KR101602926B1

KR101602926B1 - Method for Manufacturing Synthetic Zeolites using Gangue

Info

Publication number: KR101602926B1
Application number: KR1020150148080A
Authority: KR
Inventors: 이경우; 정유식; 신희용
Original assignee: 주식회사 지엔티엔에스
Priority date: 2015-10-23
Filing date: 2015-10-23
Publication date: 2016-03-11
Also published as: CN106892437B; CN106892437A; WO2017069545A1

Abstract

The present invention relates to a manufacturing method of synthetic zeolites using pumice stone. More particularly, the manufacturing method of synthetic zeolites comprises the steps of: mixing pulverized pumice stone and alkaline substances in a powder form; heating the mixture so as to uniformly fuse the mixture; mixing the fused substance in a powder form with aluminum-containing substances and zeolite seeds in water; and manufacturing zeolites through ripening, crystallization, and drying processes. The pulverized pumice stone is mixed with alkaline substances after CaO content is reduced, which is a hindering substance in crystallization, to be below a certain level, and then is crystallized. Therefore, the manufacturing method of the present invention improves degree of crystallization and can produce synthetic zeolites in a large quantity while maintaining quality of zeolites to be a certain level.

Description

TECHNICAL FIELD The present invention relates to a method for producing synthetic zeolite using pumice,

The present invention relates to a method for producing synthetic zeolite using pumice, and more particularly, to a method for producing synthetic zeolite using pumice, and more particularly, to a method for producing synthetic zeolite using pumice, Zeolite seed and zeolite are mixed with water, and the zeolite is produced through aging, crystallization and drying process, wherein the crushed pumice is reduced in CaO content, which is a crystallization inhibiting substance, to a certain level or less and then mixed with an alkali substance, To a process for producing synthetic zeolite capable of improving the crystallinity and mass production and maintaining the quality of zeolite at a certain level.

Coal is a useful resource that has been used in various industries for a long time, such as thermal power plants, domestic fuels, and steel mill furnaces. The above coal is mined, and after the coal process, the remaining waste other than coal used in the industry is called a gum. Among them, the rock to be discarded due to the absence of coal components is called pumice stone. In addition to the coal mine, Includes rock to be discarded. In the case of anthracite coal mine in Korea, the pumped coal is produced in an amount almost equal to the amount of coal selected during the coal-fired process. Such pumice is a byproduct of coal mine, which is difficult to treat, and is treated as simple waste.

However, due to environmental pollution regulations, the pumice generated during the mining process is difficult to dispose of, so it is left in the coal mine and the amount is also several hundred million tons.

The composition of pumice is about 40 ~ 50% SiO ₂ , 15 ~ 25% Al ₂ O ₃ , 2 ~ 10% Fe ₂ O ₃ and other TiO ₂ , CaO, MgO, and the like. In such a composition SiO ₂ and Al ₂ O ₃ is arbitrarily useful raw materials for zeolite synthesis, it is possible to recycle the pumice is mine waste disposal, especially with zeolite.

Many methods for producing such a zeolite have been proposed, but most of them relate to a method for producing zeolite using fly ash generated in a thermal power plant. In addition, in the process for producing zeolite using conventional fly ash, the content of CaO is relatively high due to the effect of limestone introduced in the desulfurization process, and the synthesis and purity of zeolite, There is a disadvantage that it is difficult to produce zeolite in the form of an image.

In addition, since conventional hydrothermal synthesis or alkaline solution is used in the process of manufacturing the conventional zeolite, it is difficult to mass-produce it and the problem of equipment corrosion is inherent.

In addition, since the pumice components vary according to various regions, it is difficult to mass-produce zeolite having a certain quality.

Korean Registered Patent No. 10-0656177 (registered on Dec. 5, 2006) discloses a method of synthesizing NaP1 type zeolite using thermal power plant flooring. The prior art 1 includes a bottom material pretreatment step of drying the bottom material accumulated on the bottom of a boiler for thermal power plants at 90 to 110 ° C for 22 to 26 hours and then pulverizing the dried bottom material to a particle size of less than 100 μm; Mixing the pretreated bottom material with 2M to 3M of NaOH solution and synthesizing zeolite at room temperature or hydrothermal synthesis at 80 ° C to 100 ° C; And washing the synthesized zeolite with distilled water and drying at 70 to 90 ° C for 11 to 13 hours. Since the prior art 1 synthesizes zeolite by a hydrothermal synthesis method, it is not suitable as a mass production method since high-temperature and high-pressure conditions must be performed. Although the CaO content is lower than that of fly ash, it is still mixed with 9 wt% or more of the total weight. Therefore, it is difficult to produce various types of zeolite due to crystallization inhibitors under normal temperature and pressure conditions.

Chinese Patent Laid-Open No. 101850987 (published on Jun. 10, 2010; hereinafter referred to as "Prior Art 2") proposed a method for producing nanoscale zeolite 4A using low-grade carbon as raw material. In the above-mentioned prior art 2, low-grade carbon is pulverized, calcined powder is put into a NaOH solution to gel, and crystallization is carried out by using this. Since the NaOH solution is also used, it is difficult for NaOH to be mixed with the NaOH powder excessively, so that the NaOH is added to the reaction, and a process of recovering excess NaOH should be added. In addition, a cooling device for removing heat due to an exothermic reaction generated when NaOH is dissolved is required, and since a high concentration of NaOH solution is used, problems such as apparatus corrosion are inherent in a mass production process.

Korean Registered Patent No. 10-0656177 (Registered on December 5, 2006): Synthesis method of NaP1 type zeolite using thermal power plant floor material China Patent Publication No. 101850987 (published on Jun. 10, 2010): Method for producing nanoscale zeolite 4A using low-grade carbon as raw material

Accordingly, the present invention provides a process for producing a synthetic zeolite,

It is an object of the present invention to provide a method of maximizing the degree of crystallization while producing synthetic zeolite by using pumice, which is a waste generated during coal mining, while simplifying the manufacturing process.

In addition, the present invention can produce zeolite by using pumice having various component ratios, but the crystallization of the produced zeolite can be made higher than a certain level, and productivity can be improved. The present invention can be applied not only to zeolite A but also to various types of zeolite It is a way to be able to do.

According to another aspect of the present invention, there is provided a method for producing a synthetic zeolite,

A first step of pulverizing the selected pumice into a powder having a size of 30mesh or less using a continuous crusher; A second step of introducing the pumice powder of the first step into a water bath to elute and remove the CaO component as a crystallization inhibiting substance; A third step of putting the pumice pulverized material from which the CaO component has been removed in the second step into a heat treatment tank so as to heat and remove carbon and other impurities remaining in the pumice pulverized product; A fourth step of putting the pumice powder and the powdery alkali substance heat-treated in the third step into a stirrer and uniformly stirring the charged mixed powder; A fifth step in which the mixed powder uniformly stirred through the fourth step is introduced into a heating tank to be heated and fused with the pumice pulverized by heat; A sixth step of mixing water, an aluminum source and a zeolite seed with a fusion product obtained by performing the fusion step in the fifth step; A seventh step of aging the mixture of the sixth step while heating at 20 to 60 캜 at a low temperature while stirring; Elevating the heating temperature of the aged mixture in the seventh step to 80 to 100 占 폚 to crystallize the zeolite crystals so as to effect crystallization; And a ninth step of filtering, washing and drying the zeolite synthesized in the eighth step to produce a product.

The pumice may be a menopause produced in an abandoned mine.

The second step may further include a second step (2-1) of pouring the pumice powder into a water bath to elute and remove the CaO component, which is a crystallization inhibiting substance; And (2-2) dehydrating the pumice pulverized product having reduced CaO component.

The step 2-2 includes a step 2-2a of compressing and dewatering the pumice pulverized material with reduced crystallization inhibiting substances to form a cake, and a step of pulverizing the pumice pulverized in a cake state into a pulverizer 2-2b process can be further performed.

In the step 2-1, the step 2-1a is carried out in which the ground pumice is immersed in hot water at 50 to 80 DEG C for 0.5 to 2 hours and stirred to lower the CaO content of the ground pumice to 0.5 to 5 wt% .

In the step 2-1, high-pressure air is injected into the water tank through a plurality of fine holes formed on the inner surface of the water tank to generate a large number of small air bubbles, , And the rising stream may be further mixed with the swirling flow of the agitator to generate mixed turbulence.

In the step 2-1, the CaO content is measured during the 2-1a step or the 2-1b step, and when the measured value is compared with the CaO content set value, In the step 2-1a, the process is switched to the 2-1b step and then is discharged. In the 2-1b step, the second-1a step is performed again, and then the CaO content is measured to be discharged. 2-1c step can be further performed.

In the fifth step, the alkaline substance selected from sodium hydroxide (NaOH) and sodium carbonate (Na ₂ CO ₃ ) is used as an alkaline substance and the powdery alkaline substance selected for 100 parts by weight of the pulverized powdery pumice- And the mixture is heat-treated at 500 to 900 ° C for 0.5 to 3 hours to fuse the pumice powder and the alkali substance.

In the sixth step, 200 to 1000 parts by weight of water, 5 to 25 parts by weight of an aluminum source and 0.5 to 5 parts by weight of a zeolite seed may be mixed with 100 parts by weight of the pumice fused product produced in the fifth step. The aluminum source may be NaAlO ₂ .

The seventh step may be carried out at a temperature of 20 to 60 DEG C for 3 to 12 hours.

In the eighth step, crystallization may be performed for 2 to 72 hours in a batch reactor at 80 to 100 ° C and atmospheric pressure.

The synthetic zeolite production method of the present invention by the above-

Synthesized zeolite is produced by using the pumped waste, and crushed pumice powder and alkali material are mixed, stirred, and fused at a high temperature, mixed as uniformly as possible, and then reacted with an aluminum-containing material to crystallize to obtain a purity of at least 80 wt% Zeolite < / RTI > Particularly, it is possible to improve the purity of zeolite by making it possible to produce various types of zeolite by reducing the content of CaO to 5 wt% or less from the pumice having a large amount of CaO component and performing the zeolite synthesis reaction.

In addition, since hydrothermal reaction does not occur, it can be produced in a batch type reactor under atmospheric pressure. Therefore, it is possible to mass-produce by continuous process, thereby reducing production cost and preventing environmental pollution caused by leachate and fine dust scattering It is now possible to provide a useful method to do so.

1 is a flow chart of a manufacturing process according to an embodiment of the present invention;
2 is a flow chart of a manufacturing process according to another embodiment of the present invention.
3 is an analysis diagram of zeolite 4A prepared by the process of the present invention.
4 is a SEM photograph of the zeolite 4A produced by the production method of the present invention.
Fig. 5 is a graph showing the relationship between the zeolite prepared by the production method of the present invention

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the accompanying drawings. It should be understood, however, that the appended drawings illustrate only the contents and scope of technology of the present invention, and the technical scope of the present invention is not limited thereto. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the technical idea of the present invention based on these examples.

1 and 2 are flowcharts of manufacturing processes according to a preferred embodiment of the present invention.

The method for producing synthetic zeolite using pumice according to the present invention comprises the steps of: a first step of a pulverization step; a second step of removing a crystallization inhibiting substance; a third step of a heat treatment step; a fourth step of a mixed powder stirring step; 5 process, a sixth process as a mixing process, a seventh process as an aging process, an eighth process as a crystallization process, and a ninth process as a commercialization process.

The first step is a step of pulverizing pumice, and pumice, which is a variety of minerals, can be pulverized and used. Preferably, the pumice is a pumice stone which is selected and discarded in a coal mine area, which is a pumice stone, which is subjected to a munition process in a coal mine area, and which is free of coal components generated during a mine excavation process. And grinding it.

In this first step, it is preferable to crush into the form of powder as much as possible because charcoal or pumice in the rock-like pumice may remain charcoal or impurities. The crushing can be performed using a continuous crusher (hammer crusher or scutter crusher) which can be continuously supplied by a conveyor belt. At this time, the degree of pulverization is reduced to 30 mesh or less, preferably 30 to 60 mesh.

Next, referring to FIG. 2, a second step of removing the CaO component, which is a crystallization inhibiting substance, is performed.

The second step is a step of removing the CaO component which is an obstruction to the crystallization of the zeolite. The step 2-1 may be divided into a second step of removing the CaO component and a second step of removing the CaO component. Step 2-1 is a step of 2-1a which is a hot water agitation step, step 2-1b which is an air injection mixing step of injecting air injection to generate mixed turbulence, and step 2-1c of measuring CaO content And the second-2 process as the dewatering process may be subdivided into the second-2-a process of forming a cake and the second-2b process of pulverizing the cake.

In the step 2-1, the content of CaO is reduced to 5 wt% or less, preferably 3 wt% or less, so that the zeolite crystallization rate can be increased and various types of zeolite can be synthesized. It is preferable to remove the CaO component as much as possible to improve the reactivity. However, considering the economical efficiency, it is preferable to decrease the content to 1 to 3 wt% based on the weight of the pumice pulverized product, and then perform the subsequent reaction step. Particularly, when continuous zeolite synthesis is carried out using pumice having a high content of CaO component, the content of CaO should be lowered through the second step before crystallization.

In the step 2-1a of the step 2-1, the pumice pulverized product is immersed in a water bath containing hot water at 50 to 80 ° C for 0.5 to 2 hours so that the CaO component can be easily eluted from the pumice ground product, So that the CaO content can be finally reduced to at least 5 wt%, preferably to less than 3 wt%.

The pumice pulverized product can be made to elute the CaO component by various methods. For example, a batch system in which the water is poured into a water tank and agitated, a conveyor system that is placed on a conveyor belt and passes through a water tank, a horizontal water tank rotation system in which a spiral vane is formed on the inner surface of the horizontal water tank, And a method in which a plurality of units are connected in parallel for continuous discharge can be applied.

Step 2-1b of the second step is an air injection mixing step for generating mixed turbulence. For example, a large number of fine holes are formed on the inner surface of a water tank and a large number of small air bubbles are generated in the water tank by injecting high pressure air into the water tank. The upward flow generated by the rising air bubbles and the swirling flow by the stirrer, (Ca (OH) ₂ ) and the surface of the pumice powder containing calcium oxide (CaO) by increasing the frequency of contact between water and CaO, The frequency of elution can be increased. In addition, since the small air bubbles rise while passing through the pumice pulverized product, the pumice pulverized product is mixed up or down to increase the contact frequency with water, so that the CaO can be easily eluted. At this time, various kinds of gas such as hydrogen carbon dioxide can be injected in addition to air.

The 2-1a step and the 2-1b step may be sequentially performed, or any one of them may be selectively performed.

In addition, the 2-1a step and the 2-1b step can be selectively performed according to the CaO content of the pumice pulverized product through the 2-1c step of measuring CaO content.

For example, if the CaO content of the pumice pulverized product subjected to the second-1a process is measured through the second-1c process, the second-1a process is performed when the measured CaO content is higher than the target content, The CaO content is measured periodically. When the CaO content is higher than the target content, the time required to pass through the tank is increased, so that the CaO content at the discharge side can be controlled to be lower than the target content.

In addition, when the CaO content measured from the pumice pulverized material subjected to the 2-1a process is higher than the target content through the measurement of the CaO content, the 2-1b process is performed, and the stirring method and the air injection method are mixed The CaO content can be reduced. Also in the pumice crushing performed in the step 2-1b, the CaO content is measured through the CaO content measuring process, and if the CaO content is higher than the target content, the 2-1a process or the 2-1b process is performed again .

The CaO content in the second-1c step may be continuously measured continuously or may be measured at certain time intervals to control the apparatus speed. If the CaO content measurement process is further performed, the CaO content of the pumice pulverized by the automatic control of the present process can be lowered to a certain level or less even if the CaO content of the input raw material is changed. Therefore, the quality of the final produced zeolite is kept constant And provides an effect that can be achieved. In the CaO content measuring process, the CaO content is preferably set to 5% by weight or less, more preferably 3% by weight or less based on the total amount of the mixture, and the degree of crystallization is improved.

In addition, in the step of removing the CaO component, any one of the steps 2-1a and 2-1b is completed and an additional step is performed depending on the content of CaO. In addition, in the step 2-1a, The CaO content is measured periodically in the course of performing the stirring process, and if the measured CaO content value is out of the range of 1 wt% with respect to the set CaO content value, the CaO removal rate per hour can be increased by performing the 2-1b process.

For example, if the 2-1 step of removing the CaO component is performed for 1 hour, the CaO content is removed by the water tank stirring method of the step 2-1a, and the CaO content is measured at the time when 30 minutes have elapsed. If a difference of 1% by weight or more relative to the set value occurs, pneumatic pulverization with a CaO content or less set within the set time can be provided by injecting air to perform the second-1b step.

Here, the determination of the conversion to the 2-1b process during the 2-1a process is made by the difference between the CaO content set value and the CaO content measured value, and the error range from the CaO content set value is set to the remaining time And can be converted into data by automatic conversion according to the result of CaO content measurement.

That is, in the CaO content measuring step (step 2-1c), when the remaining time for performing the CaO component removing step (step 2-1) is 30 minutes, the error range between the set value and the measured value is set to 1 wt% In the case of 15 minutes, the error range between the set value and the measured value is converted into data of 0.4 wt%, and it is determined whether the CaO content measurement value measured at each time point is within the error range to continue the second- Whether the CaO component is removed promptly or the like can be automatically set.

If the automatic operation setting is included in this manner, the zeolite produced even when pumice with various CaO contents is introduced can be produced by a similar degree of crystallization, and productivity can be maintained uniformly.

On the other hand, in the batch method and the horizontal water tank rotation method, vibration or microwave is added to the water tank tanker to increase the contact frequency between water having a low concentration of calcium hydroxide (Ca (OH) ₂ ) and pumice powder in the water tank, .

Next, the second step 2-2, which is a dehydration step, is a step of dehydrating the pumice pulverized material subjected to the second step of the CaO component removing step, and centrifugal force or pressure method may be applied.

The second step 2-2 includes a second step 2a-2c for compressing and dewatering the pumice pulverized material having reduced crystallization inhibiting substances to form a cake, and then the second-2b step of crushing the cake is carried out.

As an example of caking in the step 2-2a, dewatering can be performed by pressurization using a continuous filter press.

Step 2-2b is a step of crushing the pressed cake. The step 2-2b is a step of crushing the crushed pumice crushed into a cake by crushing the crushed pumice into a stirrer including a crusher. At this time, heat is applied in the crushing process so that drying is performed simultaneously, thereby making the powder dry. In the stirrer, a heating jacket is constituted so as to crush the pumice pulverized by heat supply, and at the same time, water is evaporated to make the pulverization of the powder state, or the pumice pulverized by the pulverizing roll which generates heat is pulverized Can be performed simultaneously. In the step 2-2b, only the cake crushing step is performed, and the drying by heat may be performed together with the combustion in the following heat treatment step.

Next, a heat treatment process which is the third process is performed. The third step is a step of charging the pumice form powder discharged from the second step into a heat treatment tank using a transferring means to dry by evaporation of water, and calcining carbon and other combustible impurities remaining in the pumice powder. The conveying means may be conveyed by various known methods such as a conveyor belt or a dropping method. The heat treatment temperature in the third step is in the range of 700 to 800 ° C.

At this time, the heat treatment tank (baking furnace) may be heated while the pumice pulverized material is moved by the conveyor belt, or may be put into a batch type baking furnace so that the heat treatment is performed. In this case, the heat treatment temperature is in the range of 700 to 900 ° C. When the temperature is less than 700 ° C, the combustion residue of charcoal or other impurities remaining in the pumice powder is not completely removed, In case of heating at a temperature higher than 900 ° C, the effect of heat treatment due to temperature rise is insufficient, but energy consumption is increased, so that heat treatment is preferably performed in the above range.

The pumice-milled product is preheated at a low temperature of 100 to 300 ° C for 10 to 15 minutes, and then calcined at a high temperature, so that the calcined product is sufficiently dried, followed by calcination, Efficient impurity removal can be achieved while shortening the time. That is, a calcination time of 70 to 100 minutes is required when there is no low temperature preheating, but a calcination time of 50 to 60 minutes is required when low temperature preheating is performed, so it is preferable to perform low temperature preheating at the total energy efficiency.

The fourth step of stirring the mixed powder is a step of mixing the hard-pulverized product heat-treated in the third step with an alkaline substance in powder form and stirring.

The mixed alkali material may be selected from sodium hydroxide (NaOH) and sodium carbonate (Na ₂ CO ₃ ). An alkali substance containing a sodium component; Potassium hydroxide, calcium carbonate, potassium hydroxide, calcium hydroxide, and barium hydroxide, and an alkali substance containing potassium and calcium or barium.

It is also preferable that such alkali materials are pulverized to 30 to 60 mesh like pumice powder to be mixed in a powder state in a powder state to enable uniform mixing.

As the mixing ratio, it is preferable that 50 to 200 parts by weight of the powdery alkali material is mixed with 100 parts by weight of pulverized pumice powder. When the alkaline material is mixed in an amount of 50 parts by weight or less, the formation of an aluminate ion source and a silicate ion source is insufficient and the crystallization is low. When the alkaline material is mixed in an amount of 200 parts by weight or more, It is preferable to mix them within the above range because the degree of formation enhancement is insufficient.

As a mixer used for the mixing, it is preferable to uniformly mix the mixture using a ribbon mixer. For the continuous process, a CSTR method can be applied. For example, a plurality of ribbon mixers are installed in series, So that continuous mixing can be performed. The stirring time of the mixed powder stirring step is 5 minutes to 60 minutes, preferably 10 to 20 minutes so that the pumice pulverized material and the alkaline material can be mixed sufficiently homogeneously.

In the fusing step, which is the fifth step, the uniformly stirred mixed powder is charged into a heating bath and heated to fuse the alkali substance and the pumice powder. In the fifth step, the alkali material in the mixed powder is melted and fused with the pumice powder by the supplied heat. Accordingly, when the alkali substance and the pumice powder are uniformly mixed in powder form, the molten alkali substance and the pumice powder are fused at a ratio of 1: 1, thereby forming a structure favorable for zeolite synthesis.

That is, by heating, SiO ₂ in the main component of pumice turns into Na ₂ SiO ₃ soluble in water or NaAlSiO ₄ dissolving in alkaline aqueous solution and forms aluminate ion source and silicate ion source necessary for zeolite synthesis.

It is preferable that the heat treatment temperature in the fusion step is 500 to 900 占 폚 for 30 to 180 minutes. That is, when the temperature is lower than 500 ° C, the alkali material is not well dissolved and is not well fused with the pumice powder. When the temperature is higher than 900 ° C., the alkali material is excessively melted to be solidified with the adjacent alkali materials, It is preferable to apply heat.

When sodium hydroxide (NaOH) is used as the alkali substance, it is preferable to mix 100 to 120 parts by weight with respect to 100 parts by weight of the pumice pulverized product, and to perform fusion at a temperature of 500 to 550 ° C in the fusion step.

When sodium carbonate (Na ₂ CO ₃ ) is used as the alkali substance, it is preferable to mix 50 to 200 parts by weight with respect to 100 parts by weight of the pumice milled material, and to effect fusion at a temperature of 800 to 900 ° C in the fusion step Do. When sodium carbonate is used and heat is applied at a temperature of 600 ° C or below to cause fusion, 50% or more of the quartz or aluminum silicate contained in the pumice powder is remained and the yield is lowered because it is not involved in crystallization into zeolite. Therefore, it is preferable to control the heat treatment temperature according to the alkali substance to be changed into an amorphous or water-soluble form which is easy to use as a zeolite raw material.

Next, the sixth step of the mixing process is performed. The sixth step is a step of mixing the pumice fused product of the pumice pulverized product and the alkali substance, the water, the aluminum source and the zeolite seed, which have been subjected to the fusion process in the fifth step.

As the mixing ratio, 200 to 1000 parts by weight of water, 5 to 25 parts by weight of an aluminum source and 0.5 to 5 parts by weight of a zeolite seed are mixed with 100 parts by weight of the pumice fusion product produced in the fusion process.

When the water is mixed in an amount of 200 parts by weight or less, the amount of the zeolite to be added is lowered. When the water is mixed in an amount of 1000 parts by weight or more, the crystallization rate is slowed, , And more preferably 400 to 500 parts by weight. Also, by adjusting the mixing amount of the water, the concentration of alkali in the mixture can be increased to produce NaP1 type zeolite having a stable structure, or sodalite can be produced.

In addition, the aluminum source is added to control SiO ₂ / Al ₂ O _3, which is the composition ratio of the finally required synthetic zeolite. As the aluminum source, an aluminum-based waste coagulant (Al content: 5 to 40 wt%) is used, and NaAlO ₂ is typically used.

In addition, the zeolite seed serves to determine the shape of the finally produced synthetic zeolite. In particular, since the purity is high in the present invention, a circulation process may be further included in the process so that some of the produced zeolite can be reused as a seed.

In order to perform the mixing process of the sixth step, a plurality of synthesis reactors for containing the respective mixtures are formed, and the synthesis reactors are installed in series to allow the synthesis reactors to be sequentially passed through the mixer, , And each of them reacts independently, and then sequential discharge is performed.

The seventh step is a step of aging the mixture of the sixth step while stirring at a low temperature of 20 to 60 캜.

This step is a step of stirring the mixture so that the pumice fusion can sufficiently dissolve in water, and stirring is preferably performed for 3 to 12 hours. When the aging time is less than 3 hours, the pesticide is not sufficiently dissolved in water, and the amount synthesized in the crystallization step is lowered. When the aging time exceeds 12 hours, the degree of crystallization is insufficient. .

In the eighth step, the mixture aged through the seventh step is heated to a heating temperature of 80 to 100 ° C to synthesize and grow zeolite crystals.

The eighth step in which the present crystallization is carried out can be carried out in a hydrothermal reactor, but it can also be carried out in a general batch reactor. Therefore, it is possible to produce a zeolite crystallized in a similar manner to the continuous process by installing a plurality of batch reactors in parallel and successively performing a crystallization reaction by a time difference to perform sequential discharge.

The eighth step is performed for 2 to 72 hours to allow crystallization to proceed. Preferably, the crystallization proceeds in the reaction vessel for 3 hours or more. The duration of performing the crystallization according to the type of zeolite can be controlled within the range have.

In the ninth step, the zeolite synthesized through crystallization in the eighth step is filtered, washed, and dried to produce a commercial product.

That is, the zeolite crystallized in the eighth process is filtered and washed with distilled water to remove the mother liquor and metal ions attached to the zeolite, and dehydration is performed through a continuous filter press. In addition, the wastewater generated in the dehydration process can be used in place of water to be mixed with the pumice fusion in the mixing step.

The drying is performed at a temperature in the range of 90 to 100 ° C, and continuous drying can be performed through continuous tunnel drying.

The dried zeolite may be used in the form of powder, further calcined, or in the form of pellets or beads, and then calcined at a high temperature.

Hereinafter, the present invention will be described in more detail with reference to examples.

1. Preparation of zeolite of the present invention

- pumice receiving and crushing process (first process)

We received pumped stones near the coal mine in Gangwon Province.

The received pumice was pulverized to 30 mesh (about 600 mu m) or less through a crusher.

The pulverized pumice pulverized material was analyzed by XRF and the results are shown in Table 1 below.

[Table 1]

Referring to Table 1, it can be seen that the CaO content is about 8 wt%. Also, since the sum of SiO ₂ and Al ₂ O ₃ is about 81%, the purity of zeolite synthesis is also expected to be more than 81%.

- CaO removal process (second process)

The ground pellet was charged into hot water at 90 ° C in a batch water bath and stirred for 1 hour to lower the CaO content to 7 wt% or less based on the total weight.

The pumice pulverized with lower CaO content was dehydrated by compression method, and the crushed cake was crushed and supplied to the heat treatment process.

- Heat treatment process (third process)

The pumice pulverized by the CaO removal process was put into a firing furnace and heat treated at 800 ° C. At this time, the heating was performed at 200 ° C for 10 minutes, then heated, and then heat-treated at 800 ° C for 50 minutes.

When the preheating process is performed, as in the case of the heat treatment at 800 ° C for 100 minutes without preheating, the residual combustion and the combustion of the volatile substances are completed. As a result, the heating time can be shortened. Therefore, in the present invention, heat treatment is performed by a method including a preheating process for shortening the time.

- Mixed Powder Agitation Process and Fusion Process (Fourth and Fifth Process)

100 g of the heat treated pumice pulverized product was taken into a mixer, 120 g of powdery sodium hydroxide was selected as an alkaline substance, 120 g of the powder was added to a mixer, stirred for 10 minutes, and mixed uniformly to prepare a mixed powder.

The mixed powder of the pumice ground powder and sodium hydroxide was put into a heating tank and heated at 500 DEG C for about 1 hour to be fused.

- mixing process, aging process and crystallization process (sixth process, seventh process and eighth process)

100 g of the fused pesticide fusion, 500 mL of water, and 1 g of the zeolite 4A seed were added to the synthesis reaction tank.

In addition, since the molar ratio of SiO ₂ / Al ₂ O ₃ in pumice is 2.9, 20 g of NaAlO ₂ selected as an aluminum source was further added to adjust the molar ratio of SiO ₂ / Al ₂ O ₃ to 2.0.

The mixture was aged at a low temperature of 30 캜 for 5 hours with stirring, and the pesticide was sufficiently dissolved in water.

The heating temperature of the aged mixture was raised to 90 캜 and stirred for 5 hours to proceed crystallization.

- Zeolite commercialization process (ninth process)

The crystallized zeolite was filtered and washed with distilled water, dehydrated and dried at 100 ° C. in a drying oven to produce powdered zeolite 4A.

2. Preparation of zeolite 4A

1) Example 1 - Preparation of zeolite 4A by the above - mentioned production method, but the CaO component content to the total weight of the pumice pulverized product was adjusted to 7 wt% or less by changing the process execution time in the CaO removal process.

2) Example 2 - Preparation of zeolite 4A by the above - mentioned production method, CaO content was adjusted to 6 wt% or less with respect to the total weight of the pumice pulverized product in the CaO removal process.

3) Example 3 - Preparation of zeolite 4A by the above - mentioned preparation method, but CaO content was adjusted to 5 wt% or less with respect to the total weight of the pumice pulverized product in the CaO removal process.

4) Example 4 - The zeolite 4A was prepared by the above - mentioned preparation method, and the content of CaO in the CaO removal process was adjusted to 4 wt% or less with respect to the total weight of the pumice pulverized product.

5) Example 5 - Preparation of zeolite 4A by the above - mentioned preparation method, but CaO content was adjusted to 3 wt% or less with respect to the total weight of the pumice pulverized product in the CaO removal process.

6) Example 6 - The zeolite 4A was prepared by the above - mentioned preparation method, but the content of CaO in the CaO removal process was adjusted to 2 wt% or less based on the total weight of the pumice pulverized product.

7) Example 7 - Preparation of zeolite 4A by the above - mentioned preparation method, but CaO content was adjusted to 1 wt% or less with respect to the total weight of the pumice pulverized product in the CaO removal process.

8) Example 8 - Zeolite 4A was prepared by the above - mentioned preparation method, and CaO content was adjusted to 0.5 wt% or less with respect to the total weight of the pumice pulverized product in the CaO removal process.

9) Comparative Example 1 - The zeolite 4A was prepared by the above production method, but the CaO removal process was not carried out.

Experimental Example 1) Measurement of crystallinity

XRD was measured using the zeolite produced in Examples 1 to 8 and Comparative Example 1 to calculate the degree of crystallization.

[Equation 1]

(Wherein the product is the zeolite prepared in Examples 1 to 6, the reference product is commercial zeolite 4A from Wako or commercial zeolite NaP1.

The chemical composition of the commercial zeolite 4A was 47.32 wt% SiO _2, 34.87 wt% Al ₂ O ₃ , 17.66 wt% Na ₂ O, 0.07 wt% CaO, 0.03 wt% SO _3, 0.03 wt% Fe ₂ O ₃ , 0.02% by weight.

The crystallinity is a relative value when the crystallinity of the reference material is 100%.)

The CaO content and the crystallization degree of the zeolite prepared by using the CaO component with respect to the total weight of the pumice prior to the heat treatment in Examples 1 to Comparative Example 1 are summarized in Table 2 below.

[Table 2]

As shown in Table 2, Examples 1 to 8 showed higher crystallinity than Comparative Example 1, but Examples 1 and 2 were almost similar to each other. The degree of crystallization was remarkably improved in Example 3 in which the CaO component was adjusted to 5 wt% or less, and in Example 5 in which the CaO component was adjusted to 3 wt% or less.

However, in order to lower the content of CaO to 0.5% by weight or less based on the total weight as in Example 8, the stirring time in the water tank was doubled as compared with Example 5. That is, in order to numerically obtain the improvement of crystallinity, the CaO content in the CaO component removing step is set to 0.5 to 5 wt% based on the total weight, preferably, the CaO content is set to 1 to 3 wt% , And most preferably, the CaO content is set to 3% by weight and the operation is performed to obtain a high degree of crystallinity with respect to time, thereby improving the productivity.

3 is an analysis chart for zeolite 4A (Example 5; Zeolite AG) and Zeolite A-ref. Prepared using pumice according to the production method of the present invention, 5 is an SEM photograph of the zeolite 4A produced by the method of the present invention. As described above, it can be seen that the synthetic zeolite prepared by the production method of the present invention has a peak close to that of the commercial zeolite.

Experimental Example 2 Measurement of CaO content after CaO removal process

1 kg of the pumice pulverized product having the content shown in Table 1 was put into a batch water tank storing 30 L of hot water to perform CaO removal process.

The batch type water tank has a structure in which a plurality of air injection hoses are communicated with each other and a high pressure air is supplied in a small droplet form through the inner side surface and the lower surface, and an agitation method by an agitator and an air injection method . &Lt; / RTI >

10) Example 9 -A stirrer agitation method was performed for 30 minutes, and then agitator stirring method was further performed for 30 minutes, and the CaO content was measured after completion.

11) Example 10-The air suspension method was run for 30 minutes, the air injection method was further performed for 30 minutes, and the CaO content was measured after completion.

12) Example 11 -A stirrer agitation method was carried out for 30 minutes, then the air injection method was carried out for 30 minutes, and the CaO content was measured after completion.

13) Example 12 -A stirrer agitation method was carried out for 30 minutes, then agitator stirring method and air injection method were further performed for 30 minutes, and the CaO content was measured after completion.

The CaO contents measured by the above Examples 9 to 12 are shown in Table 3 below.

[Table 3]

As shown in Table 3 above, when the CaO removal process is performed at the same time, it can be understood that the stirring method is more effective in reducing the CaO content than the air injection method. This is because, when a large number of air injection holes are formed, pneumatic pulverized material may flow into the air injection hole when the air injection is not performed, and the air hole may be clogged, resulting in a limited number of air injection holes. .

It can be seen from the effect of the CaO content that a high removal rate is obtained when the stirring method and the air injection method of Example 12 are partially mixed, and Example 9, which is performed only by the stirring method, shows a high removal rate. However, it was found that the reduction of the CaO content was relatively low in Example 10 and Example 11 which were carried out by air injection alone.

Therefore, in the CaO removal step, the mixing method of the stirring and the air injection of the twelfth embodiment can be applied to shorten the CaO removal process time. However, it is desirable to reduce the CaO content within a short time to a desired target value by applying an air injection method to increase the energy consumption, so that it is applied when the gap is large as compared with the target CaO content value.

3. Preparation of zeolite NaP1 by the process of the present invention

15) Example 13 - Zeolite NaP1 was prepared by the production method of the present invention.

In the second step (CaO removal process), the content of CaO component with respect to the total weight of the pumice pulverized product was adjusted to 7 wt% or less.

Sodium carbonate was selected as the alkali substance to be added in the fourth step (mixed powder stirring step).

In the fifth step (fusing step), the mixed powder of pumice ground powder and sodium carbonate was put into a heating tank and fused by heating at 850 ° C for about 2 hours.

100 g of the pesticide fused in the sixth step, 500 mL of water, and 1 g of the zeolite NaP1 seed were added to the synthesis reaction tank.

At this time, since the molar ratio of SiO ₂ / Al ₂ O ₃ is 2.9, it is the same as 2.9, which is a molar ratio condition of zeolite NaP 1, so NaAlO ₂ selected as an aluminum source is not added separately.

In the eighth step (crystallization step), crystallization proceeded at 90 DEG C for 18 hours with stirring.

The crystallized zeolite was filtered and washed with distilled water, dehydrated and dried at 100 ° C in a drying oven to produce powdered zeolite NaP1.

16) Examples 14 to 20 - The same procedure as in Example 13 was carried out except that in the second step (CaO removal step), the content of CaO was 6, 5, 4, 3, 2, 1, 0.5% by weight or less.

17) Comparative Example 2 - The same procedure as in Example 13 was carried out except that the second step (CaO removal step) was not carried out and the content of CaO component with respect to the total weight of the pumice pulverized product was about 8% by weight as shown in Table 1 .

In Examples 13 to 20 and Comparative Example 2, the molar ratio of SiO ₂ / Al ₂ O ₃ was adjusted to 2.9 by using NaAlO ₂ selected as the aluminum source in the sixth step.

Experimental Example 3 Measurement of crystallinity of zeolite NaP1

The crystallization degree was calculated by applying Equation (1) of Experimental Example 1. The reference product here is commercial zeolite NaP1 from Wako.

The measured bonding degrees are shown in Table 4 below.

[Table 4]

As shown in Table 4, it can be seen that the zeolite NaP1 has a higher degree of crystallization from Example 15 in which the content of CaO in the pumice pulverized product is reduced to 5% by weight or less like zeolite 4A, and is suitable for commercialization in Example 17 having 3% It is understood that a degree of crystallization of 80 wt% or more appears.

Further, it can be seen that the crystallization degree is further increased when the CaO content in the ground pellet is lowered. However, as in the case of producing zeolite 4A, it takes a long time to perform the second step (CaO component removal step) , It is preferable to carry out the zeolite production process by setting it to the level of 3% by weight.

The analysis of the zeolite NaP1 produced by the method of Example 17 is shown in FIG.

Claims

A first step of pulverizing the selected pumice into a powder having a size of 30mesh or less using a continuous crusher; A step 2-1 of pouring the pumice pulverized product of the first step into a water tank to elute and remove the CaO component which is a crystallization inhibiting substance and a step 2-2 of dehydrating the pumice- 2 steps; A third step of introducing the pumice pulverized material having a reduced CaO component into the heat treatment tank in the second step so as to heat and remove carbon and other impurities remaining in the pumice pulverized product; A fourth step of putting the pumice powder and the powdery alkali substance heat-treated in the third step into a stirrer and uniformly stirring the charged mixed powder; A fifth step in which the mixed powder uniformly stirred through the fourth step is introduced into a heating tank to be heated and fused with the pumice pulverized by heat; A sixth step of mixing water, an aluminum source and a zeolite seed with a fusion product obtained by performing the fusion step in the fifth step; A seventh step of aging the mixture of the sixth step while heating at 20 to 60 캜 at a low temperature while stirring; Elevating the heating temperature of the aged mixture in the seventh step to 80 to 100 占 폚 to crystallize the zeolite crystals so as to effect crystallization; And a ninth step of filtering, washing and drying the zeolite synthesized in the eighth step to produce a product,
In the second step of the second step,
A step 2-1a in which the ground pumice is immersed in hot water at 50 to 80 캜 for 0.5 to 2 hours and stirred to lower the CaO content of the ground pumice to 0.5 to 5% by weight;
Pressure air is injected into the water tank through a plurality of micro-holes formed on the inner surface of the water tank to generate a large number of small air bubbles in the water tank, and an upward flow is formed while the generated air bubbles rise, and the upward flow is mixed with the swirling flow of the stirrer A 2-1b step of generating mixed turbulence;
The CaO content is measured during the 2-1a process or the 2-1b process, and when the measured value is compared with the CaO content set value, if it exceeds the allowable error range according to the remaining process execution time, And a second-1c step of performing a second conversion step of performing the second-1b process and then discharging the second-first-step content, Wherein the zeolite is a zeolite.

The method according to claim 1,
Wherein the pumice is a closed stone stone discarded in an abandoned mine.

delete

The method according to claim 1,
In the second step
And removing the CaO component so that the CaO component is included in the range of 1 to 3% by weight based on the weight of the whole pumice pulverized product.

delete

The method according to claim 1,
In the step 2-2,
A step 2-2a of caking the pumice pulverized material with reduced crystallization inhibitor by squeezing and dewatering;
And a second step (2b) of pouring pumice pulverized in a cake state into a stirrer and crushing the pulverized powder in a powder state.

The method according to claim 1,
In the fifth step,
As an alkali substance, sodium hydroxide (NaOH) and sodium carbonate (Na ₂ CO ₃ ) are selected and used,
The powdery alkali substance is mixed in an amount of 50 to 200 parts by weight based on 100 parts by weight of the pulverized powdery pearl milled product,
Treated at 500 to 900 DEG C for 0.5 to 3 hours to fuse the pumice powder and the alkali substance.

The method according to claim 1,
In the sixth step,
Wherein water is mixed with 200 to 1000 parts by weight of water, 5 to 25 parts by weight of an aluminum source and 0.5 to 5 parts by weight of a zeolite seed, based on 100 parts by weight of the pumice fused product produced in the fifth step.

12. The method of claim 11,
Lt; _{RTI ID =} 0.0 > NaAlO2. &Lt; / _RTI >

The method according to claim 1,
In the seventh step,
And stirring the mixture at a temperature of 20 to 60 DEG C for 3 to 12 hours.

The method according to claim 1,
In the eighth step,
Wherein the crystallization is carried out for 2 to 72 hours in a batch reactor at 80 to 100 ° C and atmospheric pressure.