WO2017078308A1

WO2017078308A1 - Method for preparing synthetic zeolite using bottom ash in thermoelectric power plant

Info

Publication number: WO2017078308A1
Application number: PCT/KR2016/011864
Authority: WO
Inventors: 이경우; 정유식; 신희용
Original assignee: 주식회사 지엔티엔에스
Priority date: 2015-11-05
Filing date: 2016-10-21
Publication date: 2017-05-11
Also published as: KR101602933B1

Abstract

The present invention relates to a method for preparing synthetic zeolite using bottom ash in a thermoelectric power plant and, more specifically, to a method for preparing synthetic zeolite wherein zeolite is produced by pulverizing bottom ash as a coal waste in a thermoelectric power plant, mixing the bottom ash pulverized material and an alkaline material each in a powder form, homogeneously fusing the mixture through an application of heat, mixing the fused material in a powder form together with an aluminum-containing material and zeolite seeds in water, followed by aging, crystallization, and drying, and here, the bottom ash pulverized material is mixed with the alkaline material to attain crystallization after the content of CaO as a crystallization inhibitor is reduced to a certain level or less, thereby improving the degree of crystallization to allow mass production and maintaining the quality of zeolite at a predetermined level.

Description

Manufacturing method of synthetic zeolite using flooring material of thermal power plant

The present invention relates to a method for producing a synthetic zeolite using a bottom ash of a thermal power plant, and more particularly, to crush the bottom ash (bottom ash), which is coal waste of a thermal power plant, and to mix the bottom ash pulverized and alkaline materials in powder form, The fused powdery fusion is mixed with water together with the aluminum-containing material and zeolite seed, and produced by zeolite through aging, crystallization and drying process, wherein the ground ash is crushed. The present invention relates to a method for producing a synthetic zeolite that can reduce the CaO content to a certain level and then mix with an alkali material to make crystallization, thereby improving the crystallinity and allowing mass production and maintaining the quality of the zeolite at a certain level.

At present, a large part of Korea's electricity supply depends on thermal power generation. Coal, a raw material for thermal power generation, contains a considerable amount of inorganic components, and oxides remain after combustion, especially coal ash containing a large amount of silica and alumina.

The coal ash is divided into fly ash and bottom ash, and the fly ash is light in powder form, and thus is widely used as various industrial raw materials such as cement, building materials, cosmetics, zeolite synthesis, and so on. However, since the flooring material has almost no recycling field, the landfill is buried as industrial waste and the landfill is difficult due to recent environmental regulations.

As a field utilizing coal ash, a technique for synthesizing zeolite using coal ash has been variously presented in Korea, but most of them suggest only a zeolite synthesis technique using fly ash. In addition, the coal ash produced in the thermal power plant is basically high in CaO content due to the limestone input from the desulfurization process, particularly in the case of fly ash to 20 wt.% Or more. When such CaO component is high, it is difficult to manufacture a zeolite of desired property because zeolite synthesis | combination and purity, receiving amount, crystallinity are low.

In addition, it is difficult to manufacture a large amount of the zeolite of the required type by the hydrothermal synthesis method, which is most commonly used as a conventional zeolite synthesis technology, and the method of dissolving molten fly ash in water and then extracting only pure substances by centrifugation. The production yield is low because it is synthesized by the extraction of zeolite, it is difficult to synthesize a variety of zeolite type without extracting the pure substance, it was difficult to mass production for industrial use.

In addition, the hydrothermal synthesis method of the existing method is difficult to mass production because it is made under high pressure conditions, the method of using the alkaline solution of the existing method has a problem in the equipment corrosion.

In addition, fly ash or bottom ash is burned and received by the coal having a variety of components in each region, so the zeolite produced therefrom is difficult to produce in a certain quality or quantity, a situation that requires a study on a new method of manufacturing.

Korean Patent Registration No. 10-1138854 (2012.05.16.Registration; Prior Art 1) proposed a synthetic zeolite synthesized from waste containing silica and alumina. Prior Art 1 is to prepare a synthetic zeolite by mixing the fly ash with an alkali material and fusion, mixing water and aluminum-containing material and zeolite seed, and then aged and crystallized. However, Prior Art 1 has a disadvantage in that the crystallinity of zeolites having pores of large size such as zeolite X type and Y type, in addition to zeolite A type, is mixed because a large amount of CaO component which is a crystallization hindering material is mixed.

Korean Patent No. 10-0656177 (registered Dec. 5, 2006; Prior Art 2) suggested a method for synthesizing NaP1 zeolite using a thermal power plant flooring material. Prior art document 2 is a flooring material pre-treatment step of pulverizing the flooring stacked on the boiler floor for thermal power plants at 90 ~ 110 ℃ 22 ~ 26 hours, the ground flooring to a particle size of less than 100㎛; Mixing the pretreated flooring material with NaOH solution of 2M ~ 3M to synthesize zeolite by normal temperature or atmospheric pressure or hydrothermal synthesis at 80 ℃ ~ 100 ℃; In addition, the synthesized zeolite is washed with distilled water and then dried at 70-90 ° C. for 11-13 hours. Since the prior document 2 synthesizes the zeolite by the hydrothermal synthesis method, it is not suitable for mass production because the high temperature and high pressure conditions should be made. In addition, although the content of CaO component, which is a crystallization hindering material rather than fly ash, is still higher than 9% by weight relative to the total weight, it is difficult to produce various types of zeolites by the crystallization hindering material at normal temperature and pressure.

The synthetic zeolite production method using the flooring of the present invention,

Synthetic zeolites with high added value are manufactured by using low-recyclability flooring materials, but various types of zeolites are used in high-pressure hydrothermal reactors as well as normal-pressure batch reactors by lowering the content of CaO, a crystallization inhibitor contained in the flooring materials. An object of the present invention is to provide a manufacturing method that enables mass production.

In particular, the present invention is to provide a manufacturing method that can improve the productivity by making the crystallization to a certain level or more even if the zeolite is produced using a flooring material having a variety of component ratios.

Synthetic zeolite production method of the present invention for achieving the above object,

A first step of crushing the bottom ash of the thermal power plant into a powder form of 30 mesh or less using a continuous crusher; A second step of eluting and removing CaO component, which is a crystallization-blocking substance, by adding the bottom ash of the first step to a water tank; A third step of injecting the ground ash and the powdery alkaline material from which the CaO component is removed in the second step into a stirrer and stirring the mixed powder added uniformly; A fourth step in which the mixed powder uniformly stirred through the third step is introduced into a heating bath and heated, and the alkali material melted by heat is fused with the ground ash; A fifth step of mixing the fusion material which has undergone the fusing step in the fourth step, and water, an aluminum source and zeolite seed; A sixth step of aging by stirring the mixture of the fifth step with low temperature heating; A seventh step of crystallizing to increase the heating temperature of the mixture aged in the sixth step so that the synthesis and growth of the zeolite crystals are performed; And an eighth step of forming the product by filtration, washing with water, and drying the zeolite synthesized in the seventh step.

In the second step, the CaO component may be removed so that the CaO component is included in the range of 0.5 to 5% by weight based on the total weight of the floor ash, and preferably the CaO component is included in the range of 1 to 3% by weight. To remove it.

In addition, the second step includes a step 2-1 of injecting a ground ash into a water bath to elute and remove a CaO component that is a crystallization-interrupting substance; It may include; 2-2 step of dewatering the floor ash crushed to reduce the CaO component.

Step 2-1 includes the step 2-1a of immersing the bottom ash in a hot water of 50 to 80 ° C. for 0.5 to 2 hours and stirring to lower the CaO content of the bottom ash to 0.5 to 5% by weight; High pressure air is injected into the tank through a plurality of micro-holes formed in the inner surface of the tank to generate a plurality of small air bubbles in the tank, and the rising air bubbles are raised to form an upward flow, and the upward flow is mixed with the swirling flow of the stirrer. Step 2-1b to generate a mixed turbulence; may be further performed.

In step 2-1, when the step 2-1a or step 2-1b is performed, the CaO content is measured, and the measured value is equal to or greater than the allowable error range according to the remaining process execution time in comparison with the CaO content setting value. In step 2-1a, the step 2-1b is performed to discharge and then discharged. In step 2-1b, the second step, which is a CaO content measurement and automatic conversion process, is performed after the step 2-1a is again discharged. -1c step; can be made further.

Step 2-2 includes a step 2-2a of compressing and dehydrating the bottom ash pulverized product having reduced crystallization-interrupting substance to cake into a cake; Step 2-2b of putting the bottom ash pulverized in the cake state into a stirrer and crushed into a powder state; may be further made.

In the fourth step, an alkali material is selected from sodium hydroxide (NaOH) and sodium carbonate (Na ₂ CO ₃ ), and the powdered alkaline material is selected based on 100 parts by weight of the ground powder ground ash. The mixture may be mixed at ~ 200 parts by weight, and heat treated at 500 to 900 ° C. for 0.5 to 3 hours to fuse the ground ash and the alkali material.

In addition, the fifth process may be mixed with 200 to 1000 parts by weight of water, 5 to 25 parts by weight of aluminum source and 0.5 to 5 parts by weight of zeolite seed with respect to 100 parts by weight of the bottom ash produced in the fourth process. The aluminum source may be NaAlO ₂ .

In addition, the sixth process may be stirred for 3 to 12 hours at a temperature of 20 ~ 60 ℃, the seventh process may be performed for 2 to 72 hours crystallization in a batch reactor of 80 ~ 100 ℃ and atmospheric conditions.

Synthetic zeolite production method of the present invention by the above solution means,

Synthetic zeolite is manufactured using flooring materials with low recycling rate, but ground ash and alkali materials are mixed and mixed at high temperature and mixed at high temperature to make it as uniform as possible and then reacted with aluminum-containing materials to make crystallization. Zeolites can be produced. In particular, by lowering the CaO component contained as an impurity to 5% by weight or less to perform the zeolite synthesis reaction it is possible to improve the purity while enabling the production of various types of zeolite.

In addition, since there is no hydrothermal reaction, it can be manufactured in a batch reactor under atmospheric pressure, so that mass production by a continuous process is possible, thereby reducing production costs.

In addition, even if the floor material having a non-CaO component content is used, the content of CaO component during the synthesis reaction is maintained at a constant level so that the crystallization is kept constant, thereby providing a useful method for maintaining a constant production of zeolite. Was done.

1 is a manufacturing process flow chart according to an embodiment of the present invention.

2 is a manufacturing process flow chart according to another embodiment of the present invention.

Figure 3 is an analysis of zeolite 4A prepared by the production method of the present invention.

Figure 4 is a SEM photograph of the zeolite 4A prepared by the production method of the present invention.

Figure 5 is an analysis of zeolite NaP1 prepared by the production method of the present invention.

The present invention comprises a first step of pulverizing the bottom ash of the thermal power plant into a powder of 30 mesh or less using a continuous crusher; A second step of eluting and removing CaO component, which is a crystallization-blocking substance, by adding the bottom ash of the first step to a water tank; A third step of injecting the ground ash and the powdery alkaline material from which the CaO component is removed in the second step into a stirrer and stirring the mixed powder added uniformly; A fourth step in which the mixed powder uniformly stirred through the third step is introduced into a heating bath and heated, and the alkali material melted by heat is fused with the ground ash; A fifth step of mixing the fusion material which has undergone the fusing step in the fourth step, and water, an aluminum source and zeolite seed; A sixth step of aging by stirring the mixture of the fifth step with low temperature heating; A seventh step of crystallizing to increase the heating temperature of the mixture aged in the sixth step so that the synthesis and growth of the zeolite crystals are performed; And an eighth step of forming the product by filtration, washing with water, and drying the zeolite synthesized in the seventh step.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings. However, the accompanying drawings are only examples for easily describing the content and scope of the technical idea of the present invention, and thus the technical scope of the present invention is not limited or changed. In addition, it will be apparent to those skilled in the art that various modifications and changes can be made within the scope of the present invention based on these examples.

1 and 2 are a manufacturing process flow chart according to a preferred embodiment of the present invention.

Synthetic zeolite manufacturing method using the flooring material of the thermal power plant according to the present invention, the first step of the grinding step, the second step of removing the crystallization obstacle, the third step of the mixing powder stirring step, the fourth step of the fusion step, mixing The fifth process which is a process, the 6th process which is a aging process, the 7th process which is a crystallization process, and the 8th process which is a commercialization process are included.

The first process is a process of crushing the bottom ash, which is a process of crushing the large lump-shaped bottom ash generated inside the combustion furnace of the thermal power plant. In this first process, it is preferable that the flooring in the form of a lump is crushed in powder form as much as possible for uniform mixing. The apparatus used for the crushing may be pulverized using a continuous crusher (Hammer crusher or Scutter crusher) that can be continuously supplied by a conveyor belt. At this time, the grinding degree is pulverized to 30 mesh (mesh) or less, preferably pulverized into a powder of 30 ~ 60 mesh.

In the present invention, the use of coal ash bottom ash, which is a waste generated in a thermal power plant, increases the CaO content of coal ash by limestone input through a desulfurization process, and in particular, in the case of fly ash, the CaO component is mixed by using more than 20% by weight. The zeolite production has a disadvantage of low crystallinity. Therefore, by using a flooring material having a relatively CaO content of about 10% by weight, it is possible to easily reduce the CaO content, and to provide a method of maintaining a constant crystallinity even when various flooring materials are used.

Next, as shown in FIG. 2, a second process of removing the CaO component, which is a crystallization inhibitor, is performed.

The second step is a step of removing the CaO component which is an obstacle to the zeolite crystallization, can be divided into a 2-1 step of removing the CaO component, and a 2-2 step of dehydration, the CaO removal process Step 2-1 is step 2-1a, which is a hot water stirring step, step 2-1b, which is an air injection mixing step of injecting air injection to generate mixed turbulence, and step 2-1c, which measures CaO content. The second and second dehydration processes may be subdivided into a second-2a process of forming a cake and a second-2b process of pulverizing the cake.

In the step 2-1, the content of CaO is lowered to 5 wt% or less, preferably 3 wt% or less, to increase the zeolite crystallization rate, thereby enabling various types of zeolite synthesis. Removing the CaO component as much as possible is advantageous in improving reactivity, but considering economics, it is preferable to lower the content to 1 to 3% by weight based on the total weight of the ground ash, and then perform a subsequent reaction step. In particular, when a continuous zeolite synthesis is performed using a flooring having a high content of CaO, the second step is to lower the content of CaO and then crystallize.

Step 2-1a of the step 2-1, soaking the bottom ash crushed in a tank containing high temperature water of 50 ~ 80 ℃ 0.5-2 hours to facilitate the elution of CaO component from the bottom ash, and stirring Through the component dissolution is more easily made to finally lower the CaO content to at least 5% by weight or less preferably 3% by weight or less.

The ground ash may be made to eluate the CaO component in various ways. For example, a batch type of agitation type that is put into a water tank and agitated, a conveyor type that is settled on a conveyor belt and passes through a water tank, a horizontal water tank rotating method that forms a spiral vane on the inner surface of a horizontal water tank and moves it in one direction to discharge it. Multiple discharges can be applied by parallel connection.

In the step 2-1b, step 2-1b is an air injection mixing step of generating mixed turbulence. For example, a large number of micro-pores are formed on the inner surface of the tank and high pressure air is injected into the tank to generate a large number of small air bubbles. By mixing with the flow by vane to generate turbulence, CaO and water react with calcium hydroxide by increasing the contact frequency of the surface of the ground ash containing calcium oxide (CaO) and water with low concentration of calcium hydroxide (Ca (OH) ₂ ). The frequency of dissolution can be increased. In addition, as the small air bubbles rise while passing through the stacked floor ashes, the floor ashes may be easily mixed up or down, thereby increasing the contact frequency with water, thereby facilitating elution of CaO. In this case, various gases such as hydrogen carbon dioxide may be selected and injected into the gas to be injected.

Steps 2-1a and 2-1b may be sequentially performed, or only one of them may be selectively performed.

In addition, the 2-1a process and the 2-1b process may be selectively performed according to the CaO content of the ground ash through the 2-1c process, which is a CaO content measuring process.

For example, if the measured CaO content is higher than the target content by measuring the CaO content of the bottom ash pulverization step 2-1a through step 2-1c, the step 2-1a is newly performed, or the step 2-1a step In the process of performing the CaO content periodically measured if the measured CaO content is higher than the target content can be adjusted to increase the time to pass through the tank so that the CaO content at the discharge side is lower than the target content.

In addition, if the CaO content measured from the bottom ash pulverized by performing step 2-1a through the measurement of CaO content is higher than the target content, the step 2-1b is performed to mix the stirring method and the air injection method. CaO content can be reduced. The bottom ash pulverized after the step 2-1b is also measured by CaO content measurement process, if the measured CaO content is higher than the target content to perform step 2-1a or 2-1b again. Can be.

The CaO content measurement of the 2-1c process may be continuously measured in a continuous manner, or measured by a predetermined time unit to adjust the device speed. In this way, if the CaO content measurement process is additionally performed, even if the CaO content of the input material is changed, the CaO content of the bottom ash pulverized by the automatic control in this process can be lowered to a certain level or less, thus maintaining the quality of the final zeolite uniformly. It provides the effect. In the step 2-1c, which is a CaO content measuring step, the CaO content is preferably set to 5% by weight or less relative to the total mixture, and more preferably 3% by weight or less to improve the crystallinity.

In addition, the step of removing the CaO component was to complete any one of steps 2-1a and 2-1b and to perform an additional step according to the CaO content, in addition to the stirrer 2-1a process In the process of performing the stirring process by measuring the CaO content periodically, if the measured CaO content value is out of the range of 1% by weight compared to the set CaO content value can perform the step 2-1b to increase the CaO removal rate per hour.

For example, if the 2-1 step of removing the CaO component is performed for 1 hour, the CaO component is removed by the water tank stirring method of the 2-1a process, and the value measured by measuring the CaO content is measured at 30 minutes. When a difference of 1% by weight or more from the set value occurs, the ground ashes having a CaO content or less set within the set time may be provided by a method of injecting air to perform the step 2-1b.

Here, the determination of switching to step 2-1b during the process of step 2-1a is made by a difference between the CaO content set value and the CaO content measured value, and the error range with the CaO content set value is determined in the remaining time. It can be set to vary according to the data, it can be made to automatically convert according to the CaO content measurement results by the data.

In the CaO content measurement process (Step 2-1c), when the remaining time for performing the CaO component removal process (Step 2-1) is 30 minutes, the error range between the set value and the measured value is 1% by weight, and the remaining time is In 15 minutes, the error range between the set value and the measured value is converted into 0.4% by weight, and the process of step 2-1a is continued or converted to step 2-1b through the error range of the measured CaO content measured at each time point. Therefore, the CaO component can be removed quickly. That is, the measured measured value is compared with the CaO setting value according to the remaining time of performing the CaO component removal process from the measurement time point, and is determined to be within or above the error range set according to the remaining time. An automatic operation setting process may be included to re-perform step -1a or step 2-1b to lower the CaO content.

When the automatic operation setting is included as described above, the zeolite produced even when the flooring material having various CaO contents is added can be produced by similar crystallinity, so that the productivity can be maintained uniformly.

On the other hand, in the batch method and the horizontal water tank rotation method, by adding vibration or microwave to the water tank vessel, the CaO component dissolution is further increased by increasing the contact frequency of the water with low concentration of calcium hydroxide (Ca (OH) ₂ ) and the bottom ash in the tank. Can be promoted.

Next, the dehydration process 2-2 is a process of dehydrating the flooring ash obtained by performing the CaO component removal process 2-1. The centrifugal force or the pressurization method may be applied.

This 2-2 process includes the 2-2a process of compressing and dehydrating the bottom ash grind | pulverized material which reduced crystallization interference substance, and cake-forming, and the 2-2b process of crushing a cake is performed.

For example, the cake of the 2-2a process may be dewatered by pressurization using a continuous filter press.

In addition, step 2-2b is a step of crushing the compressed cake. Step 2-2b is a step of crushing the pulverized bottom ash pulverized by pressing into a stirrer including a crusher. At this time, the drying may be performed at the same time by applying heat in the crushing process to make the dry powder. The stirrer is composed of a heating jacket to crush the floor ashes agglomerated by heat supply and at the same time to evaporate moisture to powder the powder, or to dry the floor ashes agglomerated by a crushing roll that generates heat. Can be made at the same time. In addition, in the second-2b process, only the cake crushing process may be performed, and drying by heat may be performed together with combustion in the following heat treatment process.

In the third step of the mixing powder stirring step, the crystallization-interrupting material is a step of mixing and stirring the ground ash pulverized material, which has undergone the second step of lowering the CaO content, with the powdered alkali material.

The mixed alkali material may be selected from sodium hydroxide (NaOH) and sodium carbonate (Na ₂ CO ₃ ). In addition to the alkali material containing a sodium component; Alkali materials containing potassium and calcium or barium, such as potassium hydroxide, potassium carbonate, calcium hydroxide and barium hydroxide, may be selected and used.

It is preferable that such an alkali material is ground to 30 to 60 mesh like ground ash to be mixed in a powder form in a powder state to enable uniform mixing.

The mixing ratio is preferably 50 to 200 parts by weight of the powdered alkali material selected for 100 parts by weight of the ground powder ground ash. When the alkali material is mixed in an amount of 50 parts by weight or less, the formation of the aluminate ion source and the silicate ion source is inadequate, resulting in low crystallization. When the mixture is mixed in an amount of 200 parts by weight or more, the aluminate ion source and the silicate ion source It is preferable to mix within the above range because the degree of formation enhancement is insufficient.

In addition, the mixer used for mixing is preferably mixed uniformly using a ribbon mixer, it is possible to apply the CSTR method for a continuous process, for example, a plurality of ribbon mixers are installed in series and stay in each ribbon mixer. By controlling the time to make the continuous mixing can be possible. The stirring time of the mixing powder stirring step is made for 5 minutes to 60 minutes, preferably stirring for 10 to 20 minutes that can be sufficiently uniformly mixed with the flooring ash and alkali material.

In the fourth process, the fusion process is a process in which a uniformly stirred mixed powder is introduced into a heating bath and heated to fuse the alkali material and the ground ash. In the fourth process, the alkali material in the mixed powder is melted by the supplied heat to fuse with the floor ash grind. Therefore, when the alkali material and the bottom ash are uniformly mixed in powder form, the molten alkaline material and the bottom ash are fused 1: 1 to form an advantageous structure for the synthesis of zeolite.

That is, by heating, SiO ₂ in the main component of the flooring material is changed to Na ₂ SiO ₃ soluble in water or NaAlSiO ₄ soluble in an alkaline aqueous solution, thereby forming an aluminate ion source and a silicate ion source required for zeolite synthesis.

The heat treatment temperature in this fusion process is preferably formed at 500 ~ 900 ℃, 30 to 180 minutes are preferably made. That is, below 500 ° C., the alkali material does not melt well, so that the fusion with the floor ash is not made well. Above 900 ° C., the alkali material is excessively melted and agglomerated with neighboring alkali materials, thereby lumping together. It is preferable to apply heat.

At this time, when using sodium hydroxide (NaOH) as the alkali material, it is preferable to mix 100 to 120 parts by weight with respect to 100 parts by weight of the bottom ash, the fusion step is preferably to be fused at a temperature of 500 ~ 550 ℃.

In addition, in the case of using sodium carbonate (Na ₂ CO ₃ ) as an alkaline material, it is preferable to mix 50 to 200 parts by weight with respect to 100 parts by weight of the bottom ash, and to fuse at a temperature of 800 ~ 900 ℃ in the fusion process. Do. When the fusion is performed by applying heat below 600 ° C. using sodium carbonate, the yield is lowered because more than 50% of quartz or aluminum silicate contained in the ground ash is not involved in crystallization to zeolite. Therefore, it is desirable to be able to change the amorphous or water-soluble form which is easy to be used as a zeolite raw material by adjusting the heat treatment temperature according to the alkali material to be added.

Next, a mixing process, which is a fifth process, is performed. The fifth process is a process of mixing the bottom ash fusion material, which is subjected to the fusion process in the fourth process, water, aluminum source and zeolite seed.

The mixing ratio is 200 to 1000 parts by weight of water, 5 to 25 parts by weight of aluminum source and 0.5 to 5 parts by weight of zeolite seed with respect to 100 parts by weight of the bottom ash fusion produced in the fusion process.

When the water is mixed at 200 parts by weight or less, the amount of zeolite is lowered. When the mixture is mixed at 1000 parts by weight or more, the crystallization rate is slowed, so that the plant size increases during mass production. More preferably, it mixes 400-500 weight part. In addition, by adjusting the mixing amount of the water to increase the concentration of alkali in the mixture to produce a NaP1 zeolite having a stable structure, or to produce sodalite.

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

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

In order to perform the mixing process, which is the fifth process, a plurality of synthesis reactors accommodating each mixture may be formed, and may be installed in series so that mixing may be performed while sequentially passing through each synthesis reaction tank, or a plurality may be installed in parallel. It can be applied in such a way that each of them is fed separately, each reacts independently, and then a sequential release occurs.

The sixth step is a step of aging by stirring the mixture of the fifth step at 20 ~ 60 ℃ low temperature heating.

This process is a step of stirring so that the flooring melt is sufficiently dissolved in water, it is preferable to make the stirring for 3 to 12 hours. If the maturation time is less than 3 hours, the bottom remelt is not sufficiently dissolved in water, and the amount synthesized in the crystallization step is lowered. If it is more than 12 hours, the degree of crystallization is insufficient, so that the maturation is achieved by stirring within the above range. It is desirable to make it.

The seventh step is a step of increasing the heating temperature to 80 ~ 100 ℃ in the mixture aged through the sixth step to the synthesis and growth of zeolite crystals.

The seventh step of the present crystallization can be carried out in a hydrothermal reactor, but can also be carried out in a general batch reactor. Therefore, by installing a plurality of batch reactors in parallel to perform the crystallization reaction by the time difference in order to achieve a sequential discharge can be produced crystallized zeolite similar to the continuous process.

This seventh process is carried out for 2 to 72 hours to achieve crystallization, preferably to be crystallized in the reaction tank for 3 hours or more, and can be adjusted within the above range the execution time for performing the crystallization according to the type of zeolite have.

The eighth step is a process in which the zeolite synthesized through crystallization in the seventh step is filtered, washed with water and dried to produce a commercially used product.

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

The drying is made in the range of 90 ~ 100 ℃, it can be made through the continuous tunnel drying continuous drying.

In addition, the dried zeolite may be commercialized in a powder state, or may be used by further firing, or may be used by hot firing after molding in pellet or bead form.

The present invention will be described in more detail with reference to the following Examples.

1. 본 발명의 제올라이트 제조 1. Preparation of Zeolite of the Present Invention

-Coal bottom ash receiving and crushing process (1st process)

Coal bottom ash from Donghae thermal power plant was received.

The received coal bottoms were powdered up to 30 mesh (about 600 μm) through a crusher.

The powdered bottom ash was analyzed in XRF and the ingredients are shown in Table 1 below.

TABLE 1

As shown in Table 1, it can be seen that the CaO content is about 8% by weight. In addition, since the sum of SiO ₂ and Al ₂ O ₃ is about 81%, the purity of the zeolite synthesis is also expected to be 81% or more.

CaO removal process (2nd process)

The bottom ash was added to hot water at 90 ° C. in a batch tank and stirred for 1 hour to lower the CaO component to 7 wt% or less relative to the total weight.

The bottom ash pulverized with low CaO content was dehydrated by a compression method, and the compressed cake was crushed and supplied to a heat treatment process.

-Mixing powder stirring process and fusion process (3rd and 4th process)

100g of the ground ash was crushed and put into a mixer, and powdered sodium hydroxide was selected as an alkaline material, and 120g was added to the mixer, followed by stirring for 10 minutes to prepare a mixed powder.

The mixed powder of coal bottom ash and sodium hydroxide was added to a heating bath, and heated at 500 ° C. for about 1 hour to be fused.

-Mixing process, aging process and crystallization process (5th, 6th and 7th process)

100 g of the fused bottom ash mixture, 500 mL of water, and 1 g of zeolite 4A seed were added to the synthesis reactor.

In addition, since the molar ratio of SiO ₂ / Al ₂ O ₃ of the flooring material is 3.5, 30 g of NaAlO ₂ selected as the aluminum source was further added to adjust the molar ratio of SiO ₂ / Al ₂ O ₃ to 2.0.

The mixture was heated to a low temperature of 30 ° C. for 5 hours with stirring to allow the bottom ash fusion to be sufficiently dissolved in water.

The heating temperature of the mixture after aging was raised to 90 ° C. and stirred for 5 hours to proceed with crystallization.

-Zeolite commercialization process (8th process)

After crystallization of the zeolite was filtered, washed with deionized water and dehydrated, the zeolite was dried at 100 ° C. in a dry oven to produce a powdered zeolite 4A.

2. 제올라이트 4A 제조2. Manufacture of zeolite 4A

1) Example 1 - Zeolite 4A was prepared by the above method, but the CaO content was adjusted to 7 wt% or less with respect to the total weight of the floor ash by changing the process time in the CaO removal process.

2) Example 2 - Zeolite 4A was prepared by the preparation method, but the CaO component content was adjusted to 6 wt% or less based on the total weight of the bottom ash in the CaO removal process.

3) Example 3 - Zeolite 4A was prepared by the above preparation method, but the CaO component content was adjusted to 5 wt% or less based on the total weight of the bottom ash in the CaO removal process.

4) Example 4 - Zeolite 4A was prepared by the preparation method, but the CaO content was adjusted to 4 wt% or less based on the total weight of the floor ash in the CaO removal process.

5) Example 5 - Zeolite 4A was prepared by the above method, but the CaO content was adjusted to 3 wt% or less based on the total weight of the floor ash in the CaO removal process.

6) Example 6 was adjusted in the CaO step of removing the zeolite 4A prepared by the above method the amount of CaO component in the total weight of bottom ash crushed to less than 2% by weight.

7) Example 7 - Zeolite 4A was prepared by the above method, but the content of CaO component was adjusted to 1% by weight or less based on the total weight of the bottom ash in the CaO removal process.

8) Example 8 - Zeolite 4A was prepared by the above method, but the CaO content was adjusted to 0.5% by weight or less based on the total weight of the bottom ash in the CaO removal process.

9) Comparative Example 1 did not run the CaO step of removing the zeolite 4A prepared by the above method.

실험예1) 결정화도 측정Experimental Example 1) Crystallinity Measurement

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

[Equation 1]

Here, the product is a zeolite prepared in Examples 1 to 6, and the reference product is a commercial zeolite 4A or a commercial zeolite NaP1 manufactured by Wako.

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 , and other components. 0.02% by weight.

In addition, the crystallinity is a relative value when the crystallinity of the reference substance is 100%.)

In Example 1 to Comparative Example 1, the CaO component content and the crystallinity of the zeolite prepared by using the same for the total weight of the ground ash before the heat treatment process are summarized in Table 2 below.

TABLE 2

As shown in Table 2, Examples 1 to 8, which performed the CaO removal process, showed higher overall crystallinity than Comparative Example 1, which did not perform the CaO removal process, but Examples 1 to 2 were almost similar to each other to improve crystallinity. Was incomplete. It can be seen that the crystallinity was greatly improved from Example 3 having the CaO component content of 5 wt% or less, and in particular, the sharp improvement in crystallinity was shown in Example 5 of 3 wt% or less.

However, as in Example 8, in order to lower the CaO content to less than 0.5% by weight relative to the total weight, the stirring time in the water tank was increased by twice as much as in Example 5.

In order to improve the crystallinity, the CaO component removal process is performed, but the CaO content is set at 0.5 to 5% by weight based on the total weight, and the CaO content is set at 1 to 3% by weight to obtain high crystallinity. Most preferably, the CaO content is set to 3% by weight to obtain a high degree of crystallinity compared to the CaO component removal process, thereby improving productivity.

In addition, Figure 3 is an analysis of the zeolite 4A (Zeolite AB) and commercial zeolite 4A (Zeolite A-ref.) Prepared using the flooring according to the production method of the present invention, Figure 4 is an example SEM photograph of zeolite 4A prepared by the preparation method of FIG. 5. As can be seen it can be seen that the synthetic zeolite prepared by the production method of the present invention has a peak close to the commercial zeolite.

실험예2) CaO 제거공정 후 CaO함량측정Experimental Example 2) CaO Content Measurement after CaO Removal

1 kg of the bottom ash grinder having the content shown in Table 1 was added to a batch tank containing 30 L of hot water, and a CaO removal process was performed.

The batch type water tank has a structure in which a plurality of air injection hoses are communicatively coupled from the outside to supply high pressure air in the form of small droplets through the inner side and the bottom surface, and an agitating method using an agitator and an air injection method for forming air bubbles are selected. Can be carried out.

It was confirmed how much difference CaO removal efficiency in the stirring method and the air injection method and mixing method.

10) Example 9 -The stirrer was stirred for 30 minutes, and the stirrer was stirred for another 30 minutes, after which the CaO content was measured.

11) Example 10 - Air bubbles floating method was performed for 30 minutes, air injection method was further performed for 30 minutes, and after completion of CaO content was measured.

12) Example 11 -After stirring the stirrer method for 30 minutes, the air injection method was carried out for 30 minutes, CaO content was measured after completion.

13) Example 12 -The stirrer was stirred for 30 minutes, and then the stirrer was stirred for 30 minutes, and the CaO content was measured.

The CaO content measured by Examples 9 to 12 is shown in Table 3 below.

TABLE 3

When the CaO removal process is performed at the same time as referring to Table 3, it can be seen that the stirring method is more effective in reducing the CaO content than the air injection method. The stirring method can increase the fluid flow in the water tank and the air injection method is partially effective, but it is considered that the mixing degree is lowered when used alone because a large amount of precipitate is present.

In addition, it can be seen that the CaO content effect shows a high removal rate when the mixture of the stirring method and the air injection method of Example 12 is executed, and Example 9, which is performed only by the stirring method, also shows a high removal rate. However, in Example 10 and Example 11 performed by air injection alone, the CaO content was relatively low.

Therefore, when the mixing method of stirring and air injection of Example 12 is applied in the CaO removal process, the CaO removal process time can be shortened. However, it is desirable to reduce the CaO component to the desired target value in a short time by applying the case where the gap is large compared to the target CaO content value by increasing the energy consumption since the air injection method is additionally performed.

3. 본 발명의 제조방법으로 제올라이트NaP1 제조3. Preparation of Zeolite NaP1 by the Production Method of the Present Invention

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

In the second step (CaO removal step), the content of CaO component to the total weight of the flooring ash was adjusted to 7% by weight or less.

Sodium carbonate was selected as the alkaline material to be added in the third step (mixed powder stirring step).

In the fourth step (fusion process), the mixed powder of the bottom ash and sodium carbonate was introduced into a heating bath, and heated at a temperature of 850 ° C. for about 2 hours to fuse.

100 g of the bottom ash fusion fused in the fifth step, 500 mL of water, and 1 g of zeolite NaP1 seed were added to the synthesis reactor.

At this time, since the molar ratio of SiO ₂ / Al ₂ O ₃ was 3.5, NaAlO ₂ selected as an aluminum source was not added separately because the molar ratio of zeolite NaP 1 was the same as 3.5.

In the 7th process (crystallization process), crystallization was advanced, stirring at 90 degreeC temperature for 18 hours.

After crystallization of the zeolite was filtered, washed with deionized water, and dehydrated, the zeolite was dried at 100 ° C. in a dry oven to produce zeolite NaP1 in powder form.

16) Examples 14 to 20 -Prepared in the same manner as in Example 13, except that the CaO content of 6, 5, 4, 3, 2, 1, with respect to the total weight of the bottom ash in the second step (CaO removal step) The amount was adjusted to 0.5 wt% or less.

17) Comparative Example 2 -Prepared in the same manner as in Example 13, but without performing the second step (CaO removal step), the CaO content of the total weight of the flooring ash is about 8% by weight as shown in Table 1 .

Examples 13 to 20 and Comparative Example 2 adjusted the molar ratio of SiO ₂ / Al ₂ O ₃ to 3.5 using NaAlO ₂ selected as the aluminum source in the sixth step.

실험예3) 제올라이트NaP1 결정화도 측정Experimental Example 3 Measurement of Zeolite NaP1 Crystallinity

The crystallinity calculation was applied to the equation (1) of Experimental Example 1. The reference product here is Wako's commercial zeolite NaP1.

The measured binding degrees are shown in Table 4 below.

TABLE 4

As shown in Table 4, zeolite NaP1 also showed a significant increase in crystallinity from Example 15 in which the CaO content in the bottom ash was reduced to 5 wt% or less, as in zeolite 4A. It can be seen that more than 80% by weight of crystallinity suitable for commercialization.

In addition, the lower the CaO content in the bottom ash, it can be seen that the crystallinity is higher, but the second process (CaO component removal process) takes a long time to lower the CaO content as in the production of zeolite 4A Because of this, it is preferable to perform the zeolite manufacturing process by setting the level to 3% by weight.

It can be seen that the analysis of zeolite NaP1 (NaP1-B) prepared by the preparation method of Example 17 is shown in FIG. 5.

Claims

A first step of crushing the bottom ash of the thermal power plant into a powder form of 30 mesh or less using a continuous crusher; A second step including a step 2-1 of injecting the bottom ash of the first step into a water bath to elute and remove the CaO component, which is a crystallization-interrupting substance, and a step 2-2 of dewatering the bottom ash of the reduced CaO component fair; A third step of injecting the ground ash and the powdery alkaline material from which the CaO component is removed in the second step into a stirrer and stirring the mixed powder added uniformly; A fourth step in which the mixed powder uniformly stirred through the third step is introduced into a heating bath and heated, and the alkali material melted by heat is fused with the ground ash; A fifth step of mixing the fusion material which has undergone the fusing step in the fourth step, and water, an aluminum source and zeolite seed; A sixth step of aging by stirring the mixture of the fifth step with low temperature heating; A seventh step of crystallizing to increase the heating temperature of the mixture aged in the sixth step so that the synthesis and growth of the zeolite crystals are performed; Eighth step of producing a product by filtration, washing and drying the zeolite synthesized in the seventh step;

Step 2-1 of the second step,

Dipping the bottom ash in 0.5 to 2 hours in hot water at 50 to 80 ° C. and stirring to lower the CaO content of the bottom ash to 0.5 to 5 wt%;

High pressure air is injected into the tank through a plurality of micro-holes formed in the inner surface of the tank to generate a plurality of small air bubbles in the tank, and the rising air bubbles are raised to form an upward flow, and the upward flow is mixed with the swirling flow of the stirrer. 2-1b to generate a mixed turbulence;

When performing the step 2-1a or step 2-1b to measure the CaO content, compared with the measured value of the CaO content, if the value is more than the allowable error range according to the remaining process execution time, the second step in the step 2-1a And converting to step -1b to be discharged and then discharged, and in step 2-1b, performing step 2-1a again and then discharging the CaO content measurement and automatic conversion step 2-1c; Synthetic zeolite production method, characterized in that.
The method of claim 1,

In the second step

A method of producing a synthetic zeolite, comprising removing the CaO component so that the CaO component is in the range of 1 to 3% by weight based on the total weight of the floor ash.
The method of claim 1,

In step 2-2,

A step 2-2a of compressing and dehydrating the bottom ash pulverized product having reduced crystallization-blocking substance to cake into a cake;

2-2b step of crushing the bottom ash pulverized in the cake state into a stirrer and crushed in a powder state; synthetic zeolite manufacturing method characterized in that the further made.
The method of claim 1,

The fourth step,

As an alkaline substance, select one kind from sodium hydroxide (NaOH), sodium carbonate (Na 2 CO 3 ),

50 to 200 parts by weight of the powdered alkaline substance selected for 100 parts by weight of the ground powder ground ash is pulverized,

A method of producing a synthetic zeolite, characterized in that the bottom ash and the alkali material are fused by heat treatment at 500 to 900 ° C. for 0.5 to 3 hours.
The method of claim 1,

The fifth step,

A method for producing synthetic zeolite, characterized in that the mixture is mixed with 200 to 1000 parts by weight of water, 5 to 25 parts by weight of aluminum source and 0.5 to 5 parts by weight of zeolite seed, based on 100 parts by weight of the bottom ash produced in the fourth step.
The method of claim 5,

The aluminum source is a method of producing a synthetic zeolite, characterized in that NaAlO 2 .
The method of claim 1,

The sixth step

Synthetic zeolite production method characterized in that the stirring for 3 to 12 hours at a temperature of 20 ~ 60 ℃.
The method of claim 1,

The seventh step,

Synthetic zeolite production method characterized in that the crystallization is carried out for 2 to 72 hours in a batch reactor at 80 ~ 100 ℃ and atmospheric pressure conditions.