JPH0765087B2 - Blast furnace tap hole closing method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for closing a tap hole of a blast furnace.

Conventional technology and its problems When closing the tap hole of the conventional blast furnace, one kind of mud material is press-fitted into the tap hole with a mud gun, and the mud material is dried by the heat in the furnace to form a burning mud. Has been adopted. The firing mud is opened by using a drill, an oxygen lance or the like and tapping is performed.

Mud materials satisfying the following conditions are required for the work of closing and opening the tap holes in the blast furnace operation.

(A) The curing time is short, that is, the time required for blockage is short.

(B) The ability to press fit into the tap hole with a mud gun is good.

(C) Opening work after firing is easy.

(D) Excellent corrosion resistance to hot metal and molten slag, and little increase in tap hole diameter.

Here, the conditions (a) and (c) and the condition (d) are contradictory. That is, in order to satisfy (a), it is necessary to use a material having good air permeability and / or thermal conductivity. If (c) is to be satisfied, a material with low strength is preferable when using the drilling hole method, and
A material having good thermal conductivity and being easily melted is desired. On the other hand, in order to satisfy (d), it is preferable that the material is a high-strength and dense material and has excellent heat resistance. However, at present, no mud material satisfying such conflicting conditions has been obtained.

Means for Solving the Problems The present inventor has conducted research in view of the above problems of the prior art, and a method for filling mud materials of two or more different materials into tapholes, that is, shown in FIG. As described above, the mud gun (5) is packed with the rapid hardening mud material (1) and the conventional mud material (3) in layers in the axial direction of the mud gun, and this is filled with the piston (7).
The inventor invented a method of press-fitting into the taphole and applied for a patent (Japanese Patent Laid-Open No. 60-103105). The present inventor has conducted extensive studies to further improve the above method and further simplify the work of closing and opening a taphole. In the process, in order to investigate the temperature change of the mud material filled in the taphole, as a result of actual measurement and computer simulation, the taphole (9) became a trumpet shape in the furnace direction as shown in Fig. 2. , Therefore, the unsintered part (1
7) occurred, and it was discovered that the presence of this unsintered part (17) causes troubles such as gas discharge at the time of opening and abnormal melting damage due to insufficient sintering. The present inventor has further studied a method of using a mud material having excellent sinterability in order to eliminate the unsintered portion, and as a result, as shown in FIG. Mud materials of different materials for holes (21)
And (23) are concentrically layered and filled, and 2) the central mud material (23) is made excellent in drying property, thermal conductivity and openness, and the peripheral mud material (21). By having excellent strength and slag resistance (corrosion resistance), it is possible to significantly simplify the work of closing and opening the taphole, and prevent the rapid expansion of the taphole diameter during tapping. Found and completed the present invention.

That is, the present invention is characterized in that, when closing a blast furnace tap hole with a mud material, the blast furnace tap hole is filled with two or more different kinds of mud materials in a concentric form in a multilayered manner. Related to the blockage method.

In the present invention, two or more different types of mud materials are used.

When filling in a concentric multilayer form, the mud material used in the central portion has high thermal conductivity, and any material having excellent dryability, curability, sinterability, etc. can be used.
Examples of the main component include those containing iron oxide and / or iron powder, those containing chrome ore, and the like. These mud materials may contain, as components other than the above, refractory aggregates, refractory clay, binders and the like that are commonly used for mud materials. The blending amount of each of the above components is not particularly limited and may be appropriately selected and used. The particle size is not particularly limited and may be appropriately selected, but normally a particle size of about 5 to 0.01 mm is used. The mud material has low fire resistance and can be easily opened by using an oxygen lance. In addition, among the above mat materials, the mud material containing iron oxide as the main component has a thermal conductivity of 10 Kcal / h · ° C (500 ° C) or higher. Therefore, due to the high thermal conductivity property, the temperature rises quickly and the overall hardening It has excellent properties, dryness and sinterability.

As the mud material used for the peripheral portion when filling in multiple layers in a concentric circle shape, any material having excellent strength and corrosion resistance can be used, and as the main component, for example, bauxite, bansoil shale, fused alumina And the like, and those containing a siliceous raw material. These mud materials may contain, as components other than the above, refractory aggregates, refractory clay, binders and the like that are commonly used for mud materials. The blending amount of each of the above components is not particularly limited and may be appropriately selected and used. The particle size is not particularly limited and may be appropriately selected, but is usually 5 to 0.
Use about 01mm.

The mud materials of different materials described above are filled in the tapholes of the blast furnace as described below, for example. That is, the above two types of mud materials may be concentrically layered and packed in a mud gun in accordance with a usual method, and the mud materials may be press-fitted into the taphole. At this time, it should be noted that the plastic viscosities of the above two kinds of mud materials are set to the same level. If not the same,
Even if the tap hole is filled with the mud material which is concentrically multi-layered and packed in the mud material gun, a desired structure, that is, a concentric and multi-layered structure is not formed in the tap hole. The plastic viscosity of the mud material is not particularly limited and may be appropriately selected. Further, in adjusting the lower plastic viscosity of the mud material, any ordinary method can be adopted, and examples thereof include a method of adjusting the addition amount of the binder. Thus, in the mud material filled in the concentric multilayer form, the central portion thereof is made of a material having excellent sinterability, and therefore, the entire mud material is uniformly fired, and an unfired portion is not generated. Absent.

In the present invention, as shown in FIG. 4, the mud material (2
It is also possible to use a highly air-permeable mud material (25) filled in the center of 3) with emphasis on air permeability, and as shown in Fig. 5, a mud material having excellent filling properties together with the peripheral mud material (21). (2
7) may be filled in layers so that the filling property is emphasized.
As the highly breathable mud material (25) and the highly filling mud material (27), any ordinary material can be used.

Effects of the Invention The blast furnace taphole closing method of the present invention exhibits the following excellent effects.

a) Due to the multi-layered mud material for filling the tapholes in the blast furnace, the porosity, corrosion resistance, and blockability are significantly improved, and stabilization of the blast furnace operation and labor saving are achieved. Further, since the work of opening the fired mud material is easy, the amount of drills, oxygen lances and the like used is significantly reduced, and the time required for the work of opening holes is further shortened.

b) Since the mud material around the taphole has excellent corrosion resistance, the diameter of the taphole is small and the taphole can be tapped for a long time and the number of times of blockage per day can be reduced.

C) The mud material around the taphole is excellent in drying property and sinterability. Therefore, due to insufficient drying of the mud material, there are problems such as live blowing at the time of opening and rapid expansion of taphole diameter during tapping. Is prevented.

Examples The following examples and comparative examples will further clarify the present invention.

Example 1 The respective raw materials were mixed in the compounding ratio (parts by weight) shown in Table 1 to produce a central mud material and a peripheral mud material used in the method of the present invention. The viscosity coefficient of these two mud materials is 20 kg
It was s / m ² (60 ° C.). The thermal conductivity of the central mud material was 15 Kcal / h · ° C (500 ° C). Obtained 2
The seed mud material was concentrically multi-layered and packed in a mud gun, which was press-fitted into a blast furnace tap hole and fired, and then the tap hole was opened by an oxygen lance for tapping. The results are shown in Table 2.

Comparative Example 1 Raw materials were mixed at the compounding ratio shown in Table 1 to produce a conventional mud material (silica material). Its thermal conductivity is 4.5Kcal /
It was h ° C (500 ° C). The obtained mud material was used in Example 1.
A blast furnace taphole was filled with the same mud gun as above and baked, and then a hole was opened by a drill for tapping. The results are shown in Table 2.

It is clear from Table 2 that the method of the present invention (Example 1) shortens the opening time and extends the tapping time as compared with the conventional method (Comparative Example 1). It can be seen that the method significantly improves the corrosion resistance of the taphole.

[Brief description of drawings]

FIG. 1 is a schematic diagram in the case where a plurality of mud materials are layeredly filled in the axial direction of the mud gun, and FIG. 2 is a schematic diagram in the case where the mud material is press-fitted into the tap hole of the blast furnace using the mud gun. FIG. 3 is a schematic view in the case where mud materials of two different materials are concentrically multi-layered and filled in the taphole in the present invention, and FIGS. 4 and 5 show the present invention. An embodiment is shown. (1) …… Rapid hardening mud material (3) …… Conventional mud material (5) …… Mad gun (7) …… Piston (9) …… Blast furnace tap hole (11) …… Blast furnace tap hole outer wall ( 13) …… Inner wall of blast furnace taphole (15) …… Iron ore + coke (17) …… Unsintered part (19) …… Depth gutter (21) …… High corrosion resistance mud material (23) …… High heat Conductive mud material (25) …… Highly breathable mud material (27) …… Highly filled mud material

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tatsuo Kawakami 2 at 1576, Higashioki, Oki, Nakako, Ako-shi, Hyogo 2 Kawasaki Furnace Co., Ltd. (56) Bibliography 48-64404

Claims (1)

[Claims] 1. When closing a taphole of a blast furnace with a mud material,
A method for closing a tap hole of a blast furnace, comprising filling the tap hole of the blast furnace with mud materials of two or more different materials in concentric layers.