JPH1036177A - Blocking material for tapping port of blast furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a blocking material for a tapping port of a blast furnace excellent in improvement of operation environment from closure of tapping port of the blast furnace to opening hole and slag resistance and having high durability by using a carbon black raw material hardly having oil absorption amount of dibutyl phthalate(DBP) and carrying out reduction of addition amount of a binder while keeping proper packing property. SOLUTION: This blocking material for a tapping port of a blast furnace comprises 100 pts.wt. powder part composed of 5-25wt.% carbonaceous raw material excluding carbon black raw material, 5-50wt.% silicon carbide, 10-45wt.% silicon nitride-based raw material, 2-15wt.% carbon black having <=100(ml/100g) oil absorption amount of dibutyl phthalate and 15-75wt.% refractory raw material and a carbon-containing binder in an amount of 10-25 pts.wt. based on outer percentage.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a blast furnace taphole plugging material.

[0002]

2. Description of the Related Art With the recent increase in size and pressure of blast furnaces, the use conditions of blast furnace taphole plugging materials have become severe.
The properties required for taphole plugging materials in blast furnaces are also severe, and three particularly important properties are as follows: During construction, when the taphole can be easily filled with a mud gun It has extrudability and good openability at the time of tap hole opening; After filling the blast furnace tap hole plugging material, the blast furnace tap hole plugging material sinters in a short time, Withstands slag abrasion damage; Withstands chemical erosion by hot metal and slag during use, has no increase in tap hole diameter, and has corrosion resistance that enables stable tapping for a long time.

[0003] Among these properties, the wear resistance and corrosion resistance to hot metal and slag are particularly important. Various blast furnace tap hole plugging materials with improved properties have already been disclosed. For example, JP-A-2-285014 discloses that
Using an alumina raw material having an alumina content of 80% or more as a main raw material, 0.5 to 4 parts by weight of graphite having a particle size of 44 μm or less, 15 to 30 parts by weight of silicon nitride having a particle size of 44 μm or less, and kaolin clay 5 to 15 parts A mud material (clogging material) for a blast furnace taphole is disclosed, in which a residual carbon organic compound is added to and kneaded with a weight part and the remaining refractory material.

Japanese Unexamined Patent Publication (Kokai) No. 3-205377 discloses that as a material for imparting the hole-opening property of a mud material, 3 mm to 0.1 m such as quartz grains, quartz grains, quartz sand, siliceous brass grains, and kyanite sand are used.
A mud material for a blast furnace taphole is disclosed, wherein one or more kinds of a mixture of high expansion materials composed of m particles are added in an amount of 5 to 50% by weight.

Further, Japanese Patent Publication No. 7-110793 discloses (a)
60 to 84% by weight of carbon material, 5 to 15% by weight of silicon carbide,
Carbon black 4-15% by weight, metallic silicon 2-8% by weight and Al ₂ O ₃ -SiO ₂ -based refractory aggregate occluder material 100 parts by weight and consisting of 5 to 20 wt% (b) a liquid organic binder 15 Blast furnace taphole plugs containing ~ 26 parts by weight are disclosed.

JP-A-8-119754 discloses a tap hole closing material characterized by containing a clay component of 3% by weight or less and carbon black of 2 to 20% by weight. .

[0007]

In the blast furnace tapping plugging material as described above, the durability is improved by using a large amount of highly durable raw materials. It is necessary to increase the addition amount of the material and the binder, which may increase the time required for firing or hinder sintering. In addition, it is not possible to sufficiently dissipate gas due to volatile components present in the binder to the outside world, and there is a danger that the retained gas will be ejected when the taphole is opened. Furthermore, when the amount of the binder added is increased, the amount of gas generated due to volatile components present in the binder increases,
Defects such as an increase in the number of cracks inside the taphole, coarsening of the structure, and a problem in durability occurred, which was not preferable, and the effect of the highly durable raw material could not be fully utilized.

However, due to the recent increase in the size of the blast furnace and the severer operating conditions, the load on the blast furnace tap hole plugging material has become extremely high. In terms of economics, the unit consumption has been reduced,
It is desired to extend the tapping time, that is, to improve the corrosion resistance, by saving labor in the working environment. In contrast, the conventional blast furnace taphole plugging material as described above has insufficient durability,
Extension of tapping time was not fully satisfactory.

[0009] Accordingly, an object of the present invention is to use a carbon black raw material having a low oil absorption of dibutyl phthalate (DBP) and reduce the amount of binder added while maintaining proper filling properties, thereby improving the blast furnace discharge. An object of the present invention is to provide a high-durability blast furnace tap hole plugging material which is excellent in slag resistance due to improvement of a drilling work environment from a plug hole blockage.

[0010]

The present inventors have conducted various studies on the addition amounts of various carbon black raw materials having different DBP oil absorptions. As a result, while maintaining the proper filling property of the blast furnace taphole plugging material, They have found that the amount of binder added can be reduced and have completed the present invention.

More specifically, the plug material for a blast furnace taphole of the present invention comprises 5 to 25% by weight of carbonaceous material excluding carbon black material, 5 to 50% by weight of silicon carbide, 10 to 45% by weight of silicon nitride-based material, and DBP oil absorption. 2 to 15% by weight of a carbon black raw material having an amount of 100 (ml / 100 g) or less and a refractory raw material of 15 to 7%
100 parts by weight of powder consisting of 5% by weight
It is characterized by containing 25 parts by weight of a carbon-containing binder.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the blast furnace tapping plugging material of the present invention will be described in detail. Conventionally, it has been practiced to add a carbon black raw material to a fine powder portion of a blast furnace taphole plugging material as a plasticizer, a binder and a corrosion-resistant material. In this case, the conventional carbon black has a high oil absorption and the amount of the binder added is generally large. As a result, the time required for sintering becomes longer, sintering is hindered, and gas is not sufficiently diffused to the outside world. In addition, the amount of gas generated due to the volatile components in the binder increases, cracks inside the taphole increase, and other defects and roughening of the structure occur.

Therefore, the carbon black raw material used in the present invention has a DBP oil absorption of 100 (ml / 100 g) or less, preferably 80 (ml / 100 g) or less, and a DBP oil absorption of 100 (ml / 100 g). One or more of the following carbon black raw materials can be used.
DBP oil absorption of carbon black raw material is 100 (ml /
If the amount is larger than 100 g), the amount of the binder added increases, and the slag resistance decreases, which is not preferable. Here, any carbon black raw material may be used as long as the DBP oil absorption is within the above range, and for example, channel black, furnace black, acetylene black and the like can be used. The particle size of the carbon black raw material is not particularly limited and can be appropriately selected.
It is preferred to use: If the particle size of the carbon black raw material exceeds 75 μm, plasticity suitable for filling may not be obtained. The amount of the carbon black raw material is in the range of 2 to 15% by weight, preferably 4 to 12% by weight. Carbon black raw material addition amount is 2
If the amount is less than 15% by weight, the effect of reducing the amount of the binder is insufficient, and if the amount is more than 15% by weight, the effect of reducing the amount of the binder is insufficient.

Next, as the carbonaceous raw material used for the powder portion of the blast furnace taphole plugging material of the present invention, any ordinary carbonaceous raw material except carbon black raw material can be used.
For example, graphite, coke, coal powder and the like can be mentioned. The addition amount of this carbonaceous raw material is in the range of 5 to 25% by weight, preferably 8 to 22% by weight. Here, if the addition amount of the carbonaceous raw material is less than 5% by weight, good porosity and corrosion resistance cannot be imparted to the blast furnace taphole plugging material.
If it exceeds 5% by weight, it is not preferable because sufficient strength relating to wear resistance cannot be obtained.

Next, the silicon carbide used for the powder portion of the blast furnace taphole plugging material of the present invention is not particularly limited, and any conventional silicon carbide can be used. The addition amount of silicon carbide is 5 to 50% by weight, preferably 10 to 4%.
It is in the range of 5% by weight. 5% by weight of silicon carbide
If it is less than 30, sufficient corrosion resistance and abrasion resistance cannot be imparted to the blast furnace tap hole plugging material, and the addition amount is 50% by weight.
If it exceeds 300, the sinterability of the silicon carbide itself is low, so that the strength at high temperatures is reduced, and the corrosion resistance and wear resistance of the silicon carbide cannot be sufficiently exhibited.

Next, the silicon nitride-based raw material used for the powder portion of the blast furnace taphole plugging material of the present invention is not particularly limited. For example, silicon nitride or silicon nitride may be used. it can. The addition amount of the silicon nitride-based raw material is in the range of 10 to 45% by weight, preferably 12 to 43% by weight. If the addition amount of the silicon nitride-based material is less than 10% by weight, sufficient corrosion resistance and wear resistance cannot be imparted to the blast furnace taphole plugging material, and the addition amount of the silicon nitride-based material is 45% by weight. %
If it exceeds, the strength is reduced and the corrosion resistance and the wear resistance cannot be sufficiently exhibited.

Next, as the clay raw material used in the powder portion of the blast furnace taphole plugging material of the present invention, it is preferable to use plastic clay, such as Kibushi clay and ball clay. it can. Addition amount of clay raw material is 3 ~ 15
%, Preferably in the range of 5 to 13% by weight. If the amount of the clay raw material is less than 3% by weight, the plasticity is poor and satisfactory extrusion filling properties cannot be obtained, and if it is more than 15% by weight, the corrosion resistance is undesirably reduced.

Next, other refractory raw materials that can be used in the powder portion of the blast furnace taphole plugging material of the present invention include, for example, alumina,
Mullite, spinel, zircon, zirconia, raw stone,
Oxide raw materials such as magnesia can be used, and one or more of these can be used. The refractory raw material can be used in an amount of 15 to 75% by weight depending on the amount of the carbon black raw material, carbonaceous raw material, silicon carbide raw material, silicon nitride raw material and clay raw material.

The blast furnace tap hole plugging material of the present invention has a carbon-containing binder of 10 to 25 parts by weight, preferably 12 to 23 parts by weight, based on 100 parts by weight of the powder having the above mixing ratio. Is contained. Here, as the carbon-containing binder, for example, petroleum or coal tar, novolak-type phenol resin, or a mixture thereof can be used. If the added amount of the carbon-containing binder is less than 10 parts by weight, it is not preferable because good filling properties cannot be obtained, and if it exceeds 25 parts by weight, the volatile matter contained in the carbon-containing binder increases. Therefore, it is not preferable because cracks, a decrease in strength and a decrease in corrosion resistance due to an increase in the number of pores may occur in the structure of the blast furnace tap hole closing material during the temperature rise period after the tap hole blockage.

The blast furnace taphole plugging material of the present invention is characterized by its raw material composition as described above, and the method of preparing and applying the blast furnace taphole plugging material is not particularly limited. Any method can be used.

[0021]

The blast furnace taphole plug material of the present invention will be further described below with reference to examples and comparative examples. Examples Table 1 below shows the mixing ratio of the blast furnace taphole plugging material of the present invention and the comparative product, and the slag resistance of the obtained blast furnace taphole plugging material.

[0022]

[Table 1]

In Table 1, the erosion index was determined by a rotary drum erosion test using a blast furnace slag under a reducing atmosphere at 1500 to 15%.
The average amount of erosion after the test at 50 ° C. for 4 hours was measured, and the result was indicated by an index with the comparative product as 100. The apparent porosity and compressive strength were measured on a sample after firing at 1350 ° C. for 3 hours. The specimen was 50 mmφ.
It has a shape of × 50 mm and a molding pressure of 50 kg /
It was created in cm ² . Further, the workability index is 4
A marshall test is performed at 5 ° C., and the result is shown as an index with the comparative product 1 as 100.

[0024]

As is apparent from the above description, the plug material for a blast furnace taphole of the present invention can reduce the amount of the carbon-containing binder added without impairing the workability, and has high durability. Things.

Claims (1)

[Claims] 1. A carbonaceous raw material excluding a carbon black raw material of 5 to 25% by weight, silicon carbide of 5 to 50% by weight, a silicon nitride-based raw material of 10 to 45% by weight, and a dibutyl phthalate (DBP) oil absorption of 100 (ml / 100 g) or less, wherein 100 parts by weight of a powder portion comprising 2 to 15% by weight of a carbon black raw material and 15 to 75% by weight of a refractory raw material contain 10 to 25 parts by weight of a carbon-containing binder in an outer case. Blast furnace tap hole plugging material.