JP2019137607A - Monolithic refractory composition - Google Patents

Abstract

To provide a monolithic refractory composition that can ensure the same adhesive property, hardenability or the like even when not using conventional rapid hardening agents such as sodium aluminate, has safety and good long-term storage property, and can be applied by easy operation.SOLUTION: A monolithic refractory composition contains a fireproof aggregate, a fireproof powder, a binding agent, and a dispersant as essential components. In the monolithic refractory composition, the dispersant includes a phosphoric acid-based dispersant. In addition, the monolithic refractory composition contains bentonite and a lithium salt.SELECTED DRAWING: None

Description

  The present invention relates to an amorphous refractory composition, and more particularly to an amorphous refractory composition that can be constructed without blending a conventionally used quick setting agent such as sodium aluminate.

  The amorphous refractory is a refractory that is formed by on-site construction, but alumina cement is generally blended as a hardener to develop hardening. Alumina cement has a high heat resistance among cements, but has a lower heat resistance than other refractory aggregates. Therefore, the content of alumina cement is reduced, and a very small amount of alumina powder is passed through a small amount of alumina cement. A low-cement type refractory that promotes agglomeration is also known (see, for example, Patent Document 1).

  In order to spray such an irregular refractory, a quick setting agent such as sodium aluminate is usually blended as an essential component, and this quick setting agent is previously added (internally added) to the composition. In some cases (for example, see Patent Document 2), and in some cases (external addition) immediately before spraying (see, for example, Patent Document 3).

JP 11-199334 A JP 2002-213880 A JP 2002-220288 A

  By the way, when a quick setting agent is internally added as in Patent Document 2, a change in properties is caused thereby, so that sprayability during construction is reduced, and accordingly, adhesion is reduced and rebound loss is increased. End up. In this case, since the properties change as described above, the long-term storage properties also deteriorate.

  On the other hand, in order to ensure long-term storage, it is effective to add a quick setting agent just before construction as in Patent Document 3, and the deterioration of characteristics as in the case of internal addition described above does not occur. In order to obtain a predetermined composition at the time of construction, dedicated equipment is required. Therefore, the dedicated equipment must also be carried and installed at the construction site, and a space for that is required. Furthermore, in the construction operation, the step of adding a quick setting agent is required, so that the construction operation becomes complicated.

  In addition, sodium aluminate, which is a quick setting agent that is often used in the past, is a strong alkali and needs attention in handling. Therefore, it is also required to use components that are safer and easier to handle in construction work.

  Therefore, the present invention solves the above-mentioned problems, and can secure the same adhesion, curability, etc. without using a conventional quick setting agent, has good long-term storage, and is easy to construct. An object is to provide an amorphous refractory composition that can be carried out by simple operation.

  The amorphous refractory composition of the present invention is an amorphous refractory composition comprising refractory aggregate, refractory powder, a binder, and a dispersant as essential components, wherein the dispersant is a phosphate-based composition. It contains a dispersant and further contains bentonite and a lithium salt.

  According to the amorphous refractory composition of the present invention, an amorphous refractory can be formed while ensuring equivalent adhesion, curability and the like without using a quick setting agent such as sodium aluminate. In addition, this irregular refractory composition is safe, has long-term storage stability, and can be easily constructed.

It is explanatory drawing of the airflow conveyance type spray construction method using the amorphous refractory composition which is one Embodiment of this invention.

  Hereinafter, the present invention will be described in detail with reference to embodiments.

[Amorphous refractory composition]
As described above, the amorphous refractory composition of the present embodiment includes a refractory aggregate, a refractory powder, a binder, a dispersant, bentonite, and a lithium salt.

(Fireproof aggregate)
The refractory aggregate used here is a main component for forming an amorphous refractory, and a conventionally known refractory aggregate used for forming an amorphous refractory composition can be used as it is. Examples of the refractory aggregate include alumina, bauxite, diaspore, mullite, kayanite, van earth shale, chamotte, quartzite, pyrophyllite, sillimanite, andalusite, chromite, spinel, magnesia, zirconia, zircon. One or more selected from carbon such as chromia, silicon nitride, aluminum nitride, silicon carbide, boron carbide and graphite, titanium boride and zirconium boride are preferred.

  In the present specification, as the refractory aggregate, a particulate aggregate having a particle size of 10 mm or less and more than 10 μm is preferably used. If large particles exceeding 10 mm are included, the clay may not be well-organized and a lump may not be formed, which increases rebound loss during spraying.

  Also in the above-mentioned range, it is preferable to use a combination of aggregates having two or more particle sizes and different 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 has a ratio of maximum particle diameter / inner diameter of the conveying tube as 1 / It is preferable to make it 7 to 1/3.

  More specific particle sizes are, for example, divided into different categories such as 2 mm or more and less than 6 mm, 0.1 mm or more and less than 2 mm, 30 μm or more and less than 0.1 mm, and less than 30 μm. Can do. As a preferable combination, when all aggregates are 100 mass%, aggregates of 2 mm or more and less than 6 mm are 5 to 40 mass%, aggregates of 0.1 mm or more and less than 2 mm are 10 to 35 mass%, 30 μm or more and 0 It is preferable in terms of filling property that the aggregate is less than 1 mm in the range of 10 to 30% by mass and the aggregate of less than 30 μm is in the range of 10 to 25% by mass. In addition, in this specification, a particle size says the value measured according to JISR2552.

  The blending ratio of the aggregate is preferably 65 to 90% by mass, more preferably 70 to 85% by mass in the amorphous refractory composition. When the blending ratio of the aggregate is less than 65% by mass, an increase in dust generation at the time of spraying and the fluidity of the powder are remarkably lowered, which hinders transport by the air current transport type sprayer. Conversely, if it exceeds 90% by mass, the strength and corrosion resistance of the obtained refractory cannot be obtained sufficiently.

(Fireproof powder)
The refractory powder used here forms a joint for joining the refractory aggregates by filling the gaps of the refractory aggregates, and has an average particle diameter of 10 μm or less, preferably 5 μm or less. Preferably it is used. As the refractory ultrafine powder, alumina, silica fume and the like are preferable. Such alumina and silica fume 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 blending ratio of the refractory powder is preferably 6 to 24% by mass and more preferably 10 to 20% by mass in the amorphous refractory composition. If the blending ratio of the refractory powder is less than 6% by mass, the strength and corrosion resistance of the obtained refractory cannot be sufficiently obtained, and conversely if it exceeds 24% by mass, an increase in dust generation during spraying, The fluidity of the powder becomes extremely low, which hinders the conveyance by the air current conveying type spraying machine.

  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 clay shale, chamotte, pyrophyllite, sillimanite, andalusite, quartzite, chromite, spinel, magnesia, zirconia, zircon, chromia, silicon nitride, Amorphous silica such as aluminum nitride, silicon carbide, boron carbide, titanium boride, zirconium boride or silica may be mentioned. These are used alone or in combination.

(Binder)
The binder used here should just function as a binder of an amorphous refractory, and a well-known binder is mentioned. Examples of such binders include alumina cement, high alumina cement, active magnesia, a combination of a low-reactivity alkaline earth metal oxide and a water-soluble organic acid salt or inorganic acid salt, and the like. Alumina cement is used. When alumina cement is used as a binder, the construction body can maintain strength in a wide range from room temperature to high temperature. As the binder, phosphates such as phosphoric acid and aluminum phosphate, silicates such as sodium silicate and potassium silicate, lignin sulfonate, water-soluble phenol and the like can be used.

  This binder is preferably a fine powder having an average particle size of less than 40 μm, and more preferably less than 5 μm. The average particle size of the binder is particularly preferably 1 μm or less in terms of compressive strength during curing. Moreover, in this specification, an average particle diameter means what was computed by the laser diffraction type particle size distribution measuring method.

  The blending ratio of the binder is preferably 1 to 15% by mass and more preferably 3 to 12% by mass in the amorphous refractory composition. When the blending ratio of the binder is less than 1% by mass, the strength and corrosion resistance of the obtained refractory cannot be sufficiently obtained, and the time required for curing becomes too long, which hinders on-site processes. On the other hand, if it exceeds 15% by mass, the curing time becomes too short, which hinders the finish of the construction body.

(Dispersant)
The dispersant used here suppresses the increase in viscosity when construction water is added to the powdered composition, and does not cause problems such as blocking of the transport pipe. An agent is used. Examples of the phosphoric acid dispersant used here include condensed phosphates such as sodium tripolyphosphate, sodium tetrapolyphosphate, and sodium hexametaphosphate. Among them, sodium tripolyphosphate is preferable.

  This phosphoric acid type dispersant produces a quick setting action with respect to the bonding of the amorphous refractory composition. Such a phosphoric acid-based dispersant was also blended in the conventional amorphous refractory composition, but in this embodiment, when the blending amount is increased and exceeds 0.5% by mass, it is necessary for spraying construction. Although shape retention was obtained, it was found that there was a problem that the construction body expanded and became brittle when the construction body containing moisture was cured for a long time. In order to obtain the shape retention necessary for spraying while suppressing such problems, it is effective to use a phosphoric acid-based dispersant with an external addition of 0.3% by mass or less in combination with bentonite and a lithium salt. is there.

  The blending ratio of the dispersant is preferably 0.05 to 0.3% by mass when the total of the refractory aggregate, the refractory powder, the binder and the bentonite is 100% by mass, preferably 0.1 to 0.2%. The mass% is more preferable. When the mixing ratio of the dispersant is less than 0.05% by mass, the stability and adhesion when the construction water is added to form clay is reduced, and the strength and corrosion resistance of the obtained refractory are sufficiently obtained. On the other hand, if it exceeds 0.3% by mass, there is a problem that the construction body expands and becomes brittle when the construction body containing moisture is cured for a long time.

(Bentonite)
The bentonite used here is a weakly alkaline claystone mainly composed of the clay mineral montmorillonite. In general, silicate minerals such as feldspar, mica, zeolite, etc., with silicate minerals such as quartz, α-cristobalite and opal as subcomponents. Accompanied by minerals, carbonate minerals such as calcite, dolomite, and gypsum, sulfate minerals, and sulfide minerals such as pyrite.

  This bentonite can improve the rapid setting effect when used in combination with a lithium salt. Bentonite preferably has an average particle size of 45 μm or less, and more preferably 10 μm or less.

  The blending ratio of this bentonite is preferably 0.5 to 3% by mass and more preferably 1.5 to 2.5% by mass in the amorphous refractory composition. When the blending ratio of the dispersant is less than 0.5% by mass, the stability and adhesion when the construction water is added to form clay is reduced, and the strength and corrosion resistance of the obtained refractory are sufficiently obtained. On the contrary, if it exceeds 3% by mass, the adhesiveness of the kneaded material after kneading is too strong, and there is a possibility of causing clogging in the hose.

(Lithium salt)
The lithium salt used here is an inorganic compound such as lithium carbonate or lithium chloride, and lithium carbonate is particularly preferable. In the present embodiment, a component that imparts shape retention necessary for spraying to the kneaded clay and suppresses swelling and embrittlement due to moisture of the amorphous refractory obtained by applying the amorphous refractory composition It is.

  The mixing ratio of the lithium salt is preferably 0.05 to 1% by mass, and preferably 0.1 to 0.5% by mass when the total of the refractory aggregate, the refractory powder, the binder and the bentonite is 100% by mass. Is more preferable. If the blending ratio of the lithium salt is less than 0.05% by mass, the resulting amorphous refractory material may not be able to sufficiently suppress swelling or peeling due to moisture, and conversely if it exceeds 1% by mass, spraying At this time, the kneaded clay becomes too hard and the adhesiveness falls.

In this embodiment, bentonite and lithium salt are complementary to each other, and bentonite supplements construction stability at the time of spraying, which is insufficient with only lithium salt, and lithium salt supplements shape retention that is insufficient with only bentonite.
In the amorphous refractory composition of the present embodiment, lithium salt is superior to bentonite in terms of reducing rebound loss. And from the result of this examination, it turned out that lithium salt has the effect 4.26 times or more of bentonite by content comparison by the mass reference | standard in an amorphous refractory composition. Therefore, it is preferable that the content of 4.26 times the lithium salt content and the bentonite satisfy the following range, because rebound loss in spraying can be further reduced.
4.26X + Y ≧ a
Here, X is the lithium salt content (mass%), and Y is the bentonite content (mass%).
In terms of realizing a reduction in rebound loss, a is preferably 2.6, more preferably 2.61, and even more preferably 2.63.
In the case of 4.26X + Y <2.6, the rebound loss amount is relatively large. On the other hand, when 4.26X + Y ≧ 2.6 is satisfied, the rebound loss amount is relatively small.

In the amorphous refractory composition of the present embodiment, the content ratio of the lithium salt and bentonite can affect the strength of the construction body obtained by spraying. And the intensity | strength of a construction body can be raised more by restraining these total amounts in a predetermined range. Furthermore, the influence of the above-described content ratio is that the lithium salt content ratio is higher than the bentonite content ratio. From the results of this study, the lithium salt content was compared in terms of mass basis in the amorphous refractory composition. Was found to be 8.34 times more effective than bentonite. Therefore, it is preferable that the total content of bentonite and 8.34 times the content ratio of the lithium salt satisfy the following range because the strength of the construction body can be further increased.
8.34X + Y ≦ b
Here, X is the lithium salt content (mass%), and Y is the bentonite content (mass%).
In terms of increasing the strength of the construction body, the b is preferably 7.2, more preferably 7.19, and even more preferably 7.17.
In the case of 8.34X + Y> 7.2, the amount of water becomes excessive at the time of spraying, and the denseness of the construction body may be lowered and the strength may be lowered. On the other hand, if 8.34X + Y ≦ 7.2 is satisfied, spraying is performed. Sometimes an appropriate amount of water can be maintained, the denseness of the construction body is maintained, and high strength is obtained.

  The amorphous refractory composition of the present embodiment can contain conventionally known components in addition to the above components as long as the effects of the present invention are not impaired.

  And the amorphous fireproof composition of this embodiment can be manufactured by mixing the component demonstrated above sufficiently uniformly by a well-known method.

[Unshaped refractory]
The amorphous refractory composition obtained as described above is kneaded with water to form clay and cast and sprayed into the desired location at the site where the irregular refractory is formed. Can be manufactured in shape.

  Hereinafter, a method for forming an amorphous refractory using the amorphous refractory composition of the present embodiment will be described in detail with reference to the drawings, taking spraying as an example. FIG. 1 is a diagram for explaining an airflow conveying type spraying method for an irregular refractory.

  First, the airflow conveying type spray construction apparatus for the irregular refractory used here will be described. As shown in FIG. 1, the spray construction device 1 includes an airflow transporter 2, a transport pipe 3, a construction water addition unit 4, a construction water addition unit 5, a spray nozzle 6, and a compressor 7. Is composed of.

  The air current conveying device 2 uses the compressed air of the compressor 7 to convey the amorphous refractory composition 21 into the conveying pipe 3 at a predetermined solid / gas ratio so that the amorphous refractory composition 21 can be conveyed in a powder state. The indeterminate refractory composition 21 that has been fed in is transported from one end side (airflow transporter 2 side) of the transport pipe 3 to the other end side (the spray nozzle 6 side).

  The conveyance pipe 3 is a passage that conveys the powdered amorphous refractory composition 21 in a powder state by an air current, and sprays the wet amorphous refractory composition even when construction water is added on the way. Can be transported up to. That is, the transport pipe 3 may be anything as long as it can stably transport the powdered and / or wet amorphous fireproof composition 21 by connecting the airflow transporter 2 and the spray nozzle 6.

  As this conveyance pipe 3, the pipes made from metal, such as steel, and the resin hose made from rubber, polyethylene, etc. which are used conventionally are preferred. At this time, the inner diameter of the conveying pipe 3 may be appropriately selected depending on the amount of the amorphous refractory composition 21 to be conveyed, the construction site, and the like, and is usually preferably 65 mm or less. If the inner diameter of the transport pipe exceeds 65 mm, the amount of spraying per unit time will be excessive, and if the inner diameter is too small, pressure loss will occur. In particular, the inner diameter of the transport pipe 3 is more preferably 25 to 65 mm.

  At this time, the diameter of the conveying pipe 3 can be appropriately selected depending on the amount and size of the amorphous refractory composition 21 to be conveyed, and the ratio of the maximum particle diameter in the amorphous refractory composition 21 to be used / the inner diameter of the conveying pipe is It is preferable to set it to 1/7 to 1/3, and a conveyance tube having an inner diameter of 38 to 65 mm may be usually used.

  The length of the transport pipe 3 is not limited as long as air transport can be stably performed. For example, the transport pipe 3 can transport a long distance of about 200 m in horizontal distance and about 150 m in height. Further, it is preferable that the shape of the transport pipe 3 is made of a flexible material such as resin as described above, because it can be easily arranged and moved in accordance with the situation at the site. Furthermore, even when the construction site is at a high place, the conveying pipe 3 can blow the amorphous refractory composition 21 to the high place, and the spray nozzle 6 can be brought close to the construction object, enabling stable construction. And

  The construction water addition means 4 adds construction water into the transport pipe 3 in which the powdery amorphous refractory composition 21 is transported to make the amorphous refractory composition 21 wet. The amorphous refractory composition 21 in a wet state is transported to the spray nozzle 6 by the force of the airflow from the airflow transporter 2. The construction water into the conveyance pipe 3 by the construction water addition means 4 is supplied by supplying the construction water sent by the construction water addition means 4 into the conveyance pipe by the construction water addition section 5.

  Here, the construction water addition means 4 is preferably, for example, a metal pipe made of stainless steel or the like, or a resin hose made of rubber or polyethylene. At this time, the inner diameter of the construction water addition means 4 may be appropriately selected depending on the amount of construction water to be supplied, the situation at the construction site, and the like, and usually 9 to 25 mm is preferable.

  And the construction water addition means 4 is connected to the water addition port provided in the middle of the conveyance pipe 3 so that construction water can be supplied into the conveyance pipe 3, and the construction water addition part 5 is provided. The position of the construction water addition part 5 is preferably 0.3 to 1 m from the tip of the spray nozzle 6. If the length is shorter than 0.3 m, the amorphous refractory composition 22 and the construction water may not be sufficiently mixed, and a refractory having sufficient characteristics cannot be constructed. If the length is longer than 1 m, the amorphous refractory composition is formed in the transport pipe 3. There is a possibility that the objects 21 are likely to accumulate, the spraying amount is reduced, or the inside of the transport pipe 3 is blocked and the spraying itself cannot be performed.

  The spray nozzle 6 is attached to the tip of the transport pipe 3 and sprays the amorphous refractory composition 22 to which construction water is added onto the construction object. As the spray nozzle 6, a conventional spray nozzle of an irregular refractory composition may be used.

  The compressor 7 supplies compressed gas to the airflow transporter 2. The compressed gas supplied here introduces the supplied amorphous refractory composition 21 into the conveying pipe 3 in the air current conveying machine 2, and the amorphous refractory composition 21 remains in the powder state in the conveying pipe 3. Be transported.

  The amorphous refractory composition 21 is conveyed in the conveying pipe 3 in a powder state by the compressed gas sent from the compressor 7 in the air current conveying machine 2. The airflow transport device 2 is not particularly limited as long as the powder of the amorphous refractory composition 21 can be transported by airflow. For example, a spraying device such as a needle gun (trade name) manufactured by Japan Private Co., Ltd. is used. it can.

  In addition, when feeding said powdery amorphous refractory composition 21 to the conveyance pipe 3, a predetermined amount of the irregular refractory composition 21 is continuously supplied to the airflow conveying device 2, and the compressor 7 is used as an airflow source. For example, by supplying compressed air, the conveyance amount of the amorphous refractory composition 21 per hour can be stably determined.

  Then, the amorphous refractory composition 21 fed into the transport pipe 3 is transported in the direction of the spray nozzle 6 through the transport pipe 3 by the airflow generated by the compressed air supplied to the airflow transporter 2. At this time, the length of the transport pipe 3 is related to the capability of the airflow transport machine 2, but in this embodiment, since it can be transported in powder form, it can be transported over a very long distance, for example, as long as 200 m. It is.

  Thus, the construction water is added by the construction water addition means 4 in the middle of the transport pipe 3 to the amorphous refractory composition 21 transported in the transport pipe 3. The position of the construction water addition unit 5 to which construction water is actually supplied is preferably 0.3 to 1 m upstream from the tip of the spray nozzle 6, and when the addition of water is performed at a position less than 0.3 m, The amorphous refractory composition 21 and the construction water are not sufficiently mixed, and a refractory having sufficient characteristics may not be constructed. On the other hand, when water is added at a position far beyond 1 m, the pressure resistance increases due to the addition of water, and the conveyance pipe tends to be blocked due to insufficient conveyance force with compressed air, which is not preferable. The addition position of water is more preferably 0.3 to 1 m upstream from the tip of the spray nozzle 6.

  In this embodiment, the amount of construction water added to the amorphous refractory composition 21 is substantially the entire amount of construction water required for spraying refractories. Here, “substantially” means almost all the required amount, and a small amount of water can optionally be added at other locations. For example, a small amount of water may be added to the amorphous refractory composition 21 in order to prevent the powder from rising, and a so-called premoist state may be obtained.

  For example, in a study on the structure of a powder, water and air dispersion system, in general, the three systems can take various structures, but the wet state of the refractory composition in the transport tube of the present invention The so-called “Filament (II) region” (Umeya: Gakken 136 Committee, Academic Refractory Construction Technology Council Study Group data), in which air is confined in continuous particles of water and water, Therefore, it is considered that the wet-shaped amorphous refractory composition 21 of the present embodiment is transported while floating in the transport pipe. However, this is a mechanism estimation and does not constrain the interpretation of the present invention.

  In addition, the construction water added here is supplied by the construction water addition means 4 up to the construction water addition unit 5, and the supply source of the construction water is usually arranged in the vicinity of the airflow transporter 2. Therefore, the construction water addition means 4 has the same length as the transport pipe 3.

  In this way, the construction water corresponding to a predetermined mixing ratio is added to the powdered amorphous refractory composition 21 to make it wet, and it is transported to the spray nozzle 6 and directly applied to the construction wall 22 which is the construction object. Be sprayed. Note that the transfer air is degassed into the outside air by an impact when blown against the construction wall surface 22. The sprayed amorphous refractory is rapidly agglomerated after deaeration and then hardened to become the construction refractory 23, and a strong furnace wall is constructed. In addition, you may use a formwork etc. as needed in the case of construction.

  Hereinafter, the present invention will be described in detail with reference to examples. However, the present invention is not construed as being limited by these examples.

(Examples 1-8)
The raw material powder was mixed so that it might become the mixing | blending shown in Table 1, and the amorphous refractory composition was obtained. In addition, the powder raw material used here is as follows.

<Fireproof aggregate>
Alumina-silica powder having a content of Al ₂ O ₃ of about 60% by mass is sieved to coarse particles (particle size: 6 to 2 mm), medium particles (particle size: 2 to 0.1 mm), fine particles It was set as the refractory aggregate of each particle size (particle size: 0.1 mm-).
<Fireproof powder>
Calcination alumina (Al ₂ O ₃ 98 mass% or more, average particle size 10 μm or less)

Silica fume (SiO ₂ 94 mass% or more, average particle diameter 5 μm or less)
<Binder>
Alumina cement (High alumina cement of about 70% by weight of Al ₂ O ₃ )
<Dispersant>
Sodium tripolyphosphate

<Quick setting agent>
Sodium aluminate-containing quick setting agent (AlNa ₂ O content 5-15% by mass)
<clay>
Bentonite (average particle size 45μm or less)
Kaolinite (average particle size 45μm or less)
<Metal salt>
Lithium carbonate (Li ₂ CO ₃ content 98 mass% or more)
Sodium chloride (NaCl content 98 mass% or more)
<Additive>
Explosive inhibitor (made of polypropylene; average fiber length of 5 mm or less)

(Examples 9 to 14)
The raw material powder was mixed so that it might become the mixing | blending shown in Table 2, and the amorphous refractory composition was obtained.

[Characteristic]
For each of the irregular refractory compositions obtained in Examples 1 to 14 above, the properties of adhesion, long-term curing of the construction body, storage properties of the powder composition, compressive strength, and heat spalling properties are examined. The results are shown in Tables 1-2. Each characteristic was evaluated as follows.

<Adhesiveness>
The spraying construction was carried out by the air current conveying type spraying construction method shown in FIG. In this test, the need gun 400 (made by AGC Pribrico Co., Ltd., trade name) is used as the sprayer, and the rubber diameter is 1.5B, the horizontal length is 40 m, and the nozzle is 0.5 m before the nozzle. A nozzle mix system that adds water, the discharge amount of the irregular refractory composition is about 2 t / h, and the supply amount of construction water is adjusted so that the construction body does not fall off during spraying and the amount of rebound loss is minimized. did.
A non-uniform refractory composition 250 kg was sprayed onto the construction wall surface 22 by the above method, and the material that fell without adhering was collected after the test and the mass was measured. The value calculated by the following equation was taken as the rebound loss.

Mass of recovered material / 250 × 100 = Rebound loss (mass%)

The rebound loss was evaluated as follows.
○: Less than 10%, Δ: 10% or more and less than 20%, ×: 20% or more

<Long term curing of construction body>
A 200 mm □ × 100 mm construction body sampled when the construction wall surface 22 was constructed was immersed in water and left for a maximum of 4 weeks to conduct a curing acceleration test. The state change (existence of expansion and embrittlement) on the surface of the construction body at this time was observed by visual observation and tactile sensation, and evaluated according to the following criteria.
○: No, △: Almost no, ×: Yes

<Storability of powder composition>
Whether or not the shape-retaining property necessary for spraying is maintained vertically when kneaded with a mixer after standing the amorphous refractory composition for 4 weeks in an atmosphere of 35 ° C. and 80% humidity. The steel plate was raised to a thickness of about 50 mm and a height of about 300 mm. When the iron plate was struck, it was visually confirmed that the kneaded clay did not move and was evaluated according to the following criteria.
○: Maintained, ×: Not maintained

<Compressive strength>
A test body of dimensions: 160 mm × 40 mm × 40 mm was cut out from the construction body, fired at 1000 ° C. × 3 h, and measured according to JIS R2553. The measurement results were evaluated according to the following criteria.
○: 50 MPa or more, Δ: 49 MPa or less

<Heat resistant spalling property>
In order to accelerate the results, the exfoliation rate was examined according to the JIS R 2567 refractory brick spalling test method except that a pre-fired specimen (1000 × 5h) was used, and the exfoliation rate was 5% by mass. The test was completed when the number of times exceeded (number of times), and up to 30 times. The number of times obtained at this time was evaluated according to the following criteria.
○: 20 times to 30 times, Δ: 10 times to less than 20 times, X: less than 10 times

  From the above, the amorphous refractory composition of the present embodiment can secure the same adhesion, curability, etc. as the conventional amorphous refractory composition using the quick setting agent, and is safe and has good long-term storage stability. In addition, it was found that the construction can be easily performed.

Claims (6)

An amorphous refractory composition comprising refractory aggregate, refractory powder, binder, and dispersant as essential components,
The amorphous refractory composition, wherein the dispersant contains a phosphate dispersant and further contains bentonite and a lithium salt. In the amorphous refractory composition, the bentonite contains 0.5 to 3% by mass, and
When the total amount of the refractory aggregate, the refractory powder, the binder and the bentonite is 100% by mass, the phosphoric acid dispersant is 0.05 to 0.3% by mass, and the lithium salt is 0. The amorphous refractory composition according to claim 1, which is contained in an amount of 0.05 to 1% by mass. The amorphous refractory composition according to claim 1 or 2, which satisfies the following formula (1).
4.26X + Y ≧ a (1)
(Where Y is the bentonite content (mass%), X is the lithium salt content (mass%), and a is 2.6) The amorphous refractory composition according to any one of claims 1 to 3, which satisfies the following formula (2).
8.34X + Y ≦ b (2)
(Where Y is the amount of bentonite (% by mass), X is the amount of lithium salt (% by mass), and b is 7.2)   The amorphous refractory composition according to any one of claims 1 to 4, wherein the phosphoric acid dispersant is sodium tripolyphosphate.   The amorphous refractory composition according to any one of claims 1 to 5, wherein the lithium salt is lithium carbonate.

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