JPH07144129A - Adsorbent consisting of carbide-containing calcined zeolite particles and its production - Google Patents

Abstract

PURPOSE:To produce an improved adsorbent which is adopted for an object to increase a manuring effect on a paddy field, etc., and to adsorb and remove a harmful substance incorporated in a plant waste water, etc., consisting of carbide-containing calcined zeolite particles especially having a versatility to an adsorption effect, favorable from the view of handling property as a material and to provide a production method therefor. CONSTITUTION:A wet powdery mixture obtained by injecting and mixing a binder consisting of an org. of an inorg. binder aq. soln. adjusted to 0.01-0.05% to a powdery mixture consisting of powder of a natural org. matter ground to <=2mm and a natural zeolite powder ground to <=250mum and having about 30% moisture content is granulated, then the obtained granules are calcined at a calcining temp. of an order of about 500-1000 deg.C to obtain the adsorbent consisting of the carbide-containing calcined zeolite particles.

Description

Detailed Description of the Invention

[0001]

OBJECT OF THE INVENTION The present invention relates to an adsorbent used for the purpose of enhancing the fertilizing effect in fields, adsorbing and removing harmful substances contained in factory wastewater, and the like.
It is intended to provide an adsorbent comprising improved carbide-containing calcined zeolite particles, which has a versatile adsorption effect and is advantageous in terms of handleability as a material, and a method for producing the same.

[0002]

2. Description of the Related Art Japan, which has continued to achieve unprecedented economic development in the world, is required by various countries to take positive measures against trade imbalances. There is a strong demand for liberalization of agricultural products, including mandarin oranges, cherries,
Some items such as beef have already been put into practice,
Although various ripples have been thrown into the country, a major issue that has yet to be resolved is how to deal with the liberalization of rice, which is our staple food. There is a strong support for the liberalization of rice because consumers will have an advantage in price selection.
Due to the special agricultural circumstances in Japan, which has promoted agricultural policies centered on rice cultivation, what kind of measures will be settled down is attracting attention both inside and outside Japan.

In response to such a severe situation that has never existed before, it is predicted that rice farms, who have started to maintain relatively stable agricultural management, will eventually move to a competitive market for rice as a trend. , Interest in improving efficiency and quality of cultivation due to expansion of scale, and measures to increase revenue,
While the government is also reviewing the food management system, it has begun to implement measures to motivate rice farmers, such as revising domestic rice distribution policy and introducing a voluntary rice distribution system. . The issue that requires the self-help efforts of each rice farmer in order to improve management efficiency is the establishment of cultivation techniques for high profitability and high quality.

[0004] Recently, due to the great interest in adverse effects on the human body or the natural environment, development of new pesticides, self-restraint of pesticide use, fertilizer application measures for the production of sturdy seedlings that do not rely on pesticides,
Many rice farmers are seriously studying cultivation techniques such as studying field management, and gradually implementing them. In particular, as a cultivation technique to meet the demands of high quality rice, it is important not only to cultivate new varieties but also to select fertilizers and measures for fertilizer application. ) Is being actively introduced, and various techniques for increasing fertilization efficiency are being studied.

As a conventional technique which has been adopted as a technique for improving fertilization efficiency, active carbon is actively sprayed and mixed in a field to prevent fertilizer from easily flowing out from the field and a microbial breeding environment. There is a method of ensuring the efficiency of decomposition of fertilizer and improving the absorption efficiency. The conventional measures to increase fertilizer application efficiency with activated carbon are to use the high adsorption performance of activated carbon, so it is effective in itself and many rice farmers introduce it, but activated carbon is relatively expensive. However, due to the difficulty that the economic burden is too large for large-scale adoption and the problem of handling and management that water easily flows out due to the increase in water drawn into the field or rainwater, activated carbon with these defects has recently been selected. Instead of
Due to its microscopic microscopic properties, natural zeolite (hydrous aluminosilicate), which has an extremely strong adsorption action for water, gas, bases, etc., is produced in Japan almost inexhaustibly and can be obtained at relatively low cost, in the field. It has begun to appear in the market and is attracting the attention of rice farmers because it is easy to get used to and there is little risk of outflow.

[0006] The adsorbents using the natural zeolite that have been introduced in this way are those obtained by simply crushing the natural zeolite into a proper particle size, firing them at a high temperature to obtain calcined zeolite particles, or natural zeolite powder. It may be obtained by adding water to the body, kneading and extruding into a cylindrical shape and then firing, or alternatively, by adding water to the natural zeolite powder body, kneading it into a spherical shape and then firing. However, all of them are natural zeolite alone, and their basic characteristics are the same.

By the way, when comparing the adsorption characteristics, for the natural zeolite alone, among the items such as domestic wastewater treatment capacity, heavy metal processing capacity, organic chlorine compound processing capacity, gas adsorption capacity, etc., for example, MEP (Sumithion). Except for the adsorption characteristics for some heavy metals, such as copper, zinc, and cadmium, most of the items have inferior or almost equivalent capabilities to the above-mentioned activated carbon. There is a weakness that zeolite alone cannot completely substitute for activated carbon. However, even if it is inferior in performance when compared to activated carbon, it still has the fact that it has exceptionally excellent adsorption properties in comparison with other substances, and therefore it can be supplemented by that value. Depending on the situation, it should be possible to use it as an adsorbent that sufficiently replaces the activated carbon due to the advantages of economy and handleability.

Based on the above recognition, the present invention has been earnestly developed and researched as a person who is deeply involved in natural zeolite, and as a result, in the process of granulating and calcining calcined zeolite particles from a natural zeolite powder body. The present invention has succeeded in realizing a charcoal-containing calcined zeolite particle in which a charcoal-containing material is contained so as to improve the adsorption property of the zeolite and a novel method for producing the same, and the constitution thereof will be described in detail below.

The gist of the constitution of the adsorbent of the present invention is to use a natural organic substance powder such as rice husk and sawdust scraped to 2 mm or less and 25
Into a powdery mixture consisting of a natural zeolite powder pulverized to 0 μm or less, 0.01-0.05% sodium carboxymethyl cellulose aqueous solution, other inorganic or organic binder, etc. were injected and mixed as a binder,
The adsorbent is composed of activated carbon-mixed calcined zeolite particles formed by granulating a moistened natural zeolite having a water content of about 30% and calcining at a calcining temperature of about 500 to 1000 ° C.

Further, the gist of the manufacturing method for manufacturing the above-mentioned adsorbent is as follows: 6: 4 parts by weight of a natural zeolite powder body crushed to 250 μm or less and a natural organic substance powder such as rice husk and sawdust scraped to 2 mm or less. To form a powdery mixture, and then add a sodium carboxymethylcellulose aqueous solution adjusted to 0.01 to 0.05% and other binder such as an inorganic or organic binder to obtain a water content of about 30%. %
After granulating from the natural zeolite wet body before and after,
Carbide that becomes an amorphous granular material with a particle size of 0.1 to 10 mm through a classifier after being baked for about 5 to 6 minutes in a rotary kiln heated to a temperature of about 800 to 1000 ° C. and then cooled. It is a method for producing an adsorbent composed of included zeolite particles.

Any natural organic matter powder can be used as long as it can be smoked and carbonized, such as rice husks, sawdust, and bark, and these are crushed to a size of 2 mm or less before use. The natural zeolite is, for example, a natural zeolite called "Itaya Zeolite" under the trade name and is produced from the border between Fukushima prefecture and Yamagata prefecture, and has an extremely high quality of about 70-80% purity. It is suitable if it is.

This natural zeolite is ground to a powder body of 250 μm or less, and the powdered natural organic substance ground to 2 mm or less is equal to or less than the same amount by weight percentage, for example, about 80% or so. An optimum ratio is selected that does not hinder the granulation process and that does not hinder the shape retention as granules in the firing process or the subsequent handling stages, and agitates in a homogeneous state. , Which is mixed into a powdery mixture, and the powdery mixture is
In a state where the natural organic matter powder is evenly distributed among the particles of the natural zeolite powder, when viewed from the side of the natural organic matter powder, fine powder is sprinkled on the surface and the natural zeolite powder is filled between them. It will be in a state of.

As the binder, various organic or inorganic binders such as sodium carboxymethyl cellulose (commonly known as CMC) commonly used as an organic binder can be adopted.
Desirably, it is adopted as a 0.03% aqueous solution, and an aqueous solution having a concentration below this range is likely to be disintegrated in the following steps of granulation and handling. Further, at a concentration higher than this range, there is a concern that the natural zeolite formed by firing may be damaged by CMC during the firing process and hinder the excellent function of the natural zeolite. It is desirable to keep the temperature in this range as long as possible.

In order to granulate the calcined zeolite particles containing carbide which is the object of the present invention using the CMC aqueous solution or the like having the above concentration as a binder, the water content of the mixed powder is about 30%. It is adjusted to the one of the above, and it becomes an ideal wet mixed powder for granulation, the state that the natural organic substance powder is evenly distributed among the natural zeolite powders, conversely from the natural organic substance powder side. Obviously, it must be ensured that fine natural zeolite powder is present around it and that the granular particles of about 0.1 to 10 mm are formed with the natural zeolite powder filled between them. . When realizing this water content, the water content (usually around 6 to 7%) of the natural zeolite powder itself is taken into consideration and C
It is necessary to determine the injection amount of the binder containing the MC aqueous solution and other aqueous solutions. In this granulation step, a known granulator such as a rotary container granulator or a centrifugal diffusion granulator, for example, a Reedige mixer (trade name; West Germany Reedige Co.) can be used, and the former is Continuous, the latter is granulated in a batch system.

The firing temperature in the firing kiln is about 500-
It should be set in a range of about 1000 ° C., and ideally, a firing temperature of around 700 ° C. is ideally selected. If the firing temperature range is too low, the smoke of the natural organic matter powder is smoked. There is a possibility that carbonization will not progress completely, and if it exceeds this range, the natural organic matter powder will burn out this time, producing calcined natural zeolite particles with no carbides in the calcined natural zeolite. Since there is a risk that it will occur, it is necessary to adjust the combustion within the optimum temperature range.

On the other hand, the natural zeolite calcined within this range is dehydrated and partially sintered to be modified from hydrous aluminosilicate into a kind of isomer condensed polycondensate porous ceramics, which is excellent as it is. The properties can be maintained, and the deterioration of the properties of the natural zeolite due to the CMC, which is a binder, can be set to a level that can be almost ignored, and firing will occur below this range. In addition to causing problems in shape retention and hardness as an irregularly shaped granular material, there is a greater risk that CMC will remain in the microscopic microscopic pores of natural zeolite, and the excellent nature of natural zeolite Performance is impaired, it is disadvantageous in obtaining a desirable adsorbent, and if the firing is far exceeding that range, the fine pore walls of natural zeolite will melt. Collapse pores, cause fear that is reduced, which also impossible to manufacture an ideal adsorbent utilizing the natural zeolite natural cast is an object of the present invention.

[0017]

Example 1 A specific example of the carbide-containing calcined zeolite particles of the present invention based on the above-mentioned constitution is as follows. That is, a natural zeolite powder body pulverized to 250 μm or less and a natural organic matter powder body pulverized to 2 mm or less such as rice husk and sawdust are homogeneously mixed at a ratio of 6: 4 by weight to form a powder mixture. 0.01 to 0.
Add a binder consisting of sodium carboxymethyl cellulose solution adjusted to 05% to make a wet powdery mixture with a water content of about 30%, and after granulation, continue to a rotary kiln heated to a temperature of about 900 ° C. The adsorbent is composed of calcined zeolite particles containing carbide, which is charged and calcined, cooled with a cooler, and then sieved into granules having a particle size of about 0.1 to 10 mm.

[0018]

[Embodiment 2] Next, a concrete embodiment of a method for producing an adsorbent made of calcined zeolite particles containing a carbide will be described. First,
The natural zeolite powder pulverized to 250 μm or less and the chaff pulverized to 2 mm or less are hung on a quantitative feeder and weighed so that the mixing ratio of each is about 6: 4 in parts by weight, and rolling container type rolling The mixture is put into a granulating machine, for example, a Loedige mixer granulating machine (trade name), sufficiently mixed and stirred to form a homogeneous powdery mixture, and the concentration is about 0.03.
% CMC aqueous solution was injected to obtain a wet powdery mixture having a water content of about 30%, and the granulator was operated to give a density of 0.
A granular material having a size of about 1 to 10 mm is formed. As described above, the injection amount of the CMC aqueous solution must be determined in consideration of the water content of the natural zeolite powder itself (usually around 6 to 7%).

When a predetermined amount of granular material is stocked, it is sent to a rotary kiln by a belt conveyor, and about 8
Combustion temperature around 00-1000 ° C (500 at product temperature)
Approximately about 800 ° C.) for about 5 to 15 minutes, and then naturally cooling or cooling to about 60 to 100 ° C., preferably about 60 ° C. which is as low as possible.
The calcined granules taken out after cooling become calcined natural zeolite containing carbides inside, and they are made to have a particle size of about 0.1 to 10 mm with a sieving device, and weighed in predetermined amounts. Will be packed in bags.

[0020]

[Advantages] The characteristics of the adsorbent composed of the calcined zeolite particles containing carbide of the present invention produced as described above are compared with those of activated carbon, and the results of experiments are shown as follows. First, the results of the domestic wastewater treatment test are as shown in Table 1. The adsorbent of the present invention surpasses that of activated carbon in the removal rate of MEP, which is a typical pesticide, and other biochemical oxygen demands and chemicals. The oxygen demand, normal hexane extract, nitrogen and phosphorus removal rates are slightly inferior to or equivalent to those of activated carbon, and as far as these items are concerned, it can be a sufficient substitute for activated carbon. Understand.

[0021]

[Table 1]

The test water used in the above-mentioned test was a sample obtained by adding Sumithion to about 10 ppm to the water collected in the domestic wastewater drainage channel in Semine-cho, Kurihara-gun, Miyagi Prefecture. The sample preparation method is as follows: 4.5 kg of the test material is placed in a container (0.1 cubic meter), 4.5 liters of the test water (raw water) is placed therein, and the test material is left in contact for 10 hours. However, the test water (treated water) was then collected.

Next, Table 2 shows the test results of the organic chlorine compound treatment test. The test water used in the above test was tap water from Sendai City, and a sample prepared by adjusting each substance to about 5 mg / l was used as raw water. The test was conducted for each single component.
In addition, the method for preparing the sample liquid is to put 4.5 kg of the test material in a container (0.1 cubic m), put 4.5 liters of the test water (raw water) therein, and contact with the test material for 10 hours, This is due to a method in which the test water (treated water) is recovered after being left standing. From the results of these test items, the adsorbent of the present invention shows a high removal performance value which is almost equal to the removal rate of activated carbon in all items.

[0024]

[Table 2]

Table 3 shows the results of the heavy metal treatment test. From this data, the adsorbent of the present invention surpasses that of activated carbon in the removal rate of mercury, and is almost comparable to that of activated carbon in the removal rates of other heavy metals. The test water used in the above test was tap water from Sendai City, and the sample was adjusted to about 100 mg / l of each substance using the specified reagents as raw water. The test was conducted for each single component. is there. The sample solution is prepared by putting 100 ml of test water in an Erlenmeyer flask (300 ml), adding 1 g of the test material therein, leaving it at room temperature for 24 hours, and filtering it to obtain treated water. is there.

[0026]

[Table 3]

As described above, the adsorbent composed of the calcined zeolite particles containing carbide according to the present invention not only retains the characteristics originally possessed by natural zeolite, or further strengthens and maintains them, but also integrates the carbide therein. Since this carbide functions as activated carbon and has a function of complementing the weak part in the characteristics of natural zeolite, it is an adsorbent consisting of only natural zeolite or a calcined zeolite alone obtained by firing it. Compared to, the performance is greatly improved, and it is almost the same as that of the activated carbon alone.

Also in the production method, the natural organic material powder is uniformly dispersed between the natural zeolite powder particles in the powder mixture stage, and the water content is adjusted to a predetermined range to form a wet granulation. As a result of the natural zeolite powder being adhered and filled around the natural organic powder in the step, the natural organic powder is naturally included in the natural zeolite powder, and it is fired at a predetermined temperature. According to this, carbonization of the natural organic matter powder is simultaneously performed in the natural zeolite firing step, and mass production is possible.

Therefore, as far as the adsorption characteristics are such that the performance thereof is sufficiently comparable to that of activated carbon, it is economically far less expensive than the adsorbent made of activated carbon alone. The adsorbent can be used as an extremely practical adsorbent, and as a field adsorbent that must be used in a large amount, of course, a water pollution control material,
It is possible to exert an extremely excellent feature that it can greatly contribute to use as a groundwater pollution prevention material, an environmental purification material such as deodorant, or an adsorbent material for raw garbage treatment material and the like. These features will be further promoted by the concrete configuration shown in the embodiment.

As described above, the adsorbent comprising the carbide-containing zeolite particles and the method for producing the same according to the present invention are intended to further enhance the original properties of natural zeolite and to stably exhibit them. Since it can be easily produced, in terms of its handleability, economical efficiency, safety, etc., it is not only an adsorbent consisting of natural zeolite or a calcined natural zeolite obtained by calcining it, but it is also composed of activated carbon alone. It can exhibit excellent characteristics that surpass those of other materials, and is expected to be highly evaluated as an adsorbent for various applications and a method for producing the same. │

[Table 2]

[Table 3]

Claims (3)

[Claims] 1. A powdery mixture comprising a natural organic matter powder such as rice husk and sawdust scraped to 2 mm or less and a natural zeolite powder ground to 250 μm or less, 0.01 to 0.0
About 500-1000 ° C after granulation from a wet powdery mixture having a water content of about 30%, which is prepared by injecting and mixing a binder made of an organic or inorganic binder aqueous solution such as sodium carboxymethylcellulose solution adjusted to 5%. An adsorbent material comprising carbide-containing calcined zeolite particles calcined at the calcining temperature of. 2. A powdery mixture in which a natural zeolite powder body crushed to 250 μm or less and a natural organic matter powder body crushed to 2 mm or less such as rice husks and sawdust is uniformly mixed in a ratio of 6: 4 by weight. After forming the body, a binder made of an organic or inorganic binder aqueous solution such as sodium carboxymethyl cellulose aqueous solution adjusted to 0.01 to 0.05% was added to obtain a wet powdery mixture having a water content of about 30%. After granulation, the powder is continuously charged into a rotary kiln heated to a temperature of about 800 to 1000 ° C., fired, cooled, and then sieved into granules having a grain size of 0.1 to 10 mm. An adsorbent consisting of calcined zeolite particles. 3. A powdery mixture in which a natural zeolite powder body pulverized to 250 μm or less and a natural organic matter powder body pulverized to 2 mm or less such as rice husks and sawdust are uniformly mixed in a ratio of 6: 4 by weight. After forming the body, a binder made of an organic or inorganic binder aqueous solution such as sodium carboxymethyl cellulose aqueous solution adjusted to 0.01 to 0.05% was added to obtain a wet powdery mixture having a water content of about 30%. After granulating, granules are fired in a rotary kiln heated to a temperature of about 800 to 1000 ° C. for about 5 to 15 minutes and then cooled, and then granulated through a classifier to have a particle size of about 0.1 to 10 mm. 1. A method for producing an adsorbent comprising carbide-containing calcined zeolite particles, which is produced by sieving.