JP6781426B1 - Granular acid soil correction agent using shell powder and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a granular acid soil corrective agent granulated to such an extent that it does not easily scatter even when shell powder is used as a main raw material, and a method for producing the same. SOLUTION: The granular acid soil corrective agent has a bulk density in the range of 0.5 g / ml to 1.3 g / ml or an angle of repose in the range of 55 ° to 80 ° after the completion of the tapping treatment. It contains a classified shell powder and a binder that agglomerates the classified shell powder. The particle size of each granule of the granular acid soil correction agent is in the range of about 1 mm to about 30 mm. The shell powder may be a powder obtained by crushing scallop shells, and the binder may be a molasses solution. [Selection diagram] Fig. 1

Description

The present invention relates to a granular acid soil corrective agent using shell powder and a method for producing the same.

Acid soil correction agents for improving acidic soil are known. The acid soil corrector contains calcium carbonate as a main component and is used to correct the pH (Potential of Hydrogen) of acidic soil. Since the main component of shells is calcium carbonate and can be obtained at a lower cost than lime, which also contains calcium carbonate as the main component, a powdered acid soil corrector using shells has been put into practical use. For example, Patent Document 1 discloses a soil conditioner (acid soil corrector) containing shell powder such as scallops, oysters, and freshwater clams.

Japanese Unexamined Patent Publication No. 2004-300237

In the acid soil correction agent of Patent Document 1, since the shell is powdered, even if it is sprayed on the soil, it is easily scattered to other places due to the influence of wind and the like, and it is difficult to efficiently spray it on the soil. There's a problem. Therefore, it is conceivable to granulate the shell powder to the extent that it does not easily scatter due to the influence of wind or the like. However, since the shell is a naturally derived material, it is not possible to obtain a uniform powder suitable for granulation, and it has been technically difficult to granulate the shell powder.

The present invention has been made based on such a background, and provides a granular acid soil corrective agent granulated to such an extent that it does not easily scatter even when shell powder is used as a main raw material, and a method for producing the same. The purpose is to do.

In order to achieve the above object, the granular acid soil corrective agent according to the first aspect of the present invention is
It is a shell powder obtained by crushing a shell, and the bulk density after the tapping treatment is in the range of 0.5 g / ml to 1.3 g / ml, or the angle of repose is in the range of 55 ° to 80 °. A granular acid soil corrective agent containing a seashell powder classified as described above and a binder for aggregating the classified seashell powder.
The particle size of each granulated body of the granular acid soil corrector is in the range of 1 mm to 30 mm.

Shell powder is crushed scallop shell powder.
The binder may be molasses.

The water content of each granule may be in the range of 1.0% to 7.5% on a dry basis.

In order to achieve the above object, the method for producing a granular acid soil corrective agent according to the second aspect of the present invention is
From the shell powder obtained by crushing the shell, the bulk density after the tapping treatment is in the range of 0.5 g / ml to 1.3 g / ml, or the angle of repose is in the range of 55 ° to 80 °. And the classification process to classify
A granulation step of adding a binder to the shell powder classified in the classification step and rolling the shell powder in a rotating container to form a granule from the shell powder.
A drying step of drying the granules formed in the granulation step and
including.

Shell powder is crushed scallop shell powder.
The binder may be molasses.

The molasses liquid may have a density of 1.175 g / cm ³ or more, or a solid component amount of 40 g / 100 ml or more.

In the classification step, the shell powder may be classified by passing the crushed shell powder through a fine sieve of 100 mesh or more, or by sieving by wind classification.

The water content of the mixture of the shell powder and the binder in the granulation step is 23.1 vol. % ~ 28.6 vol. It may be in the range of%.

In the drying step, the granulated material may be dried so as to reduce the water content of the granulated material formed in the granulated step to a range of 1.0% to 7.5% based on the dry amount. ..

According to the present invention, it is possible to provide a granular acid soil corrective agent granulated to such an extent that it does not easily scatter even when shell powder is used as a main raw material, and a method for producing the same.

It is a figure which shows the structure of the rolling granulator which concerns on embodiment of this invention. It is a flowchart which shows the flow of the manufacturing method of the granular acid soil correction agent which concerns on embodiment of this invention. (A) is a graph showing the particle size distribution of the pulverized powder obtained by the wind power classification in Example 1, and (b) is a diagram showing an SEM (Scanning Electron Microscope) image of the wind power classification powder in Example 1. .. (A) to (d) are diagrams showing the results of rolling granulation using scallop shell powder satisfying each condition in Example 1. It is a graph which shows the relationship between the solid component amount and density of the molasses liquid in Example 2. FIG. (A) to (c) are diagrams showing the results of rolling granulation using a molasses solution satisfying each condition in Example 2. (A) to (g) are diagrams showing the results of rolling granulation using a mixture of a raw material powder and a binder having each water content in Example 3. It is a graph which shows the particle size distribution of the granules at each rotation speed in Example 4. It is sectional drawing which shows the structure of the load test apparatus in Example 5. It is a graph which shows the relationship between the crushing rate of the granulated material in Example 5 and the water content based on the dry amount. It is a graph which shows the relationship between the moisture content of the dry amount standard in Example 6 and a drying time. It is a graph which showed the time-dependent change of the pH value in the surface layer of the volcanic ash soil and the inside 30 cm in Example 7. 6 is a graph showing the effect of the amount of lignin added in Example 8 on the particle size distribution of the granules. (A) to (e) are graphs showing the results of performing a load-bearing test on a single granule in Example 8. It is a figure which shows the crushing rate of the granulated material at the time of carrying out the load load test on the individual granule, and the particle layer in Example 8, respectively.

Hereinafter, embodiments of the granular acid soil corrective agent according to the present invention will be described in detail with reference to the drawings. In each drawing, the same or equivalent parts are designated by the same reference numerals.

The granular acid soil correction agent is a granular acid soil correction agent produced by agglutinating shell powder. The granular acid soil corrective agent is a granulated material produced by using a known granulation method, for example, a rolling granulation method. In the rolling granulation method, the raw material powder is put into a granulating container such as a rotating bread, and then water or a binder is added to the raw material powder, so that the particles that make up the raw material powder are compacted to achieve granulation. proceed. The granulated material granulated by the rolling granulation method has a smooth surface and has a spherical shape or a shape similar thereto. Immediately after granulation, the granulated material is somewhat moist due to the addition of water or a binder, and is easily crushed, but the granulated material can be made stronger by drying.

FIG. 1 is a diagram showing a configuration of a rolling granulator 10 according to an embodiment. The rolling granulator 10 is a device that performs rolling granulation by rolling a raw material powder in which water or a binder is added to the raw material powder. The rolling granulator 10 includes a pan 11, a motor 12, a rotating shaft 13, and an inclination adjusting mechanism 14.

The pan 11 is a container for containing the raw material powder inside, and rolls the raw material powder in accordance with the rotation of the motor 12. The pan 11 is rotatably installed in a state of being inclined with respect to the horizontal plane. The diameter of the pan 11 is, for example, about 100 cm to 300 cm.

The motor 12 is connected to the pan 11 via a rotation shaft 13 and rotates the pan 11 at a predetermined rotation speed around the rotation axis shown by the one-point chain line in FIG. The rotation speed of the pan 11 affects the particle size distribution of the granulated material to be granulated. The rotation speed of the pan 11 is set in consideration of the particle size of the raw material powder, the density of the binder, the inner diameter and inclination of the pan 11, the temperature and humidity of the environment in which the rolling granulator 10 is installed, and the like.

The larger the diameter of the pan 11, the smaller the optimum rotation speed for granulating the raw material powder. If the diameter of the pan 11 is about 30 cm, the rotation speed of the pan 11 is, for example, in the range of 20 rpm to 40 rpm, and if the diameter of the pan 11 is about 300 cm, the rotation speed of the pan 11 is, for example, 1 rpm. It is in the range of ~ 30 rpm.

The rotation shaft 13 is connected to the pan 11 and the motor 12, and transmits the rotation of the motor 12 to the pan 11. The tilt adjusting mechanism 14 rotatably supports the motor 12 that supports the pan 11 so that the tilt angle of the pan 11 can be adjusted. The inclination angle of the pan 11 is the angle formed by the bottom surface of the pan 11 and the horizontal plane, and is the particle size of the raw material powder, the density of the binder, the inner diameter and rotation speed of the pan 11, and the environment in which the rolling granulator 10 is installed. It is set in consideration of temperature, humidity, etc. If the diameter of the pan 11 is about 30 cm, the inclination angle of the pan 11 is about 60 °.
The above is the configuration of the rolling granulator 10.

The raw material powder is obtained from a powder (crushed powder) obtained by crushing shells with a mill or the like. The shell is a shell containing calcium carbonate as a main component, for example, a shell such as scallop, oyster, clam, clam, clam, etc., and is preferably a scallop shell. The pulverized powder contains particles and debris of various sizes, and has a wide variety of shapes, from elongated debris to granular ones.

A raw material powder (classified powder) can be obtained by classifying the above-mentioned pulverized powder. The classified powder that enables granulation is specified by the maximum particle size, bulk density, and angle of repose. Since the maximum particle size, bulk density and angle of repose correlate with each other, one of the parameters may be specified to specify the classified powder that enables granulation. The bulk density is an index for evaluating the fineness of powder, and is calculated by dividing the volume of the container containing the powder by the weight of the powder contained in the container. The angle of repose is an index for evaluating the ease of sticking of powders to each other and the fluidity, and is indicated by the angle between the slope of a mountain of conical powder formed by dropping the powder on a flat plate and the horizontal plane. The bulk density in the embodiment is not the bulk density of the powder naturally accumulated in the container, but the bulk density after tapping the powder contained in the container.

To enable granulation of shell powder, the maximum particle size of the classified powder is about 149 μm or less, its bulk density is 1.3 g / ml or less, or its angle of repose is 55 °. The above is sufficient. Considering the classification operation of the crushed powder, in reality, the bulk density of the classified powder is in the range of 0.5 g / ml to 1.3 g / ml, or the angle of repose is in the range of 55 ° to 80 °. Is preferable. Furthermore, the angle of repose of the classified powder is more preferably in the range of 60 ° to 80 °. As long as the shell powder satisfies this condition, even if the particles of the shell powder include particles and fragments of various sizes and have a wide variety of shapes from elongated debris to granular ones, the rolling structure of the shell powder Grains are possible.

The classification powder satisfying the above conditions can be obtained by sieving using a fine sieve of 100 mesh or more, or by performing wind power classification. The 100-mesh sieve has 100 wires between 1 inch (25.4 mm) and a spacing (opening) between the wires of 149 μm. Further, wind power classification is a method of classifying pulverized powder by applying centrifugal force to the powder by rotating a rotor or the like.

The binder is also called a granulation promoting material, and is a material that promotes the aggregation of the raw material powder when the raw material powder is granulated. The binder plays an important role in agglomeration of particles by wetting the surface of the raw material powder in rolling granulation. The binder is preferably molasses, but other binders such as lignin sulfonic acid (lignin), starch, konjac flour and the like may be used. The molasses liquid is a dark brown liquid that is generated when sugar is produced from sugar cane, sugar beet, etc., and contains, for example, about 40% to 60% sugar, inorganic substances, organic substances such as crude proteins, and the like.

The characteristics of the molasses liquid that can be granulated can be specified by any one of the density, the amount of solid components, and the content of molasses. The density of the molasses liquid that can be granulated is about 1.175 g / cm ³ or more, the amount of solid components thereof is about 40 g / 100 ml or more, and the molasses content is about 8.7 wt. % Or more. In order to obtain granules having a uniform particle size, the density of the molasses solution is in the range of about 1.175 g / cm ³ to about 1.250 g / cm ³ , or the amount of solid components of the molasses solution is about. The molasses content in the range of 40 g / 100 ml to about 65 g / 100 ml or in the molasses liquid is about 8.7 wt. % ~ Approximately 13.4 wt. It is preferably set within the range of%.

The particle size of the granules is set according to the standards specified by the agricultural cooperatives in each region. The particle size of the granules is preferably as uniform as possible because it affects the duration of the pH correction action in the soil. The particle size of the granules is such that they do not scatter even when sprayed on soil, for example, in the range of about 1 mm to about 30 mm, preferably in the range of about 1 mm to about 10 mm. Within, more preferably in the range of about 1 mm to about 5 mm, and even more preferably in the range of 2 mm to 4 mm.

Since each granulated body constituting the granular acid soil corrective agent has a certain size as described above, not only is there no risk of scattering due to wind or the like, but also compared to the powder acid soil corrective agent. The acidity correction ability is maintained. Therefore, the frequency of spraying the granular acid soil correction agent on the acidic soil can be suppressed.

The water content of the classified powder before granulation is set so that the classified powder can be granulated. The water content of the classified powder that can be granulated is about 23.1 vol. % Or more, but in order to produce granules having a uniform particle size, about 23.1 vol. % ~ About 28.6 vol. It is preferable to set it within the range of%. The water content of the classification powder can be adjusted by adjusting the amount of binder or water added to the classification powder.

The water content of the granulated material after granulation is set so that the granulated material will not be crushed even if the bags filled with the granulated material are stacked and stored in a warehouse or the like. The water content is adjusted by adjusting the drying time and the drying temperature of the granulated material produced by rolling granulation. The water content of the granulated product is about 7.5% or less based on the dry amount, preferably about 5.0% or less, but considering the range that can be realistically achieved in the drying step, for example. The dry amount is in the range of about 1.0% to about 7.5%, preferably in the range of about 1.0% to about 5.0%.

Next, with reference to the flowchart of FIG. 2, an example of a method for producing a granular acid soil corrective agent performed by using the rolling granulator 10 according to the embodiment will be described. First, the shell is crushed into powder using a crusher such as a roller mill (step S1).

Next, the pulverized powder crushed in step S1 is classified to obtain a classified powder (step S2). Specifically, the crushed crushed powder is passed through a 100-mesh sieve, or the crushed crushed powder is subjected to wind power classification to obtain a classified powder suitable for granulation.

Next, the pan 11 is rotated at a predetermined rotation speed by operating the motor 12 of the rolling granulator 10 (step S3). For example, when the diameter of the pan 11 is 30 cm and the inclination angle of the pan 11 is 60 °, the rotation speed may be set to 20 rpm in order to keep the particle size of the granulated material within the range of 1 mm to 4 mm.

Next, the classified powder classified in step S2 is put into the pan 11 rotated in step S3 (step S4).

Next, a binder is added to the classified powder in the pan 11 charged in step S4 by a method such as spraying (step S5). As the binder, for example, molasses liquid is suitable. In step S5, the binder may be added little by little to the classified powder, for example, in the same amount at predetermined intervals, or may be added all at once.

Next, it is determined in step S5 whether or not the granulation of the classified powder is completed by rolling the classified powder to which the binder is added (step S6). The guideline for the rolling time of the classified powder is, for example, in the range of about 5 minutes to about 30 minutes.

When the granulation of the classified powder is completed (step S6; Yes), the rotation of the pan 11 is stopped (step S7). On the other hand, when the granulation of the classified powder is not completed (step S6; No), the rotation of the pan 11 is continued.

After the treatment in step S7 is completed, the granules formed from the classified powder are taken out from the pan 11 and dried until the optimum water content is reached (step S8), and the treatment is completed. The drying method may be natural drying or air supply drying. In the case of air supply drying using a drying device, for example, the air supply temperature from the drying device may be set in the range of about 40 ° C. to about 90 ° C. Moreover, the drying time may be in the range of about 30 minutes to about 90 minutes.
The above is the flow of the manufacturing method of the granular acid soil corrective agent by the batch operation.

As described above, the granular acid soil corrective agent according to the embodiment has a bulk density in the range of 0.5 g / ml to 1.3 g / ml or an angle of repose in the range of 55 ° to 80 °. It is a granular acid soil correction agent containing the shell powder classified as described above and a binder for aggregating the classified shell powder, and the particle size of each granulated body of the granular acid soil correction agent is about 1 mm to about. It is within the range of 30 mm. Therefore, even a granular acid soil corrective agent using shell powder as a main raw material can be efficiently sprayed on the soil without being easily scattered.

The method for producing the granular acid soil corrective agent according to the embodiment has a bulk density in the range of 0.5 g / ml to 1.3 g / ml or an angle of repose from the shell powder obtained by crushing the shell. A granule is formed from the shell powder by a classification step of classifying the shell powder in the range of 55 ° to 80 ° and by adding a binder to the shell powder classified in the classification step and rolling it in a container. It includes a granulation step and a drying step of drying the granulated material formed in the granulation step. Therefore, even when shell powder is used as the main raw material, it is possible to produce a granular acid soil corrective agent which is granulated to such an extent that it does not easily scatter.

The present invention is not limited to the above embodiment, and the modifications described below are also possible.

(Modification example)
In the above embodiment, the granular acid soil corrective agent is composed of shell powder and a binder, but the present invention is not limited to this. It may contain other substances useful for soil improvement and plant growth, such as phosphoric acid, potassium, magnesium and the like.

In the above embodiment, the conical pan 11 is used as the container of the rolling granulator, but the present invention is not limited to this. For example, the pan 11 may be dish-shaped, cylindrical, or parabolic antenna-shaped. Further, the rolling granulator is not limited to the bread type granulator, and may be, for example, a drum type granulator or a vibration granulator.

In the above embodiment, the shell powder is granulated by using the rolling granulation method, but the present invention is not limited to this. For example, the shell powder may be granulated by using an extrusion granulation method, a fluidized bed granulation method, or the like.

In the above embodiment, the motor 12 is driven to rotate the pan 11 around the rotation axis, and then the classified powder is charged into the pan 11, but the present invention is not limited to this. For example, the classification powder may be put into the pan 11 and then the pan 11 may be rotated. Alternatively, the classification powder may be put into the pan 11 to add a binder, and then the pan 11 may be rotated.

In the above embodiment, the granular acid soil corrective agent is produced from the shell by a batch operation, but the present invention is not limited to this. For example, continuous operation may be adopted in order to efficiently produce a large amount of granular acid soil corrector from shells. In the continuous operation, first, a classification step of classifying the crushed shell powder is executed, then a mixing step of mixing the classification powder and the binder is executed, and then a mixture of the classification powder and the binder is panned 11 A continuous granulation step is executed in which the steps of throwing into the pan 11 are used to granulate the granulated material and the granulated material granulated by the pan 11 is collected, and the granulated material recovered in the continuous granulation step is executed. May include a drying step of drying. In the continuous granulation step, when the granulated material is recovered from the pan 11, a predetermined amount of the mixture mixed in the mixing step may be put into the pan 11.

In the above embodiment, the shell is crushed with a mill or the like and then the crushed powder is classified, but the present invention is not limited to this. For example, you may obtain shells that have been crushed in advance at a fishery processing plant or the like, and then perform a classification operation on the obtained shell powder.

The above-described embodiment is an example, and the present invention is not limited thereto, and various embodiments are possible without departing from the spirit of the invention described in the claims. The components described in each embodiment and modification can be freely combined. The present invention also includes inventions equivalent to those described in the claims.

Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to these examples.

(Example 1)
In Example 1, the conditions of the raw material powder that enables the granulation of the scallop shell powder were investigated by classifying the scallop shell powder under various conditions and attempting to granulate each of them by the rolling granulation method. .. In the rolling granulation of the raw material powder, the shape and size of the raw material powder have a great influence on the propriety of granulation, but the components of the raw material powder do not have a great influence. Therefore, the following experiment was conducted as an example of the case where crushed powder obtained by crushing scallop shells is classified and granulated.

First, the scallop shell was crushed with a mill or the like to obtain a crushed powder containing coarse grains. Then, a part of the pulverized powder was taken out and the pulverized powder was classified under various conditions to obtain a classified powder. The classification of scallop shell powder is either 28 mesh, 48 mesh, or 100 mesh sieving by sieving or wind power classification. The 28-mesh, 48-mesh, and 100-mesh sieves have a mesh size of 590 μm, 297 μm, and 149 μm, respectively, and the powder passed through the sieve has a maximum particle size approximately equal to that of the sieve.

FIG. 3A is a graph showing the particle size distribution of the pulverized powder obtained by the wind power classification in Example 1, and FIG. 3B is a diagram showing an SEM image of the wind power classification powder in Example 1. In the wind-classified powder, the maximum particle size of the powder was about 10 μm as shown in FIG. 3 (a). Further, as can be understood from the SEM image of FIG. 3B, the classified powder also contained particles and debris of various sizes, and the shapes also varied from granular to elongated debris.

For each of the classified powders classified under each condition, the classified powders were placed in a container and tapped, and then the bulk density was measured, and granulation by the rolling granulation method was attempted. For comparison, the bulk density of the crushed powder without classification operation was also measured, and granulation by the rolling granulation method was attempted. Further, the angle of repose was also measured for the pulverized powder without the classification operation, the classification powder using the 28-mesh sieve, and the classification powder using the 100-mesh sieve.

4 (a) to 4 (d) are diagrams showing the results of rolling granulation using scallop shell powder satisfying each condition in Example 1. 4 (a) is a crushed powder containing coarse particles, FIG. 4 (b) is a classification powder by a 28-mesh sieve, FIG. 4 (c) is a classification powder by a 100-mesh sieve, and FIG. 4 (d) is. , It is the result when the wind power classification powder was used respectively.

The pulverized powder containing coarse grains had a bulk density of 1.6 g / ml and an angle of repose of 37 °, and granulation by the rolling granulation method was not possible. In the classified powder by sieving with 28 mesh, the bulk density was 1.4 g / ml, the angle of repose was 51 °, and granulation was impossible. The bulk density of the classified powder by sieving with 48 mesh was 1.4 g / ml, and granulation was not possible. On the other hand, in the classified powder by sieving 100 mesh, the bulk density was 1.3 g / ml, the angle of repose was 60 °, and granulation was possible. Further, in the wind power classification powder, the bulk density was 1.1 μm, and granulation was possible. Therefore, it is understood that the raw material powder that can be granulated by the rolling granulation method is a classification powder obtained by passing crushed scallop shell powder through a fine sieve of 100 mesh or more or performing wind power classification. it can.

(Example 2)
In Example 2, a binder that enables efficient granulation of scallop shell powder by attempting granulation by the rolling granulation method using molasses liquids having different densities, solid component amounts, and molasses contents. I checked the conditions. 126 g of scallop shell powder (volume 100 cm ³ ) was used as a raw material powder, and 30 ml of molasses solution was used as a binder.

FIG. 5 is a graph showing the relationship between the amount of solid components and the density of the molasses liquid in Example 2. The density of the molasses solution and the amount of solid components have a correlation with each other as shown in FIG. Similarly, the amount of solid components in the molasses solution and the content of molasses have a correlation with each other. Therefore, if any one of the density of the molasses liquid, the amount of solid components and the content of molasses is specified, the other two are also specified.

FIG. 6A is a diagram showing the results of rolling granulation using a molasses solution having a density of 1.250 g / cm ³ or more, and FIG. 6B is a diagram showing a density of 1.175 to 1. It is a figure which shows the result of the rolling granulation using the molasses liquid of 250 g / cm ³ , and FIG. 6 (c) shows the rolling granulation which used the molasses liquid of 1.175 g / cm ³ or less in density. It is a figure which shows the result of.

When the density of the molasses liquid was 1.250 g / cm ³ or more (solid component amount 65 g / 100 ml or more, molasses content 13.4 wt.% Or more), the obtained granules were non-uniform in size. .. When the density of the molasses liquid is 1.175 to 1.250 g / cm ³ (solid component amount 40 to 65 g / 100 ml, molasses content 8.7 to 13.4 wt.%), The obtained granules are large. Was uniform. When the density of the molasses liquid was 1.175 g / cm ³ or less (solid component amount 40 g / 100 ml or less, molasses content 8.7 wt.% Or less), sufficient granulation was not performed and a large amount of powder was left. .. From the above, the molasses liquid capable of efficient granulation has a density of 1.175 g / cm ³ or more, a solid component content of 40 g / 100 ml or more, or a molasses content of 8.7 wt. It can be understood that it is% or more.

(Example 3)
In Example 3, the condition of the water content that enables the granulation of the scallop shell powder was investigated by attempting granulation by the rolling granulation method by changing the water content of the mixture of the raw material powder and the binder.

The water content of the mixture of the raw material powder and the binder is 9.1 vol. %, 16.7 vol. %, 20.0 vol. %, 23.1 vol. %, 25.9 vol. %, 28.6 vol. %, 33.3 vol. %. The water content of the mixture of the raw material powder and the binder was adjusted by adjusting the components and amounts of the binder.

7 (a) to 7 (g) are diagrams showing the results of rolling granulation using the mixture of each water content in Example 3. The water content of the mixture was 9.1 vol. In order from FIG. 7 (a) to FIG. 7 (g). %, 16.7 vol. %, 20.0 vol. %, 23.1 vol. %, 25.9 vol. %, 28.6 vol. %, 33.3 vol. %.

The water content of the mixture is 9.1 vol. %, 16.7 vol. %, 20.0 vol. In the case of%, sufficient granulation was not performed and a large amount of powder was left in the bread. On the other hand, the water content of the mixture is 23.1 vol. %, 25.9 vol. %, 28.6 vol. %, 33.3 vol. In the case of%, almost no powder was left in the bread, and sufficient granulation was possible. From the above, the water content of the mixture of the raw material powder and the binder capable of sufficient granulation is 23.1 vol. It can be understood that it is% or more. Considering that the increase in water content reduces the strength of the granules, the water content of the mixture is preferably 23.1 vol. % ~ 28.6 vol. It is in the range of%.

(Example 4)
In Example 4, the rotation speed of the pan 11 of the rolling granulator 10 was changed, and the relationship between the rotation speed of the pan 11 and the particle size distribution of the granulated material was investigated. The rolling granulator 10 has a pan 11 having an inner diameter of 30 cm, and the inclination angle of the pan 11 is 60 °. The rotation speed of the pan 11 was 20 rpm, 30 rpm, and 40 rpm.

FIG. 8 is a graph showing the particle size distribution of the granules at each rotation speed in Example 4. When the rotation speed was 20 rpm, the particle size of the granules was distributed in the range of about 1 mm to about 5 mm. When the rotation speed was 30 rpm, the particle size of the granules was distributed in the range of about 2 mm to about 7 mm. When the rotation speed was 40 rpm, the particle size of the granules was distributed in the range of about 3 mm to about 9 mm. From the above, it can be understood that the particle size of the granulated material increases as the number of rotations of the pan 11 increases.

(Example 5)
In Example 5, in order to obtain the optimum water content of the granulated material after drying, a load test was performed on the granulated material using a load test device.

FIG. 9 is a cross-sectional view showing the configuration of the load test device 20 in the fifth embodiment. The load test device 20 is a device that applies a predetermined load to the granules P arranged in layers. By arranging the granules P in layers and applying a predetermined load, it is possible to grasp how much the granules P are crushed when the granules P are packed in a bag and stored in a warehouse or the like. it can.

The load test device 20 has a cylindrical container 21 capable of accommodating the granulated material P in layers and a complementary shape capable of accepting the container 21, and uniaxially accommodates the granulated material P housed in the container 21. A pressing jig 22 that presses in a direction and a pressurizing mechanism 23 to which the pressing jig 22 is fixed and pressurizes the pressing jig 22 toward the granular material P are provided.

In the load test of Example 5, the granulated material P was put into the container 21 to form a layer, and the pressing jig 22 was pushed toward the layer of the granulated material P to pressurize, and the granulated material P was crushed. The number of jigs was counted. Considering the load applied to the bagged granule P, a load of 10.0 t per 1.8 m ² was applied to the granule P. Then, the crushing rate (= number of crushed pieces / number of stored pieces) of the granulated material P was calculated.

FIG. 10 is a graph showing the relationship between the crushing rate of the granulated material P in Example 5 and the water content based on the dry amount. When the moisture content was about 5.5% or less based on the dry amount, the crushing rate was almost zero, but when it exceeded about 7.5%, the crushing rate increased sharply. From the above, in order for the granulated material P to have the strength required for bagging and storing the granulated material P, the water content is at least about 7.5% or less based on the dry amount, and preferably about. It can be understood that it must be 5.0% or less.

(Example 6)
In Example 6, the relationship between the moisture content of the granulated material based on the dry amount and the drying time after granulation was investigated. The drying time required to obtain the desired moisture content by changing the environmental temperature was measured. The environmental temperature was one of 423K, 448K, and 473K.

FIG. 11 is a graph showing the relationship between the moisture content based on the dry amount and the drying time in Example 6. In order to reduce the moisture content of the granulated material after drying to 7.5% or less based on the dry amount, it is necessary to dry at 473K for at least about 30 minutes or more, at 448K for at least about 50 minutes or more, and at 423K for at least about 90 minutes or more. There is. From the above, it can be understood that in order to shorten the drying time of the granulated material, the environmental temperature at the time of drying should be raised. From FIG. 11, it can be understood that even if the granulated material is dried for a long time, the water content of the granulated material is reduced to only about 1.0% based on the dry amount.

(Example 7)
In Example 7, a granule (granulated sample) containing scallop shell powder was actually sprayed on the soil, and the acid soil correction ability of the granulated sample was evaluated.

First, volcanic ash soil mixed with granules containing scallop shell powder was spread inside a box-shaped container at a height of 30 cm, and water equivalent to 1 mm of precipitation was sprayed from above every day. Then, 20 g each of the volcanic ash soil on the surface layer and the volcanic ash soil at a depth of 30 cm from the surface were collected every day and shaken with 50 ml of water in a shaker for 30 minutes. Then, the supernatant of each shaken solution was collected, and the pH value of each supernatant was measured. For comparison, the pH values of blank volcanic ash soil and volcanic ash soil sprayed with powdered samples were measured by the same method.

FIG. 12 is a graph showing the time course of the pH value in the surface layer of the volcanic ash soil and 30 cm inside in Example 7. When the granulated sample or the powdered sample was sprayed, the pH value of the soil was improved to 7.0 or more, unlike the case of the blank state. When the powdered sample was sprayed, the pH value gradually decreased 7 to 8 days after the spraying on both the surface layer of the soil and 30 cm inside. On the other hand, when the granulated sample was sprayed, the pH value was maintained at 7.0 or higher in both the surface layer of the soil and 30 cm inside, even 25 days after the spraying. From the above, it can be understood that the granules containing the scallop shell powder can continuously correct the acidic soil as compared with the powder containing the scallop shell powder, and as a result, the number of times of spraying can be suppressed.

(Example 8)
In Example 8, lignin was used as a binder to attempt to granulate scallop shell powder by a rolling granulation method, and the particle size distribution and strength of the granulated material were investigated. The lignin added to the scallop shell powder is a stock solution having a density of 0.82 g / ml or more or a solid component concentration of 48.6% or more diluted 6-fold or less with water. The amount of lignin added is 1 wt. %, 2 wt. %, 3 wt. %, 4 wt. %.

In the rolling granulator 10, a baffle plate for promoting aggregation of scallop shell powder was arranged in the pan 11. The baffle plate is a rectangular plate that is fixed to the outside of the pan 11 and whose tip portion contacts the bottom surface portion of the pan 11 so as to scoop up the scallop shell powder. When the bottom surface of the pan 11 is observed from above in the direction of the rotation axis, the tip of the baffle plate contacts the bottom surface of the pan 11 at a position of 90 ° in polar coordinates with the rotation axis as the origin and 0 ° to the right. The obstacle board was arranged so as to do. The rotation speed of the pan 11 was 40 rpm, and the installation angle of the pan 11 was 60 °. The granulation time was 6 minutes.

FIG. 13 is a graph showing the effect of the amount of lignin added on the particle size distribution of the granules. Even when lignin was added as a binder, granules of scallop shell powder could be obtained by the rolling granulation method as in the case of molasses. As shown in FIG. 13, even if the amount of lignin added to the scallop shell powder changes, the particle size distribution of the granules hardly changes, and the particle size distribution of the granules is in the range of about 2 mm to about 6 mm. It was. Therefore, by using lignin as a binder, it is possible to obtain granules of scallop shell powder suitable for spraying on soil regardless of the amount of lignin added.

Next, in order to grasp the strength of the granules containing lignin, a load load test was carried out on the granules to which lignin was added. The load-bearing test includes a case where a load is applied to a single granule (one particle), a case where a load is applied to a particle layer of the granule under the same conditions as in Example 5, and a case where a load is applied to the particle layer of the granule. Was carried out respectively. The amount of lignin added to the granules was 1 wt. %, 2 wt. %, 3 wt. %, 4 wt. %, 5 wt. %.

14 (a) to 14 (e) are graphs showing the results of performing a load-bearing test on individual granules. The amount of lignin added is 1 wt. In the case of%, the ratio of the granulated material crushed at the time of particle size measurement (crush rate) was about 18%, but the amount of lignin added was 2 wt. %, 3 wt. %, 4 wt. %, 5 wt. In the case of%, the crushing rates of the granules were 6.7%, 1.1%, 0.2% and 0.4%, respectively. Therefore, it can be understood that as the amount of lignin added increases, the crushing strength of the granules alone tends to increase. Further, from the graphs of FIGS. 14 (a) to 14 (e), it can be understood that the crushing strength of the granulated material increases as the particle size of the granulated material increases regardless of the amount of lignin added.

FIG. 15 is a diagram showing the crushing rate of the granulated material when a load test is performed on a single granulated material and a particle layer, respectively. From FIG. 15, when lignin is used as the binder, the amount of lignin added is adjusted so that the granules are not crushed even if the bags filled with the granules are stacked and stored in a warehouse or the like. The amount of solid component is 4 wt. It can be understood that it should be% or more.

10 Rolling granulator 11 Pan 12 Motor 13 Rotating shaft 14 Tilt adjustment mechanism 20 Load test device 21 Container 22 Pressing jig 23 Pressurizing mechanism

Claims (9)

It is a shell powder obtained by crushing a shell, and the bulk density after the tapping treatment is in the range of 0.5 g / ml to 1.3 g / ml, or the angle of repose is in the range of 55 ° to 80 °. A granular acid soil corrector containing a seashell powder classified as described above and a binder for aggregating the classified seashell powder.
The particle size of each granule of the granular acid soil corrector is in the range of 1 mm to 30 mm.
Granular acid soil corrector. Shell powder is crushed scallop shell powder.
The binder is molasses,
The granular acid soil corrective agent according to claim 1. The moisture content of each granule is in the range of 1.0% to 7.5% on a dry basis.
The granular acid soil corrective agent according to claim 1 or 2. From the shell powder obtained by crushing the shell, the bulk density after the tapping treatment is in the range of 0.5 g / ml to 1.3 g / ml, or the angle of repose is in the range of 55 ° to 80 °. And the classification process to classify
A granulation step of adding a binder to the shell powder classified in the classification step and rolling the shell powder in a rotating container to form a granule from the shell powder.
A drying step of drying the granules formed in the granulation step and
A method for producing a granular acid soil corrective agent containing. Shell powder is crushed scallop shell powder.
The binder is molasses,
The method for producing a granular acid soil corrective agent according to claim 4. The molasses liquid has a density of 1.175 g / cm ³ or more, or a solid component amount of 40 g / 100 ml or more.
The method for producing a granular acid soil corrective agent according to claim 5. In the classification step, the crushed shell powder is classified by passing it through a fine-meshed sieve of 100 mesh or more, or by sieving by wind classification.
The method for producing a granular acid soil corrective agent according to any one of claims 4 to 6. The water content of the mixture of the shell powder and the binder in the granulation step is 23.1 vol. % ~ 28.6 vol. Is in the range of%
The method for producing a granular acid soil corrective agent according to any one of claims 4 to 7. In the drying step, the granulated material is dried so as to reduce the water content of the granulated material formed in the granulated step to a range of 1.0% to 7.5% based on the dry amount.
The method for producing a granular acid soil corrective agent according to any one of claims 4 to 8.