JPH0240025B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to a mat material for blast furnace tapholes. Conventional technology and its problems Traditionally, wax materials for blast furnace tapholes include waxite,
Refractory aggregates such as siyamoto, alumina, carbon silicon, etc.
Sintering agents such as fireclay and iron silicon nitride, and binders such as tar are used. When this matwood material is press-filled into the taphole with a matudo gun and heated by the heat in the furnace, the volatile components in the tar evaporate and the residual carbon binds the refractory aggregate, fireclay, and sintering agent. (carbon bond), a fired mat is formed. Tapping and slag are
A taphole is opened in this fired mat. However, as blast furnaces have become larger in size and operating conditions have become more severe in recent years, it has been desired to further improve the strength and slag resistance of the wood. In other words, when conventional pine wood is used in a larger blast furnace, the tap hole will rapidly wear out and expand during tapping and slag tapping, and a large amount of furnace gas will leak from the enlarged tap hole. , the tapping ends with hot metal and slag remaining in the furnace. This results in a significant decrease in workability. To solve the above-mentioned problems, a wood material containing clay, alumina shimoz, carbon, silicon carbide, tar, and a specific silicon alloy has been proposed (Japanese Patent Publication No. 47252/1983). This is due to the reaction between metallic silicon and CO gas, which is oxidized carbon contained in tar (3Si + 2CO → 2β-SiC + SiO ₂ ).
Silicon carbide (2β-
This method takes advantage of the production of SiC) and SiO ₂ , which maintains the density of the structure. However, the dispersibility of the silicon alloy in the mat material is not sufficient, and the durability of the mat material in an actual furnace is not satisfactory. Means for Solving the Problems As a result of extensive research in view of the problems of the prior art as described above, the present inventors have developed a method using a specific tar pitch for blast furnace taphole mat material made of fire-resistant aggregate and fire-resistant clay. The authors discovered that by adding a silicon alloy coated with a silicon alloy, the dispersibility of the silicon alloy in the mat material was significantly improved, and a mat material for blast furnace tapholes with excellent strength and slag resistance could be obtained. Completed the invention. That is, the present invention provides (a) 100 parts by weight of a raw material for blast furnace taphole material consisting of refractory aggregate and fireclay, (b) 15 to 25 parts by weight of a volatile organic carbon compound, and (c) softening point
This invention relates to a mat material for blast furnace tapholes containing 0.3 to 2 parts by weight (in terms of metal silicon content) of a silicon alloy with a metal silicon content of 75% or more, the surface of which is coated with tar pitch at 120°C or higher. In the present invention, as a raw material for matud material for blast furnace tapholes,
Use refractory aggregate and fireclay. As refractory aggregates, those normally used for matudo materials can be used, such as high alumina raw materials such as fused alumina and sintered alumina, acidic raw materials such as waxite and clay shamotzu, and carbon such as coke and graphite. Raw materials include silicon carbide, silicon nitride, silicon iron nitride, etc., and at least one of these is used in the present invention. The particle size of the refractory aggregate is not particularly limited;
You can choose as appropriate, but for example, 5-1mm is 10-30mm.
%, 1-0.1mm is 10-30%, 0.1mm or less is 20-50%
You can use it by adjusting it so that it becomes . As the fireclay, those normally used for pine wood can be used, such as kaolin, sericite,
Examples include Kibushi clay, Frogme clay, and bentonite. The blending amount of fireproof aggregate and fireclay is not particularly limited and may be selected as appropriate, but for example, fireproof aggregate 80~
It may be about 95% by weight, and about 5 to 20% by weight of fireclay. As the volatile organic carbon compound serving as the binder for the raw material for the matud material for the blast furnace taphole, those normally used for the matud material can be used, such as coal tar, tall oil, phenolic resin, furan resin, etc. can. The blending amount of the volatile organic carbon compound is preferably about 15 to 25 parts by weight based on 100 parts by weight of the raw material for the blast furnace taphole. If it is less than 15 parts by weight, the workability during press-fitting into the tap hole is poor, while if it exceeds 25 parts by weight, the wood becomes porous due to an increase in volatile components and its durability is reduced. In the present invention, as a silicon alloy, the metal silicon content is 75%.
% or more. Specific examples of silicon alloys include metal silicon, ferrosilicon, and the like. Metallic silicon content is 75%
It is not preferable to use a silicon alloy with a content of less than 10%, since metals other than metallic silicon and impurities contained in the silicon alloy will increase, and these will reduce the strength of the mat material of the present invention. Also, as tar pitch, one with a softening point of 120°C or higher is used. When coating a silicon alloy with tar pitch, add 100 parts of tar pitch to 100 parts by weight of silicon alloy.
It is sufficient to add about 400 parts by weight and knead well. If the amount of tar pitch is less than 100 parts by weight, it will not be possible to sufficiently cover the silicon alloy, and no improvement in strength will be observed. On the other hand, if it exceeds 400 parts by weight, the amount of metallic silicon will be insufficient and the strength will not be improved satisfactorily. The grain size of the tarpitch-coated silicon alloy thus obtained is preferably about 1 mm or less. If it exceeds 1 mm, dispersibility deteriorates and sufficient strength cannot be improved. The blending amount of the tar pit-coated silicon alloy is preferably about 0.3 to 2 parts by weight in terms of metallic silicon content, based on 100 parts by weight of the raw material for the mat material for blast furnace tapholes.
If it is less than 0.3 parts by weight, the effect of improving strength will be small, while if it exceeds 2 parts by weight, the viscosity of the wood material will increase, which is not preferable. The pine wood of the present invention is produced by kneading predetermined amounts of each of the above raw materials. Effects of the Invention In the present invention, by coating the silicon alloy with tar pitch, the dispersibility of the silicon alloy in the mat material is significantly improved, and a mat material for blast furnace tapholes with excellent strength and slag resistance can be produced. Obtainable. Examples Examples and comparative examples are given below to further clarify the present invention. Examples 1 and 2 Raw materials were mixed in the proportions (parts by weight) shown in Table 1 to produce blast furnace taphole mat material of the present invention. The obtained pine wood of the present invention was subjected to a performance test. The results are shown in Table 2. As the tar pitch-coated silicon alloy, metallic silicon with a metallic silicon content of 95% and a tar pitch/silicon alloy ratio of 300/100 was used. Comparative Examples 1 to 4 Each raw material was mixed in the proportions (parts by weight) shown in Table 1 to produce comparative products (Comparative Examples 1 and 2) and conventional pine wood (Comparative Examples 3 and 4). Comparative products are those in which the amount of tarpitch-coated silicon alloy (same as the example) is greater or less than the predetermined amount. The various pine materials obtained were subjected to the same performance tests as in the examples. The results are shown in Table 2. Incidentally, the silicon alloy used was the same as in the example in which the tar pitch was not coated.

【table】

[Table] Table 2 shows that (1) the wood material of the present invention has superior strength and slag resistance than conventional products (Comparative Examples 3 and 4), and (2) the amount of tar pitch-coated silicon alloy It can be seen that there is almost no improvement in strength and slag resistance unless it is within the predetermined range of the present invention. When the tap material of the present invention was filled into a tap hole, the diameter of the tap hole did not expand much during tapping, and the tap time was extended. As a result, the amount of wood used and the labor load were reduced, furnace conditions continued to be favorable, and productivity improved significantly.

Claims (1)

[Claims] 1. (a) 100 parts by weight of the raw materials for blast furnace taphole wood consisting of refractory aggregate and fireclay, (b) 15 to 25 parts by weight of volatile organic carbon compounds, and (c) 100 parts by weight of raw material for blast furnace taphole wood consisting of refractory aggregate and fireclay, (c) 100 parts by weight of a raw material for blast furnace taphole wood consisting of refractory aggregate and fireclay, (b) 15 to 25 parts by weight of a volatile organic carbon compound, and (c) a tar pit with a softening point of 120°C or higher. A mat material for blast furnace tapholes containing 0.3 to 2 parts by weight (in terms of metallic silicon content) of a silicon alloy whose surface is coated with a metallic silicon content of 75% or more.