JP3210184B2 - Volcanic ash purification method and volcanic ash classification device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for purifying volcanic ash,
The present invention also relates to an apparatus for classifying granules used in this purification method.

[0002]

2. Description of the Related Art In recent years, infrared radiation characteristics of ceramics have been attracting attention.
It is used to assist in growing plants.

[0003] This type of conventional ceramic is manufactured artificially, and is obtained by mixing Al ₂ O ₃ , MnO ₂ , Fe ₂ O _{3 and the} like, and firing this mixture. Alternatively, the calcined product may be pulverized to use the powder, or granules may be generated and used.

[0004]

However, the rougher the surface of the ceramic, the higher its infrared emissivity is,
This is a well-known fact. Therefore, powders and granules are more preferable than fired solids, and the effect is expected to be high.

However, for powders and granules, once fired, the powder is crushed, which is troublesome, and it is difficult to reduce the cost. In addition, the only way to improve the emissivity is to grind finer, so that cost reduction cannot be expected.

Further, in order to form not only powders and granules but also those having a rough surface and various sizes, the manufacturing process is further complicated.

[0007] For these reasons, it is difficult to simultaneously improve the emissivity of infrared rays, reduce costs, and diversify products, and this has hindered the expansion of the infrared radiation characteristics of ceramics.

Accordingly, an object of the first invention is to provide a method of purifying volcanic ash for obtaining various-sized particles from volcanic ash having a high infrared emissivity.

A second object of the present invention is to provide an apparatus for classifying granules of volcanic ash which is most suitable for screening the granules of volcanic ash in accordance with the size in the refining method.

[0010]

Means for Solving the Problems In order to solve the above problems, in the method for purifying volcanic ash of the first invention, a heating step of heating the volcanic ash, and after cooling the heated volcanic ash,
A classification step of sequentially passing the volcanic ash through sieves having different eye sizes and classifying the volcanic ash into respective classes having different particle sizes.

Further, volcanic ash is mixed with a solvent,
The mixture containing the volcanic ash is passed through each sieve in the classification process, and each sounding body that generates a sound wave is arranged on each sieve.

[0012] Further, there is provided a washing step of washing the volcanic ash in the liquid tank, and classifying the volcanic ash into respective classes having different particle sizes by utilizing sedimentation of the volcanic ash in the liquid tank. Is for each class classified in the washing process,
The volcanic ash of these classes is heated, and in the classification process, each class classified by each sieve and each class classified in the washing process correspond to each other, and the volcanic ash of each class having the same size of granules is mixed. are doing.

Next, the particle classification apparatus of the second invention comprises a sieve and a sound generator for generating a sound wave having a frequency corresponding to the size of the mesh of the sieve to the sieve.

[0014]

According to the first aspect of the present invention, the volcanic ash is heated in the heating step. By this heating, water, organic matter, sulfur, and the like contained in the volcanic ash are removed, and the volcanic ash is easily separated into particles of various sizes. In the subsequent classification step, the volcanic ash is sequentially passed through sieves having different eye sizes, and the volcanic ash is classified into respective classes having different particle sizes. The granules thus refined do not destroy the porosity peculiar to volcanic ash and have a rough surface. Therefore, even if the particles are very fine, they have a high infrared emissivity.

Further, volcanic ash is mixed with a solvent,
The mixture containing the volcanic ash is passed through each sieve in the classification process, and each sounding body that generates a sound wave is arranged on each sieve. This sound wave activates the granules of the volcanic ash mixed in the solvent, and the granules quickly pass through the sieve.

Further, a washing step may be provided. In this case, the volcanic ash is washed in the liquid tank, and the volcanic ash having a different particle size is used by utilizing the precipitation of the volcanic ash in the liquid tank. Classify each class. Accordingly, in the heating step, the volcanic ash of these classes is heated for each class classified in the cleaning step, and in the classification step, each class classified by each sieve and each class classified in the cleaning step Are mixed, and the volcanic ash of each class having the same size of granules is mixed. That is, classification of volcanic ash into each class is performed not only in the classification process but also in the cleaning process, and the volcanic ash of each class in the cleaning process and the volcanic ash of each class in the classification process are mixed between classes having the same size of particles. are doing. Thereby, classification of volcanic ash is performed efficiently.

Next, the particle classification apparatus of the second invention comprises a sieve and a sounding body, and the sounding body generates a sound wave having a frequency corresponding to the size of the mesh of the sieve to the sieve. . This activates the granules of the size passing through the sieve, as described above, and the granules of this size pass through the sieve quickly.

[0018]

Embodiments of the present invention will be described below with reference to the accompanying drawings. Here, since one embodiment of the particle classification apparatus of the second invention is applied to one embodiment of the method of purifying volcanic ash of the first invention, these purification methods and the classification apparatus will be described together.

Since the refining method of this embodiment uses a plurality of sieves having different mesh sizes, the specifications of these sieves are shown in the following table.

[0020]

[Table 1]

In the purification method of this embodiment, the following steps are sequentially performed.

[Sampling process] At the site near the volcano, volcanic ash was collected from No. 1 in the above table. The mixture is passed through a sieve of No. 4 to collect granules smaller than φ5 mm. This collected material is referred to as raw material ash.

[First Cleaning Step] The raw material ash is put into a first water tank 1 as shown in FIG. 1 and stirred. This first tank 1
A water level gauge 2, a water temperature gauge 3, an optical sensor 4 for confirming sediment, and a drain cock 5 are provided.

The water temperature of the first water tank 1 is measured by a water temperature gauge 3 and is always kept at 25.degree. This is for keeping the rate of precipitation of the raw material ash in the water tank constant, and is necessary for repeatedly reproducing the same precipitation state.

After waiting for about one hour from the charging and stirring of the raw ash, impurities such as dead leaves, wood chips and small animal droppings contained in the raw ash float in the upper layer. The water in the upper layer is drained, and the impurities are discarded. .

Thereafter, the water in the first water tank 1 is stirred again.
When a certain time (for example, one minute) has elapsed and the presence of the sediment is detected by the optical sensor 4, the drain cock 5 is opened for a short time to collect the sediment at the bottom of the first water tank 1. . Since this precipitate was deposited in one minute, the diameter of the granules was large, and coarse gravel and small gravel of φ250 μm to φ5 mm. 16,
Identical to those collected by each of the 60 sieves.

After collecting the coarse gravel and small gravel of φ250 μm to φ5 mm, the drain cock 5 is temporarily closed. At this time, the particles remaining in the first water tank 1 have a diameter of φ250.
It is less than μm. Then, the drain cock 5 is opened again, and the water in the first water tank 1 is transferred to the second water tank 6 as shown in FIG.

Therefore, here, the raw ash is φ250
μm ~ φ5mm coarse gravel and small gravel, and classified into granules less than φ250μm, the former coarse gravel and small gravel are collected,
The latter granules are transferred to the second water tank 6 together with water.

[Second Washing Step] The water in the first water tank 1 is
After being transferred to the second water tank 6 shown in FIG.

As in the first water tank 1, the second water tank 6 is provided with a water level gauge 7, a water temperature gauge 8, an optical sensor 9 for confirming sediment, and a drain cock 11. An optical sensor 12 for detecting is provided.

The temperature of the water in the second water tank 6 is also maintained at 25 ° C., so that the sedimentation rate of the particles in the water tank is kept constant.

In the second water tank 6, fine sand of φ63 μm to φ250 μm precipitates and accumulates when left for 12 hours, and particles having a diameter of less than 63 μm float in the water of the second water tank 6. The sediment at this time is detected by the optical sensor 9 and the degree of contamination is detected by the optical sensor 12. After confirming the detection by these optical sensors, the drain cock 11 is opened for a short time, and the sediment is removed. Collect the fine sand that is the object.

The fine sand has a diameter of φ63 μm to φ250.
μm, the No. in the above table. The same as that collected by the 235 sieve.

Immediately after collecting the fine sand of φ63 μm to φ250 μm, the drain cock 11 is closed once and the second
The water in the water tank 6 is left. At this time, the particles remaining in the second water tank 6 are smaller than φ63 μm. Then, the drain cock 11 is opened again, and the water in the second water tank 6 is transferred to the third water tank.

Therefore, here, φ63 μm to φ2
Classified into fine sand of 50 μm and granules of less than φ63 μm,
The former fine sand is collected, and the latter granules are transferred to a third water tank.

[Third Cleaning Step] The third water tank has the same configuration as the second water tank 6 shown in FIG. 2, and its water temperature is maintained at 25 ° C.

In the third water tank, the water in the second water tank 6 is left for 72 hours after the water is transferred. By leaving for 72 hours, silt and clay having a diameter of less than 63 μm precipitate and deposit. The accumulated silt and clay, and the degree of contamination are detected by the respective optical sensors. After confirming these, the drain cock is opened for a short time,
Collect silt and clay.

If the silt and clay having a diameter of less than 63 μm are collected, the water in the third water tank is discarded.

The deposited silt and clay having a diameter of less than 63 μm are designated as Nos. The same as that classified by the 440 sieve.

[Heating Step] Coarse and small gravel of φ250 μm to φ5 mm classified in [First cleaning step], [Second cleaning step] and [Third cleaning step], Fine sand of φ63 μm to φ250 μm, φ63 μm
Less silt and clay are each separately heat treated.

This heat treatment is performed by an electric furnace.
In a furnace at 550 ° C., 20 kg is heated for 2 hours. After that, it is taken out of the electric furnace and placed in a drying room for 24 hours
Allow time for natural cooling.

By this heat treatment, coarse gravel, small gravel,
Moisture is removed from fine sand, silt and clay particles,
The impurities burn. Removal of water and burning of impurities
Weaken the connection of multiple finer particles that make up the particles,
These particles are easily decomposed. That is, a plurality of finer granules constituting the granules are linked by a crosslinked structure, but the crosslinked structure is easily broken by removing moisture and impurities.

[First Classification Step] The coarse gravel and small gravel of φ250 μm to φ5 mm which have been classified in the [first cleaning step] and heated in the [heating step] are shown in FIG.
The hopper 21 according to the second embodiment of the present invention as shown in FIG.

The hopper 21 is of a funnel type, and has a No. 16 sieves (reference numeral 22)
), And this opening is closed by the lid 23.

On the back surface of the lid 23, a total of 12 ultrasonic transducers 24 are provided. The ultrasonic oscillator 25
An ultrasonic signal is oscillated, and the ultrasonic signal is applied to each ultrasonic transducer 24. These ultrasonic transducers 24 emit ultrasonic waves downward, that is, toward the sieve 22. The frequency of the ultrasonic waves emitted from these ultrasonic vibrators 24 is 28 KHz, and the power consumption of these ultrasonic vibrators 24 is 600 W.

A sediment discharge hole 26 is provided at the bottom of the hopper 21, and the discharge hole 26 is opened and closed by a drain cock 27. A solvent discharge hole 28 is also provided on a side wall of the hopper 21, and the discharge hole 28 is opened and closed by a drain cock 29.

A heat absorbing tube 31 is provided around the outer periphery of the hopper 21.
Are arranged. Refrigerant from the cooling compressor 32 is fed into the heat absorbing tube 31, and the refrigerant flows from the heat absorbing tube 31 to a radiating tube (not shown) and is returned to the cooling compressor 32. Thereby, the hopper 21 is cooled.

The hopper 21 has a diameter of 60 cm and a height of 5 cm.
At a size of 0 cm, 180 liters of a solvent (hydrocarbon, aromatic) is stored inside. In order to detect the liquid level, liquid temperature, and the degree of contamination of the solvent, the hopper 21 has a liquid level meter 33, a liquid temperature meter 34, an optical sensor 3
5 are provided. The hopper 21 is also provided with an optical sensor 36 for confirming the sediment.

Here, the solvent is stored in the hopper 21 and
No. After arranging the 16 sieves 22, the coarse gravel and small gravel of φ250 μm to φ5 mm described above are
Input only Kg. Thereby, 5 kg of coarse gravel and small gravel are mixed into the solvent in the sieve 22.

Thereafter, the lid 23 is closed and the ultrasonic oscillator 25
To drive each ultrasonic transducer 24 on the back surface of the lid 23. The sound waves from the ultrasonic vibrator 24 vibrate the coarse gravel and the small gravel mixed in the solvent, and the vibrations promote the coarse gravel and the small gravel contained in the coarse gravel and the small gravel. And deposits on the bottom of the hopper 21.

Here, the frequency of the sound wave from each ultrasonic transducer 24 is 28 KHz as described above. The frequency of 28 KHz is determined according to the mesh diameter of the sieve 22 of φ1 mm, and efficiently stimulates particles having a size close to the φ1 mm. This makes it easier for particles less than φ1 mm contained in the coarse and small gravel to pass through the screen of the sieve 22.

Since the bonding of a plurality of finer granules constituting the granules is weakened by the above-mentioned heat treatment, the coarse gravel and the small gravel in the sieve 22 are stimulated by the sound wave. And it is broken down finely. As a result, particles having a diameter of less than φ1 mm are newly generated, and the new particles also pass through the screen of the sieve 22 and deposit on the bottom of the hopper 21.

The φ1 deposited on the bottom of the hopper 21
Particles smaller than mm are taken out by opening the drain cock 27 of the sediment discharge hole 26 of the hopper 21. In addition, sieve 2
The coarse gravel of φ1 mm to φ5 mm remaining in
Collected from 2.

Therefore, here, φ1 mm to φ5 m
m coarse gravel and granules of less than φ1 mm. The former coarse gravel is collected, and the latter granules are transferred to the [second classification step] following this [first classification step].

On the other hand, the temperature of the solvent in the hopper 21 rises due to the energy of the sound wave from each ultrasonic transducer 24, and it is necessary to keep this temperature below the ignition temperature of the solvent. Therefore, when the temperature of the solvent approaches the ignition temperature while checking the temperature of the solvent by the liquid thermometer 34 of the hopper 21, the cooling compressor 32 is operated to connect the heat absorbing pipe 31 on the outer periphery of the hopper 21. Pump the refrigerant,
The hopper 21 is cooled to lower the temperature of the solvent.

The temperature of the solvent depends on the kind of the solvent, but is kept at, for example, 25 ° C., which is lower than the ignition temperature, thereby avoiding danger.

[Second Classification Step] Here, the same hopper as in [First Classification Step] is used.
No. Sixty sieves are placed in the hopper.

In this [second classification step], the [first classification]
Classification step] is less than 5 kg
No. No. 60 sieve. In a sieve of 60, φ1
Particles smaller than mm are mixed in the solvent.

Thereafter, the lid is closed, and each ultrasonic vibrator is driven to emit ultrasonic waves. Thereby, φ250μm
No. less than No. It settles through 60 sieves and accumulates at the bottom of the hopper.

At this time, in the same manner as in the [first classification step], No. 1 Particles having a size close to the diameter of φ250 μm of the 60 sieves are efficiently stimulated, and particles having a diameter of less than φ250 μm easily pass through the sieves. Also, the particles in the sieve
Decomposes finely under the stimulus of sound waves. As a result, φ
Granules smaller than 250 μm are newly formed and pass through the sieve.

The φ250 thus deposited on the bottom of the hopper
The granules having a particle diameter of less than μm are taken out by opening a drain cock of a sediment discharge hole, and the particles remaining in the sieve are φ250 μm to φ1 μm.
mm gravel is taken from this sieve.

Therefore, here, φ250 μm to φ250 μm
Classified into small gravel of 1 mm and granules of less than φ250 μm. The former small gravel is collected, and the latter granules are transferred to the [third classification step] following this [second classification step].

[Third Classification Step] The hopper is the same as that described above. 235 sieves are applied, and the frequency of ultrasonic waves emitted from each ultrasonic transducer on the back surface of the lid is set as high as 40 KHz.

In this [third classification step], 2
The fine sand obtained in the [second washing step] and the granules having a diameter of less than φ250 µm obtained in the [second classification step] are put into a sieve of No. 35, and only 5 kg is charged.

Thereafter, the lid is closed, and each ultrasonic vibrator is driven to emit an ultrasonic wave having a frequency of 40 KHz. The frequency of 40 KHz of this ultrasonic wave is No. 235 sieve mesh diameter φ
It is determined according to 63 μm. As a result, φ63
Particles smaller than μm are no. Precipitates quickly through 235 sieve eyes and deposits at the bottom of the hopper. Further, the granules in the sieve are finely decomposed, and granules having a diameter of less than φ63 μm are newly generated and pass through the sieve.

The φ63μ thus deposited on the bottom of the hopper
The granules having a particle diameter of less than m are taken out by opening the drain cock of the sediment discharge hole, and the particles remaining in the sieve are φ63 μm to φ250.
μm fine sand is collected from this sieve.

As a result, fine sand of φ63 μm to φ250 μm is collected, and the particles having a diameter of less than φ63 μm are transferred to the subsequent [fourth classification step].

[Fourth Classification Step] In this case, No. in the above table was used as a sieve. 440 is applied, and the frequency of the ultrasonic wave emitted from each ultrasonic transducer is set to 40 KHz.

In this [fourth classification step], No. 4
The silt and clay obtained in the [third washing step] and the granules having a diameter of less than 63 µm obtained in the [third classification step] are put into a sieve 40 together.

Thereafter, the lid is closed, and each ultrasonic transducer is driven to emit an ultrasonic wave having a frequency of 40 KHz. As a result, clay having a diameter of less than φ32 μm was no. Precipitate through 440 sieve immediately. Also, φ32 μm to φ63 μm
Of silt are left in the sieve. This φ32μm ~ φ63μ
The m silt is collected by opening the drain cock of the sediment discharge hole, and the clay having a diameter of less than φ32 μm is collected from the sieve.

[Drying process] Thus, by the [first classification process] to [fourth classification process], coarse gravel, small gravel, fine sand, silt, and clay divided into five classes are classified into each class. Then, it is taken into a drying room and left to stand, where it is naturally dried and the solvent is removed.

Thus, the purification method of this embodiment is completed.

As described above, in the above embodiment, the volcanic ash is no.
The raw material ash having a diameter of 5 mm or less is collected through a sieve of No. 4, and the raw material ash is washed, and then heated. By this heating, the crosslinked structure of the particles such as gravel and clay is easily broken, and the particles are easily decomposed into a plurality of finer particles. For this reason, when sieved, the granules are broken down into a plurality of finer granules, and the amount of finer silt or clay collected is increased.

According to this refining method, the granules are decomposed without exerting an excessive force on the large and small granules, so that regardless of the size of the granules, the porous material peculiar to volcanic ash is not lost. I'm done. For this reason, the surface of the granules is coarse and the infrared emissivity is high regardless of coarse gravel, small gravel, fine sand, silt, or clay.

On the other hand, the conventional ceramic powder is not porous, so that the infrared emissivity cannot be increased unless it is finely crushed. Also, coarse gravel,
It is very difficult to produce various sizes of granules from ceramic powders as with small gravel, clay granules and the like.

Further, it is possible to break down or crush the volcanic ash with a rotary blade or a roller to obtain granules. However, in such a method, the porosity of the volcanic ash is also destroyed. The same effect as the invention cannot be expected.

Further, in this embodiment, in each classification step, not only classification into coarse gravel, small gravel, etc., but also classification in each washing step, and the granules classified in the washing step are subjected to the classification of the granules. Since it is assigned to an appropriate classification process according to the size,
Efficient classification is possible.

By the way, coarse gravel, small gravel, fine sand, silt, and clay obtained according to this embodiment are properly used depending on the size. For example, coarse gravel is mixed into the soil of rice fields and fields and used to assist in growing crops. Also, small gravel, fine sand, and the like are mixed into the sand of the sand bath or mixed with the material of the inner wall of the building for heat retention.
Further, the clay is mixed with the synthetic resin, stretched into a sheet shape, cut into an appropriate size, and attached to the body.

In the above embodiment, the volcanic ash was converted to coarse gravel,
Although it is divided into five classes, small gravel, fine sand, silt, and clay, the number of classes may be increased or decreased. Also, other types of liquids than water can be used to clean the volcanic ash. Alternatively, the temperature, time, hopper, and the like in this embodiment may be appropriately changed.

[0080]

As described above, according to the refining method of the first invention, the volcanic ash is heated to remove water, organic matter, sulfur and the like contained in the volcanic ash, and the granules of the volcanic ash are further finely divided. It is easy to decompose into multiple particles. And
The volcanic ash is sequentially sieved through sieves having different eye sizes, and the volcanic ash is classified into respective classes having different grain sizes. Thereby, granules of various sizes can be obtained while maintaining the surface roughness without destroying the porosity peculiar to the volcanic ash.

In the classifier according to the second aspect of the invention, a sound wave having a frequency corresponding to the size of the mesh of the sieve is generated for the sieve to vibrate particles having a size passing through the mesh of the sieve. Thus, the granules pass through the sieve immediately.

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing a first water tank used in an embodiment of the purification method of the first invention.

FIG. 2 is a diagram schematically showing a second water tank used in one embodiment of the purification method of the first invention.

FIG. 3 is a diagram schematically showing an embodiment of a classification device according to the second invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st water tank 2,7 Water level gauge 3,8 Water temperature meter 4,9,12,35,36 Optical sensor 5,11,27,29 Drain cock 6 2nd water tank 21 Hopper 22 Sieve 23 Cover 24 Ultrasonic transducer 25 Ultrasonic oscillator 26 Precipitate discharge hole 28 Solvent discharge hole 31 Endothermic tube 32 Cooling compressor 33 Liquid level meter 34 Liquid temperature meter

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B03B 5/00 B07B 1/00-1/62

Claims (2)

(57) [Claims] 1. The method of claim 1 wherein heating the volcanic ash removes moisture.
And originating removed and to combustion dividing removed by the impurity, hydrocarbon soluble in the sieve
A method for purifying volcanic ash, which comprises applying acoustic waves to the cooled volcanic ash mixed with an agent or an aromatic solvent to further refine the granulated ash and passing through a sieve. 2. A sieve is provided at an opening of a funnel-type hopper storing a hydrocarbon solvent or an aromatic solvent, and sonic vibration is applied to the cooled volcanic ash mixed with the solvent in the sieve.
A classifier for volcanic ash, wherein a sounding body is provided and provided, and a sediment discharge hole that can be opened and closed is provided at the bottom of the hopper.