JP5865279B2 - Unshaped refractory for spraying - Google Patents

Description

  The present invention relates to lining refractories of various metal containers such as blast furnaces, firewood, kneading cars, converters, ladle, secondary refining furnaces, tundish, cement rotary kilns, waste melting furnaces, incinerators, and non-ferrous metal containers. The present invention relates to an indeterminate refractory for spraying that is constructed in repairs and the like.

  The construction of an irregular refractory material for spraying is basically performed by adding water to the refractory material, but depending on the method of adding water and mixing and kneading with the refractory material, the wet spraying method and the dry-type refractory material are used. It is roughly divided into the installation method. The wet spraying construction method is a construction method in which a refractory material and water are kneaded in advance by a mixer or the like, the kneaded product is pumped, and a binder (rapid setting agent) is introduced and sprayed at a spray nozzle portion. On the other hand, the dry spraying construction method is a construction method in which a refractory material containing a binder is air-conveyed in a dry powder state without being previously kneaded, and water is added and sprayed in a spray nozzle portion.

  2. Description of the Related Art Conventionally, a technique for adding a saccharide material to an indeterminate refractory for spraying used in such a wet or dry spraying method is known. For example, Patent Document 1 discloses a method for increasing the viscosity in order to suppress separation of water, a rapid setting accelerator, a dispersant, a refractory raw material fine powder and the like in a slurry-type quick setting agent used in a wet spraying method. A technique of adding a water-soluble natural polymer polysaccharide (biogum thickener) as an agent is disclosed. Patent Document 2 discloses a technique of adding a saccharide such as sucrose to improve the adhesiveness, dispersibility, and adhesive strength of a repair material for a sliding nozzle plate brick.

JP 2007-39256 A JP 59-18173 A

  The irregular refractory material for spraying is required to have excellent workability as well as excellent adhesion (bonding strength) to the work surface. In this regard, Patent Document 1 describes that a water-soluble natural polymer polysaccharide is added in order to prevent separation of the slurry. Although consideration is given to workability, adhesion to a work surface is known. No mention is made of adding a water-soluble saccharide material to improve the performance. In Patent Document 1, it is preferable to add water-soluble natural polymer polysaccharide to 0.005% by mass or more and 0.5% by mass or less with respect to 100% by mass of the refractory raw material fine powder in the slurry-like quick setting agent. (Paragraph 0044). This addition amount is extremely small when converted to the addition amount with respect to 100% by mass of the refractory raw material including aggregates other than fine powder (Table 1). For this reason, it is not a level with an effect in the adhesive improvement with respect to a to-be-processed surface.

  Patent Document 2 describes that the refractory material is composed only of fine powder of 100 mesh or less (about 0.1 mm or less) (Table 1). Thus, when what comprised the refractory material only with fine powder is applied to spray construction, fine powder will absorb water | moisture and become lumps, and the whole refractory material is not mixed uniformly. That is, since the material with insufficient mixing is conveyed through the nozzle, a so-called pulsation phenomenon occurs in which the material is discharged non-uniformly when sprayed from the spray nozzle. When pulsation is caused by spraying construction, the construction body becomes uneven, leading to a decrease in the durability of the construction body.

  In addition, when the refractory material is composed only of fine powder, since there are no coarse particles, it is difficult to secure a route through which moisture escapes from the construction body. When it becomes difficult for moisture to escape from the construction body, it accumulates in the construction body in the state of water or water vapor, and becomes a void after drainage. When voids are generated, molten metal and slag enter and melt, and the durability of the construction body decreases. In addition, if the moisture in the construction body does not escape and water or water vapor is excessively accumulated in the construction body, the vapor pressure in the construction body increases, and there is a risk of causing a so-called explosion phenomenon that the construction body collapses vigorously.

  Furthermore, the repair material of Patent Document 2 is basically used for repair of a sliding nozzle plate brick. Since only a very small amount of repair material is used for repairing sliding nozzle plate bricks, the effect of dehydration is small. However, if the construction area is larger and the construction thickness is larger than the repair of the sliding brick plate brick, such as spraying construction for repairing the refractory lining the kiln, the construction volume is large. The effect of moisture retention in the body and a decrease in service life appears remarkably.

  Therefore, the problem to be solved by the present invention is to improve the dewaterability of the irregular shaped refractory for spraying to obtain a dense construction body and to improve the adhesion to the work surface. The purpose is to increase the durability of regular refractories.

  According to one aspect of the present invention, there is provided an amorphous refractory for spraying containing a refractory material, a binder and a water-soluble saccharide material, wherein particles are contained in a total amount of 100% by mass of the refractory material and the binder. Coarse particles having a diameter of 1 mm or more are contained in an amount of 15% by mass or more and 55% by mass or less, and fine particles having a particle size of 75 μm or less are contained in an amount of 15% by mass or more and 40% by mass or less, and the water-soluble carbohydrate material is contained in the refractory material and binder. An amorphous refractory for spraying is provided in which 2% by mass or more and 15% by mass or less are added to the total amount of 100% by mass.

  According to the present invention, since a specific amount of coarse particles having a particle diameter of 1 mm or more is contained, it is possible to secure a route through which moisture escapes from the construction body. In addition, since the content of fine particles having a particle size of 75 μm or less is specified in a specific range, the refractory material and water are easily mixed, and it is not necessary to add a large amount of water. Can be obtained.

  Furthermore, since a specific amount of water-soluble saccharide material is added, the water-soluble saccharide material acts as a dispersant in the refractory material during construction, and the curing reaction of the refractory material is alleviated. It becomes easy to adhere to the unevenness of the work surface. In addition, when the saccharide material is heated, water in the structure is evaporated by a dehydration reaction, and a polymer obtained by dehydration polymerization remains in the material. Therefore, the carbon component in the polymer forms a carbon bond at the adhesion interface with the work surface, and the adhesion to the work surface can be improved.

  The amorphous refractory for spraying of the present invention comprises a refractory material, a binder and a water-soluble saccharide material.

  As the refractory material and the binder, those generally used in the conventional refractories for wet or dry spraying can be used. For example, examples of the refractory material include alumina, silica, magnesia, calcia, silicon carbide, carbon and the like, and a combination of two or more of these also corresponds to this. Examples of the binder include cement, phosphate, silicate, chloride, sulfide, hydroxide, silica sol, and alumina sol.

  Examples of the saccharide material include saccharides (monosaccharides and disaccharides), polysaccharides, oligosaccharides, sugar alcohols and the like. Among these, water-soluble materials are used in the present invention. The water-soluble saccharide material acts as a dispersant in the refractory material during construction as described above. In order to exhibit good dispersibility in the presence of water at the time of construction, it is preferable to use water-soluble monosaccharides such as fructose and glucose that have a small molecular weight and can easily incorporate water into the structure.

  The irregular shaped refractory for spraying of the present invention contains 15 to 55% by mass of coarse particles having a particle size of 1 mm or more in a total amount of 100% by mass of the refractory material and the binder, and fine particles having a particle size of 75 μm or less. 15 mass% or more and 40 mass% or less.

  When the coarse particle having a particle diameter of 1 mm or more is less than 15% by mass, the fine particles in the refractory material increase and the mixing with water becomes worse. For this reason, pulsation occurs during spraying, resulting in a non-uniform construction body, and voids may be generated. In addition, there is a risk of explosion if the moisture in the construction body does not escape and the vapor pressure in the construction body becomes excessively high. On the other hand, if the coarse particles having a particle diameter of 1 mm or more exceed 55% by mass, the coarse particles in the refractory material increase, the filling property of the refractory material is lowered, and a dense construction body cannot be obtained. Moreover, in spray construction, the rebound phenomenon increases and the workability deteriorates.

  On the other hand, when the fine particles having a particle diameter of 75 μm or less are less than 15% by mass, the fine powder in the construction body is reduced, the filling property of the refractory material is lowered, and a dense construction body cannot be obtained. Moreover, when the fine powder in a refractory material decreases, the reactivity with a binder and a carbohydrate material will worsen, and durability will fall by the fall of the strength of a construction body, the adhesive fall with respect to a to-be-constructed surface, etc. On the other hand, when the fine particle having a particle size of 75 μm or less exceeds 40% by mass, the mixing property of the refractory material and water is deteriorated, and the spray construction is accompanied by pulsation, and a uniform construction body cannot be obtained. Also, in order to compensate for poor mixing of refractory materials and water, when constructed with a large amount of moisture, it becomes a porous construction body. When the dehydration is poor, voids are generated, and further, an explosion phenomenon of the construction body occurs. There is also danger.

  In the sprayed amorphous refractory of the present invention, the water-soluble saccharide material is added in an amount of 2% by mass or more and 15% by mass or less on the basis of the total amount of the refractory material and the binder of 100% by mass. When the addition amount of the saccharide material is less than 2% by mass, the action as a dispersant in the refractory material is lowered, and the adhesion to the uneven portion of the work surface is deteriorated. On the other hand, when the addition amount of the sugar material exceeds 15% by mass, the volatile content in the material becomes excessive, the structure of the construction body becomes porous, the construction body strength is lowered, and the durability is also lowered.

  The irregular refractory for spraying of the present invention can contain a dispersant, a water reducing agent, a thickener and the like as necessary in addition to the above refractory material, binder and water-soluble saccharide material. .

  In addition, while obtaining a precise construction body and improving the adhesiveness to a to-be-processed surface, 20 mass% or more and 40 mass% of coarse grains with a particle diameter of 1 mm or more in the total amount of 100 mass% of the refractory material and the binder 20% by mass or more and 30% by mass or less of fine particles having a particle size of 75 μm or less, and 3% by mass or more of the water-soluble saccharide material as an outer shell with respect to 100% by mass of the total amount of the refractory material and the binder It is preferable to add 10% by mass or less.

  The above irregular refractories for spraying of the present invention can be applied to both wet and dry spraying constructions. As the construction method, a conventional general method can be used as it is. In addition, since a binder is added in a spray nozzle part in wet spray construction, the structure after adding the binder should just satisfy the prescription | regulation of this invention.

  The irregular refractory material for spraying shown in Table 1 was sprayed onto the work surface by adding water at the spray nozzle portion by a dry spraying method, and its workability and dehydration time were evaluated. In Table 1, “3 to 1 mm” means 3 mm or less and 1 mm or more, and “1 to 0.075 mm” means less than 1 mm and more than 0.075 mm. Moreover, silicate and slaked lime (calcium hydroxide) were used as the binder.

  In Table 1, the construction volume is shown by indexing the construction volume of Comparative Example 1 (length 200 × width 200 × thickness 50 mm) as 100. The construction volume of Comparative Example 1 corresponds to the construction volume at the time of repairing the sliding nozzle plate brick assumed in Patent Document 2.

  The workability of spray construction is evaluated based on the quality of mixed water (presence of pulsation) and the presence or absence of rebound phenomenon. If the mixed water is bad or the rebound phenomenon is observed, X is indicated. As evaluated.

  As the dehydration time, the time during which the moisture content in the construction body sprayed on the surface to be constructed at 700 ° C. was 0.5% by mass or less was measured.

  In addition, the adhesive strength was measured as a physical property value representing the adhesiveness of the sprayed amorphous refractory, and comprehensive evaluation was performed together with the evaluation results of the above workability and dehydration time.

  The adhesive strength was measured by the following method assuming hot construction. Place brick in an atmosphere of 700 ° C., and set a cylindrical metal frame on it. An indeterminate refractory for spraying (construction material) kneaded with an appropriate amount of water is cast into the metal frame, and after a certain period of time, the shear strength between the construction material and the brick is measured while the metal frame is set. In Table 1, the shear strength of Comparative Example 1 is shown as indexed to 100.

Comprehensive evaluation evaluated in four steps, (double-circle), (circle), (triangle | delta), and x. The evaluation criteria are as follows.
◎: When workability is good, dehydration time is less than 100 minutes, and bond strength index is all satisfying 110 or more ○: Workability is good, dehydration time is less than 100 minutes, and bond strength index is all satisfying 100 or more △: When workability is x, dehydration time is less than 100 minutes, and any one of bond strength index less than 100 x: Workability is x, dewatering time is 100 minutes or more, and bond strength index is less than 100 If more than one.
As a result of verification with the actual machine, if the overall evaluation is ◎ or ○, there is no problem in workability and durability, while in the case of △, construction is possible but the durability is insufficient. It was impossible.

  As shown in Table 1, in Examples 1 to 14 within the scope of the present invention, the overall evaluation was good with ◎ or ○.

  On the other hand, Comparative Example 1 corresponds to the repair material of Patent Document 2, and is an example in which all of the refractory raw material is made of fine particles having a particle size of 75 μm or less. Poor water mixing caused pulsation during construction. Comparative Example 2 is an example in which the construction volume of Comparative Example 1 is increased. The pulsation occurred during construction and the dehydration deteriorated, causing the construction to swell.

  Comparative Example 3 is an example in which there are too few coarse particles having a particle size of 1 mm or more. Poor water mixing caused pulsation during construction and dehydration.

  Comparative Example 4 is an example in which there are too many coarse particles having a particle diameter of 1 mm or more. A rebound phenomenon was observed during construction, and the rebound loss increased and the compactness of the construction body decreased.

  Comparative Example 5 is an example in which there are too few fine particles having a particle size of 75 μm or less. A rebound phenomenon was observed during construction, and the rebound loss increased and the compactness of the construction body decreased.

  Comparative Example 6 is an example in which there are too many fine particles having a particle size of 75 μm or less. Poor water mixing caused pulsation during construction and dehydration.

  Comparative Example 7 is an example in which the amount of carbohydrate material added is too small. Adhesiveness to the work surface deteriorated, and adhesion to the work surface deteriorated.

  Comparative Example 8 is an example in which the amount of carbohydrate material added is too large. The volatile matter became excessive, the structure of the construction body became porous, the strength of the construction body was reduced, and the adhesion to the work surface was deteriorated.

Claims (2)

An irregular refractory for spraying containing a refractory material, a binder and a water-soluble saccharide material,
In a total amount of 100% by mass of the refractory material and the binder, 15% to 55% by mass of coarse particles having a particle size of 1 mm or more and 15% to 40% by mass of fine particles having a particle size of 75 μm or less are contained. ,
An amorphous refractory for spraying, wherein the water-soluble saccharide material is added in an amount of 2% by mass to 15% by mass with respect to a total amount of 100% by mass of the refractory material and the binder. In a total amount of 100% by mass of the refractory material and the binder, 20% to 40% by mass of coarse particles having a particle size of 1 mm or more and 20% to 30% by mass of fine particles having a particle size of 75 μm or less are contained. ,
2. The non-specific refractory for spraying according to claim 1, wherein the water-soluble saccharide material is added in an amount of 3% by mass or more and 10% by mass or less as an outer shell with respect to 100% by mass of the total amount of the refractory material and the binder. object.