JP6912696B2 - Hydraulic lime and its manufacturing method - Google Patents

Description

The present invention relates to hydraulic lime made from volcanic ejecta sedimentary minerals such as ordinary shirasu and a method for producing the same.

Hydraulic lime is lime that hardens when mixed with water, and because it is hydraulic, it has higher strength than hydraulic slaked lime, and it returns to limestone over time due to carbonation in the air. High durability performance can be obtained. Hydraulic lime is obtained as natural hydraulic lime, but the production area of hydraulic lime is limited, and the availability is not sufficient as imported products from overseas are used in Japan. There are also variations in quality.

There is a method of producing hydraulic lime from limestone washing wastewater generated in the limestone production process as a raw material (Patent Document 1). However, the method described in Patent Document 1 is a technique for recycling limestone washing wastewater, and is not suitable for mass production of hydraulic lime.
There is a hydraulic lime composition containing a synthetic silicon compound prepared by precipitation or gelation or a synthetic silicon compound prepared by subjecting natural silicon to a chemical treatment, heat treatment, or other physical treatment as a pozzolan material (patented). Document 2). However, the hydraulic lime composition described in Patent Document 2 is unsuitable for mass production because the pozzolan material is costly because it chemically treats natural silicon, heat-treats it, or otherwise physically treats it.

Japanese Unexamined Patent Publication No. 2007-204282 Patent No. 5678716

By the way, Silas is one of the volcanic ejecta sedimentary minerals widely distributed in South Kyushu and is a resource that can be obtained in large quantities. Therefore, if hydraulic lime can be obtained from Silas, it can be used instead of natural hydraulic lime. It can also be a hydraulic lime of better quality than natural hydraulic lime.

However, ordinary shirasu, that is, shirasu that forms the shirasu plateau in Southern Kyushu and is not processed in its natural state, has a wide particle size distribution from coarse to fine powder, and is therefore hydraulic. To use it as a raw material for lime, a crushing process is required, and crushing requires a lot of labor. In addition, since Shirasu usually contains a large amount of hard crystalline minerals, the crusher wears a lot during crushing, and the crystalline minerals are mixed in the crushed product, which causes deterioration of the quality of hydraulic lime.

An object of the present invention is to provide hydraulic lime made from volcanic ejecta sedimentary minerals and an advantageous method for producing the same.

The present inventors use volcanic ejecta sedimentary minerals, for example, fine powder of volcanic glass separated from ordinary silas as one of the raw materials, and calcining this and lime at 900 to 1150 ° C. free CaO and belite. , Wallastonite and Gerenite, found that hydraulic lime containing at least one selected from them can be obtained, and based on this finding, the present invention has been made.

One aspect of the present invention is hydraulic lime, which is made from lime and fine powder of volcanic glass material separated from volcanic ejecta sedimentary minerals and contains at least one selected from free CaO, belite, wallastonite and guerenite. It is lime.

In the above invention, the volcanic ejecta sedimentary mineral can be usually Shirasu.

Another aspect of the present invention is a method for producing hydraulic lime, which comprises using lime and fine powder of volcanic glass material separated from volcanic ejecta sedimentary minerals as raw materials and firing at 900 to 1150 ° C.

In the above invention, it is preferable that the volcanic ejecta deposit mineral is usually shirasu.

One method of separating fine powder of volcanic glass material separated from volcanic ejecta sedimentary minerals is to remove gravel having a particle size of more than 5 mm from the volcanic ejecta depositary minerals and transport the rest to a normal temperature or high temperature air flow. A cyclone classifier group for coarse particle recovery having at least two cyclone classifiers connected to a circulating air flow path, a cyclone classifier for fine particle recovery connected to this cyclone classifier group, and this cyclone classifier. By the airflow classification device having a dust collector for collecting fine powder connected to, coarse particles are obtained by the cyclone classifier group for collecting coarse particles, fine particles are obtained by the cyclone classifier for collecting fine particles, and fine powder is obtained by the dust collector for collecting fine particles. Is to be recovered, and the recovered fine powder is used as the raw material.

Another method of separating fine powder of volcanic glass material separated from volcanic ejecta deposit minerals is to remove gravel having a particle size of more than 5 mm from the volcanic ejecta deposit mineral and tilt the rest at a predetermined angle from the horizontal direction. The perforated plate is vibrated and supplied to an air table type specific gravity difference sorter that blows air from below toward the perforated plate, and the weight specific gravity, the light specific gravity, the dust collection, and the perforated plate drop are The selected dust collection material is used as the raw material.

Another method of separating the fine powder of the volcanic glass material separated from the volcanic ejecta sedimentary mineral is to remove the gravel having a particle size of more than 5 mm from the volcanic ejecta sedimentary mineral and transport the rest to a normal temperature or high temperature airflow. , A cyclone classifier group for coarse particle recovery having at least two cyclone classifiers connected to a circulating air flow path, a cyclone classifier for fine particle recovery connected to this cyclone classifier group, and this cyclone classifier. By the airflow classifying device having a dust collector for collecting fine powder connected to the machine, coarse particles are collected by the cyclone classifying machine group for collecting coarse particles, fine particles are collected by the cyclone classifying machine for collecting fine particles, and fine particles are collected. Collect the fine powder with a dust collector and
The collected coarse particles are supplied to an air table type specific gravity difference sorter that blows air from below toward the perforated plate while vibrating a perforated plate that is tilted at a predetermined angle from the horizontal direction. Sort by specific density, dust collection, and perforated plate drop,
The fine powder and the dust collector are used as the raw materials.

When the above-mentioned cyclone classifying machine group is used, one of the cyclone classifying machines for collecting coarse particles has a conical shape at the upper part and is connected to the pipeline at the top of the conical shape. It is preferable that the particle size of the fine powder is less than 0.05 mm. Further, the classified coarse particles can be crushed into fine powder.

When the above-mentioned air table type specific gravity difference sorting device is used, the amount of the perforated plate dropped by the air table type specific gravity difference sorting device is transferred to the same or different air table type specific gravity difference sorting device under different working conditions. Supply and further sort into at least the heavy specific density, the light specific density, and the dust collector,
Further, it is preferable to use the selected dust collector as the raw material.
In the case of further sorting as described above, it is preferable to sort into a heavy specific density component, a light specific gravity component, a dust collecting component, and a perforated plate falling component. Further, when the first-stage air table type specific gravity difference sorting device and the second-stage air table type specific gravity difference sorting device are used in combination, the light specific density component in the first-stage air table type specific gravity difference sorting device may be used. The dust collection can be supplied to the second-stage air table type specific gravity difference sorting device. Further, it is preferable that the particle size of the dust collected is less than 0.05 mm. Further, the light specific density component can be further crushed into fine powder.

The hydraulic lime of the present invention can be used as a raw material for producing mortar, and the method for producing hydraulic lime of the present invention can be used for the method for producing mortar.

According to the present invention, it is possible to obtain hydraulic lime and a method for producing the same, using a volcanic glass material separated from volcanic ejecta sedimentary minerals as a raw material.

It is the schematic of an example of the dry type separation apparatus suitable for use in the manufacturing method of hydraulic lime of this invention. It is a schematic diagram which shows an example of the dry type separation apparatus suitable for use in the manufacturing method of hydraulic lime of this invention. This is a modification of FIG. It is a modification of FIG. This is an example of a combination of the modified example of FIG. 3 and the modified example of FIG. It is the schematic which shows an example of the dry type separation apparatus suitable for use in the manufacturing method of hydraulic lime of this invention. It is a schematic diagram explaining the principle of the specific density difference sorting apparatus. It is a modification of FIG. It is the schematic which shows an example of the dry type separation apparatus suitable for use in the manufacturing method of hydraulic lime of this invention. It is a modification of FIG. It is the schematic which shows an example of the dry type separation apparatus suitable for use in the manufacturing method of hydraulic lime of this invention. It is the schematic which shows an example of the dry type separation apparatus suitable for use in the manufacturing method of hydraulic lime of this invention. It is the schematic which shows an example of the dry type separation apparatus suitable for use in the manufacturing method of hydraulic lime of this invention. It is an X-ray diffraction pattern of Example 4. FIG. It is an X-ray diffraction pattern of calcined lime which heated only Tokunoshima limestone of Comparative Example 9 at 1000 degreeC.

Hereinafter, embodiments of the hydraulic lime and the method for producing hydraulic lime of the present invention will be described with reference to the drawings, using an example using ordinary silas, which is a kind of volcanic ejecta sedimentary mineral, as a raw material.

(Embodiment 1)
In this embodiment, fine powder of volcanic glass material is separated from ordinary Shirasu. An embodiment of a dry separation method and an apparatus for separation 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 applied to the present invention.
The dry separation device shown in FIG. 1 includes an air flow classification device 10. The airflow classifying device 10 has a cyclone classifying machine group 12 to 14 for coarse grain recovery, a cyclone classifying machine 15 for fine grain recovery, and a bug filter 16 for fine powder recovery connected to the cyclone classifying machine. There is.

In the illustrated dry separator, normal shirasu is supplied from the belt feeder 3 to the sieve 4, and the sieve 4 removes gravel having a particle size of more than 5 mm as an upper sieve, and the balance is as a lower sieve to the air flow classifier 10. Be supplied. In the illustrated example, a sieve 4 is used to remove gravel having a particle size of more than 5 mm, but instead of the sieve 4, a machine for crushing the particle size of the raw material, ordinary shirasu, to 5 mm or less may be used. 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. 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. be.

The airflow classification device 10 includes a plurality of cyclone crushers 11A, 11B, 11C, a plurality of cyclone classifiers 12 to 15, a bug filter 16, and pipelines 17A to 17I connecting them.

In the airflow classifying device 10, a normal silas having a particle size of 5 mm or less, which has been classified under a sieve, is first guided to a cyclone crusher 11A, and then guided from the cyclone crusher 11A to a cyclone crusher 11B via a pipe line 17A to solve the cyclone. It is guided from the crusher 11B to the cyclone crusher 11C via the conduit 17B. At the inlet of the cyclone crusher 11A, the suction force to the pipelines 17A to 17I caused by the exhaust blower 18 works, and a large amount of intake air G is drawn from the inlet of the square pipe installed on the outermost circumference of the cyclone crusher 11A. It is introduced and becomes a spiral swirling flow in the downward direction, and when the silas raw material is dropped with a small amount of intake air from above, the agglomerates are dispersed by the spiral downward flow of air flow and the inner wall of the pipe is laid. It is sent to the next cyclone crusher 11B by tracing, and it is possible to smoothly input a large amount of raw materials without clogging. The main energy required for transporting, drying, single-particle formation, and separation of raw materials is powered by the suction force of the exhaust blower 18, and the cyclone crusher and cyclone classifier are combined three-dimensionally to create a compact yet straight path. It has a structure that maximizes the moving distance of the raw material particles beyond the distance, and by increasing the contact between the raw material and the air, airflow drying and single particle formation of the particles can be efficiently exhibited.

The cyclone crushers 11A to 11C are cyclones for usually dispersing the agglomeration of Shirasu grains by centrifugal force. The ordinary shirasu dispersed through the cyclone crushers 11A to 11C is guided to the cyclone classifier 12 via the conduit 17C. In the cyclone crusher passing through 11A to 11C and in the pipeline connecting them, collision, friction, contact of adhered particles and agglomerated particles with the inner wall surface of the cyclone crusher and the inner wall of the conduit, and collision, friction, and contact between these particles occur. It works forcibly to promote the separation of fine particles and fine powder attached to coarse particles, dissociation and crushing of aggregates, and the moisture attached to the particles and the moisture intervening between the particles enter the air by contact with air. It moves and the particles dry out. Therefore, when the raw material, ordinary shirasu, contains approximately 4% or more of water, the dry separator of the present embodiment having cyclone crushers 11A to 11C and drying with cyclone crushers 11A to 11C should be used. Is preferable.

The synergistic effect of peeling, crushing, and drying by the cyclone crushers 11A to 11C promotes the single particle formation of coarse particles, fine particles, and fine particles. The cyclone classifier 12 connected to the cyclone crusher 11C classifies ordinary shirasu into coarse grains and non-coarse grains. In order to promote the single particleization of coarse particles, fine particles, and fine particles, a total of four, five, or more cyclone crushers may be provided as shown in FIGS. 3 and 5.

The upper part of the cyclone classifier 12 has a conical shape, and the top of the conical shape is connected to the conduit 17D. Since the upper part of the cyclone classifier 12 has a conical shape, the flow of the swirling airflow rising upward from the cyclone classifier 12 is smoothed, and coarse particles having a predetermined particle size are placed below the cyclone classifier 12. Those having a particle size smaller than the coarse particles are dropped and transported to the pipeline 17D by the airflow rising upward from the cyclone classifier 12.
The conduit connected below the cyclone classifier 12 is provided with an opening 12a. The opening 12a is an intake air adjusting means, and by adjusting the size of the opening 12a, the flow velocity of the updraft in the pipeline provided with the opening 12a can be adjusted. More specifically, by enlarging the opening 12a to increase the flow velocity of the updraft from the lower side to the upper side of the cyclone classifier 12, ^{the proportion of coarse particles having a density of 2.5 g / cm 3} or more is improved. be able to. The opening 12a is, for example, a gap between flange joints. By adjusting the gap between the gaps with washers or the like having different thicknesses, the amount of air of the intake air taken in from the opening 12a can be adjusted, and the cyclone classifier 12 can be used. The flow velocity of the updraft from the bottom to the top can be adjusted.
The pipeline connected below the cyclone classifier 12 has two on-off valves 12b below the opening 12a. During the operation of the illustrated dry separator, coarse particles are deposited in a conduit connected below the cyclone classifier 12. In order to collect the coarse grains during work, the upper on-off valve 12b is first opened and the lower on-off valve 12b is closed, whereby the coarse grains are placed between the upper on-off valve 12b and the lower on-off valve 12b. Then, the upper on-off valve 12b is closed and the lower on-off valve 12b is opened, whereby coarse particles between the upper on-off valve 12b and the lower on-off valve 12b are collected. Here, a rotary valve having the same function can be used instead of the on-off valve 12b.

In order to increase the yield of coarse particles made into single particles, a cyclone classifier 13, a pipeline 17D, and a pipeline 17E are provided, and the overflow portion of the cyclone classifier 12 is transferred to the cyclone classifier 13 via the pipeline 17D. It forms the first circulation path that guides and guides the underflow component of the cyclone classifying machine 13 to the cyclone classifying machine 12 via the pipe line 17E connected to the pipe line 17C. Further, in order to further increase the yield of the coarse particles that have been made into single particles, a cyclone classifier 14, a pipeline 17F, and a pipeline 17G are provided, and the overflow portion of the cyclone classifier 13 is classified into a cyclone via the pipeline 17F. A second circulation path is formed which guides the cyclone classifier 14 to the machine 14 and guides the underflow component of the cyclone classifier 14 to the cyclone classifier 13 via the conduit 17G connected to the conduit 17D. By circulating in the circulation path of these air streams, collisions, frictions, and contacts of adhered particles and agglomerated particles with the inner wall surface of the cyclone classifier and the inner wall of the pipeline are forced to work. The exfoliation of fine particles and fine particles adhering to the coarse particles and the crushing of the agglomerates are promoted, and the moisture adhering to the particles and the moisture intervening between the particles move to the air by contact with the air, and the particles are dried. move on. The synergistic effect of these peeling, crushing, and drying promotes the single particle formation of coarse particles, fine particles, and fine particles. Due to the above effects, even if the air flow in the pipeline and the cyclone classifier is at room temperature, the moisture content of Shirasu is usually reduced and the shirasu is dried. If the intake G introduced into the cyclone crusher 11A is dry air or warm air, the drying and single particle formation of Shirasu will be further promoted.

In the present embodiment shown in FIG. 1, a cyclone classifying machine 13 and a cyclone classifying machine 14 are provided in order to form two circulation paths, but three, four or more circulation paths are formed. Therefore, as shown in FIGS. 4 and 5, a total of three, four, or more cyclone classifiers may be provided.

The overflow portion of the cyclone classifying machine 14 is guided to the cyclone classifying machine 15 via the conduit 17H. The cyclone classifying machine 15 classifies the overflow portion of the cyclone classifying machine 14 into fine particles and fine powders other than fine particles. The fine particles have a particle size of 0.05 to 0.30 mm and are supplied to a sieve described later. The value of the particle size of the fine particles classified by the cyclone classifier 15 of 0.05 to 0.30 mm is an approximate value. Further, the value of the particle size or the recovery rate of the fine particles can be adjusted by adjusting the size of the opening 15a provided in the lower pipeline of the cyclone classifier 15 as the intake air adjusting means.

The conduit connected below the cyclone classifier 15 is provided with an opening 15a. The opening 15a is an intake air adjusting means, and by adjusting the size of the opening 15a, the flow velocity of the updraft in the pipeline provided with the opening 15a can be adjusted, and thus the particle size distribution or the average particle size of the fine particles can be adjusted. Alternatively, the recovery rate can be adjusted. The opening 15a is, for example, a gap of a flange joint. By adjusting the gap between the gaps with washers or the like having different thicknesses, the amount of air of the intake air I taken in from the opening 15a can be adjusted, and the air amount of the intake air I taken in from the opening 15a can be adjusted from below the cyclone classifier 15. The flow velocity of the upward airflow can be adjusted.

The pipeline connected below the cyclone classifier 15 has two on-off valves 15b below the opening 15a. During the operation of the illustrated dry separator, the granules deposit in the conduit connecting below the cyclone classifier 15. In order to collect the fine particles during work, the upper on-off valve 15b is first opened and the lower on-off valve 15b is closed, whereby the fine particles are placed between the upper on-off valve 15b and the lower on-off valve 15b. Then, the upper on-off valve 15b is closed and the lower on-off valve 15b is opened, whereby fine particles between the upper on-off valve 15b and the lower on-off valve 15b are collected. Here, a rotary valve having the same function can be used instead of the on-off valve 15b.

The collected fine particles are sieved by a sieve 19. The mesh of the sieve is 300 μm, and fine particles having a particle size of more than 0.3 mm are separated on the sieve, and fine particles having a particle size of 0.3 mm or less are separated under the sieve. The fine particles classified as the underflow component of the cyclone classifier 15 are mainly volcanic glass and contain 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. Therefore, the lightweight aggregate can be recovered by sieving with a sieve 19 having a particle size of 0.3 mm.

Further, the bottom of the sieve 19 is a volcanic glass material having a particle size of less than 0.3 mm. In particular, when the volcanic ejecta sedimentary 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, by crushing a volcanic glass material having a particle size of less than 0.3 mm, it can be used as a raw material or an admixture for the hydraulic lime of the present invention. In the dry separation method of the present embodiment, since fine powder having a particle size of 0.05 mm or less is classified as an overflow component of the cyclone classifier 15, the sieve 19 contains almost no fine powder. Therefore, it is possible to obtain a volcanic glass material B2 having a uniform particle size with a particle size of approximately 0.05 mm to 0.3 mm under the sieve of the sieve 19.

As the overflow portion of the cyclone classifier 15, fine powders other than fine particles are guided to the bug filter 16 via the conduit 17I. The bug filter 16 collects the fine powder C. The fine powder C has a particle size of 0.05 mm or less. The value of the particle size of the fine powder C of 0.05 mm or less is an approximate value. The fine powder C is mainly made of volcanic glass and is useful as a raw material for hydraulic lime of the present invention, a mixed cement raw material having a pozzolan effect, and 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 exhaust blower 18 is connected to the bag filter 16, and the exhaust J is discharged from the airflow passing through the filter cloth of the bag filter 16 by the exhaust blower 18. Further, the cyclone crushers 11A, 11B, 11C and the cyclone classifiers 12 to 15 are driven by the exhaust blower 18, and the conveyed airflow is discharged to the outside from the exhaust blower 18.
According to the dry separation method and the dry separation device of the present embodiment shown in FIG. 1, ordinary shirasu can be separated into coarse particles A, fine particles B, and fine powder C, and fine particles B have a particle size of 0. It can be separated into a particle size of more than 3 mm (B1) and a particle size of 0.3 mm or less (B2). Of these, pulverized fine powder C or fine B2 is used as a raw material for the hydraulic lime of the present invention. Further, according to the dry separation method and the dry separation apparatus of the present embodiment, no crushing step is required, and even when crushed, it contains almost no hard crystalline minerals, so that the crusher is less worn during crushing and crystals become impurities. Since it contains almost no minerals, hydraulic lime with a high volcanic glass content can be obtained.

(Embodiment 2)
Another embodiment of the dry separation method and apparatus applied to the present invention will be described.
FIG. 2 is a schematic view showing an example of a dry separation device suitable for use in the dry separation method applied to the present invention. In FIG. 2, the same members as those in FIG. 1 are designated by the same reference numerals. Therefore, in the present embodiment, the duplicate description of the same member as described above in the first embodiment will be omitted. Further, instead of the illustrated sieve 4, a machine for pulverizing the particle size of ordinary shirasu, which is a raw material, to 5 mm or less can also be used.

The difference between the dry separator shown in FIG. 2 and the dry separator shown in FIG. 1 is that it has a rotary feeder 20 that normally supplies shirasu to cyclone classifiers 12 to 14 for collecting coarse particles. Is. When the water content of the raw material, ordinary shirasu, is approximately less than 4%, it circulates smoothly in the cyclone classifiers 12 to 14 for coarse grain recovery without drying via the cyclone crushers 11A to 11C. It can be dried in the process of circulating in the cyclone classifier groups 12 to 14 for collecting coarse particles. Therefore, the normal shirasu is supplied to the top of the cyclone classifier 13 by the rotary feeder 20 that can be supplied quantitatively.

The rotary feeder 20 has a high degree of airtightness, and can quantitatively supply the shirasu raw material without the need for air transportation. The ordinary shirasu introduced from the rotary feeder 20 to the upper part of the cyclone classifying machine 13 is sent to the cyclone classifying machine 14 from the pipeline 17F on the air flow. The fine powder that has been made into single particles by centrifugation with the cyclone classifier 14 is conveyed to the upper pipeline 17H as an overflow component. The fine particles and fine particles cannot be completely separated, and the coarse particles and agglomerates to which they adhere are centrifuged by the cyclone classifier 13 through the conduit 17D together with the crushed single particles. In the cyclone classifier 13, the coarse particles that have fallen downward come into contact with the airflow introduced from the intake port of the cyclone crusher 11A and flowing through the cyclone crushers 11A to 11C, pass through the conduit 17C, and pass through the cyclone classifier 11C. Sent to 12. After that, as described in the first embodiment, the fine aggregate is separated from the cyclone classifier 12 by repeating the crushing and separation of the normal shirasu in the pipeline by the circulation path system of the cyclone classifier.

The supply of ordinary shirasu is not limited to the rotary feeder 20 when the water content of the raw material ordinary shirasu is approximately less than 4%. A part or all of ordinary shirasu can also be passed through the cyclone crusher groups 11A to 11C. Further, when the water content of the raw material ordinary shirasu is approximately 4% or more, the ordinary shirasu is not limited to passing through the cyclone classifier groups 12 to 14. A part of ordinary Shirasu can also be supplied from the rotary feeder 20.

According to the dry separation method and the dry separation device of the present embodiment shown in FIG. 2, as in the dry separation method and the dry separation device of the first embodiment shown in FIG. 1, ordinary shirasu is divided into coarse particles, fine particles, and fine powder. The fine particles can be further separated into those having a particle size of more than 0.3 mm and those having a particle size of 0.3 mm or less. Of these, crushed fine powder C or fine B2 is used as a raw material for hydraulic lime. According to the dry separation method and the dry separation device of the present embodiment, no crushing step is required, and even when crushed, it contains almost no hard crystalline minerals, so that the crusher is less worn during crushing, and crystalline minerals that become impurities can be obtained. Since it contains almost no volcanic glass, hydrohard lime having a high volcanic glass component ratio can be obtained.

FIG. 3 is a modification of FIG. 1, which is an example in which the cyclone crusher has a total of five cyclone crushers 11A, 11B, 11C, 11D and 11E. As can be seen from FIGS. 1 and 3, the number of cyclone crushers does not matter in the dry separator suitable for use in the method for producing hydraulic lime of the present invention.

FIG. 4 is a modification of FIG. 2, which is an example in which the cyclone classifier has a total of five cyclone classifiers 12, 13, 14, 31 and 32. As can be seen from FIGS. 2 and 4, in the dry separator suitable for use in the method for producing hydraulic lime of the present invention, the number of cyclone classifiers may be two or more.

FIG. 5 is an example of a combination of the modified example of FIG. 3 and the modified example of FIG. 4, and has a total of five cyclone crushers 11A, 11B, 11C, 11D and 11E, and classifies the cyclone. This is an example of having a total of five cyclone classifiers 12, 13, 14, 31 and 32.

(Embodiment 3)
An embodiment of a dry separation method for volcanic ejecta sedimentary minerals applied to the present invention will be described.
FIG. 6 is a schematic view showing an example of a dry separation device suitable for use in the method for producing hydraulic lime 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 separation device shown in FIG. 6 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. Further, the upper surface of the perforated plate 21a has a saw blade-shaped unevenness in cross section, and the height difference of the unevenness is about 3 to 20 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 so that it 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. It is possible to apply a force that pushes the weight specific gravity caught in the saw blade-shaped recess upward. 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. Although the blower fan 21b is of a built-in wind cylinder type, it may be an external blower fan having an ability to introduce air into the wind cylinder. When a mixture of a plurality of specific gravity powders is supplied to the upper surface of the perforated plate 21a, the vibrating device 21g is caught by the heavy powder having a specific specific density (indicated by the black circle in FIG. 7) and the saw blade-like unevenness on the upper surface of the perforated plate 21a. Due to the vibration of the perforated plate 21a due to the above, the perforated plate 21a moves toward the upper side. The powder having a light specific density is blown up by the air flow through the pores of the perforated plate 21a. Among the powders with a light specific density that have risen up, the powders with a relatively heavy specific density (indicated by white circles in FIG. 7) move toward the lower side of the perforated plate 21a. Among the powders having a relatively light specific density, the powders having a relatively light specific density (indicated by black dots in FIG. 7) are conveyed to the outside of the specific gravity difference sorting device 21 by the air flow.

Therefore, by supplying ordinary shirasu to the specific gravity difference sorting device 21 and blowing air from below toward the porous plate 21a while vibrating the porous plate 21a, the heavy specific gravity content is applied to the upper side of the porous plate 21a and the lower side. Light specific density can be selected. Further, among the ordinary shirasu supplied to the perforated plate 21a, those having a small particle size (hereinafter referred to as “dust collector”) float from the perforated plate 21a by blowing air. Further, a part of the ordinary shirasu supplied to the perforated plate 21a falls through the holes of the perforated plate 21a.

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 weight specific gravity content.} 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 performed by adjusting at least one of the frequency of 21a, the amount of sucked air related to the exhaust port 21e, and the like.

The weight 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 weight specific gravity content has a density of 2.5 g / cm ³ or more. ^{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 portion of the perforated plate dropped by the perforated plate 21a is discharged from the discharge port 21f and collected. The recovered perforated plate can have a ^{density of 2.5 g / cm 3} or more depending on the raw material and working conditions. This perforated plate drop can be used as it is as a fine aggregate when ^{the density of 2.5 g / cm 3} or more specified by "sand" of JIS A5308 is satisfied.

When the drop amount of the perforated plate selected by the perforated plate 21a is 2.5 g / cm ³ or less, it cannot be used as a fine aggregate defined by "sand" of JIS A5308. In this case, as will be described later, the amount of the perforated plate dropped can be further separated by a specific gravity difference sorting device (see FIGS. 9 and 10).

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 component is applied to a sieve 23, which will be described later, via the belt conveyor 6 and the belt feeder 9.

The dust collected from the perforated plate 21a is guided to the cyclone classifier 22 via the conduit 7A connected to the discharge port 21e of the specific gravity difference sorting device 21. The cyclone classifier 22 classifies lighter fine powder as an overflow component from the dust collector. The cyclone recovered from the underflow is recovered as a raw material for a shirasu balloon or a raw material for an admixture. The cyclone recovered portion of the underflow portion can also be crushed and used as a raw material for the hydraulic lime of the present invention. Further, the overflow fine powder of the cyclone classifier 22 is guided to the bag filter 16 through the pipeline 7I and collected. The recovered fine powder F is used as a raw material for hydraulic lime. The bug filter 16 has already been described.

The sieve 23 has a predetermined mesh size. The mesh size of the sieve 23 can be, for example, 300 μm. The light specific gravity component of the specific gravity difference sorting device 21 is guided to the sieve 23 and divided into an upper sieve and a lower sieve.

The light specific gravity component of the specific gravity difference sorting device 21 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. Therefore, the lightweight aggregate can be recovered by sieving with a sieve 23 having a particle size of 0.3 mm.

Further, below the sieve of the sieve 23 is a volcanic glass material having a particle size of less than 0.3 mm. In particular, when the volcanic ejecta sedimentary 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, by crushing a volcanic glass material having a particle size of less than 0.3 mm, it can be used as a raw material or an admixture for the hydraulic lime of the present invention. In the dry separation method of the present embodiment, since the fine powder having a particle size of 0.05 mm or less is classified in advance by the specific gravity difference sorting device 21, the sieve 23 contains almost no fine powder. Therefore, a shirasu balloon raw material having good foamability can be obtained under the sieve of the sieve 23.

In utilizing the volcanic glass having a particle size of less than 0.3 mm in the light specific gravity of the specific gravity difference sorting device 21, it is not always necessary to sift through the sieve 23. FIG. 8 is a modification of FIG. The dry separator shown in FIG. 8 does not have a sieve 23.
As shown in FIG. 8, the light specific gravity component does not need to be sieved by the sieve 23 with a particle size of 0.3 mm, but the sieve 23 is omitted if it conforms to the JIS A5002 “Structural Lightweight Concrete Aggregate” standard. Therefore, the lightweight aggregate can be recovered in a simplified manner.

According to the dry separation method and apparatus of the present embodiment shown in FIGS. 6 and 8, ordinary shirasu is separated into a heavy specific density D, a light specific density E, and a fine powder F by using a specific gravity difference sorting device 21 or 21D. Further, the light specific density component can be further separated by a sieve 23 into, for example, a particle size of more than 0.3 mm (E1) and a particle size of 0.3 mm or less (E2). This fine powder F is used as a raw material for hydraulic lime. E2 can also be crushed into a raw material for hydraulic lime. Further, according to the dry separation method and the dry separation apparatus of the present embodiment, no crushing step is required, and even when crushed, it contains almost no hard crystalline minerals, so that the crusher is less worn during crushing and crystals become impurities. Since it contains almost no minerals, hydraulic lime with a high volcanic glass content can be obtained. Further, since the fine aggregate having a density of 2.5 g / cm ³ or more is contained in the weight specific gravity content D, the fine aggregate having a ^{density of 2.5 g / cm 3 or more can be obtained by recovering the weight specific gravity content D.} The yield can be increased.
Since the dry separation method and the dry separation device of the present embodiment do not have the cyclone crusher or the cyclone classifier used in the dry separation method of the first embodiment or the second embodiment, the raw material by the cyclone crusher or the cyclone classifier is not provided. You can't expect much dryness. However, before separating the gravel with the sieving 4, the raw material is spread a few centimeters indoors in the sunlight without spending a great deal of cost by forced drying with a dryer to reduce the moisture content to less than about 2%. The raw material is dried to some extent by another economical drying method, such as leaving it for several days or more, turning it upside down at regular intervals, and reducing the moisture content of the raw material, ordinary gravel, to approximately 2% or less. By doing so, the dry separation method and the dry separation device of the present embodiment can be efficiently implemented. 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.

(Embodiment 4)
An embodiment of the dry separation method applied to the present invention will be described with reference to FIG.
FIG. 9 is a schematic view showing an example of a dry separation device used in the dry separation method applied to the present invention. In FIG. 9, 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 separation device shown in FIG. 9 includes a total of two specific gravity difference sorting devices, a first-stage air table type specific gravity difference sorting device 21A and a second-stage air table type specific gravity difference sorting device 21B. The first-stage specific gravity difference sorting device 21A can have the same structure and working conditions as the specific gravity difference sorting device 21 described in the third embodiment.

The coarse particles that have fallen through the pores of the perforated plate 21a of the first-stage specific gravity difference sorting device 21A are controlled in particle size to be smaller than the pore diameter, but have a heavy specific gravity containing heavy minerals having ^{a density of 2.5 g / cm 3 or more.} In many cases, the main component is volcanic glass, and since it contains some pumice and fine powder, the density may be ^{2.5 g / cm 3 or less depending on the raw material and separation conditions.
In this case, in order to sort heavy minerals having a density of 2.5 g / cm 3} or more from the dropped portion of the perforated plate, specific gravity sorting is performed on the second-stage air table.
The amount of the perforated plate dropped from the perforated plate 21a of the first-stage specific gravity difference sorting device 21A is supplied to the second-stage specific gravity difference sorting device 21B via the belt feeder 8 for sorting. The perforated plate 21a of the second-stage specific gravity difference sorting device 21B ^{sets working conditions so that ordinary shirasu having a density of 2.5 g / cm 3} or more is selected as the specific gravity content. However, the working conditions of the second-stage specific gravity difference sorting device 21B can be different from those of the first-stage specific gravity difference sorting device 21A. 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, the frequency of the perforated plate 21a, and the exhaust. At least one of the suction air volume and the like related to the outlet 21e can be made different from that of the first-stage specific gravity difference sorting device 21A. Specifically, in the present embodiment, the pore diameter of the first-stage perforated plate is 1 mm (1 mm mesh), whereas the pore diameter of the second-stage perforated plate is 105 μm (150 mesh).

However, the first-stage perforated plate is not limited to a pore diameter of 1 mm, and a pore diameter of 2 to 0.5 mm can be selected. Further, the pore diameter of the second-stage perforated plate is not limited to 105 μm, and a pore diameter of 75 to 500 μm can be selected.

In the dry separation method of the present embodiment, the weight specific gravity content sorted by the perforated plate 21a of the second-stage specific gravity difference sorting device 21B is discharged from the discharge port 21c of the specific gravity difference sorting device 21B and recovered. The recovered weight specific gravity content has a density of 2.5 g / cm ³ or more. ^{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 density component sorted by the perforated plate 21a of the second-stage specific gravity difference sorting device 21B is discharged from the discharge port 21d of the specific gravity difference sorting device 21B. The discharged light specific gravity component is passed through a sieve 23, which will be described later, via a belt feeder 9.

The dust collected from the perforated plate 21a of the second-stage specific gravity difference sorting device 21B is guided to the cyclone classifier 22 via the conduit 7B connected to the discharge port 21e of the specific gravity difference sorting device 21B. The cyclone classifier 22 is as described above. The overflow fine powder of the cyclone classifier 22 is guided to the bag filter 16 via the pipeline 7I and collected. The recovered fine powder F is used as a raw material for hydraulic lime. The cyclone recovered portion of the underflow portion can be crushed and used as a raw material for the hydraulic lime of the present invention.

The amount of the perforated plate dropped through the hole of the perforated plate 21a of the second-stage specific gravity difference sorting device 21B is discharged from the discharge port 21f of the specific gravity difference sorting device 21B and recovered as a raw material for a shirasu balloon or a raw material for an admixture. do. The recovered perforated plate can be crushed and used as a raw material for the hydraulic lime of the present invention. Depending on the difference in working conditions such as the pore diameter of the perforated plate 21a of the second-stage specific gravity difference sorting device 21B and the type of raw material, the perforated plate dropped through the holes of the perforated plate 21a and discharged from the discharge port 21f , JIS A5002 "Structural lightweight concrete aggregate" may be met, and in this case, the fallen portion of the perforated plate can be recovered as a lightweight aggregate.

Depending on the raw material and working conditions, the amount of the perforated plate dropped from the discharge port 21f through the hole of the perforated plate 21a of the second-stage specific gravity difference sorting device 21B can be recovered with ^{a density of 2.5 g / cm 3 or more.} May be done. In this case, the amount of the perforated plate dropped can be mixed with the fine aggregate D and used.

The sieve 23 has a predetermined mesh size. The mesh size of the sieve 23 can be, for example, 300 μm. The light specific density component of the first-stage specific gravity difference sorting device 21A and the light specific density component of the second-stage specific gravity difference sorting device 21B are guided to the sieve 23 and separated into an upper sieve and a lower sieve component.

The light specific density of the first-stage specific gravity difference sorting device 21A and the light specific gravity of the second-stage specific gravity difference sorting device 21B contain 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. Therefore, the lightweight aggregate can be recovered by sieving with a sieve 23 having a particle size of 0.3 mm.

Further, below the sieve of the sieve 23 is a volcanic glass material having a particle size of less than 0.3 mm. In particular, when the volcanic ejecta sedimentary 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, by crushing a volcanic glass material having a particle size of less than 0.3 mm, it can be used as a raw material or an admixture for the hydraulic lime of the present invention. In the dry separation method of the present embodiment, a large amount of fine powder having a particle size of approximately 0.05 mm or less is classified in advance by the discharge port 21e of the first-stage specific gravity difference sorting device 21A and the second-stage specific gravity difference sorting device 21B. Therefore, the bottom of the sieve 23 contains almost no fine powder. Therefore, a pearlite raw material or a shirasu balloon raw material having good foamability can be obtained under the sieve of the sieve 23.

In utilizing the volcanic glass having a particle size of less than 0.3 mm in the light specific density of the first-stage specific gravity difference sorting device 21A and the light specific density of the second-stage specific gravity difference sorting device 21B, it is not always necessary to sift through the sieve 23. .. FIG. 10 is a modification of FIG. 9, which will be described later in the fifth embodiment. The dry separator shown in FIG. 10 does not have a sieve 23.
As shown in FIG. 10, the light specific gravity component does not need to be sieved by the sieve 23 with a particle size of 0.3 mm, but the sieve 23 is omitted if it conforms to the JIS A5002 “Structural Lightweight Concrete Aggregate” standard. Therefore, the lightweight aggregate can be recovered in a simplified manner.

According to the dry separation method of the present embodiment shown in FIGS. 9 and 10, not only the effect of the third embodiment shown in FIGS. 6 and 8 is obtained, but also the first-stage specific gravity difference sorting device 21A and the second-stage. By using the specific gravity difference sorting apparatus 21B, the yield and sorting ability can be improved. Therefore, the ratio of the recovered heavy specific gravity D, the fine powder F, the light specific gravity under the sieve, and / or the recovered cyclone E2 can be improved, and as a result, the yield of fine aggregate having a ^{density of 2.5 g / cm 3 or more can be improved.} The rate can be increased.

The second-stage specific gravity difference sorting device 21B is not necessarily limited to a separate device. After performing a predetermined amount of dry separation work using the first-stage specific gravity difference sorting device 21A, the perforated plate of the specific gravity difference sorting device 21A is replaced and used in place of the second-stage specific gravity difference sorting device 21B. You can also.

(Embodiment 5)
The fifth embodiment will be described with reference to FIG. In the dry separator shown in FIG. 9, the dust collector floating from the perforated plate 21a of the first-stage specific gravity difference sorting device 21A and the dust collected floating from the perforated plate 21a of the second-stage specific gravity difference sorting device 21B are collected. , It is guided to one cyclone classifier 22 through the pipelines 7A and 7B connected to the discharge port 21e, and the fine particles E2 of the volcanic glass material are separated and recovered, and the fine powder F is separated and recovered by the bag filter 16.

The first-stage specific gravity difference sorting device 21A and the second-stage specific gravity difference sorting device 21B may be used by connecting two stages of devices having the same performance as shown in FIG. 9, but the properties of the raw materials to be charged and the device are porous. At least one or more of the inclination angle of the 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, the frequency of the perforated plate 21a, the amount of sucked air related to the discharge port 21e, etc. In many cases, the working conditions of are changed. Therefore, in order to perform the specific gravity separation composed of the two-stage specific gravity difference sorting device with higher accuracy, it is necessary to finely control the above working conditions with high accuracy.

It is known that the separation performance of the specific gravity difference sorting device is also affected by the amount of sucked air related to the discharge port 21e. The intake air volume related to the pipe line 7A and the pipe line 7B in FIG. 9 is determined by a butterfly valve or the like installed in the pipe depending on the performance and operating conditions of the cyclone classifier 22, the bug filter 16, and the exhaust blower 18. Attempts to adjust either the suction air volume of 7A or 7B affect each other, and it may be difficult to finely adjust the suction air volume of the first and second stages. Therefore, if the cyclone classifier, the bag filter, and the exhaust blower can be operated independently in the first stage and the second stage, high-precision specific gravity separation becomes possible. Therefore, FIG. 10 shows a modified example of the present embodiment in which one set of a cyclone classifier 22B, a bug filter 16B, and an exhaust blower 18B is added to the two-stage specific gravity separating device of FIG.

In FIG. 10, the first-stage specific gravity difference sorting device is 21D, and the second-stage specific gravity difference sorting device is 21E. The light specific density of the first-stage specific gravity difference sorting device 21D and the light specific gravity of the second-stage specific gravity difference sorting device 21E include volcanic glass having a particle size of 0.3 mm or less. Not screened by. Even if the sieve 23 does not sift with a particle size of 0.3 mm, if it conforms to the JIS A5002 “Structural Lightweight Concrete Aggregate” standard, the sieve 23 is omitted and as shown in the modified example shown in FIG. The lightweight aggregate E1 can be recovered in a simplified manner. However, in FIG. 10, the sieve 23 may be used for sieving, for example, with a particle size of 0.3 mm.

Further, in FIG. 10, depending on the working conditions of the second-stage specific gravity difference sorting device 21E, it is possible to reduce the amount of the perforated plate dropped from the discharge port 21f to zero. In this case, the second-stage It is not necessary to sort the fallen part of the perforated plate in the eye specific density difference sorting device 21E, and the weight specific gravity component and the light specific gravity component are separated by the second stage specific gravity difference sorting device 21E, the cyclone classifier 22B connected to the second stage specific gravity difference sorting device 21E, and the bag filter 16B. , Dust collection (cyclone recovery, bug filter recovery) can be simplified by sorting into a total of 4 divisions.

(Embodiment 6)
An embodiment of a dry separation method for volcanic ejecta sedimentary minerals applied to the present invention will be described with reference to FIG.
FIG. 11 is a schematic view showing an example of a dry separation device suitable for use in the method for producing hydraulic lime of the present invention. In FIG. 11, 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 separation device shown in FIG. 11 includes a total of two specific gravity difference sorting devices, a first-stage air table type specific gravity difference sorting device 21D and a second-stage air table type specific gravity difference sorting device 21E. The first-stage specific gravity difference sorting device 21D can have the same structure and working conditions as the specific gravity difference sorting device 21 described in the third embodiment.

^{Depending on the raw material and working conditions, fine aggregate with a density of 2.5 g / cm 3} or more may be mixed in the light specific gravity component discharged from the discharge port 21d of the first-stage specific gravity difference sorting device 21D. In this case, as in the present embodiment shown in FIG. 11, the light specific density component sorted by the first-stage specific gravity difference sorting device 21D is supplied to the second-stage specific gravity difference sorting device 21E, and the specific gravity is concerned. With the difference sorting device 21E, it is possible to separate and collect the heavy specific density component, the perforated plate drop component, the light specific gravity component, and the dust collection component (cyclone recovery component, bag filter recovery component).

Further, in FIG. 11, depending on the working conditions of the second-stage specific gravity difference sorting device 21E, it is possible to reduce the amount of the perforated plate dropped from the discharge port 21f to zero. In this case, the second-stage The eye specific density difference sorting device 21E does not need to sort the fallen perforated plate, and the second stage specific gravity difference sorting device, the cyclone classifier 22B connected to the second-stage specific gravity difference sorting device, and the bag filter 16B are used to collect the heavy specific density, the light specific gravity, and the dust. It can be simplified by sorting the dust (cyclone recovery, bag filter recovery) into a total of four divisions.
Here, the second-stage specific gravity difference sorting device 21E can have the same structure and working conditions as the specific gravity difference sorting device 21 described in the third embodiment.

(Embodiment 7)
An embodiment of a dry separation method for volcanic ejecta sedimentary minerals applied to the present invention will be described with reference to FIG.
FIG. 12 is a schematic view showing an example of a dry separation device suitable for use in the method for producing hydraulic lime of the present invention. In FIG. 12, 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 separation device shown in FIG. 12 includes a total of two specific gravity difference sorting devices, a first-stage air table type specific gravity difference sorting device 21D and a second-stage air table type specific gravity difference sorting device 21E. The first-stage specific gravity difference sorting device 21D can have the same structure and working conditions as the specific gravity difference sorting device 21 described in the third embodiment.

Depending on the raw material and working conditions, pumice stones having a particle size of 0.3 mm or more may be mixed in the cyclone recovered portion discharged from the discharge port 21e of the first-stage specific gravity difference sorting device 21D. In this case, as in the present embodiment shown in FIG. 12, the cyclone recovered portion collected by the cyclone classifier among the dust collectors sorted by the first-stage specific gravity difference sorting device 21D is used in the second stage. It is supplied to the specific gravity difference sorting device 21E and separated into the heavy specific density component, the perforated plate drop component, the light specific gravity component, and the dust collection component (cyclone recovery component, bag filter recovery component) by the second-stage specific gravity difference sorting device 21E. It can be recovered.

Further, depending on the working conditions of the second-stage specific gravity difference sorting device 21E, it is possible to eliminate the amount of the perforated plate dropped from the discharge port 21f to zero. By the cyclone classifier 22B and the bug filter 16B connected to the cyclone classifier 22B, it is possible to simplify the selection by dividing the weight specific density, the light specific density, and the dust collector (cyclone recovered portion, bag filter recovered portion) into a total of four divisions.

In the example shown in FIG. 9, the dry separation devices used in the dry separation method for volcanic ejecta sedimentary minerals are the first-stage air table type density difference sorting device 21A and the second-stage air table type density difference sorting device 21B. A total of two specific gravity difference sorting devices 21 are provided. Further, in the examples shown in FIGS. 10 to 12, a total of two specific gravity difference sorting devices 21 including a first-stage air table type specific gravity difference sorting device 21D and a second-stage air table type specific gravity difference sorting device 21E are used. I have. However, the dry separation method and the dry separation device applied to the present invention are not limited to a total of two specific gravity difference sorting devices, and may be a total of three or more. For example, when the density of the weight specific density D by the first-stage specific gravity difference sorting device does ^{not reach 2.5 g / cm 3} or more, or when the specific gravity difference D by the second-stage specific gravity difference sorting device or the perforated plate drops. When the density of is not 2.5 g / cm ³ or more, it is preferable because the density of the weight specific gravity D can be ensured to be ^{2.5 g / cm 3} by the third-stage specific gravity difference sorting device. .. Further, it is preferable because the yield and sorting ability of the fine powder F used as a raw material of hydraulic lime, the light specific density under the sieve and / or the recovered cyclone can be further increased. In addition, when the raw material has a large amount of water, or when the separation between the heavy density component and the light specific density component is insufficient in the first-stage or second-stage specific gravity difference sorter, or when the mineral composition of the raw material (crystalline and volcanic glass) Even when the quality ratio) is significantly different from that of the examples, the dry separation method can be performed by using a dry separation device provided with a third-stage specific gravity difference sorting device or a higher specific gravity difference sorting device.

(Embodiment 8)
An embodiment of a dry separation method and a dry separation device for volcanic ejecta sedimentary minerals applied to the present invention will be described. FIG. 13 is a schematic view showing an example of a dry separation device suitable for use in the method for producing hydraulic lime of the present invention. In FIG. 13, 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 separation device shown in FIG. 13 includes an air flow classification device 10. The airflow classifying device 10 has a cyclone classifying machine group 12 to 14 for coarse grain recovery, a cyclone classifying machine 15 for fine grain recovery, and a bug filter 16 for fine powder recovery connected to the cyclone classifying machine. There is. More specifically, the airflow classifier 10 includes a plurality of cyclone crushers 11A, 11B, 11C, a plurality of cyclone classifiers 12 to 15, a bug filter 16, and pipelines 17A to 17I connecting them. ing. This dry separation device further includes a total of two specific gravity difference sorting devices 21 including a first-stage air table type specific gravity difference sorting device 21A and a second-stage air table type specific gravity difference sorting device 21B.

The airflow classification device 10 shown in FIG. 13 is the same as the airflow classification device 10 described in the first and second embodiments. The number of cyclone crushers is not limited to the three shown in the figure, and the number of cyclone classifiers in the cyclone classifier group for collecting coarse grains is not limited to the three shown.

The airflow classifier 10 has a rotary feeder 20, and depending on the moisture content of the normal shirasu, whether the rotary feeder 20 supplies the normal shirasu to the cyclone classifier 13 or the cyclone crusher 11A is supplied with the normal shirasu. , Or both can be selected to supply normal shirasu. Normally, Shirasu has a water content of about 20% when not dried. When the raw material ordinary shirasu has a water content of about 10 to 20%, it is preferable to supply the ordinary shirasu to the cyclone crusher 11A and crush and dry it in the cyclone crushers 11A to 11C. When the raw material, ordinary shirasu, has a water content of about 4 to 10%, cyclone crushers 11A to 11C can be used, or the rotary feeder 20 and cyclone crushers 11A to 11C can be used in combination. When the raw material ordinary shirasu has a water content of less than 4%, the ordinary shirasu can be supplied from the rotary feeder 20 to the cyclone classifier 13.

The illustrated sieve 4 removes gravel having a particle size of more than 5 mm as an upper sieve, and the balance is supplied to the air flow classification device 10 as a lower sieve. Instead of the sieve 4, a machine that grinds the particle size of the raw material, ordinary shirasu, to 5 mm or less can also be used.

The classification of ordinary silas by the airflow classifying device 10 is the same as that of the airflow classifying device 10 described in the first and second embodiments, and the cyclone classifying machine 12 collects coarse particles having a particle size of about 0.3 to 5 mm. The cyclone classifier 15 collects fine particles with a particle size of about 0.05 to 0.3 mm (average particle size of about 0.1 mm), and the bag filter 16 collects fine particles with a particle size of 0.05 mm or less (average particle size of about 0.033 mm). ) Collect the fine powder. The recovered fine powder F is used as a raw material for hydraulic lime. Further, the fine particles having a particle size of about 0.05 to 0.3 mm are passed through a belt feeder 9 as described later and passed through a sieve 23 described later.

The coarse grains are supplied to the first-stage specific gravity difference sorting device 21A. The first-stage specific gravity difference sorting device 21A and the second-stage specific gravity difference sorting device 21B have the same structure and operation as the first-stage specific gravity difference sorting device 21A and the second-stage specific gravity difference sorting device 21B described in the fourth embodiment. Can be a condition.

In the example shown in FIG. 13, the dry separation device used in the dry separation method of the present embodiment is the first-stage air table type specific gravity difference sorting device 21A and the second-stage air table type specific gravity difference sorting device 21B. A total of two specific gravity difference sorting devices 21 are provided. However, the dry separation method and the dry separation device of the present embodiment are not limited to a total of two specific gravity difference sorting devices, and may be a total of three or more. For example, when the density of the weight specific density D by the first-stage specific gravity difference sorting device does ^{not reach 2.5 g / cm 3} or more, or when the specific gravity difference D by the second-stage specific gravity difference sorting device or the perforated plate drops. When the density of is not 2.5 g / cm ³ or more, it is preferable because the density of the weight specific gravity D can be ensured to be ^{2.5 g / cm 3} by the third-stage specific gravity difference sorting device. .. In addition, when the raw material has a large amount of water, or when the separation between the heavy density component and the light specific density component is insufficient in the first-stage or second-stage specific gravity difference sorter, or when the mineral composition of the raw material (crystalline and volcanic glass) Even when the quality ratio) is significantly different from that of the examples, the dry separation method can be performed by using a dry separation device provided with a third-stage specific gravity difference sorting device or a higher specific gravity difference sorting device.

The weight specific gravity content sorted by the perforated plate 21a of the first-stage specific gravity difference sorting device 21A is discharged from the discharge port 21c of the specific gravity difference sorting device 21A and collected. The recovered weight specific gravity content D has a density of 2.5 g / cm ³ or more. ^{This weight specific gravity content D 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 density component sorted by the perforated plate 21a of the first-stage specific gravity difference sorting device 21A is discharged from the discharge port 21d of the specific gravity difference sorting device 21A. The discharged light specific gravity component is applied to a sieve 23, which will be described later, via the belt conveyor 6 and the belt feeder 9.

The dust collected from the perforated plate 21a of the first-stage specific gravity difference sorting device 21A is guided to the cyclone classifier 22 via the conduit 7A connected to the discharge port 21e of the specific gravity difference sorting device 21A. The cyclone classifier 22 classifies lighter fine powder as an overflow component from the dust collector. The cyclone recovered portion of the underflow portion is recovered as the shirasu balloon raw material or the admixture raw material E2. Further, the fine powder of the overflow of the cyclone classifier 22 is guided to the bag filter 16 through the pipe line 7C connected to the pipe line 17I and collected. The bug filter 16 has already been described. The recovered fine powder F is used as a raw material for hydraulic lime.

The ordinary shirasu that has fallen from the perforated plate 21a of the first-stage specific gravity difference sorting device 21A is supplied to the second-stage specific gravity difference sorting device 21B for sorting.
The weight specific density component D sorted by the perforated plate 21a of the second-stage specific gravity difference sorting device 21B is discharged from the discharge port 21c of the specific gravity difference sorting device 21B and collected. The recovered weight specific gravity content D has a density of 2.5 g / cm ³ or more. ^{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 density component sorted by the perforated plate 21a of the second-stage specific gravity difference sorting device 21B is discharged from the discharge port 21d of the specific gravity difference sorting device 21B. The discharged light specific gravity component is passed through a sieve 23, which will be described later, via a belt feeder 9.

The dust collected from the perforated plate 21a of the second-stage specific gravity difference sorting device 21B is guided to the cyclone classifier 22 via the conduit 7B connected to the discharge port 21e of the specific gravity difference sorting device 21B. The cyclone classifier 22 is as described above. The overflow fine powder of the cyclone classifier 22 is guided to the bag filter 16 via the pipe line 7C connected to the pipe line 17I, and the fine powder F is collected by the bag filter 16. The fine powder F 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. Therefore, the fine powder F is suitable as a raw material for the hydraulic lime of the present invention. The cyclone recovered portion of the underflow portion can be crushed and used as a raw material for the hydraulic lime of the present invention.

The amount of the perforated plate dropped through the hole of the perforated plate 21a of the second-stage specific gravity difference sorting device 21B is discharged from the discharge port 21f of the specific gravity difference sorting device 21B and recovered as a shirasu balloon raw material or an admixture raw material E2. do. The recovered perforated plate can be crushed and used as a raw material for the hydraulic lime of the present invention. Depending on the pore size of the perforated plate 21a of the second-stage specific gravity difference sorting device 21B, the amount of the perforated plate dropped through the hole of the perforated plate 21a and discharged from the discharge port 21f is JIS A5002 "Structural lightweight concrete aggregate. In this case, the fallen portion of the perforated plate can be recovered as a lightweight aggregate. Further, the amount of the perforated plate dropped from the discharge port 21f through the hole of the perforated plate 21a of the second-stage specific gravity difference sorting device 21B is 2.5 g / cm ³ or more in density depending on the raw material and working conditions. May be recovered. In this case, the amount of the perforated plate dropped can be mixed with the fine aggregate D and used.

The sieve 23 has a predetermined mesh size. The mesh size of the sieve 23 can be, for example, 300 μm. On the sieve 23, the fine particles of the underflow of the cyclone classifier 15 of the air flow classifier 10, the light density of the first-stage specific gravity difference sorting device 21A, and the light specific density of the second-stage specific gravity difference sorting device 21B. And divide it into the upper sieve and the lower sieve.

The fine particles classified as the underflow component of the cyclone classifier 15 of the air flow classifier 10 are mainly volcanic glass and contain 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 E1. Further, the light specific density component of the first-stage specific gravity difference sorting device 21A and the light specific gravity component of the second-stage specific gravity difference sorting device 21B also contain 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 E1. Therefore, the lightweight aggregate E1 can be recovered by sieving with a sieve 23 having a particle size of 0.3 mm.

Further, below the sieve of the sieve 23 is volcanic glass having a particle size of less than 0.3 mm. In particular, when the volcanic ejecta sedimentary mineral is shirasu as in the present embodiment, volcanic glass having a particle size of less than 0.3 mm foams by heating, and is therefore useful as a pearlite raw material, a shirasu balloon raw material, or an admixture raw material E2. Is. In the dry separation method of the present embodiment, fine powder having a particle size of 0.05 mm or less is classified in advance by the air flow classification device 10, so that the sieve 23 contains almost no fine powder. Therefore, the shirasu balloon raw material E2 having good foamability can be obtained under the sieve of the sieve 23. The pearlite raw material or the shirasu balloon raw material E2 can be further pulverized into fine powder F and used as an admixture. Therefore, the bottom of the sieve 23 can be pulverized to use the raw material for the hydraulic lime of the present invention.

In the dry separation method of the present embodiment, ordinary sieves are classified into coarse particles, fine particles, and fine powder by the air flow classification device 10, and then the coarse particles are weighted by the air table type first-stage density difference sorting device 21A. Relative density, light density, perforated plate drop and dust collection are sorted, and then the weight density, light density, perforated plate drop and dust collection are performed by the second-stage specific gravity difference sorting device 21B. By sorting into minutes and sieving the fine particles and the light density component, the ordinary silas can be separated into four components: the heavy specific density component D, the upper sieving E1, the lower sieving E2, and the fine powder F. .. Relative density D is mainly composed of crystalline minerals and contains almost no volcanic glass. Therefore, the weight specific gravity content D has a high density and exceeds ^{2.5 g / cm 3.} Further, the upper sieve E1, the lower sieve E2, and the fine powder F are mainly composed of volcanic glass and contain almost no crystalline minerals. Therefore, the crystalline minerals that can have a heavy specific gravity are hardly mixed in the upper sieve E1, the lower sieve E2, and the fine powder F. Therefore, according to the dry separation method of the present embodiment, no crushing step is required, and even when crushed, it contains almost no hard crystalline minerals, so that the crusher is less worn during crushing and contains almost no crystalline minerals as impurities. Since there is no such material, a raw material for hydraulic lime having a high volcanic glass component ratio can be obtained. Further, according to the dry separation method of the present embodiment, the yield of fine aggregate having a ^{density of 2.5 g / cm 3 or more can be increased.} Further, the weight specific gravity content has a small content of a dust collector having a particle size of 0.15 mm or less, and satisfies the requirement of a wide particle size distribution of 0.15 mm to 5 mm specified in "sand" of JIS A5308. Further, since the weight specific gravity content hardly contains porous particles such as pumice having a high water absorption rate, the water absorption rate satisfies the standard of "sand" of JIS A5308 required as a fine aggregate.

Further, according to the dry separation method of the present embodiment, the weight specific gravity content D is used as a fine aggregate, the upper sieve E1 is used as a lightweight aggregate in volcanic glass, and the lower E2 is used as a pearlite raw material in volcanic glass. As a raw material for silas balloon, further crushed as a raw material for hydraulic lime of the present invention, fine powder F as a raw material for hydraulic lime of the present invention, an admixture in volcanic glass, or a mixed cement raw material having a pozzolanic effect, respectively. It can be used effectively, in other words, there is no unnecessary residue.

According to the dry separation method of the present embodiment, before sorting by the specific gravity difference sorting device 21, the coarse particles, the fine particles, and the fine powder, which have been surface-dried by the air flow classification device 10, are classified in advance. The coarse particles supplied to the difference sorting device 21 contain almost no fine powder that causes clogging of the perforated plate 21a, and thus it is possible to suppress the occurrence of operational troubles due to clogging. Further, in the specific gravity difference sorting by the specific gravity difference sorting device 21, the narrower the particle size distribution width of the powder or granular material to be sorted, the easier it is to sort. Since only the coarse particles are sorted by the specific density difference sorting by the specific gravity difference sorting device 21, the sorting ability of the specific gravity difference sorting device 21 can be enhanced.

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.

(Volcanic glass material)
The residual volcanic glass material obtained by separating the fine aggregate by the dry separation method of each of the above-described embodiments exceeds 0.3 mm by particle size by sieving and dust collection, and is 0.05 mm to 0.3 mm, 0. It can be separated into 3 types of less than 05 mm. Of these, those exceeding 0.3 mm can be used as a lightweight aggregate, and those having a thickness of 0.05 mm to 0.3 mm can be used as a pearlite raw material or a shirasu balloon raw material or further crushed and used as a hydraulic lime raw material of the present invention. Those having a thickness of less than .05 mm can be used as they are or further pulverized as the raw material for hydraulic lime of the present invention. 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 material having these particle sizes can be exemplified by a vibration mill. In addition to the vibration mill, various mills such as a roller mill and a JET mill can also be used.
Among the volcanic glass materials, those with a particle size of less than 0.05 mm and those obtained by crushing the volcanic glass material recovered by a bag filter for collecting fine powder have a density of 2.4 g / cm ³ or less and a loss on ignition. Is 3.5% or less.

Ordinary silas separated by the above-mentioned dry separation method and having a particle size of less than 0.05 mm, separated and obtained by crushing a particle size of 0.05 mm to 0.3 mm, and obtained grains. By further crushing a material having a diameter of less than 0.05 mm to make it ultrafine and firing lime at 900 to 1150 ° C., at least one selected from free CaO, belite, wallastnite and guerenite can be obtained. A hydraulic lime containing, preferably a hydraulic lime containing 3 to 35% by mass of belite, can be obtained.
Therefore, a suitable hydraulic lime of the present invention is a hydraulic lime containing 3 to 35% by mass of belite, which is made from lime and fine powder of volcanic glass material separated from volcanic ejecta sedimentary minerals. In other words, the hydraulic lime of the present invention is a hydraulic lime produced by blending lime and fine powder of volcanic glass material separated from volcanic ejecta sedimentary minerals and containing 3 to 35% by mass of belite. be. The mixing ratio of lime and volcanic ejecta sedimentary minerals is preferably in the range of 85: 15 to 45:55 by weight. The firing temperature of the mixture of lime and volcanic ejecta sedimentary minerals is preferably in the range of 900 to 1150 ° C. If the temperature is lower than 900 ° C., a fired product containing a predetermined amount of belite cannot be obtained, and if the temperature exceeds 1150 ° C., the fired product may become a hard lump. The calcination time depends on the amount of the mixture of lime and volcanic ejecta sedimentary minerals, but when an electric furnace is used, it can be about 1 to 104 hours. A rotary kiln or a fluidized bed furnace can be used in addition to the electric furnace, and the firing time is not limited to 1 to 104 hours because it is affected by the performance and specifications of the firing furnace. The hydraulic lime of the present invention is a recyclable hydraulic lime whose starting material is a natural material. Therefore, unlike the natural hydraulic lime NHL, the production area is not limited, and since shirasu is usually used as a starting material, hydraulic lime can be obtained at low cost. Then, a white cured product having a strength equal to or higher than that of natural hydraulic lime NHL can be obtained.
In addition, Shirasu is a volcanic deposit that has been weathered for many years, is mainly composed of volcanic glass, is characterized by a wide particle size distribution, is porous, and is easily crushed, so the energy required for crushing is required. Few. Shirasu is a natural resource, contains no harmful substances, and can be recycled. Since silas has a large specific surface area and is highly reactive by using particles with a small particle size, it can be synthesized at a low temperature, the energy required for heating is reduced, and CO _{2 which causes global warming.} Is suppressed. On the other hand, in the current production of Portland cement, heating and firing at 1450 ° C. is performed, and low temperature is being studied to suppress _{CO 2 generation as a measure against global warming, but it has not progressed.}
Further, since the present invention is synthesized at a low temperature, the synthetic product does not become a lump and can be easily pulverized. Therefore, when the compound is crushed, heavy metals (Cr, Ni, etc.) mixed from the crusher are less mixed. Currently used cement is fired at a temperature of 1400 ° C. or higher to generate clinker, and this clinker is finely pulverized to produce cement products. A great deal of energy is also used for this crushing and fine powder recovery. In addition, high-temperature firing and mixing of wear components from the structural material of the crusher are unavoidable.

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

(Examples 1 to 6, Comparative Examples 1 to 3)
In Examples 1 to 6 and Comparative Examples 1 to 3, the influence of the blending ratio (mass%) of lime and shirasu was observed.
Using the equipment and method shown in FIG. 13, Kushira Silas (water content 4.6%) produced in Kushira-cho, Kanoya City, Kagoshima Prefecture, as a raw material volcanic ejecta deposit mineral, is sieved with an opening of 5 mm. Fine powders having a particle size of less than 0.05 mm were obtained from those sorted in 4. The average particle size of this fine powder was 0.033 mm, the water content was 3.0%, and the density was 2.48 g / cm ³ . The mass percentage of the fine powder C with respect to the ordinary shirasu before being put into the dry separator was 2.4%.

This fine powder and Tokunoshima lime were blended in various proportions shown in Table 1 and calcined at a predetermined firing temperature and firing time.

The fine powder and Tokunoshima lime were mixed and pulverized with a planetary ball mill using alumina balls having a diameter of 15 mm before firing. The average particle size of the mixture before firing after crushing with a planetary mill was 0.006 mm. Next, the mixture was transferred to a porcelain pan, held in an electric furnace at 1000 ° C. for 5 or 20 hours, then removed from the furnace and rapidly cooled. The obtained fired product was examined by powder X-ray diffraction.

[Baked product]
(Visual inspection)
In Examples 1 to 5, there were no lumps after firing, and a greenish powder was obtained.
In Example 6, hard grains were produced, and the color tone was reddish with the green disappearing.
This tendency became stronger in Comparative Examples 1 and 2.

(Powder X-ray diffraction result)
The formation of belite (β-Ca ₂ SiO ₄ ), free CaO _{, wallastonite (CaSiO 3} ), gelenite (Ca ₂ Al ₂ SiO ₇ ), and glass phase was confirmed. As an example, FIG. 14 shows an X-ray diffraction pattern of the hydraulic lime synthesized in Example 4.
Among the products, belite (β-Ca ₂ SiO ₄ ) had the highest diffraction peak intensity in Example 5, and the diffraction peak intensity decreased as the amount of shirasu added further increased.
The diffraction peak of free CaO decreased as the ratio of Shirasu increased, and disappeared in Comparative Example 2.
Wallastnite (CaSiO ₃ ) grew when the diffraction peak was observed from Example 5 and the shirasu ratio became high.
Guerenite (Ca ₂ Al ₂ SiO ₇ ) grew rapidly from Example 5.
In the composition of Example 2, it was found that the diffraction peak of belite became stronger by extending the firing time of 5 hours to 20 hours, and the synthesis reaction proceeded by lengthening the holding time.

(Mortar test)
In the mortar test, hydraulic lime generally needs to be pulverized, but in Examples 1 to 5, there were no agglomerates and crushing was not necessary. Example 6 and Comparative Examples 1 and 2 were pulverized and pulverized using a mortar.

The fired product and standard sand were mixed at a ratio of 1: 3, and water was added until a paste that could be poured was obtained. In the addition of water, since it contains free CaO, it generates heat and evaporates due to the reaction with water. Therefore, the paste was added little by little while observing the situation, and finally a paste was prepared with a paste mixer (manufactured by JAPAN UNIX). The obtained paste was poured into a plastic mold.
After molding, it is kept in an environment of 90% or more humidity for 2 days, then immersed in water for 28 days, then removed from the mold and left to dry at room temperature for 1 week, and then Shimadzu Autograph / AG-10TA) strength. The compressive strength was measured with a measuring machine.
As Comparative Example 3, natural hydraulic lime NHL5 (BOEHM, France) was used instead of the calcined product.
The results are shown in Table 2.

Since each Example and Comparative Example contain free CaO, _{the amount of water required for CaO to be digested to Ca (OH) 2} is required, and the amount of water for pasting depends on the residual amount of CaO. It is changing little by little. Digestion refers to a reaction that produces _{Ca (OH) 2} by adding water to CaO.
Examples 1 to 6 were cured by curing in water, and their compressive strength was higher than that of NHL5 (Comparative Example 3). The color tone of Examples 1 to 6 was white. From this result, it was found that the hydraulic lime of the present invention has a strength equal to or higher than that of NHL5 (Comparative Example 3), which is known as a high-strength natural hydraulic lime.
On the other hand, in Comparative Example 1 and Comparative Example 2, the compressive strength of the sample could not be measured because it did not harden in water curing and could not be demolded.

(Examples 7 to 12)
In Examples 7 to 12, the influence of the holding time of firing at 1000 ° C. was observed.
Shirasu fine powder having a particle size of less than 0.05 mm was obtained in the same manner as in Examples 1 to 6. This fine powder and Tokunoshima lime were mixed at a ratio of Tokunoshima lime to Shirasu (Tokunoshima lime: Shirasu) at 70:30, and mixed and pulverized with a planetary ball mill using an alumina ball having a diameter of 15 mm. Tokunoshima lime is a fine powder of crushed and classified coral limestone from Tokunoshima. The average particle size of the mixture before firing after crushing with a planetary mill was 0.006 mm. Next, it was transferred to a porcelain dish and fired in an electric furnace at a firing temperature of 1000 ° C. and various firing times of 1 to 104 hours shown in Table 3. The obtained fired product was examined by powder X-ray diffraction.
Next, the same mortar preparation as in Examples 1 to 6 was carried out, and the compressive strength was examined.

(Results of powder X-ray analysis of fired product)
From the powder X-ray analysis results of the calcined products of Examples 7 to 12, it was found that the free CaO decreased as the calcining time became longer, while the diffraction peak of belite became stronger and the synthesis proceeded. rice field. At the same time, the diffraction peaks of wallastnite and guerenite also increased. In Example 12, which has the longest firing time of 104 hours, a large amount of belite is produced, but a large amount of wallastite and gerenite are also produced, and CaO is consumed due to the reaction and the amount of free CaO is small. It was.

(Strength test result)
From Table 3, even in Example 7 in which the firing time was 1 hour, it was cured by underwater curing and had a strength of 8 MPa or more. When the firing time is short, the formation of belite, which is a hydraulic substance, is small, but it is considered that calcium hydroxide generated by digestion and the unreacted silica component are cured by a pozzolan reaction due to the presence of a large amount of unreacted free CaO. Be done.

(Example 13)
Example 13 looked at the effect of pre-digestion of the fired product.
In Examples 1 to 12 described above, water is added to the calcined product (hydraulic lime of the present invention) together with standard sand at the time of mortar preparation, and quicklime (CaO) is digested and mixed with sand at the same time. However, it is also possible to prepare a paste by adding standard sand and water to the previously digested product. Therefore, Example 13 described below is an example in which standard sand and water are added to the digested product to prepare a paste.

The raw material of the fired product is the same as in Examples 1 to 6. The ratio of Tokunoshima lime and Shirasu was mixed at a ratio of 70:30 (weight ratio), and calcined at 1000 ° C. for 20 hours in the same manner as in Example 9. Water was sprayed on the obtained fired product and left at room temperature in a closed container for 24 hours. After being left to stand, it was confirmed by powder X-ray analysis that CaO disappeared and Ca (OH) _{2 was produced.} The amount of sprayed water was about 30% of the weight of the fired product.
After digestion, standard sand and water were added at the ratios shown in Table 4 to prepare a paste, and the obtained paste was poured into a plastic mold in the same manner as in Example 9. After molding, it was kept in an environment of 90% or more humidity for 2 days, then removed from the mold soaked in water for 28 days, left at room temperature for 1 week to dry, and then Shimadzu Autograph (AG-10TA) strength measuring machine. The compressive strength was measured at.

Table 4 shows the composition ratio of the mortar formulation and the compressive strength of the molded product. From Table 4, high compressive strength was also obtained in Example 13 in which standard sand and water were added to the digested product to prepare a paste.

(Example 14, Comparative Example 4)
In Example 14 and Comparative Example 4, the influence of the firing temperature was observed.
The raw material of the fired product is the same as in Examples 1 to 6. The ratio of Tokunoshima lime and Shirasu was mixed at a ratio of 70:30 (weight ratio) and calcined at 850 ° C. and 1150 ° C. for 8 hours. The obtained fired product was examined by powder X-ray diffraction.
The firing conditions are shown in Table 5.

As a result of powder X-ray analysis, in Comparative Example 4 in which the firing temperature was 850 ° C., only the diffraction peak of free CaO appeared, and the diffraction peak of belite was not observed. On the other hand, in Example 14 in which the firing temperature was 1150 ° C., the production of gerenite increased, but the fine powder of the calcined product exhibited hydraulic lime.

(Examples 15 and 16, Comparative Examples 5 to 7)
Examples 15 and 16 are examples in which fine shirasu granules are used instead of standard sand.
A mortar was prepared using the same fired product as in Example 4 using shirasu fine particles having a particle size of 0.18 to 0.85 mm obtained by classifying ordinary shirasu (Kushira shirasu) using the apparatus and method shown in FIG. At the time of preparation, Example 15 was subjected to underwater curing for 4 weeks, and Example 16 was subjected to underwater curing for 8 weeks.

Since the shirasu fine granules have a lighter bulk specific gravity than the standard sand, the mortar composition was set to have the same volume as the standard sand. The weight ratio of standard sand and Shirasu fine granules is as shown in Table 6.

Table 7 shows the composition of Tokunoshima lime and Shirasu fine powder before firing, the firing time, the composition of mortar, the curing period in water, and the compressive strength of the molded product.
Further, as Comparative Examples 5 and 6, CaO obtained by heat-decomposing _{the commercially available reagent Ca (OH) 2} was used instead of Tokunoshima lime and shirasu fine powder as raw materials of Examples 15 and 16, and Examples 15 and 6 were used. A mortar was prepared in the same manner as in 16. Further, as Comparative Example 7, instead of Tokunoshima lime and shirasu fine powder as raw materials of Examples 15 and 16, a fired product obtained by _{heating Tokunoshima lime at 900 ° C. for 1 hour and decomposing it (CaCO 3} → CaO + CO _{2) was used.}

Examples 15 and 16 had high compressive strength. Comparing Example 15 and Example 16, the color tone of the molded product became whitish as the underwater curing became longer, and the demolded surface copied the smoothness of the contact surface of the mold, and was a very smooth surface. Had.
On the other hand, Comparative Example 5 and Comparative Example 6 were very brittle although they maintained their shape after being cured in water, and the strength could not be measured. Further, in Comparative Example 7, it was confirmed by powder X-ray analysis of the calcined product that CaCO ₃ was not observed and that it was quicklime CaO. Due to the heat generated by the digestion of CaO, the added water evaporates, and a large amount of water is required to pour it into a mold and form a paste. The molded product of Comparative Example 7 was solidified but had low strength.

From the results of Examples 15 and 16 and Comparative Examples 5 and 7, the compressive strength of Examples 15 and 16 is not only cured by the pozzolanic reaction _{between Ca (OH) 2} and SiO _{2 but also the fired product.} In addition to the curing of the hydraulic substance belite contained therein, _{it is considered that the SiO 2} component contained in the glass phase is active and further promotes the curing by the pozzolan reaction.

(Examples 17 and 18, Comparative Example 8)
Examples 17 and 18 are examples in which a paste test of water-soluble lime was performed. Synthetic water obtained by firing the calcined products of Examples 10 and 11, that is, a mixture having a composition of 70% Tokunoshima lime and 30% shirasu at 1000 ° C. for 40 hours and 64 hours without adding standard sand or the above-mentioned fine shirasu granules. Hard lime was used. Only water was added to this synthetic hydraulic lime to prepare a paste with a paste mixer, and the paste was poured into a plastic mold in the same manner as in each of the above-mentioned examples to obtain a molded product. After molding, the compressive strength was examined in the same manner as in each of the above-mentioned examples.
As Comparative Example 8, water was added to commercially available Portland cement to prepare a paste, which was poured into a plastic mold to obtain a molded product.

Table 8 shows the mortar composition, the curing time in water, and the compressive strength of the molded product.
From Table 8, it was found that the synthetic hydraulic limes of Examples 17 and 18 were inferior in compressive strength to the Portland cement of Comparative Example 8, but the paste cured product also had sufficient strength.

(Examples 19 and 20)
In Examples 19 and 20, instead of the ordinary shirasu added to Example 1 and the like, weathered pumice in the Kanoya area containing a large amount of volcanic deposits (Example 19) and Sakurajima volcanic ash (Example 20) are used as starting materials. , Hydraulic lime was synthesized using the fine powder classified by the same process as in Example 1.

Example 19 was Kanoya soil, and dust collector recovery powder at the time of drying of weathered pumice was used. The recovered fine powder had an average particle size of 0.026 mm. Example 20 is Sakurajima volcanic ash, and it is known that the ejected new volcanic ash contains a large amount of soluble volcanic glass, and this was used. The recovered fine powder had an average particle size of 0.031 mm.

Tokunoshima lime and fine powder were mixed in the ratio (weight ratio) shown in Table 9 and fired at a predetermined firing temperature and firing time. The obtained fired product was subjected to a mortar test. Table 9 also shows the mortar composition, the curing time in water, and the compressive strength of the molded product.
From Table 9, high-strength molded products were also obtained in Examples 19 and 20 in which Kanoya soil and Sakurajima volcanic ash were used as the volcanic ejecta deposit minerals.

(Result of powder X-ray diffraction of fired product)
Table 10 shows the peak intensity ratio of the product in the calcined product obtained by calcining the mixture of Tokunoshima lime and volcanic ejecta sedimentary mineral fine powder in Examples 1 to 20 and Comparative Examples 1 to 4 described above. In quantifying, the following rules were set and calculated. Diffraction peaks that do not overlap with other compounds were selected from the diffraction peaks of each compound (4 types), and the ratio of the intensity value of the diffraction peak to the total value of the 4 types of diffraction peak intensity values was determined.

The 2θ of the selected diffraction peak is as follows.
Quicklime CaO 2θ = 37.3 °
Belite β- ₂ CaO · SiO 2 2θ = 41.2 °
Guerenite Ca ₂ Al ₂ SiO ₇ 2θ = 31.3 °
Wallastnite CaSiO ₃ 2θ = 30.0 °

From the results of powder X-ray diffraction peak intensity determination in Table 10, the composition ratio of the calcined product of the mixed powder of the fine powder such as Shirasu and Tokunoshima lime fine powder using the fine powder obtained by classifying the ordinary shirasu etc. into the air flow as the silica source. The preferred range of
Quicklime (CaO): 5 to 95% by mass,
Belite: 3 to 35% by mass,
Guerenite: <50% by mass,
Wallast Night: <50% by mass,
Met.

Further, from the results of Examples 1 to 20 and Comparative Examples 1 to 8, the weight ratio of Tokunoshima lime fine powder and Shirasu fine powder is preferably in the range of 85: 15 to 45:55, and the firing temperature is 900 ° C to 1150 ° C. The range of was suitable.

(Examples 21 to 23)
In Examples 21 to 23, the firing of Tokunoshima lime and shirasu fine powder was fired for a short time by a rotary kiln or a fluidized bed firing, and the fired product was evaluated. The rotary kiln is fired while rolling a tubular heating zone, and a fired product can be continuously obtained, which is excellent in mass productivity. Further, fluidized bed firing is a method in which high-temperature combustion gas is blown up from under a heat medium and fired while the heat medium is flowing, and is a compact heating means.

When firing the raw material mixed powder in a porcelain dish in an electric furnace as in Examples 1 to 6, the raw material silas particles and Tokunoshima lime particles are always in close proximity during heating, and a chemical reaction occurs through the particle contact points. Proceeds. On the other hand, since the rotary kiln moves while rolling in the tubular heating zone, it is difficult for the reaction to proceed because there are few contact points between the mixed powders and the raw material particles. Further, in the fluidized bed firing, the mixed powder is blown up by the high temperature combustion gas from below. Therefore, the mixed powder was granulated and fired as in Example 21 below.

Further, in the mortar test of the fired product, particles having a particle size of 0.18 to 0.85 mm obtained by sieving Shirasu instead of standard sand were used as the fine aggregate. The mixing ratio with the fired product was 1: 2 (weight ratio). The reason is that the volume ratio to the calcined product is adjusted to the case where the standard sand is used because of the difference in bulk density between the standard sand and this Shirasu fine aggregate.

(Example 21) Baking in a rotary kiln / preparation of mixed powder before baking Shirasu fine powder (average particle size 0.0384 mm) obtained by classification and Tokunoshima lime powder were mixed in a V-type mill at a ratio of 30:70. .. After that, the crushing was not performed with the planetary mill carried out in Example 1. 18 parts by weight of an 8% polyvinyl alcohol aqueous solution was added to 100 parts by weight of the mixed powder, and granulation was performed by stirring with a universal stirrer. After the granulated product was dried at 50 ° C., it was divided by a flue having a mesh size of 3 mm, and the material that passed through the flue was used as a raw material for firing.
-Burning in a rotary kiln A rotary kiln manufactured by Koyo Thermo System, which has a SUS core tube with an inner diameter of 148 mm and a length of 2000 mm, was fired at 1000 ° C. The time from the input of the raw material to the removal of the furnace was about 1 hour, and the fired product maintained the granulated shape and had a pale ocher color.

(Powder X-ray analysis result)
In addition to free CaO, the formation of wallastnite and guerenite was confirmed, there was a swelling of the baseline near the diffraction line angle of belite, and a weak diffraction line of quartz was also observed. It is considered that the belite phase cannot be fully grown due to the short heating time, and unreacted quartz remains.

(Examples 22 and 23) Firing on a fluidized bed Firing on a gas-heated fluidized bed using the same granulated body as the rotary kiln calcining in Example 21 and using a mullite heat medium of 1.7 mm or less manufactured by Itochu Ceratech. Was carried out. The total gas flow rate (propane gas + air) at the time of firing at 1000 ° C. was 50 Nm ³ / h.
The charged granules were heated while floating on a fluidized bed, and in a few minutes, red-hot particles were discharged from the furnace mouth and cooled in a SUS container (Example 22). Some of the particles that popped out were black aggregated particles in which the granulation body was welded. The fine particles that flowed out from the heating furnace together with the heating gas were recovered by a cyclone. The recovered powder was a pale ocher fine powder (Example 23).

(Powder X-ray analysis result)
Diffraction lines of free CaO and calcite (Calcite): CaCO ₃ and quartz (Quartz): SiO _{2 before thermal decomposition were confirmed.} Since the heating time is extremely short, Tokunoshima lime is not completely decomposed, and the reaction between _{CaO and SiO 2 is insufficient.}

(Mortar test)
A mortar test was carried out on a rotary kiln fired product, a calcined product obtained by fluidized bed firing, and a recovered product obtained by recovering fine particles during fluidized bed firing with a cyclone. Before mixing with the fine aggregate, the rotary kiln calcined product and the fluidized bed calcined product containing agglomerated grains were crushed and pulverized using a mortar.
The fine aggregate used in the mortar test was 0.18 to 0.85 mm shirasu powder obtained by classifying ordinary shirasu using JIS # 80 and # 20 shirasu.

The above-mentioned three kinds of calcined products or recovered products and Shirasu fine aggregate were mixed at a ratio of 1: 2, and water was added until a paste that could be poured was obtained. In the addition of water, since it contains free CaO, it generates heat and evaporates due to the reaction with water. Therefore, the paste was added little by little while observing the situation, and finally a paste was prepared with a paste mixer (manufactured by JAPAN UNIX). The obtained paste was poured into a plastic mold.

After molding, it is stored for 2 days in an environment of 90% or more humidity, then removed from the mold soaked in water for 28 days, left at room temperature for 1 week to dry, and then Shimadzu Autograph (AG-10TA) strength measuring machine. The compressive strength was measured at.
As Comparative Example 9, a mortar was prepared in the same manner as in Comparative Example 7 by using a calcined product obtained by heating Tokunoshima lime at 900 ° C. for 1 hour and decomposing (CaCO ₃ → CaO + CO _{2) as the calcined product.} The X-ray diffraction pattern of the fired product of Comparative Example 9 is shown in FIG.
Table 11 shows the results of the compressive strengths of Examples 21 to 23 and Comparative Example 9.

As can be seen from Table 11, Examples 21 to 23 were cured by underwater curing, and their compressive strength was higher than that of calcined lime obtained by heat-decomposing Tokunoshima lime of Comparative Example 9. Further, in Examples 21 to 23, the formation of calcium silicate-based hydrate was confirmed by X-ray diffraction of the compressive strength sample.

In the fired products used in Examples 21 to 23, no clear diffraction line of belite was observed in X-ray diffraction, and the formation of belite, which is a hydraulic substance, was not clear. However, it is in the middle of synthesis, and the fired product is in an activated state. Further, the difference in strength from Comparative Example 9 is the difference in the degree of formation of calcium silicate hydrate by the pozzolan reaction, which is the mechanism of expression of hydraulic hardness, and the calcined product using silas fine powder and Tokunoshima lime as raw materials is active. Therefore, it is considered that the pozzolan reaction proceeded and the bond by calcium silicate hydrate was strengthened.

3, 5, 8, 9 Belt feeder 6 Belt conveyor 4, 19, 23 Sieve 7A-7C Pipeline 10 Air flow classifier 11A-11E Cyclone crusher 12-15, 22, 31, 32 Cyclone classifier 12a, 15a Opening 12b , 15b On-off valve 16, 16A, 16B Bug filter 17A to 17O Pipe line 18, 18B Exhaust blower 20 Rotary feeder 21 Specific gravity difference sorting device 21a Perforated plate 21b Blower fan 21c, 21d, 21f, 21e Outlet 21g Vibrating device 21h A Coarse grain B1 Fine grain sieve (pumice stone)
B2 Under a fine-grained sieve (volcanic glass)
C Fine powder D Relative density E1 Sieve (light density)
Under E2 sieve (light density and / or volcanic glass)
F Fine powder G, H, I Intake J Exhaust

Claims (13)

It is characterized by using lime and fine powder of volcanic glass material with a particle size of less than 0.05 mm separated from volcanic ejecta deposit minerals with a particle size of 5 mm or less, including volcanic glass material, as raw materials and firing at 900 to 1150 ° C. A method for producing hydraulic lime. The method for producing hydraulic lime according to claim 1, wherein the volcanic ejecta deposit mineral containing the volcanic glass material and having a particle size of 5 mm or less is usually shirasu. To remove gravel fraction of particle size 5mm greater than the volcano a particle size 5mm following volcanic ejecta deposited minerals containing glass material is transported to a cold or hot air current, at least two cyclones connected to the air flow path for circulating Airflow classification having a cyclone classifier for coarse particle recovery having a classifier, a cyclone classifier for fine particle recovery connected to this cyclone classifier group, and a dust collector for fine powder recovery connected to this cyclone classifier. The device collects coarse particles with a cyclone classifier for coarse particle recovery, fine particles with a cyclone classifier for fine particle recovery, and fine powder with a dust collector for fine powder recovery, and the recovered fine powder is used as the raw material. The method for producing a water-hard lime according to claim 1 or 2. Volcanic ejecta deposit minerals with a particle size of 5 mm or less, including the volcanic glass material , from which gravel with a particle size of more than 5 mm has been removed, are directed toward the porous plate from below while vibrating a porous plate tilted at a predetermined angle from the horizontal direction. It is supplied to an air table type specific gravity difference sorting device that blows air, and is sorted into a heavy specific gravity component, a light specific gravity component, a dust collecting component, and a perforated plate falling component, and the sorted dust collecting component is used as the raw material. The method for producing hydraulic lime according to claim 1 or 2. To remove gravel fraction of particle size 5mm greater than the volcano a particle size 5mm following volcanic ejecta deposited minerals containing glass material is transported to a cold or hot air current, at least two cyclones connected to the air flow path for circulating Airflow classification having a cyclone classifier for coarse particle recovery having a classifier, a cyclone classifier for fine particle recovery connected to this cyclone classifier group, and a dust collector for fine powder recovery connected to this cyclone classifier. With the device, coarse particles are collected by the cyclone classifier group for coarse particle recovery, fine particles are collected by the cyclone classifier for fine particle recovery, and fine powder is collected by the dust collector for fine powder recovery.
The collected coarse particles are supplied to an air table type specific gravity difference sorter that blows air from below toward the perforated plate while vibrating a perforated plate that is tilted at a predetermined angle from the horizontal direction. Sort by specific density, dust collection, and perforated plate drop,
The method for producing hydraulic lime according to claim 1 or 2, wherein the fine powder and the dust collector are used as raw materials. The cyclone classifier of the cyclone classifier group for collecting coarse particles has a conical shape at the upper part, and the hydraulic lime according to claim 3 or 5 is connected to the conduit at the top of the conical shape. Production method. The method for producing hydraulic lime according to claim 3 or 5, wherein the fine powder obtained by further crushing the fine particles is used as the raw material. The amount of the perforated plate dropped by the air table type specific gravity difference sorting device is supplied to the same or another air table type specific gravity difference sorting device having different working conditions, and at least the heavy specific density component and the light specific gravity component are added. , Further sort by dust collection,
The method for producing hydraulic lime according to claim 4 or 5, wherein the selected dust collector is used as the raw material. The light specific density component selected by the air table type specific gravity difference sorting device is supplied to the same or different air table type specific gravity difference sorting device having different working conditions, and at least the heavy specific density component and the light specific gravity component are used. Further sort by the dust collection
The method for producing hydraulic lime according to claim 4 or 5, wherein the selected dust collector is used as the raw material. The dust collector sorted by the air table type specific gravity difference sorting device is supplied to the same or different air table type specific gravity difference sorting device having different working conditions, and at least the heavy specific density component and the light specific gravity component are used. Further sort by the amount of dust collected,
The method for producing hydraulic lime according to claim 4 or 5, wherein the selected dust collector is used as the raw material. The method for producing hydraulic lime according to claim 4 or 5, wherein the particle size of the dust collected is less than 0.05 mm. The method for producing hydraulic lime according to claim 4 or 5, wherein the fine powder obtained by further pulverizing the light specific gravity component is used as the raw material. A method for producing a mortar, which comprises using hydraulic lime obtained by the production method according to any one of claims 1 to 10 as a raw material.

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