JP6773323B2 - Dry separation method of volcanic ejecta deposit minerals, dry separation device of volcanic ejecta deposit minerals, manufacturing method of fine aggregate and volcanic glass material - Google Patents

Description

The present invention relates to a dry separation method for dry separation of volcanic ejecta deposit minerals, for example, ordinary shirasu, a dry separation device, and a method for producing fine aggregate and volcanic glass material obtained by the dry separation method.

Conventionally, natural sand such as river sand and sea sand has been used as fine aggregate for concrete, but river sand has been depleted as a result of over-the-counter digging, and the collection of sea sand causes environmental destruction. The collection is restricted because it is connected. Therefore, some fine aggregates for concrete have to be imported. This is especially serious in western Japan, which is highly dependent on sea sand, and the acquisition of raw materials to replace natural sand is an urgent issue.

By the way, Shirasu is one of the volcanic ejecta sedimentary minerals widely distributed in Southern Kyushu and is a resource that can be obtained in large quantities. Therefore, if Shirasu can be used as an aggregate for concrete, it will be a substitute for natural sand. obtain. In particular, unsalted sand such as river sand contributes to extending the life of concrete, especially reinforced concrete, so it has higher added value than sea sand, which is inevitably mixed with salt. However, collecting river sand is a collection of freshwater organisms and aquatic plants. It causes the destruction of the ecosystem such as, and has a large environmental load. Since Shirasu is a pyroclastic flow deposit on land about 30,000 years ago and is unsalted, the fine aggregate extracted from Shirasu has high added value as unsalted sand.

As a fine aggregate for concrete, ordinary shirasu, that is, shirasu plateau in southern Kyushu, is formed, and the biggest problem when using unprocessed shirasu as it is is "Shirasu" supervised by the Civil Engineering Department of Kagoshima Prefecture. According to "Concrete Construction Manual (Draft)" (issued in 2006), Shirasu contains an extremely large amount of fine particles. The content of fine particles having a particle size of 0.150 mm or less in ordinary shirasu is in the range of 20 to 40%, and is about 30% on average, which is abnormally large as compared with natural sand. The large amount of fine particles is derived from the fact that Shirasu is a huge pyroclastic flow deposit that is not normally selected by water, unlike river sand that has been selected by water. According to the Japan Society of Civil Engineers "Concrete Standard Specification", the particle content of ordinary sand with a particle size of 0.150 mm or less should be 10% or less, and the content of crushed sand and blast furnace slag crushed sand should be 15% or less. Since it is said that it can be done, ordinary slag cannot be used as it is for ordinary sand. If a fine aggregate containing a large amount of fine particles having a particle size of 0.150 mm or less is used, the fluidity of fresh concrete that has not yet hardened is hindered, leading to an increase in the unit water amount. For this reason, it is necessary to remove fine particles having a particle size of 0.150 mm or less, preferably to 15% or less, which is the same as crushed sand, or at least less than 15%, but the removal requires a great deal of cost and is costly. In order to become, it could not be realized so far.

That is, there are a dry sieving method and a wet sieving method for removing fine particles having a particle size of 0.150 mm or less from the silas. However, if the former is performed while the silas remains undried, the contained moisture adheres to the particles. Moisture may seep out due to vibration during the sieving process, so the fine particles may aggregate or adhere to the coarse particles and also adhere to the sieve net, causing the sieving. It causes clogging and makes it impossible to remove fine particles. Therefore, it is necessary to dry it before sieving, but it requires a large amount of energy consumption and a long processing time, which is unavoidably a major obstacle to practical use. In addition, the latter wet sieving method has the same disadvantages as the former because it requires the use of a large amount of water and requires a drying treatment after sizing.

Another problem in sizing the shirasu is the problem of disposal of the removed fine particles having a particle size of 0.150 mm or less, that is, unnecessary residues. According to JIS-A1204 "Soil particle size test method", particle size 2 to 4.75 mm is fine gravel, particle size 0.850 to 2 mm is coarse sand, and particle size 0.250 to 0.850 mm is medium sand. Minutes, particle size 0.075 to 0.250 mm is defined as fine sand, particle size 0.005 to 0.075 mm is defined as silt, and particle size 0.005 mm or less is defined as clay. Therefore, the fine particles having a particle size of 0.150 mm or less have a wide particle size distribution, a part of fine sand, silt, and clay are mixed, and the added value is low, so that there is no use for them. Of the silt and clay, especially clay has fine particles that are difficult to settle in water, so it cannot flow into rivers or the sea while remaining cloudy, and the settling speed is increased by using a costly flocculant in a pond. It is necessary to dispose of the particles that have been separated by sedimentation, and the disposal cost cannot be ignored. In addition, since the wastewater of the supernatant is also mixed with a coagulant component, it is not environmentally preferable to discharge it into the natural environment. Clay, silt, and clay aggregates once soaked in water solidify during the drying process, and when used, they are dispersed in single particles even if they are to be used. Since it is difficult, even if it is used as an admixture or the like, the agglomerated structure interferes with it, and it is difficult to exhibit the pozzolan effect that may originally be present. Further, when the component of the coagulant is mixed, the effect as an admixture is reduced.

Adjusting to the desired particle size is called sizing, but when shirasu is usually sized and divided into two parts based on the particle size of 0.150 mm as described above, even if one of them is useful as a product, the other Unnecessary residue is generated and the disposal cost is passed on to the product, which is disadvantageous in price competition. In addition, if the number of divisions by sizing is small, the particle size range naturally becomes wide and the added value becomes low, so that it is not profitable.

Therefore, with the exception of shirasu, such as Yoshida shirasu and Kakuto shirasu, which have a very small amount of resources and have a fine particle size due to the natural selection action of water, the ordinary shirasu that forms the shirasu plateau is industrially The current situation is that it is not profitable if the grains are sized.

Regarding the method of sizing ordinary silas, the first cyclone or the fourth cyclone and the bag filter are combined, and the first cyclone is the fine aggregate, the second cyclone is the coarse sand and the middle sand, and the third cyclone is the middle sand. There is also a method of recovering fine sand, fine sand and silt with a fourth cyclone, and clay with a bag filter (Patent Document 1).

Japanese Unexamined Patent Publication No. 2010-269951 (Claims and others)

The sizing method described in Patent Document 1 is made from volcanic ejecta sedimentary minerals without drying the raw material silas or the product, which is complicated and consumes a large amount of heat energy, or elutriation treatment using a large amount of water. It is possible to easily and efficiently mass-produce a large number of types of high-value-added sizing substances adjusted to a desired particle size at the same time. However, the yield of fine aggregate recovered by the first cyclone, which is usually made from shirasu, is low and the yield is increased as it is, which has a density of 2.5 g / cm ³ or more specified by "sand" of JIS A5308. Therefore, further improvement was required.

The present invention provides a dry separation method for volcanic ejecta sedimentary minerals, which is an improvement of the conventional shirasu sizing method and can increase the yield of fine aggregate having a density of 2.5 g / cm ³ or more. The purpose is.

The present inventor removes gravel having a large particle size from volcanic ejecta sedimentary minerals such as ordinary silas, and then dry-separates them with a device combining a specific wind sorter and a specific gravity difference sorter. , It was found that the yield of fine aggregate having a density of 2.5 g / cm ³ or more can be increased, and the present invention was made based on this finding.

In the dry separation method of volcanic ejecta deposit minerals of the present invention, the balance obtained by removing gravel from volcanic ejecta deposit minerals is supplied to at least one kind of wind power sorter selected from a circulation type wind power sorter and a blow-up type wind power sorter. Then, divide it into two parts, one for coarse particles and the other for non-coarse particles.
The coarse particles are supplied to an air table type specific gravity difference sorting device that blows air from below toward the perforated plate while vibrating the perforated plate inclined at a predetermined angle from the horizontal direction, and from the upper end of the perforated plate. It is characterized in that the selected material is collected as fine aggregate.

In the dry separation method of volcanic ejecta sedimentary minerals of the present invention, those selected from the lower end of the perforated plate can be recovered as pumice stones, and those blown up from the perforated plate are further cyclone-type classifiers. Can be sorted into fine particles and fine powder. Further, the opening of the perforated plate is preferably 0.1 to 0.25 mm, and it is preferable to further sort the coarse particles other than the coarse particles into fine particles and fine powder by a cyclone type classifier.

The dry separation device for volcanic ejecta deposit minerals of the present invention is a circulating wind power sorter and a blow-up device that supplies the balance after removing gravel from volcanic ejecta deposit minerals and sorts them into coarse particles and non-coarse particles. At least one type of wind sorter selected from the type wind sorters,
An air table to which coarse particles sorted by the circulation type wind power sorter or a blow-up type wind power sorter are supplied, and air is blown from below toward the perforated plate while vibrating a perforated plate inclined at a predetermined angle from the horizontal direction. Equipped with a specific gravity difference sorting device of the formula,
The specific gravity difference sorting device is characterized in that fine aggregates are sorted from the upper end of the perforated plate.

In the dry separation device for volcanic ejecta sedimentary minerals of the present invention, pumice stones can be sorted from the lower end of the perforated plate, and those blown up from the perforated plate are sorted into fine particles and fine powders. More machines can be provided. Further, it is preferable that the perforated plate has a mesh size of 0.1 to 0.25 mm, and it is preferable to further provide a cyclone type classifier that sorts the coarse particles other than the coarse particles into fine particles and fine powder.

The method for producing a fine aggregate of the present invention is characterized in that the fine aggregate is obtained by the dry separation method of the volcanic ejecta sedimentary mineral of the present invention described above.
The method for producing pumice of the present invention is characterized in that pumice is obtained by the dry separation method of the volcanic ejecta sedimentary mineral of the present invention described above.
The method for producing a fine-grained volcanic glass material of the present invention is characterized in that a fine-grained volcanic glass material is obtained by the dry separation method of the volcanic ejecta deposit mineral of the present invention described above.
The method for producing a fine powder volcanic glass material of the present invention is characterized in that a fine powder volcanic glass material is obtained by the dry separation method of the volcanic ejecta deposit mineral of the present invention described above.

According to the present invention, the yield of fine aggregate having a density of 2.5 g / cm ³ or more can be increased as compared with the conventional sizing method. In addition, a large amount of raw materials can be processed to obtain a high-quality recovered product having a desired particle size and density in various types. For example, ordinary shirasu can be dry-separated to recover fine aggregates, pumice stones, fine-grained volcanic glass materials, and fine-grained volcanic glass materials. Pumice stone is used as a lightweight aggregate, fine-grained volcanic glass material is used as a pearlite raw material or silas balloon raw material, and finely powdered volcanic glass material is used as an admixture material or an admixture having a pozzolan effect or a mixed cement raw material having a pozzolan effect. It is possible to collect each of the high-priced items, and the effective use of ordinary glass is achieved. The volcanic glass material can be used as a raw material for hydraulic lime and cement as well as a raw material for ceramics. In other words, the present invention provides fine aggregates, lightweight aggregates, pearlite, pearlite raw materials or silas balloon raw materials, admixture raw materials or pozzolan effect by dry separation of volcanic ejecta deposit minerals such as ordinary silas. It is a production method capable of producing an admixture having a pozzolan effect, a mixed cement raw material having a pozzolan effect, a hydraulic lime raw material, a cement raw material, and a ceramic raw material.

It is the schematic of an example of the dry type separation apparatus which carries out the dry type separation method of this invention. It is the schematic of an example of the dry type separation apparatus of the modification of FIG. It is a schematic diagram explaining the principle of a specific gravity difference sorting apparatus. It is the schematic of an example of the dry type separation apparatus which carries out the dry type separation method of this invention. It is the schematic of an example of the dry type separation apparatus which carries out the dry type separation method of this invention. It is the schematic of an example of the dry type separation apparatus which carries out the dry type separation method of this invention.

Hereinafter, according to the drawings, the embodiment of the dry separation method for volcanic ejecta deposit minerals, the dry separator, the method for producing fine aggregates and volcanic glass materials of the present invention will be described using ordinary silas, which is a kind of volcanic ejecta deposit minerals, as a raw material. The example used in the above will be described.

(Embodiment 1)
An embodiment of a dry separation method and apparatus for volcanic ejecta sedimentary minerals of the present invention will be described.
FIG. 1 is a schematic view showing an example of a dry separation device suitable for use in the dry separation method of the present invention. The volcanic ejecta sedimentary mineral separated by the dry separator of the present invention is, for example, ordinary shirasu. Therefore, volcanic ejecta sedimentary minerals will be described below using the example of ordinary Shirasu.
The dry separator 1 shown in FIG. 1 includes a wind power sorter 11 and a specific gravity difference sorter 21.

The wind power sorter 11 is a device that puts an object to be sorted into a sorting column while blowing wind with a blower, and separates a thing having a floating speed higher than the wind speed and a thing having a floating speed lower than the wind speed. A sorting column is a space in a circular, square, or rectangular tube with a constant cross-sectional area, a constant-velocity updraft that minimizes the pulsating current of the wind, and is a part that sorts by utilizing the difference in the floating speed of particles. Point to. In general, the wind power sorter includes a circulation type wind power sorter, a blow-up type wind power sorter, a suction type wind power sorter, and the like, and the dry separation method of the present invention can be divided into coarse particles and non-coarse particles. Basically, any type of wind power sorter can be used. However, among the wind power sorters, the suction type wind power sorter requires about twice as much power as the blow-up type wind power sorter, which may increase the cost of dry separation. On the other hand, both the circulation type wind power sorter and the blow-up type wind power sorter use a sirocco fan of a multi-blade fan for blowing air, and this sirocco fan can generate an air flow with less pulsating current in the sorting column. Since it can be selected, high-precision sorting is possible. Therefore, the wind power sorter in the present invention is at least one kind of wind power sorter selected from the circulation type wind power sorter and the blow-up type wind power sorter. The blower fan of the circulation type wind power sorter or the blow-up type wind power sorter in the present invention is not limited to the sirocco fan, and may be any device that generates an air flow with little pulsating current. Further, a blower fan equipped with a rectifying device that realizes a uniform surface velocity of the airflow in the sorting column may be used.

The wind power sorter 11 of the present embodiment shown in FIG. 1 is an example of a circulation type wind power sorter. The circulation type wind power sorter is a sorter that is blown by a sirocco fan 11a and has a circulation path between the sorting column 11b and the diffusion chamber 11c. In general, the circulation type wind power sorter can reduce the power as compared with the blow-up type wind power sorter in which the object to be sorted does not have a circulation path between the sorting column and the diffusion chamber. Therefore, in terms of cost, the dry separation method of the present invention is used. It is preferable to use it in. There are two types of circulating wind power sorters: a closed type that does not introduce outside air with a built-in sirocco fan and an outside air introduction type that introduces outside air with a built-in sirocco fan. In the present invention, both the closed type and the outside air introduction type can be used. it can. FIG. 1 shows an example of a closed type circulating wind power sorter.

The rest of the ordinary shirasu from which the gravel has been removed is quantitatively supplied to the wind power sorter 11 from the supply port 11d, divided into coarse particles and non-coarse particles, and the coarse particles are discharged from the first discharge port 11e. Then, the components other than the coarse particles are discharged from the second discharge port 11f. It is preferable that the gravel removed before being supplied to the wind power sorter 11 has a particle size of more than 5 mm from the viewpoint of operational efficiency and operational stability of the wind power sorter 11. Specifically, in the illustrated dry separator, ordinary silas is supplied from the belt feeder 3a to the sieve 4a, and the sieve 4a removes gravel having a particle size of more than 5 mm as an upper sieve, and the balance is as a lower sieve. It is supplied to the wind sorter 11 by the belt feeder 5a. In the illustrated example, a sieve 4a is used to remove gravel having a particle size of more than 5 mm, but instead of the sieve 4a, a machine for crushing the particle size of the raw material, ordinary shirasu, to 5 mm or less may be used. it can. Further, by crushing using a machine that crushes the pumice stone to 5 mm or less, the inside of the pumice stone normally contained in Shirasu is exposed, and there is an advantage that the whiteness of the pumice stone product separated and recovered is improved. Small pumice stones and volcanic glass particles from which crushed pumice stones have been recovered have an exposed glass surface inside the pumice stone particles, and are equivalent to foamed pumice stones produced by firing and expanding and foaming, and pearlite of approximately 0.15 mm or more. There is an advantage that the whiteness of the product and the silas balloon of about 0.15 mm or less is higher than that of pumice stones that have not undergone the crushing process, foamed pumice stones derived from volcanic glass particles, pearlite equivalent products, and silas balloon equivalent products. is there.

By reducing the water content of the raw material to about 2% or less before separating the gravel with the sieve 4a, the dry separation method and the dry separation device of the present embodiment can be efficiently carried out. For example, the reduction of the water content of the raw material can be considered, for example, forced drying by a dryer. Even if you do not spend a lot of money to dry the moisture content to less than 2% by this forced drying, spread it indoors where sunlight shines for several centimeters, leave it for several days or more, and turn it upside down at regular intervals. The dry separation method and the dry separation device of the present embodiment are made more efficient by drying the raw material to some extent by another economical drying means such as drying by reducing the water content of the raw material ordinary shirasu to about 2% or less. Can be done well. Here, even when the water content of the raw material ordinary shirasu exceeds 2%, the dry separation method and the dry separation device of the present embodiment can be carried out, but the separation is performed as compared with the sufficiently dried raw material of ordinary shirasu. The efficiency is reduced, and the higher the water content of the raw material, ordinary shirasu, the lower the separation efficiency.

Sorting by the wind power sorter 11 into two parts, that is, the coarse particle content and the non-coarse particle content, can be performed by adjusting the wind speed by the sirocco fan 11a with the rotation speed or the like. Here, the non-coarse particles have a particle size of less than about 0.30 mm, and the coarse particles have a larger particle size than the non-coarse particles, specifically, about 0.3 mm or more. More specifically, the particle size is about 0.30 to 5 mm. That is, the wind speed sorter 11 divides the ordinary shirasu from which the gravel has been removed into coarse particles with a particle size of about 0.30 mm as a reference and halves with less than that. Etc. are adjusted. Then, substantially all of the components that can be fine aggregates are contained in the coarse particles, and most of the fine grains that are normally contained in Shirasu can be separated from the components that can be fine aggregates. .. It is not necessary to strictly classify the silas into those having a particle size of less than about 0.30 mm and those having a particle size of about 0.30 mm or more by the wind sorter 11, and those having a coarse grain size of less than about 0.30 mm. May be included to some extent. In particular, heavy minerals having a large specific gravity even if they are less than 0.30 mm are easily distributed to coarse particles and are effective as fine aggregate components. It is impossible to completely sort the particle size with the wind power sorter 11, and a small amount of fine particles are mixed in the coarse particles. Fine particles of less than about 0.30 mm contained in the coarse particles are separated by the specific gravity difference sorting device 21 described later. In short, the wind power sorter 11 is used for a process of removing most of the fine particles from ordinary shirasu in order to improve the separation efficiency of the specific gravity difference sorting device 21 described later and to prevent clogging of the perforated plate. ..

The coarse particles sorted by the wind power sorter 11 are supplied to the specific gravity difference sorting device 21 described later via the belt feeder 6. When the sorting capacity of the specific gravity difference sorting device 21 is larger than the amount of coarse particles recovered by the wind power sorting machine 11, the coarse particles of the wind power sorting machine 11 are temporarily stored and supplied to the specific gravity difference sorting device 21 on a separate line. You can also do it.

Further, as shown in the dry separator 2 of the modified example in FIG. 2, the belt feeder 6 is made by making the amount of coarse particles recovered by the wind power sorter 11 and the sorting ability of the specific gravity difference sorting device 21 the same. Can be omitted.

Since the coarse particle content contains almost all of the components that can be fine aggregate, from the viewpoint of recovering the fine aggregate from ordinary shirasu, except for the coarse particle content selected by the wind power sorter 11. It is not always necessary. However, except for the coarse particles, it is made of volcanic glass material, and in order to separate fine particles and fine powder and effectively utilize them, they can be classified by a cyclone type classifier described later.

The dry separation device shown in FIG. 1 includes an air table type specific gravity difference sorting device 21. The specific gravity difference sorting device 21 has a perforated plate 21a and a vibrating device 21g, and the perforated plate 21a inclined at a predetermined angle from the horizontal direction is vibrated by the vibrating device 21g, and the wind cylinder 21h is directed toward the perforated plate 21a from below. This is an air table type specific gravity difference sorting device that blows air by the blower fan 21b inside. The principle of the specific gravity difference sorting device 21 will be described with reference to the schematic diagram shown in FIG.

The perforated plate 21a is inclined at a predetermined angle from the horizontal direction. The upper surface of the perforated plate 21a has a corrugated or saw-blade-like uneven cross section, and the height difference of the unevenness is approximately 3 to 10 mm. Further, the perforated plate 21a has a large number of holes having a predetermined shape. The perforated plate 21a is capable of a unique vibrating motion with a unique anteroposterior length of ± 3 to 7 mm that can be sent out in a cycloid or a curved shape similar to it and immediately retracted from the lower side to the upper side by the vibrating device 21g using an eccentric crank. There is, and it is possible to apply a force to push upward the specific gravity component caught in the corrugated or saw blade-shaped recess. While vibrating the perforated plate 21a by the vibrating device 21g, it is possible to blow air toward the hole of the perforated plate 21a by the blower fan 21b in the wind cylinder 21h. When a mixture of a plurality of specific gravity powder particles is supplied to the upper surface of the perforated plate 21a, the heavy powder particles having a specific gravity (indicated by black circles in FIG. 3) are caught by the corrugation or saw blade-like unevenness on the upper surface of the perforated plate 21a. , The vibration of the perforated plate 21a by the vibrating device 21g causes the perforated plate 21a to move toward the upper side. The powder particles having a light specific gravity are blown up by the air flow through the holes of the perforated plate 21a. Among the powder particles having a relatively heavy specific gravity, the particles having a relatively heavy specific gravity (indicated by white circles in FIG. 3) move toward the lower side of the perforated plate 21a. Among the powders having a relatively light specific gravity, the powders having a relatively light specific gravity (shown at the midpoint in FIG. 3) are carried out of the specific gravity difference sorting device 21 by the air flow.

Therefore, the coarse particles sorted by the wind power sorter 11 are supplied to the specific gravity difference sorting device 21, and the perforated plate 21a is vibrated and blown from below toward the perforated plate 21a. It is possible to select the specific gravity content from the end on the side and the light specific gravity from the end on the lower side. Further, among the coarse particles supplied to the perforated plate 21a, those having a small particle size mixed by being unable to be sorted by the wind power sorter and adhering to the coarse particles (hereinafter referred to as "dust collector") are blown. Ascends from the perforated plate 21a. The opening of the perforated plate 21a is adjusted to 0.1 to 0.25 mm, preferably 0.15 mm so that none of the coarse particles fall through the holes of the perforated plate 21a. .. When the opening is 0.1 to 0.25 mm, the coarse-grained normal shirasu particles having a particle size of approximately 0.30 to 5 mm are less likely to be clogged, so that the reduction in processing capacity due to clogging of the perforated plate 21a is suppressed. be able to. In the dry separation treatment method and apparatus of the present invention, the coarse particles in which fine particles have been previously separated by the wind power sorter 11 are processed by the porous plate 21a, so that the porous plate 21a is clogged with the fine particles normally contained in Shirasu. It is suppressed.

For the perforated plate 21a, the working conditions are set so that those having a density of 2.5 g / cm ³ or more among ordinary shirasu are selected as the specific gravity. The working conditions are set, for example, the amount of raw material supplied per hour, the amount of air blown, the inclination angle of the perforated plate 21a, the size of the holes of the perforated plate 21a, the shape of the holes, the number of holes, the shape of the unevenness of the perforated plate, and the perforated plate. This is done by adjusting at least one of the frequency of 21a, the amount of sucked air related to the exhaust port 21e, and the like. In order to adjust the suction air volume of the discharge port 21e, it is also effective to install a flow rate control valve in the conduit 7A to adjust the suction air volume. It is also effective to install a rotary valve or a rocker valve at the connecting portion of the discharge port 21c and the discharge port 21d in order to continuously collect the fine aggregate and the pumice stone during operation.

The specific gravity content sorted by the perforated plate 21a is discharged from the discharge port 21c of the specific gravity difference sorting device 21 and collected. The recovered specific gravity content is 2.5 g / cm ³ or more in density. This weight specific gravity satisfies the density of 2.5 g / cm ³ or more specified by "sand" of JIS A5308, and can be used as it is as a fine aggregate.

The light specific gravity component sorted by the perforated plate 21a is discharged from the discharge port 21d of the specific gravity difference sorting device 21. The discharged light specific gravity contains pumice stones having a particle size of 0.3 mm or more. This pumice stone having a particle size of 0.3 mm or more is useful as a lightweight aggregate.

The dust collector floating from the perforated plate 21a is guided to the cyclone type classifier 22 via the pipeline 7A connected to the discharge port 21e of the specific gravity difference sorting device 21. Further, the coarse particles other than the coarse particles previously sorted by the wind power sorter 11 are sucked together with the surrounding air from the discharge port 11f of the wind power sorter 11 and guided to the cyclone type classifier 22 via the pipeline 17.
The discharge port 11f of the wind power sorter 11 and the cyclone type classifier 22 may be directly connected by a pipeline 17. As shown in FIG. 2, when the discharge port 11f of the wind power sorter 11 is directly connected to the conduit 17, a flow rate adjusting valve 17a for adjusting the suction amount to the conduit 17 is installed to adjust the suction amount. As a result, the separation efficiency of the wind power sorter 11 can be maintained.

The cyclone type classifier 22 shown in FIGS. 1 and 2 separates the dust collector from the specific gravity difference sorter 21 and the coarse particles from the wind power sorter 11 into fine particles and fine particles other than fine particles. Classify. The fine particles have a particle size of 0.05 to 0.30 mm. The value of the particle size of the fine particles classified by the cyclone type classifier 22 is 0.05 to 0.30 mm, which is an approximate value.

The pipeline connected below the cyclone type classifier 22 has two on-off valves 22b. During the operation of the illustrated dry separator, the fine granules deposit in the pipeline connecting below the cyclone classifier 22. In order to continuously collect the fine particles during operation, the upper on-off valve 22b is first opened and the lower on-off valve 22b is closed, whereby the fine particles are separated from the upper on-off valve 22b and the lower on-off valve 22b. Then drop it in between, then close the upper on-off valve 22b and open the lower on-off valve 22b, thereby collecting the fine particles between the upper on-off valve 22b and the lower on-off valve 22b. Here, a rotary valve or a rocker valve having the same function can be used instead of the on-off valve 22b.

The recovered fine particles are mainly volcanic glass with a particle size of less than 0.3 mm. In particular, when the volcanic ejecta deposit mineral is shirasu as in the present embodiment, the volcanic glass material having a particle size of less than 0.3 mm foams by heating, and is therefore useful as a pearlite raw material or a shirasu balloon raw material. Further, it can be used as an admixture by crushing a volcanic glass material having a particle size of less than 0.3 mm.

As the overflow portion of the cyclone type classifier 22, fine powder other than fine particles is guided to the bug filter 16 via the pipe line 17I. The bug filter 16 collects fine powder. The fine powder has a particle size of 0.05 mm or less. The value of the particle size of the fine powder of 0.05 mm or less is an approximate value. The fine powder is mainly made of volcanic glass and is useful as a mixed cement raw material having a pozzolan effect, more specifically, an admixture or a raw material thereof. Here, the portion of the bug filter 16 functions in the same manner even if it is replaced with an electrostatic precipitator. An on-off valve 16b is installed under the bug filter 16 in order to continuously collect the fine powder collected by the bug filter during operation. The on-off valve 16b has the same function as the on-off valve 22b. A rotary valve or rocker valve having the same function can be used instead of the on-off valve 16b.

An exhaust blower 18 is connected to the bag filter 16, and the airflow that has passed through the filter cloth of the bag filter 16 is discharged as exhaust J by the exhaust blower 18.

According to the dry separation method and the dry separation device of the present embodiment shown in FIG. 1, the combination of the wind power sorter 11 and the specific gravity difference sorter 21 makes ordinary shirasu a heavy specific gravity component, a light specific gravity component, fine particles and fine powder. Can be separated into. Heavy specific gravity fraction, since substantially corresponding to the density 2.5 g / cm ³ or more fine aggregates, density by collecting heavy specific gravity fraction is high and 2.5 g / cm ³ or more fine aggregate yield Can be obtained at. In addition, the volcanic glass material normally contained in Shirasu can be classified into pumice stones, fine particles and fine powders, and can be utilized for each purpose.

The need to divide volcanic glass into three types is that pumice can be used as a lightweight aggregate, and fine granules and fine powder have different suitable uses. The fine particles can be fired as they are and used as raw materials for shirasu balloons and pearlite, and when crushed, they can be used as admixtures, hydraulic lime, cement raw materials, and ceramic raw materials. Fine powder is not suitable as a raw material for shirasu balloons because its particle size is too fine, but it can be used as an admixture, hydraulic lime, cement raw material, and ceramic raw material without crushing. As a result of evaluating the performance of the admixture in the latter two fields of application, it has been confirmed that the crushed fine particles have a better pozzolan effect than the uncrushed fine powder. .. Further, as a raw material for hydraulic lime and a raw material for ceramics, fine powder is more suitable than fine particles.

From the above, it is necessary to sort ordinary shirasu into fine aggregate components and volcanic glass material, and further sort volcanic glass material into pumice stone, fine particles and fine powder in order to turn ordinary shirasu into an industrial resource. In order to realize this, we have found the present invention in which a wind power sorter and a specific gravity difference sorter are combined.

In the prior art, regarding the sizing of ordinary shirasu, the reason why it is practically difficult to sizing ordinary shirasu is described in the "Concrete Construction Manual (Draft) Using Shirasu as Fine Aggregate" published in 2006. Since we are proposing a method of using ordinary shirasu that does not remove dust with a particle size of 0.15 mm or less, it has become common knowledge that sizing of ordinary shirasu is not profitable. With the invention, it was possible to simultaneously produce many types of high-value-added shirasu at low cost.

(Embodiment 2)
An embodiment of a dry separation method and apparatus for volcanic ejecta sedimentary minerals of the present invention will be described with reference to FIG.
FIG. 4 is a schematic view showing an example of the dry separation device 3 used in the dry separation method of the present invention. In FIG. 4, the same members as described above with reference to the drawings are designated by the same reference numerals, and duplicate description will be omitted below.

The dry separator 3 shown in FIG. 4 sucks other than the coarse particles of the wind power sorter 11 from the discharge port 11f of the wind power sorter 11 together with the surrounding air, passes through the pipeline 17, and is the first cyclone type classifier. It is guided to 22A, and the dust collected from the perforated plate 21a of the specific gravity difference sorting device 21 is guided to the second cyclone type classifier 22B via the pipeline 7A connected to the discharge port 21e of the specific gravity difference sorting device 21. The discharge port 11f of the wind power sorter 11 and the cyclone type classifier 22A may be directly connected by a pipeline 17. In the case of direct connection, the separation efficiency of the wind power sorter 11 can be maintained by installing a flow rate adjusting valve 17a for adjusting the suction amount to the conduit 17 and adjusting the suction amount. The cyclone type classifiers 22A and 22B can have the same structure as the cyclone type classifier 22 described above.

In the wind power sorter 11, in order to reduce the pulsating current of the air flow in the sorting column 11b, it is necessary to control the amount of intake air to the conduit 17 connected to the cyclone type classifier 22 with high accuracy. Further, it is known that the separation performance of the specific gravity difference sorting device 21 is also affected by the amount of sucked air related to the discharge port 21e. Therefore, if the cyclone type classifiers 22A and 22B, the bug filters 16A and 16B, and the exhaust blowers 18A and 18B can be operated independently by the wind power sorter 11 and the specific gravity difference sorter 21, high-precision specific gravity separation becomes possible. .. Therefore, in this embodiment, one set of a cyclone type classifier 22B, a bug filter 16B, and an exhaust blower 18B is added to the specific gravity difference sorting device 21 of FIG. This enables highly accurate sorting and separation.

(Embodiment 3)
An embodiment of a dry separation method and apparatus for volcanic ejecta sedimentary minerals of the present invention will be described with reference to FIG.
FIG. 5 is a schematic view showing an example of a dry separation device 4 used in the dry separation method of the present invention. In FIG. 5, the same members as described above with reference to the drawings are designated by the same reference numerals, and duplicate description will be omitted below.

The dry type separator of the present embodiment is different from the first and second embodiments in which the closed type circulating wind power sorter 11 is used in that the wind power sorter is the outside air introduction type circulating wind power sorter 12. ing. Since the outside air is introduced by the sirocco fan 11a, the circulation type wind power sorter 12 has rocker valves 12g arranged at the raw material supply port 12d and the discharge port 12e, respectively.
Even if the outside air introduction type circulating wind power sorter 12 is used as the wind power sorter as in the present embodiment, the effect of the present invention can be obtained in the same manner as in the above-described embodiment.
In addition, although FIG. 5 shows an example of one set of the cyclone type classifier 22 and the bug filter 16, as shown in FIG. 4, the cyclone type classifier 22B, the bug filter 16B, and the exhaust blower 18B are used. One set may be added to make a total of two sets.

(Embodiment 4)
An embodiment of a dry separation method and apparatus for volcanic ejecta sedimentary minerals of the present invention will be described with reference to FIG.
FIG. 6 is a schematic view showing an example of a dry separation device 5 used in the dry separation method of the present invention. In FIG. 6, the same members as those described above with reference to the drawings are designated by the same reference numerals, and duplicate description will be omitted below.

The dry type separator 5 of the present embodiment is different from the first and second embodiments in which the closed type circulating wind power sorter 11 is used in that the wind power sorter is a blow-up type wind power sorter 13 having a sirocco fan 13a. It is different.
Even if the blow-up type wind power sorter 13 is used as the wind power sorter as in the present embodiment, the effect of the present invention can be obtained in the same manner as in the above-described embodiment.

(Fine aggregate)
The specific gravity content obtained by the dry separation method of volcanic ejecta sedimentary minerals of the present invention has a density of 2.5 g / cm ³ or more and can be used for fine aggregates.
The difference in the specific gravity content obtained by the method of the present invention from the river sand and sea sand conventionally known as fine aggregates is that the heavy specific gravity content has no trace of aquatic organisms. It is the fine aggregate (sand) obtained by the present invention that has no traces of aquatic plants or plankton, microorganisms, shellfish, amphibians, crustaceans, fish eggs, scales, etc. of the indicator organisms, and the ecology of aquatic organisms and plants. It has the advantage of having a small environmental load without destroying the environment of the system. Shirasu is a type of mountain sand, but the pyroclastic flow deposits do not move with natural water, and have been orderly deposited on land for about 30,000 years before the occurrence of the Ito pyroclastic flow, and have been subjected to the elimination of water even once. There is an enormous amount of 75 billion cubic meters, undisturbed and undisturbed. On the other hand, Kagoshima's river sand and sea sand are eroded by rainfall and the action of river and coastal water on the Silas plateau, and the heavy mineral particles such as magnetite, feldspar, quartz, hornblende, and bright stone are removed from the silas. It is mainly deposited on the riverbed or seabed, and clay and fine powder have been washed away and diffused into the environment. Therefore, the origin of the eruption is the same, but the impact on the environmental load of the ecosystem is different. The difference is clear when biologically or botanically determined for the presence or absence of traces of such ecosystems.

In addition, conventionally known sea sand may contain a small amount of pumice stone and contains salt, whereas the fine aggregate (sand) obtained by the method of the present invention has a surface surface about 30,000 years ago. It is unsalted sand that does not contain salt, which is the weight specific gravity content obtained by dry separation of the pyroclastic flow deposits deposited in the sand, and the difference from sea sand is clear even with or without salt.
Furthermore, the difference from the conventionally known river sand is clear whether or not it is the "sand" of the present invention, depending on whether or not there are traces of freshwater organisms and freshwater plants.
Not only the fine aggregate obtained by the method of the present invention, but also pumice stone, volcanic glass, and fine powder can be discriminated by the same difference.

(Volcanic glass material)
Further, the residual volcanic glass material obtained by separating the fine aggregate by the dry separation method of the volcanic ejecta deposit mineral of the present invention is 0.3 mm by particle size by a specific gravity difference sorter, a cyclone type classifier and a dust collector. It can be separated into three types, exceeding 0.05 mm to 0.3 mm and less than 0.05 mm. Of these, those exceeding 0.3 mm can be used as lightweight aggregates, those of 0.05 mm to 0.3 mm can be used as pearlite (JIS A5007 equivalent) raw materials or shirasu balloon raw materials, or crushed and admixtures. If it is less than 0.05 mm, it can be used as an admixture or as an ultrafine admixture after further pulverization. An admixture made by further crushing a material having a thickness of 0.05 mm to 0.3 mm and an admixture material obtained by further crushing a material having a thickness of less than 0.05 mm have a more pozzolan effect. An apparatus for crushing volcanic glass materials having these particle sizes can be exemplified by a vibration mill. In addition to the vibration mill, various mills such as a roller mill, a JET mill, and a bead mill can also be used.
Among the volcanic glass materials, those with a particle size of less than 0.05 mm recovered by a bag filter for collecting fine powder have a density of 2.30 g / cm ³ or more and a loss on ignition of 3.5% or less. ..

Further, the above-mentioned admixture, that is, a material having a particle size of less than 0.05 mm obtained by separating the volcanic portland sediment mineral by a dry separation method according to the present invention, and a particle size of 0.05 mm to 0 obtained by separation. .3 mm crushed cement, obtained particle size less than 0.05 mm crushed further to make ultrafine cement, and mixed cement mixed with Portland cement are more seawater resistant and hot spring resistant than ordinary cement. It has excellent properties, chemical resistance, pulverization, long-term durability, and has a Pozzolan effect. The mixed cement is produced by crushing a mixture of volcanic glass material and Portland cement or cement clinker so that the two types of particles are uniformly mixed and dried, and further, mechanochemical reaction and fine powdering. Due to the effect of, the reactivity is increased and the mixed cement exhibits higher strength. For use in mixed cement, crushed volcanic glass material with a particle size of 0.05 mm to 0.3 mm, or crushed volcanic glass material with a particle size of less than 0.05 mm to make it ultrafine. The device can be exemplified by a vibration mill. In addition to the vibration mill, various mills such as a roller mill, a JET mill, and a bead mill can also be used. The above volcanic glass material can be used as a raw material for hydraulic lime and cement as well as a raw material for ceramics.

Residual volcanic glass material obtained by separating fine aggregates by the dry separation method of volcanic ejecta deposit minerals of the present invention, and the separated volcanic glass material with a particle size of 0.05 mm or more is used as it is or crushed. After that, it can be fired and expanded to obtain pearlite. The volcanic glass material having a particle size of 0.05 mm or more is the portion of the volcanic glass material excluding the fine powder having a particle size of 0.05 mm or less recovered by the bag filter 16. Specifically, the specific gravity difference sorting device 21 Pumice stones with a light specific gravity and fine particles for the underflow of the cyclone type classifier 22. By firing and foaming the pumice stone, it becomes a large-grain JIS A5007-equivalent pumice stone "Perlite", which is lighter than the lightweight aggregate.

The volcanic glass material having a particle size of 0.05 mm or more may be pulverized if necessary. Further, 0.105 mm or more and less than 0.105 mm may be sorted by a sorting means such as sieving so that pearlite can be obtained by using a material having a thickness of 0.105 mm or more as a raw material.

The separated volcanic glass material having a particle size of 0.05 mm or more is directly or crushed and then fired to expand it to obtain pearlite. The volcanic glass material expands and foams when fired in a flame or in a high temperature atmosphere, and the average particle size increases by about 1.5 times. For example, a 0.105 mm volcanic glass material expands by firing to a particle size of about 0.15 mm. The pearlite obtained by firing is a pearlite having a particle size specified in JIS A5007.
A static vertical furnace or a horizontal rotary furnace (rotary kiln) can be used for firing to obtain pearlite.

Of the residual volcanic glass material obtained by separating fine aggregates by the dry separation method of volcanic ejecta deposit minerals of the present invention, those having a particle size of 0.05 mm or more are directly or crushed and then fired and expanded. The obtained pearlite is a high-purity volcanic glass from which non-foaming heavy specific gravity crystalline materials (porcelain iron ore, feldspar, quartz, bright stone, keratinite, etc.) have been removed, resulting in wasteful crystalline material that becomes a defective product. Eliminating the loss of adding energy during firing, it is possible to efficiently use fossil fuel to produce lean pearlite. In addition, since the mixing of defective products is minimal, the quality of "Pearlite" products equivalent to JIS A5007 is improved. Further, as the firing furnace, for example, a static vertical furnace having a simple structure, a simple structure, and a low cost can be used, and high-purity volcanic glass is placed on the flame of the burner directly under the static vertical furnace. A pearlite equivalent to JIS A5007 can be manufactured by a simple method of directly pouring a material (0.105 mm or more or pumice stone). Furthermore, defective products such as heavy specific weight substances (crystal minerals) and unfoamed (small degree of foaming) volcanic glass raw materials contained in a small amount are separated by gravity under the direct flame burner of the firing furnace, so they are exhausted. The effect of combining with a vertical furnace that improves the quality of silasparlite products recovered by cyclone together with gas can be more exerted.

Next, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples.

(Example 1)
Using the apparatus and method of Embodiment 1 shown in FIG. 1, as the raw material volcanic ejecta deposit mineral, Kushira shirasu produced in Kushira-cho, Kanoya City, Kagoshima Prefecture, was dried indoors for one week ( A mixture (28.46 kg) having a water content of 0.3% (29.16 kg) sorted by a sieve 4a having an opening of 5 mm was used.

This ordinary shirasu was sorted into 14.80 kg of coarse particles having a particle size of 0.3 mm or more and 13.66 kg of non-coarse particles by a closed type circulating wind power sorter 11. The working conditions are that the supply speed of ordinary shirasu from which gravel has been removed is 56.9 kg / h, the rotation speed of the sirocco fan 11a of the circulating wind power sorter 11 is 142 rpm, the wind speed is 2.20 m / s, and the air volume is 9.76 m ³ / min. Met.

The coarse grain content was sorted into a specific gravity content, a light specific gravity content, and a dust collecting content by an air table type specific gravity difference sorting device 21. The working conditions are that the supply speed of coarse particles is 88.8 kg / h, the hole diameter of the perforated plate is 0.15 mm (100 mesh), the rotation speed of the eccentric crank that vibrates is 520 rpm, and the flow rate of the blower fan is 28 m ³ / min. The inclination of the perforated plate was set to 12.7 °. Further, the upper surface of the perforated plate 21a had irregularities with a wavy cross section.

The specific gravity component of the specific gravity difference sorting device 21 was discharged from the discharge port 21c, and 5.82 kg was recovered. The mass percentage of the weight specific gravity to 28.46 kg of ordinary shirasu before being put into the wind power sorter 11 was 20.5%. The specific gravity of the specific gravity was 2.66 g / cm ³ , and it could be used as a fine aggregate.

The light specific gravity component of the specific gravity difference sorting device 21 was discharged from the discharge port 21d, and 6.26 kg was recovered. The mass percentage of the light specific gravity to the ordinary shirasu before being put into the wind power sorter 11 was 22.0%. The light specific gravity was pumice with a particle size of 0.3 to 5 mm and a specific gravity of 1.90 g / cm ³ .

The dust collected by the specific gravity difference sorting device 21 was discharged from the discharge port 21e. The dust collector was classified by the cyclone type classifier 22 through the pipeline 7A, and then 13.06 kg of the underflow fine particles were collected. The specific gravity of the fine particles was 2.37 g / cm ³ . The mass percentage of fine particles to the ordinary shirasu before being put into the wind power sorter 11 was 45.9%.
Further, the overflow portion of the cyclone type classifier 22 was guided to the bag filter 16 via the pipeline 7I, and 0.57 kg of fine powder was recovered. The fine powder had a density of 2.37 g / cm ³ . The mass percentage of the fine powder with respect to the ordinary shirasu before being put into the wind power sorter 11 was 2.0%.
The residual amount on the perforated plate of the specific gravity difference sorting device 21 was 2.72 kg, and the unrecovered amount retained in the device was 0.03 kg.

Since the density is 2.5 g / cm ³ or more and the particle size distribution conforms to the JIS A5308 "sand" regulation, it can be used as a fine aggregate for concrete.
The light specific gravity is mainly composed of pumice with a particle size of 0.3 mm or more, and can be used as a natural lightweight aggregate. The volcanic glass material having a particle size of 0.3 mm or more and mainly composed of pumice stone can be used as a raw material for an admixture having a pozzolan effect or a mixed cement having a pozzolan effect when crushed.
The fine particles are mainly made of volcanic glass having a particle size of less than 0.3 mm and a particle size of 0.05 mm or more, and can be used as a pearlite raw material or a shirasu balloon raw material. When crushed, it can be used as an admixture having a pozzolan effect or as a mixed cement raw material having a pozzolan effect.
The fine powder is mainly made of volcanic glass with a particle size of less than 0.05 mm, and can be made into an admixture or an admixture with a better pozzolan effect by crushing, and a mixed cement obtained by mixing the crushed material with Portland cement. Can be used as a raw material. The volcanic glass material can be used as a raw material for hydraulic lime and cement as well as a raw material for ceramics.

A feature of the present invention is that undried or dried raw materials in which fine particles having different specific gravities and coarse particles are mixed and difficult to separate by specific gravity can be selected by specific gravity at low cost, and pyroclastic flow deposits such as ordinary pumice and Kanuma soil, etc. In addition to abundant and widely distributed volcanic ejecta sedimentary minerals such as pumice fall such as Kaya soil, natural selection of volcanic ejecta such as Kakuto silas and Yoshida silas, crushed stones, sand and soil Of course, dry specific gravity separation of natural and man-made crushed products and aggregates such as pearl rock, pumice rock, pine fat rock, and limestone, and industrial waste such as construction waste and concrete waste is possible.
In addition, it separates raw materials with a heavy specific gravity such as unfoamed volcanic glass or fluffy stone contained in artificial fired foams such as pearlite, silas balloons, and vermiculite, heat media such as ceramics, and foreign substances such as rust, and has a light specific gravity. It is possible to purify high-value-added calcined foam.

1, 2, 3, 4, 5 Dry separator 3a, 5a, 6 Belt feeder 4a, Sieve 7A, 7I Pipeline 11, 12 Wind power sorter 11a, 13a Sirocco fan 21b Blower fan 11b Sorting column 11c Diffusion chamber 11d, 12d Raw material supply port 11e, 11f, 12e, 21c, 21d, 21e Discharge port 12g Rocker valve 13 Blow-up wind power sorter 16, 16A, 16B Bug filter 16b, 22b On-off valve 17, 17I Pipeline 17a Flow control valve 18, 18A, 18B Exhaust blower 21 Specific gravity difference sorting device 21a Perforated plate 21g Vibration device 21h Wind cylinder 22, 22A, 22B Cyclone type classifier J Exhaust

Claims (14)

The remainder of the volcanic ejecta sedimentary minerals from which gravel has been removed is supplied to at least one type of wind power sorter selected from a circulation type wind power sorter and a blow-up type wind power sorter to separate coarse particles and non-coarse particles. Divide into two
The coarse particles are supplied from the upper end of the perforated plate to an air table type specific gravity difference sorting device that blows air from below toward the perforated plate while vibrating the perforated plate inclined at a predetermined angle from the horizontal direction. A dry separation method for volcanic ejecta sedimentary minerals, which comprises collecting the selected material as fine aggregate. The dry separation method for volcanic ejecta sedimentary minerals according to claim 1, wherein pumice stones are collected from the lower end of the perforated plate. The dry separation method for volcanic ejecta sedimentary minerals according to claim 1 or 2, wherein the material blown up from the perforated plate is further sorted into fine particles and fine powder by a cyclone type classifier. The dry separation method for volcanic ejecta deposit minerals according to any one of claims 1 to 3, wherein the perforated plate has a mesh size of 0.1 to 0.25 mm. The dry separation method for volcanic ejecta sedimentary minerals according to any one of claims 1 to 4, wherein the coarse particles other than the coarse particles are further sorted into fine particles and fine powder by a cyclone type classifier. At least one type of wind power sorter selected from circulation type wind power sorters and blow-up type wind power sorters that supplies the balance after removing gravel from volcanic ejecta sedimentary minerals and sorts them into coarse and non-coarse particles. ,
An air table to which coarse particles sorted by the circulation type wind power sorter or a blow-up type wind power sorter are supplied, and air is blown from below toward the perforated plate while vibrating a perforated plate inclined at a predetermined angle from the horizontal direction. Equipped with a specific gravity difference sorting device of the formula,
A dry separation device for volcanic ejecta deposit minerals, wherein the specific gravity difference sorting device sorts fine aggregates from the upper end of the perforated plate. The dry separation device for volcanic ejecta deposit minerals according to claim 6, wherein the specific gravity difference sorting device sorts pumice stones from the lower end of the perforated plate. The dry separation device for volcanic ejecta deposit minerals according to claim 6 or 7, further comprising a cyclone type classifier that sorts what is blown up from the perforated plate into fine particles and fine powder. The dry separation device for volcanic ejecta sedimentary minerals according to any one of claims 6 to 8, wherein the perforated plate has a mesh size of 0.1 to 0.25 mm. The dry separation device for volcanic ejecta sedimentary minerals according to any one of claims 6 to 9, further comprising a cyclone type classifier for sorting fine particles and fine powders other than the coarse particles. A method for producing a fine aggregate, which comprises obtaining a fine aggregate by the dry separation method for volcanic ejecta sedimentary minerals according to any one of claims 1 to 5. A method for producing pumice, which comprises obtaining pumice by the dry separation method for volcanic ejecta sedimentary minerals according to any one of claims 2 to 5. A method for producing a fine-grained volcanic glass material, which comprises obtaining a fine-grained volcanic glass material by the dry separation method for volcanic ejecta sedimentary minerals according to any one of claims 3 to 5. A method for producing a finely powdered volcanic glass material, which comprises obtaining a finely powdered volcanic glass material by the dry separation method for volcanic ejecta sedimentary minerals according to any one of claims 3 to 5.

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