KR101952269B1 - Autoclaved light weight concrete composition using circulating fluidized bed combustion ash and method thereof - Google Patents

Abstract

The present invention relates to a lightweight foamed concrete composition using a circulating fluidized bed boiler ash and a method of manufacturing a lightweight foamed concrete block using the same. More particularly, the present invention relates to: (a) (b) mixing and agitating the hydrated algae with silica sand, quicklime, cement and water; (c) a step of casting and foaming; And (d) a step of curing; a method of producing a lightweight foamed concrete using a high-grade circulating fluidized bed boiler ash; And lightweight foamed concrete produced by the above method. The present invention has the effect of improving the utilization of industrial byproducts by establishing a method of hydration of a circulating fluidized bed boiler ash that has not been utilized as a conventional industrial by-product and can be used for manufacturing lightweight foamed concrete, The use of the gypsum used for concrete production is not required, and the amount of quicklime can be reduced, so that economical effects can be obtained. Further, the lightweight foamed concrete manufactured by the method of the present invention has an excellent compressive strength.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lightweight foamed concrete composition using a circulating fluidized bed boiler ash and a method of manufacturing a lightweight foamed concrete block using the same,

The present invention relates to a lightweight foamed concrete composition using a circulating fluidized bed boiler ash and a method of manufacturing a lightweight foamed concrete block using the same.

As the proportion of small cogeneration power increases, circulating fluidized bed boilers capable of producing energy with low calorific value are attracting attention. The circulating fluidized bed boiler uses low calorific value coal, and the higher the capacity, the higher the efficiency. Recirculating fluidized bed boilers are increasingly being adopted by refineries and power companies because they do not require separate desulfurization and denitrification facilities to reduce sulfur oxides emissions. In other words, limestone can be injected at the same time when fuel is supplied without a separate desulfurization facility, so that sulfur oxides generated during combustion can be discharged as ash.

Unlike general desulfurization gypsum, circulating fluidized-bed boiler ash is mixed with lime and gypsum. So desulfurization is a process of adding a lot of limestone, so ash is mixed with lime and gypsum.

On the other hand, since the plaster of Phosphoric Acid has been experiencing difficulties in supplying and receiving gypsum in Korea, efforts are being made to supply and receive gypsum. Efforts have been made to use circulating fluidized bed boiler ash in the field of gypsum use because the ash from the circulating fluidized bed boiler contains gypsum. However, there is a problem that a large amount of lime is added to the gypsum, And the like.

Therefore, it is necessary to develop a new technology that can apply circulating fluidized bed boiler ash to products using lime and gypsum simultaneously.

Korean Patent No. 10-1354249

Therefore, the inventors of the present invention confirmed that it is applicable to the production of lightweight foamed concrete as a recycling method of circulating fluidized bed boiler ash, which is an industrial by-product generated by desulfurization. By establishing a manufacturing method of high quality lightweight foamed concrete using circulating fluidized bed boiler ash Thereby completing the invention.

Therefore, it is an object of the present invention to provide a method of manufacturing a lightweight foamed concrete using a circulating fluidized bed boiler ash of a high-grade high-

Another object of the present invention is to provide a lightweight foamed concrete using a high-grade circulating fluidized bed boiler ash produced by the method of the present invention.

According to an aspect of the present invention, there is provided a method for producing a boiler ash, comprising the steps of: (a) hydrating a circulating fluidized bed boiler ash into an asteroid; (b) mixing and agitating the hydrated algae with silica sand, quicklime, cement and water; (c) a step of casting and foaming; And (d) curing. The present invention also provides a method for producing lightweight foamed concrete using the above-described high-fluidity circulating fluidized bed boiler ash.

In one embodiment of the present invention, the hydration of step (a) is performed by adding 1 to 3% by weight of K ₂ SO ₄ or Al ₂ (SO ₄ ) ₃ based on 100% by weight of the circulating fluidized bed boiler ash Followed by slurrying with stirring at a temperature of 15 to 25 DEG C for 3 hours to 7 days.

In one embodiment of the present invention, the hydrated alumina is mixed with 23 to 25 parts by weight of silica, 25 to 32 parts by weight of silica sand, 5 to 8 parts by weight of quicklime, 15 to 18 parts by weight of cement and 23 to 25 parts by weight of water .

을 기준으로 300~400g으로 첨가하여 수행하는 것일 수 있다.In one embodiment of the present invention, (c)

To 300 to 400 g based on the total weight of the composition.

In one embodiment of the present invention, the curing of step (d) is performed by first curing at a temperature of 45 ° C to 50 ° C for 3 to 5 hours and then curing at a temperature of 170 ° C to 190 ° C at a pressure of 9 to 11 atm Under conditions of 5 to 10 hours.

The present invention also provides a lightweight foamed concrete using a high-grade circulating fluidized bed boiler ash produced by the method of the present invention.

In one embodiment of the present invention, the hard foamed concrete may have a ratio of CaO / SiO ₂ of 0.5 to 0.9.

(A) hydrating a circulating fluidized bed boiler ash into an asteroid; (b) mixing and agitating the hydrated algae with silica sand, quicklime, cement and water; (c) a step of casting and foaming; And (d) a step of curing; a method of producing a lightweight foamed concrete using a high-grade circulating fluidized bed boiler ash; And lightweight foamed concrete produced by the above method. The present invention has the effect of improving the utilization of industrial byproducts by establishing a method of hydration of a circulating fluidized bed boiler ash that has not been utilized as a conventional industrial by-product and can be used for manufacturing lightweight foamed concrete, The use of the gypsum used for concrete production is not required, and the amount of quicklime can be reduced, so that economical effects can be obtained. Further, the lightweight foamed concrete manufactured by the method of the present invention has an excellent compressive strength.

FIG. 1 is a view showing a manufacturing process of a lightweight foamed concrete using a circulating fluidized bed boiler ash according to the present invention.
2 shows the results of measurement of compressive strength of lightweight foamed concrete using a circulating fluidized bed boiler ash produced by the method of the present invention.
FIG. 3 shows the results of measuring specific gravity of lightweight foamed concrete using a circulating fluidized bed boiler ash produced by the method of the present invention.
FIG. 4 shows a surface photograph of the manufactured lightweight foamed concrete according to the shape of a circulating fluidized bed boiler ash, wherein 4a is a circulating fluidized bed boiler ash in powder form, 4b is a circulating fluidized bed boiler ash in slurry form, To 9 show concrete produced while gradually increasing the addition amount of ash.
FIGS. 5 to 7 show results of analyzing degree of hydration according to kinds of additive and hydration time in the course of solidification of a circulating fluidized bed boiler ash.

The present invention is characterized in that a circulating fluidized bed boiler ash, which has not been utilized as an industrial byproduct, can be utilized in the production of lightweight foamed concrete.

Specifically, the method for producing lightweight foamed concrete using the circulating fluidized bed boiler ash provided by the present invention is characterized in that a circulating fluidized bed boiler ash is hydrated by blast furnace slag to form a slurry. Preferably, (a) hydrating a circulating fluidized bed boiler ash into an asteroid furnace; (b) mixing and agitating the hydrated algae with silica sand, quicklime, cement and water; (c) a step of casting and foaming; And (d) curing.

Generally, lightweight foamed concrete is manufactured by mixing raw materials other than lime and gypsum, and is excellent in heat insulation and sound insulation performance. In general, they are sold in the form of blocks and panels. Recently, eco-friendly materials have become popular, and users are greatly increasing. On the other hand, since the plaster in Korea has suffered from difficulty in supplying and receiving gypsum, there is a concern in industry due to concern about price increase due to lack of plaster.

Accordingly, the present inventors have established a process condition for producing lightweight foamed concrete while studying a method of reusing industrial byproduct ash from a circulating fluidized bed boiler as a circulating resource.

Particularly, the method of manufacturing the lightweight foamed concrete using the circulating fluidized bed boiler ash provided in the present invention first carries out the process of hydrating the circulating fluidized bed boiler ash to the blast furnace.

In the present invention, the ash is hydrated and used in an aesthetic stone because it can prevent the stability and sharpness during foaming and make the fine structure dense, thereby improving the compressive strength of concrete produced.

Particularly, in one embodiment of the present invention, lightweight foamed concrete manufactured by using an alumite (slurry), which is a hydrated form of a circulating fluidized bed boiler ash, and lightweight foamed concrete manufactured by using a circulating fluidized bed boiler ash, As a result, it was found that cracks occurred on the surface of the concrete using the powder form, and it was found that the stability of the shape was not secured. On the other hand, the lightweight foamed concrete using the water-hydrated alum-type concrete obtained by the method of the present invention secures the stability of the surface and shows that it has an anti-skid effect.

Therefore, in order to use the circulating fluidized bed boiler ash in the production of lightweight foamed concrete, it is very important that the process of hydration, ie slurrying, of the blast furnace is very important.

In addition, the hydration process according to the present invention can be carried out by adding 1 to 3% by weight of an additive based on 100% by weight of the circulating fluidized bed boiler ash and stirring the mixture. K ₂ SO ₄ or Al ₂ (SO ₄ ) ₃ can be used, and the use of the additive can shorten the time required for the secondary solidification.

After adding the K ₂ SO ₄ or Al ₂ (SO ₄ ) ₃ additive, the slurry is agitated at a temperature of 20 to 25 ° C for 3 to 7 days to solidify the circulating fluidized bed boiler ash.

As an additive in one embodiment of the present invention K ₂ SO ₄ or Al ₂ (SO ₄₎ was added to _3, was analyzed for yisuseok and generates the degree with time, the analysis result, Al ₂ (SO ₄₎ than K _{2 3} SO ₂ was higher than that of SO _4, and it was found that 3 hours after the hydration reaction was started. Al ₂ (SO ₄ ) ₃ was also found to be highly anisotropic in 6 hours, and it was found that the use of such an additive (accelerator) can effectively shorten the generation time of the alumite.

Therefore, the hydration can be stirred for 3 hours to 7 days, preferably 1 day to 7 days, and more preferably 1 day to 3 days so that sufficient hydration can be produced .

When the circulating fluidized bed boiler ash is hydrated in the blast furnace, the material for concrete production is mixed and agitated.

The above materials used for the production of lightweight foamed concrete are obtained by mixing hydrated alumite with silica sand, quicklime, cement and water.

Generally, in order to manufacture lightweight foamed concrete, gypsum should be used as a material, but in the present invention, a gypsum stone is used as a substitute for gypsum.

Preferably, the hydrated basement concrete comprises 23 to 25 parts by weight, 25 to 32 parts by weight of silica sand, 5 to 8 parts by weight of quicklime, 15 to 18 parts by weight of cement and 23 to 25 parts by weight of water, By weight.

On the other hand, the core technology of lightweight foamed concrete is to hydrothermally synthesize 11 Å Tobermorite, a type of calcium silicate hydrate, through hydrothermal reaction. Tobermorite is the result of hydrothermal synthesis and has a great influence on compressive strength which is one of important quality in lightweight foamed concrete. The hydrothermal reaction formula is as follows.

)와 규사(

), 물(

)을 재료로 고온 고압 조건에서 만들어지며, 토버모라이트 생성물의 절대적인 양이 압축강도와 비례한다. 즉 같은 단위 부피에서 토버모라이트의 양이 많이 생성이 되었다면, 압축강도 또한 크게 나타나게 된다. 이론적으로

몰비 (이하 C/S 몰비)가 0.83~1 사이에서 전량 반응을 하게 된다. 현재 경량 기포 콘크리트의 생산의 경우 C/S 몰비를 낮게 산정하여

성분이 반응을 전부할 수 있도록 하고

에 해당하는 규사 성분들은 잔존 반응물로서 남아있는 형태이다. 순환 유동층 보일러 애시를 사용하여 경량 기포 콘크리트를 제조하면 기존 대비 C/S 몰비에서 C에 해당하는

성분이 다량으로 들어가게 되면서 S에 해당하는

성분에서 추가된 양 만큼을 감소시켜 전체적인 C/S 몰비는 증가하게 된다. 따라서 잔존 반응물인 규사의 양을 감소되며 토버모라이트의 양은 증가되어 강도 증진 효과가 나타난다. In addition, such tobermorite may be used in the form of burnt lime

) And silica sand

), Water

), And the absolute amount of tobermorite product is proportional to the compressive strength. That is, if the amount of tobermorite is generated in the same unit volume, the compressive strength is also increased. Theoretically

(C / S molar ratio) is in the range of 0.83 to 1. Currently, the production of lightweight foamed concrete is based on a low C / S mole ratio

Allowing the components to react completely

Is the remaining form of the residual reactant. When the lightweight foamed concrete is manufactured using circulating fluidized bed boiler ash, the C / S molar ratio of C

As the ingredients are present in large quantities,

And the total C / S molar ratio is increased. Therefore, the amount of residual silica, silica sand, and the amount of tobermorite are increased to enhance the strength.

Accordingly, in light of the above, in the present invention, the lightweight foamed concrete using the circulating fluidized bed boiler ash is made of high quality concrete having excellent compressive strength, so that the silica, quicklime, cement and water are prepared by using the hydrated ash, By weight.

After the materials are mixed and the stirring process is completed as described above, the pouring and foaming processes are performed.

을 기준으로 300~400g으로 첨가하여 수행한다. Further, the above-mentioned pouring and foaming are carried out by mixing 1

Based on the total weight of the composition.

Lightweight foamed concrete is a porous material, which is a building material where pores account for 70% of the total volume. The uniformly well-distributed pores exhibit thermal insulation through the pores, which improves the compressive strength by making the stress dispersion uniform. In addition, foaming is a factor that has a great influence on the specific gravity of concrete, and concrete with low specific gravity can be produced by the effect of foaming. In the present invention, the aluminum powder was put into the final step of stirring to perform foaming, and the casting process was performed.

After completion of the foaming and casting process, the curing process is performed. In the present invention, the curing process is performed in two steps.

That is, the curing of step (d) is performed by first curing at a temperature of 45 ° C to 50 ° C for 3 to 5 hours and then at a temperature of 170 ° C to 190 ° C for 9 to 11 atm for 5 to 10 hours The second curing is performed to produce the lightweight foamed concrete according to the present invention.

As described above, the present invention can provide a lightweight foamed concrete using a circulating fluidized-bed boiler ash of a high-grade high-stiffness type. The lightweight foamed concrete of the present invention has a ratio of CaO / SiO ₂ 0.5 to 0.9.

The present inventors also analyzed the compressive strength and specific gravity of the lightweight foamed concrete produced by the method of the present invention. The lightweight foamed concrete produced in the present invention exhibited excellent compressive strength.

Therefore, the present invention can contribute to the enhancement of utilization of industrial by-products by establishing a new method for hydration of a circulating fluidized bed boiler ash that has not been utilized as a conventional industrial by-product and can be used for manufacturing lightweight foamed concrete, It is possible to reduce the amount of quicklime used, which contributes to the economical advantage.

Hereinafter, the present invention will be described in more detail with reference to Examples. These examples are for further illustrating the present invention, and the scope of the present invention is not limited to these examples.

≪ Example 1 >

Chemical Characterization of Circulating Fluidized Bed Boiler Ashes

The present inventors first analyzed the chemical properties of the circulating fluidized bed boiler ash before applying the circulating fluidized bed boiler ash to lightweight foamed concrete manufacture. The composition of ash was analyzed by XRD Rietveld quantitative analysis, and the constituent minerals and contents in ash are shown in Table 1 below.

Further, XRF analysis was performed to confirm the content of each element, and the results are shown in Table 2 below.

및

의 양을 확인함으로써 하기 실시예를 통해 제조한 제품의 C/S 몰비를 산정하는데 사용하였다.Through this analysis

And

To determine the C / S molar ratio of the product prepared through the following examples.

As a result of the analysis of the components contained in the circulating fluidized bed boiler ash, the detected components were identified as anhydrous gypsum, limestone, silica sand, calcium hydroxide and quicklime. Through the ratio of these components, in the present invention, And the percentage of quick lime was controlled.

≪ Example 2 >

Fabrication of Lightweight Foamed Concrete Using Circulating Fluidized Bed Boiler Ash

The present inventors have established a manufacturing process of lightweight foamed concrete of high quality by using a circulating fluidized bed boiler ash produced as a byproduct of a circulating fluidized bed boiler desulfurization in the production of lightweight foamed concrete. (1) Mixing quicklime, silica sand, cement and ash, (2) pouring and foaming, (3) primary curing and (4) secondary curing.

More specific preparation methods were prepared by the methods described below.

성분은 Ⅱ형 무수석고로 자연적으로 물과 반응하여

이수석고로 수화되는데, 자연적 수화는 오랜 시간이 소요되는 문제점이 있다. 이에 본 발명에서는 경량 기포 콘크리트 제조 시 이수석고를 사용하기 위하여, 부가적인 재료 및 복잡한 과정을 거치지 않고 단순히 교반을 통해 쉽고 빠르게 애시를 이수석고로 수화시켰고, 수화된 이수석고를 경량 기포 콘크리트의 제조에 사용하였다.Included in the circulating fluidized bed boiler ash

It is a type II anhydrous gypsum that naturally reacts with water

There is a problem that natural hydration takes a long time. Therefore, in the present invention, in order to use lightweight foamed concrete, the ash is easily and rapidly hydrated through the agitation without additional materials and complicated processes, and the hydrated water is used for the production of lightweight foamed concrete.

To this end, water and Al ₂ (SO ₄ ) ₃ or K ₂ SO ₄ as additives were added to 50 g of the circulating fluidized bed boiler ash in an amount of 1 g corresponding to 2% of the ash weight, respectively, and the stirring time was 1 minute Seconds at room temperature. The hydration reaction was performed for 7 days and the detection time of the algae was analyzed according to each age.

When the preparation of the flue gas using the circulating fluidized bed boiler ash was completed, the prepared flue gas (slurry), quicklime, silica sand, and cement were added and stirred. The agitation is carried out in the order of less influence on the heat. In order, ash slurry, water, silica sand, cement and quicklime are added in order and agitated. After the quicklime is added, the mixture is stirred for 3 minutes and 30 seconds, After that, the foundation of the manufacturing process was set up. The content of each component used for stirring is shown in Table 3 below, and the concrete prepared in the following Table 3 shows the production examples using K ₂ SO ₄ as an additive.

When the stirring process was completed, the casting and foaming process was performed. For foaming, 2343 g of aluminum powder was added for 30 seconds before the stirring was completed in the stirring step

After the foaming was completed, the curing process was carried out. The curing process was carried out in two stages. The first curing was carried out in a curing room at a temperature of 48 캜 for 3 hours, and after completion of the first curing, an autoclave curing was carried out at 180 캜 and 10 atm for 6 hours to obtain a circulating fluidized bed Lightweight foamed concrete using boiler ash was manufactured.

≪ Comparative Example 1 &

Lightweight foamed concrete was prepared in the same manner as described in Example 2, except that a slurry-type, circulating fluidized bed boiler ash without a slurry process was used instead of the slurry circulating fluidized bed boiler ash (Lee Sukseok).

<Experimental Example 1>

Performance Analysis of Lightweight Foamed Concrete Using Circulating Fluidized Bed Boiler Ashes According to the Present Invention

The performance of the lightweight foamed concrete prepared by using the slurry circulating fluidized bed boiler ash in Example 2 was analyzed. Performance was measured by compressive strength and specific gravity. The performance of compressive strength and specific gravity is analyzed based on the reference performance of the lightweight foamed concrete block proposed by KS F 2701. The evaluation criteria of KS F 2701 is shown in Table 4 below.

For reference, the difference between 0.5 and 0.7 indicates the difference in voids, which means that if 0.5 products are satisfied, other products can be manufactured. Therefore, the compressive strength and specific gravity of the concrete of the present invention were evaluated based on 0.5 parts in Table 4 above.

As a result of the analysis, as shown in Fig. 2, it was found from the compressive strength evaluation that all the products of Production Examples 1 to 4 prepared in the examples of the present invention can satisfy the strengths suggested by the KS standard, It was found that the reduced product showed higher strength than the product using gypsum.

As a result of the specific gravity analysis, the specific gravity of light-weather foamed concrete according to the present invention was not significantly different from that of lightweight foamed concrete using conventional gypsum, and it was in the range of 0.45 to 0.55 on the basis of 0.5 pieces, (See Fig. 3).

Accordingly, the inventors of the present invention have found that circulating fluidized bed boiler ash can be utilized as an industrial byproduct in the production of lightweight foamed concrete having high quality without using gypsum.

<Experimental Example 2>

Surface Analysis of Lightweight Foamed Concrete by Slurrying of Circulating Fluidized Bed Boiler Ash

The present inventors have found that in the production of lightweight foamed concrete using circulating fluidized bed boiler ash, slurrying of the circulating fluidized bed boiler ash, that is, the ash use of the hydrated ash blast furnace, is important, The surface of lightweight foamed concrete using fluidized bed boiler ash and lightweight foamed concrete using slurryed concrete were compared and analyzed.

As a result, as shown in FIG. 4, the lightweight foamed concrete produced by using the circulating fluidized bed boiler ash without powdering into the blast furnace was in the form of powder, cracks occurred on the surface, and the stability of the shape was not secured. And it was also found that the stability of prevention could not be secured. As the amount of the powder used increases, the surface stability becomes worse (see FIG. 4A).

On the other hand, the concrete using the slurry circulating fluidized bed boiler ash (Lee Soo Seok) showed surface stability (see FIG. 4B).

Therefore, it was found that it is very important to use recycled fluidized bed boiler ash for high quality lightweight foam concrete.

<Experimental Example 3>

Effects of Additive Type and Hydration Time on the Steam Solidification of Circulating Fluidized Bed Boiler ashes

In the previous examples, the present inventors measured the degree of hydration by hydration time using Al ₂ (SO ₄ ) ₃ or K ₂ SO ₄ as an additive in the solidification process of the circulating fluidized bed boiler ash, respectively.

As a result of the analysis, as shown in FIGS. 5 to 7, it was found that the use of Al ₂ (SO ₄ ) ₃ or K ₂ SO ₄ was faster than that of the group not using the additive (accelerator) In particular, the use of K ₂ SO _{4 shows} that the gypsum is accelerated more rapidly than that of the group using Al ₂ (SO ₄ ) _3. If these promoters are used, the productivity of the concrete can be further improved by shortening the reaction time And it was found.

In addition, in the group using K ₂ SO ₄ , it was found that the formation of the algae was started within 3 hours of the hydration reaction. In the group using Al ₂ (SO ₄ ) ₃ , .

Therefore, it was found that the hydration reaction should be performed for at least 3 hours when K ₂ SO ₄ is used as an additive, and the hydration reaction should be performed for at least 6 hours when Al ₂ (SO ₄ ) ₃ is used.

The present invention has been described with reference to the preferred embodiments. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Therefore, the disclosed embodiments should be considered in an illustrative rather than a restrictive sense. The scope of the present invention is defined by the appended claims rather than by the foregoing description, and all differences within the scope of equivalents thereof should be construed as being included in the present invention.

Claims (7)

(a) hydrating a circulating fluidized bed boiler ash in an admixture in slurry form;
(b) adding water, silica sand, cement and quicklime in order to the hydrated alum, mixing and stirring;
(c) a step of casting and foaming; And
(d) curing,
The hydration of step (a) may be performed by adding an additive of 1 to 3 wt% K ₂ SO ₄ or Al ₂ (SO ₄ ) ₃ based on 100 wt% of the circulating fluidized bed boiler ash, for 3 to 7 days Slurried at a temperature of 20 to 25 占 폚 while stirring,
The step (b) may be carried out by mixing and stirring 23 to 25 parts by weight of hydrated alginate, 23 to 25 parts by weight of water, 25 to 32 parts by weight of silica, 15 to 18 parts by weight of cement and 5 to 8 parts by weight of quicklime,
The curing of step (d) may be performed by first curing at a temperature of 45 ° C to 50 ° C for 3 to 5 hours and then curing at 170 ° C to 190 ° C for 9 to 11 atmospheres for 5 to 10 hours. Characterized in that a curing is carried out,
A Method for the Production of Lightweight Foamed Concrete Using High Flow Type Circulating Fluidized Bed Boiler Ash. delete delete The method according to claim 1,
(C) the pouring and foaming is carried out by mixing the stirred mixture 1 of step (b)

By weight based on the volume of the aluminum powder is added in an amount of 300 to 400 g. delete A lightweight foamed concrete using a recycled fluidised bed boiler ash produced by the method of claim 1. The method according to claim 6,
Wherein the lightweight foamed concrete has a ratio of CaO / SiO ₂ of 0.5 to 0.9.

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