JPH01199524A - Production of gravel for cultivating plant - Google Patents

Abstract

PURPOSE:To provide gravel having a high porosity, fine pores and an excellent water-retaining property, by kneading ground mineral powder with a binder decomposing or disappearing at high temperatures, granulating the kneaded product with a rolling granulator, etc., and calcining the produced granules in a stationary state. CONSTITUTION:A mineral powder ground into sizes of <=100 meshes is kneaded with a binder decomposing or disappearing at high temperatures and the produced mixture is granulated with a rolling granulator or fluidized bed granulator in a state wherein any compression power is not applied to the mixture. The granulated products are calcined at 900-1,300 deg.C to provide calcined products having fine open pores over the whole region thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing a vegetable cultivation pot with excellent water retention properties.

[Conventional technology]

BACKGROUND ART Reki, which is made by granulating mineral components such as silica stone and clay and hardening them by firing, has recently come to be used as soil for plant cultivation instead of natural soil. One such product is fired foam reki. This is made by mixing clay and water, and
Manufactured by foaming at 1200°C. This fired foam reki has better air permeability and water retention than natural reki.

[Problem to be solved by the invention]

However, conventional fired foamed clay has a large particle size, so its water retention is inferior to that of natural soil. Therefore, when using this fired foamed clay as soil for potted plants, etc., it is necessary to place the pot in an area surrounded by clouds that is illuminated by weak light, such as indoors. In addition, since it is too light, it does not hold plants sufficiently, and tall plants may fall over.

Furthermore, conventional reki is fired at a high temperature that almost melts the mineral components. Therefore, internal voids are formed only in the foamed areas, and the other areas have a dense structure. Due to this structure, Reki's water retention is not sufficient. for example,
When growing plants in an environment exposed to direct sunlight, constant watering is required.

Therefore, an object of the present invention is to obtain a liquid resin having high porosity, fine voids, and excellent water retention by forming internal voids through decomposition or disappearance of the binder.

[Means to solve the problem]

In order to achieve the objective, the method for manufacturing rectangles of the present invention has the following features:
Either the mineral powder is crushed to 100 mesh or less, or the mineral powder is kneaded with a binder that decomposes or disappears at high temperatures, and the resulting mixture is granulated using a rolling granulator or a fluidized bed granulator, or the mineral powder is mixed with the Granulate with a rolling granulator or fluidized bed granulator while spraying the remaining binder onto a mixture in which a portion of the binder is kneaded, or while spraying all of the binder onto the mineral powder, and then granulate. Let the particles stand still -
It is characterized by firing at a temperature of 900 to 1300°C.

The mineral component is clay whose main component is silicic acid.

Silica stone, waxite, china stone, bentonite, etc. are used. When these mineral components are mixed in an appropriate proportion, a mulch with a pH suitable for the type of plant to be cultivated can be obtained. Further, as the binder, a material that easily decomposes or disappears at a temperature of 1300° C. or lower is used. These materials include polyvinyl alcohol (PVA), sodium carboxymethylcellulose (CMC), polyvinylpyrrolidone (PVP), and hydroxyethylcellulose (HEC).

Examples include likunin waste molasses, soybean meal, corn starch, and starch. In some cases, two or more of these may be used in combination.

[Effect]

The mineral component used in the present invention is pulverized to 100 mesh or less and kneaded with a binder, or the binder is sprayed onto it. Therefore, the binder is evenly distributed throughout the mixture, and when the mineral powder is fired in the subsequent process, very fine voids are formed throughout the slag.

Also, when granulating a mixture of mineral powder and binder,
Alternatively, when granulating mineral powder or a mixture of mineral powder and binder while spraying a binder, a rolling granulator or a fluidized bed granulator is used.

For example, in a rolling granulator, the mixture is granulated as it rolls over a pan. Therefore, the mixture is not subjected to compressive force during granulation. Further, in a fluidized bed granulator, granulation can be similarly performed without being subjected to compressive force.

The granules are then fired in a stationary state. For example, the granules are arranged in a tray, and the tray is placed in a kiln to fire the granules. Alternatively, a type in which the tray is moved within the firing kiln, such as a shuttle kiln, tunnel kiln, roller hearth kiln, etc., may be used. The key is to perform the firing in such a way that no unexpected force is applied to the granular material during the firing. Therefore, the fired granules are not consolidated and are not agglomerated during firing.

Firing of the granules is carried out at a temperature range of 900 to 1300°C. When this firing temperature is maintained, a fired body having sufficient strength and a non-densified structure can be obtained. That is, when the firing temperature is lower than 900°C, the strength of the obtained fired body is not sufficient and it easily collapses. However, when the firing temperature exceeds 1300°C, part of the mineral powder becomes molten and the structure becomes dense.

During this firing process, the binder mixed with the mineral powder is decomposed or lost. As a result, fine open voids are uniformly formed over the entire area of the fired body, resulting in a fired body with a porous structure. This porous structure (J, (☆) is different from that formed by foaming of fat, etc., and is extremely fine. Therefore, it has excellent water retention ability, and the number of times of water supply is 1/49 less than that of conventional reki. It becomes possible to grow plants.

In addition, since it has ylene exchange ability, when fertilizer components are added, it can ion exchange organic acids such as root acids excreted from the roots of plants, and prevent root rot caused by root aging and decomposition. can. Furthermore, since fertilizer components can be included, plant growth is also promoted. Furthermore, it is heavier than conventional fired foam receptacles, so it can be used for outdoor potted plants, etc.

〔Example〕

The silica stone was ground to an average of 200 mtsunyu, chopped into 4 parts by weight of silica stone, and mixed with clay at a ratio of 1 part by weight of clay.

This mineral powder formulation contains carboxymethylcellulose (contains carboxymethyl cellulose)
1% of IJum was added and kneaded. The obtained mixture was fed into a pan of a transfer granulator, and the pan was rotated at a rotational speed of 3 Or, p, m while spraying water to obtain an average particle size of 8 mm.
The granules were molded. Next, this granular material was charged into a Nyatle kiln and maintained at a maximum heating temperature of 1200° C. for 30 minutes.

This heating left many pores between the powder particles, and the carboxymethylcellulose sodium added as a binder was completely decomposed, leaving traces of it in the form of countless fine voids in the fired body.

The obtained reki had an average dry weight per I Fi of 0.
The weight was 365 g, the density was 1.25 g/cnt, and the crushing strength was 35 kg/cnl, and it was found to have sufficient durability under normal usage conditions. Also,
This soil is neutral and suitable for cultivating both acidic and alkaline plants depending on the type of fertilizer components added.

In addition, to examine the water retention capacity of Reki, tests were conducted under the following conditions. First, the entire reki was immersed in a water bath for 4 hours to fully absorb water. Next, the water-absorbed reki is heated to a temperature of 2
The pellets were placed in air at 0° C. and 60% relative humidity, and the weight of each pellet was measured after a predetermined period of time had elapsed. Then, the value obtained by subtracting the dry weight from this measured weight was determined to be the amount of water absorbed by the reki at that point.

Table 1 shows the results of this test.

In addition, Table 1 shows 50% kaolin clay and Monmo IJ.
50% D-night clay was mixed with water and granulated using an extrusion granulator, and then spheroidized using a granulator.
Put it in a rotary kiln heated to 0℃ and bake it.
Foamed Reki is listed as a comparative example. The dry weight of each grain (average particle size: 8 mm) of this fired foam reki is:
It was about 0.294 g.

Table 1 Changes in water absorption of Reki (Unit: mg) As is clear from Table 1, the Reki of the comparative example lost more than half of its water absorption 16 hours after being immersed in the water bath. There is. Therefore, when using this water tank for plant cultivation, it was necessary to supply water every 12 hours. In addition, the water absorber of this example retained a sufficient amount of water even after 48 hours had passed, and the number of times water was supplied could not be reduced accordingly.

〔Effect of the invention〕

As explained above, in the present invention, the mineral powder is processed without applying compressive force to increase the pore volume during granulation and firing, and moreover, the decomposition or disappearance of the binder causes fine particles to form inside the grain. This creates countless voids. Therefore, the resulting water retention capacity is excellent, and it becomes possible to maintain the soil for plant cultivation in a moist atmosphere for a long period of time with one water supply. It also has high crushing strength,
Can be used repeatedly.

Patent applicant Mizu 1) Yutaka Drink

Claims (1)

[Claims] Mineral powder crushed to 1,100 mesh or less and a binder that decomposes or disappears at high temperatures are kneaded, and the resulting mixture is granulated using a rotary granulator or a fluidized bed granulator, A method for producing a plant cultivation pot, which comprises: then baking the granulated particles at a temperature of 900 to 1,300°C while keeping the granulated particles stationary. 2. Rolling while spraying the remaining binder to a mixture obtained by kneading the mineral powder described in claim 1 with a part of the binder described in the same claim, or while spraying all the binder to the mineral powder. Granulate with a granulator or fluidized bed granulator,
Next, the granulated particles are kept stationary and 900-1
A method for producing a plant cultivation pot characterized by firing at a temperature of 300°C. 3. A plant characterized by using one or more of clay containing silicic acid as a main component, silica stone, waxite, pottery stone, and bentonite as the mineral powder according to claim 1 or 2. A method of manufacturing reki for cultivation. 4. As the binder described in claim 1 or 2, one or more of polyvinyl alcohol, sodium carboxymethylcellulose, polyvinylpyrrolidone, hydroxyethylcellulose, lignin waste molasses, soybean meal, corn starch, and starch are used. A method for producing a vegetable cultivation pot characterized by: