Method for producing activated fillers

Abstract

The aim is to minimize variations in the quality of fly ash used as an active filler, regardless of whether it is supplied by a supplier or used by a customer. [Solution] The method for producing an activated filler is a method for producing an activated filler that will be used as a material for a hardened body, and includes an activation step (S1) in which mechanical energy is applied using a ball mill to a starting material consisting of raw powder which is fly ash before classification, type II ash which is fly ash classified to JIS type II, or JIS outer ash which is fly ash which does not conform to JIS A 6201, so that the surface of the individual particles constituting the starting material becomes amorphous.

Description

Technical Field

[0001] The present invention relates to a method for producing an active filler.

Background Art

[0002] Conventionally, various techniques for producing a cured body containing fly ash as one of the materials and the materials thereof have been proposed. For example, in Patent Document 1, a first step of subjecting fly ash to a mechanochemical treatment to activate the surface, a second step of mixing a strong alkali solution and silicon fine powder to prepare a silicon mixture in which a silicon component is eluted in the strong alkali solution, and a third step of mixing the fly ash with the surface activated and the silicon mixture are described for a method for producing a self-hardening material.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Fly ash is known to have quality variations depending on the type of coal as a raw material, the characteristics of power plant boilers, combustion conditions, etc. This has long been said to be one of the factors hindering the nationwide spread of fly ash. When such fly ash with quality variations is used as an active filler in the production of a cured body such as geopolymers, etc., the quality of the cured body (strength, time required to reach a predetermined strength, etc.) may also vary. On the other hand, there are also regions where efforts are being made to enhance the reactivity of the supplied fly ash by collecting fly ash (specific surface area with a fineness close to Class I in JIS A 6201) that has been sorted to only fine powder by a classification device. However, such efforts are also in a situation where it is difficult to be widely implemented nationwide, similar to the supply situation of Class I fly ash.

[0005] One aspect of the present invention has been made in view of the above-mentioned problems, and its purpose is to reduce variations in the quality of fly ash used as an active filler, not limited to the supplier and the end customer. [Means for solving the problem]

[0006] To solve the above problems, a method for producing an activated filler according to one aspect of the present invention is a method for producing an activated filler that will be used as a material for a hardened body, and includes an activation step in which mechanical energy is applied using a ball mill to a starting material consisting of raw fly ash before classification, Class II ash which is fly ash classified to JIS Class II, or JIS outer ash which is fly ash that does not conform to JIS A 6201, so that the surface of the individual particles constituting the starting material becomes amorphous. [Effects of the Invention]

[0007] According to one aspect of the present invention, variations in the quality of fly ash used as an active filler can be reduced, regardless of whether it is supplied by a supplier or used by a customer. [Brief explanation of the drawing]

[0008] [Figure 1] This flowchart shows the process for producing the active filler according to the present invention. [Figure 2] This is a magnified photograph showing the starting material particles and the active filler particles produced by the method for producing the active filler according to the embodiment. [Figure 3] This figure shows the powder X-ray diffraction patterns of the starting material particles and the active filler particles produced by the method for producing the active filler according to the embodiment. [Figure 4] This graph shows the amount of metal ions eluted from each starting material, the amount of metal ions eluted from the active filler in the example, and the amount of metal ions eluted from the active filler in the comparative example. [Figure 5]This graph shows the relative ratio of metal ion content and the relative ratio of metal ion elution amounts in Type II ash from different origins. [Figure 6] This graph shows the relationship between the median diameter of the active filler powder and the amount of metal ions eluted in the example. [Modes for carrying out the invention]

[0009] <Embodiment> Embodiments of the present invention will be described in detail below.

[0010] [Flowchart for manufacturing activated filler] First, the method for manufacturing the activated filler according to this embodiment will be described. Figure 1 is a flowchart showing the flow of the method for manufacturing the activated filler according to this embodiment. The activated filler is a powder that is one of the materials for the cured body. The cured body includes geopolymers, concrete, etc. The method for manufacturing the activated filler includes an activation step S1. The method for manufacturing the activated filler according to this embodiment further includes a preparation step S2.

[0011] (Preparation process S2) In the method for producing the activated filler according to this embodiment, a preparation step S2 is performed before proceeding to the activation step S1. In the preparation step S2, the starting material is prepared. The "starting material" consists of fly ash. Specifically, it consists of raw powder, Class II ash, or JIS external ash. Raw powder refers to fly ash before classification. Class II ash refers to fly ash that has been classified to conform to Class II of JIS A 6201. JIS external ash is fly ash that has been classified from the raw powder but did not conform to JIS A 6201. The "preparation" of the starting material includes selecting the fly ash to be used as the starting material from among the various types of fly ash, and putting the starting material into the rotating container of the ball mill. When Class II ash or JIS external ash is used as the starting material, the preparation may also include classifying the raw powder to obtain Class II ash or JIS external ash.

[0012] Furthermore, the preparation also includes measuring the median diameter of the fly ash, which is a candidate for the starting material, to determine its suitability as a starting material. Raw flour that has not undergone the classification process contains Grade I ash, but the content is generally not constant. Therefore, when preparing raw flour as a starting material, the suitability as a starting material can be determined by measuring the d50μm of the raw flour and confirming that it is not below 10μm, which is the particle size corresponding to Grade II ash. This can also be used to determine the suitability of raw flour when using JIS non-conforming ash or raw flour mixed with JIS non-conforming ash that does not conform to JIS A 6201 as a starting material. It should be noted that the determination of the suitability of starting materials using median diameter as a judgment indicator is not limited to fly ash raw flour or JIS non-conforming ash, and does not preclude its application to JIS-compliant fly ash (Grade II ash, etc.) or clinker ash.

[0013] In the activation step S1 described later, a planetary ball mill is used as the ball mill. Therefore, in the preparation step S2 according to this embodiment, the planetary ball mill is also prepared. Furthermore, it is desirable to use a dry ball mill from the viewpoint of preventing the impact applied to the starting material from being mitigated. The "preparation" of the ball mill includes putting balls into the rotating container of the ball mill. It is desirable to use balls with a diameter in the range of 0.5 cm to 1.5 cm as the balls to be put into the rotating container of the planetary ball mill together with the starting material. Furthermore, it is desirable to use balls made of a metal with excellent wear resistance, and it is especially desirable to use balls made of zirconia, stainless steel, bearing steel, etc.

[0014] (Activation step S1) After preparing the starting materials and the like, proceed to the activation step S1. In the activation step S1, using a ball mill, mechanical energy is applied to the starting materials so that the surfaces of the individual particles constituting the starting materials become amorphous. "Applying mechanical energy" refers to causing the balls to collide with the starting materials by rotating the rotating container of the ball mill. "The surface of the particles becomes amorphous" means that, unlike simply pulverizing the particles, when mechanical energy is applied to the solid particles, strain occurs in the crystal lattice of the solid, and an active surface is formed by becoming amorphous. For example, as shown in FIG. 2, it means that unevenness is formed on the surface while maintaining the rough prototype of the original particles. More specifically, when evaluating the crystallinity using the powder X-ray diffraction method, as shown in FIG. 3 for example, compared to the X-ray diffraction pattern of the original particles, it approaches a halo pattern, specifically, the structure becomes such that the height of the peak decreases. In the activation step S1 according to the present embodiment, the rotating container of the planetary ball mill into which the above balls are charged is rotated for 60 minutes or more and less than 180 minutes to continuously apply mechanical energy to the starting materials. At that time, it is desirable to rotate the rotating container at a rotational speed of 600 rpm.

[0015] (Modified Example) In the above embodiment, the case of using a small planetary ball mill used in experiments and the like was described as an example. However, it is also possible to obtain the same results in an industrial large-scale planetary ball mill. Specifically, a simulation of the ball behavior in an industrial large-scale planetary ball mill is performed in advance, and grinding conditions are calculated such that the ratio of the vertical component to the tangential component of the collision energy is equal to that when using a small planetary ball mill. Then, the large-scale planetary ball mill is operated under the calculated grinding conditions. Details of this method are disclosed, for example, in Yoshiyuki Mizuno et al., "About the scale-up method of a high-speed planetary mill in the mechanochemical field", Kurimoto Technical Report No. 51, etc.

[0016] In addition, in the above-described embodiment, the case of using a planetary ball mill has been exemplified, but the device to be used is not limited to a planetary ball mill. Any device may be used as long as it can amorphize the surface of each particle constituting the starting material. Such devices include general ball mills, tube mills, and the like.

[0017] 〔Function and effect of the method for producing an active filler〕 In the method for producing an active filler described above, in the activation step S1, mechanical energy is applied to a starting material composed of raw powder, type II ash, off-JIS ash, or fly ash having a median diameter of 10 μm or more using a ball mill so that the surface of each particle constituting the starting material is amorphized. The thus-produced active filler in which each particle is amorphized elutes more metal ions when mixed with other materials, for example, for the production of a cured product such as geopolymers, than the active filler before the application of mechanical energy. This indicates that the reactivity between the active filler and other materials increases, and the strength of the cured product increases. Also, the degree of increase in the elution amount of metal ions due to the application of mechanical energy is larger than that of an active filler produced by applying the same mechanical energy to type I ash. That is, by using the above method for producing an active filler, the quality of a low-grade starting material (raw powder, type II ash, off-JIS ash, or fly ash having a median diameter of 10 μm or more) can be made closer to the quality of type I ash. Further, even if there is a difference in the metal ion elution amount of the raw powder or type II ash before the application of mechanical energy depending on the production area (the thermal power plant where it is discharged), this difference is reduced by applying mechanical energy. Therefore, according to the method for producing an active filler, it is possible to reduce the variation in quality not only for the suppliers and demanders of fly ash used as an active filler but also for any fly ash. As a result, for example, at a site where type I ash has conventionally been used as an active filler, a low-grade active filler can also be used.

Example

[0018] An example of the present invention will be described below.

[0019] First, in preparation step S2, a 1.0 cm diameter ball made of zirconia was prepared and placed in the rotating container of the planetary ball mill. Also in preparation step S2, the raw powder and type II ash were prepared. For comparison, type I ash was also prepared.

[0020] Next, in the activation step S1, the rotation speed of the planetary ball mill's rotating vessel was set to 600 rpm, and mechanical energy was continuously applied to the raw powder for 60 minutes to produce the activated filler according to Example 1-1. Similarly, the rotation speed of the rotating vessel was set to 600 rpm, and mechanical energy was continuously applied to the raw powder for 180 minutes to produce the activated filler according to Example 1-2. Likewise, the rotation speed of the rotating vessel was set to 600 rpm, and mechanical energy was continuously applied to type II ash for 60 minutes and 180 minutes to produce the activated fillers according to Examples 2-1 and 2-2, respectively. Likewise, the rotation speed of the rotating vessel was set to 600 rpm, and mechanical energy was continuously applied to type I ash for 60 minutes and 180 minutes to produce the activated fillers according to Comparative Examples 1-1 and 1-2, respectively.

[0021] Next, the metal ions (Al) of each starting material (raw powder, type II ash, type I ash) before mechanical energy is applied. 3+ Si 4+ The amount of each eluted was measured. Specifically, at room temperature, first, an amount of the active filler according to Example 1-1 was added to a predetermined amount of 30 wt% NaOH solution such that the solid-liquid ratio (active filler:NaOH solution) was 0.1 g:10 ml. The mixture of active filler and NaOH was then shaken at a speed of 300 r / min for 24 hours. The amount of Al eluted into the mixture was then measured. 3+ Si 4+ The total elution amount (mg / L) of each active filler (Examples 1-2, 2-1, 2-2, Comparative Examples 1-1, 1-2) was measured using the same method as for the active filler in Example 1-1. 3+ Si 4+ The total elution amount for each was also measured. Figure 4 is a graph showing the measurement results.

[0022] As shown in Figure 4, the total amount of metal ions eluted from type I ash before mechanical energy was applied was 137.4 mg / L. Furthermore, the total amount of metal ions eluted from the activated filler in Comparative Example 1-1, which was prepared by continuously applying mechanical energy to type I ash for 60 minutes, was 203.9 mg / L, which was 1.48 times that of type I ash. Furthermore, the total amount of metal ions eluted from the activated filler in Comparative Example 1-2, which was prepared by continuously applying mechanical energy to type I ash for 180 minutes, was 235.5 mg / L, which was 1.71 times that of type I ash.

[0023] In contrast, the total amount of metal ions eluted from the raw powder before mechanical energy was applied was 111.8 mg / L. Furthermore, the total amount of metal ions eluted from the activated filler in Example 1-1, which was prepared by continuously applying mechanical energy to the raw powder for 60 minutes, was 398.6 mg / L, which was 3.57 times that of the raw powder. Furthermore, the total amount of metal ions eluted from the activated filler in Example 1-2, which was prepared by continuously applying mechanical energy to the raw powder for 180 minutes, was 508.8 mg / L, which was 4.55 times that of the raw powder.

[0024] Furthermore, the total amount of metal ions eluted from the raw powder before the application of mechanical energy was 0.81 times that of type I ash, whereas the total amount of metal ions eluted from the activated filler in Example 1-1 was 1.95 times that of Comparative Example 1-1. Similarly, the total amount of metal ions eluted from the activated filler in Example 1-2 was 2.16 times that of Comparative Example 1-2. In other words, the activated fillers in Examples 1-1 and 1-2 both showed improved metal ion elution compared to type I ash and Comparative Examples 1-1 and 1-2. This indicates that the activated fillers in Examples 1-1 and 1-2 are of a quality that allows them to be used as a substitute for type I ash.

[0025] Furthermore, the total amount of metal ions eluted from the Type II ash before the application of mechanical energy was 20.97 mg / L. In addition, the total amount of metal ions eluted from the activated filler in Example 2-1, which was prepared by continuously applying mechanical energy to the Type II ash for 60 minutes, was 315.2 mg / L, which was 15.1 times that of the Type II ash. In addition, the total amount of metal ions eluted from the activated filler in Example 2-2, which was prepared by continuously applying mechanical energy to the Type II ash for 180 minutes, was 562 mg / L, which was 26.8 times that of the Type II ash.

[0026] Furthermore, while the total amount of metal ions eluted from Type II ash before the application of mechanical energy was 0.15 times that of Type I ash, the total amount of metal ions eluted from the activated filler in Example 2-1 was 1.54 times that of Comparative Example 1-1. Similarly, the total amount of metal ions eluted from the activated filler in Example 2-2 was 2.39 times that of Comparative Example 1-2. In other words, the activated fillers in Examples 2-1 and 2-2, like those in Examples 1-1 and 1-2, all showed improved metal ion elution compared to Type I ash and Comparative Examples 1-1 and 1-2. This indicates that the activated fillers in Examples 2-1 and 2-2 are of a quality that allows them to be used as a substitute for Type I ash.

[0027] Furthermore, two types of Type II ash from different origins (Maizuru and Takehara) were prepared, and mechanical energy was continuously applied to each type of Type II ash for 60 minutes to produce two types of activated filler (60 min). Additionally, mechanical energy was continuously applied to each type of Type II ash for 180 minutes to produce two types of activated filler (180 min). The metal ion content of the Maizuru-produced Type II ash and the Takehara-produced Type II ash was then measured. The total amount of metal ions eluted from the Maizuru-produced Type II ash, the Takehara-produced Type II ash, the Maizuru-produced activated filler (60 min), the Takehara-produced activated filler (60 min), the Maizuru-produced activated filler (180 min), and the Takehara-produced activated filler (180 min) was measured using the same method as described above. Then, the ratio of the total amount of Type II ash leached from Maizuru to the total amount of Type II ash leached from Takehara, the ratio of the total amount of activated filler leached from Maizuru (60 min) to the total amount of activated filler leached from Takehara (60 min), and the ratio of the total amount of activated filler leached from Maizuru (180 min) to the total amount of activated filler leached from Takehara (180 min) were calculated. Figure 5 is a graph showing the calculation results.

[0028] As shown in Figure 5, the ratio of the total elution amount of Type II ash from Maizuru to the total elution amount of Type II ash from Takehara was 0.90, while the ratio of the total elution amount of activated filler from Maizuru (60 min) to the total elution amount of activated filler from Takehara (60 min) was 0.98. Furthermore, the ratio of the total elution amount of activated filler from Maizuru (180 min) to the total elution amount of activated filler from Takehara (180 min) was 1.01. In other words, by applying mechanical energy, the variation in quality between different production areas of Type II ash is reduced. This indicates that when using Type II ash, there is no need to worry about the production area.

[0029] Figure 6 is a graph showing the relationship between the median diameter (μm) and the total amount of metal ions eluted from various fly ash samples before the activation step S1. Here, the median diameter refers to the particle size at which the cumulative distribution function of the particle size distribution is 0.5, and is commonly referred to as d50. The activated filler from Maizuru (60 min) is the activated filler for Example 2-1, the activated filler from Maizuru (180 min) is the activated filler for Example 2-2, the activated filler from Takehara (60 min) is the activated filler for Example 3-1, and the activated filler from Takehara (180 min) is the activated filler for Example 3-2. Examples 1-1, 1-2, Comparative Example 1-1, and Comparative Example 1-2 are as described above.

[0030] The d50 of Grade I fly ash, which is fly ash classified to conform to JIS A 6201 Grade I, was 5.3 μm. Similarly, the d50 of Grade II fly ash, which conforms to JIS A 6201 Grade II, was 12.5 μm for Maizuru and 1.5 μm for Takehara. The d50 of the raw flour was 18.9 μm. The raw flour contains Grade I fly ash before classification.

[0031] Although the total amount of metal ions leached from fly ash that did not undergo the activation process S1 was highest for Type I ash, the amount of metal ions leached from Type II ash (Examples 2-1, 2-2, 3-1, 3-2) and raw powder (Examples 1-1, 1-2) that underwent the activation process S1 significantly exceeded that of Type I ash and Type I ash that underwent the activation process S1 (Comparative Example 1-1, Comparative Example 1-2). This indicates that even fly ash that has not been classified and classified according to JIS standards can be judged to be suitable as a starting material if its d50 is 10 μm or more (it can be used as a target for applying mechanical energy in this invention).

[0032] 〔summary〕 A method for producing an activated filler according to Embodiment 1 of the present invention is a method for producing an activated filler that will be used as a material for a hardened body, and includes an activation step in which mechanical energy is applied using a ball mill to a starting material consisting of raw powder which is fly ash before classification, Class II ash which is fly ash classified to JIS Class II, or JIS outer ash which is fly ash which does not conform to JIS A 6201, so that the surface of the individual particles constituting the starting material becomes amorphous.

[0033] The method for producing the active filler according to aspect 2 of the present invention may also be a method in which fly ash having a median diameter of 10 μm or more is used as the starting material in aspect 1 described above.

[0034] The method for producing the activated filler according to aspect 3 of the present invention may also be a method in which fly ash with a median diameter of 10 μm or more of the JIS outer ash is used as the starting material in aspect 1 or 2 described above.

[0035] A method for producing an active filler according to aspect 4 of the present invention may also be a method in which, in any one of aspects 1 to 3 above, fly ash with a median diameter of 10 μm or more in a mixture of the raw powder and the JIS outer ash is used as the starting material.

[0036] A method for producing an active filler according to aspect 5 of the present invention may also be a method in which, in any one of aspects 2 to 4 described above, the median diameter of the fly ash is measured and it is determined whether the fly ash is suitable as a starting material with a median diameter of 10 μm or more. A method for producing an active filler according to claims 2 to 4.

[0037] The method for producing an active filler according to aspect 6 of the present invention may also be a method in which a planetary ball mill is used as the ball mill in any one of the above aspects 1 to 5.

[0038] A method for producing an active filler according to aspect 7 of the present invention may also be a method in which, in any one of aspects 1 to 6 above, the rotating vessel of the ball mill is rotated for 30 minutes or more but less than 180 minutes to continuously apply mechanical energy to the starting material.

[0039] A method for producing an active filler according to aspect 8 of the present invention may also be a method in which, in any one of aspects 1 to 7 above, the rotating vessel is rotated at a rotational speed of 600 rpm to apply mechanical energy to the starting material.

[0040] The method for producing an active filler according to aspect 9 of the present invention may also be a method in which, in any one of aspects 1 to 8 above, balls with a diameter in the range of 0.5 cm to 1.5 cm are used as balls to be put into the rotating container together with the starting material.

[0041] A method for producing an active filler according to aspect 10 of the present invention may also be a method in which, in any one of the above aspects 1 to 9, balls made of zirconia are used as balls to be introduced into the rotating container together with the starting materials. [Explanation of Symbols]

[0042] S1 activation process S2 preparation process

Claims

1. A method for producing an active filler that will be used as a material for a cured body, The process includes an activation step in which mechanical energy is applied using a ball mill to a starting material consisting of raw fly ash before classification, Class II fly ash classified to JIS Class II, or JIS outer ash which does not conform to JIS A 6201, so that the surface of the individual particles constituting the starting material becomes amorphous. A method for producing activated fillers.

2. The aforementioned raw material uses fly ash with a median diameter of 10 μm or more as the starting material. A method for producing the active filler according to claim 1.

3. The starting material is fly ash with a median diameter of 10 μm or more, as specified in the JIS standard. A method for producing the active filler according to claim 1.

4. The starting material is fly ash with a median diameter of 10 μm or more in a mixture consisting of the aforementioned raw powder and the aforementioned JIS outer ash. A method for producing the active filler according to claim 1.

5. The median diameter of the fly ash is measured, and it is determined whether the fly ash is suitable as a starting material with a median diameter of 10 μm or more. A method for producing an active filler according to any one of claims 2 to 4.

6. As the aforementioned ball mill, a planetary ball mill is used. A method for producing the active filler according to claim 1.

7. The rotating vessel of the ball mill is rotated for 60 minutes or more but less than 180 minutes, continuously applying mechanical energy to the starting material. A method for producing an active filler according to claim 1 or 2.

8. The rotating vessel is rotated at a rotational speed of 600 rpm to apply mechanical energy to the starting material. A method for producing the active filler according to claim 7.

9. The balls to be placed in the rotating container along with the starting materials are balls with a diameter in the range of 0.5 cm to 1.5 cm. A method for producing the active filler according to claim 8.

10. As the balls to be placed in the rotating container together with the starting material, balls made of zirconia are used. A method for producing the active filler according to claim 9.

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