosion resistance of the aggregate itself, a method of optimizing the sintering aid, and reducing the amount of clay (for example, a method of using silicon nitride iron (Japanese Patent Laid-Open No. No. 131080) has been proposed.

However, the fact is that none of these methods has sufficiently solved the above problems.

Clay not only contributes to the improvement of sinterability, but also to the slip property and shape retention of the material (tap hole plugging material) during construction. When the ratio is reduced, when the material is extruded from the filling machine and filled into the tap hole, there is a problem that the material is difficult to extrude or cannot be extruded. Cannot be performed.

An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide a tap hole plugging material which is excellent in corrosion resistance and has good filling properties and hole opening properties.

[0008]

Means for Solving the Problems In order to achieve the above-mentioned object, the present inventors have conducted various experiments and studies, and by reducing the content of the clay component to a predetermined value or less, it has been found that the present invention provides an excellent corrosion resistance. By knowing that a pig hole plugging material can be obtained, and that by adding carbon black, even if the content of the clay component is reduced, a tap hole plugging material with excellent slipperiness and shape retention can be obtained, The present invention was completed through further experiments and studies.

That is, the tapping hole plugging material of the present invention has a refractory
Combined with raw material and tar or phenolic resin
In tap hole occluder, and 3 wt% of clay component, 2
It is characterized by containing up to 20% by weight of carbon black.

[0010] In the tapping hole plugging material of the present invention, the refractory material raw materials include, for example, limestone, silicon carbide, silicon iron nitride, coke granules, graphite, clay components (refractory clay), carbon black, granules. The term refers to a refractory aggregate or a binder that constitutes a normal tap hole closing material such as pitch or tar, and does not refer to a specific type of raw material.

In the tapping hole closing material of the present invention, the corrosion resistance is improved by reducing the content of the clay component to a predetermined value or less, but the upper limit of the content of the clay component is 3% by weight.
It is. This is because the corrosion resistance is reduced when the clay component exceeds 3% by weight.

Further, the content of carbon black is from 2 to
It is preferable that the content be in the range of 20% by weight. However, if the content of carbon black is less than 2% by weight, good sliding properties and good shape retention cannot be obtained.
If the content exceeds 0% by weight, sintering of the matrix is impaired to cause weakening of the structure, thereby lowering the durability.

The particle size of carbon black is usually 20
It is preferably 0 nm or less, and it is preferable to use the tapping hole closing material of the present invention having a particle diameter of 200 nm or less from the viewpoint of ensuring good sliding properties.

[0014]

EXAMPLES Examples of the present invention will be described below together with comparative examples, and features thereof will be described in more detail.

[Preparation and Test of Sample] In order to obtain the ratios shown in Table 1, it is assumed that the composition is in the form of rock, silicon carbide, silicon iron nitride, coke granules, graphite, clay component (fire clay), carbon black, granular pitch. And the like, were mixed in a predetermined ratio, and the obtained compounded raw materials were mixed for 3 minutes, tar added to 80 ° C. was added, and then kneaded for 30 minutes. The tar was added in such an amount (standard addition amount) that the workability value when the marshall test was carried out at 40 ° C. was 600 to 650 kgf / cm ² .

[0016]

[Table 1]

In Table 1, samples A, B, C,...
Those marked with * in the column are samples outside the scope of the present invention.

[0018] Then, the obtained kneaded material was 4 MN / m
^It was press-formed into a 40 × 40 × 160 mm block at a pressure of ² . The molded body was calcined in a reducing atmosphere at 500 ° C. for 3 hours to remove volatile components, and then subjected to a corrosion resistance test and firing at 1400 ° C. for 3 hours in a reducing atmosphere.

The porosity and bending strength of the sample after firing at 1400 ° C. for 3 hours were measured. The results are shown in Table 1.

In the corrosion resistance test, pig iron and blast furnace slag were used as an erosion agent by a high frequency furnace lining method.
An erosion test at 580 ° C. × 3 h was performed. After the erosion test was completed, the sample was cut, and the area of the eroded portion was measured.
In order to evaluate the corrosion resistance of each sample, a sample A for comparison was used.
(Clay component (fire clay) without adding carbon black
Of the eroded portion of the sample having an addition amount of 10% by weight) was 1
The erosion index was determined to be 00.

FIG. 1 shows the relationship between the addition amount of the clay component and the erosion index when no carbon black was contained, and FIG. 2 shows the addition amount and the erosion loss of the carbon black when the clay component was not contained. Shows the relationship between indices. 1 and 2, the “sample” on the horizontal axis represents the sample A shown in Table 1.
ＩI indicates which sample the sample is.

Further, in order to evaluate the slipperiness, the addition amount of tar is shown in Table 1 as a standard addition amount (workability value is 600 to 6).
A marshall test was conducted at 40 ° C. to examine the change in the workability value when the amount was 50 kgf / cm ² ) and when the amount was reduced by 1% by weight from the standard addition amount. this is,
Since the slip property of the material greatly depends on the tar as the binder, in the case of a material having particularly poor slip property, the degree of increase in the workability value when the amount of the binder (tar) added is reduced is further increased. For this reason, it was considered that a material having a small degree of increase in the workability value even when the amount of the binder (tar) added was reduced can be evaluated as having a large slip property.

FIG. 3 shows the relationship between the amount of carbon black added and the workability when no clay component is added. In addition,
In FIG. 3, “Sample” on the horizontal axis represents Sample A shown in Table 1.
ＩI indicates which sample the sample is.

[Evaluation] As shown in FIG. 1, when the amount of the clay component added was set to 3% by weight or less, the erosion index was about 85% of the comparative sample A in which the amount of the clay component added was 10% by weight. It can be seen that it decreases below.

FIG. 2 shows that while the erosion index of Sample B to which carbon black was not added was about 80, the erosion index was reduced to about 70 when 2% by weight of carbon black was added. When 10% by weight of carbon black is added, the erosion index becomes 46, and carbon black becomes 20%.
It can be seen that the erosion index becomes about 44 when added by weight%.

As shown in Table 1, when carbon black was not added, the flexural strength was affected by the presence or absence of the clay component, and when no clay component was added (sample B), the flexural strength was increased. Decrease. On the other hand, when the addition amount of carbon black is more than 20% by weight and becomes 25% by weight (Sample F), the bending strength is reduced, and a problem may occur in practical use.

Further, as shown in Table 1, if the addition amount of carbon black is increased without adding the clay component, the addition amount of tar (standard addition amount) increases, so that the drying time becomes longer. Therefore, there is a problem that inconvenience occurs in operation from closing of the tap hole to opening of the tap hole.

FIG. 3 shows the relationship between the addition amount of carbon black and the workability value. From FIG. 3, when carbon black was not added, the degree of increase in the workability value when the addition amount of tar was reduced was small. It can be seen that it is large, and that the addition of carbon black can suppress an increase in the workability value when tar is reduced. That is, the addition of carbon black makes it possible to secure the slipperiness of an appropriate range of the material.

Therefore, from a comprehensive viewpoint such as corrosion resistance, workability, and mechanical strength, the content of the clay component is 3% by weight or less, and the content of the carbon black is 2 to 20%.
Most preferably, it is in the range of weight%.

[Evaluation of Actual Use] Sample A for comparison in Table 1 and Sample D according to the example of the present invention
Table 1 also shows the number of uses and the average tapping time (durable time) when was used as an actual tapping material for a blast furnace.

As shown in Table 1, with respect to the sample D of the example, tapping was performed 52 times in total, and without causing any problems regarding the filling property and the opening property, the average was 231.
Was able to perform tapping for minutes. This result is much larger than the average number of tapping times of the sample A for comparison of 24 times and the average tapping time of 178 minutes.

In the above embodiment, as the refractory aggregate,
I explained the case of using the stone, but the refractory aggregate,
The present invention is not limited to this, and various other materials such as high-purity alumina, silica, and spinel can be used. Further, the binder is not limited to tar as in the above-described embodiment, and for example, phenol resin or the like can be used. In that case, the same effect as in the above-described embodiment can be obtained. It is.

The tapping hole plugging material of the present invention is not limited to the above-described embodiment in other respects as well. The type and particle size of the refractory material, the presence or absence of the addition of other trace additives, and the like. Various applications and modifications can be made to the addition amount and the like within the scope of the invention.

[0034]

As described above, the tapping hole plugging material of the present invention comprises a mixture of a refractory material and tar or phenolic resin.
In out pig iron pore blocking material is formed by, 3% by weight or less clay component, since by containing carbon black 2-20% by weight, without impairing filling performance and open-porous, improve corrosion resistance While being able to do it, without sacrificing properties such as mechanical strength, it has excellent filling and opening properties,
In addition, it is possible to obtain a tap hole closing material having good corrosion resistance.

Therefore, by using the tapping hole plugging material of the present invention, the tapping time can be extended, and the stable operation of the blast furnace and the reduction of the labor load can be achieved.

[Brief description of the drawings]

FIG. 1 is a graph showing the relationship between the amount of clay component added and the erosion index.

FIG. 2 is a graph showing the relationship between the amount of carbon black added and the erosion index.

FIG. 3 is a diagram showing the relationship between the amount of carbon black added and workability values.

──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Yasunobu Toriya 1576 Nakahiro, Higashi-oki, Ako-shi, Hyogo 2576 Kawasaki Furnace Materials Co., Ltd. 1576-2 Kawasaki Furnace Materials Co., Ltd. (72) Inventor Makoto Nomura 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba Pref. 1 Kawasaki-cho, Chuo-ku, Kawasaki Steel Corporation Steel Development and Production Division Chiba Works (72) Inventor Tetsuro Uchida 1 Kawasaki-machi Chuo-ku Chiba City Chiba Prefecture Kawasaki Steel Corporation (56) References JP-A-4-74771 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C04B 35/66

Claims (1)

(57) [Claims] 1. A refractory material, tar or phenol resin
In out pig iron pore blocking material made by blending down, 3% by weight or less clay component, tapped hole clogging material characterized by containing carbon black of 2 to 20 wt%.