Granular fertilizer and method for producing granular fertilizer

Abstract

To develop techniques for processing an organic material derived from animals into an organic fertilizer which is odorless and is rich in fertilizer active components such as nitrogen, phosphate and potassium salt.SOLUTION: Disclosed are: an organic fertilizer which is a granular fertilizer using an organic material derived from animals and having a particle diameter of 2-8 mm, where a nitrogen content is at least 1.5 times that of the organic material, the phosphate content is at least 1.5 times that of the organic material, and the potassium content is at least 1.3 times that of the organic material; and a manufacturing method thereof.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an invention in the field of fertilizer and its manufacturing technology. [Background technology]

[0002] Livestock manure compost, an organic material derived from animals, is used as organic fertilizer because it contains the three major elements that significantly affect crop growth: nitrogen, phosphorus, and potassium. The amounts of nitrogen, phosphorus, and potassium contained in compost are highest for chickens, followed by pigs and cows, respectively. However, the amount of organic matter required for soil improvement is highest for cows, pigs, and chickens, in that order. Furthermore, while the amount of nitrogen available to crops in the year of application is low, the high content of sparingly soluble nitrogen accumulates in the soil, and this nitrogen accumulates in the soil and is continuously supplied to subsequent crops. In other words, with repeated application, nitrogen is supplied not only from the compost applied in the current year but also from compost applied in previous years. Therefore, repeated application of cow manure compost is said to increase soil fertility and produce a continuous application effect, increasing nitrogen supply (Non-Patent Document 1).

[0003] A method for producing organic fertilizer is known in which fertilizer raw materials such as livestock waste are adjusted to a moisture content of 40-60% by weight, and then this is sheared and kneaded under pressure to produce a mixture heated to 40-90°C by the frictional heat of the pressurization and kneading. This processed material is then crushed into granules in a screw-type granulator while ozone (O3) is supplied to oxidize the surface of the processed granules with the ozone, creating conditions that suppress the activity of thermophilic anaerobic bacteria and promote the activation of thermophilic aerobic bacteria, and the processed material is then fermented (Patent Document 1). However, while one effect of this method is that odors caused by the ozone can be suppressed, the fertilizer produced by this method is in the form of pellets, and no description is given of its effectiveness as a fertilizer.

[0004] A method for granulating organic fertilizer from fermented chicken manure or other materials is known, in which powder of organic raw material, such as fermented chicken manure, is fed from above into a cylindrical housing with rotors rotating at high speed inside, suspended within the housing, which rotates vertically and circumferentially while also rotating on its axis, numerous water droplets are sprayed inside the housing to agglomerate the powder, and after a required time has elapsed, a powder coating agent is fed into the housing to coat the surfaces of the agglomerated powder granules with the coating agent. This method (Patent Document 2) is characterized in that the powder is suspended, swirled, and agitated solely by the rotational force of the rotors, without the supply of high-pressure air or a perforated disk for fluidizing the powder along with the supply of high-pressure air. However, this method is limited to certain powder raw materials, such as chicken manure, and cannot be used as a compost raw material with a moisture content exceeding 50%, and the coating is required, which is time-consuming and costly. Furthermore, changes in active ingredients such as phosphate, nitrogen, and potassium, as well as granule shape, have not been investigated.

[0005] A granular organic fertilizer composition (Patent Document 3) is known in which dried fermented chicken manure is sieved and granulated using a screw-shaped extrusion granulator, in which a small amount of water is added to the fermented chicken manure to form granules, and the surface of each granule is coated with a powder that enhances fertilizer efficacy, resulting in the individual granules being separated from each other. However, this composition has limitations such as being limited to powdered chicken manure and requiring a coating process, and does not describe any changes in active ingredients such as phosphoric acid, nitrogen, or potassium.

[0006] Unlike the above-mentioned methods for producing organic fertilizers using a screw-type extrusion granulator or a high-speed rotary granulator, there is a known method for producing low-density porous carbon granules, in which plant-based powder is granulated in a pin-type granulator with an aqueous solution of a binder component consisting of lignin, starch, or a mixture of these, and the granules are then dried while being tumbled in a rotating drum at 50 to 300°C, and then calcined and carbonized. However, this method is complicated in that it uses powder as a raw material, requires the addition of a binder, and requires the granules to be treated by applying high heat after granulation, and the pin-type granulator is only described as being suitable for mass production (Patent Document 4).

[0007] One known method for producing granules using a pin-type granulator involves mixing and stirring powdered carbon black and granulation water inside the granulator while transporting them in the axial direction of the granulator, and then removing the granular carbon black from an outlet at the end of the granulator. This method is characterized by spraying granulation water in the direction opposite to the direction in which the carbon black is transported inside the granulator, with droplets of water sprayed to a diameter of 50 to 1000 μm. This method is known to result in 92% of the produced granules having a particle size of 1 mm or less (Patent Document 5). [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 8-183684 [Patent Document 2] Special Publication No. 6-79998 [Patent Document 3] Special Publication No. 3-75513 [Patent Document 4] Special Publication No. 6-45445 [Patent Document 5] Patent Publication No. 2004-182803 [Non-patent literature]

[0009] [Non-Patent Document 1] "Chapter 3: Current Status and Fertilizer Efficiency of Livestock Manure Compost," Guide to Proper Application of Livestock Manure Compost, pp. 19-27, March 2014, Published by the Okayama Prefectural Department of Agriculture, Forestry and Fisheries Summary of the Invention [Problem to be solved by the invention]

[0010] As livestock farms expand in scale, the amount of livestock manure and its compost is increasing, but using it as organic fertilizer directly poses many problems, such as the fact that consumption areas are far away and demand is concentrated in the spring, and there are also environmental hygiene issues such as odors during storage. Therefore, there is a need to develop technology to process these materials into organic fertilizers that have less odor and are high in the amount of active fertilizer ingredients such as nitrogen, phosphoric acid, and potassium salts. In particular, organic fertilizers made from cow manure have the problem of having low blending rates of phosphoric acid, nitrogen, potassium, etc.

[0011] Furthermore, conventional organic fertilizers made from livestock manure and other raw materials are mainly produced using a screw-type extrusion granulation method, which means that only large pellet-shaped organic fertilizers can be produced. When blended with chemical fertilizers with smaller particle sizes of 2 to 8 mm, there are problems such as the inability to spread the fertilizer on fields depending on the type of fertilizer spreader. Another drawback is that while chemical fertilizers are usually spherical, pellets are cylindrical, making them difficult to mix evenly. Even when other granulation methods are used, such as those using pin-type agitation granulators, which are suitable for producing small granules with a particle size of 1 mm or less, it is difficult to grow them to the size of chemical fertilizer granules. [Means for solving the problem]

[0012] The inventors have conducted extensive research into the production of granular organic fertilizers that have higher blending rates of phosphorus, nitrogen, potassium, etc. than the raw materials and have a shape equivalent to that of chemical fertilizers. As a result, they have confirmed that granular organic fertilizers that are odorless and rich in active ingredients can be obtained without using binders, coating agents, etc.

[0013] The present invention provides [1] A granular organic fertilizer having a particle size of 2 to 8 mm, which is made from organic raw materials of animal origin, and which is characterized in that the nitrogen content is 1.5 times or more that of the organic raw materials, the phosphorus content is 1.5 times or more that of the organic raw materials, and the potassium content is 1.3 times or more that of the organic raw materials. [2] The fertilizer according to [1], wherein the animal-derived organic raw material is livestock manure compost or livestock manure. [3] The organic fertilizer according to [1] or [2], characterized in that the nitrogen content is 1.5 to 4 times that of the organic raw material, the phosphorus content is 1.5 to 3.5 times that of the organic raw material, and the potassium content is 1.3 to 4 times that of the organic raw material. [4] The organic fertilizer according to [2], characterized in that the livestock manure compost or livestock excrement is cow manure compost or cow manure, and has a nitrogen content of 1.5 to 4.5%, a phosphorus content of 1.5 to 5%, and a potassium content of 2.5 to 6%. [5] The organic fertilizer according to [4], characterized in that the nitrogen content is 1.5 to 2.5%, the phosphorus content is 1.5 to 3%, and the potassium content is 3 to 5%. [6] The organic fertilizer according to [2], characterized in that the livestock manure compost or livestock excrement is swine manure compost or swine manure, and has a nitrogen content of 3 to 9%, a phosphorus content of 3 to 12%, and a potassium content of 2 to 7%. [7] The organic fertilizer according to [6], characterized in that the nitrogen content is 3 to 4.5%, the phosphorus content is 3 to 5%, and the potassium content is 2 to 5%. [8] The organic fertilizer according to [2], characterized in that the livestock manure compost or livestock excrement is chicken manure compost or chicken manure, and has a nitrogen component content of 3 to 9%, a phosphorus component content of 3 to 15%, and a potassium component content of 2 to 10%. [9] The organic fertilizer according to [8], characterized in that the nitrogen content is 4 to 6%, the phosphorus content is 3 to 5%, and the potassium content is 2.5 to 4%.

[10] A step of injecting an organic raw material of animal origin into a stirring and mixing granulator characterized by a pin shape to granulate it; A step of drying the granules obtained in the granulation step; and A process of separating the dried granules obtained in the drying process into granular organic fertilizers having a particle size of 2 to 8 mm using a sieve. A method for producing a granular organic fertilizer,

[11] The manufacturing method according to

[10] , wherein the moisture content of the animal-derived organic raw material is 50 to 64%.

[12] The manufacturing method according to

[11] , characterized in that the input amount of organic raw materials of animal origin is 1 ton / hour or less.

[13] The manufacturing method according to

[12] , characterized in that the rotation speed of the stirring and mixing granulator is 100 to 300 rpm.

[14] The manufacturing method according to

[13] , wherein the drying step is drying in the sun or using a dryer.

[15] The method according to

[14] , wherein the amount of dried granules rejected by sieving is 35% or less.

[16] The manufacturing method according to

[15] , wherein the animal-derived organic raw material is livestock manure compost or livestock manure.

[17] The manufacturing method according to any one of

[10] to

[16] , characterized in that the pin shape of the stirring and mixing granulator is such that a large number of pins of the same size are arranged spirally at equal intervals on the rotating shaft.

[18] A process of granulating an organic raw material of animal origin using an agitation mixer granulator characterized by having a large number of pins of the same size arranged spirally at equal intervals on a rotating shaft; A step of drying the granules obtained in the granulation step; and A process of separating the dried granules obtained in the drying process into granular organic fertilizers having a particle size of 2 to 8 mm using a sieve. Characterized in that it is produced from A method for producing an organic fertilizer, characterized in that the nitrogen content is 1.5 times or more that of the organic raw material, the phosphorus content is 1.5 times or more that of the organic raw material, and the potassium content is 1.3 times or more that of the organic raw material;

[19] A method for producing an organic fertilizer according to

[10] or

[18] , characterized in that the animal-derived organic raw material is cow dung or cow dung compost, and has a nitrogen content of 1.5 to 4.5%, a phosphorus content of 1.5 to 5%, and a potassium content of 2.5 to 6%.

[20] The method for producing an organic fertilizer according to

[10] or

[18] , characterized in that the animal-derived organic raw material is swine manure or swine manure compost, and has a nitrogen content of 3 to 9%, a phosphorus content of 3 to 12%, and a potassium content of 2 to 7%; and

[21] The method for producing an organic fertilizer according to

[10] or

[18] , characterized in that the animal-derived organic raw material is chicken manure or chicken manure compost, and has a nitrogen content of 3 to 9%, a phosphoric acid content of 3 to 15%, and a potassium content of 2 to 10%. Regarding. [Effects of the Invention]

[0014] The present invention provides a granular organic fertilizer that is odorless, rich in active ingredients, and can be mixed with chemical fertilizers and spread, and a method for producing the granular organic fertilizer. [Brief explanation of the drawings]

[0015] [Figure 1] Perspective view of the external and internal structure of a pin-type agitation mixer granulator [Figure 2] Vertical (A) and horizontal (B) views of the internal structure of a pin-type agitation mixer granulator [Figure 3] A diagram showing the relationship between the moisture content of cow manure compost raw material and the particle size distribution of the granulated material [Figure 4] Comparison photo of conventional granular product (pellets) and the product of this invention [Figure 5] The content (%) of nitrogen, phosphorus, and potassium (potassium) in the raw compost used in the production of this invention under various drying conditions and in the granular compost (granular organic fertilizer) that is the product of this invention [Figure 6] The concentration ratio of nitrogen, phosphorus, and potassium in the granular compost (granular organic fertilizer) that is the product of this invention compared to the raw compost used in the production of this invention under various drying conditions. DETAILED DESCRIPTION OF THE INVENTION

[0016] In the present invention, the organic raw material of animal origin refers to an organic substance produced and excreted by animals, which is usually used as a fertilizer, and preferably livestock manure or livestock manure compost can be used.

[0017] Examples of livestock manure include cow manure, pig manure, chicken manure, etc. The present invention is a technology that can handle the treatment of these livestock manures, and therefore any livestock manure raw material can be used to produce granular organic fertilizer, but since the blending ratios of phosphorus, nitrogen, potassium, etc. vary depending on the type of livestock, for example, chicken manure or pig manure is preferably used as the raw material to produce a fertilizer rich in phosphorus and nitrogen, and cow manure is preferably used as the raw material to produce a fertilizer rich in potassium. Compost is, for example, a material made by piling up organic materials, fermenting them, and then applying them to the soil and allowing them to decompose until they no longer cause damage to agricultural crops.

[0018] The organic fertilizers in this invention refer to organic fertilizers specified in the official specifications of the Act on Assurance of Fertilizer Quality, as well as sludge fertilizers and special fertilizers specified in the Act on Assurance of Fertilizer Quality. Examples of special fertilizers include animal excrement, ash from the combustion of animal excrement, compost, etc. In particular, with regard to special fertilizers, there is a notice from the Ministry of Agriculture, Forestry and Fisheries designating special fertilizers, etc., which specifies the specific fertilizers that can be used. For example, rice bran, fermented rice bran, vegetable oil cake and its powder (vegetable oil cake and its powder made from plant seed waste), herbaceous plant seed shell oil cake and its powder, nut oil cake and its powder (excluding kapok oil cake and its powder; the same applies below), coffee grounds, soybean waste and its powder (soybean waste or soybeans that have been deteriorated by wetting, etc., heated and then compressed, and its powder), tobacco waste fertilizer and its powder (excluding undenatured tobacco waste fertilizer powder), dried algae and its powder, cottonseed dregs fertilizer, mugwort dregs, wood ash (excluding earthen ash), charcoal fertilizer, clay residue, glue residue (excluding dried residue from extracting gelatin from ossein, and in the case of using raw materials derived from cattle, etc., only those for which control measures have been taken and those made from parts of cattle, etc. These include fertilizers manufactured in a process confirmed by the Minister of Agriculture, Forestry and Fisheries as not containing vertebrae, fish scales (excluding steamed fish scales and their powder), poultry processing waste fertilizer (excluding steamed feather meal (including steamed feathers)), fermented dried manure fertilizer (obtained by treating human waste with anaerobic fermentation), ash from the combustion of animal waste, compost (straw, rice husks, bark, animal waste and other organic matter of plant and animal origin (excluding sludge and fish and shellfish organs) piled or stirred and allowed to rot (including those using urea, ammonium sulfate and other materials that promote rot), and in the case of using raw materials derived from cattle, etc., only those that have undergone control measures have been implemented, and in the case of using parts of cattle, etc., only those manufactured in a process confirmed by the Minister of Agriculture, Forestry and Fisheries as not containing vertebrae, etc.) are permitted. In addition, organic fertilizers specified in official specifications and sludge fertilizers may be mixed with special fertilizers.

[0019] Organic fertilizers are generally converted into a form that can be utilized by plants and into a form that can be utilized by plants in the soil. In particular, the latter form is thought to be converted into a form that can be utilized by crops by being mineralized by the action of microorganisms in the soil.

[0020] The organic fertilizer of the present invention is a granular organic fertilizer with a particle size of 2 to 8 mm, and is circular rather than pellet-shaped. Because the organic fertilizer of the present invention has such a shape and size, it can be mixed with a chemical fertilizer and sprayed mechanically. While any method can be used to measure the particle size of the granular fertilizer, sieving is simple and preferred. The chemical fertilizer to be sprayed in combination with the organic fertilizer of the present invention refers to ordinary fertilizers defined in the Fertilizer Control Act, excluding organic fertilizers (including sludge compost). Nitrogen-based chemical fertilizers include ammonia-based fertilizers such as ammonium sulfate, ammonium chloride, and ammonium phosphate, which are produced using ammonia synthesized from atmospheric nitrogen as a raw material; nitrate-based fertilizers such as ammonium nitrate, calcium nitrate, and potassium nitrate; amide-based fertilizers such as urea and urea-aldehyde condensates; and calcium nitrate synthesized from atmospheric nitrogen. Compound fertilizers and compound fertilizers obtained by reacting or blending these fertilizers are also included in the chemical fertilizer of the present invention.

[0021] The organic fertilizer of the present invention is characterized by its improved three fertilizer elements compared to animal-derived organic raw materials, and is capable of supplying the soil with more of the three fertilizer elements from a compact granular fertilizer than animal-derived organic raw materials. The three fertilizer elements are nitrogen, phosphorus, and potassium.

[0022] Nitrogen is an essential element for plants, and is found in a variety of plant compounds, including the amino acids that make up proteins, the nucleic acid bases that make up nucleotides, the membrane lipid phosphatidylethanolamine, amino sugars such as glucosamine, and secondary metabolites such as alkaloids and lignin. Within the appropriate range, the more nitrogen a plant receives, the more chloroplasts it contains, and the higher its yield.

[0023] In the organic fertilizer of the present invention, the amount of nitrogen increases by 1.5 times or more, preferably 1.5 to 4 times, and more preferably 1.5 to 3 times, compared to the organic raw material.

[0024] Specifically, when cow manure is used as the raw material, the nitrogen content is 1.5 to 4.5%, preferably 1.5 to 3%, and more preferably 1.5 to 2.5%. When pig manure is used as the raw material, the nitrogen content is 3 to 9%, preferably 3 to 6%, and more preferably 3 to 4.5%. When chicken manure is used as the raw material, the nitrogen content is 3 to 9%, preferably 3 to 7%, and more preferably 4 to 6%.

[0025] Phosphate-containing plant compounds include nucleic acids, phospholipids that form cell membranes, adenosine triphosphate, the energy currency of living organisms, and ribulose-1,5-bisphosphate, which is involved in photosynthesis. Many proteins are phosphorylated and dephosphorylated by kinases and phosphatases, controlling reactions within the body. Because of these important functions in the body, phosphorus is important for plant growth, seed germination, and flowering.

[0026] In the organic fertilizer of the present invention, the amount of phosphoric acid increases by 1.5 times or more, preferably 1.5 to 3.5 times, and more preferably 1.5 to 3 times, compared to the organic raw material.

[0027] Specifically, when cow manure is used as the raw material, the phosphoric acid content is 1.5 to 5%, preferably 1.5 to 3.5%, and more preferably 1.5 to 3%. When pig manure is used as the raw material, the phosphoric acid content is 3 to 12%, preferably 3 to 8%, and more preferably 3 to 5%. When chicken manure is used as the raw material, the phosphoric acid content is 3 to 15%, preferably 3 to 8%, and more preferably 3 to 5%.

[0028] Unlike other macronutrients, potassium does not become a component of metabolic biomolecules in plants, but rather functions as an inorganic salt dissolved in plant fluids. When potassium ions move through ion channels to other cells, the water potential of those cells decreases, causing water movement. Plants maintain a lower water potential in their leaves relative to the rhizosphere, and water absorption relies on this difference. In komatsuna and spinach, there is a positive correlation between the amount of water and potassium content per dry weight of leaves. Potassium also activates plant enzymes, promoting carbohydrate and protein synthesis, regulating water content within the plant, and the synthesis of chlorophyll precursors required for photosynthesis. It also determines fruit color and shape and increases Brix sugar content. Therefore, potassium-rich soils produce high-quality fruit.

[0029] In the organic fertilizer of the present invention, potassium is increased by 1.3 times or more, preferably 1.3 to 4 times, and more preferably 1.3 to 3 times, compared to the organic raw material.

[0030] Specifically, when cow manure is used as the raw material, the potassium content is 2.5 to 6%, preferably 2.5 to 5%, and more preferably 3 to 5%. When pig manure is used as the raw material, the potassium content is 2 to 7%, preferably 2 to 5%. When chicken manure is used as the raw material, the potassium content is 2 to 10%, preferably 2 to 7%, and more preferably 2.5 to 4%.

[0031] In the method for producing a granular organic fertilizer of the present invention, the step of injecting an animal-derived organic raw material into an agitation mixer granulator characterized by a pin shape to granulate the raw material comprises the steps of preparing the animal-derived organic raw material and injecting it into the agitation mixer granulator characterized by a pin shape, and granulating the animal-derived organic raw material injected into the granulator.

[0032] The animal-derived organic raw material used in the production method of the present invention has the same meaning as above, and refers to organic substances produced and excreted by animals that are usually used as fertilizers, preferably livestock manure or livestock manure compost.

[0033] Examples of livestock manure include cow manure, pig manure, chicken manure, etc. The present invention is a technology that can handle the treatment of these livestock manures, and therefore any livestock manure raw material can be used to produce granular organic fertilizer, but since the blending ratios of phosphorus, nitrogen, potassium, etc. vary depending on the type of livestock, for example, chicken manure or pig manure is preferably used as the raw material to produce a fertilizer rich in phosphorus and nitrogen, and cow manure is preferably used as the raw material to produce a fertilizer rich in potassium. Compost is, for example, a material made by piling up organic materials, fermenting them, and then applying them to the soil and allowing them to decompose until they no longer cause damage to agricultural crops.

[0034] Organic raw materials of animal origin should have a moisture content of 50-64%, preferably 58-64% when using cow manure or cow manure compost, and 52-64% when using chicken manure compost or pig manure compost. For organic raw materials of animal origin with low moisture content, water can be added to adjust the moisture content to 50-64%, and for raw materials with a moisture content of 64% or more, the moisture content can be adjusted by heating or other methods. The raw materials adjusted in this way are then fed into a granulator.

[0035] The feeding rate is preferably 2 ton / hour or less, more preferably 1 ton / hour or less, and even more preferably 0.5 ton / hour or less.

[0036] The stirring / mixing granulator characterized by the pin shape in the present invention is preferably a granulator having a structure in which a large number of pins of the same size are arranged spirally and at equal intervals on the rotating shaft of the stirring / mixing granulator. As a specific example, the stirring / mixing granulator shown in Figure 1, which shows a perspective view of the internal structure and external structure, and Figure 2, which shows the vertical (A) and horizontal (B) views of the internal structure, is shown, in which pin-shaped protrusions are arranged spirally on the rotating shaft. The pins are all the same shape and are arranged at equal intervals.

[0037] The granulation temperature is 20°C to 60°C, and the granulation humidity is 80% or higher. The rotation speed needs to be adjusted depending on the motor output of the granulator, but granulation can be carried out at, for example, 100 to 300 rpm, preferably 150 to 300 rpm, and more preferably 180 to 260 rpm. The resulting granules are sized using a size sizing machine, if necessary.

[0038] In the method for producing a granular organic fertilizer of the present invention, the step of drying the granules obtained in the granulation step refers to a step of evaporating the moisture from the granules obtained in the granulation step by natural sun drying or using a dryer.

[0039] Natural sun drying is a device that uses natural energy, such as solar energy and wind, to dry out the moisture in compost. For small amounts of compost, granular organic compost can be piled in trays in a plastic greenhouse to a depth of about 2-4 cm and allowed to dry for 4-10 days. For larger scale composting facilities, it is preferable to install a fan or other fan in the greenhouse to expedite drying and to install a self-propelled agitator to ensure uniform drying. Under these conditions, drying can be carried out for 7-30 days, preferably 10-17 days.

[0040] Drying using a dryer can be done using any type of dryer used for industrial purposes, such as a rotary drum dryer, a rotary triple screw dryer, or a rotary kiln, as long as it is used to dry large amounts of granules. A rotary kiln is preferred. The drying temperature and time vary depending on the amount of granules to be treated, but for approximately 15 kg of granules, heating at a temperature of 150°C to 250°C for 15 to 80 minutes, preferably at a temperature of 180°C to 220°C for 20 to 50 minutes, will suffice.

[0041] At the end of the drying process, granules that do not meet the particle size standard of 2 to 8 mm for granular organic fertilizer account for 35% or less, preferably 25% or less, of the total granules. These non-standard granules can be removed by sieving. Specifically, the dried granules can be sieved in a sieving machine that complies with the sieving test method of the Japanese Industrial Standards to produce a circular granular organic fertilizer with a particle size of 2 to 8 mm.

[0042] Industrially, sieving machines are mainly divided into vibrating and rotary types. Vibrating sieves sift the input materials by vibrating a sieve mesh up and down. There may also be multiple sieve meshes, allowing for step-by-step sieving. Rotary sieves are also called trommels, and sift the input materials by rotating a cylindrical sieve. Another advantage is that because the input materials are sieved inside the machine, they are quieter than vibrating screens.

[0043] The method for producing a granular organic fertilizer of the present invention provides a granular organic fertilizer that uses organic raw materials of animal origin and has a particle size of 2 to 8 mm, and that has a nitrogen content of 1.5 times or more that of the organic raw materials, a phosphorus content of 1.5 times or more that of the organic raw materials, and a potassium content of 1.3 times or more that of the organic raw materials.

[0044] In the granular fertilizer obtained by the manufacturing method of the present invention, the three major elements of the fertilizer change as follows.

[0045] (1) The nitrogen content increases by 1.5 times or more, preferably 1.5 to 4 times, more preferably 1.5 to 3 times, compared to the organic raw material. Specifically, when cow manure is used as the raw material, the nitrogen content is 1.5 to 4.5%, preferably 1.5 to 3%, and more preferably 1.5 to 2.5%. When pig manure is used as the raw material, the nitrogen content is 3 to 9%, preferably 3 to 6%, and more preferably 3 to 4.5%. When chicken manure is used as the raw material, the nitrogen content is 3 to 9%, preferably 3 to 7%, and more preferably 4 to 6%.

[0046] (2) The amount of phosphoric acid increases by 1.5 times or more, preferably 1.5 to 3.5 times, more preferably 1.5 to 3 times, compared to the amount of the organic raw material. Specifically, when cow manure is used as the raw material, the phosphoric acid content is 1.5 to 5%, preferably 1.5 to 3.5%, and more preferably 1.5 to 3%. When pig manure is used as the raw material, the phosphoric acid content is 3 to 12%, preferably 3 to 8%, and more preferably 3 to 5%. When chicken manure is used as the raw material, the phosphoric acid content is 3 to 15%, preferably 3 to 8%, and more preferably 3 to 5%.

[0047] (3) The amount of potassium increases by 1.3 times or more, preferably 1.3 to 4 times, more preferably 1.3 to 3 times, compared to the amount of the organic raw material. Specifically, when cow manure is used as the raw material, the potassium content is 2.5 to 6%, preferably 2.5 to 5%, and more preferably 3 to 5%. When pig manure is used as the raw material, the potassium content is 2 to 7%, preferably 2 to 5%. When chicken manure is used as the raw material, the potassium content is 2 to 10%, preferably 2 to 7%, and more preferably 2.5 to 4%. [Example]

[0048] Example 1 Using cow manure compost produced on a farm as the organic raw material, the following production study was carried out using a stirring and mixing granulator (manufactured by Zhangjiagang MG Machinery Co., Ltd.) with pin-shaped protrusions arranged spirally on the rotating shaft, the internal and external structures of which are shown in perspective in Figure 1 and the internal structure shown in vertical (A) and horizontal (B) views in Figure 2.

[0049] (1) Preliminary test of the relationship between the amount of organic raw material input and the particle size of the granulated material Using organic raw material made from cow manure compost, the relationship between the amount of organic raw material fed into a granulator and the particle size of the granules was confirmed. The relationship between the amount fed and particle size was examined under conditions of a rotation speed of 213 rpm, a granulation temperature of 37-41°C, and a granulation humidity of 96-99%RH. At a feed rate of 1.5 tons / hour, more than 50% of the particles were 2 mm or smaller in diameter. At a feed rate of 1 ton / hour, the rate of fine particles 2 mm or smaller in diameter was approximately 35%, and at a feed rate of 0.5 tons / hour, the rate of fine particles 2 mm or smaller in diameter fell to less than 30%.

[0050] (2) Preliminary test of the relationship between the rotation speed of the granulator and the particle size of the granulated material We investigated the relationship between the rotation speed of a granulator and the particle size of the granules when using organic raw materials made from cow manure compost.The rotation speed was examined under conditions of a granulation temperature of 38-42°C, a granulation humidity of 96-99% RH, and a dosage of 1 ton / hour.The results showed that at a rotation speed of 235 rpm, fine particles with a particle size of 2 mm or less accounted for approximately 35%, and granules with a particle size of 8 mm or more accounted for approximately 10%.However, when the rotation speed was reduced to 213 rpm, fine particles with a particle size of 2 mm or less remained at approximately 35%, but granules with a particle size of 8 mm or more decreased to approximately 1%.

[0051] (3) Relationship between moisture content of organic raw materials and particle size of granulated material Cow manure compost, which has a slightly different viscosity than chicken manure compost and swine manure compost, was used as an organic raw material. The moisture content of the compost varied from 56% to 65%. The granulation was carried out under the following conditions (granulator rotation speed: 213 rpm, input rate: 1.0 ton / hour, granulation temperature: 23°C to 42°C, granulation humidity: 94% to 99% RH). The relationship between moisture content and particle size distribution of the resulting granular fertilizer was examined. The results are shown in Figure 3.

[0052] The results in Figure 3 confirm that when cow manure compost is used, granular organic fertilizer with a particle size of 2 to 8 mm can be produced at a rate of nearly 70% when the moisture content of the organic raw material is above 58% and below 64%.

[0053] In the production of organic fertilizer using conventional extrusion granulation methods, the moisture content of the organic raw materials needs to be reduced to approximately 30 to 40%, and therefore the moisture in the organic raw materials needs to be evaporated by heating (Patent Document 1, Patent Document 3). However, the production method of the present invention does not require heating, and it has been confirmed that this is useful for reducing production costs and preventing unpleasant odors.

[0054] The granules obtained in the granulation step were dried in the sun until all moisture was removed, and granular organic fertilizer with a particle size of 2 to 8 mm was collected using a standard sieve mesh specified in JIS_Z8801.

[0055] Figure 4 shows a photograph comparing the shapes of the obtained granular organic fertilizer and the organic fertilizer pellets obtained by the conventional extrusion granulation method.

[0056] From the comparison photographs in FIG. 4, it can be seen that the granular organic fertilizer of the present invention has a shape and size that allows it to be mixed with chemical fertilizers, and is in a form that is suitable for spreading on fields by machine.

[0057] Furthermore, the odor of the granular fertilizer of the present invention was significantly improved compared to that of the conventional fertilizer produced from cow dung compost.

[0058] Example 2 (Production of granular organic fertilizer using cow dung compost as a raw material) Using cow manure compost with a moisture content of 62% as the raw material, organic fertilizer was granulated using the same granulator as used in Example 1 under the following conditions: granulator rotation speed 213 rpm, raw material input rate 1.0 ton / hour, granulation temperature 14.6°C, granulation humidity 92.2% RH (temperature and humidity logger: SK-L754, SKL-754 sensor: SK-L754-2, manufactured by Sato Keiryoki Seisakusho Co., Ltd.).

[0059] The granules obtained by the granulation process were divided into four groups, A to D, to investigate the influence of the drying method. Samples A and B were dried in the sun, and samples C and D were dried using a dryer. Samples A and B were stored in a greenhouse for 8 days to produce granular fertilizer samples A and B. Sample C was produced by drying 16 kg of granules at 200°C for 40 minutes using a rotary kiln (manufactured by Zhangjiagang MG Machinery Co., Ltd.) as the dryer, producing granular fertilizer sample C. Sample D was produced by drying 16 kg of granules at 200°C for 20 minutes using a rotary kiln (manufactured by Zhangjiagang MG Machinery Co., Ltd.).

[0060] The content of nitrogen, phosphorus, and potassium, which are active ingredients in fertilizer, was measured for the obtained granular fertilizer and the cow manure compost used as a raw material. The measurement method was as follows, in accordance with the Fertilizer Testing Methods (2021) of the Agriculture, Forestry and Fisheries Materials Inspection Center (FAMIC).

[0061] The nitrogen content was measured by adding sulfuric acid, potassium sulfate, and copper (II) sulfate pentahydrate to the analytical sample, pretreating it using the Kjeldahl method to convert all nitrogen to ammonium ions, adding sodium hydroxide solution, and steam distilling it. The separated ammonia was collected with sulfuric acid, and the excess sulfuric acid was titrated (neutralized) with sodium hydroxide solution to determine the total nitrogen content in the analytical sample using the Kjeldahl method (4.1.1.a).

[0062] The phosphate content was measured by the ammonium vanadomolybdate spectrophotometric method (4.2.1.a), in which sulfuric acid, potassium sulfate, and copper (II) sulfate pentahydrate were added to the analytical sample, followed by Kjeldahl digestion to convert total phosphorus to phosphate ions, and the absorbance of the phosphorus vanadomolybdate produced by reaction with ammonium vanadate (V), hexaammonium heptamolybdate, and nitric acid was measured to determine the total amount of phosphate in the analytical sample.

[0063] The potassium content was measured by flame photometry (4.3.1.a), in which the analytical sample was pretreated by ashing and boiling in hydrochloric acid to convert all potassium to potassium ions, and the intensity of the emission line at a wavelength of 766.5 nm generated in the flame was measured to determine the total amount of potassium in the analytical sample. The results are shown in Table 1 and Figure 5.

[0064] [Table 1]

[0065] From the results in Table 1 and Figure 5, it can be seen that the nitrogen content of the raw compost was 0.91%, but increased to 2.31% and 2.24% in sun-dried Samples A and B, respectively, while Sample C obtained by mechanical drying had a nitrogen content of 2.03%, and Sample D had a nitrogen content of 1.79%, both of which were approximately or more than double. This confirmed that the nitrogen content was significantly higher than the 1.1% of the known cow manure compost described in Non-Patent Document 1.

[0066] Regarding the phosphorus content, the nitrogen content, which was 0.98% in the raw compost, increased to 2.65% and 2.37% in sun-dried samples A and B, respectively, while sample C obtained by mechanical drying increased to 2.28% and sample D increased to 1.94%, both of which increased by approximately to more than two times. This confirmed that the phosphorus content was significantly higher than the 1.1% phosphorus content of the known cow manure compost described in Non-Patent Document 1.

[0067] Furthermore, the potassium content of the raw compost was 1.97%, but increased to 4.6% and 4.23% in sun-dried samples A and B, respectively, while sample C obtained by mechanical drying had a potassium content of 3.7%, and sample D had a potassium content of 3.17%, both of which were approximately 1.5 times higher. This confirmed that the potassium content was significantly higher than the 2.1% of the known cow manure compost described in Non-Patent Document 1.

[0068] To confirm the effect of concentrating the relative component contents, the relative values ​​of the nitrogen, phosphate, and potassium components of each sample A, B, C, and D to the raw compost were calculated, assuming that the nitrogen, phosphate, and potassium components of the raw compost were 1. The results are shown in Table 2 and Figure 6.

[0069] [Table 2]

[0070] According to Table 2 and Figure 6, the granular organic fertilizers obtained by the manufacturing method of the present invention, Sample D, dried at 200°C for 40 minutes, had 1.97 times the nitrogen, 1.98 times the phosphorus, and 1.61 times the potassium of the raw compost, while Sample C, dried at 200°C for 20 minutes, had 2.23 times the nitrogen, 2.33 times the phosphorus, and 1.88 times the potassium of the raw compost. In comparison, the sun-dried granular organic fertilizers, Sample B, had 2.46 times the nitrogen, 2.42 times the phosphorus, and 2.15 times the potassium of the raw compost, while Sample A had 2.54 times the nitrogen, 2.71 times the phosphorus, and 2.34 times the potassium of the raw compost, meaning that all of the fertilizer's main active ingredients were more than double those of the raw compost.

[0071] Example 3 (Production of granular organic fertilizer using chicken manure compost) Poultry manure compost with a moisture content of 52.7% was used as the raw material, and granulation was carried out using the same granulator as used in Example 1 under the following conditions: granulator rotation speed 213 rpm, raw material input rate 1.0 ton / hour, granulation temperature 37.0°C, granulation humidity 98.0% RH (temperature and humidity logger: SK-L754, SKL-754 sensor: SK-L754-2, manufactured by Sato Keiryoki Seisakusho Co., Ltd.).

[0072] The granules obtained from the granulation process were dried in the sun (stored in a greenhouse for 8 days) to obtain granular fertilizer. It was visually observed that approximately 60-70% of the granulated fertilizer had been produced, with a size of 2-8 mm. The content of the active ingredients in the fertilizer, nitrogen, phosphorus, and potassium, was measured for the resulting granular fertilizer and the chicken manure compost used as the raw material. The measurement method was as follows, in accordance with the Fertilizer Testing Methods (2021) of the Food and Agricultural Materials Inspection Center (FAMIC).

[0073] The nitrogen content was measured by adding sulfuric acid, potassium sulfate, and copper (II) sulfate pentahydrate to the analytical sample, pretreating it using the Kjeldahl method to convert all nitrogen to ammonium ions, adding sodium hydroxide solution, and steam distilling it. The separated ammonia was collected with sulfuric acid, and the excess sulfuric acid was titrated (neutralized) with sodium hydroxide solution to determine the total nitrogen content in the analytical sample using the Kjeldahl method (4.1.1.a).

[0074] The phosphate content was measured by the ammonium vanadomolybdate spectrophotometric method (4.2.1.a), in which sulfuric acid, potassium sulfate, and copper (II) sulfate pentahydrate were added to the analytical sample, followed by Kjeldahl digestion to convert total phosphorus to phosphate ions, and the absorbance of the phosphorus vanadomolybdate produced by reaction with ammonium vanadate (V), hexaammonium heptamolybdate, and nitric acid was measured to determine the total amount of phosphate in the analytical sample. The results are shown in Table 3.

[0075] [Table 3]

[0076] Compared to cow manure, chicken manure is rich in nitrogen and phosphorus at the raw compost stage, but when it is made into granular fertilizer, these components are further concentrated, with extremely high contents of 5.04% nitrogen and 3.84% phosphorus. Potassium was 1.58% in chicken manure raw compost compared to 1.97% in cow manure compost, but this increased to 3.33% when made into granular fertilizer.

[0077] To confirm the effect of concentrating the relative component contents, the relative values ​​of the nitrogen, phosphorus, and potassium components of the granular chicken manure fertilizer to the raw compost were calculated, assuming that the nitrogen, phosphorus, and potassium components of the raw compost were set to 1, and the results are shown in Table 4.

[0078] [Table 4]

[0079] It was confirmed that the granular fertilizer was 1.95 to 2.11 times more concentrated than the other components, and that a granular fertilizer rich in nitrogen and phosphorus was produced that took advantage of the characteristics of the chicken manure compost raw material.

[0080] Example 4 (Production of granular organic fertilizer using pig manure compost as a raw material) Pig manure compost with a moisture content of 53.2% was used as the raw material, and granulation was carried out using the same granulator as used in Example 1 under the following conditions: granulator rotation speed 213 rpm, input rate 1.0 ton / hour, granulation temperature 37.5°C, granulation humidity 98.9% RH (temperature and humidity logger: SK-L754, SKL-754 sensor: SK-L754-2, manufactured by Sato Keiryoki Seisakusho Co., Ltd.). It was visually confirmed that approximately 70% of the granulated fertilizer had been produced, with a particle size of 2 to 8 mm. The granules obtained from the granulation process (same as for cow manure compost) were naturally dried in the sun.

[0081] The content of the active ingredients in the fertilizer, nitrogen, phosphorus, and potassium, was measured for the resulting granular fertilizer and the pig manure compost used as the raw material. The measurement method was as follows, in accordance with the Fertilizer Testing Methods (2021) of the Agriculture, Forestry and Fisheries Materials Inspection Center (FAMIC).

[0082] The nitrogen content was measured by adding sulfuric acid, potassium sulfate, and copper (II) sulfate pentahydrate to the analytical sample, pretreating it using the Kjeldahl method to convert all nitrogen to ammonium ions, adding sodium hydroxide solution, and steam distilling it. The separated ammonia was collected with sulfuric acid, and the excess sulfuric acid was titrated (neutralized) with sodium hydroxide solution to determine the total nitrogen content in the analytical sample using the Kjeldahl method (4.1.1.a).

[0083] The phosphate content was measured by the ammonium vanadomolybdate spectrophotometric method (4.2.1.a), in which sulfuric acid, potassium sulfate, and copper (II) sulfate pentahydrate were added to the analytical sample, followed by Kjeldahl digestion to convert total phosphorus to phosphate ions, and the absorbance of the phosphorus vanadomolybdate produced by reaction with ammonium vanadate (V), hexaammonium heptamolybdate, and nitric acid was measured to determine the total amount of phosphate in the analytical sample.

[0084] The potassium content was measured by flame photometry (4.3.1.a), where the analytical sample was pretreated by ashing and boiling in hydrochloric acid to convert all potassium to potassium ions, and the intensity of the emission line at a wavelength of 766.5 nm generated in the flame was measured to determine the total amount of potassium in the analytical sample. The results are shown in Table 5.

[0085] [Table 5]

[0086] Compared to cow manure, pig manure is also rich in nitrogen and phosphorus at the raw compost stage, but when it is made into granular fertilizer, these components are further concentrated, with extremely high contents of 3.99% nitrogen and 3.81% phosphorus. Potassium was 1.34% in pig manure raw compost compared to 1.97% in cow manure compost, but this increased to 2.69% when made into granular fertilizer.

[0087] To confirm the effect of concentrating the relative component contents, the relative values ​​of the nitrogen, phosphorus, and potassium components of the granular swine manure fertilizer to the raw compost were calculated, assuming that the nitrogen, phosphorus, and potassium components of the raw compost were set to 1, and the results are shown in Table 6.

[0088] [Table 6]

[0089] It was confirmed that the granular fertilizer was enriched with each component by 1.84 to 2.05 times, and that a granular fertilizer rich in nitrogen and phosphorus was produced that took advantage of the characteristics of the pig manure compost raw material.

[0090] As described above, in a method for producing organic fertilizer using animal-derived organic raw materials, it was confirmed that by granulating using an agitation / mixing granulator characterized by a large number of pins of the same size arranged at equal intervals in a spiral, it is possible to produce a granular fertilizer that is easy to blend with chemical fertilizers, unlike conventional organic fertilizers. Furthermore, by examining the moisture content of the animal-derived organic raw materials, it was confirmed that it is possible to produce granules containing 65% or more of granular organic fertilizer with particle sizes of 2 to 8 mm that are easy to blend with chemical fertilizers, and it was confirmed that this manufacturing method has high product production efficiency.

[0091] Furthermore, the granular organic fertilizer with a particle size of 2 to 8 mm obtained by this production method contained more than twice the amount of nitrogen, phosphorus, and potassium, the three major components of fertilizer, and was expected to have significantly superior fertilizing effects. It also had less of the odor characteristic of organic fertilizers than conventional organic fertilizers. In particular, cow manure fertilizer, which has traditionally been known to accumulate in soil but is said to contain fewer of the three major elements than other livestock, was confirmed to be a beneficial fertilizer without these drawbacks. [Explanation of symbols]

[0092] 1. Granulator 2. Rotation axis 3.Inlet 4.Outlet 5. Pin 6. Screw blade 7. Flanges 8. Motor

Claims

1. A granular organic fertilizer that is made from cow dung compost or cow dung raw material (excluding those containing other fertilizer components) and has a particle size of 2 to 8 mm, is circular rather than pellet-shaped, and is characterized by having a nitrogen content that is 1.5 times or more that of the cow dung compost or cow dung raw material, with a component content of 1.5 to 2.5%, a phosphorus content that is 1.5 times or more that of the cow dung compost or cow dung raw material, with a component content of 1.5 to 3%, and a potassium content that is 1.3 times or more that of the cow dung compost or cow dung raw material, with a component content of 3 to 5%.

2. An organic fertilizer as described in claim 1, characterized in that the component contents are 1.79 to 2.5% for nitrogen, 1.94 to 3% for phosphorus, and 3.17 to 5% for potassium.

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