Technical field

[0001]

　The present invention relates to a blast furnace tapping hole filling mud material.

BACKGROUND

[0002]

　Blast tapping hole filling mud material (hereinafter, simply referred to as "mud material".) Is a rammed earth-like material that closes the tapping hole after tapping end at a blast furnace, using a Maddogan tap hole It is filled in. The size and the high pressure operation of recent blast furnace, the use environment of the mud material is steadily severer.

[0003]

　Characteristics required for mud material, abrasion resistance, corrosion resistance against slag and molten iron. As a technique for improving the wear resistance and corrosion resistance, the carbon raw material, silicon carbide raw material, mud material made by adding white mica are known to alumina raw materials (for example, see Patent Document 1).

CITATION

Patent Document

[0004]

Patent Document 1: Laid-Open Publication No. 1-168804

Summary of the Invention

Problems that the Invention is to Solve

[0005]

　Mad material described in Patent Document 1, those containing carbon source (graphite, coke, etc.) (60 to 80% by weight in the mud material) large amounts. However, results of the tests and study by the present inventors, mud material carbon raw material is large amount, to be inferior in wear resistance and corrosion resistance were found.

[0006]

　Further, according to Patent Document 1, muscovite is to contribute to the improvement of the reaction to the corrosion resistance of the mud material (slag resistance) and strength at high temperature range of not lower than 900 ° C. (page 2 lower right column 16 line ~ page 3 upper left column line 8), the result of test and study by the present inventors, the mud material described in Patent Document 1, although the adhesion between the tap hole (blast furnace wall) is sufficiently It not, was also found that there is a problem that the so-called hole breakage occurs.

[0007]

　Therefore, an object of the present invention is to provide, while ensuring the wear resistance and corrosion resistance required for the mud material is to provide a mud material capable of improving the adhesiveness.

Means for Solving the Problems

[0008]

　Results of the tests and study by the present inventors, it was found that to improve adhesion mud material is important to ensure sufficient expansion of the mud materials in the longitudinal center region of the tap hole. That is, the longitudinal direction the temperature of the central region 600 ~ 1000 ° C. of about tap hole (hereinafter, this temperature range is called an "intermediate temperature range".), And sufficient expansion of the mud materials in the intermediate temperature range is that it. The present inventors from this point of view is focused on the pyrophyllite as a raw material of mud material further was repeated test and study focusing on the mineral composition, the use of a pyrophyllite which contains an appropriate amount of muscovite, intermediate temperature range it has been found that can sufficiently secure the expansion of mud materials in.

[0009]

　That is, according to one aspect of the present invention, the following mud material is provided.
"A blast tapping hole filling mud material containing refractory raw material,
　in the refractory material, 50 mass over 10 mass% pyrophyllite content is 9 wt% 3 wt% or more muscovite as mineral composition % contain less,
　the content of carbon material in the refractory raw material (including 0.) 30 wt% or less in a blast furnace tapping hole filling mud material. "

The invention's effect

[0010]

　According to the present invention, while securing the wear resistance and corrosion resistance of the mud material, it can improve the adhesion.

DESCRIPTION OF THE INVENTION

[0011]

　Mad material of the present invention, in the refractory material contains less than 50 wt% to 10 wt% of pyrophyllite content is 9 wt% 3 wt% or more muscovite as mineral composition. Pyrophyllite is pyrophyllite as the main mineral composition, but containing quartz, in the present invention, from the viewpoint of a sufficient expansion of the mud materials in the intermediate temperature range as described above, muscovite (chemical composition KAl 2 (Si 3 Al) O 10 (OH) 2 using a pyrophyllite containing mineral represented by) below 3 wt% to 9 wt%. When the content of muscovite in pyrophyllite is less than 3 wt%, can not be sufficiently ensured expansion of mud materials in the intermediate temperature range, it is impossible to improve adhesion. On the other hand, when the content of muscovite in pyrophyllite is at 9 mass percent, the low melting point of muscovite (about 1250 ° C.) the corrosion resistance for the decreases. The preferred content of muscovite in pyrophyllite is at least 4 wt% 7 wt% or less.

[0012]

　The content of pyrophyllite in the refractory material is 50 wt% or less than 10 wt%. When the content of pyrophyllite in the refractory material is less than 10 wt%, it can not be sufficiently obtained adhesion improving effect pyrophyllite (muscovite). On the other hand, when the content of pyrophyllite in the refractory raw material is more than 50 wt%, the corrosion resistance is low fire resistance of pyrophyllite decreases. The preferred content of pyrophyllite in refractory raw material is 30 wt% or less than 15 wt%.

[0013]

　In mud material of the present invention, the content of carbon material in the refractory raw material (including 0.) 30 wt% or less to. When the content of the carbon material in the refractory raw material exceeds 30 mass%, the wear resistance and corrosion resistance decreases. The content of the carbon material in the refractory raw material is preferably from 15% by mass or less (including 0.), And more preferably 5 mass% or less (including 0.). Here, coke as the carbon source, graphite, although anthracite and the like, carbon black in the present invention shall be removed from the "carbon material". Carbon black is because not to lower the wear resistance.

[0014]

　During refractory raw material described above pyrophyllite, it may contain material that is used for normal mud material in addition to the carbon material. For example, alumina raw material, silicon raw material nitride, silicon carbide source material may contain carbon black, clay, or the like as appropriate. Then, adding the appropriate amount of the binder like normal mud material refractory raw material. As the binder, tar, pitch, phenolic resins and the like, its amount is preferably about 10 wt% to 20 wt% in outer percentage relative to the refractory raw material. Also, by the need to binder, for example a solvent such as Creo coat is added.
Example

[0015]

　For each example mud materials shown in Table 1, the abrasion resistance was evaluated the corrosion resistance (corrosion resistance hot metal slag) and adhesion.
　In Table 1, the "Mus content" means that the content of muscovite in pyrophyllite. "Other ingredients" and the silicon nitride raw material, silicon carbide raw material, carbon black and clays. Using the tar as "binder", it was added 15 wt% or 25 wt% in outer percentage relative to the refractory raw material.

[0016]

　Abrasion resistance, for corrosion resistance and adhesion were evaluated in the following manner, were comprehensive evaluation based on these evaluation results.

　After pressure molding mud material of each Example 7 MPa, the test piece obtained by performing the baking process of 500 ° C. heating to measure the wear amount in the method specified in JISR2252-1, Example 1 of the wear amount was determined abrasion resistance index is 100. It indicates that the abrasion resistance index is the better the wear resistance small. In Table 1, the case where wear resistance index of 120 or less ◎ (excellent), a case of 120 super 140 or less ○ (good), were expressed in the case of 140 than × and (bad).

　After pressure molding at 7MPa mud material of each example, a specimen obtained by performing baking of 500 ° C. heating, lined to a high-frequency furnace to make pig iron and blast furnace slag and erosion agent, 1550 ° C. × erosion test of 5 hours was carried out. After corrosion test, corrosion specimen dimensions (up to melting region) is measured, the melting dimensions of Example 1 was determined corrosion resistance index of 100. It indicates that the corrosion resistance index is excellent in corrosion resistance smaller. In Table 1, the case where corrosion resistance index of 120 or less ◎ (excellent), 120 ○ (good) if ultra 140 below, was expressed in the case of 140 than × and (bad).

　in the center of the carbon brick that assumes blast furnace wall provided ø50 × 50 mm through hole of, after forming a mud material of each Example Amsler into the through-hole portion, to restrain the vertical, 500 ° C. heating baking process was carried out. Then, the resulting mixture was fired in 1000 ° C. × 3 h the intermediate temperature range assumed in a reducing atmosphere, after firing, the adhesive strength was measured mud material at room temperature. During measurement of the adhesion strength was measured for adhesive strength so as to hollow out the mud materials in the carbon brick by Amsler. In Table 1, the adhesive strength ◎ (excellent) in the case of more than 2.5 MPa, the ○ (good) if less than above 1 MPa 2.5 MPa, and notation of less than 1 MPa × (the poor).

　wear resistance, corrosion resistance and evaluation of all adhesion ◎ the case of (excellent) ◎ (excellent), ◎ has evaluation (excellent) or ○ (good), there is no evaluation of × (bad) the case ○ (good), was a case in which there is an evaluation of × (bad) × (the poor).

[0017]

[Table 1]

[0018]

　As shown in Table 1, Examples 1 to 9 that are within the scope of the present invention, comprehensive evaluation is ◎ (excellent) or ○ (good), good results were obtained. That is, the content of pyrophyllite and carbon material in the refractory raw material, and the content of muscovite in pyrophyllite With within the scope of the present invention, while securing the wear resistance and corrosion resistance of the mud material, the adhesive it was confirmed that it is possible to improve. The content of pyrophyllite and carbon material in the refractory raw material, and Examples 1,7,8,9 content of muscovite in pyrophyllite is within the preferred range, overall evaluation is ◎ (excellent), It was particularly good.

[0019]

　In contrast, Comparative Example 1 in the example containing a small amount of pyrophyllite in refractory raw material, the adhesion decreases.
　Comparative Example 2 In the example content of pyrophyllite are often in the refractory raw material, the corrosion resistance is lowered.
　Comparative Example 3 is an example containing a small amount of muscovite in pyrophyllite, adhesion was reduced.
　Comparative Example 4 is an example high content of muscovite in pyrophyllite, corrosion resistance is lowered.
　Comparative Example 5 is an example containing large amount of carbon material in the refractory raw material, the wear resistance is lowered. In addition, because high content of carbon material in the refractory raw material, the amount of binder is increased, because the structure of the mud material becomes coarse, the corrosion resistance is lowered.

The scope of the claims

[Requested item 1]

　A blast furnace tapping hole filling mud material containing refractory raw material,
　in the refractory material, a pyrophyllite content of muscovite is 9 wt% 3 wt% or more as a mineral composition 10 wt% to 50 wt% contained the following,
　the content of carbon material in the refractory raw material (including 0.) 30 wt% or less blast furnace tapping hole filling mud material is.

[Requested item 2]

　Blast tapping hole filling mud material according to claim 1, wherein the content of said muscovite in the pyrophyllite is 7 wt% or less than 4 wt%.

[Requested item 3]

　The refractory in the raw material, blast furnace tapping hole filling mud material according to claim 1 or 2 containing the pyrophyllite than 15 wt% to 30 wt%.

[Requested item 4]

　The carbon raw material content is 15 wt% or less (including 0.) Blast furnace tapping hole filling mud material according to any one of claims 1 to 3 which is in the refractory raw material.