WO2014185625A1

WO2014185625A1 - Geopolymer mix design method

Info

Publication number: WO2014185625A1
Application number: PCT/KR2014/002103
Authority: WO
Inventors: 이수정; 주형태; 진철민; 강남희; 조성백
Original assignee: 한국지질자원연구원
Priority date: 2013-05-16
Filing date: 2014-03-13
Publication date: 2014-11-20
Also published as: WO2014185625A8; KR101399952B1; CN105228971A; CN105228971B

Abstract

The present invention relates to a geopolymer mix design method. The geopolymer mix design method according to the present invention for determining the mixing ratio of a geopolymer prepared by mixing a basic material containing an aluminosilicate component, an alkaline activator and water comprises: a material analysis step for selecting a basic material and an alkaline activator and analyzing the chemical composition; a basic calculation step for calculating the respective number of moles of Si, Al, Na and H per unit weight of the materials; a target setting step for setting standard values with respect to main factors including the Si/Al molar ratio and the Na/Al molar ratio in the finally prepared geopolymer; and a mixing ratio calculation step for calculating, on the basis of the result calculated at the basic calculation step, the mixing ratio of respective materials so as to meet the standard values of the main factors, which are set at the target setting step, in a mixture obtained by mixing the materials.

Description

[Specification ϊ

[Name of invention]

Geopolymer formulation design method

【Field of Energy】

The present invention relates to a technology for construction and geoplymers, and particularly to a method for designing a geopolymer composition that can optimize the mixing ratio of each component of the geopolymer.

[Background Gas, 3 Geopolymer] is an inorganic binder that hardens in low silver only by chemical reaction between aluminosilicate raw material and alkali activator. Since the production of geopolymers does not require a firing process, the energy consumption required for production is much lower than that of the Forland sheet, and carbon dioxide emissions can be reduced by more than 80%.

However, that scientific approach to geo-polymers are concerned only the industrial utilization of the right in a state that is not backed by systematic field-oriented research has been directed to perform gyeolgoe ^■ Geo a dreamer 'precise conceptual agreement also buggy firing weapons without for the binder It is mixed in a broad sense. Geopolymer of the correct concept refers to a material having amorphous properties as being made of a raw material having pozzolanicity among the inorganic binders which are reacted with an alkali activator 3: That is, fly ash, flooring, metacarlin, and soda-lime glass in thermal power plants. Jill Semant, natural pozzolanics, briquettes and the like can be used as raw materials for georeamers. However, when blast furnace slag is used as the main raw material, it is conceptually not a geoplasmer because CSH galls similar to the Semanite Mall are produced as the main reactants.

As mentioned above, research on geopolymers has been biased around immediate applicability. Most geopolymers research papers focus on studying the change in compressive strength after reaction by increasing the molar concentration of alkali activator constant regardless of chemical composition or properties of raw materials. For example, in the case of coal ash, which is a raw material of geopolymer, the reaction properties against alkali are very different depending on the combustion conditions of coal, the type and content of minerals contained in coal ash, the size and shape of particles, and the storage condition of coal ash. The physical properties of geopolymers are determined by many different conditions besides the concentration of alkali activator. However, he studies geoplymers on an empirical basis without scientifically identifying the factors that determine the properties and reactivity of geoplymers. Based on the empirical formulation, geopolymers made using strong alkalis are not only consistent in quality, but also have safety problems due to the use of excess alkali, and the manufacturing cost is high. For example, if a lot of strong alkali is used, excess Nat will remain in the pore SQkltlOR, and over time, sodium will react with carbon dioxide in the air, causing eif iorescence on the surface of the geopolymer. .

Therefore, scientific analysis of factors influencing the properties of geopolymers is required, and it is necessary to prepare a standardized method for designing a geopolymer blend based on this. Detailed description of the invention

[Technical problem]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and sets in advance the reference values of the factors affecting the properties of the geo «reamer, and premixes the blending ratio of the raw materials to allow the geopolymer to be produced that can satisfy this reference value. The purpose is to provide a geopolymer formulation design method that can be calculated.

【Esoteric Solution】

Geo-polymer-fold ¾ ^'design method according to the present invention for achieving the above object, as for determining the baehapbieul of geo polymer are prepared by mixing the base material containing the Al luminometer silicate component, an alkali activator and water A raw material analysis step of selecting a basic raw material and an alkali reactivator »and analyzing the chemical composition; A basic calculation step of calculating the moles of each of Si, Al, Na and H per unit weight of the basic raw material, shallow cal activator and water; Si / A in the final geopolymer produced! A target setting step of setting reference values for key factors that determine the properties of the geopolymer, including the molar ratio and the Na / Al molar ratio; And based on the result calculated in the basic calculation step, the basic raw material _: in the mixture containing the alkali activator and water, the basic raw material and alkali may satisfy the reference values of the main factors set in the target setting step. Characterized in that made, including; compounding ratio calculation step of calculating the respective compounding ratio for the activator and water.

Advantageous Effects According to the present invention, the method of designing the blender of the geopolymer may satisfy the set values of the Si Ml ratio, the a / Al ratio and the water content ratio, which are factors which have a significant influence on the physical properties of the geopolymer. It provides a method to calculate the blending amount of geol reamer raw materials.

This provides a more scientific and systematic approach to geopolymer formulations and provides a foundation for active research into the structure and properties of geopolymers using specimens prepared from formulation designs according to the major factors of geopolymers. ᅳ In addition, through the scientific blending design according to the present invention, it is possible to improve the economics of using raw materials, and to enjoy stability problems such as the whitening of the produced geopolymer. E ΪΪ -i- s. ¾ ·: 1 ΑΛ "1.

The present invention is expected to contribute to the geopolymer industry by providing the most important and basic data on the properties of geopolymers.

Brief description of the drawing]

I is a schematic flow diagram of a geopolymer formulation design method according to an embodiment of the present invention.

Figure 2 is a table showing the use of the geopolymer according to the Si / ratio-. 3 is a table showing the design data and the result data of the experiment for the present invention,

It is a table which shows the chemical composition of the sample (filled coal ash) of FIG.

5 is a graph of the quantitative X-ray diffraction analysis results for the sample. 6 is an amorphous component analysis result of the landfill coal material of Seocheon Thermal Power Plant calculated from X-fluorescence spectroscopy and quantitative X-ray diffraction analysis.

Figure 3 is a graph showing the compressive strength of geopolymer made under the conditions shown in Figure 3,

8 (a) to 8 (c) are photographs of blood-sections observed with a gaze-cell ^■ microscope for three samples.

9 is a photograph taken with scanning electron micrographs of fracture surfaces of four georeamer ¾ samples.

[Best form for implementation of the invention]

Geopolymer blending design method according to the present invention for achieving the above object, to determine the blending ratio of the geopolymer produced by mixing a basic raw material containing an aluminosilicate component, an al ¾ reactivator and water as, dicing material analysis step of analyzing the chemical composition by selecting the base material ⁷ i and the alkaline activator; Singh-ki basic raw materials. Si. Per unit weight of alkali activator and water. A basic calculation step of calculating the number of moles of each of Al, Na, and H; Si / A in the final geopolymer produced! A third step of setting reference values for key factors that determine the properties of the geopolymer, including the mo! E ratio and the Na / Al molar ratio; And based on the result calculated in the basic calculation step, the basic raw material, alkali may satisfy the reference value of the main factor set in the target setting step in the mixture containing the basic raw material, alkali activator and water. Comprising the step of calculating the respective compounding ratio for the activator and water: consisting of It is characterized by.

According to the present invention, it is preferable that the main factor for determining the characteristics of the geopolymer in the target setting step further includes a water content ratio.

In addition, in the raw material analyzing step, pretreatment is performed to remove unburned carbon powder from the basic raw material, and in the basic calculating step, only Si, Al are present in the amorphous part except for the crystalline part of the basic raw material. It is preferred to calculate the respective moles for, Na and H.

In particular, the singular-base calculation step is Si, Al, Na. In order to calculate the content of H, the contents of Ai ₂ 0 ₃ , Si¾ _' Na ₂ 0, ¾0 contained in the basic raw materials, additives, and water, respectively, were determined, and then, Si, Al _; It is preferable to calculate the sum of the moles of Na and H.

_And> the basic calculation step, after the analysis of the Si / Al molar ratio of the base material and Ma / Ai molar ratio, the target setting standing phase control I member of the Si l molar ratio reference value in the SI / A1 molar ratio of the basic ¾ fee Higher? It is preferable to set the degree low.

In one embodiment of the present invention _{> In} selecting the sodium aluminate as the alkali activator in the alkali selection step, the front-to-acid sodium powder in the solid state is selected.

[Form for implementation of invention]

Hereinafter, a geopolymer composition design method according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. 1 is a schematic flowchart of a geo ¾ reamer formulation design method according to an embodiment of the present invention-.

Geopolymer formulation design method according to an embodiment of the present invention (¾αοο) is to determine the relative blending ratio of ^· , alkali activator and mole of the base material raw materials of the geopolymer, as shown in FIG. It comprises a pretreatment step (10), raw material analysis step (20), basic calculation step (30), target setting step (40), compounding ratio calculation step (40).

In the present invention, first select the basic raw material and alkali activator of the geopolymer, and performs the raw material analysis step αω to analyze their chemical composition,

The basic raw material of the geopolymer is composed of aluminosilicate components and is a material having pozzolanic properties. Materials that can be used as basic raw materials include fly ash, bottom ash, coal briquettes, etakaol inj and natural pozzolanic ash (pumice or volcanic ash) from thermal power plants. It is submerged in water and activated by an alkali activating agent.

Alkali activator is a basic substance that reacts with coal landfill. Nath hydroxide f (NaOH). Water glass (N Si ᅳ H ₂ 0), Sodium aluminate powder (NaAK ^), Sodium aluminate solution (NaAi 'n¾0 ). Alkaline foaming agents can be used singly. You may use it in two or more plurality. In this example, two alkali activators were used. After selecting the base material with an alkaline activator performs pre-processing for the main raw ^material, pre-treatment is di to the above to crush the coal methoxy ripjae a suitable particle size and to remove the non-drawn ^tansobun, however, the tansobun content of unburnt coal in the buried material If low, the pretreatment may be omitted. There are various methods for removing unburned carbon dust, such as the flotation of the flotation. The flotation method ¹ is one of the beneficiation methods, which utilizes the difference in hydrophobicity and hydrophilicity of the mineral surface. It is a method of selectively attaching hydrophobic mineral particles to an air bubble to separate them. That is, coal-filled land with a fluid is injected into a tank, and a collecting agent and a foaming agent are injected, and when bubbles are blown, bubbles adhere to unburned carbon powder. It floats to the surface of the tank and can remove unburned carbon powder from coal landfill.

After the pretreatment, ^■ analyze the chemical composition of the alkali activator of the coalfill material. Identifying what is contained in the coal filler and the alkali activator is essential for the scientific design of geopolymer. Chemical composition analysis of the basic raw material and alkali activator Si, Al, Na. This is linked to the process of identifying the H's mobilizer. Si, Al, Na. Of basic raw material and alkali activator. Since H does not exist in pure atomic form but in oxide form such as Si¾, Α1-, ¾, Ν 0, 0, the composition ratio of this oxide must be determined first in the raw material analysis step (Κ ⁾ . The composition ratio of the above oxides in the raw material and the alkali activator can be determined by various methods, such as the X ^™ fciy flourescene spectrometer as in this embodiment Can be identified through side equipment,

Importantly, the composition ratio of the above oxides is not exaggerated for the entire coal landfill material, but only for the amorphous part of the coal landfill material except for the crystalline material. This is because the presence of these materials as crystalline makes no sense in the formulation design because they do not participate in geopolymer reactions with alkalinizers.

For example, SK) ₂ contained in coal continuum is common in crystallinity and crystalline. After analyzing the total Si () ₂ content by XRF, the crystalline Si¾ content is determined by XRD again. Since the difference between these two values is the amorphous SI0 ₂ content, only these values are used for the calculation of the blender. And the composition ratio of sodium hydroxide or alumina soda solution among al¾ reactivators is already known. For example, two moles of NaOH each contain one mole of Ν¾0 and ¾0.

As described above, the basic calculation step 20 is performed based on the chemical composition analysis of the coalfill material and the alkali activator which are the basic raw materials. In the basic calculation step (20) calculates the content of Si, Al, Na, H per unit weight of the base material.

Since the composition of the oxide in the raw material analysis step (10) is a complete crocodile for the state, the content of Si, Al, Ma, fl per unit weight of the basic raw material can be easily calculated through a mathematical calculation considering the chemical formula of each oxide. ᅳ Here, the content means the number of moles or increase of the silicon, aluminum, sodium, and hydrogen components. The deformation between weight and mole number is simple with the atomic weight known, so any unit can be used. Do. In this embodiment calculates the number of moles of each component per unit weight coal ash _merip, will be briefly described, for example, within the embedding material coal. Assuming that 40 wt% of ¾ is mixed, 1 kg of coal landfill contains 400 g of Si.

Since the molecular weight of ¾ is 14 and the atomic weight of oxygen is 8 (16 because it formed oxygen molecules),

The increase of Si is about 400x (W / 30) = 86.6g. Divide by 14, the atomic weight of ¾ silicon, to 13.2 moles. That is, the number of moles of silicon contained in 1 kg of coal landfill is 13.2.

In addition, the basic calculation step (20) is based on the calculation of the number of moles of each component in the base material ^, Si / A! The molar ratio and the Na / Al molar ratio can be calculated and used later in the target setting step. This will be described later.

After determining the number of moles per unit weight of silicon, aluminum, nat, and hydrogen in the basic raw material through the basic calculation step ( ⁾ , the reference values for the main factors of the geopolymer to be finally prepared in the batch setting step (30) Set.

Geopolymers include Si0 ₄ and Ala; Oxygen atoms alternately share in the tetrahedron to form a network structure. That is, A! Is substituted for Si in a continuous SiO., Tetrahedron structure. Since Si has a tetravalent charge while Ai has a trivalent charge, a monovalent bivalent silver such as sodium (Na) or potassium (K) is further formed.

The ratio SI / A1 and Na / Al of geopolymers are important for structural warming. It has a meaning and acts as a major factor in determining the properties of the geoplymer. here

Si / Al ratio or Na / Al ratio means molar ratio, but the weight ratio can be used because it knows the atomic weight of silicon, aluminum and sodium.

As described in the prior art, the existing studies have been biased only for the characteristics of compressive strength depending on the variation of strength according to the diversification of alkali ^activator or the concentration of alkali ¾ agent. Accordingly, the present invention has been conceived based on the main themes that constitute the core concept of the geometrical structure of the geopolymer, such as Si / Ai ratio, Na / Al ratio in the geoplymer, specifically, the basic raw material, alkali activator In the formulation of water, a method of preliminarily setting a reference value for the above-mentioned main factors and calculating a compounding ratio of raw materials that can satisfy the reference value is chemically and mathematically developed.

The meaning of having a Si / Al bur is complex, but if the molar ratio of Si / AI is less than 3.0, the compressive strength of the geopolymer becomes large, and if it exceeds 3,0, it has flexible elasticity. Accordingly, as shown in FIG. 2 _: the use of the geopolymer may vary according to a Si / Al molar ratio as a building material, an adhesive S, a sealant, or a resin material. In this example, the Si / Al rates were set to 2.0, 2.5, 3.0, and the like.

The Na / Al ratio is important for the stability of geopolymers ^. Lose. If the Na content is excessive due to the excessive use of the alkali activator, Na, which does not participate in the reaction, remains in the geopolymer and combines with carbon dioxide in the air, causing whitening of the geopolymer. Theoretical Na / Al Ratio Considering Chemical Structure

II Should be 1, but experimental results of the inventors confirmed that bleaching occurs even when A and A1 are in a 1: 1 ratio. In this example, the Na / M ratio is set to ¾ above 1, such as 0.8. In addition, the water content has a great influence on the flow (ow) of the geopolymer and is an important factor in the working rate and the curing rate.

Therefore, in the present invention, after setting the reference value for the water content during the Si / Al ratio Na / Al ratio and geo-polymer blending in the target setting step ⁽ 30), the relative value of the basic raw material, alkali activator and water to satisfy this reference value The amount of lilies will be determined.

When the determination of the main factors of the geopolymer is completed, the compounding ratio calculation step 40 calculates by the mathematical method in which proportion the base material, the alkali activator and the water should each be mixed. As will be described later in the experimental example, in this embodiment, the geopolymer was blended by mixing two kinds of alkali activator and water in coal-filled materials, and the Si per unit weight of coal-filled materials and two alkali activators and water, The moles of Al, Na and H have already been calculated in the basic calculation step (20).

In the compounding ratio calculation step (40), the coal landfill bran calculated in the basic calculation step (20), two alkali activators and Si _: Al, Na. Ingot for H confiscation · Si / A! Selected in target setting step (30) Values for the ratio, a / Ai ratio and water content rate can be used to calculate the amount of coalfill, two alkali activators and water in a mathematical manner. More specifically, to know the Si, Ma, AI and the water content included in each gyeryo, because it is finally determined that the ratio to obtain the _status, it is possible seeul linear equations to mathematically the matrix form, each through which The blending amount of the materials can be determined. Mathematically, each material obtained through calculation increases the applicability in the field by expressing the increase ratio.

As described above, after determining the weight ratio of each material, some adjustments can be made to the water content. That is, after confirming the actual dough kneading by using the water content obtained in the compounding ratio calculation step 40, the water content can be modified in a certain range in consideration of workability. The water content can be determined in the range of approximately 20-25 increments ¾. That the acceleration -I- content obtained from the L ^(4. Q) Hefei calculation step means that the hydrogen content in the bovine and sat geo polymer varies. However, the addition of water does not affect the Si i ratio and Na / Al ratio, which are the main factors of the geopolymer in the present invention, so that the flowability of the geopolymer is adjusted to the desired level. It is desirable to match

As described above, in the present invention, the Si / Al ratio, Na / Al ratio and water content of the finally prepared geopolymer are determined in advance. In order to meet this standard, it is possible to determine the mixing ratio of the four raw materials.

The inventors have geo replicon Murray mix design method consisting of the above-described configuration ^■ developed to record computer programs made up of computer ¾ deche form. This computer program calculates the final blended weight ratios for the four raw materials given the input data. Is displayed by

In other words, the user inputs data on the ratio of 3: sex ratio (weight ratio) of SiO ,, Ai ₂ 0 ₃ , Na ₂ 0, ¾0 for the four raw materials: basic raw material, two alkali activators and water. Enter the Si / Al molar ratio _> Na / Al molar ratio ， water content of the geopolymer.

In the computer program, the formula for calculating the content of Si, Al, Na, in Si¾, Al ₂ 0 _St Na, 0, ¾Q, the change equation for the increase and the molar number, and the matrix for mathematically solving the compounding ratio are included. . The computer program uses the data to mathematically calculate the blending ratio of the four raw materials (compound ratio calculation step). In the outermost longitudinal computer displays the four blending weight ratio of the raw material ^■ monitor. The present inventors developed a computer program as described above, and then analyzed the composition of the actual coal landfill material and alkali activator, the target Si / Al ratio, Na! The experiment was performed to obtain the blending ratio of the four raw materials by refraining the ratio of rain and water. Hereinafter, the experimental example will be described.

In this experiment, we measured and calculated the amounts of semi-male aluminum and silicon that could react with alkali in buried coal ash at Seocheon Thermal Power Plant. In addition, the composition ratio was calculated to control the chemical composition of the geopolymer to be prepared and the flowability of the raw material mixture. Geo-reamer Si / Al burs to 2,0, 2.5 and 3.0 The relationship between the compressive strength and the microstructure of geoplymer was tested when various alkali activators were used.

1. Experimental method

The sample used as the raw material of geopolymer in this experiment is landfill coal discharged from Seocheon thermal power plant. The landfill coal ash is mainly buried with seawater in the landfill due to the mixing of large-size retent ash among the bottom ash and fly ash of the thermal power plant. After the samples were collected and dried naturally for 3 days, the cone and quarter sampling method was used by using a shovel after convection, and the large particles and the particles were mixed evenly, and 20 kg were taken. As a result of industrial analysis, the unburned carbon was removed by the flotation method due to the high unburned carbon content. As a collector used to increase the hydrophobicity of the surface of unburned carbon powder and selectively attach it to the foam, kerosene is used as a foaming agent to keep the air bubbles attached to the unburned carbon powder without being put out. irother) I used pine oil-,

The unburned carbon content of samples and flotation was analyzed by a co- analyzer (TGA 601, Leco Corp., US). Unburned carbon was removed from the sample using a rod mill (rod miii). Quantitative X- ray diffraction analysis of the sample is attracted to ⁷ discrete i ⁵ teubeop was used ^{DIFFMC 'T0PAS 4.2 (Bruker-AXS} , Gern iiy) software. Internal standard material Cakkim Fluoride (CaF _2l 99.985%, Aifa) was added 10wt% of sample weight. X-ray diffraction analysis was performed using a D8 Advance diffractomeer (Bruker ~ AXS, Germany) with Cu target and LynxEye position sensitive detector. Diffraction patterns were obtained with ¾ cases of 5 ^° to 95 ° 2Θ, 0.0Γ step size, 1 sec per step, and 0.3 ^° divergence s! It and 2.5 ^"' solar slit were used. .

For the standardization of the quantitative tunite and instrumental parameters of the sample, two X-ray stripe patterns were obtained for the sample and the standard sample (La, SRM 660b _; NiS ^' f, US) in the same case. The chemical composition of the samples was analyzed by X-ray fluorescence spectrometer (X Ray Floiirescence Spectrometer, Shi mad zu Sequent iai XRF ^] .800, Shimadzu, Japan), and the contents of amorphous silicon, aluminum, and sodium were calculated.

Caustic soda (NaOH, Sodium hydroxide, Wako pure chemical, purity 9 ~ .0wt% or more), water glass (N¾Si0 ₃ '¾0, Kanto chemical, Si0 ₂ 35 ~ 38wt%, Na _a 0

17 ~ 19wt¾), Sodium aluminate powder (NaAK, Junsei chemical, Na ₂ 0 35.0-39.0wt¾, 婦₃

52.0-56.0 t¾), Sodium aluminate solution (NaAi¾ n¾ (), ATEC Co., Ltd.), Na ₃ 0 20.0wt% _:

A1 ₂ 0 ₃ 19.0 wt%, ¾052 ¾) was used. In addition to sodium aluminate, metacarlin (Si0 ₂ 54.60wt, Al ₂ 0 ₃ 42,71ivi¾) calcined with a powder of chlorine for 2 hours at 700 t: was also used as a source of aluminum. 24 hours after mixing with water glass and sodium aluminate solution Of coking coal.

The compounding ratio is amorphous silicon and aluminium in the sample. The amount of sodium and the amount of silicon, aluminum and sodium in alkali activators and water and metacarlin. The Si / Al and Na / Ai burs of the geopolymer to be prepared were calculated by a computer program to which the present invention was applied (Table 3).

The weight ratio of the liquid phase (free water (molar added separately) in the alkali activator) to the weight of the sample was calculated, and the actual kneading of the blend was made using a mini slump cone made in the laboratory. It was measured by. Slum ^. The inner diameter of the bottom of the cone is 38. i 醒, the inner diameter of the top is 19 誦, and the cone height is 60.4 腦.

Geopolymer paste formulations are highly tacky, so they are thinner than cement, filled in mini slump cones, lifted off, separated, and then measured two diameters at the bottom of the floor after two minutes from the perpendicular to each other. Used. If the dough is significantly different, adjust the water content and mix again.

Mixing moles such as samples and alkali were mixed for 1 minute at a low speed and 1 minute at a high speed using a cement mixer, and then vibrated for 2 minutes on a vibrator that vibrated up and down to remove air trapped in the mixture. The compounding mall was poured into a cylindrical mold having a diameter of 29 腿 and a height of 60 删, closed with a seal, sealed for 72 hours with 70 R of silver in an uncontrolled humidity oven, taken out of Xingeun, and demolded from the mold after one day. -120 hours after the start of curing, the compressive strengths of the four specimens were measured according to the iiS F 2405 standard and the average compressive strength and standard deviation were calculated. In order to measure the compressive strength, the upper and lower surfaces of the cylindrical test specimens were polished with sandpaper such that the upper and lower surfaces were perpendicular to the sides and parallel to each other, and the height was 58 腿. The microstructure of the geopolymer fracture surface was observed with a scanning electron microscope (JEOL JSM-6380, Japan). Geopolymers were formulated between November 27 and December 1, 2012, and were exposed to air buildup from 4 days after blending to see if whitening was present.

2. Experimental Results and Discussion

Industrial analysis showed that the unburned carbon content of the sample was 13.94%. No carbon was detected in samples from unburned carbon by flotation. Hereinafter, "buried coal ash" or "sample" means a state in which carbon is removed. The chemical composition of the sample (coated coal ash) is shown in the table of FIG. The sum of si¾ and A1 ₂ 0 ₃ content exceeds 70% and the CaO content is less than 20%, and the chemical composition corresponds to Class F fly ash classified in ASTM C618 standard.

As a result of quantitative X-ray diffraction analysis, the crystalline content contained in the sample was the highest in mullite (22.6%) and quartz and maghemite in 8.5w «and 5.6%, respectively (graph 5).

6 is an amorphous component analysis result of the landfill coal material of Seocheon thermal power plant calculated from X-ray fluorescence spectroscopy and quantitative X-ray diffraction analysis. The content of amorphous silica was 36.8wt% and the content of amorphous alumina was 12.8 ¾, so the amorphous Si / Al ratio was 2.44. It was decided. Therefore, to prepare a geopolymer having a Si / Al ratio of less than 2.44, a solid sodium aluminate or sodium aluminate solution or metakaolin to supply aluminum was added, and water glass and NaOH were used when the Si / Al ratio was 2.5 and 3.0 ( See table in FIG. 3).

The compressive strength of the geopolymer made under the conditions shown in the table of FIG. 3 is shown in the graph of FIG. Compressive strength is the average of four specimens and the standard deviations are indicated. When the Si / Al ratio of the geopolymers were mixed with 2.0 and Na / Al ratios of 0.8 (sample 20AS, 20NaAl, 20MK) using different raw material combinations, the bottom diameter of the slumped compound after the mini slump test was similar in all three samples. In the case of 20AS sample, it was measured in the range of 40 ~ 40 讓.

The average compressive strength was 11.2 MPa (standard deviation 0.9 MPa) for 20AS sample using sodium aluminate solution and NaOH, and 12.3 MPa (standard deviation l. OMPa) for 20NaAl sample using solid sodium aluminate and NaOH. Indicated. Considering the standard deviation, there is no significant difference between the use of sodium aluminate as a solid and the solution. Therefore, it would be advantageous to use different solid aluminates rather than solutions that are difficult to store and transport. In addition, it will be easier to commercialize in that geopolymer is made by pouring only water such as forland cement using solid aluminate.

On the other hand, the average compressive strength of the 20MK sample using metakaolin instead of sodium aluminate as a source of aluminum was 9.1 MPa (standard deviation 2.0 MPa). The mechanical properties were slightly lower than those used. In the X-ray diffraction analysis, metakaolin is amorphous, but the short-range order is still maintained to some extent, which may be because the amount of semi-aluminum silica and alumina actually involved in the reaction was less than expected. It may be because aluminum is supplemented with meta-caline rather than sodium aluminate, so that the amount of alkali is relatively low. The water content was 23 wt% when the liquid alumina soda was used, but similar flowability was obtained when the water content was slightly increased to 24% when the solid aluminate was used (see the table in FIG. 3).

The addition of metakaolin should have increased the water content to 25%, due to the large specific surface area of the metakaolin particles and the plate-like particle shape, the water ratio required for the formulation should be high, and in fact the amount of free water was highest ( Table 3) may be the reason why the strength of the 20MK sample is somewhat lower among the three samples.

These three cases show that various raw materials can be blended to satisfy the chemical composition of the desired geopolymer, and the flow must be controlled according to the type of alkali, viscosity and additives used. In case of 20MK sample using metakaolin, the water content was the highest as 25wt%, but the L / S ratio was the smallest. Nevertheless, the mini slump test showed similar dough kneading. The three samples showed similar microstructures at the fracture surface observed with the scanning electron microscope (see FIG. 8). The microstructure shown in FIG. 8 has a slightly loose structure and large pores are observed and connected to each other. Differences in microstructure due to differences in compressive strength Duxson et al. Have shown that geopolymer microstructures are more closely related to Young's modulus than compressive strength. Since the Young's modulus of the geopolymer was not measured in this experiment, the relationship between the microstructure and the Young's modulus was not known.In this experimental condition, when the coal ash was activated with sodium aluminate and NaOH, even though the compressive strength increased, It did not make a difference.

Sample 25SS made of geopolymer with Si / Al = 2.5 using water glass and NaOH spread out to 40 ~ 43 腿 in mini-sulfum test and showed a similar dough kneader as the previous three cases with Si / Al = 2.0. The average compressive strength was 3.53MPa (standard deviation 0.8MPa). The 30SS-23 geopolymer sample with a Si / Al ratio of 3.0 showed an average compressive strength of 10.3 MPa (2.5 MPa for spring deviation), which was higher than 25 SS and similar to 20AS, despite the thin dough.

The 30SS-21 sample, which had the same Si / Al and Na / Al ratios but reduced the water content by 2wt¾, was spread to 39 ~ 45ι 腿 in the mini-sulfum test, showing a dough similar to the 25SS sample. The average compressive strength of the 30SS-21 sample was 17.9MPa (standard deviation 1.2MPa), which was nearly 5 times higher than 3.5MPa of the 25SS sample. Factors affecting the compressive strength of geopolymers are Si / Al and Na / Al ratios, the type and content of alkali metal ions, the size and distribution of unreacted Al-Si particles, and the surface reaction with geopolymer gels, water Content is known. It is difficult to say that the strength is high at some Si / Al ratio, because various factors affect it, but in the case of geopolymers made of metacarlin, Si /Al=1.8~2.5 Na / Al = 0.9 ~ 1.3 Is the maximum compressive strength when Lost

Geopolymers prepared from metakaolins of simple chemical compositions, such as silica and alumina, have been well studied in terms of the strength characteristics of geopolymers according to Si / Al and Na / Al ratios, while chemical composition, mineral content, particle size and shape It is difficult to generalize in various types of heterogeneous coal ash.

In this experiment, the Si / Al ratio of 2.0 geopolymer showed 9 ~ llMPa compressive strength, while 2.5 geopolymer showed 3.5MPa and 3.0 geopolymer showed 17.9MPa. It got worse and got better. These results need to be examined in terms of the components and characteristics of geopolymer components and alkali activators used in reaction. Since the reactive Si / Al ratio of the coal ash used as the raw material of the geopolymer is 2.44, two kinds of alkalis (sodium aluminate and NaOH) were added to supply aluminum from the alkali to make the geopolymer 2.0. In the case of 2.5, water glass and NaOH were added, and in the case of 3.0, two kinds of alkalis including water glass and NaOH which could supply silicon were added (see table in FIG. 3).

First, the 25SS sample was able to produce a geopolymer with a Si / Al ratio of 2.5 with a small amount of alkali. That is, since the amount of aluminum supplied from the alkali ¾-forming agent was small (1.9 wt% of water glass, 5.0 wt% of NaOH, see FIG. 3), semi-aluminum of coal ash was melted to participate in the geopolymer reaction.

How much aluminum can participate in geopolymer reactions is known to play a crucial role in the formation of geopolymer gels. Aluminum from thermal power plant fly ash The rate of melting in this alkali is also slower than in metakaolin, depending on the type and concentration of alkali. The 25SS sample was found to be low in alkali and did not dissolve a sufficient amount of aluminum from the coal ash. Therefore, the Si / Al ratio of geopolymer should be lower or higher than the reactive Si / Al ratio of coal ash.

On the other hand, the compressive strength of the geopolymer with Si / Al = 3.0 was predicted to increase as the water content decreased (see Fig. 7), which is consistent with the results of previous studies.

As a result of observing the fracture surface of the geopolymer gel with a scanning electron microscope, three samples having a Si / Al = 2.5 (FIG. 9 (a)) and three samples having a Si / Al = 3.0 (FIG. 9 (b) ~ ( In d)) an interesting difference was found. The surface shape of the 25SS sample (FIG. 9 (a)) exhibiting compressive strength of 3.5 MPa was Si / Al = 2.0 and the surface geometry of 20AS, 20NaAl, 20MK sample (Fig. 4) exhibiting compressive strength of 9-12 MPa. Very similar. On the other hand, in Fig. 9 (b), (c), (d) was observed particles that do not react with alkali, the geopolymer gel portion of the fine geopolymer gel compared to the sample of Si / Al = 2.0 and 2.5 It seemed to be well connected to each other.

In addition, the three samples showed no significant difference in the degree of adhesion between the crystalline particles and alkali polymers, which were not reacted with alkali. High compressive strength geopolymers have low porosity and are compact, exhibiting fine microstructure. The amount of silica solution added to the 30SS-23, 30SS-21, and 30SS-19 samples was 15.7-16.5 ¾, but there was no significant difference, but 1.9 ¾ of the 25SS sample was much higher (Table 3). In other words, when the silica content in the alkaline solution is high, the fine microstructure appears to develop, which is consistent with the existing research results. The chemical composition and flow control of geopolymers is a very important technique for the commercialization of geopolymers. It is possible to know the quantitative chemical composition of coal ash and calculate the compounding ratio to achieve the chemical composition of the target geopolymer as in this experiment. This is because the use varies depending on the chemical composition, and the difference in water content in the mixing of the geopolymer shows a large flow difference. For example, the dough kneading of the blends varied greatly with the same Si / Al ratio but with a 2 wt% difference in water content.

In addition, all geopolymers produced in this study did not show bleaching until now after exposure to air, because they can control the quantitative chemical composition of geopolymer systems.

3. Conclusion

Quantitative analysis of the landfill coal material at Seocheon Thermal Power Plant was used to calculate the amounts of semiungsung silicon and aluminum. From this, geopolymers with Si / Al ratios of 2.0, 2.5 and 3.0 were prepared from various raw materials.

By quantitatively evaluating the coal ash, it was possible to produce geopolymers having various Si / Al ratios at various blending ratios.

The Si / Al ratio of the geopolymer was better than the reactive Si / Al ratio of the coal ash, which resulted in better compressive strength.

Whitening could be prevented by using an appropriate amount of alkali activator, free from inefficient, inexpensive empirical formulations using excess alkali. In addition, the results showed that the microstructural properties of geopolymers differed when sodium aluminate and water glass were used as activators. The higher the silica content in the alkaline solution, the finer the microstructure of the geopolymer gel was formed. In the samples showing high compressive strength, the pore size was small and the fine microstructure showed better connectivity. As described above, the geopolymer formulation design method according to the present invention is a Si / Al ratio, Na / Al ratio of factors that have a significant effect on the physical properties of the geopolymer in the state of pre-set, the set value of these factors It provides a method to calculate the blending quantity of the satisfying geopolymer raw materials.

This provides a more scientific and systematic approach to geopolymer formulations, and provides an active research base for geopolymer structures and properties using specimens prepared from formulation designs according to the major factors of geopolymers. In addition, through the scientific compounding design according to the present invention can improve the economics of the use of raw materials, it is possible to adjust the factors that may cause problems such as the stability of the whitening of the produced geopolymer.

The present invention is expected to contribute to the revival of the geopolymer industry by providing the most important and fundamental data on the properties of geopolymers.

Although the present invention has been described with reference to an embodiment shown in the accompanying drawings, this is merely exemplary, and will be understood by those skilled in the art. It will be appreciated that various modifications and other equivalent embodiments are possible. Accordingly, the true scope of protection of the invention should be defined only by the appended claims.

Claims

[Range of request]

[Claim 1]

To determine the blending ratio of the base material containing the altuminosilicate component, and the geopolymer produced by mixing an alkali activator and water,

Raw material analysis step of analyzing the chemical composition by selecting the base material and alkali activator;

A basic calculation step of calculating the number of moles ( _mole ) of Si, Al, Na and H per unit weight of the basic raw material, alkali activator and water;

A target setting step of setting reference values for the main factors for determining the properties of the geopolymer, including the Si / Al mole ratio and Na / Al molar ratio in the finally prepared geopolymer; And

On the basis of the result calculated in the basic calculation step, the basic raw material, alkali activator and so as to satisfy the reference value of the main factor set in the target setting step in the mixture of the basic raw material, alkali activator and water Geopolymer blending design method comprising a; formulated ratio calculation step of calculating the respective blending ratio for water.

[Claim 2]

The method of claim 1,

In the target setting step, the main factor for determining the characteristics of the geopolymer, geopolymer blend design method characterized in that it further comprises a water content ratio.

[Claim 3]

The method of claim 1,

And wherein said raw material analysis step performs pre-treatment to remove unburned carbon powder from said basic raw material.

[Claim 4]

The method of claim 1,

In the basic calculation step, except for the crystalline portion of the base material, the geopolymer, characterized in that for each of the mole (Sile) for Si, Al, Na and H only for the portion present in the amorphous Formulation method.

[Claim 5]

The method of claim 1,

In order to calculate the content of Si, Al, Na, H in the basic calculation step, by measuring the content of the specific components of Al ₂ ¾, Si0 ₂ , Na ₂ 0, ¾0 contained in the basic raw materials, additives and water, respectively Then, geopolymer blend design method characterized in that for calculating the number of moles of each of the Si, Al, Na, H contained in the detail components.

[Claim 6]

In U,

In the calculation step, geopolymer blend design method characterized in that the analysis of the Si / Al molar ratio and Na / Al molar ratio of the base material.

[Claim 7]

The method of claim 6,

In the target setting step, geopolymer formulation design method characterized in that the reference value of the Si / Al molar ratio is set higher or lower than the Si / Al molar ratio of the base material.

[Claim 8]

The method of claim 1,

In selecting the sodium aluminate as the alkali activator in the raw material analysis step, geopolymer formulation design method characterized in that for selecting a solid state sodium aluminate powder.

[Claim 9]

As to determine the blending ratio of the base material containing the aluminosilicate component, and the geopolymer produced by mixing the alkali activator, additives and water,

A target setting step of setting and inputting reference values for the main factors for determining the properties of the geopolymer, including the Si / Al mole ratio, Na / Al mole ratio, and water weight ratio in the finally prepared geopolymer;

A basic calculation step of calculating a total of 16 data on the number of moles of Si, Al, Na, and H per unit weight of the basic raw material, alkali activator, additive, and water; And

On the basis of the results calculated in the basic calculation step, in the mixture of the base material, alkali activator, additives and water of the main factor set in the target setting step Geopolymer blending design method comprising a; formulated ratio calculation step of calculating the respective blending ratio for the base material, alkali activator, additives and water so as to satisfy the reference value.

[Claim 10] The method of claim 9,

The basic calculation step, in order to calculate the content of Si, Al, Na, H in the basic calculation step, A1 ₂ 0 ₃ , Si0 ₂ , Na ₂ 0, H contained in the basic raw materials, additives and water, respectively Entering 16 data on the subcomponent content of ₂ 0, the number of moles of Si, Αί, Na, H contained in the subcomponents is calculated by mathematical method. .

Claim 11 A recording medium containing a computer program for determining a blending ratio of a basic raw material containing an aluminosilicate component and a geoplymer prepared by mixing an alkali activator, an additive, and water, according to claim 9 or 10. The geopolymer blending design method described in the document is described in the form of a program that can be executed on a computer.