KR20090122027A - Process for preparing spherical zeolite granule - Google Patents

Abstract

PURPOSE: A spherical zeolite molding body and a manufacturing method thereof are provided to offer improved mechanical intensity with high shape density by forming pores inside the molding body. CONSTITUTION: A manufacturing method of a spherical zeolite molding body comprises the following steps of: manufacturing the spherical zeolite molding body by mixing colloidal silica aqueous solution with a compound in which zeolite powder and cellulose-based compound are included; separating the spherical zeolite molding body having a particle diameter of 0.50 ~ 3.35 mm; manufacturing the spherical molding body in which the cellulose-based compound is removed; reacting an alkali aqueous solution and a sodium aluminate aqueous solution with the spherical molding body; ion-exchanging the spherical molding body with the alkali metal salt or alkaline-earth metal salt; and sintering the ion-exchanged spherical molding body at a temperature of 350 ~ 650 °C.

Description

Spherical zeolite molded body and its manufacturing method {Process for preparing spherical zeolite granule}

The present invention exhibits excellent nitrogen adsorption capacity, abrasion resistance and external density by mixing colloidal silica aqueous solution and cellulose compounds as inorganic binders of zeolites, thereby providing pressure swing adsorption (PSA) method, vacuum swing adsorption (VSA) method and heat. The present invention relates to a spherical zeolite molded body which can be very usefully applied as an adsorbent of a high purity oxygen generator such as a swing adsorption (TSA) method and a method of manufacturing the same.

In the conventional method of producing oxygen by the deep cooling method, oxygen is prepared by cooling the air to -200 ° C to liquefy, rectifying and separating using a boiling point difference between oxygen and nitrogen. This method of oxygen production requires large-scale equipment and high energy costs, so that the apparatus may be installed in a place where a large amount of gas is used, for example, a steel mill or a chemical plant, but in a place where a small amount of gas is used. Rather than installing and using the device directly, it was necessary to use liquefied or bombed and transported and supplied oxygen.

Examples of the oxygen production method which improves the depth cooling method include a pressure swing adsorption (PSA) method, a vacuum swing adsorption (VSA) method and a thermal swing adsorption (TSA) method.

PSA method, VSA method and TSA method are based on the principle that the adsorbent in the apparatus adsorbs gas during the pressurization process, and the adsorbed gas is easily desorbed and regenerated during the depressurization process. This method has the advantage that the manufacturing apparatus can be installed to maintain a certain distance from the use environment of the oxygen, the required amount can be manufactured and used immediately, and can supply oxygen easily and semi-permanently at a low cost. In addition, the adsorbents of the oxygen generating apparatus by the PSA method and the VSA method should be excellent in the selective adsorption capacity for nitrogen and a large difference in the adsorption amount of nitrogen and oxygen, synthetic zeolite can be used as a representative example.

Zeolite is a crystalline aluminosilicate represented by the following formula (1).

M _{x / n} [(AlO ₂ ) _x (SiO ₂ ) _y ] .wH ₂ O

 In Formula 1, M is a cation; n is valency; w represents the number of molecules of the crystallized water; x and y are constants that change depending on the crystal structure.

In general, the zeolite has a pore diameter of about 3 to 10 Å, and exhibits a molecular sieve effect. Due to this structure, the zeolite has a unique property of selectively adsorbing nitrogen molecules in the air. In particular, as a hydrophilic adsorbent, the adsorption power with a polar molecule such as water is strong, and there is an advantage that the adsorption power is high even at low partial pressure and high temperature. However, although the zeolite has the above selective adsorption characteristics, the average particle diameter is in the form of a fine powder of several micrometers, which causes many inconveniences in the adsorption or catalytic process for handling liquid reactants. Therefore, in order to use zeolite as a useful adsorbent in a gas generator, it is required to go through a process of forming a certain form by adding a binder.

Commonly known methods for shaping zeolites include zeolites ion-exchanged with a suitable cation, dried and then granulated and molded by adding up to about 30% by weight of binder per particle, followed by firing at a temperature in the range of 600 to 800 ° C. Processes for producing are well known. As a prior art of such a method, 4A type zeolite powder is converted to 5A type zeolite by converting calcium ions into a 5A type zeolite, followed by injection, molding, and firing by using kaolinite, which is a natural clay, as an inorganic binder. Techniques for preparing the same are known [US Pat. Nos. 5,001,098 and 5,292,360 and the like]. However, the technique has a disadvantage in that the process of filtration and washing is difficult because the zeolite particles of several to several tens of micrometers generated after ion exchange exist in a slurry phase. In addition, the natural clay, which serves as a binder added to increase the mechanical strength, was included in the final product as it had a disadvantage in that the adsorption performance was lowered.

In order to improve the above disadvantages, US Patent No. 6,743,745 describes a manufacturing method for minimizing the amount of the binder by blending about 2 to 15% by weight of highly dispersed attapulgite (10 wt. The highly dispersed clay component of about% is contained as it is as an inert component, and the highly dispersed clay component is enclosed in the state of capturing the zeolite component, thereby preventing the gas component to be separated from spreading into and out of the molded body. Therefore, there is a disadvantage in that the adsorption / desorption speed, which is important in the PSA method or the VSA method, is limited.

On the other hand, U.S. Patent No. 4,603,040 uses a kaolin-based binder to prepare a zeolite molded body, and then calcined at 600 ° C. or higher and treated for 10 days or more in an aqueous alkali solution to convert the binder component into zeolite, thereby improving the adsorption performance. While a method of making shaped articles is shown, it is a difficult method to implement industrially.

As a technology for improving the manufacturing method, Korean Patent No. 538,961 discloses about 15% by weight of natural clays (kaolin-based and montmorillonite-based) as binders and calcined at about 600 ° C., followed by mixing with sodium hydroxide and potassium hydroxide. A process for producing low silica X type granular aggregates with low proportions of inert binders by treatment within 24 hours is described. However, since the method also uses natural clay as a binder, the mechanical strength of the zeolite molded body is reduced due to the shrinkage of the clay during the firing process, so that dust generation is severe, and the specific surface area is reduced, so that the adsorption capacity is reduced, high purity oxygen is generated. There is a limit to the application to the device.

The present invention aims to solve the problem of difficulty in filtration and washing of the conventional clay binder used as an inorganic binder of zeolite, a problem of poor mechanical strength and adsorption capacity.

Another object of the present invention is to provide a spherical zeolite molded body which can be usefully applied as an adsorbent of a high purity oxygen generator and a manufacturing method thereof.

The present invention provides a method for producing a spherical zeolite molded body, comprising: one step of spray-mixing an aqueous colloidal silica solution to a mixture of a zeolite powder and a cellulose compound to produce a spherical molded body; Two steps of classifying only spherical shaped bodies having a particle size in the range of 0.50 to 3.35 mm in the spherical shaped bodies; Three steps of manufacturing the spherical shaped body from which the cellulose-based compound is removed by drying the classified spherical shaped body and then baking it at a temperature range of 400 to 650 ° C .; 4 steps of putting the spherical shaped body from which the cellulose-based compound has been removed into an aqueous solution of an aqueous alkali solution and sodium aluminate and hydrothermally reacting; 5 steps of ion-exchanging the spherical shaped body subjected to the hydrothermal reaction with an aqueous solution of an alkali metal salt or an alkaline earth metal salt; And six steps of firing the ion-exchanged spherical shaped body at a temperature in the range of 350 to 650 ° C. to solve the above problems by providing a method for producing a spherical zeolite shaped body.

Moreover, this invention solves the said subject by providing the spherical zeolite molded object manufactured by the said manufacturing method.

The present invention provides a simple and easy method for producing a spherical zeolite molded body, contains almost no inert binder component, the pores are well formed inside the molded body excellent in adsorptive separation performance, high appearance density, excellent mechanical strength There is an effect that a spherical zeolite molded body can be obtained.

In addition, the present invention provides a spherical zeolite molded body having a macro pore volume of 0.15 to 0.32 ml / g having a size of 50 to 500 nm, thereby allowing the liquid reactant to penetrate therein to provide a binder component. It has the effect of being easily converted to the type of zeolite.

Therefore, the spherical zeolite molded body according to the present invention has a useful effect as an adsorbent of a high purity oxygen generator by PSA, VSA and TSA methods.

 Conventional adsorbents for oxygen generators are prepared by blending clay-based inorganic binders with zeolite powder and molding them, or by firing, or by converting the clay-based inorganic binder components into zeolites by treating the calcined granular composition with an aqueous alkali solution. However, impurities mixed in the clay-based inorganic binder are mixed in the granular composition as it is, and there is a limit in improving the adsorptive separation performance and mechanical strength.

Therefore, the present invention uses a colloidal silica aqueous solution as an inorganic binder to the zeolite and adds a cellulose-based compound that can act as a skeleton so that agglomeration can occur well in the molding process to prepare a spherical shaped body, and calcined cellulite By removing the Rhodes compound component and forming a macro pore to allow the liquid reactant to penetrate into the spherical body well, and then treated with aqueous sodium aluminate solution to directly convert the inorganic binder component silica to the desired zeolite A spherical zeolite molded body was produced.

As a result, pores are well formed inside the molded body with little inert binder component, thereby producing a novel spherical zeolite molded body having excellent adsorptive separation performance, high appearance density, and excellent mechanical strength. The spherical zeolite molded body according to the present invention is expected to be very usefully applied as an adsorbent for oxygen generating apparatuses by PSA method, VSA method and TSA method which must continuously supply a large amount of high purity oxygen.

Referring to the present invention in more detail as follows.

The present invention provides a method for producing a spherical zeolite molded body, comprising: one step of spray-mixing an aqueous colloidal silica solution to a mixture of a zeolite powder and a cellulose compound to produce a spherical molded body; Two steps of classifying only spherical shaped bodies having a particle size in the range of 0.50 to 3.35 mm in the spherical shaped bodies; Drying the classified spherical shaped bodies and then firing them in a temperature range of 400 to 650 ° C. to produce spherical shaped bodies from which the cellulose compounds are removed; 4 steps of putting the spherical shaped body from which the cellulose-based compound has been removed into an aqueous solution of an aqueous alkali solution and sodium aluminate and hydrothermally reacting; 5 steps of ion-exchanging the spherical shaped body subjected to the hydrothermal reaction with an aqueous solution of an alkali metal salt or an alkaline earth metal salt; And 6 step of baking the ion-exchanged spherical shaped body in the temperature range of 350 ~ 650 ℃; It provides a spherical zeolite molded body comprising a spherical zeolite molded body made of the above, and is produced by the above production method, exhibiting excellent nitrogen adsorption capacity, wear resistance and appearance density can be very useful as an adsorbent of a high purity oxygen generator.

The first step is to shape the zeolite into a spherical shape. After mixing the zeolite powder and the cellulose compound into a molding apparatus and mixing, the colloidal silica aqueous solution is kneaded while spraying through a nozzle to produce a spherical shaped body. The spherical shaped bodies thus produced had a particle diameter of 0.20 to 5.0 mm.

In the present invention, a zeolite selected from NaA zeolite, NaX zeolite and Na-K-low silica X zeolite can be used as the zeolite, and they have micropores in the crystal and thus exhibit a unique molecular sieve effect of adsorbing molecules. . In addition, microcrystalline cellulose (MC) may be more preferably used as the cellulose compound. The microcrystalline cellulose refers to a cellulose-based compound that does not contain alkali metal ions and exhibits water insoluble properties.

As the mixture of the zeolite powder and the cellulose compound, 80 to 95 wt% of the zeolite powder and 5 to 20 wt% of the cellulose compound may be used. In this case, when the content of the cellulose-based compound is less than 5% by weight, it is difficult to form a sphere, and when it exceeds 20% by weight, the appearance density is lowered and the strength of the molded body is lowered.

On the other hand, the colloidal silica aqueous solution can be used containing a silica (SiO ₂ ) solid content of 25 to 35% by weight, when the content of silica solid content of the aqueous colloidal silica solution is less than 25% by weight of the spherical zeolite molded body If the bonding strength is weak and exceeds 35% by weight, the viscosity of the solution is high, making normal spraying through the nozzle difficult.

In addition, the spherical molding apparatus is not particularly limited to a molding apparatus generally used in the art, but, for example, selected from among a flow share mixer, a disc granulator, an injection molding granulator, a fluidized bed granulator, and a compression crushing granulator. Can be.

The second step is a classification step, in which a spherical molded product prepared above is classified with a classifier to take only spherical shaped bodies having a size of 0.50 to 3.35 mm, more preferably 1.30 to 2.46 mm. At this time, the spherical shaped body out of the particle size range can be recycled and re-introduced into the molding apparatus of the first step, mixed with the zeolite newly introduced, and used as a nucleus in the molded body manufacturing process. Thus, the zeolite powder of step 1 may comprise 40 to 90% by weight of the pure zeolite powder, and 10 to 60% by weight of the spherical shaped body recycled and generated in step 2, the spherical shaped body to be recycled out of the range When mixed, the granulation process is difficult and can cause a difficult assembly process.

As a result, the present invention can easily control the size of the molded body in the granulation process that is difficult to control the particle size by the classification and recirculation process, and can be manufactured close to the sphere to minimize the porosity during the filling in the adsorption tower of the oxygen generator. There is an advantage.

The third step is a step of manufacturing the spherical molded body from which the cellulose-based compound is removed by drying the classified spherical molded product and then firing it in a temperature range of 400 to 650 ° C. The firing is carried out by firing at a temperature in the range of 400 ~ 650 ℃ in the air, if the firing temperature is lower than the range may cause a problem that the organic matter is not removed well, if higher than the range the silica component on the zeolite crystal surface It will stick too hard to reduce the reactivity to convert to zeolite.

The fourth step is a step of converting the silica component contained as a binder into a desired type of zeolite by placing the spherical shaped body from which the cellulose-based compound has been removed into an aqueous alkali solution and an aqueous solution of sodium aluminate and hydrothermally reacting. The composition of the aqueous alkali solution and the aqueous solution of sodium aluminate is not particularly limited to those commonly used in the art, but may be, for example, the composition of a conventional hydrothermal reaction process for converting a silica component, which is a binder component, into a zeolite. More specifically, the aqueous alkali solution may be used sodium hydroxide and potassium hydroxide.

In addition, the spherical shaped body from which the cellulose compound is removed may be put in an aqueous alkali solution and an aqueous sodium aluminate solution, and aged at about 20 to 50 ° C. for about 6 to 24 hours. At this time, if the aging temperature is too low, the treatment time is long, and the production efficiency of the spherical zeolite molded body is lowered. If the aging temperature is too high, the seed of the zeolite is not formed, and it proceeds directly to the crystallization process. The conversion to zeolite is lowered. After undergoing a suitable aging process as described above, the reaction mother liquor is removed after 4 hours of hydrothermal reaction in the range of 70-95 ° C., followed by washing with water sufficiently. If the temperature of the hydrothermal reaction is less than 70 ℃ hydrothermal reaction occurs very slowly, if it exceeds 95 ℃ may be a problem that the crystallization is rapidly progressed to produce a mixture of various types of zeolite.

Scheme 1 shows the specific chemical reactions occurring when the binder component, silica (SiO ₂ ), is treated with an aqueous solution of alkaline aqueous solution and sodium aluminate in order to convert to a desired type of zeolite.

According to Scheme 1, since most of the silica component, which serves as a binder and has almost no adsorptive separation ability, is converted to zeolite, the adsorptive separation performance of the spherical shaped body is improved by this process. In addition, since the reaction mother liquor is easily penetrated into the macropores present in the spherical shaped body before the reaction treatment, the zeolite produced is present in the pores as it is, thereby increasing the appearance density and strength of the spherical shaped body. Let's go.

The fifth step is a step of ion-exchanging the spherical shaped body subjected to the hydrothermal reaction with an aqueous solution of an alkali metal salt or alkaline earth metal salt. As aqueous solution of the said alkali metal salt or alkaline-earth metal salt, the aqueous solution containing lithium ion and calcium ion can be used more preferably. That is, the process of ion-exchanging cations (Na ⁺ and K ⁺ ) present in the zeolite crystal lattice with Li ⁺ ions or Ca ²⁺ ions by treating the spherical shaped body undergoing hydrothermal reaction with an aqueous solution containing lithium ions or calcium ions. to be. At this time, LiCl aqueous solution may be used as the lithium ion aqueous solution, and CaCl ₂ aqueous solution may be used as the calcium ion aqueous solution. The spherical shaped body subjected to the ion exchange treatment as described above is dried after washing with water sufficiently. The drying conditions are not particularly limited to conditions generally known in the art, but may be more preferably carried out at room temperature or at a temperature of 60 to 110 ℃ and atmospheric pressure conditions.

The final sixth step is to fire the ion-exchanged spherical body at a temperature in the range of 350 to 650 ° C., in which the ion-exchanged spherical body is put into a continuous firing apparatus and sufficiently infused with air from which moisture and carbon dioxide are removed. While being activated at 350 to 650 ° C, more preferably at 400 to 550 ° C for 0.3 to 3.0 hours to produce the desired final spherical zeolite shaped body. At this time, if the firing temperature is less than 350 ℃ crystal water is not removed well, if the firing temperature exceeds 650 ℃ adsorption capacity is reduced due to the pore sintering phenomenon of the spherical zeolite molded body.

The firing device is not particularly limited to a device generally used in the art, but for example, a rotary kiln, a batch firing furnace, a tunnel firing furnace, a high frequency heating furnace, a dissociation furnace firing furnace, or the like can be used.

The spherical zeolite shaped bodies produced by the present invention may be A-type zeolites, X-type zeolites and low silica X-type zeolites ion-exchanged with alkali metal salts or alkaline earth metals. In addition, the spherical zeolite molded body may be made of 93.0 to 99.9% by weight of zeolite and 0.1 to 7.0% by weight of silica.

The spherical zeolite molded body has a nitrogen adsorption capacity of 0.85 ml / g or more (more specifically, 0.85 to 1.20) at 25 ° C. and 1 Torr, and abrasion resistance (8 ㅧ 12 ASTM Mesh) of 98% or more (more specifically, 98.0 to 99.5) The external density (8 ㅧ 12 ASTM Mesh) is 0.62 g / ml or more (more specifically, 0.62 to 0.70), and the oxygen is stored at room temperature and atmospheric pressure (NTP) as a result of being charged and operated in an adsorption tower of an oxygen generator according to the PSA method. The amount generated was 6.2 ml / min or more (more specifically, 6.2 to 8.0) per unit mass (g) of the spherical zeolite molded body. Therefore, the spherical zeolite molded body according to the present invention has a useful effect as an adsorbent of a high purity oxygen generator by PSA, VSA and TSA methods.

If the present invention will be described in detail based on the embodiment as follows, the present invention is not limited by the embodiment.

EXAMPLE

Example 1

130 g of 9.7 kg (25% by weight of water) and 0.8 kg of microcrystalline cellulose (MC) and zeolite spherical bodies (recycled to 1.30 mm) recycled to 8.2 kg of NaA type zeolite powder (5.4% by weight of water) The powder was mixed in a sized flow share mixer (manufactured by L'dige, Germany) for 1 minute at a spindle speed of 180 rpm and a chopper speed of 3600 rpm. Subsequently, 5.5 kg of colloidal silica aqueous solution (SiO ₂ : 30% by weight) and 0.5 kg of water were mixed and kneaded while injecting the powder mixture through a nozzle, followed by spherical molding for 15 minutes, and the particle size was 0.20∼ A spherical molded body of 5.0 mm was obtained.

The spherical shaped bodies were classified into a vibratory classifier to obtain 14.8 kg of spherical shaped bodies having a size of 1.30 to 2.46 mm, and spherical shaped bodies of 1.30 mm or less were recycled and used in a molding process. Was used.

The spherical shaped bodies of 1.30 to 2.46 mm separated in the above classification process were dried in a fluidized bed dryer at 90 ° C., placed in a rotary kiln (manufactured by Lindberg, USA) maintained at 600 ° C., continuously fired, and allowed to stand in the air. 10.9 kg of spherical shaped bodies (NaA type) were obtained.

The spherical molded body thus obtained was added to 21.8 kg of water, 2.2 kg of sodium hydroxide and 1.7 kg of sodium aluminate, and dissolved in an aqueous solution, and aged at 35 ° C for 12 hours. Next, the temperature of all reactants was raised to 90 ° C. and subjected to hydrothermal reaction for 8 hours, after which the reaction mother liquor was removed and washed with water sufficiently.

2 M CaCl ₂ aqueous solution was heated to 70 ° C. to a spherical molded body subjected to hydrothermal reaction, contacted at a flow rate of 1.2 L / min, ion-exchanged, and sufficiently washed with water, followed by drying in a fluidized bed dryer at 90 ° C.

The ion-exchanged spherical shaped body is placed in a rotary kiln (manufactured by Lindberg, USA) maintained at 500 ° C, continuously fired with sufficient water and carbon dioxide-free air, and then activated by flowing high-purity nitrogen in an airtight container. 8.3 kg (CaA type) of the obtained spherical shaped body were obtained.

Example 2

8.2 kg of NaX type zeolite powder (5.2 wt% of water content) is used during the molding process, 2.2 kg of sodium hydroxide and 1.1 kg of sodium aluminate are used for 21.8 kg of water in the hydrothermal reaction process, and 2 M LiCl is used during ion exchange. Except for treating with an aqueous solution was carried out under the same conditions as in Example 1 to obtain 8.0 kg of a spherical shaped body (LiX type).

Example 3

In the molding process, 8.2 kg of Na-K-low silica X-type zeolite powder (5.2 wt% of water content) was used, and in the hydrothermal reaction, 21.8 kg of water, 1.6 kg of sodium hydroxide, 0.6 kg of potassium hydroxide, and sodium aluminate 1.8 kg was used, and 8.1 kg of a spherical shaped body (Li-low silica X-type) was obtained under the same conditions as in Example 1 except that it was treated with an aqueous 2 M LiCl solution in the ion exchange process.

Comparative Example 1

Granular zeolite compacts (particle size 1.30 mm or less), recycled to 7.2 kg NaA-type zeolite powder (5.4 wt% water), 10.5 kg (26 wt% water content), 0.19 kg of montmorillonite clay, and 1.08 kg of kaolin clay 130 l Powder was mixed into a flow share mixer (manufactured by L'dige, Germany) for 1 minute at a spindle speed of 180 rpm and a chopper speed of 3600 rpm. Subsequently, 3.4 kg of water was kneaded while injecting the powder mixture through a nozzle, followed by granulation for 15 minutes, thereby obtaining an irregular granular molded body having a particle diameter of 0.1 to 7.0 mm.

The granular compacts were classified by vibrating classifier to obtain 11.8 kg of granular compacts of 1.30 to 2.46 mm. The granular compacts of 1.30 mm or less were recycled to the molding process, and the granular compacts of 2.46 mm or larger were crushed after drying. Recycle was used.

The granular compacts having a size of 1.3 to 2.46 mm separated in the classification process were dried in a fluidized bed dryer at 90 ° C., placed in a rotary kiln (manufactured by Lindberg, USA) maintained at 600 ° C., continuously fired, and then sufficiently left in the air. To give 9.1 kg of a granular molded body (NaA type).

The granular molded product thus obtained was added to an aqueous solution in which 2.5 kg of sodium hydroxide and 0.5 kg of sodium aluminate were added to 18.2 kg of water, followed by aging at room temperature for 12 hours. Next, the temperature of all reactants was raised to 90 ° C. and subjected to hydrothermal reaction for 8 hours, after which the reaction mother liquor was removed and washed with water sufficiently.

2 M CaCl ₂ aqueous solution was heated to 70 ° C. to a granular molded article subjected to hydrothermal reaction, contacted at a flow rate of 1.2 L / min, ion-exchanged, and sufficiently washed with water, followed by drying in a fluidized bed dryer at 90 ° C.

The ion-exchanged granular shaped body was placed in a rotary kiln (manufactured by Lindberg, USA) maintained at 500 ° C, continuously fired with sufficient water and carbon dioxide-free air, and activated by flowing high-purity nitrogen in a sealed container. 7.1 kg (CaA type) were obtained of the processed granular molded object.

Comparative Example 2

7.2 kg of NaX zeolite powder (5.2 wt% of water content) is used in the molding process, 2.7 kg of sodium hydroxide and 0.2 kg of sodium aluminate are used in 18.2 kg of water during the hydrothermal reaction, and 2 M LiCl is used during ion exchange. 6.8 kg of a granular molded body (LiX type) was obtained under the same conditions as in Comparative Example 1 except that the solution was treated with an aqueous solution.

Comparative Example 3

In the shaping process, 7.2 kg of Na-K-low silica X-type zeolite powder (5.2 wt% of water content) was used, and in hydrothermal reaction, 18.2 kg of water, 1.8 kg of sodium hydroxide, 0.9 kg of potassium hydroxide, and 0.4% of sodium aluminate were used. kg was used, and 7.0 kg of a granular molded product (Li-low silica X-type) was obtained under the same conditions as in Comparative Example 1 except that it was treated with an aqueous 2 M LiCl solution in an ion exchange process.

Experimental Example

Physical properties of the samples prepared in Examples 1 to 3 and Comparative Examples 1 to 3 were measured by the following method. The results are shown in Table 1 below.

1) Determination of nitrogen adsorption capacity: The sample was degassed at 350 ° C. for a sufficient time and calculated by calculating the nitrogen adsorption isotherm from 25 ° C. to 760 torr. At this time, Table 1 below describes the nitrogen adsorption capacity at 25 ° C. and 745 torr.

2) Wear resistance measurement: The wear resistance of the sample was measured according to the hardness test method of the granular material of KS-M-1802 (JIS-K-1474). In the test, the sample was put together with a steel ball, shaken in a hardness test vessel, classified, and the mass of the sample remaining in the upper part was measured, and the hardness value was calculated from the mass ratio with the first sample.

H = (W ÷ S) × 100

In Equation 1, H is a wear resistance (hardness,%); W is the weight in grams of sample remaining on top of the sieve; S is the sum of the weight of the sample remaining in the standard and the weight of the sample remaining in the receiving vessel (g).

3) Bulk density measurement: 100 samples After putting in a ml flask and tapping sufficiently at a certain height, the volume (V, ml) and weight (W, g) were measured and calculated from the following equation.

External Density = W / V

4) Oxygen generation measurement: To measure the oxygen separation performance of the sample, an oxygen generator adopting a two-way atmospheric regeneration method was used. The test method is as follows.

Air was blown into each adsorption vessel filled with 9.0 kg of adsorbent only with an air compressor to pressurize to 3 kgf / cm 2 to perform adsorption. At this time, each of the adsorption vessels was repeatedly operated periodically to increase the pressure, adsorption, backwashing, and depressurization to generate oxygen, and the time of one process was about 2 minutes. The concentrated oxygen is flowed through a flowmeter to measure the flow rate and sent to an oxygen analyzer (Teledyne, 326AI20-2X) to measure the concentration of oxygen, converting pure oxygen into volume (ml) in NTP, and adsorbent unit mass (g) Based on the calculation.

Test Items Nitrogen adsorption capacity (mmol / g) Wear resistance (%) External density (g / ml) Oxygen generation amount (ml / g) Example 1 0.89 99.0 0.66 6.5 Comparative Example 1 0.73 97.2 0.62 5.3 Example 2 0.90 99.2 0.65 6.6 Comparative Example 2 0.74 97.1 0.61 5.4 Example 3 1.10 99.1 0.65 7.5 Comparative Example 3 0.87 96.7 0.61 6.1

As shown in Table 1, by using a colloidal silica aqueous solution and a cellulose compound as a mixed inorganic binder of the zeolite to prepare a spherical zeolite molded body, it is a granular zeolite molded body manufactured using a conventional clay binder In comparison with Comparative Examples 1-3, it was confirmed that it showed the outstanding nitrogen adsorption capacity, abrasion resistance, and external density. As a result, the spherical zeolite molded body according to the present invention is expected to be very useful as an adsorbent of a high purity oxygen generator.

Claims (11)

In the method for producing a spherical zeolite molded body, 1) one step of spray-mixing an aqueous colloidal silica solution to a mixture of a zeolite powder and a cellulose compound to produce a spherical shaped body; 2) two steps of classifying only spherical shaped bodies having a particle diameter in the range of 0.50 to 3.35 mm in the spherical shaped bodies; 3) three steps of drying the classified spherical shaped bodies and firing them at a temperature in the range of 400 to 650 ° C. to produce spherical shaped bodies from which the cellulose compounds are removed; 4) 4 steps of putting the spherical shaped body from which the cellulose-based compound has been removed into an aqueous alkali solution and an aqueous sodium aluminate solution, followed by hydrothermal reaction; 5) 5 steps of ion-exchanging the spherical shaped body subjected to the hydrothermal reaction with an aqueous solution of an alkali metal salt or alkaline earth metal salt; And 6) firing the ion-exchanged spherical shaped bodies in a temperature range of 350 to 650 ° C .; Method of producing a spherical zeolite molded body comprising a. 2. The method of claim 1, wherein the zeolite of step 1 is selected from NaA zeolite, NaX zeolite, and Na-K-low silica X zeolite. The method of manufacturing a spherical zeolite molded body according to claim 1, wherein the cellulose compound of step 1 is microcrystalline cellulose. The spherical zeolite molded body according to claim 1, wherein the mixture of the zeolite powder and the cellulose compound of step 1 is made by mixing 80 to 95 wt% of the zeolite powder and 5 to 20 wt% of the cellulose compound. Manufacturing method. The method of claim 1, wherein the zeolite powder of step 1 comprises a spherical shaped body having a particle diameter outside the range of 0.50 to 3.35 mm generated and recycled in step 2. 6. The method according to claim 5, wherein the zeolite powder comprises 40 to 90 wt% of pure zeolite powder and 10 to 60 wt% of the spherical shaped body recycled in two steps. The method of claim 1, wherein the aqueous colloidal silica solution of step 1 comprises 25 to 35% by weight of silica (SiO ₂ ) solids. Spherical zeolite molded bodies satisfying the following conditions simultaneously: -Nitrogen adsorption capacity of 0.85 ml / g or more, -More than 98% wear resistance, -An outer density of at least 0.62 g / ml, -The amount of oxygen generated in the oxygen generating apparatus by the PSA method is not less than 6.2 ml / min per unit mass (g) of the spherical zeolite molded body. 9. The spherical zeolite molded body according to claim 8, which comprises a composition ratio of 93.0 to 99.9% by weight of zeolite and 0.1 to 7.0% by weight of silica. 10. The spherical zeolite formed body according to claim 9, which is an A-type zeolite, X-type zeolite, or low silica X-type zeolite ion-exchanged with alkali metal salt or alkaline earth metal. The spherical zeolite molded body according to any one of claims 8 to 10, which is used as an adsorbent of an oxygen generator.