JP6880428B1 - Sprayed refractory composition and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sprayed refractory composition containing a post-use product having high adhesiveness, low rebound loss, reduced sorting time and cost, and easy procurement. SOLUTION: The sprayed fireproof composition mainly contains magnesia spinel brick dust and magnesia raw material as fireproof raw materials, and the content of magnesia spinel brick scrap is 10% by mass or more with respect to 100% by mass of the fireproof raw material. The content of the magnesia raw material is 0% by mass or more and 90% by mass or less with respect to 100% by mass of the refractory raw material. [Selection diagram] None

Description

The present disclosure relates to a spray refractory composition mainly used for steel production equipment and a method for producing the same.

Refractories used in steel production equipment wear out as they are used, so they may be sprayed and repaired to extend their life. For example, Patent Document 1 discloses a spray repair material for a steel smelting furnace using a magnesia clinker and a spinel clinker.

On the other hand, in response to growing needs for resource saving, after-use brick scraps and used amorphous refractories may be reused as refractory raw materials. For example, Patent Document 2 is a mixture of a recycled raw material of used or unused magnesia spinel-based fired brick, an alumina raw material, a magnesia raw material and / or a spinel raw material, and is an impurity Na ₂ O + K ₂ O + TiO ₂ Disclosed is a method for producing a magnesia / spinel-based fired brick for firing a raw material compound having a total content of less than 0.5% by mass on the outside. Further, Patent Document 3 discloses an amorphous refractory for wet spraying containing an amorphous refractory made of alumina-magnesia.

Japanese Unexamined Patent Publication No. 58-120568 JP-A-2018-154516 Japanese Unexamined Patent Publication No. 2005-179130

The sprayed refractory composition is generally required to improve the adhesiveness to the sprayed surface and reduce the rebound loss, but these are not sufficient for the sprayed refractory composition containing the after-use product.

In addition, since brick scraps and used amorphous refractories contain more impurities than before use, the performance of refractories blended with them as raw materials is generally considered to be inferior. Therefore, Patent Document 2 discloses used or unused magnesia spinel calcined bricks having less impurities as a recycled raw material. However, it takes time and cost to sort the used products, and it is difficult to procure the required amount.

The aspect of the present disclosure is made in view of the above-mentioned actual conditions, and the purpose of the present disclosure is to provide a used product that has high adhesiveness, low rebound loss, reduced sorting time and cost, and is easy to procure. It is to provide the compounded spray fireproof composition.

One aspect of the present disclosure includes mainly magnesia spinel brick scraps and magnesia raw materials as refractory raw materials, and the content of magnesia spinel brick scraps is 10% by mass or more with respect to 100% by mass of the refractory raw materials, and the magnesia raw materials. The present invention relates to a sprayed fireproof composition, wherein the content of the above is 0% by mass or more and 90% by mass or less with respect to 100% by mass of the fireproof raw material. A sprayed fireproof composition in which the content of the magnesia raw material is 0% by mass or more and 90% by mass or less with respect to 100% by mass of the fireproof raw material and the content of magnesia spinel brick waste is 10% by mass or more with respect to 100% by mass of the fireproof raw material. High adhesiveness and low rebound loss.

In one aspect of the present disclosure, it is preferable that the total content of the magnesia spinel brick dust and the magnesia raw material is 80% by mass or more with respect to 100% by mass of the fireproof raw material. The spray refractory composition has higher adhesiveness and less rebound loss.

In one aspect of the present disclosure, _{the total content of Na 2} O, K ₂ O, SO ₃ and Cl contained in the magnesia spinel brick waste is 0.5% by mass or more with respect to 100% by mass of the magnesia spinel brick waste 5 It is preferably 0.0% by mass or less. The sprayed refractory composition containing magnesia spinel brick dust having a total content of impurities Na ₂ O, K ₂ O, SO ₃ and Cl of 0.5% by mass or more and 5.0% by mass or less has high adhesiveness and rebounds. There is little loss. Further, the magnesia spinel brick waste after use in the cement rotary kiln has _{a total content of impurities Na 2} O, K ₂ O, SO ₃ and Cl of 0.5% by mass or more and 5.0% by mass or less, and is a component. Since it can be used without adjustment, sorting time and cost can be reduced and procurement can be facilitated.

In one aspect of the present disclosure, _{the total content of Na 2} O, K ₂ O, SO ₃ and Cl contained in the fire-resistant raw material is 0.2% by mass or more and 5.0% by mass or less with respect to 100% by mass of the fire-resistant raw material. It is preferable to have. _{If the total content of Na 2} O, K ₂ O, SO ₃ and Cl contained in the refractory raw material is 0.2% by mass or more and 5.0% by mass or less with respect to 100% by mass of the sprayed refractory composition, the adhesiveness is further improved. High and low rebound loss.

In one aspect of the present disclosure, _{the total content of Na 2} O, K ₂ O, SO ₃ and Cl contained in the spray refractory composition is 1.0% by mass or more and 5.0 by mass or more with respect to 100% by mass of the spray refractory composition. It is preferably mass% or less. Further adhesion when the total content of Na ₂ O, K ₂ O, SO ₃ and Cl contained in the spray refractory composition is 1.0% by mass or more and 5.0% by mass or less with respect to 100% by mass of the spray refractory composition. High quality and low rebound loss.

In another aspect of the present disclosure, in a method for producing a sprayed refractory composition in which magnesia spinel bricks are mainly added as a refractory raw material and a magnesia raw material is added, the content of the magnesia spinel bricks is 100% by mass of the refractory raw material. 10% by mass or more, the content of the magnesia raw material is 0% by mass or more and 90% by mass or less with respect to 100% by mass of the refractory raw material, and the magnesia spinel waste is composed of magnesia spinel brick after use in a cement rotary kiln. The present invention relates to a method for producing a sprayed refractory composition. The sprayed refractory composition to which magnesia spinel brick waste is added after use in a cement rotary kiln has high adhesiveness, low rebound loss, and further, sorting time and cost are reduced, and procurement can be facilitated.

Hereinafter, preferred embodiments of the present disclosure will be described in detail. It should be noted that the present embodiment described below does not unreasonably limit the content of the present disclosure described in the claims, and all of the configurations described in the present embodiment are essential as a means of solving the present disclosure. Is not always the case.

The sprayed fireproof composition of the present embodiment mainly contains magnesia spinel brick waste and a magnesia raw material as fireproof raw materials. The refractory raw material is the main raw material of the sprayed refractory composition. The fire-resistant raw material of the present embodiment may contain a commonly used fire-resistant raw material as an auxiliary component in addition to magnesia spinel brick dust and a magnesia raw material. The total content of magnesia spinel brick waste and magnesia raw material is 80% by mass or more, preferably 90% by mass or more, more preferably 95% by mass or more, and particularly preferably 100% by mass with respect to 100% by mass of the fireproof raw material. It is mass%.

<Magnesia spinel brick waste>
Magnesia spinel bricks are used in cement rotary kilns and secondary steel smelters. After use, magnesia spinel bricks (post-use products) are collected, crushed, and particle size adjusted, and can be used as refractory raw materials for sprayed fireproof compositions as magnesia spinel bricks. Grinding and particle size adjustment may be treatments generally used in the production of refractory raw materials.

The content of magnesia spinel brick dust is 10% by mass or more, preferably 40% by mass or more, more preferably 60% by mass or more, still more preferably 70% by mass, based on 100% by mass of the sprayed refractory composition. That is all. It is preferable because it has higher adhesiveness and less rebound loss.

<Magnesia raw material>
The content of the magnesia raw material is 0% by mass or more and 90% by mass or less, preferably 0% by mass or more and 60% by mass or less, and more preferably 0% by mass or more and 40% by mass or less with respect to 100% by mass of the sprayed fireproof composition. It is more preferably 0% by mass or more and 30% by mass or less. It is preferable because it has higher adhesiveness and less rebound loss. The magnesia raw material may be generally used as a refractory raw material, and examples thereof include natural magnesia, seawater magnesia, and fused magnesia. The purity of MgO as a raw material for magnesia is preferably 85% by mass or more. The corrosion resistance of the spray refractory composition can be improved.

<Total content of _{Na 2} O, K ₂ O, SO _{3 and Cl>}
A spray refractory composition consisting of magnesia spinel bricks after use in a cement rotary kiln with magnesia spinel bricks has improved adhesiveness and increased rebound loss reduction effect. _{Although the reason is not clear, the total content of impurities Na 2} O, K ₂ O, SO ₃ and Cl is suitable for the product after use in the cement rotary kiln, which contributes to the improvement of adhesiveness and the reduction of rebound loss. It is presumed that it is.

_{The total content of Na 2} O, K ₂ O, SO ₃ and Cl contained as impurities in magnesia spinel waste is 0.5% by mass or more and 5.0% by mass or less with respect to 100% by mass of magnesia spinel waste. It is preferably 1.0% by mass or more and 4.0% by mass or less, and more preferably 1.5% by mass or more and 3.0% by mass or less. It is preferable because it has higher adhesiveness and less rebound loss. In addition, since the product after use in the cement rotary kiln can be used, the sorting time and cost can be reduced, and the procurement can be facilitated. _{On the other hand, if the total content of Na 2} O, K ₂ O, SO ₃ and Cl contained in the magnesia spinel brick waste is too large, the corrosion resistance and abrasion resistance of the spray refractory composition may decrease.

The total content of Na ₂ O, K ₂ O, SO ₃ and Cl contained in the fire-resistant raw material is 0.2% by mass or more and 5.0% by mass or less, preferably 0.4% by mass, based on 100% by mass of the fire-resistant raw material. It is mass% or more and 4.0 mass% or less, more preferably 1.0 mass% or more and 3.0 mass% or less, and further preferably 1.2 mass% or more and 2.5 mass% or less. It is preferable because it has higher adhesiveness and less rebound loss. _{On the other hand, if the total content of Na 2} O, K ₂ O, SO ₃ and Cl contained in the refractory raw material is too large, the corrosion resistance and wear resistance of the spray refractory composition may decrease.

The total content of Na ₂ O, K ₂ O, SO ₃ and Cl contained in the spray fire resistant composition is 1.0% by mass or more and 5.0 mass% or less, preferably 1.0 mass% or less, based on 100 mass% of the spray fire resistant composition. Is 1.2% by mass or more and 4.0% by mass or less, more preferably 1.45% by mass or more and 3.0% by mass or less, and further preferably 1.8% by mass or more and 2.5% by mass or less. is there. It is preferable because it has higher adhesiveness and less rebound loss. On the other hand, _{if the total content of Na 2} O, K ₂ O, SO ₃ and Cl contained in the spray refractory composition is too large, the corrosion resistance and abrasion resistance of the spray refractory composition may decrease.

<Particle size distribution>
When the maximum particle size of the fireproof raw material is about 5 mm, the adhesiveness is higher and the rebound loss is small, which is preferable. The particle size distribution can be appropriately adjusted depending on the condition of the object to be repaired. For example, less than 5 mm and 3 mm or more (5 to 3 mm) are 15 to 40% by mass, and less than 3 mm and 1 mm or more (3 to 1 mm) are 15 to 45% by mass. Less than 1 mm, 0.3 mm or more (1 to 0.3 mm) can be 20 to 45% by mass, and less than 0.3 mm can be 25% by mass or less.

<Other raw materials>
The spray fire-resistant composition of the present embodiment contains fire-resistant clay, silicate, phosphate, carboxylic acid, carboxylic acid salt, sulfate, chloride, calcium hydrate, magnesium hydrate and the like as other raw materials. But it may be. Examples of the fire-resistant clay include water clay, kaolin, bentonite and the like. When the refractory clay is contained, the adhesiveness of the sprayed refractory composition is improved, and the rebound loss can be reduced. Examples of the silicate include lithium silicate, sodium silicate, potassium silicate and the like. The inclusion of silicate improves the wear resistance of the sprayed body. Examples of the phosphate include sodium phosphate, aluminum phosphate and the like. The inclusion of phosphate improves the wear resistance of the sprayed body. The carboxylic acid may be any one having a carboxyl group, and examples thereof include monocarboxylic acid, dicarboxylic acid, tricarboxylic acid, and oxycarboxylic acid. When the carboxylic acid is contained, the cohesiveness of the spray material can be adjusted and the rebound loss is reduced. Examples of the carboxylic acid salt include potassium salts, sodium salts, and aluminum salts of the carboxylic acids. When the carboxylate is contained, the cohesiveness of the spray material can be adjusted and the rebound loss can be reduced. Examples of the sulfate include magnesium sulfate and its hydrate, and examples of the chloride include magnesium chloride and its hydrate. In both cases, the adhesiveness of the sprayed refractory composition is improved. Examples of calcium hydrate include calcium hydroxide, Portland cement, and alumina cement hydrate. The inclusion of calcium hydrate improves the wear resistance of the sprayed body. Examples of magnesium hydrate include magnesium hydroxide and the like. The inclusion of magnesium hydrate improves the wear resistance of the sprayed body. These examples are examples, and are not limited to these. The total content of the other raw materials is preferably 10% by mass or less with respect to 100% by mass of the fireproof raw material. By setting the content to 10% by mass or less, the above effect can be more exerted.

Hereinafter, examples of the present disclosure will be described in detail.

<Experimental method>
A refractory raw material and other raw materials were mixed and kneaded with a V-type mixer for 15 minutes to produce a spray refractory composition, which was subjected to a spray experiment. Magnesia spinel brick waste after use in a cement rotary kiln and magnesia raw material were used as fireproof raw materials. Fire-resistant clay, sodium silicate, dicarboxylic acid, and calcium hydrate were used as other raw materials. The composition (mass%) of the magnesia spinel brick waste and the magnesia raw material is shown in Table 1, and the blending ratio (mass%) of the spray refractory composition is shown in Table 2.

The spraying experiment was conducted hot. Alumina-silica refractory was used for the sprayed surface. The surface to be sprayed was heated in advance with a heavy oil burner to adjust the surface to be sprayed to 800 ° C. A protector sprayer manufactured by Sayama Seisakusho Co., Ltd. was used as the sprayer. The tank capacity of ^{the sprayer was 0.2 m 3} , the spray pressure was 0.25 MPa, the size of the material hose was 10 m in length, the nominal diameter was 25 A, and the size of the nozzle was 1 m in length. A dry spraying method was adopted, and the added water was mixed with the sprayed refractory composition by a nozzle. The amount of added water was adjusted to 15 to 25% by mass with respect to 100% by mass of the sprayed refractory composition. The sprayed amount (M) of the sprayed refractory composition was 15 kg.

The following evaluations were made for the spraying experiment.

The degree of peeling was visually observed during spraying, and no peeling was evaluated as A, less peeling was evaluated as B, and more peeling was evaluated as C.

Further, the rebound mass (R) was measured after spraying, and the adhesive ratio (A) was calculated by the following formula.
A = (MR) ÷ M × 100
A spraying experiment was performed three times for each formulation, and the adhesion rate (%) was evaluated by the average value.

<Evaluation result>
The evaluation results are shown in Table 3.

In Comparative Examples 1 and 2 in which the amount of magnesia spinel brick waste was less than 10% by mass with respect to 100% by mass of the fireproof raw material, the degree of peeling was C and the adhesion rate was less than 80%. On the other hand, in Examples 1 to 7 in which the content of magnesia spinel brick waste was 10% by mass or more with respect to 100% by mass of the fireproof raw material, the degree of peeling was A to B, the adhesion rate was 80% or more, and the adhesiveness was good. Met. In Examples 2 to 3 and 6 to 7 in which the content of magnesia spinel brick waste was 40% by mass or more with respect to 100% by mass of the fireproof raw material, the degree of peeling was A, the adhesive rate was 82% or more, and the adhesiveness was particularly good. Met.

Although the present embodiment has been described in detail as described above, those skilled in the art will easily understand that many modifications that do not substantially deviate from the new matters and effects of the present disclosure are possible. Therefore, all such variations are within the scope of the present disclosure. For example, a term described at least once in the specification with a different term in a broader sense or synonymous can be replaced with the different term anywhere in the specification. Further, the configuration of the present embodiment is not limited to that described in the present embodiment, and various modifications are possible.

Claims (12)

Mainly contains magnesia spinel brick waste and magnesia raw materials as fireproof raw materials.
The purity of MgO as a raw material for magnesia is 85% by mass or more.
The content of the magnesia spinel brick dust is 10% by mass or more with respect to 100% by mass of the fireproof raw material.
The content of the magnesia raw material is 0% by mass or more and 90% by mass or less (excluding the case of 0% by mass) with respect to 100% by mass of the fireproof raw material.
A sprayed refractory composition, wherein the total content of the magnesia spinel brick dust and the magnesia raw material is 80% by mass or more with respect to 100% by mass of the fireproof raw material. Mainly contains magnesia spinel brick waste and magnesia raw materials as fireproof raw materials.
The content of the magnesia spinel brick dust is 10% by mass or more with respect to 100% by mass of the fireproof raw material.
The content of the magnesia raw material is 0% by mass or more and 90% by mass or less with respect to 100% by mass of the fireproof raw material.
When _{the total content of Na 2} O, K ₂ O, SO ₃ and Cl contained in the magnesia spinel brick waste is 0.5% by mass or more and 5.0% by mass or less with respect to 100% by mass of the magnesia spinel brick waste. A spray fireproof composition characterized by being present. Mainly contains magnesia spinel brick waste and magnesia raw materials as fireproof raw materials.
The content of the magnesia spinel brick dust is 10% by mass or more with respect to 100% by mass of the fireproof raw material.
The content of the magnesia raw material is 0% by mass or more and 90% by mass or less with respect to 100% by mass of the fireproof raw material.
The total content of Na ₂ O, K ₂ O, SO ₃ and Cl contained in the refractory raw material is 0.2% by mass or more and 5.0% by mass or less with respect to 100% by mass of the refractory raw material. Spray fireproof composition. Mainly contains magnesia spinel brick waste and magnesia raw materials as fireproof raw materials.
The content of the magnesia spinel brick dust is 10% by mass or more with respect to 100% by mass of the fireproof raw material.
The content of the magnesia raw material is 0% by mass or more and 90% by mass or less with respect to 100% by mass of the fireproof raw material.
The total content of Na ₂ O, K ₂ O, SO ₃ and Cl contained in the spray refractory composition is 1.0% by mass or more and 5.0% by mass or less with respect to 100% by mass of the spray refractory composition. A spray fireproof composition characterized by. In the spray refractory composition according to any one of claims 2 to 4.
A sprayed refractory composition, wherein the total content of the magnesia spinel brick dust and the magnesia raw material is 80% by mass or more with respect to 100% by mass of the fireproof raw material. The spray refractory composition according to any one of claims 1 , 3 to 5.
When _{the total content of Na 2} O, K ₂ O, SO ₃ and Cl contained in the magnesia spinel brick waste is 0.5% by mass or more and 5.0% by mass or less with respect to 100% by mass of the magnesia spinel brick waste. A spray fireproof composition characterized by being present. The spray refractory composition according to any one of claims 1 , 2, 4 to 6.
The total content of Na ₂ O, K ₂ O, SO ₃ and Cl contained in the refractory raw material is 0.2% by mass or more and 5.0% by mass or less with respect to 100% by mass of the refractory raw material. Spray fireproof composition. In the spray refractory composition according to any one of claims 1 to 3, 5 to 7.
The total content of Na ₂ O, K ₂ O, SO ₃ and Cl contained in the spray refractory composition is 1.0% by mass or more and 5.0% by mass or less with respect to 100% by mass of the spray refractory composition. A spray fireproof composition characterized by. In the method for producing a sprayed refractory composition in which magnesia spinel brick waste is mainly added as a refractory raw material and a magnesia raw material is added.
The purity of MgO as a raw material for magnesia is 85% by mass or more.
The content of the magnesia spinel brick dust is 10% by mass or more with respect to 100% by mass of the fireproof raw material.
The content of the magnesia raw material is 0% by mass or more and 90% by mass or less (excluding the case of 0% by mass) with respect to 100% by mass of the fireproof raw material.
The total content of the magnesia spinel brick waste and the magnesia raw material is 80% by mass or more with respect to 100% by mass of the fireproof raw material.
A method for producing a spray refractory composition, wherein the magnesia spinel brick waste is composed of magnesia spinel brick after use in a cement rotary kiln. In the method for producing a sprayed refractory composition in which magnesia spinel brick waste is mainly added as a refractory raw material and a magnesia raw material is added.
The content of the magnesia spinel brick dust is 10% by mass or more with respect to 100% by mass of the fireproof raw material.
The content of the magnesia raw material is 0% by mass or more and 90% by mass or less with respect to 100% by mass of the fireproof raw material.
When _{the total content of Na 2} O, K ₂ O, SO ₃ and Cl contained in the magnesia spinel brick waste is 0.5% by mass or more and 5.0% by mass or less with respect to 100% by mass of the magnesia spinel brick waste. Yes,
A method for producing a spray refractory composition, wherein the magnesia spinel brick waste is composed of magnesia spinel brick after use in a cement rotary kiln. In the method for producing a sprayed refractory composition in which magnesia spinel brick waste is mainly added as a refractory raw material and a magnesia raw material is added.
The content of the magnesia spinel brick dust is 10% by mass or more with respect to 100% by mass of the fireproof raw material.
The content of the magnesia raw material is 0% by mass or more and 90% by mass or less with respect to 100% by mass of the fireproof raw material.
The total content of Na ₂ O, K ₂ O, SO ₃ and Cl contained in the fire-resistant raw material is 0.2% by mass or more and 5.0% by mass or less with respect to 100% by mass of the fire-resistant raw material.
A method for producing a spray refractory composition, wherein the magnesia spinel brick waste is composed of magnesia spinel brick after use in a cement rotary kiln. In the method for producing a sprayed refractory composition in which magnesia spinel brick waste is mainly added as a refractory raw material and a magnesia raw material is added.
The content of the magnesia spinel brick dust is 10% by mass or more with respect to 100% by mass of the fireproof raw material.
The content of the magnesia raw material is 0% by mass or more and 90% by mass or less with respect to 100% by mass of the fireproof raw material.
The total content of Na ₂ O, K ₂ O, SO ₃ and Cl contained in the spray refractory composition is 1.0% by mass or more and 5.0% by mass or less with respect to 100% by mass of the spray refractory composition.
A method for producing a spray refractory composition, wherein the magnesia spinel brick waste is composed of magnesia spinel brick after use in a cement rotary kiln.