JP2006219330A - Monolithic refractory for spray repairing and repairing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a monolithic refractory for a spray repairing capable of preventing the peeling and falling in the spray repairing application of the monolithic refractory. <P>SOLUTION: In the monolithic refractory for the spray repairing wherein an expansible component is added to the monolithic refractory containing refractory aggregate, a refractory powder, a binder, a dispersant and a quick setting agent, a linear changing rate of +0.5 to +2.0% is imparted to the monolithic refractory by adding the expansible component when heated to 1,500°C after the spray repairing and cooled to the room temperature. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an indeterminate refractory material for spray repair that can prevent peeling and falling off, and a repair method, and particularly relates to an indeterminate refractory material for spray repair suitable for repair for a blast furnace.

  Conventionally, the lining of the blast furnace pit (hereinafter referred to as the blast furnace pit) is generally constructed of an irregular refractory material, and various irregular refractory materials are known as the lining material. It is offered to.

  A blast furnace lining lined with such an irregular refractory material is often damaged by use or partially broken, so that repair is often required. In such a case, the repair is usually performed by spraying an irregular refractory material on the repaired portion of the blast furnace pit and attaching the repaired refractory material to the lining of the blast furnace pit. In other words, the irregular refractory material for repair applied to the repaired part of the blast furnace slag adheres to the reaction with the lining material of the blast furnace slag, the unevenness or rough surface of the lining, and its wedge effect, and this makes it Can also adhere to the surface.

  However, there is a problem that the irregular refractory material for repair sprayed on the repair part peels off from the blast furnace lining after repair. The reason for this peeling off is that, for example, the irregular refractory material sprayed on the repaired part adheres due to the reaction and wedge effect immediately after spraying, but for example, it is accompanied by repeated taping work that reaches about 1500 ° C. Thermal deformation caused by heating and cooling occurs, and if the rate of change in the irregularity of the irregular refractory material for repair during this cooling is small, even if it is negative or positive, cracking in the reaction area or irregular refractory material for repair This is considered to be because the wedge effect is reduced or eliminated due to the shrinkage of the blast furnace, and the adhesion force to the lining of the blast furnace iron is weakened. And since the linear change rate of the irregular refractory material changes depending on the number of repetitions of heating and cooling and tends to become smaller as the number of times increases, even if there is no problem at first, peeling or Dropping often occurs.

  Such peeling and dropping of the repair material during repair is a major problem, particularly in the repair of blast furnace flaws, but it is not unique to the repair of blast furnace flaws, and an irregular refractory material is sprayed onto the vertical repair surface. It is a phenomenon that occurs in common with repairs to be performed, and there is a strong need for improvement.

  On the other hand, by adding residual expansion to the refractory material for the blast furnace lining, it is exposed to high-temperature hot metal and slag, preventing the occurrence of cracks in the lining that is repeatedly heated and cooled. It has been known. The amorphous refractory material disclosed in Patent Document 1 is an example.

This amorphous refractory material is made of an amorphous refractory material for blast furnaces containing alumina refractory material, silicon carbide, carbon refractory material, etc., to add silica stone and steel fiber to give residual expansion. The residual expansibility prevents cracking due to heat shrinkage. However, such an irregular refractory material is generally intended to prevent cracks generated in the lining of the blast furnace shell, and therefore generally has a low residual expansibility, and is completely different from prevention of peeling and falling off during repair of the lining.
JP-A-5-70248

  An object of the present invention is to provide an irregular refractory material for spray repair that can prevent peeling and dropout in the above-described spray repair construction of the irregular refractory material.

  In order to achieve the above-mentioned problems, the present inventor has intensively studied the repairing irregular refractory material, and as a result, by giving a linear change rate of a predetermined size to the repairing irregular refractory material, For example, when repairing irregular refractory material is sprayed onto the repaired part of the blast furnace lining, the wedge effect between the repaired part of the lining and the irregular refractory material for repairing is maintained to maintain the adhesion between them. Thus, the present inventors have found that the repairing irregular refractory material can be prevented from being peeled off and dropped off, and the present invention has been achieved.

That is, the present invention provides an irregular refractory material for spray repair and a repair method described below.
(1) An expansive component was added to an unfixed refractory material for repair including refractory aggregate, refractory powder, binder, dispersant and quick setting agent, and spray repair work was performed on the refractory material. An irregular refractory material for spray repair, which is provided with a linear change rate of +0.5 to + 2.0% when the irregular refractory material is heated to 1500 ° C. and then returned to room temperature.
(2) The inflatable component contains at least one selected from the group consisting of quartzite, quartz sand, wax, kyanite, sillimanite and andalusite, for spray repair of (1) above Unshaped refractory material.
(3) The explosive component is contained in an amount of 2 to 40% by mass with respect to 100% by mass of the irregular refractory material for spray repair. Standard refractory material.
(4) The unfixed refractory material for spray repair of (1), (2) or (3) above, wherein the unfixed refractory material for spray repair is a repair material for blast furnace dredging.
(5) Spraying, characterized in that construction water is added to the irregular refractory material for spray repair described in any of (1) to (4) above, and spray repair is performed on the repaired part of the structure. Repair method using irregular refractory material for repair.

  The present invention provides an irregular refractory material for spray repair with a linear change rate of +0.5 to + 2.0% when the irregular refractory material subjected to spray repair is heated to 1500 ° C. and then returned to room temperature. By maintaining the wedge effect of the non-uniform refractory material for spray repair on the repaired part and maintaining the adhesive force, it is possible to prevent the non-uniform refractory material that has been spray repaired from being detached and dropped for a long period of time. It is excellent as an irregular refractory material for blast furnace lining repair.

Hereinafter, the present invention will be described in more detail.
The powdered amorphous refractory material in the spray construction method of the present invention generally has an expandable component added to the main components such as refractory aggregate, refractory powder, binder, dispersant and quick setting agent. Become. As the main component of the irregular refractory material for spray repair in the present invention, a conventional non-uniform refractory material for spraying construction and an irregular refractory material for spray repair can be used as appropriate. However, it is not limited to these.

  Here, the refractory aggregate includes alumina, bauxite, diaspore, mullite, kyanite, van earth shale, chamotte, quartzite, pyrophyllite, sillimanite, andalusite, chromite, spinel, magnesia, zirconia, zircon, chromia. One or more selected from carbon such as silicon nitride, aluminum nitride, silicon carbide, boron carbide and graphite, titanium boride and zirconium boride are preferable. In this specification, the refractory aggregate refers to those having an average particle diameter exceeding 30 μm. These refractory aggregates preferably have an average particle diameter of 12 mm or less, particularly 10 mm or less. Two or more types of particle sizes, for example, a combination of coarse particles, medium particles, and fine particles can be used. In this case, 95% by mass or more of the particles is the maximum particle diameter / inner diameter of the transfer tube in relation to the inner diameter of the transfer tube. The ratio is preferably 1/7 to 1/3.

  Further, the refractory powder forms a joint for joining the refractory aggregate by filling the gaps of the refractory aggregate, and is preferably a refractory ultrafine powder having an average particle diameter of 10 μm or less, preferably 5 μm or less. used. As the refractory ultrafine powder, alumina, fumed silica and the like are preferable. Alumina and fumed silica may be used in the form of not only powder but also a part of alumina sol, silica sol, colloidal silica and the like. The refractory powder is preferably contained in an amount of 30 to 60 parts by mass, particularly 40 to 50 parts by mass with respect to 100 parts by mass of the refractory aggregate.

  As the refractory powder, in addition to the above refractory ultrafine powder, other materials having an average particle diameter of preferably 30 μm or less can be added although the particle size is larger than that of the refractory ultrafine powder. Such materials include alumina, titania, bauxite, diaspore, mullite, van earth shale, chamotte, pyrophyllite, sillimanite, andalusite, quartzite, chromite, spinel, magnesia, zirconia, zircon, chromia, silicon nitride, nitriding It is preferable to use carbon such as aluminum, silicon carbide, boron carbide, titanium boride, zirconium boride, and graphite, bentonite, or silica alone or in combination. However, the irregular refractory material in the present invention is a clayey material whose viscosity rapidly increases when moisture is added, such as contained in the conventional dry construction method refractory material, for example, refractory clay, Kaolin, bentonite, etc. are preferably reduced as much as possible, and preferably 3 parts by mass or less with respect to 100 parts by mass of the refractory aggregate.

  The binder contained in the amorphous refractory material functions as a binder for the amorphous refractory. Preferably, alumina cement is used. When alumina cement is used as a binder, the repair part of the structure can maintain strength over a wide range from room temperature to high temperature. Examples of binders that can be used include phosphates such as phosphoric acid and aluminum phosphate, lignin sulfonates, and water-soluble phenols. The binder is preferably contained in an amount of 2.5 to 20 parts by mass, particularly 5 to 12 parts by mass with respect to 100 parts by mass of the refractory aggregate.

  In the present invention, the dispersant contained in the amorphous refractory material is important. When the dispersant is not contained, the viscosity increases when construction water is added to the powdered composition, and the transport pipe is blocked. There is a risk that. Dispersants include condensed phosphates such as sodium tetrapolyphosphate and sodium hexametaphosphate, carboxylates such as polycarboxylates and polyacrylates, sulfones such as melamine sulfonate, and β-naphthalene sulfonate. One or more selected from acid salts are preferred. The dispersant is preferably added in an amount of 0.03 to 1.5 parts by mass, particularly 0.08 to 0.35 parts by mass, with respect to 100 parts by mass of the refractory aggregate.

Furthermore, the quick-setting agent contained in the amorphous refractory material includes silicates such as sodium silicate and potassium silicate, aluminates such as sodium aluminate, potassium aluminate and calcium aluminate, sodium carbonate, potassium carbonate, carbonates such as sodium hydrogen carbonate, sodium sulfate, potassium sulfate, sulfates such as magnesium _{sulfate, CaO · Al 2 O 3,} 12CaO · 7Al 2 O 3, CaO · 2Al 2 O 3, 3CaO · Al 2 O 3, 3CaO _{· 3Al 2 O 3 · CaF 2} , calcium aluminate such as _{11CaO · 7Al 2 O 3 · CaF} 2 , or calcium oxide, calcium hydroxide, calcium salts such as calcium chloride at least one member selected from, is preferably used The

  Among the quick setting agents, it is preferable to use sodium aluminate because it is easily available, is inexpensive, and has excellent characteristics. Since sodium aluminate has a high melting point, it does not lower the fire resistance of the refractory and does not impair the properties of the refractory. The quick setting agent may also serve as a binder. For example, silicate edges such as sodium silicate and potassium silicate may be employed as the quick setting agent and the binder.

  These quick setting agents need to be contained in an amorphous refractory material in a powder form, and the average particle diameter is preferably 20 to 200 μm, particularly 50 to 100 μm. The content of the quick setting agent varies to some extent depending on the type of the quick setting agent, but is preferably 0.07 to 4.5 parts by weight, particularly 0.7 to 2.2. 5 parts by mass is preferred. If the amount is less than 0.07 parts by mass, the rapid setting speed may be insufficient even if water is added, and the refractory applied by spraying may flow down. Therefore, there is a possibility that the spraying construction becomes difficult, and the performance as a refractory such as heat resistance and corrosion resistance is lowered.

  The present invention is to add an inflatable component to the main component of the above-mentioned irregular refractory material for spray repair, and to impart a predetermined linear change rate (residual expansibility) to the irregular refractory material for repair. Features. If the repaired irregular refractory material has the desired residual expansibility, the repaired irregular refractory material will not be appropriate for the repaired part of the structure even if it is repeatedly heated and cooled by operation after spraying the repaired irregular refractory material. A rust effect occurs, and the adhesion with the construct can be increased and sustained. For this reason, for example, even if it has a vertical repair surface such as a blast furnace flaw, by adding a residual expansibility of a certain size to the unfixed refractory material for repair, It is possible to prevent the refractory material from peeling or dropping off.

  As the magnitude of the linear change rate applied to the irregular refractory material for spray repair, it is +0.5 to + 2.0%, preferably +1 to + 1.5% when returned to room temperature after firing at 1500 ° C. . If the linear change rate is less than + 0.5%, the wedge effect is small, and sufficient adhesion to the repaired part of the structure cannot be obtained. Therefore, the sprayed repaired irregular refractory material can be satisfactorily prevented from peeling off or falling off. It becomes impossible. On the other hand, if the linear change rate exceeds + 2.0%, it is not preferable because peeling or dropping occurs due to the spraying material protruding. Note that the linear change rate is defined after firing at 1500 ° C., assuming an upper limit temperature of the use temperature of the amorphous refractory material, which is the target.

  The residual expansibility in such a repairable irregular refractory material is obtained by adding an expansive component to the main component of the repairable irregular refractory material as described above. Specifically, for example, expansive siliceous minerals and sillimanite group minerals are added to the repairable amorphous refractory material as an expansive component. It can be obtained by a method such as mineral change due to or adjustment of the material particle size composition including the matrix portion. In particular, the method of adding an expansive siliceous mineral or sillimanite group mineral to an amorphous refractory material is economical and excellent in terms of work. Siliceous minerals such as silica, silica sand, and wax stones, and silimanite group minerals such as silimanite, kyanite, and andalusite can be preferably used. Of these, kyanite and andalusite are residual swelling effects and corrosion resistance. And preferred from an economic point of view. These expansible components can be appropriately selected and used depending on the use of the non-fixed refractory material for repair, the type of main component, and the like, and may be used alone or in combination.

  In the present invention, the expansible component is preferably contained in an amount of 2 to 40% by mass, more preferably 7 to 13% by mass, with respect to 100% by mass of the irregular refractory material for spray repair. The content of the inflatable component mainly varies depending on the type of the inflatable component and the use of the irregular refractory material for spray repair, and is not strictly limited. However, within the above range, the linear change rate is +0. It can be easily adjusted to a range of 5 to + 2.0%.

  FIG. 1 is a partial cross-sectional view of a repaired part of a blast furnace slag which is a typical embodiment of the present invention, where (a) is before repair and (b) is after repair. Hereinafter, although the repair method of a blast furnace flaw is demonstrated with reference to FIG. 1, FIG. 1 is illustrated in order to make an understanding of the method of this invention easy, and the method of this invention is not limited to this.

  In FIG. 1, reference numeral 1 denotes a blast furnace slag permanent tension, and reference numeral 2 denotes a lining (saddle base material) formed of an irregular refractory material on the inner surface of the blast furnace slag permanent tension 1. The lining 2 that is exposed to high-temperature hot metal or slag and is repeatedly heated and cooled is damaged by prolonged use. In order to continue using the blast furnace slag, it is necessary to appropriately repair the damage generated in the lining 2 as the repair portion 3.

  The repair portion 3 shown in FIG. 1A is roughly divided into a metal line 3 ′ and a slag line 3 ″. In particular, local damage of the metal line 3 ′ often limits the life span. Since the 3 ′ cross-sectional shape is a wedge shape, repairing the same part can provide an excellent repair effect and can significantly increase the life of the cocoon.

  In the present invention, construction water is added to an irregular refractory material for spray repair to which an inflatable component is added, and the repair portion 3 of the lining 2 is sprayed and repaired. The spraying of the irregular shaped refractory material for repair can be performed by, for example, a general-purpose spraying device for the amorphous refractory material or a small spraying device thereof.

  The repairable irregular refractory material 4 sprayed on the repair portion 3 enters the concave portion of the repair portion 3 and comes into close contact with the lining 2. Next, when dried and baked, it hardens in a state where it enters the concave portion of the repair portion 3 and generates a wedge effect on the concave portion of the repair portion 3. This wedge effect is due to the residual expansibility obtained by the function of the expansible component added to the repairable refractory material 4. As a result, the repairable irregular refractory material 4 of the repair section 3 can be held on the lining 2 of the blast furnace heel permanent tension 1 with a large adhesive force. Can be prevented from peeling off or falling off from the inner lining 2 of the steel sheet. And since this wedge effect is maintained even in the repeated use of a blast furnace, the said peeling and dropping can be prevented stably.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not construed as being limited by the examples.

Example 1
The ratio shown in Table 2 with respect to 100% by mass of the repaired amorphous refractory material as an inflatable component that imparts residual expansibility to the spray-fixed amorphous refractory material having the composition shown in Table 1. Six kinds of amorphous refractory materials were prepared including those with no addition and (mass%). A panel of 400 (vertical) x 400 (horizontal) x 100 (thickness) mm was produced by spraying each prepared irregular refractory material at room temperature, and a JIS test piece (40 x 40 x 100 mm) was produced from the panel. Two pieces were cut out, and the two test pieces were fired at 1300 ° C. and 1500 ° C. for 3 hours, respectively, in accordance with JIS R2554, returned to room temperature, and the linear change rate (%) of each test piece was measured. Here, the reason why the linear change rate (%) after firing at 1300 ° C. was measured is to see how the linear change rate changes depending on the temperature as a reference. These measurement results are shown in Table 2. Examples 3 to 5 are examples, and examples 1, 2 and 6 are comparative examples.

(Example 2)
Six kinds of amorphous refractory materials prepared in Example 1 were used for the lining at a position of about 3 to 8 m from the outlet of an actual blast furnace pit (inner width: about 1 m × length: about 15 m) toward the downstream of the pit. The repaired part was sprayed and passed through, and after 5000 tons, the blast furnace was inspected and the state of occurrence of peeling / dropping off of each of the irregular refractory materials sprayed was examined. Further, in order to accurately grasp the degree of peeling / dropping, the residual area ratio (%) of each irregular refractory material was measured by (area after passing / area before passing × 100). These results are shown in Table 2.

  From Table 2, in the case of the irregular refractory materials of Example 1 and Example 2 where the expansion component is not added or the amount added is small and the linear change rate after firing at 1500 ° C. is smaller than + 0.5% It can be seen that peeling or dropping occurs, and that the amount of expandable component added increases as in Example 6, and dropping occurs even when the linear change rate after firing at 1500 ° C. is greater than + 2.0%. .

  In the present invention, as described above, an inflatable component is added to the irregular refractory material for spray repair, and the desired residual expansibility is imparted, thereby removing or dropping off the irregular refractory material in the repair portion. Since it can be prevented, it can be widely applied to irregular refractory materials for spray repair. In particular, it is suitable for an irregular refractory material for spray repair for blast furnace.

BRIEF DESCRIPTION OF THE DRAWINGS It is a fragmentary sectional view of the repair part of the blast furnace iron which is typical embodiment of this invention, (a) shows the state after repair before (a).

Explanation of symbols

1: Permanent blast furnace lining 2: Lining 3: Repair part 3 ': Metal line 3 ": Slag line 4: Unfixed refractory material for repair

Claims (5)

  An indefinite form of fire-resistant material that is inflated by adding an inflatable component to an indefinite form of fire-resistant material for repair, including fire-resistant aggregate, fire-resistant powder, binder, dispersant, and quick setting agent. An irregular refractory material for spray repair, characterized by providing a linear change rate of +0.5 to + 2.0% when the material is heated to 1500 ° C. and then returned to room temperature.   The inflatable component for spray repair according to claim 1, wherein the expansive component contains at least one member selected from the group consisting of quartzite, quartz sand, wax, kyanite, sillimanite, and andalusite. Refractory material.   3. The non-uniform refractory material for spray repair according to claim 1 or 2, wherein 2 to 40% by mass of an expandable component is contained with respect to 100% by mass of the non-uniform refractory material for spray repair.   The irregular refractory material for spray repair according to claim 1, wherein the irregular refractory material for spray repair is a repair material for blast furnace.   An irregular refractory for spray repair, characterized in that construction water is added to the irregular refractory material for spray repair according to any one of claims 1 to 4 and spray repair work is performed on a repair portion of the structure. Repair method using materials.

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