JP6975220B2 - Manufacturing method of mortar, coke oven superstructure, and coke oven superstructure - Google Patents

Description

The present invention relates to a mortar, a coke oven superstructure, and a method for manufacturing a coke oven superstructure.

The coke oven has a structure in which a carbonization chamber for coking coal and a combustion chamber for supplying heat to the carbonization chamber are alternately connected. The heat from the combustion chamber is supplied to the carbonization chamber using the heat transfer of the brick, and the coal in the carbonization chamber is carbonized to produce coke. In such a coke oven, a large number of bricks are piled up to form a side wall (coke oven superstructure) that separates a carbonization chamber and a combustion chamber, and the furnace is built.

The coke oven is kept at a high temperature of over 1000 ° C. For this reason, the side wall of the coke oven (the upper structure of the coke oven) contains a large amount of silica stone (SiO ₂ ) that has relatively small volume change at high temperature, good thermal conductivity, and high mechanical strength. It is used.

Such silica stone bricks (hereinafter, also simply referred to as "brick") are joined by mortar.
However, in a coke oven, a temperature cycle is required for a long period of time due to operation, so if a mortar with a large volume change at the operating temperature is used, expansion and contraction are repeated, the strength of the mortar decreases, and there is a gap between the mortar and the brick. May occur and a gas leak may occur.
Therefore, for the coke oven, a mortar (silica stone mortar) containing silica _{stone (SiO 2} ) as a main component, which has characteristics that there is almost no thermal expansion and contraction at the operating temperature, is used. This prevents the strength from being reduced and the gap between the brick and the brick.

By the way, in the construction of a new coke oven, padd-up (retaining the existing foundation and constructing a new furnace) or partial transshipment repair, the work of constructing a brick (building a furnace) is enormous and requires a great deal of time.
Therefore, conventionally, a construction method called a module block construction method has been proposed (see, for example, Patent Document 1). The module block construction method is a construction method in which bricks are assembled into blocks (module blocks) of a predetermined size in advance outside the furnace, then the module blocks are transported to a coke oven and the module blocks are installed locally.
By adopting such a module block construction method, it is expected that the furnace construction period will be shortened.

In addition to the module block, there is a precast block manufactured by cast molding or vibration molding (see, for example, Patent Document 2).

When building a furnace using these blocks (module blocks, precast blocks), the upper and lower or left and right blocks are joined by mortar.
Hereinafter, the module block and the precast block may be collectively referred to as a “block”.

Japanese Unexamined Patent Publication No. 2001-19968 Japanese Unexamined Patent Publication No. 2013-189322

Mortars are generally required to have good workability. Specifically, for example, it is required that it can be applied to a brick or a block without clinging to a trowel, and that it can be applied to a vertical surface to a predetermined thickness.

In addition, mortar is required to have fluidity when joining bricks to each other.
However, normally, when a furnace builder stacks bricks and builds a furnace, the mortar does not lose its fluidity before the bricks are glued because another brick is glued immediately after applying the mortar to the bricks.

However, when joining blocks such as module blocks and precast blocks, large-scale equipment such as a crane is used. Therefore, the time from applying the mortar to the block to adhering another block is longer than usual. In this case, the mortar tends to lose its fluidity, so that the mortar and the block do not adhere to each other and the blocks do not join each other.

The present inventor presumed that the reason why the mortar loses its fluidity is that the water in the mortar is absorbed by the brick, and the water repellent is applied to the surface of the brick. However, the effect of suppressing the loss of liquidity of the mortar was not seen.

The present invention has been made in view of the above points, and an object of the present invention is to provide a mortar having excellent workability and maintaining fluidity.
Furthermore, an object of the present invention is to provide a coke oven superstructure using the above mortar and a method for producing the same.

As a result of diligent studies, the present inventor has found that the above object can be achieved by blending a specific amount of a cellulose derivative with a mortar, and has completed the present invention.

That is, the present invention provides the following [1] to [10].
[1] Contains a solid raw material, a cellulose derivative and water, and the content of the cellulose derivative is 0.1 part by mass or more and 2 parts by mass or less with respect to 100 parts by mass of the solid raw material, and the content of the water. However, the mortar is 23 parts by mass or more and 45 parts by mass or less with respect to 100 parts by mass in total of the solid raw material and the cellulose derivative.
[2] The mortar according to the above [1], wherein the content of the cellulose derivative is 0.2 parts by mass or more with respect to 100 parts by mass of the solid raw material.
[3] The mortar according to the above [1] or [2], wherein the content of the water is 30 parts by mass or more with respect to 100 parts by mass in total of the solid raw material and the cellulose derivative.
[4] The mortar according to any one of the above [1] to [3], wherein the cellulose derivative contains carboxymethyl cellulose.
[5] The mortar according to any one of [1] to [4] above, wherein the plastic viscosity is 30 Pa · s or more and 400 Pa · s or less.
[6] The mortar according to any one of the above [1] to [5], wherein the content _{of SiO 2 in the solid raw material is 80% by mass or more.}
[7] The mortar according to any one of the above [1] to [6], wherein the consistency measured according to JIS R 2506-1985 "Refractory mortar consistency test method" is 280 or more and 420 or less.
[8] The mortar according to any one of the above [1] to [7], wherein the adhesion time measured according to JIS R 2505-1981 "Adhesion time test method for fireproof mortar" is 15 minutes or more.
[9] A coke oven superstructure made by combining a plurality of at least one block selected from the group consisting of a module block and a precast block, and between the joint surfaces of the blocks, the above [1] to A coke oven superstructure in which the mortar according to any one of [8] is sandwiched.
[10] A method for manufacturing a coke oven superstructure, wherein a coke oven superstructure is manufactured by combining a plurality of at least one block selected from the group consisting of a module block and a precast block, and the coke oven superstructure is manufactured in one of the above blocks. A method for manufacturing a coke oven superstructure, wherein the mortar according to any one of [1] to [8] is applied and another block is repeatedly adhered.

According to the present invention, it is possible to provide a mortar having excellent workability and maintaining fluidity.
Further, according to the present invention, it is possible to provide a coke oven superstructure using the above mortar and a method for producing the same.

It is a perspective view which shows the fluidity test, and shows the state which the mortar was applied to the upper surface of the silica stone brick. It is a perspective view which shows the fluidity test, and shows the state which another silica stone brick was put on the coated mortar, and the compression load was applied. It is a perspective view which shows the manufacturing method of the coke oven superstructure.

[mortar]
The mortar of the present invention contains a solid raw material, a cellulose derivative and water, and the content of the cellulose derivative is 0.1 part by mass or more and 2 parts by mass or less with respect to 100 parts by mass of the solid raw material. The content of the mortar is 23 parts by mass or more and 45 parts by mass or less with respect to 100 parts by mass in total of the solid raw material and the cellulose derivative.

The mortar of the present invention is excellent in workability.
That is, when the mortar of the present invention is applied to bricks or the like using a trowel, it can be applied without clinging to the trowel and has good trowel release property.
Further, the mortar of the present invention has good vertical joint workability. Specifically, when the mortar of the present invention is applied to the side surface (vertical surface) of the brick, a predetermined thickness can be maintained and vertical joints can be easily constructed.

Further, the mortar of the present invention is also excellent in maintaining fluidity.
That is, when joining blocks such as module blocks and precast blocks, large-scale equipment such as a crane is used. In this case, for example, it takes 15 to 60 minutes from applying the mortar to the block to adhering another block.
The mortar of the present invention does not lose its fluidity even after a relatively long time (for example, 15 minutes or more) has passed since it was applied to bricks or the like.
Therefore, after applying the mortar of the present invention to a block, the mortar of the present invention maintains fluidity until another block is adhered, and the blocks can be satisfactorily bonded to each other.

Next, each component contained in the mortar of the present invention will be described in detail.

<Solid raw material>
The bricks, blocks and mortar used in the carbonization chamber and combustion chamber of a coke oven are preferably _{composed of SiO 2 as the main component.} This is because the spalling resistance is excellent at the operating temperature (about 600 ° C to about 1200 ° C) of the carbonization chamber or the like.
Therefore, in the mortar of the present invention, _{the content of SiO 2} in the solid raw material is preferably 80% by mass or more, more preferably 85% by mass or more, still more preferably 90% by mass or more. As a result, the spalling resistance is excellent at the operating temperature of the carbonization chamber or the like, and the adhesiveness to the block or the like can be maintained for a long period of time.

The components other than SiO ₂ are not particularly limited, and trace components may be adjusted according to the required characteristics such as strength.
Note that SiO ₂ is a notation (composition formula) as a chemical component, and as a raw material, for example, a pulverized product containing _{SiO 2 as a main component, such as silica stone brick, silica sand, and molten silica, can be used.} Examples of the components inevitably contained when these raw materials are used include Al ₂ O _{3 of} 2% by mass or less, CaO of 1% by mass or less, Na ₂ O of 0.5% by mass or less, and the like. Be done.

<Cellulose derivative>
The mortar of the present invention has a cellulose derivative content of 0.1 part by mass or more with respect to 100 parts by mass of a solid raw material. As a result, the mortar of the present invention is excellent in maintaining fluidity. Specifically, the time for maintaining the fluidity after applying the mortar is preferably 15 minutes or more.
As mentioned above, the reason why the mortar loses its fluidity is considered to be that the water in the mortar is absorbed by the brick. In the present invention, it is presumed that the cellulose derivative blended in the mortar reduces the moving speed of water in the mortar, so that the fluidity of the mortar is maintained.
The content of the cellulose derivative is preferably 0.2 parts by mass or more, and more preferably 0.3 parts by mass or more with respect to 100 parts by mass of the solid raw material, because the fluidity of the mortar can be maintained for a longer period of time.

On the other hand, in the mortar of the present invention, the content of the cellulose derivative is 2 parts by mass or less with respect to 100 parts by mass of the solid raw material. As a result, the mortar of the present invention does not have an excessively high plastic viscosity and is excellent in workability (troweling property).

By the way, if the upper and lower blocks are not joined, the upper blocks cannot be further stacked. For this reason, it is preferable that the fluidity of the mortar is not maintained for too long. Specifically, considering the cycle time at the time of installing the block, the time for maintaining the fluidity after applying the mortar is preferably 180 minutes or less.
The content of the cellulose derivative is 2 parts by mass or less and 1.5 parts by mass or less with respect to 100 parts by mass of the solid raw material because the time for maintaining the fluidity of the mortar is unlikely to be excessively long. It is preferably 0.8 parts by mass or less, more preferably 0.8 parts by mass or less.

Examples of the cellulose derivative include water-soluble cellulose derivatives such as methyl cellulose, carboxymethyl cellulose, methyl hydroxypropyl cellulose, hydroxyethyl cellulose, hydroxyethyl methyl cellulose, hydroxypropyl cellulose and cellulose sulfate ester.

Of these, the cellulose derivative preferably contains carboxymethyl cellulose because the mortar has better workability and the fluidity of the mortar is maintained for a longer period of time.
Carboxymethyl cellulose may be referred to as sodium carboxymethyl cellulose or CMC, which in the present invention means the same substance.
The viscosity of carboxymethyl cellulose when made into an aqueous solution may differ depending on the degree of etherification and the like, but the degree of etherification and the like are not particularly specified.

<Water>
The mortar of the present invention has a water content of 23 parts by mass or more with respect to 100 parts by mass in total of the solid raw material and the cellulose derivative. As a result, the mortar of the present invention is excellent in workability (troweling property) and also excellent in maintaining fluidity.
The water content is preferably 30 parts by mass or more, more preferably 34 parts by mass or more, based on 100 parts by mass of the total of the solid raw material and the cellulose derivative, because the fluidity of the mortar can be maintained for a longer period of time.

On the other hand, the mortar of the present invention has a water content of 45 parts by mass or less with respect to 100 parts by mass in total of the solid raw material and the cellulose derivative. As a result, the mortar of the present invention is excellent in workability (vertical joint workability).
The water content is 40 parts by mass or less with respect to 100 parts by mass in total of the solid raw material and the cellulose derivative because the consistency of the mortar does not become too large and the bonding time described later does not become too long. It is preferably 38 parts by mass or less, more preferably 38 parts by mass or less.

<Preparation method>
The mortar of the present invention can be obtained by appropriately mixing each of the above-mentioned components so as to have the above-mentioned content. The mixing method is not particularly limited, and a conventionally known method can be applied.

<Plastic viscosity>
The plastic viscosity of the mortar of the present invention is preferably 30 Pa · s or more because the bonding time described later is not too short.
On the other hand, the plastic viscosity of the mortar of the present invention is preferably 400 Pa · s or less because it is superior in workability (troweling property).

In the present invention, the plastic viscosity of the mortar is measured as follows.
As the viscometer, a co-axis double cylindrical rotary viscometer is used. The stress is measured by changing the rotation speed, and the plastic viscosity (= shear stress / shear rate) is obtained from the relationship between the shear rate and the shear stress.

<Consistency>
The consistency is the consistency measured according to JIS R 2506-1985 “Refractory Mortar Consistency Test Method”.
The consistency of the mortar of the present invention is preferably 280 or more because it is more excellent in workability (removability).
On the other hand, the consistency of the mortar of the present invention is preferably 420 or less because it is superior in workability (vertical joint workability).

<Adhesion time>
The bonding time is the bonding time measured according to JIS R 2505-1981 “Method for testing the bonding time of fireproof mortar”.
The adhesion time of the mortar of the present invention is preferably 15 minutes or more because it is superior in maintaining fluidity.
On the other hand, the bonding time of the mortar of the present invention is preferably 90 minutes or less, more preferably 80 minutes or less, because the time for maintaining the fluidity of the mortar is unlikely to be excessively long.

<Use>
The mortar of the present invention _{preferably contains bricks containing SiO 2} as a main component for joining a module block or a precast block.
_{The content of SiO 2 in} the brick or precast block in which the mortar of the present invention is used is preferably 80% by mass or more, more preferably 85% by mass or more, still more preferably 90% by mass or more.

[Manufacturing method of coke oven superstructure]
The method for manufacturing the coke oven superstructure of the present invention will be described with reference to FIG.
FIG. 3 is a perspective view showing a method of manufacturing the coke oven superstructure 15.
The coke oven 11 has a heat storage chamber 12, a plurality of combustion chambers 13 arranged above the heat storage chamber 12, and a carbonization chamber 14 arranged between adjacent combustion chambers 13.
A coke oven superstructure 15, which is a wall-shaped structure, is arranged between the combustion chamber 13 and the carbonization chamber 14, and is isolated from each other. That is, the spaces of the combustion chamber 13 and the carbonization chamber 14 are each defined by the coke oven superstructure 15.

The coke oven superstructure 15 is manufactured by combining (stacking) a plurality of refractories. As the refractory material, at least one block 16 selected from the group consisting of a module block and a precast block is used.
At this time, the above-mentioned mortar of the present invention is used for joining the blocks 16.
That is, the mortar of the present invention is applied to the block 16 and another block 16 is adhered repeatedly. In this way, the coke oven superstructure 15 in which the mortar of the present invention is sandwiched between the joint surfaces of the blocks 16 is obtained.

By the way, since the block 16 is large and heavy, it is moved by using a crane or the like. Therefore, the time from applying the mortar to the block 16 to adhering another block 16 is longer than usual.
However, even if it takes time to accurately stack the blocks 16 by operating a crane or the like, the fluidity of the mortar is maintained by using the mortar of the present invention, and good adhesion is achieved when the blocks 16 are joined to each other. Is possible.

Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to these.

<Preparation of mortar>
A solid raw material, carboxymethyl cellulose (CMC) which is a cellulose derivative, and water were mixed to obtain a mortar containing each of these components at the content shown in Table 2 below.
As the solid raw materials, the solid raw materials A to G shown in Table 1 below were used. In the solid raw materials A to G shown in Table 1 below, the fact that the total content of _{SiO 2 and Al 2} O ₃ is not 100% by mass is _{derived from the SiO 2} raw material and inevitably contains other components. Because it is.
The content of carboxymethyl cellulose (CMC) shown in Table 2 below is the content (unit: parts by mass) with respect to 100 parts by mass of the solid raw material.
The water content shown in Table 2 below is the content (unit: parts by mass) with respect to a total of 100 parts by mass of the solid raw material and carboxymethyl cellulose (CMC).

<Plastic viscosity>
The plastic viscosity (unit: Pa · s) of the obtained mortar was measured by the above-mentioned method. The results are shown in Table 2 below.

<Consistency>
The consistency of the obtained mortar was measured according to JIS R 2506-1985 “Refractory Mortar Consistency Test Method”. The results are shown in Table 2 below.

<Adhesion time>
The bonding time of the obtained mortar was measured according to JIS R 2505-1981 "Method for testing the bonding time of refractory mortar". The results are shown in Table 2 below.

<Workability>
The obtained mortar was applied to the upper surface (horizontal plane) of the silica stone brick with a thickness of 6 mm using a trowel, and further applied to the side surface (vertical surface) of the silica stone brick. At that time, the workability was evaluated as follows.

(Removability)
If the silica stone brick could be applied to the upper surface without the mortar clinging to the trowel, "○" was shown in Table 2 below, and if the mortar clung to the trowel, "x" was shown. If it is "○", it can be evaluated that the mortar has good trowel release property and excellent workability.

(Vertical joint workability)
Table 2 below shows "○" when the mortar could be applied to the side surface (vertical surface) of the silica stone brick with a thickness of 5 mm or more, and "x" when the mortar could not be applied with a thickness of 5 mm or more. If it is "○", it can be evaluated that the vertical joints are easy to construct and the workability is excellent.

<Maintaining liquidity>
The following fluidity test was performed on the obtained mortar in order to evaluate whether the fluidity was maintained after a predetermined time had passed from the application.

1 and 2 are perspective views showing a fluidity test, FIG. 1 shows a state in which mortar 3 is applied to the upper surface of silica stone brick 1, and FIG. 2 shows another silica stone on the applied mortar 3. The state where the brick 4 is put and the compression load is applied is shown.
First, as shown in FIG. 1, two spacers 2 having a thickness of 3 mm were arranged on the upper surface of the silica stone brick 1 having a size of 384 mm × 130 mm × 100 mm. The spacer 2 is a rectangular parallelepiped member. Spacers 2 were arranged one by one at both ends in the longitudinal direction on the upper surface of the silica stone brick 1. Then, using a trowel, mortar 3 was applied to the upper surface of the silica stone brick 1 to a thickness of 6 mm.
After a predetermined time has passed since the mortar 3 was applied, a silica stone brick 4 of the same size was placed on the mortar 3 as shown in FIG. 2, and 0.02 MPa was applied in the direction of the white arrow in FIG. The compression load of was applied. A compressive load of 0.02 MPa corresponds to the mass of a block having a height of 1 m.
When the mortar 3 flows by applying a compressive load and protrudes from between the silica stone brick 1 and the silica stone brick 4 and the thickness becomes 5 mm, "○" is displayed, and when the thickness does not reach 5 mm. Listed "x" in Table 2 below.

If the elapsed time after applying the mortar (“elapsed time after application” in Table 2 below) is 15 minutes or more and “○”, the fluidity is maintained even after a long time has passed since the application of the mortar. It can be evaluated that it is excellent in maintaining liquidity.

Unless otherwise specified, the above-mentioned tests and evaluations were carried out in a room controlled at a temperature of 20 ± 3 ° C. and a humidity of 60 ± 10%.

<Summary of evaluation results>
As is clear from the results shown in Table 2 above, the mortars of Comparative Examples 1 to 5 have insufficient workability and / or insufficient maintenance of fluidity, whereas the mortars of Examples 1 to 10 have insufficient workability. Was excellent in workability and also in maintaining fluidity.
More details were as follows.

The mortars of Comparative Examples 1 and 2 having too few cellulose derivatives maintained their fluidity insufficiently.
In Comparative Example 3 in which the amount of water was too small, the workability (troweling property) was insufficient, and the maintenance of fluidity was also insufficient.
In Comparative Example 4 in which the amount of the cellulose derivative was too large, the workability (troweling property) was insufficient.
In Comparative Example 5 in which the amount of water was too large, the workability (vertical joint workability) was insufficient.

Comparing Examples 1 to 10, the content of the cellulose derivative is 0.2 parts by mass or more with respect to 100 parts by mass of the solid raw material, and the content of water is 100 parts by mass in total of the solid raw material and the cellulose derivative. On the other hand, the mortars of Examples 5 to 7 and 9 to 10 having 30 parts by mass or more can secure 30 minutes or more as the elapsed time from application (elapsed time after application) in the fluidity test, and flow. It can be evaluated that the sex can be maintained for a longer period of time.

<Making and installing blocks>
The silica stone brick used for the coke oven superstructure defining the combustion chamber and carbonization chamber of the coke oven was assembled into a module block having a size of about 6 m × 0.9 m × 1.5 m. Four of these module blocks were prepared. Four module blocks were joined using the mortar of Example 7 (horizontal direction: 2 units, height direction: 2 units). It took a maximum of 65 minutes from the start of application of the mortar to the adhesion of the module blocks, but the fluidity of the mortar was maintained and the bonding was good.

In addition, 16 silica stone precast blocks having a size of about 4 m × 0.9 m × 1.5 m were prepared. Using the mortar of Example 5, 16 precast blocks were joined (horizontal direction: 4 units, height direction: 4 units). It took a maximum of 50 minutes from the start of application of the mortar to the adhesion of the precast block, but the fluidity of the mortar was maintained and the bonding was good.

The coke oven superstructure using these blocks continues to operate well without gas leaks from the joints.

1: Silica stone 2: Spacer 3: Mortar 4: Silica stone 11: Coke furnace 12: Heat storage chamber 13: Combustion chamber 14: Carbonization chamber 15: Coke furnace superstructure 16: Block

Claims (7)

Contains solid raw materials, cellulose derivatives and water,
The cellulose derivative is carboxymethyl cellulose.
The content of the cellulose derivative is 0.2 parts by mass or more and 2 parts by mass or less with respect to 100 parts by mass of the solid raw material.
The content of the water is 23 parts by mass or more and 35 parts by mass or less with respect to 100 parts by mass in total of the solid raw material and the cellulose derivative .
The content of SiO ₂ prior Symbol solid material is 80 mass% or more, mortar. The mortar according to claim 1, wherein the content of the water is 30 parts by mass or more with respect to 100 parts by mass in total of the solid raw material and the cellulose derivative. The mortar according to claim 1 or 2 , wherein the plastic viscosity is 30 Pa · s or more and 400 Pa · s or less. The mortar according to any one of claims 1 to 3 , wherein the mortar having a consistency measured according to JIS R 2506-1985 "Refractory mortar consistency test method" is 280 or more and 420 or less. The mortar according to any one of claims 1 to 4 , wherein the adhesion time measured according to JIS R 2505-1981 "Adhesion time test method for fireproof mortar" is 15 minutes or more. A coke oven superstructure made by combining a plurality of at least one type of blocks selected from the group consisting of module blocks and precast blocks.
The coke oven superstructure in which the mortar according to any one of claims 1 to 5 is sandwiched between the joint surfaces of the blocks. A method for manufacturing a coke oven superstructure, which comprises combining a plurality of at least one block selected from the group consisting of a module block and a precast block to produce a coke oven superstructure.
A method for manufacturing a coke oven superstructure, wherein the mortar according to any one of claims 1 to 5 is applied to one block, and another block is repeatedly adhered to the block.

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