JP2003002636A - Binder-less zeolite bead molding, manufacturing method for the same, and adsorbing and removing method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a binder-less zeolite bead molding having both a high strength property and an excellent adsorbing performance, a manufacturing method for easily obtaining the binder-less zeolite bead molding, and a method for adsorbing and removing a specific component in a gas or water by using the molding. SOLUTION: The binder-less zeolite bead molding has >=95% zeolite content. A part or all of exchangeable sodium ions in the molding are exchanged with univalent to tervalent cations or the mixture of these ions, and the particles having >=1.7 mm diameter in the whole particles of the molding have >=6 kgf mean pressure resistance. In the manufacturing method, a mixture of raw materials is molded, baked, made binder-less, ion-exchange, and activated. The method for adsorbing and removing adsorbed substances is conducted by using this binder-less zeolite bead molding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a so-called high-strength binderless zeolite bead molded body having a low binder content and excellent physical strength of the molded body, and a method for producing the same. Further, the present invention relates to a method of using this to adsorb and remove the substance to be adsorbed in the gas or the liquid. Specifically, it is widely used industrially as a dehydrating dehydrating agent or for adsorption separation, and is useful in the fields of, for example, fluorocarbon refrigerants, removal of water in organic solvents, and adsorption separation of carbon dioxide, which is an environmental problem of global warming. Strength binderless zeolite bead molded body and method for producing the same,
Further, the present invention relates to a method of using this to adsorb and remove the substance to be adsorbed in the gas or the liquid.

[0002]

2. Description of the Related Art Usually, a zeolite compact is formed by adding zeolite powder, a clay-based binder, a thickener or a dispersant, etc., and granulating the mixture into beads, pellets or the like according to the purpose.

In order to exhibit excellent adsorption performance in an adsorbent produced by using zeolite and a non-adsorbing component such as a clay-based binder, the binder component is reduced and the content of zeolite, which is an effective adsorbing component, is increased. It is necessary.

On the other hand, the required physical properties and characteristics differ depending on the use of the adsorbent. For example, in the case of a desiccant for the purpose of removing water, it is used under severe conditions such as vibration and heat regeneration. Therefore, there has been a demand for a molded product having a bead-like shape and high physical strength, which is less likely to cause peeling or powdering of the molded product.

Conventionally, in order to improve the strength and physical properties of molded products, it has been the actual practice to mold with a large amount of clay-based binder, but as the amount of binder increases, the zeolite content decreases in proportion. In addition, the adsorbent does not have a satisfactory adsorption performance, and the binder is non-uniformly dispersed, resulting in large variations in the strength physical properties and the adsorption ability.

As a method for increasing the content of zeolite, JP-A-57-122932 discloses that a columnar molded body composed of sodium A-type zeolite powder and a kaolin-based clay binder is fired and a clay component is added using an aqueous sodium hydroxide solution. A binderless method for making a zeolite is disclosed.

Japanese Patent No. 2756567 discloses that a mixture of zeolite, kaolin clay, and carboxymethyl cellulose having a degree of polymerization of 800 or more is extruded and molded.
It is disclosed that a columnar molded article having high strength and physical properties can be obtained by firing.

In Japanese Patent No. 3066427, a mixture of zeolite, kaolin clay, sodium hydroxide and carboxymethyl cellulose is extruded, calcined,
It is disclosed that a columnar molded article having higher strength and physical properties can be obtained by making the binderless using an aqueous solution of sodium hydroxide.

[0009] Japanese Patent No. 2782744 discloses that when a columnar shaped article having an increased amount of kaolin clay is made binderless, the strength of the obtained article is improved, but the zeolite content is low. .

In Japanese Unexamined Patent Publication (Kokai) No. 10-87322, a mixture of zeolite, kaolin clay and carboxymethyl cellulose is extruded into a columnar shape, and then rolling and sizing is performed to transform the shaped body into a bead shape and then fired. Although a method is disclosed, the strength of the obtained molded body is insufficient as the strength of the molded body when used under severe conditions such as desiccant application.

Further, when it is used as an adsorbent or a desiccant, part or all of the exchangeable cation moieties of the zeolite are ion-exchanged with cations belonging to alkali metals, alkaline earth metals, transition metals, rare earth elements and the like. Used.

As a method of ion exchange, a known method or a method of contacting zeolite with an aqueous solution containing these cations and performing ion exchange is used. For example, JP-A-6-18
For 3726, a mixture of sodium A-type zeolite, kaolin clay, sodium hydroxide, and carboxymethyl cellulose is extruded into a columnar shape, fired, and made binderless with an aqueous sodium hydroxide solution, and then an aqueous calcium chloride solution is used. Ion exchange, calcium A
It is disclosed that excellent adsorption characteristics and mechanical characteristics can be obtained by changing the type of zeolite into a zeolite and by changing the exchange rate of calcium ions from 40% to less than 70%.
The pressure resistance of the molded product actually obtained is 4 kgf or less, and when used for a desiccant, a molded product having more excellent strength physical properties has been required.

[0013]

DISCLOSURE OF THE INVENTION The present invention overcomes the conventional problems associated with such a molded zeolite bead,
Above all, there is provided a binderless zeolite bead molded body having a combination of strong physical properties and excellent adsorption performance required for use in a dry dehydrating agent, a method for producing the same, and an adsorption removal method using the same.

[0014]

Means for Solving the Invention As a result of intensive studies conducted by the present inventors to solve the above problems, zeolite 1
20 to 35 parts by weight of kaolin clay and 4 to 4 parts by weight of an aqueous solution of an alkaline dispersant which is alkaline and highly water-soluble.
After firing a zeolite bead molded body formed by rolling granulation from a mixture of 10 parts by weight or / and 0.5 to 5 parts by weight of a cellulose derivative, it is brought into contact with an aqueous sodium hydroxide solution to form a binderless form, ion exchange and activity. Depending on the method of conversion, some or all of the exchangeable sodium ions are exchanged with monovalent to trivalent cations or mixtures thereof with a zeolite content of 95% or more, preferably 98% or more, and The inventors have found that a binderless zeolite compact having an average value of compressive strength of particles having a particle diameter of 1.7 mm or more among particles of 6 kgf or more can be obtained, and completed the present invention.

The present invention will be described in detail below by taking A-type zeolite as an example.

The method for producing a binderless zeolite molded article of the present invention comprises 20 to 35 parts by weight of kaolin clay and 4 to 10 parts by weight of an aqueous dispersion of an inorganic dispersant which is alkaline and highly water-soluble with respect to 100 parts by weight of zeolite. Part or / and 0.
It is composed of a step of contacting a zeolite bead molded body molded by tumbling granulation from a mixture with 5 to 5 parts by weight of a cellulose derivative with a sodium hydroxide aqueous solution to make it binderless, ion exchanged and activated. , Will be described in order.

The type of zeolite of the present invention is not particularly limited, but as described above, A-type zeolite or X-type zeolite is preferably used in view of the molecular diameter of the substance to be dried. The method for producing the A-type or X-type zeolite is a known method, that is, it is synthesized using sodium aluminate, sodium silicate, and sodium hydroxide as raw materials.

Kaolin clay is used as the clay binder of the present invention. The kaolin-based clay is a clay belonging to kaolin minerals, and examples thereof include kaolinite, halloysite, kibushi clay and frog eye clay.

These clay binders are present between the zeolite particles in the molded article, and in particular, the density of the molded article is high in order to improve the strength of the molded article, that is, the ratio of voids present in the zeolite bead molded article, that is, In order to reduce the porosity, those having a primary particle diameter of 1 μm or less are preferable, and examples thereof include Georgia kaolin clay. These may be used alone or in combination of two or more.

The mixing ratio of the kaolin-based clay is in the range of 20 to 35 parts by weight based on 100 parts by weight of the zeolite powder on an anhydrous basis in order to obtain a high physical strength of the molded product and to obtain a high binder content without binder. Is preferred. When it exceeds 35 parts by weight, it takes a long time for the metakaolin component to be converted into zeolite crystals in the binderless process, and the central part of the molded body is not completely converted into zeolite crystals, so that a high zeolite content cannot be obtained. Also, 20
When the amount is less than the weight part, the physical strength may not be satisfied and it may be difficult to endure the purpose of use as a dry dehydrating agent.

The present invention is characterized in that an aqueous solution is mixed with an alkaline and highly water-soluble inorganic dispersant or / and a cellulose derivative when a zeolite bead molded body is obtained.

As the inorganic dispersant of the present invention, a condensed phosphate or an aluminate whose aqueous solution is alkaline and has high water solubility is preferable. Examples of the condensed phosphate include sodium pyrophosphate, sodium tripolyphosphate, potassium pyrophosphate, sodium hexametaphosphate, potassium hexametaphosphate, and the like, among which sodium pyrophosphate, sodium tripolyphosphate, and potassium pyrophosphate are preferable. There is no problem even if these are used alone or as a mixture of two or more kinds.

Examples of aluminates include sodium aluminate and potassium aluminate, with sodium aluminate being preferred. You may use these individually or in mixture of 2 types. Further, there is no problem even if the condensed phosphate and the aluminate are used in combination.

The mixing number of the inorganic dispersant of the present invention is preferably 4 to 10 parts by weight. Therefore, when the condensed phosphate is used, 2 to 5 parts by weight based on phosphorus pentoxide,
Also, when using an aluminate, 2 to 5 parts by weight based on aluminum oxide is dissolved in water and added. The amount of water added is not particularly limited, but is preferably in the range of 40 to 60 parts by weight. If the amount of the inorganic dispersant exceeds 10 parts by weight, the water cannot be dissolved in the water used for mixing and kneading, and the mixture is mixed in a slurry state, so that the mixed and kneaded product cannot be uniformly dispersed and uniform molded product strength can be obtained. Absent. Therefore, condensed phosphates and aluminates having high solubility in water are preferable. If the amount of condensed phosphate or aluminate is 4 parts by weight or less, the dispersion effect is insufficient and the physical strength is not satisfied.

Among the condensed phosphates, those whose aqueous solution is acidic cause a crystal collapse of zeolite in the case of a zeolite having low acid resistance such as A-type zeolite, and therefore those which are alkaline as the aqueous solution are preferable. .

The cellulose derivative of the present invention belongs to a thickening polysaccharide. Carboxymethyl cellulose (hereinafter referred to as CMC), hydroxyethyl cellulose, hydroxypropylmethyl cellulose, hydroxypropyl cellulose, which belong to the cellulose derivatives,
Among them, ethyl cellulose is preferable, and CMC is preferable among them.
In addition, guar gum, hydroxypropyl guar gum, which belongs to the guar gum derivative, and xanthan gum, welan gum, and gellan gum, which belong to the biogum, can be used. Examples of the effect of the thickening polysaccharide include improving the strength of the molded product by improving the particle adhesion force during granulation by utilizing the thickening effect, and improving the molding operability and yield.

The number of parts of the cellulose derivative mixed is 0.5.
The range of 5 parts by weight is preferred. When the number of mixed parts is 5 parts by weight or more, the thickening effect is too strong, so that the formed bead-shaped molded articles adhere to each other and cannot be uniformly molded. On the other hand, if it is less than 0.5 part by weight, the thickening effect is insufficient and the physical strength is not satisfied.

These thickening polysaccharides may be used alone or in combination of two or more. Further, there is no problem even if the inorganic dispersant of the present invention is used in combination with at least one of condensed phosphate and aluminate. Further, in order to obtain a high zeolite content, it is preferable that these thickening polysaccharides are not burned or decomposed in the firing step after molding and do not remain in the molded body.

The zeolite powder, the kaolin-based clay, the inorganic dispersant whose aqueous solution is alkaline and / or the water-soluble cellulose derivative and / or the cellulose derivative described above are mixed and kneaded by adding necessary water. The mixing method is not particularly limited, and it can be carried out using a ribbon blender, a kneader, a Nauter mixer, a mix muller, etc., but the bulk density of the obtained mixture is 0.8 to 1.0 kg / liter. preferable. When the bulk density of the mixture is less than 0.8 kg / liter, the compaction effect is insufficient and a large number of pores are present between the particles of the mixture, so that a high molded body strength cannot be obtained.

The present invention is characterized in that it is molded into beads by rolling granulation in order to obtain high strength of the molded body.

The rolling granulation includes plate type, pan type, drum type, and blade stirring type rolling granulation methods, and among them, the blade stirring type rolling granulation method is preferable. This is because a strong shearing force is applied by stirring with a blade as compared with ordinary rolling granulation, and a compact having a small void can be formed.

Further, when physical strength, particularly abrasion strength is required, it is desirable to use a bead molding having a high sphericity, and the molded beads can be rotated by a known method, for example, using a Marumerizer molding machine. It is a generally practiced method to smooth the surface of a molded product by sizing under the condition of several times. Further, the particle size distribution of the zeolite bead molded body obtained in the present invention is as wide as 0.1 to 20 mm, but it is necessary to select the size of the beads to be molded and sized according to the use, such as a sieve. All you have to do is classify by size.

The molded body thus molded is dried,
The kaolin-based clay binder that has been calcined and added is converted into amorphous metakaolin and sintered. A known method can be used as the drying and firing method, for example, using a hot air dryer, an electric muffle furnace, a tubular furnace, a rotary furnace, or the like.
The firing temperature may be in the range of 400 to 700 ° C.

Then, the obtained calcined product is brought into contact with an aqueous solution of sodium hydroxide to make it binderless. The binderless method may be performed using a known method at a temperature of 50 to 100 ° C. using a 3 to 10 wt% sodium hydroxide aqueous solution.

The zeolite content of the binderless zeolite bead molded product of the present invention can be determined by firing and activating the binderless molded product.

Next, the shaped body having a high zeolite content is subjected to ion exchange by bringing a part or all of the exchangeable sodium ions into contact with an aqueous solution containing monovalent to trivalent cations or a mixture thereof.

The monovalent to trivalent cations include alkali metals, alkaline earth metals, transition metals and rare earth elements. Among them, alkali gold metal and alkaline earth metal are preferable for obtaining high water adsorption capacity. . Examples of alkali metals include sodium, potassium, lithium, cesium, rubidium, and francium. Among them, sodium,
Potassium and lithium are preferred. Examples of the alkaline earth metal include calcium, magnesium, barium, strontium, beryllium, and radium. Of these, calcium and magnesium are preferable. As a transition metal,
Examples include iron, copper, titanium, silver, zirconium, platinum, gold, tungsten, chromium, manganese, nickel, cobalt, gallium, and germanium, and rare earth elements include scandium, yttrium, lanthanum, cerium, neodymium, promethium, and samarium. Is mentioned.

The ion exchange method is a known method, using an aqueous solution of chloride, hydroxide, nitrate, carbonate or acetate of these metals, and using an aqueous solution prepared to a concentration of 0.1 to 5N.
It may be performed at a temperature of 10 ° C to 90 ° C. When the exchangeable sodium ions are made into a mixture of cations selected from alkali metals, alkaline earth metals, transition metals, and rare earth elements, ion exchange may be performed using a mixed aqueous solution containing the cations.

The cation exchange rate can be selected according to the purpose because the adsorption characteristics vary widely depending on the type of zeolite, the type of exchange cation or the exchange rate.

For example, when sodium A type zeolite is exchanged with potassium ions, the water adsorption capacity decreases,
Since the zeolite pore size changes from 4Å to 3Å, potassium A-type zeolite having a zeolite pore size of 3Å is effective for adsorbing and removing only water contained in a gas having a small molecular size such as nitrogen. According to Japanese Patent Laid-Open No. 6-48728, the exchange rate of 3Å is disclosed to be 16% or more.

The ion-exchanged molded product is washed with water, dried, and activated by firing. A known method can be used as the calcination activation method. For example, a hot-air dryer, an electric muffle furnace, a tubular furnace, a rotary furnace, or the like can be used, and the calcination activation temperature can be 300 to 700 ° C. Good.

The thus obtained binderless zeolite bead molded product is characterized in that the shape thereof is a bead shape. Further, the size of the molded body is not limited, but when it is used as an adsorbent, in order to obtain high dynamic adsorption performance, the range of the particle size of 0.5 to 5 mm is 90%.
It is preferable to include the above.

When used as a desiccant, in order to obtain a satisfactory strength of the molded body of 6 kgf or more, 1.7 to 2.
It is preferable that the range of 4 mm includes 90% or more. Further, in order to improve the filling property of the desiccant in the filling container within this particle size range, the particle size range of 1.7 to 2.0 is uniform.
Those having a particle size of 90% or more in mm are preferable.

The binderless zeolite bead molded product obtained in the present invention has a zeolite content of 95% or more, preferably 98% or more, and some or all of the exchangeable sodium ions are monovalent to trivalent cations. Or, it is exchanged with a mixture of these, and the particle size of all particles is 1.7 m.
The average value of the compressive strength of particles of m or more is 6 kgf or more.

Further, the binderless zeolite bead molded product of the present invention is widely used for dry dehydration or adsorption separation. For example, it can be used as a dehydrating agent for refrigerant CFCs used in various refrigeration and air-conditioning equipment for car air conditioners, etc., and also as a dehydrating agent for air brakes for large vehicles, removal of water in organic solvents or air,
It is also useful in the field of adsorption / separation agents such as the adsorption of carbon dioxide, which is an environmental problem of global warming.

Further, by subjecting the binderless zeolite bead molding of the present invention to silver ion exchange using a silver nitrate aqueous solution or the like, it is possible to simultaneously remove water contained in natural gas or ethylene gas and a small amount of mercury.

[0047]

EXAMPLES The present invention will now be described in more detail with reference to examples, but the present invention is not limited thereto. In addition, each evaluation was implemented by the method shown below.

(1) Bulk Density In accordance with the method using an apparent density measuring device of JIS-K-3362, the mixture after mixing and kneading is received in a polyethylene cup (W1) having a volume of Vml, and a straight line is formed at a heap. After scraping off with a spatula, the weight (W2) of the cup containing the mixture was read up to the unit of 1 g, and the bulk density was calculated by the following formula.

Bulk density (kg / liter) = (W2-W1) / V (2) Moisture equilibrium adsorption amount After desiccating and firing the binderless zeolite bead molding, the desiccator at a temperature of 25 ° C. and a relative humidity of 80% It was left to stand for 16 hours or more to be completely hydrated. Then
The mixture was fired at 900 ° C. for 1 hour in a muffle furnace, and the moisture equilibrium adsorption amount adsorbed on the molded body was measured.

(3) Pressure-resistant strength After ion-exchange, washing and drying, the calcined and activated binderless zeolite bead molded body is cooled to 1.7 to
Quickly sieving with a 2.4 mm two-stage sieve so as not to adsorb water, of which 1.7-2.0 mm 25
The individual pieces were measured one by one with a hardness meter (manufactured by Fujiwara Seisakusho, model: KHT-20). The measurement is based on a method of applying a load to the molded body at a constant speed with an indenter having a diameter of 5 mm, and the weight when the molded body is crushed is defined as the compressive strength (kgf),
The average value of the obtained values was used as the pressure resistance strength of each Example and Comparative Example.

(4) Zeolite content In the above method for measuring the water equilibrium adsorption amount, the water equilibrium adsorption amount of pure 4A type zeolite powder was 28.0%. The water-equilibrated adsorption amount (A) of the molded product obtained by firing and activating the molded product which was washed with pure water and dried after binderless conversion was calculated, and the zeolite content was calculated by the following formula.

Zeolite content (%) = A / 28.0 × 100 (5) Ion exchange rate After the ion-exchanged molded body was completely dissolved using nitric acid and hydrofluoric acid, an ICP emission spectrometer (Perkin Elmer Manufactured by the company, model Optima 3000), sodium,
Example 1 Synthetic sodium A type zeolite powder (manufactured by Tosoh Corporation, SiO ₂ / Al ₂ O ₃ =) in which the content of ion exchanged cations was measured and the ion exchange rate was calculated from the mole fraction of exchanged cations with respect to total cations 2.0) 4.5 parts by weight of sodium tripolyphosphate based on P ₂ O ₅ dissolved in 30 parts by weight of Georgia Kaolin clay and 50 parts by weight of water based on 100 parts by weight of a mixed muller kneader (Shinto Kogyo Co., Ltd.) Sufficiently mixed and kneaded with the product, model: MSG-05S).
The bulk density of the obtained mixture was measured by the above method, and was found to be 0.98 kg / liter.

This mixture was granulated into beads by using a blade-stirring type rolling granulator Henschel mixer (manufactured by Mitsui Mining Co., Ltd., model: FM-75).

Particles having a particle size of 1.7 to 2.4 mm were classified from this molded product using a sieve, and then sized using a Marumerizer molding machine (manufactured by Fuji Paudal Co., model: Q-1000). 650 in a muffle furnace (manufactured by Advantech, model: KM-600) under air circulation.
The clay was sintered for 5 hours in an atmosphere of ℃ to metakaolinize.

100 g of this calcined product and 400 cc of 7 wt% sodium hydroxide aqueous solution were put in a stainless steel container with a lid of 1 liter and dried in a hot air dryer at 40 g.
After aging for 1 hour at 80 ° C. and crystallization for 4 hours at 80 ° C., it was thoroughly washed with pure water and dried.

Then, 30 g of the dried molded body
A muffle furnace (manufactured by Advantech, model: KM-6
00) in air at 600 ° C. in an atmosphere of 5
Zeolite content was calculated from the water content equilibrium adsorption amount measured by the above method for the binderless zeolite bead molded body obtained by calcination for a long time for activation, and the results are shown in Table 1.

Further, 50 g of a dried molded body after binderless formation and 50 g of anhydrous form were prepared, and an aqueous solution of potassium chloride prepared to a liquid concentration of 0.5 N was added to polyethylene in an amount of 3 times equivalent to the aluminum ion in the molded body. Put in a container, 2 at room temperature
After performing ion exchange once for 4 hours, it was thoroughly washed with pure water and dried, and then a muffle furnace (manufactured by Advantech, model:
KM-600) and activated by baking for 5 hours in an atmosphere of 600 ° C. under air flow, and the obtained binderless zeolite bead molded body was subjected to ion exchange rate, pressure resistance, and water equilibrium adsorption amount by the above-mentioned method. The measurement results are shown in Table 2.

[0058]

[Table 1]

[Table 2] In Tables 1 and 2, the amount of clay refers to zeolite 100.
The amount of the inorganic dispersant is the amount of P ₂ O ₅ and Al ₂ O ₃ with respect to 100 parts by weight of the zeolite. The types of inorganic dispersants used are: A: sodium tripolyphosphate (Na ₅ P ₃ O ₁₀ ), B: sodium pyrophosphate (Na ₄ P ₂ O ₇ ), C: sodium aluminate (Na ₂ Al ₂ O ₄ , D: Potassium pyrophosphate (K ₄ P
₂ O ₇ ) is shown.

In the ion exchange, an aqueous solution prepared by dissolving chlorides of exchange cations (special grade reagent) in pure water was used.

Examples 2 to 10 Georgia Kaolin clay shown in Table 1, inorganic dispersant,
A binderless zeolite bead molded body was prepared in the same manner as in Example 1 except for the type of cellulose derivative, the number of mixed parts, and ion exchange conditions. The bulk density of the mixture obtained by the mixing and kneading was measured by the above method, and the result was in the range of 0.88 to 0.99. After granulation molding,
The zeolite content, the ion exchange rate, the pressure resistance, and the water equilibrium adsorption amount of the binderless zeolite bead molded product obtained by firing, binderless formation, ion exchange, and activation were measured by the same method as described above.

Comparative Examples 1 to 11 Comparative Examples 1 to 10 are the types and addition amounts of the Georgia kaolin clay, inorganic dispersant, and cellulose derivative shown in Table 1.
Binderless zeolite bead moldings were prepared in the same manner as in Example 1 except for the presence or absence of binderless and ion exchange conditions. Further, the bulk density of the mixture obtained by the mixing and kneading was measured by the above-mentioned method, and the result was 0.83 to
It was in the range of 0.95.

Comparative Example 11 follows the method described in Example 4 of JP-A-10-87322, and Comparative Example 12
In the same manner, a zeolite bead molded body was prepared by changing only the number of kaolin-based clay within the range of the present invention by the same method.

Further, a binderless zeolite bead molded body was prepared from these zeolite bead molded bodies in the same manner as in Example 1, and the obtained molded body was determined from the water content equilibrium adsorption amount measured by the above method to determine the zeolite content. Was calculated and the results are shown in Table 3.

Further, as in Example 1, an alkali metal,
The ion exchange rate, pressure resistance, and water equilibrium adsorption amount of the molded body obtained by ion exchange using an alkaline earth metal chloride were measured by the methods described above, and the results are shown in Table 4.

[0065]

[Table 3]

[Table 4] In Tables 3 and 4, the amount of clay refers to zeolite 100.
An amount of the inorganic dispersant is an amount of P ₂ O _{5 with} respect to 100 parts by weight of zeolite. The type of inorganic dispersant used is A: sodium tripolyphosphate (Na ₅ P ₃ O ₁₀ ).

In the ion exchange, an aqueous solution prepared by dissolving chlorides of the exchanged cations (special grade reagent) in pure water was used.

In Comparative Example 8, the condensed phosphate was not completely dissolved in the water used in the mixing and kneading step and was added in the form of a slurry, so that the mixture became non-uniform and could not be molded into a uniform bead shape.

In Comparative Example 9, since the thickening effect was too strong, the formed bead-like shaped articles adhered to each other and could not be uniformly shaped.

[0069]

As is clear from the above description, the binderless zeolite bead molding of the present invention has a compressive strength,
It is a molded product having a high water equilibrium adsorption amount and a high zeolite content, and exhibiting excellent adsorbent physical properties. Furthermore, the binderless zeolite bead molded product of the present invention can be obtained by the production method of the present invention.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C01B 39/14 C01B 39/14 39/22 39/22 F term (reference) 4D052 AA00 GA04 GB12 GB13 GB16 GB17 HA03 HA24 HB02 4G004 FA00 JA02 4G066 AA12D AA50D AA62B AA63A AC02D BA09 BA35 BA36 CA43 DA01 DA07 FA03 FA18 FA22 FA26 FA37 4G073 BA01 BA02 BA04 BA05 BA70 BB78 BD20 CM09 CZ02 CZ03 CZ04 FB29 FB30 UA0627 UA27

Claims (13)

[Claims] 1. A zeolite content of 95% or more, a part or all of exchangeable sodium ions are exchanged with monovalent to trivalent cations or a mixture thereof, and a particle size of all particles. A binderless zeolite bead molded body having an average value of compressive strength of 6 mmf or more and 6 kgf or more. 2. The binderless zeolite bead molding according to claim 1, wherein the monovalent to trivalent cation is an alkali metal and / or an alkaline earth metal. 3. The binderless zeolite bead molding according to claim 1 or 2, wherein the zeolite content is 98% or more. 4. The zeolite is A type or X type.
4. The binderless zeolite bead molded product according to any one of 3 to 3. 5. Kaolin-based clay 20 to 35 parts by weight, aqueous solution of an alkaline dispersant 4 to 10 parts by weight, and / or cellulose derivative 0.5 to 5 parts by weight per 100 parts by weight of zeolite. The zeolite bead formed body formed by tumbling granulation from a mixture with a part of the mixture is fired, and then contacted with a sodium hydroxide aqueous solution to form a binderless form, ion exchange, and activation. 1. A method for producing a binderless zeolite bead molded body according to claim 1. 6. The method for producing a molded zeolite bead according to claim 5, wherein the bulk density of the mixture is 0.8 to 1.0 kg / liter. 7. The method for producing a molded zeolite bead according to claim 5, wherein the kaolin-based clay in the mixture has a primary particle diameter of 1 μm or less. 8. The method for producing a molded zeolite bead according to claim 5, wherein the inorganic dispersant is a condensed phosphate and / or an aluminate. 9. The method for producing a molded zeolite bead according to claim 8, wherein the condensed phosphate is one or more selected from the group consisting of sodium tripolyphosphate, sodium pyrophosphate and potassium pyrophosphate. 10. The method for producing a zeolite bead molded body according to claim 8, wherein the aluminate is sodium aluminate. 11. The method for producing a binderless zeolite bead molded article according to claim 5, wherein the cellulose derivative is one or more selected from the group consisting of carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl methyl cellulose, hydroxypropyl cellulose and ethyl cellulose. 12. A method for adsorbing and removing a substance to be adsorbed in a gas or a liquid, which comprises using the binderless zeolite bead molded body according to any one of claims 1 to 4. 13. The adsorption removal method according to claim 12, wherein the substance to be adsorbed is water.