JP2014015374A - Powder accelerating agent and spray application method of castable refractory - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve transportability of an accelerating agent added to a refractory composition by air flow transportation in a spray application of a castable refractory, and improve miscibility of the accelerating agent with the refractory composition.SOLUTION: A powder accelerating agent that is used at spray application of a refractory material, is added to a refractory composition by air flow transportation at a nozzle 13 or before the nozzle when the refractory composition is subjected to air flow transportation toward the nozzle 13 through a pipe arrangement 17, and includes: a first powder material that cures the refractory composition; and a second powder material that is a refractory raw material, and the powder accelerating agent is characterized in that the second powder material includes: at least 5% by mass of a particle in which a particle diameter exceeds 0.5 mm; and at least 30% by mass of a particle in which a particle diameter is at least 0.1 mm.

Description

  [Technical Field] The present invention relates to a powder rapid setting agent to be added to a refractory composition that is conveyed by airflow in a pipe and a method for spraying an irregular refractory in spraying an amorphous refractory.

  In molten metal containers such as ladle and converter, refractories are applied to the inner surface of the iron skin. This refractory is in an environment that is easily destroyed by slag contained in the molten metal or exposed to thermal shock due to the entry and exit of the molten metal. For this reason, when a refractory material is destroyed, repair of the part which was worn out by spraying the irregular refractory material is performed.

  As a method for repairing worn parts, after adding the required amount of construction water to the refractory composition constituting the irregular refractory and kneading it, it is conveyed to the nozzle by airflow, and the quick setting agent is added to the nozzle or in front of the nozzle and sprayed. Construction techniques are known (see, for example, Patent Documents 1 and 2). Examples of the quick setting agent used at this time include slaked lime, sodium aluminate, potassium aluminate, sodium silicate, potassium silicate, and sodium phosphate.

JP 2009-047317 A JP 2011-214762 A JP 2000-226268 A

  In the above-mentioned Patent Documents 1 and 2, the quick setting agent is air-flowed through the pipe by an air compressor and mixed with the refractory composition by a nozzle. At this time, since most of quick setting agents such as slaked lime are fine powders of about 100 μm or less, when mixed with the refractory composition, it is difficult to penetrate the refractory composition, and the quick setting agent and the refractory composition are sufficient. There was a problem of not mixing.

  Moreover, since the quick setting agent is a fine particle, it has a characteristic that it easily adheres in the pipe. When fine particles adhere to the inside of the pipe, there is also a problem that the adhering amount deviates from the designed blending components.

  For the problem that the quick-setting agent and the refractory composition are not sufficiently mixed, for example, as in Patent Document 3, a mixture of a powder quick-setting agent and refractory fine powder is added to the refractory composition in the nozzle. By doing so, a method has been considered in which a powder rapid setting agent is uniformly mixed with the refractory composition to stabilize spraying.

  However, even in the method of Patent Document 3, the mixing property between the refractory composition and the powder quick-setting agent is still insufficient, and the adhesion rate may not be improved. Further, the method of Patent Document 3 has a problem that the suppression of particulate adhesion in the pipe is insufficient, and the quick setting agent adheres to the pipe and becomes blocked.

  The problem to be solved by the present invention is that, when spraying an amorphous refractory, when the quick setting agent is added to the refractory composition by air flow, the mixing property of the quick setting agent and the refractory composition is improved. It is to improve and prevent the powder rapid setting agent from adhering to the pipe.

  As a result of intensive studies by the present inventors in view of the above problems, in Patent Document 3, the particle size of the refractory fine powder to be mixed with the powder quick-setting agent is such that the mixability between the fire-resistant composition and the quick setting agent, In addition, surprisingly, it has a large influence on the adhesion property, and surprisingly, particles having a particle size of more than 0.5 mm are 5% by mass or more, and particles having a particle size of 0.1 mm or more and 5 mm or less are 30% by mass or more. It has been found that the inclusion of the quick setting agent and the refractory composition can be improved, and that the powder quick setting agent can be prevented from adhering to the pipe.

The gist of the present invention is as follows.
(1) The powder rapid setting agent of the present invention is used when spraying a refractory, and when the refractory composition is air-flowed toward the nozzle through a pipe, the refractory composition is placed in front of the nozzle or the nozzle. A powder rapid setting agent added to a product by air flow conveyance, comprising: a first powder material that cures the refractory composition; and a second powder material that is a refractory raw material, The powder material of No. 2 is characterized by containing 5% by mass or more of particles having a particle size of more than 0.5 mm and 30% by mass or more of particles having a particle size of 0.1 to 5 mm. .
(2) Moreover, in the powder quick setting agent of the present invention, in the above (1), the second powder material contains 10% by mass or more of particles having a particle size of 5 mm or less and more than 0.5 mm. It is preferable to do.
(3) Further, in the powder quick setting agent of the present invention, in the above (1) or (2), the first powder material and the second powder material may have a mass ratio of 1: 3 to 3: When the ratio of 1 (in other words, the total amount of the first powder material and the second powder material is 100% by mass), the first powder material is 25 to 75% by mass and the second powder is It is preferable to contain the material at 75 to 25% by mass.
(4) Moreover, in the powder rapid setting agent of the present invention, in any one of the above (1) to (3), the first powder material is slaked lime, aluminate, silicate, magnesium hydroxide, One or more selected from the group consisting of Portland cement, sulfated clay, calcium carbonate, calcium chloride, calcium oxide, calcium hydroxide and sodium phosphate are preferred.
(5) Moreover, in the powder rapid setting agent of the present invention, in any one of the above (1) to (4), the second powder material may be alumina, siliceous, alumina-silica, alumina- Spinel, alumina-magnesia, alumina-carbon, alumina-silicon carbide, alumina-silicon carbide-carbon, magnesia, magnesia-carbon, carbon, silicon carbide, silicon nitride, zirconia, calcia It is preferable that it is 1 type, or 2 or more types of refractory materials chosen from the group which consists of quality, dolomite, chromia, chromia-magnesia, magnesia-lime, and magnesia-alumina.
(6) Moreover, this invention is a spray construction method of the irregular-shaped refractory using the powder quick-setting agent in any one of said (1)-(5), Comprising: Air current conveyance is carried out through piping. The powder rapid setting agent is added to the refractory composition discharged from the nozzle by airflow conveyance in the nozzle or in the pipe before the nozzle.

  According to the powder accelerating agent of the present invention, the second powder material comprises 5% by mass or more of particles having a particle size of more than 0.5 mm, and 30% by mass or more of particles having a particle size of 0.1 mm or more. Since it contains, it has the characteristic that the particle | grains of a powder quick-setting agent are easy to stab with respect to a refractory composition, As a result, the mixability of a powder quick-setting agent and a refractory composition can be improved.

  Further, even when the first powder material adheres to the inside of the pipe, particles having a particle diameter of 0.1 mm or more larger than the first powder material among the second powder materials are The effect of scraping off the first powder material adhering to the pipe is exhibited. In particular, the effect is large for particles having a particle size of more than 0.5 mm. Thereby, it can prevent that the 1st powder material adheres in piping.

It is the schematic which shows an example of the spray construction apparatus of the irregular refractory to which the powder quick-setting agent of this invention is applied. It is a graph which shows the relationship between the adhesion rate of the spraying material to a construction surface, and the apparent porosity of a spraying construction body.

  First, the spraying construction of the amorphous refractory to which the powder rapid setting agent of the present invention is applied will be described.

  FIG. 1 is a schematic diagram showing an example of an irregular refractory spray construction apparatus. A spray construction apparatus 1 shown in FIG. 1 is an apparatus for spraying and constructing an irregular refractory material on an inner wall surface of a ladle, a converter, etc., as an air flow type material conveying means 11, a material kneading means 12, and a material spraying means. Nozzle 13 and quick setting agent supply means 14 are connected to each other via pipes 15, 16, 17, and 18.

  The airflow type material conveying means 11 conveys the refractory composition constituting the amorphous refractory by airflow using an air compressor or the like. Although not shown in the figure, this air flow type material conveying means 11 is provided with a tank for supplying a refractory composition, and when the refractory composition is supplied from the tank, the refractory composition is discharged from the pipe 15 using an air flow by an air compressor. And conveyed to the material kneading means 12. Here, in the range where the inner diameter of the pipe 15 is 30 mm or more and 50 mm or less, the flow velocity in the pipe 15 is preferably 10 (m / s) or more and 30 (m / s) or less.

  A pipe 16 is connected to the upstream side of the pipe 15 where the material kneading means 12 is connected, and an air compressor is connected to the upstream side of the pipe 16, although not shown. Mist-like water is sent into the inside of the pipe 16 using the airflow of the air compressor, and the mist-like water is added from the pipe 16 to the refractory composition in the pipe 15. That is, the air compressor and the pipe 16 function as water adding means.

  The material kneading means 12 stirs and kneads the material obtained by adding water to the refractory composition conveyed by the airflow type material conveying means 11 through the pipe 16, and the nozzle 13 mixes the material kneaded by the material kneading means 12. Spray on the construction surface. The kneaded material is conveyed from the outlet of the material kneading means 12 through, for example, a pipe 17 having a length of 5 m to 20 m and discharged from the nozzle 13.

  The quick setting agent supply means 14 conveys the powder quick setting agent by an air flow using an air compressor or the like. The powder quick-setting agent is conveyed by airflow through the pipe 18 and added to the refractory composition (kneading material) in the nozzle 13 at the nozzle 13. The addition amount of the powder rapid setting agent is about 0.5 to 10% by mass as an outer shell with respect to 100% by mass of the refractory composition. Here, in the range where the inner diameter of the pipe 18 is 10 mm or more and 20 mm or less, the flow velocity in the pipe 18 is preferably 10 (m / s) or more and 40 (m / s) or less.

  As the refractory composition used in such a spray construction apparatus 1, the material is not particularly limited, and the main refractory raw materials are alumina, siliceous, alumina-silica, alumina-spinel, Alumina-magnesia, alumina-carbon, alumina-silicon carbide, alumina-silicon carbide-carbon, magnesia, magnesia-carbon, carbon, silicon carbide, silicon nitride, zirconia, calcia, dolomite The material which is quality, chromia, chromia-magnesia, magnesia-lime, magnesia-alumina, and combinations thereof can be used without problems. Usually, a material having a mineral composition similar to the refractory to be sprayed may be selected.

  Next, the powder rapid setting agent of this invention added to said fireproof composition is demonstrated.

  The powder rapid setting agent of this invention contains the 1st powder material which hardens a refractory composition, and the 2nd powder material which is a refractory raw material which has fire resistance.

  Moreover, the powder quick-setting agent of the present invention needs to be a dry powder. This is because the strength of the construction body is reduced when moisture is added to the powder rapid setting agent.

  As the first powder material, slaked lime, aluminate (sodium aluminate, potassium aluminate, calcium aluminate), silicate (sodium silicate, potassium silicate), magnesium hydroxide, Portland cement, sulfated clay, carbonic acid It is preferable to use a known quick-setting agent such as calcium, calcium chloride, calcium oxide, calcium hydroxide, sodium phosphate, or a combination thereof. Most of the first powder material is preferably one having a particle size of 0.075 mm or less.

  The material for the second powder material is not particularly limited as long as it is a refractory raw material, and the same material as the above refractory composition can be used without any problem. For example, as the second powder material, alumina, siliceous, alumina-silica, alumina-spinel, alumina-magnesia, alumina-carbon, alumina-silicon carbide, alumina-silicon carbide-carbon , Magnesia, magnesia-carbon, carbon, silicon carbide, silicon nitride, zirconia, calcia, dolomite, chromia, chromium-magnesia, magnesia-lime, magnesia-alumina It is preferable to use a refractory material that is a material and a combination thereof.

  Hereinafter, the first powder material will be described as slaked lime, and the second powder material will be described as alumina.

  In the present invention, the alumina contains 5% by mass or more of particles having a particle size of more than 0.5 mm and 30% by mass or more of particles having a particle size of 0.1 to 5 mm.

  Thereby, the powder quick-setting agent according to the present invention is compared with a powder quick-setting agent that does not contain alumina, and a powder quick-setting agent that contains alumina but does not satisfy the above conditions. It has the characteristic of being easily pierced. This characteristic is due to the presence of a predetermined amount or more of 0.1 mm or more particles contained in alumina. One specific reason is that particles of 0.1 mm or more contained in alumina have a larger particle size than most slaked lime. Furthermore, alumina has a higher specific gravity than slaked lime. For this reason, the 0.1 mm or more particle | grains more than the predetermined amount contained in an alumina have higher kinetic energy than slaked lime. If it does so, it is because the particle | grains of 0.1 mm or more contained in an alumina have the characteristic which is easy to pierce into a refractory composition rather than slaked lime. In addition, the presence of particles of 0.5 mm or more in a predetermined amount or more increases the kinetic energy of the quick setting agent as a whole, and has the property of being easily stuck into the refractory composition. Further, since slaked lime is mostly fine particles of particles smaller than 0.075 mm, it has the property of easily entering the uneven portions of alumina. For this reason, slaked lime has the property of being pierced into the refractory composition together with particles of 0.1 mm or more of alumina.

  That is, the powder quick-setting agent according to the present invention has a characteristic that it is easy to penetrate into the refractory composition as compared with the powder quick-setting agent not containing alumina. Thereby, the effect which improves the mixability of a powder quick-setting agent and a refractory composition is exhibited.

  Moreover, since the particle | grains of 0.1 mm or more contained in an alumina have a larger particle size than the slaked lime of a fine powder area, the effect which scrapes off the slaked lime adhering to piping is exhibited. For this reason, alumina needs to contain particles of 0.1 mm or more. Furthermore, particles larger than 0.5 mm have a high kinetic energy when the quick setting agent is conveyed by airflow conveyance in the pipe, and the particles larger than 0.5 mm are very effective due to the presence of a predetermined amount or more. It is possible to prevent the pipe from adhering.

  In alumina, when the particle size is 0.1 mm or more and 5 mm or less is less than 30% by mass, or the particle size exceeding 0.5 mm is less than 5% by mass, the above-described effects cannot be sufficiently obtained. In order to make the above-described effect of piercing and the effect of scraping off more remarkable, it is preferable that alumina contains coarse particles. Specifically, the particle size is 100% by mass with respect to the total amount of alumina of 100% by mass. It is preferable to contain at least 10% by mass of particles exceeding 0.5 mm.

  The upper limit of the particle size of the coarse particles in alumina is preferably 5 mm. The upper limit of the particle size of coarse particles in alumina is limited by the diameter of the pipe 18. Here, the diameter of the pipe 18 is preferably about 10 mm or more and 20 mm or less. When the diameter of the pipe 18 is less than 10 mm, since the diameter is small, the powder rapid setting agent is likely to be blocked. Moreover, when the diameter of the pipe 18 exceeds 20 mm, it is necessary to increase the air flow rate (air flow rate) for air-conveying the powder quick-setting agent as the diameter increases. When the air flow rate increases, there is a problem that air blows away the construction body on the surface of the work body, and the adherence of the construction body decreases. For this reason, the diameter of the pipe 18 is preferably 10 mm or more and 20 mm or less. Here, when the diameter of the pipe 18 is 10 mm and the particle diameter of alumina exceeds 5 mm, the tendency of the alumina to be blocked by the pipe 18 increases. For this reason, the particle size of alumina is preferably 5 mm or less.

  In addition, even when the particle diameter of alumina contains more than 5 mm, if the content of more than 5 mm in the powder rapid setting agent is less than 30% by mass, the possibility that the alumina is clogged is low, This is a practical level.

  In addition, there is no upper limit to the content of coarse particles having a particle size of 0.1 mm or more or a particle size exceeding 0.5 mm in the above-mentioned alumina, and all of the alumina particles have a particle size of 0.1 mm or more or a particle size of 0.5 mm or more. It may be. Even if alumina does not contain fine particles, the refractory composition usually contains fine particles, and the amount of alumina added is very small compared to the refractory composition, which adversely affects the quality of the sprayed body. Will not affect.

  In the powder quick setting agent of the present invention, the blending ratio of the slaked lime and alumina is from 1: 3 to 3: 1 in mass ratio, in other words, when the total amount of slaked lime and alumina is 100% by mass, It is preferable to mix slaked lime in a proportion of 25 to 75 mass% and alumina in an amount of 75 to 25 mass%. When the content of slaked lime is less than 25% by mass, the component for curing the refractory composition is insufficient, and the adhesion rate to the construction surface tends to decrease. On the other hand, when the content ratio of alumina is less than 25% by mass, air transportability is lowered, and the powder quick-setting agent may adhere to the pipe in the pipe, which may block the pipe.

  Furthermore, a powder quick-setting agent made of only the first powder material such as slaked lime, which is generally used in the past, is held in a storage tank for storage, or the quick-setting agent in FIG. 1 is supplied during construction. When held in the means 14, the powder rapid setting agent solidifies due to reaction with water vapor in the air, making it impossible to carry the air current, so it could only be held for about several hours to one day, If the powder quick-setting agent of the present invention is used, the presence of the second powder material such as alumina inhibits the consolidation of the first powder material such as slaked lime and holds it continuously for one week or more. However, the powder quick-setting agent does not solidify and can maintain a state in which the air current can be conveyed over a long period of time.

A construction test was conducted with the spray construction apparatus of FIG. In the test, an alumina raw material whose particle size was adjusted as a refractory composition was used, and various powder quick setting agents shown in Table 1 were added. The addition amount of the powder setting agent was 3% by mass as an outer shell with respect to 100% by mass of the refractory composition.

  Further, as the powder rapid setting agent, slaked lime and sodium aluminate having a particle size of 0.075 mm or less as the first powder material, and the electric powder having the predetermined particle size distribution shown in Table 1 as the second powder material. Fused alumina was used.

  As the evaluation of the test, the blockage in the pipe and the adhesion rate were evaluated. When the mixing property of the powder quick-setting agent and the refractory composition is improved, the adhesion rate is improved. For this reason, the adhesion rate was also evaluated as an evaluation item. Specifically, the evaluation of the blockage in the pipe was performed by the blockage rate by the powder quick-set agent on the cross section of the pipe 18 in FIG. ○ indicates a blocking rate of 0%, Δ indicates a blocking rate of 10% or less, and x indicates a blocking rate of 100%. The adhesion rate was evaluated by “adhesion rate (%) = weight of construction body adhered to construction surface / (weight of sprayed raw material (unshaped refractory) discharged from nozzle)) × 100”.

Here, a panel having a shape of 500 mm × 500 mm, a construction temperature of 900 ° C., a construction flow rate (output flow rate of an air compressor (not shown) connected to the air flow type material conveyance means 11 through a conveyance path) 4 to 5 (m ³ / min), the test was conducted under the conditions of a refractory composition conveyance speed of 20 (m / s) and a powder rapid setting agent conveyance speed of 25 (m / s).

  In FIG. 2, using the spray construction apparatus of FIG. 1, the mass ratio of the powder quick setting agent slaked lime and fused alumina is 1: 1, and the particle size distribution of fused alumina is changed. The relationship between the adhesion rate of the obtained construction body and the apparent porosity is shown. FIG. 2 shows that when the adhesion rate is 80% or more, the apparent porosity is stable at a low level, and a good construction body can be obtained. Therefore, in the comprehensive evaluation, (1) occlusion in the pipe is ○ and the adhesion rate is 80% or more, ◎, (2) occlusion in the pipe is o or Δ, and the adhesion rate is 78% or more, (3 ) The blockage in piping was Δ or x, and the adhesion rate was 75% or less as x.

  As shown in Table 1, Examples 1-6, Examples 8-10, and Examples 14 and 15 were all evaluated as 総 合, and good results were obtained.

  In Example 7, the overall evaluation is ○, which is slightly inferior to the other examples. In Example 7, since the proportion of slaked lime in the total amount of slaked lime and fused alumina is as small as 20% by mass, it is estimated that the component for curing the refractory composition is insufficient and the adhesion rate is slightly reduced. However, since Example 7 is ◯ in the comprehensive evaluation and is superior to the comparative example described later, it is at a level that is sufficiently practical in other than a severe environment.

  In addition, Examples 11, 12 and 13 have a comprehensive evaluation of ◯, which is slightly inferior to the other examples. Since Examples 11, 12, and 13 contain more than 5 mm of fused alumina, it is presumed that the tendency to block the pipe 18 has increased. However, since Examples 11, 12, and 13 have a comprehensive evaluation of “◯” and are superior to Comparative Examples described later, they are at a sufficiently practical level.

  In Comparative Examples 1 to 3, the ratio of the particles having a particle size of 0.1 mm or more and 5 mm or less in the fused alumina is less than 30% by mass, the evaluation of the plugging ability is lowered, and the adhesion rate is also lowered. Yes. In Comparative Example 3, the ratio of fused alumina to the total amount of slaked lime and fused alumina is as low as 20% by mass.

  In Comparative Example 4, the proportion of particles having a particle size of more than 0.5 mm in the fused alumina is less than 5% by mass. For this reason, the evaluation of the piping blocking property is lowered, and the adhesion rate is also lowered.

  The comparative example 5 is an example which contains only slaked lime in a powder quick-setting agent. In this case, the powder quick-setting agent is difficult to penetrate into the refractory composition, and the powder quick-setting agent and the refractory composition are not sufficiently mixed.

  From the above, it is important that the second powder material contains 5% by mass or more of particles having a particle size of more than 0.5 mm and 30% by mass or more of particles having a particle size of 0.1 mm or more. The second powder material preferably contains 10% by mass or more of particles having a particle size of 5 mm or less and more than 0.5 mm.

  Further, in the examples, the powder accelerating agent was sometimes retained in the rapid accelerating agent supply means 14 shown in FIG. 1 for one week or more. I was able to carry it.

  The powder rapid setting agent of the present invention includes, for example, a converter, ladle, blast furnace, firewood, kneading car, electric furnace, secondary refining furnace, tundish, rotary kiln, waste melting furnace, waste ash melting furnace, incineration The present invention can be widely used for spraying an irregular refractory material for repairing a lining of a molten metal container such as a furnace, a cement plant furnace, a soaking furnace, or a heating furnace, or for forming an initial lining. Moreover, the powder rapid setting agent of this invention can be utilized for both hot construction and cold warm construction.

DESCRIPTION OF SYMBOLS 1 Spray construction apparatus 11 Airflow-type raw material conveyance means 12 Material kneading means 13 Nozzle 14 Rapid setting agent supply means 15, 16, 17, 18 Piping

Claims (6)

Powder quenching agent used in spraying refractory and added to the refractory composition by airflow before the nozzle or nozzle when the refractory composition is transported to the nozzle through a pipe Because
A first powder material for curing the refractory composition;
A second powder material that is a refractory raw material,
The second powder material contains 5% by mass or more of particles having a particle size exceeding 0.5 mm and 30% by mass or more of particles having a particle size of 0.1 mm or more. Binder.   2. The powder rapid setting agent according to claim 1, wherein the second powder material contains 10% by mass or more of particles having a particle diameter of 5 mm or less and greater than 0.5 mm.   The powder powder according to claim 1 or 2, wherein the first powder material and the second powder material are contained at a mass ratio of 1: 3 to 3: 1. Binder.   The first powder material is selected from the group consisting of slaked lime, aluminate, silicate, magnesium hydroxide, Portland cement, sulfated clay, calcium carbonate, calcium chloride, calcium oxide, calcium hydroxide and sodium phosphate. The powder rapid setting agent according to any one of claims 1 to 3, wherein the powder quick setting agent is one kind or two or more kinds.   The second powder material is alumina, siliceous, alumina-silica, alumina-spinel, alumina-magnesia, alumina-carbon, alumina-silicon carbide, alumina-silicon carbide-carbon, magnesia. Quality, magnesia-carbonaceous, carbonaceous, silicon carbide, silicon nitride, zirconia, calcia, dolomite, chromia, chromia-magnesia, magnesia-lime and magnesia-alumina It is a 1 type, or 2 or more types of refractory material, The powder quick setting agent of any one of Claims 1-4 characterized by the above-mentioned.   A method for spraying an irregular refractory using the powder quick-setting agent according to any one of claims 1 to 5, wherein the refractory composition is air-flowed through a pipe and discharged from a nozzle. A method for spraying an amorphous refractory, wherein the powder rapid setting agent is added to the nozzle or a pipe before the nozzle by airflow conveyance.

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