JP6721209B2 - Dust generation suppression material and dust generation suppression method - Google Patents

Description

The present disclosure relates to a dust generation suppressing material and a dust generation suppressing method.

As a means to control the generation of dust in facilities equipped with surface soil (eg, stadiums for various sports, schoolyards, parks, etc.), inorganic salts having hygroscopicity and deliquescent such as calcium chloride and magnesium chloride are used as topsoil. The method of spraying has been taken (for example, refer to Patent Document 1).

Japanese Patent Publication No. 8-9847

However, since inorganic salts such as calcium chloride and magnesium chloride run away each time it rains or sprinkles, it is necessary to spray them repeatedly, and there is a problem that maintenance and management thereof require a great cost. In addition, the above-mentioned inorganic salts dissolved in water cause damage to vegetation and the like in the ground, and promote the oxidation (rust formation) of iron playground equipment, benches, goals, and fences installed in the ground. This has shortened the useful life of these appliances and equipment, which is also a problem from the viewpoint of safety management.

From the above-mentioned circumstances, it is desirable to provide a dusting suppressing material and a dusting suppressing method that can obtain an excellent dusting suppressing effect without compounding the above-mentioned inorganic salts.

The dust generation suppressing material of the present disclosure is laid on the existing surface soil in a facility equipped with the existing surface soil, or is mixed with the existing surface soil by stirring and mixing, so that the dust suppressing material emits more dust than the existing surface soil. A dust generation suppressing material capable of forming a new surface soil in which dust is suppressed, wherein at least one of high-quality soil and stone powder is used as a base material, and precipitable barium sulfate is mixed with the base material.

In the dust control material of the present disclosure, examples of facilities provided with existing surface soil include, for example, various clay-based grounds such as athletic fields, baseball fields, soccer fields, rugby fields, tennis courts, gateball fields, and other ball sports fields. , Multi-purpose stadiums, parks, other multi-purpose open spaces, school playgrounds (schools), kindergarten playgrounds, walking paths, etc. ) Can be mentioned.

Further, in the dust generation suppressing material of the present disclosure, the good quality soil is a soil having a quality that can be used as the surface soil in a facility including the existing surface soil without soil improvement. As good quality soil, it can be sufficiently compacted as surface soil in the above facilities, has physical properties that do not easily become mud after rainfall, and contains foreign substances such as wood chips, metal fragments, plastic fragments, concrete blocks, and asphalt blocks. Instead, a sandy soil, a gravel soil, or the like that has the maximum grain size (preferably 7 mm or less) and the design CBR (California Bearing Ratio) satisfying the required criteria is selected. Specific examples of such high-quality soil include, for example, Masa soil, mountain sand, red soil, black soil, Arakida soil, and Iwase sand.

Further, in the dust generation suppressing material of the present disclosure, the stone powder is a sieve having a mesh size of not more than a predetermined value (preferably not more than 3 mm) among crushed products obtained by crushing rocks or calcined soil (for example, brick>). It is an artificial soil that can pass through. Crushed rock is also called crushed stone screenings. Such stone powder is used in ground pavements and the like. Depending on the characteristics of the host rock and the difference in the pulverizer, there are some types of stone powder that have a particle size distribution of particles with a particle size of 0.1 mm or less, while those with a particle size of 0.1 mm or less do not. Since it causes mud formation, it is ideally suppressed to 20% or less. Specific examples of such stone powder include, for example, limestone screenings, green screenings, black screenings, antukers, and the like.

According to the dust suppressing material configured in this way, since each component as described above is blended, it should be laid on the existing surface soil or stirred and mixed with the existing surface soil. This makes it possible to construct a new surface soil in which dust generation is suppressed as compared with the existing surface soil. Such a dust generation suppressing effect is an effect that the inventors have found by repeating indoor experiments and outdoor experiments, and it is obvious that such an effect can be obtained by looking at matters exemplified in the embodiments described later. Become.

The reason why the desired dust generation suppressing effect is obtained by blending the above-mentioned respective components is speculative, but the following reasons are conceivable. First, since the above-mentioned dust generation inhibiting material contains precipitated barium sulfate, it is presumed that the precipitated barium sulfate fine particles adhere to the surface of the clay mineral particles which are the main cause of dust generation. As a result, it is considered that the individual clay mineral particles become heavy and the scattering of the clay mineral particles is suppressed.

In addition, it is important to use precipitated barium sulfate in the dust control material of the present disclosure. That is, even if barium sulfate is used, it is difficult to obtain a sufficient effect by using barbaric sulfate. This is because barium sulphate is a crushed product of a natural mineral called barite, so it has a larger particle size than precipitated barium sulphate synthesized by a chemical reaction, and precipitated barium sulphate is a particle. This may be because the adhesiveness to clay mineral particles is lower than that of precipitated barium sulfate due to the different shapes. That is, the dust generation suppressing material of the present disclosure does not simply add barium sulfate having a large specific gravity to increase the apparent specific gravity.

Furthermore, in the dust generation suppressing material of the present disclosure, it is important to mix the sedimentable barium sulfate in the base material containing at least one of the high-quality soil and the stone powder, instead of using the sedimentary barium sulfate alone. is there. If the precipitated barium sulfate is used alone, for example, the precipitated barium sulfate is sprayed on the existing surface soil, and if necessary, the dispersed precipitated barium sulfate and surface soil are stirred and mixed, It is also possible to apply the sedimentable barium sulfate to the existing surface soil by such a method. However, even if the sedimentary barium sulfate is applied to the existing surface soil by such a method, it is difficult to maintain the dust generation suppressing effect for a long time in a general clay ground or the like.

On the other hand, when the dust suppressing material of the present disclosure is configured by blending the sedimentary barium sulfate in the base material containing the good quality soil and stone powder, when the dust suppressing material is laid on the existing surface soil. As compared with the case where the precipitated barium sulfate is used alone, the dust generation suppressing effect can be maintained for a longer period of time. Alternatively, when the dust suppressing material of the present disclosure and the existing surface soil are stirred and mixed, the dust suppressing effect can be maintained for a longer period of time as compared with the case where the precipitated barium sulfate is used alone.

When the dust generation suppressing material is laid on the existing surface soil, it is preferable that the base material contains high-quality soil and stone powder. When mixing and mixing the dust suppression material and the existing surface soil, good quality soil and stone powder may be contained in the base material, but only one of the good soil and stone powder may be included depending on the composition of the surface soil. It may be contained in the base material. For example, when the surface soil component is a high quality soil or a component similar to the high quality soil, only the stone powder may be contained in the base material. When the surface soil component is stone powder or a component similar to stone powder, the base material may contain only good quality soil. In any of these cases, if the dust suppression material and the existing surface soil are agitated and mixed, the new surface soil after mixing will contain either of good quality soil and stone powder, or both. On the other hand, a component similar to the other is contained, and further, precipitated barium sulfate is contained.

It has been experimentally confirmed that the dust-preventing effect can be maintained for a longer period of time by such a prescription, and the reason therefor can only be speculated, but the following reasons are considered. When sedimentable barium sulfate is used alone, the specific gravity of the existing surface soil component (such as clay) and sedimentable barium sulfate are significantly different. Therefore, for example, when sports or the like is performed and the surface of the surface soil is roughened, or when mud occurs due to rainfall or the like, the sinking barium sulfate quickly sinks into the deep layer of the surface soil. As a result, the precipitated barium sulfate remaining near the surface of the surface soil is reduced at an early stage, and as a result, the clay mineral particles near the surface of the surface soil tend to be easily scattered as dust.

On the other hand, when the sedimentation barium sulfate is formed by mixing the sedimentary barium sulfate in the base material containing the high-quality soil and the stone powder, the stone powder and the sedimentable barium sulfate form a component that constitutes the existing surface soil (for example, The difference in specific gravity is smaller than the difference in specific gravity between clay and the like) and precipitated barium sulfate. Therefore, the presence of the stone powder slows down the sinking barium sulfate into the deep layer of the surface soil, and suppresses the decrease of the sinking barium sulfate remaining near the surface of the surface soil.

Further, the particles of stone powder have higher rigidity than the particles of the clay minerals that form the surface soil. Therefore, in the case of clay minerals, particles tend to collapse, and the precipitated barium sulphate adhering to the surface of such collapsed particles further falls into the surrounding minute gaps, and such a phenomenon is repeated. At this point, the sinking barium sulfate sinks deep into the surface soil. On the other hand, in the case of stone powder, the particles are unlikely to collapse, so that the precipitated barium sulfate adhering to the stone powder particles is likely to be maintained in the state of adhering to the stone powder. Moreover, since the stone powder particles themselves have a larger particle size than the sedimentable barium sulfate, they do not fall into the finer gaps than the sedimentable barium sulfate, and the tendency to sink to the deeper layer of the surface soil is not so strong as the sedimentable barium sulfate. Therefore, the stone powder easily remains on the upper portion of the surface soil, and the precipitated barium sulfate is likely to remain on the upper portion of the surface soil because the precipitated barium sulfate adheres to the surface of the remaining stone powder. Due to this, there is a possibility that the decrease of the sedimentary barium sulfate remaining near the surface of the surface soil may be suppressed.

Furthermore, the coexistence of such stone powder and sedimentable barium sulfate with the high-quality soil or a component similar to the high-quality soil also exerts an appropriate water-retaining power that cannot be obtained only with the stone powder and the sedimentable barium sulfate. Therefore, such moisture also contributes to the suppression of dust generation. The high-quality soil may contain particles of clay minerals that cause dust, but the particles of such clay minerals and particles of precipitated barium sulfate have different particle sizes. Therefore, particles of precipitated barium sulfate having a smaller particle size adhere to the surface of the clay mineral particles, which increases the apparent specific gravity of the clay mineral particles and makes it difficult for the clay mineral particles to scatter. Conceivable.

The dust generation suppressing material of the present disclosure may further include the following configurations.
First, in the dust generation suppressing material of the present disclosure, the base material contains high-quality soil, and the high-quality soil has a particle size that can pass through a sieve having an opening of 4 to 8 mm and a particle size of 0. A component of less than 1 mm may be suppressed to less than 20% in volume ratio with respect to the whole good quality soil. Regarding such a good quality soil, the maximum particle size of the particle size that can pass through a sieve having an opening of 4 to 8 mm is substantially synonymous with 4 to 8 mm. However, for example, particles having a major axis of more than 8 mm and a minor axis of less than 8 mm may pass through a sieve having an opening of 8 mm, and the dust generation suppressing material of the present disclosure contains some such good soil particles. Since it does not matter, the particle size is defined as a particle size that can pass through a sieve having an opening of 4 to 8 mm. In addition, in the dust generation suppressing material of the present disclosure, from the viewpoint of suppressing dust generation, it is preferable that the component having a particle diameter of less than 0.1 mm is suppressed to less than 20% by volume ratio with respect to the whole good soil.

Further, in the dust generation suppressing material according to the present disclosure, the base material contains stone powder, and the stone powder has a particle size that can pass through a sieve having an opening of 1 to 3 mm and a particle size of 0.1 mm. The content of less than 20% by volume may be suppressed to less than 20% by volume ratio with respect to the entire stone powder. The particle size that can pass through a sieve having an opening of 1 to 3 mm is substantially synonymous with the maximum particle size of 1 to 3 mm. However, for example, a particle having a major axis of more than 3 mm and a minor axis of less than 3 mm may pass through a sieve having an opening of 3 mm, and the dust suppressing material of the present disclosure contains some of such stone powder particles. Since it does not matter, the particle size is defined as a particle size that can pass through a sieve having a mesh of 1 to 3 mm. Further, in the dust generation suppressing material of the present disclosure, from the viewpoint of suppressing dust generation, it is preferable that the component having a particle size of less than 0.1 mm is suppressed to less than 20% by volume ratio with respect to the entire stone powder.

Further, in the dust generation suppressing material of the present disclosure, the precipitated barium sulfate may be composed of a component having an average particle size of 0.1 μm to 1 μm measured by a laser diffraction/scattering method. When the average particle size of the precipitated barium sulfate exceeds 1 μm, the larger the particle size, the more difficult it is to adhere to the surface of the particles that become sand dust components, and therefore the dust generation suppressing effect tends to decrease. Precipitable barium sulfate having an average particle size of less than 0.1 μm is not practical because it has not been industrially produced.

Further, in the dust generation suppressing material of the present disclosure, the base material is mixed with high-quality soil and stone powder in a volume ratio of 30:70 to 70:30, and 100 volume parts of the mixture of the base material and the precipitated barium sulfate is present. 1 to 10 parts by volume of precipitated barium sulfate may be included. With such a dust suppressing material, by laying the dust suppressing material on the existing surface soil, it is possible to configure a new surface soil in which dust generation is suppressed more than that of the existing surface soil. ..

Further, in the dust generation suppressing material according to the present disclosure, the good quality soil may include at least one of masato soil and mountain sand.
Further, in the dust generation suppressing material of the present disclosure, the stone powder may include at least one of limestone screenings and green screenings.

The dust generation suppressing method of the present disclosure is a new surface layer in which dust generation is suppressed more than the existing surface soil by laying a dust suppressing material on the existing surface soil in a facility equipped with the existing surface soil. A method for suppressing dust generation that constitutes soil, wherein the dust generation suppressing material is one in which precipitated barium sulfate is blended with the base material, with at least one of the high-quality soil and stone powder as the base material. The material is mixed with good quality soil and stone powder in a volume ratio of 30:70 to 70:30, and 1 to 10 parts by volume of the precipitated barium sulfate is contained in 100 parts by volume of the mixture of the base material and the precipitated barium sulfate. include.

According to the dust generation suppressing method thus configured, as described in detail in the above description of the dust generation suppressing material, by laying the dust generation suppressing material on the existing surface soil, the existing surface layer It is possible to construct a new surface soil in which dust generation is suppressed more than soil.

Further, the dust generation suppressing method of the present disclosure, in a facility equipped with an existing surface soil, by stirring and mixing the existing surface soil and the dust suppression material, dust generation is suppressed more than the existing surface soil. It is a dust generation suppressing method which constitutes a new surface soil, wherein the dust suppressing material is a mixture of sedimentary barium sulfate with respect to stone powder, and the existing surface soil and stone powder are 30:70 to 70: It is blended in a volume ratio of 30 and, in 100 parts by volume of a mixture of existing surface soil, stone powder, and sedimentable barium sulfate, 1 to 10 parts by volume of sedimentable barium sulfate is blended, so that sedimentability to stone powder is settled. The mixing ratio of barium sulfate and the mixing ratio of the dust suppression material to the existing surface soil are adjusted.

According to the dust generation suppressing method thus configured, as described in detail in the description of the dust generation suppressing material, when the existing surface soil is a component similar to the good quality soil, the existing surface soil and By stirring and mixing, a new surface soil in which dust generation is suppressed more than the existing surface soil can be formed.

FIG. 1 is an explanatory view showing the structure of the dust measuring device. FIG. 2 is a graph showing the measurement results of the dust measurement test (1). FIG. 3 is a graph showing the measurement results of the dust measurement test (No. 2). FIG. 4 is a graph showing the measurement results of the dust measurement test (No. 3). FIG. 5 is a graph showing the measurement results of the dust measurement test (Part 4).

Next, the above dust generation suppressing material will be described with reference to exemplary embodiments.
(1) Dust measurement test (1)
We made prototypes of dust control materials using three kinds of barium sulfate with different physical properties, and verified the difference in dust control effect of each dust control material. Specifically, the following Samples 1 to 4 were prepared by using mountain sand (passing through a sieve having an opening of 2 mm), which is one of the good soils, as a base material. First, as the sample 1, a sample (190 cc) containing only 95 volume parts of mountain sand was prepared. Further, as Sample 2, 5 parts by volume of sedimenting barium sulfate (average particle size 0.6 μm, product name: sedimenting barium sulfate 100, manufactured by Sakai Chemical Industry Co., Ltd.) was added to and mixed with 95 parts by volume of sand. The prepared product (200 cc) was prepared. As Sample 3, 5 parts by volume of sedimenting barium sulfate (average particle diameter 0.8 μm, product name: sedimenting barium sulfate 200, manufactured by Sakai Chemical Industry Co., Ltd.) was added to and mixed with 95 parts by volume of sand. The prepared product (200 cc) was prepared. Further, as sample 4, 5 parts by volume of effervescent barium sulfate (average particle diameter 15 μm, product name: effervescent barium sulfate BA, manufactured by Sakai Chemical Industry Co., Ltd.) was added to and mixed with 95 parts by volume of sand. (200 cc) was prepared. Since the amount of sand contained in each sample is 190 cc, the amount of sand dust component contained in each sample is the same. The average particle diameter of each barium sulfate shown in this embodiment is a value measured by a laser diffraction/scattering method (particle size distribution measuring device).

Each of these samples 1 to 4 was put into the dust measuring device 1 shown in FIG. The dust measurement device 1 includes a measurement container 3, a sample introduction unit 5, an intake unit 7, a tube 9, a digital dust meter 11 and the like. The measurement container 3 is a transparent container made of acrylic resin and has a cylindrical shape with a diameter of 39 cm and a height of 59 cm. An opening 3A is provided on the upper portion of the measurement container 3. A cylindrical support 13 is provided on the upper surface of the measurement container 3 at a position surrounding the opening 3A.

The sample input unit 5 is configured in a funnel shape and is mounted on the support base 13. The sample S is put in the sample input unit 5. When the sample S is put into the sample input unit 5, the stop paper 15 is installed inside the sample input unit 5, and the input port 5A of the sample input unit 5 is closed by the stop paper 15. As a result, in the sample loading unit 5, the sample S can be held in the sample loading unit 5 without being dropped from the loading port 5A. Further, when the stop paper 15 is pulled out from the sample loading unit 5 in a state where the sample S is loaded in the sample loading unit 5, the sample S can be dropped from the loading port 5A.

The suction part 7 is composed of a pipe material introduced from the side surface of the measurement container 3 into the measurement container 3. The cryogen that constitutes the inhalation part 7 extends substantially horizontally from the side surface of the measurement container 3 toward the center of the measurement container 3, and its tip is bent downward before reaching the center of the measurement container 3 and then downwardly. The bent tip is open. In addition, in the case of this embodiment, the suction part 7 is provided at a position 45 cm in height from the bottom surface of the measurement container 3. The tube 9 has one end connected to the suction unit 7 and the other end connected to the digital dust meter 11. The digital dust meter 11 is a commercially available device (digital dust meter LD-3K2 type, manufactured by Shibata Scientific Co., Ltd.) that measures suspended particulate matter by a light scattering method.

In the dust measuring device 1 as described above, the differences in the dust generation suppressing effect were verified by using the above-mentioned samples 1 to 4 as the sample S. In carrying out the test, each of Samples 1 to 4 was completely dried in a microwave oven (treated at 600 W for 3 minutes), and then cooled to room temperature and put in the sample charging unit 5. After that, the stop paper 15 was pulled out from the sample loading section 5, and each of the samples S1 to S4 was dropped from the loading port 5A all at once, as indicated by the solid arrow in FIG. When the dropped samples 1 to 4 reach the inner bottom surface of the measurement container 3, dust rises inside the measurement container 3 as indicated by a dashed arrow in FIG. 1. The change with time of the number was measured with the digital dust meter 11 every one minute. The measurement was performed three times on the same sample, and the average value was adopted as the measurement result. The measurement results are shown in Table 1 and FIG.

As is clear from the measurement results shown in Table 1 and FIG. 2, it was suggested that Sample 2 has the smallest amount of dust generation and a high dust generation suppressing effect. Although the sample 3 had a weaker dust generation suppressing effect as compared with the sample 2, the dust generation suppressing effect was recognized correspondingly, and the sustainability of the effect was also stable. Sample 4 also had a dust suppressing effect, but the effect was slightly lower than that of sample 3. Sample 1 resulted in an increase in the number of dusts with the passage of time, and it was clarified that dusts were not suppressed for a long time when barium sulfate was not added.

(2) Dust measurement test (2)
Dust suppression materials were prototyped by changing the compounding ratio of barium sulfate, and the dust suppression effect of each dust suppression material was verified. Specifically, in the dust measurement test (Part 1), the dust generation suppressing effect of Sample 2 was excellent, so in the dust measurement test (Part 2), the same precipitated barium sulfate (average particle size 0) as in Sample 2 was used. 0.6 μm, product name: precipitated barium sulfate 100, manufactured by Sakai Chemical Industry Co., Ltd.) was used. Using the same base material as the dust measurement test (No. 1) (that is, mountain sand (a sieve passing 2 mm sieve)), prepare samples 5 to 8 in which the amount of precipitated barium sulfate mixed with the base material was changed. Then, the effect of suppressing dust generation was verified.

Sample 5 is a sample containing only 100 parts by volume (200 cc) of mountain sand (that is, a blending amount of barium sulfate of 0%). Sample 6 is a sample obtained by adding 2.5 parts by volume (5 cc) of barium sulfate to 100 parts by volume (200 cc) of sand. Sample 7 is a sample obtained by adding 5 parts by volume (10 cc) of barium sulfate to 100 parts by volume (200 cc) of sand. Sample 8 is a sample obtained by adding 10 parts by volume (20 cc) of barium sulfate to 100 parts by volume (200 cc) of sand. Since the amount of sand contained in each sample is 200 cc, the amount of sand dust component contained in each sample is the same. With respect to Samples 5 to 8 as described above, the difference in dust generation suppressing effect was verified using the same dust measuring device 1 as in the dust measuring test (No. 1). The test procedure is the same as the dust measurement test (No. 1). The measurement results are shown in Table 2 and FIG.

As is clear from the measurement results shown in Table 2 and FIG. 3, Samples 6, 7, and 8 all generate less dust than Sample 5, and by incorporating precipitated barium sulfate, a dust generation suppressing effect is exhibited. It was suggested to do. Samples 7 and 8 have a higher dust suppressing effect than sample 6. However, since the sample 6 also has a corresponding dust suppressing effect, the required dust suppressing effect may be obtained even with the formulation like the sample 6 when the sand dust content is small. No significant difference was found between Sample 7 and Sample 8. In the case of Sample 5, the number of dusts did not converge even after the passage of time, and it was revealed that the dusts were not suppressed for a long time when barium sulfate was not mixed.

(3) Dust measurement test (Part 3)
Green screenings (crushed green metamorphic rocks (diabase)) and limestone screenings (crushed limestone), which are known as ground pavement materials used as a countermeasure for sand dust by making a prototype dust control material. .) was compared. Specifically, as the sample 9, only 100 volume parts (200 cc) of sand and sand (passing through a sieve having an opening of 2 mm) was prepared. Further, as sample 10, 5 parts by volume (10 cc) of sedimentary barium sulfate (average particle diameter 0.6 μm, product name: precipitated barium sulfate 100, Sakai Chemical Industry Co., Ltd.) was used for 100 parts by volume (200 cc) of sand. (Produced) was added and mixed to prepare a mixture. In addition, as the sample 11, 100 parts by volume (200 cc) of green screenings (passing through a sieve having an opening of 2 mm) was prepared. As the sample 12, 100 parts by volume (200 cc) of limestone screenings (passing through a sieve having an opening of 2 mm) was prepared. Further, as sample 13, Masato soil which is one of high quality soil, limestone screenings which is one of stone powder (passing through a sieve having an opening of 2 mm), and precipitated barium sulfate (average particle diameter 0.6 μm, product name) : A sample (200 cc) in which precipitated barium sulfate 100, manufactured by Sakai Chemical Industry Co., Ltd. was blended was prepared. The compounding ratio of sample 13 is 49.5 parts by volume of Masato soil, 49.5 parts by volume of limestone screenings, and 1 part by volume of precipitated barium sulfate. With respect to Samples 9 to 13 as described above, the difference in the dust generation suppressing effect was verified using the same dust measuring device 1 as in the dust measuring test (No. 1). The test procedure is the same as the dust measurement test (No. 1). The measurement results are shown in Table 3 and FIG.

As is clear from the measurement results shown in Table 3 and FIG. 4, Samples 10 and 13 in which the precipitated barium sulfate was mixed exhibited an excellent dusting suppressing effect.
(4) Field test Sample 13 described above (49 parts by volume of Masato soil, 49 parts by volume of limestone screenings, precipitated barium sulfate (average particle size 0.6 μm, product name: precipitated barium sulfate 100, manufactured by Sakai Chemical Industry Co., Ltd.) 2 parts by volume) was laid on the surface of the existing surface soil in a thickness of 5 to 10 mm, and the progress was observed. The evaluation of the effect was carried out at two facilities. At the time when one year and three months have passed, there is no problem due to dust generation.

Further, instead of the limestone screenings in the above-mentioned sample 13, sample 14 (49 volume parts of Masato soil, 49 volume parts of green screenings, precipitated barium sulfate (average particle Diameter 0.6 μm, product name: Sedimentary barium sulfate 100, manufactured by Sakai Chemical Industry Co., Ltd.) 2 parts by volume) was prepared, and sample 14 was laid on the surface of the existing surface soil in a thickness of 5 to 10 mm and the progress was observed. .. The evaluation of the effect was carried out at two facilities. At the time when one year and three months have passed, there is no problem due to dust generation.

Furthermore, a sample (Sample 15) in which 49 parts by volume of limestone screenings and 2 parts by volume of precipitated barium sulfate (average particle size 0.6 μm, product name: precipitated barium sulfate 100, manufactured by Sakai Chemical Industry Co., Ltd.) were mixed. I prepared. The sample 15 was sprinkled on the ground on which the existing surface soil mainly composed of the Masa soil was laid, and mixed with the existing surface soil to a depth of about 10 mm using an instrument. At the time of mixing, the amount of the sample 15 was adjusted so that 51 parts by volume of the sample 15 was mixed with 49 parts by volume of the existing surface soil. The evaluation of the effect was carried out at two facilities. At the time when one year and three months have passed, there is no problem due to dust generation. As described above, the existing surface soil may be used to prepare the surface soil having a mixing ratio corresponding to the above-mentioned sample 13 on site.

For comparison, settling barium sulfate (average particle size 0.6 μm, product name: settling barium sulfate 100, manufactured by Sakai Chemical Industry Co., Ltd.) was sprayed alone on the surface of the existing surface soil, and a tool of about 10 mm was used. It was mixed with the existing surface soil to the depth. During the mixing, the amount of the precipitated barium sulfate was adjusted so that 2 parts by volume of the precipitated barium sulfate was mixed with 98 parts by volume of the existing surface soil. The evaluation of the effect was carried out at two facilities. The dust suppression effect was observed for about half a year, but thereafter the effect diminished.

The reason why the effect diminished in about half a year when the sedimentable barium sulfate was sprayed alone was that the sedimentation barium sulfate was deep in the deep soil layer every time it rained due to the large difference in specific gravity between the existing surface soil and the sedimentable barium sulfate. It is probable that the sinking barium sulphate remaining near the surface of the surface soil gradually decreased. In this respect, as in Samples 13 to 15, when stone powder (that is, limestone screenings or green screenings) coexists with sedimentable barium sulfate, the stone powder and sedimentation are greater than those of surface soil mainly composed of clay minerals. Since the difference in specific gravity of soluble barium sulphate is small, it is considered that the stone powder may suppress sedimentation of precipitated barium sulphate by rainfall.

Alternatively, the above-mentioned stone powder has a particle size significantly larger than that of the precipitated barium sulfate, and is less likely to sink to the deeper layer as compared with the precipitated barium sulfate, as compared with the precipitated barium sulfate that enters even a small gap. Therefore, when the sedimentable barium sulfate adheres to the surface of the stone powder, both may integrally remain on the surface of the surface soil, and the sedimentation of the sedimentable barium sulfate to the deep layer may be suppressed. Other than this, there may be other factors that tend to leave the precipitated barium sulfate on the surface layer, but in any case, from the results of this field test, the precipitated barium sulfate was mixed by mixing stone powder. It has been revealed that the dust particles are more likely to remain in the powder, and the durability of the dust generation suppressing effect is improved.

(5) Dust measurement test (Part 4)
The following Samples 16 to 19 were prepared using, as a base material, mountain sand (mackerel soil, which passed through a sieve having an opening of 2 mm), which is one of the high-quality soils. First, as the sample 16, a sample (180 cc) containing only 90 volume parts of mountain sand was prepared. Further, as sample 17, 10 parts by volume of sedimenting barium sulfate (average particle size 0.6 μm, product name: sedimenting barium sulfate 100, manufactured by Sakai Chemical Industry Co., Ltd.) was added to and mixed with 90 parts by volume of sand. The prepared product (200 cc) was prepared. Further, as sample 18, 10 parts by volume of precipitated barium sulfate (average particle size 0.6 μm, product name: BARIACE B-55, manufactured by Sakai Chemical Industry Co., Ltd.) was added to and mixed with 90 parts by volume of sand. The thing (200cc) was prepared. The precipitated barium sulfate mixed in the sample 18 is said to have higher dispersibility in the base material than the precipitated barium sulfate mixed in the sample 17.

Further, as sample 19, 10 parts by volume of effervescent barium sulfate (average particle diameter 15 μm, product name: emissive barium sulfate BA, manufactured by Sakai Chemical Industry Co., Ltd.) was added to and mixed with 90 parts by volume of mountain sand. (200 cc) was prepared. Since the amount of mountain sand contained in each sample is 180 cc, the amount of sand dust component contained in each sample is the same. About these samples 16-19, using the same dust measuring device 1 as the dust measurement test (the 1), the difference in the dusting suppression effect was verified. The test procedure is the same as the dust measurement test (1). The measurement results are shown in Table 4 and FIG.

As is clear from the measurement results shown in Table 4 and FIG. 5, Samples 17 and 18 both generate less dust than Samples 16 and 19, and by incorporating precipitated barium sulfate, a dust generation suppressing effect is exhibited. It was suggested to do. Particularly, with respect to the sample 18 containing the precipitated barium sulfate having a higher dispersibility than the sample 17, the dust generation suppressing effect was exhibited in the sample 17 and above. Therefore, it is expected that the higher the dispersibility of the precipitated barium sulfate, the better the effect of suppressing dust generation. Therefore, in applications where a higher dust generation suppressing effect is required, it is preferable to add precipitated barium sulfate having high dispersibility. In addition, even if it is sufficient to achieve a dust generation suppressing effect to some extent, it is possible to suppress the compounding amount of the precipitated barium sulfate by blending the highly dispersible precipitated barium sulfate. Can be suppressed.

(6) Other Embodiments The dust generation suppressing material has been described above with reference to the exemplary embodiment, but the above embodiment is merely one example of one aspect of the present disclosure. That is, the present disclosure is not limited to the exemplary embodiments described above, and can be implemented in various forms without departing from the technical idea of the present disclosure.

For example, in the above-described embodiment, as an example of the stone powder, an example in which the limestone screenings or the green screenings are mixed alone has been described, but both may be mixed. Although limestone screenings and green screenings have been illustrated as examples of stone powder, crushed stone screenings (for example, black screenings) produced by crushing other rocks may be mixed as the stone powder. .. Alternatively, stone powder may be mixed with Antuker, which is produced by crushing fired soil (for example, brick).

Further, in the above embodiment, as an example of good soil, mountain sand and Masato soil are exemplified, but good quality soil other than mountain sand and Masato soil is good soil that is suitable for use as the surface soil for clay ground. Soil may be used. Examples of such high quality soil include black soil, red soil, Arakida soil, Iwase sand and the like. Which quality soil is to be used may be selected according to the required standard specified for each facility. Depending on the use of the facility, a suitable color may be taken into consideration. For example, in a baseball field, the visibility of the ball can be improved by using black clay. When black soil is used as the high quality soil, for example, it is preferable to prepare the mixture ratio such as 50 to 70 parts by volume of black soil, 25 to 45 parts by volume of stone powder, and 5 parts by volume of precipitated barium sulfate.

Further, in the above-described embodiment, the limestone screenings are used as the base material, and the dust suppressing material (Sample 15) mixed with the sedimentary barium sulfate is applied to the ground on which the existing surface soil mainly composed of the Masa soil is laid. Although an example is shown, if the facility has an existing surface soil mainly composed of crushed stone screenings, a dust suppressing material having a good quality soil as a base material may be applied. That is, depending on the composition of the existing surface soil, the composition of the dust suppressing material to be mixed therein may be prepared. As the composition of the surface soil after the mixing of the dust suppressing material, high-quality soil and stone powder are 30:70. It is preferable that 1 to 10 parts by volume of the precipitated barium sulfate is contained in 100 parts by volume of the mixture of the high-quality soil, stone powder and the precipitated barium sulfate, which is blended in a volume ratio of 70:30.

Further, in addition to the above dust generation suppressing material, and the dust generation suppressing method, the ground in which the dust generation suppressing material is laid, the playground in which the dust generation suppressing material is laid, the coat in which the dust generation suppressing material is laid, The present disclosure can also be realized in various forms such as a school yard on which the dust generation suppressing material is laid.

DESCRIPTION OF SYMBOLS 1... Dust measuring device, 3... Measuring container, 3A... Opening part, 5... Sample input part, 5A... Input port, 7... Suction part, 9... Tube, 11... Digital dust meter, 13... Support stand, 15... Stop paper.

Claims (9)

In a facility equipped with existing surface soil, dust is suppressed more than the existing surface soil by being laid on the existing surface soil, or by mixing and mixing with the existing surface soil. Is a dust generation suppression material that can form various surface soils,
At least one of high-quality soil and stone powder is used as a base material, and sedimentary barium sulfate is mixed with the base material. The dust suppression material according to claim 1,
The base material contains the good quality soil,
The quality soil has a particle size that can pass through a sieve having an opening of 4 to 8 mm, and a component having a particle size of less than 0.1 mm is suppressed to less than 20% by volume ratio with respect to the entire quality soil. Dust suppressor. The dust suppressing material according to claim 1 or 2,
The base material contains the stone powder,
The stone powder has a particle size capable of passing through a sieve having an opening of 1 to 3 mm, and a component having a particle size of less than 0.1 mm is suppressed to less than 20% by volume ratio with respect to the entire stone powder. Material. The dust suppressing material according to any one of claims 1 to 3,
The above-mentioned precipitated barium sulfate is a dust-inhibiting material, which is composed of components having an average particle diameter of 0.1 μm to 1 μm measured by a laser diffraction/scattering method. The dust suppressing material according to any one of claims 1 to 4,
The high-quality soil and the stone powder are mixed in the base material at a volume ratio of 30:70 to 70:30,
A dust generation suppressing material, wherein 1 to 10 parts by volume of the precipitated barium sulfate is contained in 100 parts by volume of the mixture of the base material and the precipitated barium sulfate. The dust suppressing material according to any one of claims 1 to 5,
The high-quality soil is a dust suppressing material containing at least one of Masa soil and mountain sand. The dust generation suppressing material according to any one of claims 1 to 6,
The above-mentioned stone powder is a dust generation suppressing material containing at least one of limestone screenings and green screenings. In a facility equipped with existing surface soil, by laying a dust suppression material on the existing surface soil, dust suppression that constitutes a new surface soil in which dust generation is suppressed more than the existing surface soil Method,
The dust generation suppressing material, of the high-quality soil and stone powder, at least one of the base material, a precipitable barium sulfate is mixed with the base material, the base material, the high-quality soil and the Stone powder is mixed in a volume ratio of 30:70 to 70:30, and 1 to 10 parts by volume of the precipitated barium sulfate is contained in 100 parts by volume of the mixture of the base material and the precipitated barium sulfate. Dust suppression method. In facilities having a existing topsoil, stirring the surface soil and dusting suppressor of the existing, by mixing, dust constituting a new surface soil dust was suppressed than surface soil of the existing A suppression method,
The dusting suppressant is a mixture of sedimentary barium sulfate with respect to stone powder, and the existing surface soil and the stone powder are mixed at a volume ratio of 30:70 to 70:30 to obtain the existing surface layer. A mixing ratio of the precipitated barium sulfate to the stone powder, such that 1 to 10 parts by volume of the precipitated barium sulfate is mixed in 100 parts by volume of a mixture of soil, the stone powder, and the precipitated barium sulfate. And a mixing ratio of the dust suppressing material to the existing surface soil is adjusted.

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