KR20190020232A - Composition for solidifying ground using biomass ash - Google Patents

Abstract

The present invention relates to a solidification agent composition using biomass ash. The solidification agent composition using biomass ash includes: 35-45 wt% of portland cement; 35-45 wt% of slag fine powder; 2.5-15 wt% of fly ash; 2.5-15 wt% of petro cokes flue-gas desulfurized gypsum; and 3-15 wt% of an inflation agent. Therefore, the solidification agent composition using biomass ash can prevent volume contraction phenomenon which can occur when a middle layer ground or a deep layer ground is improved. Moreover, the solidification agent composition can prevent environmental pollution and can reduce disposal costs for waste generated when industrial by-products are disposed of. According to the present invention, the solidification agent composition using the biomass ash can obtain an excellent level of intensity of the ground and can reduce manufacturing costs. In addition, the solidification agent composition can reduce the disposal costs for waste, consumed when the industrial by-product is disposed of and can protect environment by preventing the possibility of environmental pollution, which can occur when the waste is disposed of, in advance.

Description

Solidifying agent composition using biomass ash {COMPOSITION FOR SOLIDIFYING GROUND USING BIOMASS ASH}

The present invention relates to a hardener composition using biomass ash.

In general, when improving the middle layer or deep layer of the ground, a technique of increasing the strength of the ground by mixing the ground and the solidifying agent by using a SCW (soil cement wall) method or a deep cement mixing (DCM) method has been utilized, Korean Patent Publication No. 10-1614309 discloses a technology related to the SCW method.

These ground reforming methods use cement and water to be injected into the soft ground during the construction of the ground.However, in the case of cement milk with a cement flow value of 180mm, the water content ratio , Water content / powder weight) is very high (1.5 ~ 2.4), the volume shrinkage phenomenon may occur seriously as the water is discharged except for the combined water during curing of the solidifying agent, which causes voids between the structure and the ground, resulting in ground strength There was a possibility of deterioration.

Therefore, there is a need for the development of a technique for preventing the volume shrinkage caused by the cement milk state of the injection material during the improvement of the middle layer or deep ground.

On the other hand, as the recent reduction of fossil energy and greenhouse gas reduction due to the response to the climate change convention have emerged, the Renewable Energy Portfolio Standard (RPS) has been mentioned as an eco-friendly policy to reduce carbon dioxide emissions. Renewable energy mandatory allocation is a system that requires a certain percentage of the total generation of power generation companies and the total sales of sales companies to be supplied or sold to renewable energy sources. must do it.

In other words, the relevant companies must directly introduce renewable energy generation facilities or purchase renewable energy certificate (RE) from other renewable energy generation companies to meet the mandatory quota. The usage of is increasing and expanding.

Therefore, existing power plants are preparing for the construction of biomass fuel-only power plants to secure more renewable energy supply certificates, and many biomass power plants are expected to be established in the future.

However, since biomass-based power generation methods burn biomass as fuel, biomass incineration is generated as an industrial by-product in the process, and when landfilled for disposal of biomass incineration, waste treatment costs may be excessively generated. In addition, there was a possibility that it would act as another cause of environmental pollution.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object thereof is to provide a technique for preventing a volume shrinkage phenomenon that may occur when the middle layer or the deep ground is improved.

In addition, the present invention has another object to provide a technology for reducing the waste disposal costs and prevent environmental pollution caused by the disposal of industrial by-products.

The problem to be solved by the present invention is not limited to the above-described problem, other technical problems that are not mentioned will be clearly understood by those skilled in the art from the following description.

In one aspect of the present invention, the solidifying agent composition using the biomass ash to achieve this object is usually 35 to 45% by weight of Portland cement; 35 to 45 wt% fine slag powder; Fly ash 2.5-15% by weight; Petroleum coke flue gas desulfurization 2.5 to 15% by weight; And 3 to 15% by weight of an expanding agent.

In addition, the swelling agent may be provided with a biomass ash.

The fly ash may be provided with at least one of pulverized coal fly ash and a circulating fluidized layer fly ash.

In addition, the slag fine powder may be provided as blast furnace slag fine powder.

In addition, the petroleum coke flue gas desulfurization gypsum may be prepared by the flue gas desulphurized gypsum generated in a circulating fluidized bed boiler using a petrol coke as fuel.

In addition, the biomass ash may be provided with at least one of flooring and fly ash which are residues generated by the combustion of the biomass.

Here, the biomass may be provided with at least one of woody and non-woody biomass.

In addition, the biomass may be provided with at least one selected from the group consisting of wood pellets and wood chips.

Means for solving the above problems are merely exemplary and should not be construed as limiting the present invention. In addition to the exemplary embodiments described above, there may be additional embodiments described in the drawings and detailed description of the invention.

As described above, the present invention has the following effects.

First, the present invention is rapidly absorbed by the hydration reaction of the calcium oxide and magnesium oxide of the chemical components contained in the biomass ash, the volume of calcium hydroxide and magnesium hydroxide produced by the hydration reaction is expanded so that the middle layer Alternatively, the strength of the ground can be secured to an excellent level by minimizing the volume shrinkage that may occur when the deep ground is improved.

Second, the present invention may further promote the initial hydration reaction of the blast furnace slag powder and fly ash using calcium oxide and strong alkaline materials (eg, potassium oxide, sodium oxide) which are chemical components contained in the biomass ash.

In other words, it is possible to reduce the manufacturing cost because the initial strength can be secured to an excellent level by accelerating the initial hydration reaction without reducing or using the existing strong alkaline crude steel material, which is expensive.

Third, the present invention can be used as a solidifying agent composition by recycling slag fine powder, pulverized coal fly ash, circulating fluidized bed fly ash, petroleum coke flue gas desulfurization gypsum, biomass ash, which are inevitably generated in industrial processes. The disposal cost of waste by-products can be reduced and the environment can be protected by preventing the possibility of environmental pollution.

The effects of the present invention are not limited to the above-mentioned effects, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

Preferred embodiments of the present invention will be described in more detail below, but the technical parts that are well known will be omitted or compressed for brevity of description.

The solidifying agent composition according to one embodiment of the present invention usually includes an Ordinary Portland Cement, Slag Powder, Fly Ash, Petro Cokes Desulfurization Gypsum and an Expanding Agent. can do.

In one embodiment, usually portland cement may be added for strength of the hardener. In general, when Portland cement is made of strong alkali, calcium ion in cement accelerates ion exchange rate with strong alkali ions (e.g. Na, K, etc.), so that it dissolves well in water and generates hydrate (i.e., dissolution precipitation reaction). As the rate is increased, an early increase in strength may be achieved due to an increase in the rate of hydration of the cement.

Portland cement according to one embodiment may be included in 35 to 45% by weight. If the Portland cement is less than 35% by weight, the initial and long-term strength of the solidifying agent may be poor, which may make it unsuitable for use in middle or deep construction. The unit price rises, and the hydration reaction of the cement can be rather inhibited by the organic matter in the soil, and the excessive use of cement is not only an environmental problem by discharging a large amount of carbon dioxide during cement production, but also depleting resources such as limestone. It is preferable to be carried out within the above-mentioned range because it causes.

Slag fine powder usually forms ettringite crystals upon contact with portland cement, and various kinds of slag fine powder can be applied. For example, the slag fine powder may be classified into a blast furnace slag fine powder, a converter slag fine powder, or the like, depending on the generation position.

The slag fine powder used in the embodiment is a blast furnace slag fine powder, the blast furnace slag fine powder has a latent hydraulic properties, and the curing properties of the slag may be weak due to the stimulation of the alkaline substance.

More specifically, the blast furnace slag fine powder is a latent hydraulic material formed of glass such as silicon (Si) or aluminum (Al). When the blast furnace slag fine powder is reacted with water, calcium oxide (CaO) in the blast furnace slag fine powder is eluted, and silicon, aluminum and calcium ions in the glassy body are dissolved and precipitated to perform a hydration reaction. However, since the hydration reaction is stopped as the impermeable film is generated on the particle surface during the initial reaction, when the alkaline ions are supplied from the outside, the hydration reaction can be easily performed while the impermeable film is destroyed.

The blast furnace slag fine powder according to one embodiment may be included in 35 to 45% by weight. If the blast furnace slag fine powder is less than 35% by weight, the long-term strength and durability may be lowered. If the content of the blast furnace slag fine powder exceeds 45% by weight, the initial reaction rate is lowered, and an alkaline substance is used for smooth hydration. Since the workability is deteriorated because it must be added in an excessive amount, the content of the blast furnace slag fine powder is preferably applied within the above range.

In one embodiment, fly ash replaces a portion of ordinary portland cement that is added to a solidifying agent, thereby solving environmental problems such as carbon dioxide generation and resource depletion problems due to excessive use of cement. It can improve the strength and durability.

The fly ash according to an embodiment may be provided with at least one of pulverized coal fly ash and a circulating fluidized bed fly ash (CFBC Ash). Pulverized coal fly ash and circulating fluid bed fly ash is calcium silicate by the pozzolanic reaction monohydrate (Calcium-Silicate-Hydrate, CSH ; 3CaO · 2SiO 2 · 3H 2 O) and calcium aluminum silicate hydrate (Calcium-Aluminum-Silicate Hydrate, CASH; 2CaO · Al ₂ O ₃ · SiO ₂ · 8H ₂ O) contributes to the development of strength of the solidifying agent.

In particular, since the circulating fluidized bed fly ash is generated in a circulating fluidized bed boiler that mixes coal and limestone, it is richer in calcium oxide than pulverized coal fly ash, and the calcium oxide is converted to calcium hydroxide (Ca (OH) ₂ ) by a hydration reaction. Higher levels of intensity development are possible.

Here, the pulverized coal fly ash refers to fly ash generated when the pulverized coal, which is a form in which coal is pulverized to a predetermined size, is burned in a boiler.

In addition, in one embodiment, the circulating fluidized bed fly ash refers to fly ash generated in a circulating fluidized bed boiler using at least one of bituminous coal and petroleum coke as fuel. Fly ash, such as pulverized coal fly ash or circulating fluidized bed fly ash, may be collected by a separate dust collector installed in the boiler.

In one embodiment, the pulverized coal fly ash and the circulating fluidized bed fly ash may be included in an amount of 2.5 to 15 wt%, respectively. If the content of the fly ash is less than 2.5% by weight, there is a fear that the reduction effect and the watertightness of cement use by the fly ash may be lowered. If the content is more than 15% by weight, the initial strength is lowered, and the amount of the alkaline material is injected. This increase may cause a problem of increase in manufacturing cost, so it is preferably carried out within the above-mentioned range.

In one embodiment, the petroleum coke flue gas desulfurization gypsum produces a needle-like ettringite crystal, usually through hydration with portland cement and blast furnace slag powder, and the resulting ettringite dense and harden the tissue of the hydrate to form condensation. To promote and improve initial strength.

In addition, a large amount of sulfur trioxide contained in the petroleum coke flue gas desulfurization gypsum may contribute to the initial strength improvement by reacting with the blast furnace slag fine powder.

Petro coke flue gas desulfurization gypsum according to an embodiment may be applied to the flue gas desulfurization gypsum generated in a circulating fluidized bed boiler using a petrol coke as fuel. Petroleum coke flue gas desulfurization gypsum contains higher calcium oxide than conventional desulphurized gypsum because it is generated during the mixing of fuel and limestone for desulfurization in the furnace of the circulating fluidized bed boiler. Calcium oxide contained in a large amount of petroleum coke flue gas desulfurization gypsum can be converted into calcium hydroxide in the hydration reaction, and high levels of strength can be expressed.

In addition, the petroleum coke flue gas desulfurization gypsum in one embodiment may be included in 2.5 to 15% by weight. If the petroleum coke flue gas desulfurization gypsum is included in less than 2.5% by weight, the initial reaction rate is lowered, and when it exceeds 15% by weight, the initial strength is not improved compared to the amount of excess. It is desirable

In one embodiment, the swelling agent is added to minimize volume shrinkage due to evaporation of free water during middle or deep construction of the ground, and may be applied as a biomass ash (BMA).

In general, the middle layer and the deep mixing method inject the cement milk depending on the hydraulic pressure up to 100 ~ 500m of the rubber tube formed with a diameter of 40 ~ 50mm, so that the flow value is formed very high, the water content ratio of the powder content is 1.5 ~ 2.5 Is maintained.

In other words, the existing method has a high unit quantity of water, and when cured, shrinkage may occur severely due to evaporation of free water (ie, water other than bound water). Voids between the and solidifiers can cause adverse effects on the structure.

However, in an embodiment of the present invention, conventional mass and depth methods are used by adding biomass ash, which is rich in calcium oxide and magnesium oxide, to a solidifying agent, and using a volume expansion phenomenon that occurs during the hydration reaction of calcium oxide and magnesium oxide. It can solve the shrinkage phenomenon that is a problem.

Biomass ash according to an embodiment may be provided with at least one of the biomass bottom ash (biomass bottom ash) and biomass fly ash (burn mass) generated by the combustion of the biomass, the biomass ash 3 It may be included in the 15% by weight.

If the content of biomass ash is less than 3% by weight, it is difficult to sufficiently secure the expansion effect due to biomass ash, so it is difficult to prevent the volume shrinkage during the construction of the ground, which may lower the strength of the ground. If it exceeds, since the crack of the ground may occur due to excessive expansion of the cement milk injection material, it is preferable to add the expansion material within the above-described range that can compensate for the shrinkage of the cement during curing of the hardener.

Biomass according to an embodiment may be provided with at least one of woody and non-woody biomass. Here, the wood-based biomass may include wood pellets, sawdust, wood chips, waste wood, and the like.

In addition, the non-wood biomass in the present specification means a kind other than the wood-based biomass of the known biomass, sorghum, crests, sunflower, bamboo, silver grass, EFB (empty fruit bunches), FFB (fresh fruit bunches) ), As well as herbaceous biomass such as corn stalk, palm kernel shell, rice hull and reed, as well as organic waste such as food waste, livestock manure and seaweed biomass.

On the other hand, in another embodiment, the biomass ash may be applied to the collection of incineration ash generated when burning at least one selected from the group consisting of wood pellets and wood chips, in which case the incineration ashes produced by burning different kinds of biomass. Compared with calcium oxide and magnesium oxide may contain a lot.

First, in order to confirm this, 20 kg of wood pellets (product name: wood pellets (main ingredient-acacia wood), manufacturer: AVP, country of origin: Vietnam) are put into the inside of the heating furnace, and 6-8 hours at a temperature of 850-900 ° C. Wood pellets were burned, and fly ash generated during combustion was collected and analyzed by X-Ray Flourescence Spectrometry (XRF). The component results of the biomass ash using wood pellets are shown in Table 1 below.

As shown in Table 1, it can be confirmed that fly ash generated by burning wood pellets, which is one of the types of biomass, contains a large amount of calcium oxide component and magnesium oxide component.

Hereinafter, the present invention will be described in more detail through specific preparation examples. The following preparation examples are only one example to help understanding of the present invention, and thus the scope of the present invention is not limited or limited thereto.

Common Portland cement (Product name: OPC, Manufacturer: Dongyang Cement), blast furnace slag fine powder (Gwangyang Works), pulverized coal fly ash (Taean thermal power plant), circulating fluidized bed fly ash (Gunsan Gunjang Energy Power Plant) , The density of petroleum coke flue gas desulfurization gypsum (Gunsan Gunjang Energy Power Plant) was measured by KS L 5110 (specific gravity test method of cement), and each powder level was tested by KS L 5106 (Powder cement test by air permeation device). Method), the composition of the chemical composition of each input material was measured by XRF analysis, details are as described in Table 2 below.

Based on the components shown in Table 2 to prepare a solidifying agent composition of each Preparation Example and Comparative Example, the solidifying agent was formulated according to the numerical value shown in Table 3. In Table 3 below, the dosage unit for each component is g (gram), and BMA is the same component as the biomass ash of Table 1.

NO. OPC SP FA CFBC Ash PCDG BMA Comparative Example 1 45 45 10 Comparative Example 2 40 40 20 Comparative Example 3 35 35 30 Comparative Example 4 34 34 13 2 16 One Comparative Example 5 34 34 16 12 2 2 Comparative Example 6 40 39 One One 16 3 Comparative Example 7 40 36 3 One 17 3 Comparative Example 8 33 17 16 17 One 16 Comparative Example 9 32 16 17 16 2 17 Preparation Example 1 45 45 5 5 Preparation Example 2 40 40 10 10 Preparation Example 3 35 35 15 15 Preparation Example 4 45 45 5 5 Preparation Example 5 40 40 10 10 Preparation Example 6 35 35 15 15 Preparation Example 7 45 45 5 5 Preparation Example 8 40 40 10 10 Preparation Example 9 35 35 15 15 Preparation Example 10 45 45 2.5 2.5 5 Preparation Example 11 40 40 5 5 10 Preparation Example 12 35 35 7.5 7.5 15 Preparation Example 13 45 45 2.5 2.5 5 Preparation Example 14 40 40 5 5 10 Preparation Example 15 35 35 7.5 7.5 15 Preparation Example 16 45 45 2.5 2.5 5 Preparation Example 17 40 40 5 5 10 Preparation Example 18 35 35 7.5 7.5 15 Preparation Example 19 44 44 3 3 3 3

A solidifying agent was prepared based on the formulation of each component of Comparative Examples 1 to 9 and Preparation Examples 1 to 19, but was prepared by mixing with water according to KS L 5109 to prepare a strength sample. Compressive strength at room temperature (25 ℃) was measured using a compressive strength tester. Compressive strength measurement results for the strength samples of Comparative Examples and Preparation Examples are as described in Table 4 below. In Table 4, the strength units of the Comparative Examples and Preparation Examples are MPa.

NO. 3 days strength 7 days strength 28 days strength Comparative Example 1 13.4 22.7 42.7 Comparative Example 2 12.1 23.4 41.6 Comparative Example 3 10.3 19.6 38.1 Comparative Example 4 11.4 18.5 38.5 Comparative Example 5 10.1 19.4 39.4 Comparative Example 6 12.4 20.5 39.7 Comparative Example 7 12.8 22.4 39.1 Comparative Example 8 9.9 17.5 38.5 Comparative Example 9 10.0 17.1 39.5 Preparation Example 1 14.1 23.5 41.8 Preparation Example 2 13.3 23.8 40.8 Preparation Example 3 10.8 20.1 36.8 Preparation Example 4 14.5 23.9 42.5 Preparation Example 5 13.3 24.4 42.1 Preparation Example 6 11.7 20.2 36.5 Preparation Example 7 14.3 23.4 43.5 Preparation Example 8 13.2 24.1 42.8 Preparation Example 9 12.0 19.5 35.4 Preparation Example 10 14.3 23.4 42.1 Preparation Example 11 13.0 24.1 42.6 Preparation Example 12 10.9 20.0 36.5 Preparation Example 13 14.1 23.3 36.6 Preparation Example 14 13.9 23.5 41.9 Preparation Example 15 11.1 18.5 36.5 Preparation Example 16 14.1 24.4 40.1 Preparation Example 17 13.5 23.1 40.5 Preparation Example 18 11.4 20.8 35.2 Preparation Example 19 14.4 24.1 43.2

As described in the compressive strength measurement results of Table 4, Preparation Examples 1 to 19, in which portland cement, blast furnace slag fine powder, pulverized coal fly ash, circulating fluidized bed fly ash, petroleum coke flue gas desulfurization gypsum and biomass ash are formulated at appropriate levels, Compared with Comparative Examples 1 to 9 it can be confirmed that the overall initial strength and long-term strength was expressed at an excellent level.

In addition, through the compressive strength measurement results of Comparative Examples 4 to 9, when the content of each component contained in the solidifying agent composition exceeds or less than the input range of each component, it can be confirmed that the initial strength and long-term strength expression is not good.

As a result, the present invention absorbs moisture present in the ground rapidly by the hydration reaction of calcium oxide and magnesium oxide, which are chemical components contained in the biomass ash, and expands the volume of calcium hydroxide and magnesium hydroxide produced by the hydration reaction, thereby forming a middle layer. Alternatively, the strength of the ground can be secured to an excellent level by minimizing the volume shrinkage that may occur when the deep ground is improved.

That is, the three-day strength and the seven-day strength of the solidifying agent composition using the biomass ash are increased by 10 to 35% compared to the solidifying agent without the biomass ash, and the 28-day strength is comparable. There is a sustained effect.

In addition, during the middle and deep construction, the conventional volumetric shrinkage tends to be about 10 to 15%, but the solidifying agent composition according to an embodiment of the present invention has a shrinkage rate of 3 to 10% due to the use of biomass ash. Can be reduced.

On the other hand, the solidifying agent composition according to an embodiment of the present invention is mainly used in the middle layer or deep construction, and has a distinctive feature from the solidifying agent for sewage sludge treatment whose main purpose is to reduce the water content of the sludge.

The solidifying agent used in the general middle or deep construction site should be formed on the cured solidifying agent at the early stage of construction so that the subsequent process can be continued continuously. This is very important and requires high strength development compared to solidifying agents for sewage sludge treatment.

That is, the present invention is a soil reinforcing agent composition for reinforcing the strength of the ground by improving the original soil with high moisture content or water inflow, so that not only the reduction of moisture content but also the initial strength and long-term strength are usually maintained at an excellent level. Cement, fine slag powder, pulverized coal fly ash, circulating fluidized bed fly ash, petroleum coke flue gas desulfurization gypsum and biomass ash may be included as main components.

In addition, the present invention may further promote the initial hydration reaction of the blast furnace slag fine powder and fly ash by using calcium oxide and strong alkaline materials which are chemical components contained in the biomass ash.

That is, the chemical composition of the biomass ash is present in about 40% by weight of calcium silicate hydrate, which is the main hydrate of cement, and calcium oxide, which forms calcium hydroxide, so that stable strength can be expressed, and biomass ash contains strong alkali materials (eg, , K ₂ O, Na ₂ O) is also present, so the initial strength of the slag powder can be stimulated by stimulating the fine powder of slag without reducing or using the existing high alkaline crude steel, which can secure the initial strength to an excellent level. The manufacturing cost can be reduced.

In other words, the present invention is to stimulate the fly ash and blast furnace slag fine powder using a large amount of calcium oxide and alkaline materials contained in the biomass ash, thereby overcoming the low initial strength, which is a disadvantage of the existing solidifying agent, By solving the problem of the existing solidifying agent used to shrink the phenomenon of magnesium oxide as a swelling agent component, there is an effect to improve the ground hard when the moisture is introduced into the ground due to the high soil or civil engineering work.

In addition, the present invention can be used as a solidifying agent composition by recycling the slag fine powder, pulverized coal fly ash, circulating fluidized bed fly ash, petroleum coke flue gas desulfurization gypsum, biomass ash which are inevitably generated in industrial processes. The disposal cost of waste by-products can be reduced and the environment can be protected by preventing the possibility of environmental pollution.

As described above, the detailed description of the present invention has been made by the embodiments with reference to the accompanying table. However, since the above-described embodiments have only been described with reference to preferred examples of the present invention, the present invention is limited to the above embodiments. It should not be understood that the scope of the present invention is to be understood by the claims and equivalent concepts described below.

Claims (8)

Usually 35-45% by weight of Portland cement;
35 to 45 wt% fine slag powder;
Fly ash 2.5-15% by weight;
Petroleum coke flue gas desulfurization 2.5 to 15% by weight; And
3 to 15% by weight of the expanding agent; characterized in that it comprises a
Solidifying agent composition using biomass ash. The method of claim 1,
The expanding agent is characterized in that the biomass ash
Solidifying agent composition using biomass ash. The method of claim 1,
The fly ash is characterized in that at least one of pulverized coal fly ash and circulating fluidized bed fly ash.
Solidifying agent composition using biomass ash. The method of claim 1,
The slag fine powder is characterized in that the blast furnace slag fine powder
Solidifying agent composition using biomass ash. The method of claim 1,
The petroleum coke flue gas desulfurization gypsum is characterized in that the flue gas desulphurized gypsum generated in a circulating fluidized bed boiler using a petroleum coke as fuel
Solidifying agent composition using biomass ash. The method of claim 2,
The biomass ash is characterized in that at least one of the bottom ash and fly ash which is a residue generated by the combustion of the biomass.
Solidifying agent composition using biomass ash. The method of claim 6,
The biomass is characterized in that at least one of woody and non-woody biomass
Solidifying agent composition using biomass ash. The method of claim 7, wherein
The biomass is characterized in that at least one selected from the group consisting of wood pellets and wood chips
Solidifying agent composition using biomass ash.