JPH04317485A - Granulating method of granular fertilizer - Google Patents

Abstract

PURPOSE:To efficiently produce the good-quality granulated material of granular fertilizer at >=80% granulation yield without using a granulation auxiliary such as blackstrap molasses even when abundant organic raw materials generally difficult in granulation are used. CONSTITUTION:In a granulating method for granular fertilizer, it is a feature that the granulated material having 1-4mm particle diameter is produced by a first and second step stages described below. In the first step stage, the powder of an inorganic raw material is incorporated into the powder of an organic raw material. The obtained powder of both raw materials is supplied to a granulator without using a granulation auxiliary and particle nucleuses are formed. In the second step stage, these particle nucleuses are continuously supplied to the other granulator and the granulated material is grown and sized.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a method for granulating granular fertilizer using organic raw materials as the main raw material, and more specifically to a method for granulating granular fertilizer using a two-stage granulation method in which a granulator is divided into two stages. It concerns the grain method.

0002

[Prior Art] The granulation method for granular fertilizer that uses organic matter as a raw material is generally the same as for granular inorganic fertilizer that does not contain organic matter, by mixing powdered raw materials, adding granulation water, and adding waste molasses or the like if necessary. Granulation is performed using a granulation aid. On this occasion,
As the granulator, a rolling granulator such as a paddle type, pan type, or drum type is generally used. According to this method, as the proportion of organic matter in the product increases, the granulation yield deteriorates, so the proportion is limited to 60% at most. Furthermore, in order to produce products with a high proportion, granulation aids such as blackstrap molasses must be used. This not only reduces the fertilizer content of the product, but also causes coloration and bad odor to the product, which has the disadvantage of lowering its commercial value and increasing cost. In addition, there is a method of using an extrusion granulator to increase the mixing ratio of organic raw materials, but because the equipment and operating costs per processing amount are high, it is not economical for mass production such as fertilizer. Not on point. Furthermore, because the product is cylindrical in shape, it is not suitable for mechanical fertilization.

0003

[Problem to be solved by the invention] A high-strength granular fertilizer without problems of coloring or bad odor can be produced from raw materials with a high organic content, which was previously considered impossible, without using granulation aids such as molasses. To provide a method for efficiently manufacturing.

0004

[Means for Solving the Problems] As a result of intensive research in view of the above problems, the present inventors have determined that organic raw materials are
After finely pulverizing, these raw material powders are used in the first stage process to form agglomerated particle nuclei, which are then used in a second stage process to grow and size the particles using another granulator. The present invention was achieved by discovering that by granulating, it is possible to economically granulate raw materials containing large amounts of organic raw materials with poor granulation properties without using granulation aids. .

[0005] That is, the present invention involves supplying a raw material powder, which is an organic raw material powder containing an inorganic raw material powder, to a granulator to form particle nuclei without using any granulation aids other than water or steam. The first stage step is to continuously supply the particle cores to another granulator, and the second step is to granulate, grow and size the particles.
The present invention relates to a method for granulating a granulated product having a particle size of 1 to 4 mm through a step process, and the granulation yield reaches 80% by weight or more.

The granulator used in the present invention is a stirring type vertical granulator, a rolling type plate granulator, a drum type granulator, a paddle type granulator, etc. Granulators have lower equipment costs per throughput and lower operating costs than other granulators such as extrusion-type granulators and compression-type granulators, and are widely used for mass production. It is something.

[0007] The granulation mechanism using these stirring type or rolling type granulators can be divided into a nucleation stage, a growth stage, and a completion stage. In this nucleation stage, the powder raw material input into the granulator is mixed with the liquid given in advance or inside the granulator, and discontinuously occurs around the contact points between the powder constituent particles. By creating concave lens-shaped liquid bridges, initially loose aggregates are formed, but when this is rolled, the aggregates gradually become tighter and the voids between the particles are reduced. Since the liquid is still scattered locally, if it comes into contact with small pieces, it easily adheres and bonds to form larger aggregates. This is the nucleation stage.

[0008] During the growth stage of the nuclei produced in this way, if the liquid in the gaps between the particles is in an appropriate amount and distributed almost evenly in the gaps, the granules will have plasticity and there will be no excess liquid film on the surface. As long as it collides with other smaller granules, it will transform itself and embrace the opponent, or if the opponent is weak, it will destroy it and knead the fragments into its own surface, becoming one. It is further rolled to become spherical. When colliding with granules of similar size and strength, objects may be exchanged due to friction on their mutual surfaces. By repeating this phenomenon, the granules gradually undergo rolling compaction and become stronger. This is the growth stage.

[0009] In the next stage, at the completion stage, when the supply of liquid is stopped, the excess liquid content of the granules is used up for growth, the liquid content between the particles decreases, and the liquid flows from the surface of the granules to the inside. Due to the increased retraction surface capillary force, it becomes a so-called "surface dry granule" which has a stronger internal bonding force than a granule with a high liquid content. Furthermore, when the liquid content is reduced by rolling along with natural evaporation or forced drying, there is no longer a liquid film on the surface of the granules, which hardly deforms itself even when it collides with other objects, and also has no ability to absorb other objects. The particles disappear and the growth of the granules stops. In other words, it is at the completion stage.

Conventionally, these series of granulation mechanisms were carried out in the same granulation machine, but in this granulation mechanism, aggregates formed in the nucleation stage are taken out and used in the growth stage and completion stage. By using a two-stage granulation method in which granulation is performed using another granulator, organic raw materials with weak bonding strength between particles can be efficiently granulated using only granulation water or steam, without using granulation aids. It became possible to make grains.

[0011] In the present invention, organic raw materials are those listed in the official standards for ordinary fertilizers established based on the provisions of Article 3 and the proviso to Article 25 of the Fertilizer Control Law (Act No. 127 of 1950). These include fish cake powder, dried fish fertilizer powder,
Boiled fish cake scraps, crustacean fertilizer powder, steamed fish scales and their powder, meat scraps powder, meat and bone meal, steamed carcass horn powder, steamed carcass horn and bone meal, steamed hair meal, dried blood and its powder, raw bone meal, steamed bone meal, Steamed leather powder, dried silkworm pupa powder, silkworm pupa oil cake and its powder, silk-spun silkworm pupa waste, soybean oil cake and its powder, rapeseed oil cake and its powder, cotton oil cake and its powder, peanut oil cake and its powder, linseed oil Kapok rice cake and its powder, sesame oil cake and its powder, castor oil cake and its powder, rice bran oil cake and its powder, other herbaceous vegetable oil cake and its powder, kapok oil cake and its powder, corn bud oil cake and its powder, Tobacco waste fertilizer powder, licorice residue powder, tofu residue dry fertilizer, citrus lees powder, nitrogenous guano, processed manure fertilizer, fish waste processing fertilizer, dried bacterial cell fertilizer, by-product animal fertilizer, by-product vegetable fertilizer, It is a mixed organic fertilizer.

[0012] In the present invention, the granulator used in the first step of granulation is a stirring type or rolling type granulator. In the granulation method, as the first step, the pulverized organic raw material is fed to a granulator in order to create agglomerated granulation nuclei, and is mixed and mixed in a wet state while spraying water or steam necessary for granulation. to obtain an aggregate of

[0013] Next, in the second stage step, the agglomerate (wet) obtained as described above is transferred to a rotary granulator other than that used in the first stage step, such as a drum type granulator. The granules are fed to a machine and grown and sized while adding water, steam, etc. necessary for granulation.

The granulation method of the present invention is as described above, and therefore, the mechanical strength such as hardness of the agglomerated granules forming the core formed in the first step is not so important. 1st
The wet agglomerates obtained in the step process can be processed in any granulator in the second step, for example, in a drum type granulator, by supplying some water for granulation or, if necessary, steam, etc. Since the agglomerates are stirred or rolled, they can be efficiently formed into particles with high strength and uniform particle size without adding a granulation aid. It has sufficient mechanical strength that it does not disintegrate even after being supplied and dried, and even in actual manufacturing, the product size is 1 to 1.
It is possible to obtain spherical granular fertilizer with a 4 mm granulation yield of 80% by weight or more at a high yield.

[0015]

[Examples] The present invention will be explained in detail by examples below, but the present invention is not limited to the examples unless it departs from the gist of the present invention. [Example 1] Powder raw materials (4 kg in total) containing 36 parts by weight of steamed bone meal, 30 parts by weight of castor meal, 14 parts by weight of animal fertilizer, 4 parts by weight of ammonium sulfate, 4 parts by weight of urea, and 12 parts by weight of potassium sulfate were used. Rotates at 300 rpm, inner diameter 35 cm, depth 3
The mixture was supplied to a 5 cm vertical stirring granulator, and granulation operation (primary granulation) was performed for about 8 minutes while adding granulation water. Approximately half of the obtained aggregated wet granular material was air-dried and sieved using a 5-mesh and 16-mesh Tyler standard sieve to obtain granules with a product size of 5 to 16 mesh (particle size 1 to 4 mm),
The weight percent of the product size relative to the total dry granules was determined as the product yield. The remaining wet particulate material had an inner diameter of 76.3 cm;
The mixture was supplied to a pan-shaped granulator with a depth of 19 cm, and granulation operation (secondary granulation) was performed at a rotation speed of 23 rpm for 3 to 5 minutes while adding granulation water. A part of the obtained granular secondary granulated product was collected, and the inner diameter was 38cm.
m, length 250cm rotary dryer with 5 rotations.
rpm, inlet hot air temperature 230℃, outlet hot air temperature 110℃
℃, outlet temperature of 80℃, and its water content (wt%)
), product yield (wt%), and hardness (by Kiya hardness tester)
kg) was calculated. The results are shown in Table 1. The moisture content of each raw material used was 4.0% by weight of steamed bone powder, 1% of castor meal,
0.0% by weight, by-product animal fertilizer 10.0% by weight, ammonium sulfate 0
．． 2% by weight, urea 0.3% by weight, potassium sulfate 0.2% by weight
Met. (Method for Measuring Moisture) Accurately place 2 to 5 g of an analytical sample in a flat weighing bottle (diameter 5 cm, height 3 cm), dry at 75° C. for 5 hours, weigh accurately, and take the weight loss as moisture. (Hardness measurement method) Measuring device: Kiya type hardness meter Measuring method: Sample 1 with a particle size that is about the average of the particle size distribution
0 to 20 grains are arbitrarily taken out and measured using a grain hardness meter, and the average value is defined as the hardness (Kg/grain) (according to Zen-Noh Standards: Method for measuring hardness of granular fertilizers).

[0016]

[Table 1]

[Example 2] Powder raw materials of 40 parts by weight of rapeseed meal, 30 parts by weight of steamed bone meal, 20 parts by weight of processed fish waste fertilizer and 10 parts by weight of phosphoric acid powder (5 kg in total) were mixed at a circumferential speed of 0.2 m/s.
The mixture was supplied to a drum-type granulator having an inner mold of 50 cm and a length of 1 m, which rotates at a speed of 100 cm, and primary granulation was performed at a residence time of 4 min while adding granulation water. Approximately half of the obtained aggregated wet granular material was air-dried and sieved using a 5-mesh and 16-mesh Tyler standard sieve to obtain granules with a product size of 5 to 16 mesh. Weight % was determined as product yield. The remaining wet granular material was moved at a circumferential speed of 0.2 m.
The granulator is fed to another drum-type granulator with an inner mold of 50 cm and a length of 1 m that rotates at a speed of 50 cm and a length of 1 m, and the granulation time is 3 to 4 while adding granulation water.
Secondary granulation was performed at min. A part of the obtained secondary granulated product was collected and dried in a rotary dryer with an inner diameter of 38 cm and a length of 250 cm at a rotation speed of 5 rpm, an inlet hot air temperature of 230°C, an outlet hot air temperature of 110°C, and an outlet product temperature of 80°C. Its moisture (wt%), product yield (wt%)
And the hardness (kg) was determined using a Kiya type hardness meter. The results are shown in Table 2. The moisture content of each raw material used was 11.7% by weight of rapeseed meal, 5.2% by weight of steamed bone meal, 10.2% by weight of processed fish waste fertilizer, and 2.5% by weight of ammonium phosphorus.

[0018]

[Table 2]

[Comparative Example] Powder raw materials of 36 parts by weight of steamed bone meal, 30 parts by weight of castor meal, 14 parts by weight of animal fertilizer, 4 parts by weight of ammonium sulfate, 4 parts by weight of urea, and 12 parts by weight of potassium sulfate (total 2 parts by weight) .3kg) in a pan-type granulator at a rotational speed of 23 rpm while adding granulation water without a granulation aid such as molasses.
Granulation operation for 3 to 6 minutes (first granulation only, number of tests 5 times)
As a result, the product size after natural drying (1 to 4 mm)
) had a maximum yield of 52% and an average of about 43.5%.

[0020]

Effects of the Invention According to the granulation method of the present invention, uniform core particles are produced in the first stage step without using special granulation aids such as molasses, and these are then used in the second stage of granulation. By using particles grown in the process, a granular fertilizer with an organic content of 60% or more and high hardness can be granulated efficiently at a yield of 80% or more and at low cost.

Claims (1)

[Claims] [Claim 1] A first step in which a raw material powder obtained by adding an inorganic raw material powder to an organic raw material powder is supplied to a granulator to form particle nuclei without using a granulation aid other than water or steam. Granular granules with a particle size of 1 to 4 mm are produced by the step step and the second step step in which the particle cores are continuously fed to another granulator, granulated, grown, and sized. A method for granulating granular fertilizer characterized by making.