JP2007161745A - Clay heat treatment granular material - Google Patents

Abstract

An object of the present invention is to provide a heat-treated clay granule comprising a heat-treated product of a grassy material such as rice husk and a smectite clay, having appropriate water retention and particle strength, and useful as a soil conditioner for paddy fields.
A smectite clay (A) is mixed with a plant and woody material (B) mainly composed of cellulose and hemicellulose, the mixture is granulated, and the granulated product is then heated at a temperature of 200 to 350 ° C. It is characterized by heat treatment.
[Selection figure] None

Description

  The present invention relates to a clay heat-treated granular material obtained by heat-treating grassy wood such as rice husk and smectite clay, and more particularly to a clay heat-treated granular material useful as a soil conditioner.

  In recent years, inorganic chemical fertilizers are often used in place of organic fertilizers such as compost, and the use of agricultural chemicals and herbicides for controlling pests and pests in crops has reduced the number of soil microorganisms useful for paddy and field crops. The proper balance of growth has been lost. For this reason, the circulation of elements useful for the growth of crops managed by soil microorganisms (for example, nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, etc.) is hindered, and it is said that inorganic chemical fertilizers must be replenished frequently. A vicious circle is occurring.

  Moreover, in paddy fields, low crystalline substances such as amorphous silicic acid and opal (protein), which are originally contained in soil, are produced by continuous cropping of rice (1-2 seasons / year), which is typical of silicic acid plants. Part of crystalline silicic acid, such as silicic acid and cristobalite, becomes available silicic acid (also known as effective silicic acid) in the presence of water, such as polysilicate ions and colloidal silicate particles. It is absorbed by crops and gradually decreases from the soil. In the past, rice husks and rice straw that have absorbed such silicic acid have been fermented and sown as compost, or have been directly sprayed and circulated into the soil. Circulation is less than before, and the silicic acid content that is easily absorbed by rice and the like gradually decreases from the soil, affecting the growth of crops.

  From the above viewpoint, the present inventors previously proposed a rice husk-containing composition obtained by mixing and granulating a rice husk powder and an aluminosilicate such as smectite clay (Patent Document 1). .

That is, the rice husk-containing composition is applied to the soil to replenish the silicic acid content in the rice husk into the soil, and at the same time, retain the fertilizer component by the cation exchange capacity and water retention capacity of the smectite clay. By effectively supplying fertilizer components from the roots of crops, the fertilizer effect can be sustained.
JP-A-8-224488

  However, the rice husk composition containing the smectite clay as described above causes swelling due to water, water retention is too large, and when applied in a large amount, the drainage of the soil becomes worse, and oxygen enters the soil. Therefore, there is a problem that root rot and pest damage are likely to occur. In addition, such rice husk composition has extremely weak particle strength and easily disintegrates due to water absorption. Therefore, when applied in a relatively small amount, it is washed away by rain or watering (water supply) or in the soil. There was also a problem that it penetrated deeply and the above-mentioned sustaining effect of fertilizer could not be fully exhibited.

  In order to impart water resistance to the particle strength of the smectite clay, firing is usually performed at a temperature of 500 ° C. or higher. However, when the rice husk composition as described above is fired, the rice husk component is ashed, resulting in pH. There was a problem of causing a significant increase in That is, the rice husk component is carbonized by dehydration, and further, the supply of oxygen from the atmosphere causes the oxidation of carbon, resulting in ashing. Such ashing raises the pH to, for example, about 11 (5% suspension). In addition, when heat treatment is performed at a relatively low temperature of, for example, 200 ° C. or lower, a state similar to dry distillation is obtained, and various low-molecular organic acids are generated. It will fall to the following. In either case, an extremely harmful environment is developed for crop growth.

Accordingly, an object of the present invention is to provide a heat-treated clay granule comprising a heat-treated product of grassy wood such as rice husk and smectite clay, and having an appropriate water retention and particle strength, and a method for producing the same. .
Another object of the present invention is to provide a clay heat-treated granular material useful as a soil conditioner for paddy fields and the like, and a method for producing the same.

  According to the present invention, the smectite clay (A) and the vegetation (B) mainly composed of cellulose and hemicellulose are mixed, the mixture is granulated, and then the granulated product is heated to 200 to 350 ° C. There is provided a method for producing a clay heat-treated granule characterized in that the heat treatment is preferably performed at a temperature of 230 to 300 ° C, particularly 240 to 260 ° C.

In the production method of the present invention,
(1) Use rice husk or rice straw as plant wood (B),
(2) performing granulation of the mixture by extrusion,
(3) Use of vegetation (B) in an amount of 25 to 150 parts by weight per 100 parts by weight of smectite clay;
Is preferred.

According to the present invention, the clay heat-treated granular material comprising a heat-treated product of smectite clay (A) and grass and wood (B) mainly composed of cellulose and hemicellulose,
With respect to the dried product at 200 ° C. for 2 hours, the X-ray diffraction peak of smectite on the [001] plane does not substantially exist in the region of 2θ = 5.0 to 7.5 degrees and 105 after immersion in water for 5 hours. The dried product at 2 ° C. for 2 hours has an X-ray diffraction peak of smectite [001] plane in the region of 2θ = 5.0 to 7.5 degrees,
There is provided a clay-heat treated granular material characterized by maintaining the initial particle shape even after being immersed in water for 5 hours.

In the clay heat treated granular material of the present invention,
(4) The plant wood (B) is rice husk or rice straw,
(5) The cation exchange capacity is 30 meq / 100 g or more,
Is preferred.

  In the present invention, the heat treatment is performed in a low temperature region (200 to 350 ° C.) in a state where the smectite clay (A) and the vegetation (B) are integrated by granulation. For this reason, the particle strength can be remarkably increased while appropriately securing the water retention of the smectite clay (A).

  That is, the clay heat-treated granular material obtained by the above method does not swell or disintegrate even when poured into water, and exhibits good water permeability when sprayed on soil. Specifically, in the X-ray diffraction of the dried product at 200 ° C. × 2 hours, the X-ray diffraction peak of the [001] plane of smectite is not substantially present in the region of 2θ = 5.0 to 7.5 degrees. The water (interlayer water) that exists between the layers of the smectite unit layer has been partially dehydrated, but water enters again between these layers and rehydrates (condensates), so the smectite [001] surface X-ray diffraction peak of 2θ = 5.0 to 7.5 degrees. That is, in such a clay heat-treated granular material, the inter-layer distance between smectite unit layers is not further expanded and does not swell, but exhibits an appropriate water retention.

  Moreover, when the clay heat-treated granular material obtained by the above method is put into water, the particle shape does not collapse, and the initial particle shape is maintained for a long period of time. For this reason, when this is sprayed on the soil, there is no inconvenience such as being washed away by water or penetrating deeply into the soil.

  In addition, in such a clay heat-treated granular material, since the burning of the vegetation (B) is performed in a low temperature region and in a state of being cut off from the atmosphere by integration with the smectite clay, the vegetation (B) is carbonized. It stops and does not progress to ashing through combustion. Therefore, the increase in pH due to ashing is suppressed, and the pH (5% suspension) of the clay heat treated granule is about 5 to 8.

  Furthermore, the heat-treated clay granule of the present invention has not only a fertilizing ability due to the ion exchange ability of the smectite clay, an appropriate water retention ability, and water permeability, but also both clay and grass (especially rice husk or rice straw). Because it contains silicic acid derived from, it has an excellent ability to supply silicic acid useful for crop growth, and also contains vegetative carbonization components, so it exhibits microbial activation in the soil . Therefore, the clay heat-treated granular material of the present invention is extremely useful as a soil conditioner, particularly a soil conditioner for paddy fields.

Smectite clay (A):
Smectite clays used in the present invention (A) is represented by montmorillonite and beidellite, they have a layered structure consisting of three layers of SiO ₄ tetrahedral layers -AlO ₆ octahedral layer -SiO ₄ tetrahedra layer, these A part of Al in the octahedral layer has a basic skeleton in which Mg and Fe (II) are partly substituted, and part of Si in the tetrahedral layer is replaced by Al and a low-valent dissimilar metal. Although a negative charge is generated in the substituted portion, there is a balanced amount of cation and water between the laminated layers, and the charge is neutralized. That is, the smectite clay exhibits a cation exchange capacity according to the type and amount of such a substituted metal or interlayer element. Therefore, these cation exchange and adsorption capacities capture elements from the soil, such as nitrogen (ammonia), phosphorus (phosphate), potassium, calcium, magnesium, and sulfur (sulfuric acid), which are useful for crop growth. It is possible to maintain fertilizing power. Specifically, fertilizer components such as ammonia, nitrogen, potash, calcium, and magnesium supplied to the soil by fertilization are taken in between the layers as cations such as NH ₄ ⁺ , K ⁺ , Ca ²⁺ , Mg ²⁺ , and nitrates. (Nitrogen), phosphate (phosphorus), sulfate (sulfur), and the like, as anions such as NO ₃ ⁻ , PO ₄ ³⁻ , SO ₄ ^2−, etc. Fe atom) or the like. In this way, fertilizer components trapped in smectite clay are directly absorbed and used by crops, for example, absorbed and used by microorganism cells and discharged, and further recycled and used by crops. When it is done, fertilizing power is demonstrated.

  In the smectite clay having the layer structure as described above, water enters between the layers of the unit layer, and water called interlayer water exists so as to surround the cations and hydrogen ions. That is, water retention can be shown by taking up water between layers, and water most necessary for growing crops can be secured.

  In the present invention, the smectite clay as described above can be exemplified by acid clay, fuller's earth, bentonite, sub-bentonite, etc. containing montmorillonite, beidellite, nontronite and the like as main clay mineral components. Natural products or synthetic products may be used. Moreover, as long as the above-mentioned characteristics are maintained, an acid-treated product such as activated clay can be used. As natural smectite clay, amorphous silicic acid, low crystalline silicic acid such as opal (crystallite) or crystalline silicic acid such as cristobalite (because of alkali solubility, these are soluble below. Those that are produced together with silicic acid) are preferred. That is, the smectite clay produced in a certain kind of production area contains the above-mentioned silicic acid content in a state of being united with the fine crystals of smectite (usually 10% by weight or more, particularly 40% by weight or less). ). Such soluble silicic acid content easily forms the above-mentioned available silicic acid in the presence of water, and is easily absorbed by vigorous absorption of crop roots. Therefore, in the present invention, a smectite clay containing such a silicic acid component is preferably used.

  By the way, the above-described smectite clay exhibits water retention as described above, and at the same time, in the presence of excessive moisture, swelling occurs depending on the type of smectite clay, but the basic unit layer of smectite clay is It disperses into discrete colloidal forms and becomes fluidized. If this is left as it is, a card house structure is formed by suction repulsion between the unit layers, resulting in a highly thickened or gelled state (solidified state). If it will be in such a state when supplying to soil, water permeability will be impaired.

  In addition, smectite clay has a low particle strength, and easily disintegrates in water. When such particle collapse occurs, for example, when sprayed on the soil, it is easily washed away by water or deeply settled in the soil together with water.

  Therefore, in the present invention, the heat treatment described below is performed in order to reduce the swelling / solidifying performance and increase the particle strength to such an extent that the fertilizing power and water retention derived from the cation exchange capacity of the smectite clay are not impaired. Is necessary.

Plant wood (B):
In the present invention, the vegetation used in combination with the above smectite clay is mainly composed of cellulose and hemicellulose and usually further containing lignin, but the siliceous content is particularly high (usually 10 % Or more) Rice husks and rice straw derived from rice are preferred. That is, these contain silicic acid and minerals absorbed from the soil, and in particular, silicic acid is originally easily absorbed by crops.

  By the way, the silicic acid content contained in the vegetation is in silicified cells surrounded by a cell membrane made of cellulose, so that it is not released to the outside as it is, for example, it does not leach to the outside even if it is sown in the soil. . That is, the heat treatment described later is performed in order to break down such a cell membrane and easily release the internal silicic acid content to the outside simultaneously with the above-described modification of the smectite clay.

(Manufacture of clay heat-treated granules)
In the present invention, the above-mentioned smectite clay (A) and vegetation (B) are mixed, granulated, and then heat-treated to produce a heat-treated clay granule.

  The smectite clay (A) and the vegetation (B) are used in an amount ratio such that the vegetation (B) is 25 to 150 parts by weight, particularly 50 to 100 parts by weight per 100 parts by weight of the smectite clay. Is preferable. If the amount of vegetation used is greater than the above range, fertilizing power and water retention derived from smectite clay will be unsatisfactory, and heat treatment described below will not suppress ashing of vegetation, resulting in a significant pH. May cause an increase. Furthermore, if the amount of vegetation used is less than the above range, the ability to supply silicic acid derived from the vegetation and the ability to activate microorganisms will be unsatisfactory, and smectite may be denatured by heat treatment in the low-temperature region described below. May be difficult.

  In addition, when mixing the smectite clay (A) and the vegetation (B), it is preferable to pulverize the vegetation beforehand. In other words, husks such as rice husks are quite bulky, so when used as they are, mixing and granulation makes it difficult to integrate with the smectite clay and suppresses ashing of the vegetation during heat treatment. Or modification of the smectite clay by heat treatment may be difficult. Such pulverization of vegetation is preferably carried out in a dry state using an impact pulverizer such as a fine pulverization hammer mill so that the particle size passing through 16 mesh is 70% by weight or more of the whole. It is.

  The granulation after the smectite clay (A) and the vegetation (B) are mixed can be performed by various means such as rolling granulation and extrusion granulation using an extruder. Extrusion granulation is preferred because it can be granulated in an integrated form, and considering the handleability, functionality when sprayed on soil, etc., the minor axis is about 1 to 3 mm and the major axis is 20 mm or less. A columnar shape is preferable.

  The heat treatment of the granular material thus obtained is performed at 200 to 350 ° C., preferably 230 to 300 ° C., particularly 240 to 260 ° C. That is, such a temperature range is a slightly higher range than the drying temperature range, thereby eliminating the swelling / solidifying property of smectite clay while maintaining appropriate water retention and fertilizer retention. At the same time, it is possible to increase the particle strength and carbonize the vegetation.

  In general, for smectite clays such as acid clay and bentonite, means such as heat treatment are used to eliminate swelling and solidification performance while maintaining basic properties such as water retention and ion exchange capacity, and to increase particle strength. Although conventionally performed, such a heat treatment temperature is usually 500 ° C. or higher, and at 500 ° C. or lower, particularly at a temperature lower than 400 ° C., the loss of swelling / solidification property and the increase in particle strength can be achieved. Can not. However, according to the present invention, such an object can be achieved in the low temperature region as described above, which is extremely unexpected. That is, in the present invention, the reason why the loss of swelling / solidification performance and the increase in particle strength can be achieved by the heat treatment in the low temperature region as described above is not clearly elucidated. Since heat treatment is performed in an integrated state with the smectite clay, it seems that some organic components in the vegetation function as a binder that bonds the basic layers of the smectite clay.

By the way, it is presumed that carbonization by intramolecular dehydration of organic components (cellulose, hemicellulose, lignin, etc.) contained in the vegetation progresses as follows.
Cellulose, hemicellulose:
(C ₆ H ₁₀ O ₅ ) _n = (C ₆ · H ₁₀ O ₅ ) _{n
= (C 6 · 5H 2 O} ) n = [ dehydrated] ⇒ _{(C) 6n}
Lignin: (Chemical composition of the next line is quoted from Iwanami-Rikagaku Dictionary)
C ₁₈ H ₂₄ O _{11 to} C ₄₀ H ₄₅ O _{18
= C 18 · H 2 · H} 22 O 11 ~C 40 · H 9 · H 36 O 18
= [Dehydration] => (C) _18-40 · H _2-9

  In the present invention, since the heat treatment is performed in the low temperature region in the form of a granular material in which the grass and the smectite clay are integrated, the organic components in the grass are burned even when the heat treatment is performed in the atmosphere. Without being carried out, there is an advantage that carbonization can be carried out by almost intramolecular dehydration, ashing thereof can be suppressed, and an increase in pH due to ashing can be avoided. That is, the integration with the smectite clay suppresses the contact with the vegetative oxygen, and the heat treatment is performed at a low temperature, so that such an advantage is achieved. In such a temperature range, a dehydration reaction can easily proceed without incomplete combustion at a low temperature of 300 ° C. or lower, particularly around 250 ° C., and toxic substances such as dioxins are also produced at all. Without being able to carbonize vegetation.

  For example, when the heat treatment temperature is higher than the above range, ashing of vegetation progresses, leading to an increase in pH and a tendency to decrease water retention. Furthermore, when the heat treatment temperature is lower than the above range, the swelling and solidification performance of the smectite clay can not be lost, and therefore, the permeability of the obtained clay heat treated granule cannot be secured, In addition, the carbonization of the vegetation is not performed effectively, and the advantages of the calcification of the vegetation (leaching ability of silicic acid and the ability to activate soil microorganisms) cannot be enjoyed. Furthermore, when the heat treatment is performed separately without integrating the smectite clay and the vegetation, for example, the heat treatment within the above range may eliminate the swelling / solidification property of the smectite clay. It cannot be increased. In addition, a mixture of a smectite clay that has been heat-treated in a high-temperature region where the swelling / solidification performance is lost and the particle strength is increased, and a vegetation-based carbide by heat treatment in the so-called oxygen barrier, and granulated, The integration of the two is insufficient, and the vegetative carbide is easily washed away by water.

  In the present invention, the heat treatment in the low-temperature region described above is performed so that the characteristics of the heat-treated product such as ion exchange capacity, pH (5% suspension), particle strength, and the like are within the ranges described later. Although it is different, it is about 20 to 60 minutes. If this heat treatment time is longer than necessary, the ashing of vegetation progresses and the pH may increase.

(Clay heat treatment granular material)
The clay heat-treated granular material of the present invention thus obtained contains a smectite clay heat-treating component, a grassy carbon component, and a silicic acid derived from the grassy material.

  Moreover, since this clay heat-treated granular material is obtained by heat-treating the above-mentioned integrated granular material of smectite clay (A) and grassy wood (B) in a low temperature region, it is dried at 200 ° C. for 2 hours. According to the X-ray analysis of the product, the X-ray diffraction peak of smectite on the [001] plane does not substantially exist in the region of 2θ = 5.0 to 7.5 degrees (see FIG. 1), and 5 hours in water. In the X-ray analysis of the dried product at 105 ° C. for 2 hours after immersion, the X-ray diffraction peak of smectite [001] plane is in the region of 2θ = 5.0 to 7.5 degrees (see FIG. 2). ). That is, in this heat-treated product, in the dry state, the interlayer of the basic unit layer of smectite clay is shrunk, but in the presence of moisture, water is taken in as interlayer water and the layer expands (re-watering). Sum or condensate), meaning that the layers do not expand even further. Due to such a smectite clay heat treatment component having definite interlaminar expansibility, the clay heat treated granular material of the present invention exhibits an appropriate water retention and exhibits good water permeability due to loss of swelling and solidification performance.

  When a smectite clay containing more soluble silicic acid such as opal is used, as shown in FIGS. 1 and 2, [111] of such soluble silicic acid is used. X-ray diffraction peak derived from the surface appears as a broad peak having an apex in the region of 2θ = 21.5 to 22.5 degrees and a half-value width in the range of 0.4 to 0.8 degrees. . Such soluble silicic acid is gradually ionized or colloidated in the presence of water by the action of soil microorganisms, physicochemical action from the roots of crops or alkali ions dissolved in water, and the like. It is thought to elute as an acid. This means that such soluble silicic acid is supplied to the crop when sprayed onto the soil.

  Furthermore, the heat-treated granule of the present invention has increased particle strength by the heat treatment described above, and retains the initial particle shape even after being immersed in water for 5 hours. That is, when the heat treatment described above is not performed or the heat treatment is insufficient, the particles rapidly disintegrate when dropped in water, for example, when washed on the soil, it is washed away with water or soil with water. It penetrates deep inside and does not contribute effectively to crop growth. However, in the present invention, the particle strength is increased, and particle collapse does not occur even when dropped in water. Therefore, when sprayed on the soil, it is washed away with water or penetrates deeply into the soil. It can be effectively avoided.

  As described above, the heat-treated clay granule of the present invention has a cation exchange capacity because it contains components that retain the basic characteristics of smectite clay. Such a cation exchange ability exhibits excellent fertilizer retention as already described. This cation exchange capacity is usually 30 meq / 100 g or more, particularly 40 to 70 meq / 100 g, although it varies depending on the physical properties and the amount of smectite clay used.

  Moreover, since the ashing of the organic component in the vegetation is suppressed, an increase in pH due to the ashing is also effectively suppressed. For example, the pH of a 5% suspension of smectite clay varies depending on the type, and is generally in the range of 4.5 to 8.5 for acid clay and 9.5 to 10.5 for bentonite. Accordingly, the pH of the 5% suspension of the heat-treated clay granule of the present invention varies depending on the type of smectite clay used, but is usually in the range of 5 to 8, particularly 5.5 to 7.5. Therefore, the influence on the growth of crops due to the increase in pH can be ignored.

  In the clay heat-treated granular material of the present invention, as described above, the organic components of the vegetation are carbonized, but the carbonization of such organic components is originally in the vegetation such as rice husks absorbed from the soil. It means that a silicic acid content (that is, a silicic acid content that easily forms available silicic acid) is released from the cell membrane and exists in a state of being easily eluted. Therefore, the clay heat-treated granular material of the present invention has an excellent ability to supply silicic acid due to such silicic acid content. Of course, such ability to supply silicic acid is further improved when a smectite clay containing soluble silicic acid is used. Conversely, if the crop does not require a high amount of silicic acid, it can be mixed with smectite clay using large sawdust of vegetation that does not contain a large amount of silicic acid, for example, broad-leaved trees such as oak and conifers. The clay heat-treated granule of the present invention can also be obtained by granulating and heat-treating.

  Moreover, since the clay heat-treated granular material of the present invention contains the carbonized component of the organic component in the vegetation, it is excellent in the ability to activate microorganisms. Microorganisms symbiotic with crops, microorganisms beneficial to the growth of crops such as nitrogen-fixing bacteria, nitrifying bacteria, etc. are vulnerable to competition with general microorganisms, but the above carbonization component (ie charcoal) is vulnerable to such competition. It is an optimal breeding place for microorganisms. That is, charcoal has many pores, good water retention, and contains a lot of air. For this reason, by spreading charcoal to the soil, the roots of crops grow well, and useful microorganisms (also called EM) can be easily propagated. However, since charcoal does not contain organic components, the microorganisms that decompose it as nutrients do not propagate, and as a result, nitrogen-fixing bacteria and photosynthetic bacteria grow and symbiosis with the roots of the crops. Microorganisms (rhizobium and mycorrhizal fungi) will also increase. Therefore, the application of charcoal provides a soil in which microorganisms useful for crops can easily propagate. The clay heat-treated granular material of the present invention containing such charcoal (carbonized component) has a high ability to activate microorganisms, and is extremely useful for providing soil suitable for crop growth.

  Thus, the clay heat-treated granular material of the present invention has a fertilizer retention due to cation exchange capacity (sustainability of fertilizer effect by capturing fertilizer components), has an appropriate water retention, and has good water permeability, Furthermore, it has a high silicic acid supply ability and an excellent ability to activate microorganisms. Therefore, it is extremely useful as a soil conditioner, and can be used, for example, as a soil conditioner for paddy fields, field action, and horticulture. In particular, for silicate plants such as rice, stems and roots can be strengthened. For example, as shown in Application Example 1 to be described later, when used for paddy fields, it has a significant effect on the enhancement of rice stems and roots, and is extremely useful in terms of prevention of lodging. In addition, as shown in Application Example 2, for example, when used in a green vegetable planter or field cultivation such as a beet vegetable, the leaf portion may be due to an increase in the amount of chlorophyll produced due to high fertilizer. It becomes darker green and the yield (weight of edible part) is improved.

  The effect of the clay heat treated granule according to the present invention as a soil conditioner is not limited to the above two application examples, and its application is generally classified into leafy vegetables, fruit vegetables, root vegetables and flower vegetables. It is useful for cultivation of edible crops such as edible fungi, potatoes, beans, cereals and fruit trees, cultivation of flowering plants, planting of plants, and the like. Of course, it can also be applied to rice seedlings and mushroom fungus beds, and can also be applied to planters and pots in home gardening along with soil.

  In addition, the clay heat-treated granular material of the present invention has high heat retention and is not washed away with water or penetrates deeply into the soil, so it is also useful as a snow-melting soil improving material for cold fields. .

The invention is illustrated in the following examples.
Each test method followed the following method.

(1) X-ray diffraction Preparation of measurement sample:
A granular or coarse sample is ground in a mortar by a conventional method to obtain a powdery measurement sample.
X-ray diffractometer:
Rigaku Co., Ltd., MultiFlex
Measurement condition:
X-ray = Cu-Kα ray, tube voltage = 40 kV, tube current = 30 mA,
Divergence slit = 0.15mm, scattering slit = 1 °, light receiving slit = 0.15mm
Scanning range:
Diffraction angle (2θ) = 3 ° -40 °

(2) Determining interlaminar expansibility X-ray diffraction before immersion in water (A):
A granular material sample (1 g) is dried at 200 ° C. for 2 hours, and X-ray diffraction is performed by the above method.
X-ray diffraction after immersion in water (B):
A sample of 1 g of a granular material is put into 100 mL of water, and the sample which has been solid-liquid separated after being immersed in water for 5 hours is dried at 105 ° C. for 2 hours, and X-ray diffraction is similarly performed.
Fixed layer extensibility:
In the X-ray diffraction (A) of the dried product at 200 ° C. for 2 hours, the X-ray diffraction peak of the [001] plane of smectite is substantially not present in the region of 2θ = 5.0 to 7.5 degrees, and In X-ray diffraction (B) of a dried product at 105 ° C. for 2 hours after being immersed in water for 5 hours, the X-ray diffraction peak on the [001] plane of smectite is in the range of 2θ = 5.0 to 7.5 degrees. In this case, it is determined that there is a definite interlaminar expandability due to rehydration, and is represented by the following determination symbol.
○ X-ray diffraction image satisfies the above requirements, and clay components are rehydrated by immersion in water
Water retention is expressed by holding water between layers.
X: X-ray diffraction image does not satisfy the above requirements.
― ・ ・ ・ Solids are difficult to separate by immersion and submergence due to immersion in water.
However, “having an X-ray diffraction peak of the [001] plane in the region of 2θ = 5.0 to 7.5 degrees” means that the peak apex can be clearly identified by one visually. The value obtained by dividing the height (intensity: CPS) in the y-axis direction from the baseline of the apex position by the half-value width (2θ: °) of the peak with reference to the height is, for example, 100 or more A mountain-shaped peak is recognized, and conversely, the peak is “substantially non-existent” means that a clear mountain-shaped peak as described above exists in the region of 2θ = 5.0 to 7.5 degrees. Is not to. Further, the above-mentioned requirement regarding the constant interlayer expandability of the present invention does not relate to a peak existing in a region exceeding 2θ = 7.5 degrees.

(3) Determination of particle shape retention From 1 g of granular material sample in 100 mL of water, the presence or absence of disintegration when immersed in water and the hardness of the particles after immersion for 2 hours, the particle shape retention was evaluated, It is represented by the following evaluation symbol.
○… The original grain shape is maintained even after being immersed in water for 5 hours or longer, and the grain collapse is observed.
I can't.
× ・ ・ ・ The particles were disintegrated into mud within 5 hours after being put into the water, becoming the original particle shape
The shape is not kept.

(4) Cation exchange capacity (= cation exchange capacity, CEC: meq / 100 g)
Compliant with the method of “12 cation exchange capacity (CEC)” in “Guide for soil and plant analysis” issued by the Department of Agriculture, Forestry and Fisheries of Niigata

(5) Available silicic acid (= effective silicic acid, mg / 100 g)
Compliant with the method of “16 Effective Silicic Acid (SiO ₂ )” issued by Niigata Prefectural Agriculture, Forestry and Fisheries Department (H11.3) “Guide for Analyzing Soil and Plants”

(6) pH
5 g of a granular material sample is put in 95 g of pure water, and the whole is stirred about 10 times with a glass rod and allowed to stand for 15 minutes, and then the pH of the upper liquid is measured using a glass electrode type pH meter.

(7) Soluble silicic acid (%)
A sample 150 g dried at 110 ° C. is dispersed in 450 g of pure water, 53.3 g of sodium hydroxide (NaOH) is added, and the mixture is heated and stirred at 100 ° C. for 5 hours. Allow to cool and measure the total weight of the dissolved reaction solution. The dissolved mother liquor is allowed to stand for 1 day or longer to allow the solid content to settle, and a transparent supernatant is collected to quantify the SiO ₂ concentration in the solution portion. The amount of SiO ₂ eluted from 100 g of the sample is obtained by calculation and used as the soluble silicic acid (%) in the sample.

Example 1
Smectite clay (A):
About 350 kg of lump of acid clay from Shibata City, Niigata Prefecture is granulated with a pre-extrusion kneading granulator (Eck pelleter, granulated plate: 6 mmΦ) to obtain coarse clay particles (moisture: 42.0%, pH: 5.2) It was.
Plant wood (B):
About 260 kg of dried rice husk from paddy rice produced in Shibata City, Niigata Prefecture was pulverized with an impact pulverizer (fine pulverized hammer mill) to obtain rice husk powder (water content: 5.0%, pH: 5.7).
Granulation and drying:
300 kg of clay coarse particles obtained as smectite clay (A) and 183 g of rice husk powder obtained as plant wood (B) are mixed together with an appropriate amount of water, and a pre-extrusion kneading granulator (granulating plate: 5 mmΦ) Then, the mixture was further passed through the same granulator (granulating plate: 3 mmΦ) to obtain an AB mixed granulated product (water content 37.8%). Next, it was dried with a shelf dryer (110 ° C.) to obtain about 350 kg of a granulated product.
Heat treatment:
The obtained granulated material is laid on a stainless steel bat to a thickness of about 5 cm, placed in a box-type electric dryer, heated to 250 ° C., and heat-treated at that temperature for 40 minutes. The reaction progressed and a black granular material was obtained.
Table 1 shows the test results and the like of the obtained granular material.

Example 2
When the dried granulated product obtained in Example 1 was continuously charged in a rotary dryer and heat-treated (residence time: about 30 minutes, outlet temperature: 300 to 350 ° C.), dehydration and carbonization proceeded together with fuming, so Granular material was obtained.
Table 1 shows the test results and the like of the obtained granular material.

  From this, the clay heat-treated granule of Example 1 and Example 2 has a moderate water retention property because it has definite interlaminar expansibility, and has water permeability because it retains the particle shape even when immersed in water. From the fact that it has a high cation exchange capacity and a high fertilizing ability, it can be seen that it is an excellent soil conditioner having a large amount of available silicic acid and a pH within an appropriate range.

Example 3
Smectite clay (A):
About 2 kg of mass of subbentonite from Shibata City, Niigata Prefecture is granulated with a pre-extrusion kneading granulator (small size for experiment, granulation plate: 5 mmφ), and coarse clay particles (water: 33.0%, pH: 9.0) Got.
Plant wood (B):
Sawdust derived from Kashiwagi, Iwafune-gun, Niigata Prefecture, was sieved with a sieve (18.5 mesh: 0.85 mmΦ) to obtain sawdust powder (moisture: 22.6%, pH: 5.8).
Granulation and drying:
1 kg of coarse clay particles obtained as smectite clay (A) and 433 g of sawdust powder obtained as plant wood (B) are mixed with an appropriate amount of water, and a pre-extrusion kneading granulator (small size for experiment, granulation) A plate: 5 mmΦ) was applied twice, and then the granulator (granulation plate: 3 mmΦ) was applied once to obtain an AB mixed granulated product (water content 38.5%). Subsequently, it dried with the box-type electric dryer (110 degreeC), and obtained the granulated material about 1kg.
Heat treatment:
The obtained granulated material is laid on a stainless steel bat to a thickness of about 5 cm, placed in a box-type electric dryer, heated to 250 ° C., and heat-treated at that temperature for 40 minutes. The reaction progressed and a black granular material was obtained.
Table 1 shows the test results and the like of the obtained granular material.

  From this, the clay heat-treated granular material of Example 3 has a moderate water retention from having definite interlaminar expansibility, and has a higher water permeability than a particle shape even when immersed in water. From the fact that the exchange capacity is large, the fertilizer is also high and it can be seen that it is an excellent soil conditioner.

Comparative Example 1
It was manufactured in the same manner as in Example 1 except that the heat treatment was performed at a temperature of 150 ° C.
That is, the mixed dried granulated product obtained in Example 1 was laid on a stainless steel vat to a thickness of about 5 cm, placed in a box-type electric dryer, heated to 150 ° C., and kept at that temperature for 40 minutes. Heat treatment was performed to obtain an ocherous granular material.
Table 1 shows the test results and the like of the obtained granular material.

  From this, the granular material of Comparative Example 1 has excessive water retention rather than being disintegrated and swollen in water to make it muddy, so that the water permeability (drainage) and air permeability of soil are poor by application, and the pH is also crop. It is lower than the soil suitability range and is not suitable for soil conditioner.

Comparative Example 2
1 kg of coarse granulate derived from subbentonite obtained in Example 3 and 200 g of rice husk charcoal (commercial product, moisture: 16.6%, pH: 11.1) were mixed with an appropriate amount of water, and a pre-extrusion kneading granulator ( A small size for experiment, granulated plate: 5 mmΦ) was applied twice, and then the granulator (granulating plate: 3 mmΦ) was applied once to obtain an AB mixed granulated product (water content 38.5%). Subsequently, it dried with the box-type electric dryer (110 degreeC), and obtained the granulated material about 1kg.
The obtained granulated material is laid on a stainless steel bat to a thickness of about 5 cm, placed in a box-type electric dryer, heated to 150 ° C., heat-treated at that temperature for 40 minutes, and dark gray granular material. Got.
Table 1 shows the test results and the like of the obtained granular material.

  As a result, the granular material of Comparative Example 2 has excessive water retention rather than disintegrating / swelling in water and becoming muddy, so that the water permeability (drainage) and air permeability of the soil is poor by application, and the pH is also crop. It is higher than the soil suitability range and is not suitable as a soil conditioner.

  Next, an application example in which the clay heat-treated granular material according to the present invention is applied to the cultivation soil of rice and green vegetables will be described.

Application example 1 (direct sowing cultivation of rice)
Nine concrete pots (1.6m x 1.0m), covered with normal paddy soil, were layered approximately 20cm from the top surface of the soil, and 300g of clay heat-treated granular material according to Example 1 per m ² (application) Example 1-1, 3 pots) and 150 g (application example 1-2, 3 pots) were seeded together with the basic fertilizer 6 days before sowing. As a control plot, a mixture prepared by mixing the same amount of basic fertilizer (Application Comparative Example 1-1, 3 pots) was also prepared.
Sowing (seeds immediately after germination, cultivar: Koshihikari) was carried out on May 10, 2004 by direct sowing at a planting density of 100 strains / m ² , and topdressing was carried out on June 20 and July 30. . Harvesting took place on September 22, 135 days after sowing. In addition, on August 31, a strong wind (5 to 10 m / s) due to the influence of a typhoon was received, and a flutter-type lodging with a stem curved in some pots was observed.
The test results and the like obtained are shown in Table 2.

  As can be seen from the results in Table 2, in the direct sowing cultivation of rice in the pot in which the clay heat-treated granular material of the present invention is sown, the silicic acid content in the stem is slightly large, and the lodging prevention effect is high ( The pushing resistance value was measured on August 30 before partial lodging due to strong wind, and the lodging rate was determined on September 4. Due to the lower level of lodging of ripening rice and the improvement of soil fertility, various fertilizer components such as ammonia nitrogen were appropriately supplemented, and in-vivo synthesis of chlorophyll and the resulting photosynthesis were actively performed. However, various indicators related to yield have also increased. Moreover, for the purpose of improving the water retention capacity of the soil, the water content in the polished rice was high, and the occurrence of heart white rice was small. Furthermore, the protein content in the polished rice was low, and it was evaluated that it had an effect of improving the taste of rice.

Application example 2 (planter cultivation of beeri vegetables)
A normal upland field soil is passed through a sieve (8 mesh, 2.4 mmΦ) to make a fine-grained soil, and 1 L of the same soil and 1 L of the heat-treated clay heat-treated material 1 L are mixed well and mixed soil (Application Example 2-1) And 1.5 L of the plant was laid in a planter (unglazed ceramic pot, internal volume: 2 L).
For comparison, instead of the above clay heat-treated granular material, the granular material according to Comparative Example 1 (chaff-clay mixed granular material), pearlite (granular material, on 16 mesh) as a soil improvement material for commercially available agricultural and horticultural / artificial soil: about 50%) and 1L of the above-mentioned field soil and mixed soil (Application Comparative Examples 2-1 and 2-2) well mixed with 1L of ground soil that has been made fine through a sieve. Laying on similar planters.

<Test on water retention and fertilization>
Three bowls each containing mixed soil were placed on a drying shelf set at 110 ° C. for 36 hours, and all were made dry soil, and the weight was calculated. Pure water is poured evenly over the entire surface of the pot to supply water, and when excess water that cannot be fully hydrated from the soil flows out from the bottom drainage hole, stop the water supply and leave it for 1 minute, then filter the bottom surface (drainage hole) The water adhering to the surroundings was wiped off and weighed, and the amount of water held by the whole pot (primary water holding amount) was calculated from the difference from the previously calculated dry soil weight. Next, the amount of water retained (secondary amount of water retained) after performing processing that imitates the high temperature drying climatic conditions under drought after putting 3 bowls each holding water in a 60 ° C dryer for 24 hours. The same calculation was performed. Further, 200 mL of a 250-fold diluted solution of a commercially available liquid fertilizer stock solution (Hyponex, internal ammonia nitrogen: 2.9%) is poured evenly from above onto each pot placed on a clean plastic tray, and left for 1 hour. Pure water was poured evenly over the entire surface of the pot to supply water, and the water supply was stopped when excess water that could not hold the cultivated soil flowed out of the bottom drain hole. After leaving for 1 minute, the water adhering to the outer surface of the bottom (around the drain hole) was wiped off with a filter paper and weighed, and the amount of water held by the whole pot (third water holding amount) was calculated as before. At the same time, collect about 2 mL of water flowing out of the tray by decantation, add 5 drops of Nessler's reagent, observe the presence or absence of ammonia nitrogen from the appearance of brown precipitates, and mix culture soil The degree of adsorption / trapping ability of the phase with respect to ammonium ions was considered as one index of fertilizing ability and expressed qualitatively according to the following evaluation criteria. The results obtained in this test are shown in Table 3.
○ ・ ・ ・ There is no or very small amount of ammonia in the water spilled by the water supply after fertilization (brown
Precipitation:-~ ±), and it is almost adsorbed or retained in the mixed culture phase
The fertilizer is high.
△ ... Amount of ammonia in the water spilled by water supply after fertilization to some extent (brown precipitation: + ~ +
+) And seems to be retained to some extent in the mixed soil phase.
× ・ ・ ・ Amount of ammonia in the water flowing out of the fertilizer after fertilization is 500 times less than the liquid fertilizer stock solution
Ammonia adsorbed on the mixed soil, which is close to the level of solution (brown precipitate: +++)
There are not many near and fertilizer is low.

<Cultivation experiment>
As described above, 1.5L of 3 types of mixed soil is filled, and a dent (3 places) is made with fingers in the center of each of the three pots filled with liquid fertilizer (original fertilizer) and supplied with water. Of seeds (variety: beet vegetables, standard germination rate: 85% or more) one by one, apply soil to a thickness of 2 to 3 mm from the top, place filter paper and feed water by sprinkling water from above. The pots after sowing were placed indoors and germination was observed after 2 days. After 3 days, all seeds (3 grains) in each pot were germinated and became twin leaves. There was a slight difference in the size of three of the Futaba in each pot, and the smallest one was thinned to leave two. Then, the pot was taken out outdoors, exposed to the open-air, and watered appropriately. After 14 days, there was a slight difference in the growth of the two bodies in each pot, but the other one was thinned out except for the slightly larger one, and the growth data was taken. The same amount of liquid fertilizer as that used for the original fertilizer (200 mL) was additionally fertilized. After that, only water was supplied as appropriate and harvested after 35 days to complete the cultivation test. Table 3 also shows the growth data and the like of the green vegetables obtained in this experiment.

  As can be seen from the results in Table 3, the mixed soil containing the heat treated granulated clay of the present invention had a pH in an appropriate range, moderate water retention, and good rooting. Because fertilizers are sufficient, fertilizer components such as ammonia nitrogen are appropriately supplemented, and the in-vivo synthesis of chlorophyll and the resulting photosynthesis are actively performed. Various indicators related to were also high. The leaf color was dark green and the commercial value was high, and the taste of “Ohitashi” was good with a deep taste.

The X-ray-diffraction image about the 200 degreeC * 2 hour dried material of the clay heat processing granule of this invention manufactured in Example 1 is shown. The X-ray-diffraction image about 105 degreeC x 2-hour dried material after immersion for 5 hours throwing into the water of the clay heat processing granule of this invention manufactured in Example 1 is shown.

Claims (10)

  Mixing smectite clay (A) with plant wood (B) mainly composed of cellulose and hemicellulose, granulating the mixture, and then heat treating the granulated product at a temperature of 200 to 350 ° C. A method for producing a granulated clay heat treated product.   The method of producing a clay heat-treated granule according to claim 1, wherein the heat treatment is performed at a temperature of 230 to 300 ° C.   The method for producing a heat-treated clay granule according to claim 1 or 2, wherein rice husk or rice straw is used as the vegetation (B).   The method for producing a clay heat-treated granule according to any one of claims 1 to 3, wherein granulation of the mixture is performed by extrusion molding.   5. The method for producing a clay heat-treated granule according to any one of claims 1 to 4, wherein the vegetation (B) is used in an amount of 25 to 150 parts by weight per 100 parts by weight of the smectite clay. In the clay heat-treated granular material composed of a heat-treated product of smectite clay (A) and plant wood (B) mainly composed of cellulose and hemicellulose,
With respect to the dried product at 200 ° C. for 2 hours, the X-ray diffraction peak of smectite on the [001] plane does not substantially exist in the region of 2θ = 5.0 to 7.5 degrees and 105 after immersion in water for 5 hours. The dried product at 0 ° C. for 2 hours has an X-ray diffraction peak of smectite [001] plane in the region of 2θ = 5.0 to 7.5 degrees,
A heat-treated clay granule having an initial particle shape after being immersed in water for 5 hours.   The heat-treated clay granule according to claim 6, wherein the plant wood (B) is rice husk or rice straw.   The clay heat-treated granule according to claim 6 or 7, having a cation exchange capacity of 30 meq / 100 g or more.   A soil conditioner comprising the clay heat-treated granular material according to any one of claims 6 to 8.   The soil conditioner according to claim 9, which is used for paddy fields.

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