JP2004203731A - Method of manufacturing single crystal highly functional zeolite mainly made up of coal ash and apparatus therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of continuously manufacturing single crystal highly functional zeolite which is one of A type, X type or Y type and a manufacturing apparatus therefor. <P>SOLUTION: A secondary raw material is added into the coal ash to be a primary raw material and compound them so that the structural ratio of SiO<SB>2</SB>/Al<SB>2</SB>O<SB>3</SB>becomes a prescribed ratio of one of A-type, X-typ or Y-type single crystal zeolite, and mixed with an alkali aqueous solution. The zeolite raw material Z is heated by heat exchangers 5 and 4 and continuously charged into a heating dissolution vessel 2 to dissolve SiO<SB>2</SB>and Al<SB>2</SB>O<SB>3</SB>components in the alkali aqueous solution while controlling the temperature. The resultant dissolved raw material components are controlled to have a temperature suitable for the zeolite synthetic temperature by a reaction temperature controlling heat exchanger 4, then continuously charged into a fluidized disc type reactor 3, and are allowed to react with each other while being stirred successively by a multistage rotary disk 3a in the reactor to manufacture a zeolite precursor and the zeolite crystal is grown from the precursor to synthesize one of the A-type, X-type or Y-type zeolite. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

The present invention uses coal ash, which is waste, as a main raw material, and adjusts the composition ratio of SiO ₂ / Al ₂ O ₃ in the coal ash to one of A-type, X-type, and Y-type by adding an auxiliary material. The present invention relates to a method for continuously producing a single-crystal high-performance zeolite of any of A-type, X-type, or Y-type by preparing a predetermined ratio of single-crystal zeolite, and a production apparatus therefor.

  Zeolite is a silicate mineral belonging to an aluminosilicate containing silica and alumina having a regular three-dimensional structure and containing water of crystallization.It contains cation-exchangeable cations and contains weakly retained water, which is susceptible to reversible dehydration. It has features such as coupling and a three-dimensional network structure. Zeolite is used as a desiccant or deodorant due to its strong adsorptivity, and because it has cation exchange properties in aqueous solution, it is used for soil improvement materials, wastewater treatment, purification of fish ponds, etc. Further, since it has a catalytic action as a solid acid, it is sometimes used, for example, as a catalyst for gasoline production, and is also used as a molecular sieve for purifying lubricating oils.

  Zeolites are broadly divided into natural zeolites and synthetic zeolites. In particular, zeolites synthesized from coal ash are often called artificial zeolites. As natural zeolite, two or three types of zeolites are mainly produced as mineral resources, but because of natural minerals, it is inexpensive, but it has many impurities and the content of impurities is indeterminate. There is a problem in use that the function is low and the quality varies greatly depending on the content of impurities. Due to its low price, it is used in some fields of agricultural soil improvement and wastewater purification, and its demand is increasing year by year. However, natural minerals have a limited output and cannot meet demand.

  Synthetic zeolites are mainly produced from industrial raw materials. Conventionally, various kinds of single crystal zeolites having high purity have been synthesized by a batch type apparatus using sodium aluminate, water glass and caustic soda as main raw materials. This synthetic zeolite is a single crystal of high purity without impurities, and thus exhibits high functions. However, there are problems that the raw material is an industrial raw material and that the production cost is high due to small-scale production by a batch type apparatus. Therefore, the application fields are limited to special fields, and are not used in large-scale consumption fields such as agricultural soil improvement, general soil improvement, and purification of wastewater.

  Next, artificial zeolites are synthesized from coal ash by some manufacturers, and are manufactured and sold as artificial zeolites. Such an artificial zeolite is manufactured by a batch type or a semi-batch type device as disclosed in Patent Documents 1 to 3, for example.

  The above-mentioned artificial zeolite is mainly composed of P-type among various types of zeolites, and sometimes includes a mixed crystal zeolite containing a small amount of one to several types of zeolites and / or non-zeolites sodalite. Yes, manufactured by a batch type device. In order to synthesize single-crystal zeolite from waste coal ash, it is necessary to make certain narrow synthesis conditions different for each zeolite to be synthesized, but in a batch system, the synthesis conditions must be kept constant within a narrow range. Therefore, a mixed crystal zeolite containing a P-type zeolite as a main component is produced. In general, P-type zeolite has the smallest pore size of 2.6 mm, which is the smallest among many types of zeolites, and there is a problem that the use destination is limited even if the temporary and cation exchange capacities are equivalent to other zeolites. .

  Furthermore, since the artificial zeolite is manufactured by a batch apparatus as described above, the synthesis of a high-functional A-type, X-type or Y-type single-crystal zeolite has not been achieved until now, and a mixed crystal of each production batch has not been produced. In addition, since the purity of the P-type zeolite as the main component varies and the ratio of mixed crystals varies, there is a problem that the quality is not uniform. Due to such a problem, its use is not widely spread. In the above description, the single-crystal high-functional zeolite means that it independently contains one of the crystal types of A type, X type or Y type. For example, in the case of A type, other X type, Y-type and P-type ones do not contain, but this does not mean that anything other than zeolite crystals is not contained at all. This is the same in the following.

  Since the batch type apparatus has the above-mentioned problems, recently, a continuous production method and apparatus of zeolite have been proposed in, for example, Patent Documents 4 and 5.

  The example of Patent Document 4 relates to a method for continuously producing an artificial zeolite using a circulating fluidized tank and an apparatus therefor. According to this apparatus, stirring is performed relatively well, but a reaction product and a raw material are circulated by circulation. Since mixed backmixing occurs, a mixed crystal zeolite containing a P-type as a main component is synthesized, and there is a problem that any of A-type, X-type, and Y-type single-crystal high-performance zeolites cannot be selectively synthesized.

  The example of Patent Literature 5 is proposed to solve the problem in the example of Patent Literature 4, and the reaction process is divided into two processes, a tube contact reaction process and a rotating disk contact reaction process. In this method, a zeolite raw material is continuously passed through a contact reaction tube to produce a zeolite intermediate composition, and the intermediate composition is sequentially stirred by a multi-stage rotating disk in a rotating disk contact reaction step to produce a desired zeolite. .

  However, in the method of Patent Document 5, the reaction temperature for the initial reaction after melting is lower than the melting temperature of coal ash and auxiliary materials in the tube contact reaction step of the first step. When the initial reaction occurs at a high melting temperature, a precursor of P-type zeolite can be formed in addition to the precursor of A-type, X-type or Y-type zeolite, and a high-performance single-crystal zeolite of A-type, X-type or Y-type can be synthesized. However, there is a problem that the P-type zeolite is mixed crystal.

Further, in the invention of Patent Document 5, by adding one or two or more crystalline minerals having a specific Si / Al ratio to a zeolite raw material or a zeolite intermediate composition to cause a zeolite reaction, a wide variety of wastes are produced. Even when using as a raw material, a specific type of zeolite corresponding to the added crystalline mineral is induced, so that the Si / Al ratio is not adjusted to a predetermined value in advance. It is stated that waste having an arbitrary Si / Al ratio can be easily adopted as a zeolite raw material, but this is a case where a mixed crystal zeolite is mainly composed of a P-type zeolite. Crystalline high-performance zeolites (A type, X type, Y type) cannot be selectively produced. In addition, since a circulation step is also provided, backmixing occurs, so that a mixed crystal zeolite containing a P-type as a main component is synthesized, and an A-type, X-type or Y-type single-crystal high-functional zeolite cannot be synthesized. There was a problem.
Patent Literature 6 describes an invention relating to the production of A-type zeolite using coal ash as a main raw material, but the invention of Patent Literature 6 includes any one of A-type, X-type, and Y-type. There is no structure for selectively synthesizing single-crystal high-performance zeolites, and no method or apparatus for continuously producing these zeolites has been studied in the invention of Patent Document 6.
JP-A-6-321524 JP-A-6-321525 JP-A-6-321526 JP-A-10-324518 JP 2002-187715 A JP-A-6-100314

Accordingly, the present invention has been made in view of the above-mentioned problems in the proposed continuous production method and apparatus for artificial zeolite instead of the conventional production method using a batch apparatus, and improves the problems. At the same time, the main raw material is specified as waste coal ash, and the composition ratio of SiO ₂ / Al ₂ O ₃ in this coal ash is determined by adding auxiliary raw materials to each single crystal of A, X, or Y type. It is an object of the present invention to provide a method for continuously producing an A-type, X-type or Y-type single-crystal high-performance zeolite by preparing a zeolite at a predetermined ratio, and a production apparatus therefor. Things.

The configuration of the production method of the present invention made for the purpose of solving the above-mentioned problem is as follows. The coal ash serving as a main raw material is added with an auxiliary material serving as a SiO ₂ source or an Al ₂ O ₃ source, and A zeolite raw material production step in which the composition ratio of SiO ₂ / Al ₂ O ₃ is adjusted so as to be a predetermined ratio of any one of A-type, X-type and Y-type single-crystal zeolites, and the mixture is stirred and mixed with an aqueous alkali solution; Zeolite raw material component dissolving step in which the raw material is heated by a heat exchanger and continuously charged into a heating dissolver, and the SiO ₂ and Al ₂ O ₃ components in the raw material are dissolved in an alkaline aqueous solution while adjusting the temperature in the dissolver. A reaction temperature adjusting step of adjusting the obtained raw material component melt to a temperature suitable for a zeolite synthesis reaction in a reaction temperature controlling heat exchanger, and flowing the raw material component melt adjusted to a temperature suitable for the reaction into a fluidized circle. The zeolite precursor is manufactured by continuously charging the reactor into a reactor and sequentially reacting with stirring by a multi-stage rotating disk in the reactor to produce a zeolite precursor, and grow the zeolite crystals from the precursor, and form A, X, and Y types. A zeolite synthesis step of synthesizing any of the above zeolites.

Further, the configuration of the manufacturing apparatus of the present invention made for the purpose of solving the above-mentioned problem is such that the coal ash which is a main raw material is added with an auxiliary raw material which is a SiO ₂ source or an Al ₂ O ₃ source, The ash is mixed so that the composition ratio of SiO ₂ / Al ₂ O ₃ becomes a predetermined ratio of any one of A-type, X-type, and Y-type single-crystal zeolites, and is stirred and mixed with an aqueous alkali solution in a raw material production tank. The zeolite raw material production means and the zeolite raw material are heated by passing through a heat exchanger for heat recovery and a heat exchanger for reaction temperature control, and are continuously heated to a heating dissolver which is heated so that the temperature can be controlled by the heater. A zeolite raw material component dissolving means for dissolving the SiO ₂ and Al ₂ O ₃ components in the raw material in an aqueous alkali solution while adjusting the temperature in the dissolver while charging the raw material component obtained, Heat exchanger smell A reaction temperature control means for controlling a temperature suitable for the zeolite synthesis reaction, and a rotational speed control in the reactor by continuously charging the raw material component melt adjusted to a temperature suitable for the reaction into a fluid disk reactor. A zeolite precursor is produced by reacting while being sequentially stirred by a multistage rotating disk provided as possible, and a zeolite crystal is grown from the precursor to synthesize any one of A-type, X-type, and Y-type zeolite. It is characterized by comprising at least a zeolite synthesis means.

  In the above description, the zeolite precursor refers to a core crystal of zeolite, and is generated at an initial stage of the reaction after a raw material component melt is charged into a fluidized disk reactor.

  According to the present invention, in the above-described configuration, a fluidized-disc heating / dissolving apparatus having a multi-stage rotating disk inside the heating / dissolving apparatus can be used.

Further, in the present invention, the composition ratio of SiO ₂ / Al ₂ O ₃ is converted into a molar ratio by adding an auxiliary material and the Al ₂ O ₃ is 1, and the SiO ₂ is 1 to 5, preferably 1.20. formulated such that 4.25 can be synthesized a-type zeolite, also likewise be converted at a molar ratio, relative to Al ₂ O ₃ is 1, SiO ₂ is 1.77 to 10.77, preferably from 3.0 to X-type zeolite can be synthesized by mixing so as to obtain 6.0, and further, similarly in terms of molar ratio, Al ₂ O ₃ is 1, SiO ₂ is 2.5 to 12.0, preferably 4.6 to 8.0. Thus, a Y-type zeolite can be synthesized. Incidentally, auxiliary materials serving as the SiO ₂ source, water glass, silica sand, paper sludge ash, rice husk ash, waste glass, etc., is either 1 or 2 or more selected from a raw material containing SiO _2, also, Al ₂ The auxiliary raw material serving as the O ₃ source is any one selected from raw materials containing Al ₂ O ₃ such as sodium aluminate, aluminum hydroxide, aluminum dross, red mud, aluminum can, aluminum processing waste liquid, aluminum processing sludge, and the like. 2 or more.

  Further, in the configuration of the production apparatus of the present invention, it is possible to provide a cooling means for passing the synthesized zeolite through a heat recovery heat exchanger and a cooler for rapidly lowering the synthesized zeolite to a temperature below which synthesis does not proceed. It is also possible to provide a pressure adjusting means for keeping the internal pressure constant.

  Thus, the functions of A-type, X-type, and Y-type zeolites are known facts, but they are manufactured only by synthesis from industrial raw materials, and have high functions and a very wide range of use. In view of the fact that the field of use is currently limited due to the high price, the present inventor has proposed a single crystal comparable to A-type, X-type and Y-type zeolites synthesized from this industrial raw material. -If high-performance A-type, X-type, and Y-type zeolites are synthesized from coal ash, which is currently a landfill waste, the production cost will be significantly lower, and the fields of application will be agricultural soil improvement and drainage. It has been found that it will be used in large quantities in large-scale fields such as water purification and that it can contribute to the achievement of a recycling-based environmental society. As a result of intensive research, the present invention has been completed.

  More specifically, the present invention is the first technology in Japan for continuously synthesizing A-type, X-type or Y-type single crystals / high-purity high-performance zeolites using coal ash as a main raw material. In order to synthesize a Y-type zeolite with a single crystal, the blending ratio and blending conditions of the raw materials and the synthesis conditions must be kept constant within a narrow range for each zeolite, and the raw material dissolution, zeolite precursor synthesis, and zeolite synthesis It is necessary to prevent the raw materials of each step from being mixed, that is, to prevent back mixing. In this respect, in the apparatus using the heating dissolver (flowing disk type heating dissolver) and the flowing disk type heating reactor in the present invention, it is possible to easily manage and adjust the conditions necessary for synthesizing the single crystal zeolite. As a result, since backmixing does not occur, a method for continuously producing A-type, X-type, and Y-type single-crystal zeolites and an apparatus therefor can be invented.

  The present invention is as described above. According to the present invention, it is possible to continuously produce high-performance single-crystal zeolites (A type, X type, Y type) using coal ash as waste as a main raw material. As a result, the production cost is low, and its performance is comparable to zeolites synthesized from conventional industrial raw materials, so that it is extremely useful.

  Further, in the present invention, since coal ash, which is waste, is used as a main raw material as described above, the production cost is significantly lower, and the use field is large-scale use in large-scale fields such as agricultural soil improvement and wastewater purification. And an excellent effect of contributing to the achievement of a recycling-based environmental society can be obtained.

  Furthermore, in the present invention, by adjusting the rotation speed of the rotating disk in the fluidized rotating disk type reactor, the zeolite raw material component solution can be stirred and mixed without back mixing, and a sufficient contact reaction can be performed. Therefore, high purity can be obtained.

  In addition, in the present invention, in the zeolite production process, part of the heavy metal in the coal ash is dissolved and removed in the aqueous alkaline solution, so that the amount of heavy metal eluted from the synthesized zeolite conforms to environmental standards. can get.

  Next, an embodiment of the present invention will be described with reference to the drawings. In addition, the manufacturing method of the present invention will be described together with the description of the manufacturing apparatus of the present invention for performing the method. FIG. 1 is a perspective view showing an outline of a production apparatus according to an embodiment of the present invention, FIG. 2 is a sectional view showing an internal structure of a fluidized disk reactor in the production apparatus shown in FIG. 1, and FIG. (A) is a bird's-eye view, (b) is a side view showing a cross section, FIG. 4 is a flow chart showing the flow of zeolite production by the production apparatus of FIG. 1, and FIG. 5 is a single A type from coal ash. FIG. 6 is an X-ray analysis chart of X-type single crystal synthesis from coal ash, and FIG. 7 is an X-ray analysis chart of Y-type single crystal synthesis from coal ash.

In the figure, 1 is a raw material production tank for producing a raw material for producing zeolite (hereinafter referred to as zeolite raw material Z), 1a is a stirring blade provided in the raw material production tank 1, and 1b is a stirring blade 1a. A motor 2 for rotating is a heating dissolver for sufficiently dissolving the SiO ₂ and Al ₂ O ₃ components in the zeolite raw material Z produced in the raw material production tank 1 in an alkaline aqueous solution while controlling the temperature. A disk-type heat dissolver is used. Reference numeral 2a denotes a rotating disk which is provided horizontally and in multiple stages at appropriate intervals in the fluid disk type heating / melting device 2, and 2b denotes a rotating shaft which supports these rotating disks 2a at their central portions, and a motor 2c. To rotate the rotating disk 2a. The rotation speed of these rotating disks 2a can be adjusted to a predetermined speed by a motor 2c. Q is a heater using a heating medium or the like for supplying heat to the fluidized disk type heating and melting device 2 from outside. The fluidizing disk type heat melting device 2 can change the melting conditions by changing the conditions (temperature, flow rate) of the heat medium to be heat-exchanged. In addition, as the heating dissolver, a continuous contact tube dissolver or the like (not shown) can be used in addition to the fluidized disk heating dissolver 2 described above.

  Reference numeral 3 denotes a fluidized-disk reactor for dissolving the zeolite raw material component dissolved and generated in the fluidized-disk heating and dissolving device 2 to a temperature suitable for the reaction, and then continuously charging and reacting. The structure of the fluidized-disk reactor 3 is substantially the same as that of the fluidized-disk heating and dissolving device 2, and 3 a are provided in the fluidized-disk reactor 3 horizontally in multiple stages at appropriate intervals above and below. The rotating disks 3b are rotating shafts that support the rotating disks 3a at their centers, and are rotationally driven by a motor 3c to rotate the rotating disks 3a. The rotation speed of these rotating disks 3a can be adjusted to a predetermined speed by a motor 3c. Adjustment of the rotation speed of the rotating disk 3a, prevention of backmixing by the size, shape and number of stages of the rotating disk 3a and the inner tray 3d, control of reaction time, synthesis of zeolite single crystals corresponding to each type, and addition of each type Can be changed. The internal structures of the fluidized-disk heating and dissolving device 2 and the fluidized-disk reactor 3 will be described later in detail.

  Reference numeral 4 denotes a heat exchanger for controlling the reaction temperature provided between the fluidized-disk heating / melting device 2 and the fluidized-disk reactor 3. The heat exchanger 4 is fed from the raw material production tank 1 by the raw material supply pump P for heat recovery. Heat exchange between the zeolite raw material Z heated through the heat exchanger 5 and the zeolite raw material component melt supplied to the flowing disk type reactor 3 from the flowing disk type heating / melting device 2, This is for further heating Z while cooling the temperature of the dissolved zeolite raw material component to a temperature suitable for the reaction. The temperature can be adjusted by adjusting the flow rate and the flow rate of the zeolite raw material Z when passing through the heat exchanger 5, and can also be performed by bypassing the zeolite raw material Z by a bypass. it can.

  Reference numeral 6 denotes a cooler that cools the zeolite synthesized by the reaction in the fluid disk reactor 3 to a temperature below the temperature at which synthesis does not proceed quickly. Before being sent to the cooler 4, the synthetic zeolite extracted from the fluidized-disk reactor 3 passes through a heat exchanger 5 for heat recovery and is sent from the raw material production tank 1 by a raw material supply pump P. It is cooled by exchanging heat with the low-temperature zeolite raw material.

  Reference numeral 7 denotes a pressure control valve for keeping the pressure of the reaction system in the above-mentioned production apparatus constant. By operating the pressure control valve 7, the pressure in the reaction system can be kept constant, and the reaction solution can be prevented from being vaporized by boiling and vapor lock (flow-fixed) due to vaporization.

Next, since the internal structure of the fluidized disk heating and dissolving device 2 and the internal structure of the fluidized disk reactor 3 are substantially the same, the internal structure of the fluidized disk type reactor 3 will be described with reference to FIG. In FIG. 2, a fluid disk type reactor 3 includes a multi-stage rotating disk 3a, a rotating shaft 3b for horizontally supporting these rotating disks 3a at appropriate intervals in the vertical direction, and a motor 3c for rotating the rotating shaft 3b. An inner tray 3d provided between the rotating disks 3a and projecting in a ring shape from the inner surface of the fluidized disk reactor 3, a jacket heating tube JK provided outside the fluidized disk reactor 3 and its control device; It is composed of a sensor (not shown) and the like, and controls back mixing, a reaction time, and a reaction temperature, which are components for synthesizing a high-performance A-type, X-type, or Y-type zeolite. In FIG. 2, RT is a continuous inlet for the zeolite raw material component melt, and ZT is an outlet for the synthesized zeolite. As shown in FIG. 3, it is preferable that a plurality of baffles j and projections t are provided at arbitrary positions on the rotating disk 3a as necessary, and the inner tray 3d is provided with a fluidized disk reactor 3 as shown in FIG. It is preferable that the attachment portion to the R is formed into an R shape. The R shape of the baffle j and the projection t of the rotating disk 3a and the mounting portion of the inner tray 3d can further improve the action of preventing back mixing. Although not shown, an inner tray 2d having an R-shaped mounting portion is also provided on the fluidized-disk heating / melting device 2, and a baffle plate j and a projection t are provided on the rotating disk 2a. In addition, the dissolution of the SiO ₂ and Al ₂ O ₃ components in the raw material into the aqueous alkaline solution can be promoted.

Thus, the zeolite has a dissolving step in which the SiO ₂ source and Al ₂ O ₃ source in the raw material are dissolved in the aqueous alkaline solution, and a step of forming a precursor and crystallizing / growing the zeolite before crystallization of the zeolite. The synthesis is performed sequentially without mixing. When the above steps are mixed (the occurrence of back mixing), the synthesis of zeolite stops, a predetermined zeolite is not synthesized, and a P-type zeolite and finally a sodalite or an analcyme crystal are synthesized. The present invention suitably prevents backmixing from occurring by means of a fluidized-disk heating / melting device 2 and a fluidized-disk reactor 3, and controls the reaction time and reaction temperature to obtain desired zeolites (A type, X type, Y-type) can be synthesized.

  The method for producing a single-crystal high-performance zeolite using coal ash as a main raw material of the present invention is performed in an example of the above-described production apparatus. At the start of operation of this apparatus, an alkaline aqueous solution is introduced and circulated in the apparatus. The temperature inside the system is adjusted to the temperature required for the synthesis operation. When the temperature inside the apparatus reaches a predetermined temperature, the zeolite raw material is introduced into the heating and melting step, and the zeolite synthesis operation is started.

Hereinafter, the flow of the manufacturing process will be described in order. In the raw material manufacturing tank 1, an SiO ₂ source or Al ₂ O ₃ is added to an alkaline aqueous solution having a predetermined concentration according to the type of coal ash as a main raw material and the type of zeolite to be manufactured. An auxiliary material as a source is added so that the initial composition ratio of SiO ₂ / Al ₂ O ₃ in the coal ash becomes a predetermined ratio of the A-type, X-type or Y-type single crystal zeolite. The mixture is mixed and sufficiently stirred by the stirring blade 1a in the raw material production tank 1 to mix. At this time, a seed crystal of one of A type, X type and Y type corresponding to the type of zeolite to be synthesized is added. Although not shown, when the auxiliary material can be added as an aqueous solution such as sodium aluminate or water glass as an industrial product, the auxiliary material is not directly supplied to the raw material production tank 1 but directly to the fluidized disk reactor 3. Added. For example, an auxiliary raw material supply line is connected to the raw material supply line immediately before the fluidized disk type reactor 3, and the auxiliary raw material is supplied to the fluidized disk type reactor 3 together with the raw material supplied from the fluidized disk type heating / melting device 2. Added. Of course, the auxiliary raw material may be added by connecting the auxiliary raw material supply line directly to the fluidized disk reactor 3.

  Next, the zeolite raw material Z produced in the raw material production tank 1 is sent to the heat recovery heat exchanger 5 by the raw material supply pump P, and exchanges heat with the synthetic zeolite taken out of the fluidized disk reactor 3. Replace and heat. This is sent to a heat exchanger 4 for adjusting the reaction temperature, and heat exchange is performed between the fluidized disk type heating and melting device 2 and the zeolite raw material component melt supplied to the fluidized disk type reactor 3 to further heat. These heat exchangers may be of a tube ring type, a multi-tube type, or a double-tube type.

The zeolite raw material heated as described above is then continuously charged into a fluidized-disk heating and dissolving machine 2, and the SiO ₂ and Al ₂ O ₃ components in the zeolite raw material are removed in the fluidized-disk heating and melting device 2. Similarly, it is sufficiently dissolved in an aqueous alkali solution in the zeolite raw material and heated to a predetermined temperature. The dissolution temperature at this time is 85 ° C to 140 ° C, preferably 85 ° C to 120 ° C.

  Next, the zeolite raw material component melt dissolved in the fluidized disk type heat dissolver 2 is sent to the above-mentioned heat exchanger 4 for controlling the reaction temperature so that the temperature becomes a predetermined temperature (80 ° C. to 120 ° C.) suitable for the reaction. Adjust to. In the fluidized-disk heating / melting device 2, the temperature is raised to a temperature suitable for melting. However, the temperature suitable for melting is higher than the temperature suitable for precursor formation and single crystal growth. In 4, the temperature is adjusted to a predetermined temperature suitable for the reaction, and then supplied to the fluidized disk reactor 3.

  In the fluidized disk reactor 3, the zeolite raw material component solution continuously charged is moved from the center to the inner peripheral wall side of the reactor 3 by the rotating upper rotating disk 3a and the lower tray by the inner tray 3d. Is moved toward the center of the rotating disk 3a, and such movement is repeated from the upper stage to the lower stage of the rotating disk 3a.During the movement, the dissolved zeolite raw material component sufficiently reacts, and the zeolite precursor Body formation and single crystal growth can be produced with high efficiency. In addition, by adjusting the rotation speed of the rotating disk 3a, the stirring and mixing of the zeolite raw material component melt can be performed without back mixing, and a sufficient contact reaction can be performed. And the reaction can be continuously performed.

  The zeolite generated in the fluid disk reactor 3 is taken out, sent to a heat exchanger 5 for heat recovery, and exchanged with the zeolite raw material Z for cooling as described above. Since the cooling in the heat exchanger 5 alone is insufficient, the cooling is sent to the cooler 4 to reduce the temperature to a temperature at which the synthesis does not proceed quickly, thereby synthesizing the desired type of zeolite. In addition, in order to prevent solidification in the apparatus system when the manufacturing apparatus is stopped, the apparatus is replaced at once with soda. FIG. 4 shows a flow chart of the flow of the above series of manufacturing steps.

  Next, the raw material components used in the present invention will be described. In the present invention, coal ash is used as a main raw material as described above. In order to further improve the synthesis rate of the zeolite and to further shorten the synthesis time, the coal ash is pulverized or classified as a pretreatment. In the pulverization, it is preferable that the average particle diameter of the coal ash is 10 μm or less, and the average particle diameter of 30 μm or more is 1% or less. Classification is performed at 45 μm, preferably at 25 μm, and it is preferable that the particles be synthesized using smaller particles.

Thus, the synthesis of zeolite requires four kinds of compounds of SiO ₂ , Al ₂ O ₃ , Na ₂ O and H ₂ O. Coal ash contains SiO ₂ and Al ₂ O _3, but the amounts of these components do not match the proportions required for the synthesis of A-type, X-type and Y-type zeolites, and depend on the type of zeolite to be synthesized. , SiO ₂ or Al ₂ O ₃ becomes insufficient, and one of them becomes excessive as an unreacted component. In order to use this unreacted portion also in zeolite synthesis, a supplementary material is added to supplement the shortage. The auxiliary material may be either solid or liquid. When the zeolite of each type is produced on the basis of coal ash, the component deficient is Al ₂ O _{3 in} the case of type A, and Al ₂ O ₃ or SiO ₂ (in the case of coal ash) in the case of type X. (Depending on the content of SiO ₂ ) is a deficient component, and in the case of the Y type, SiO ₂ is a deficient component.

As auxiliary materials to be used, as an SiO ₂ source, for example, industrial materials containing SiO ₂ such as water glass, natural materials containing SiO ₂ such as silica sand, paper sludge incineration ash, rice husk incineration ash, waste glass, etc. Industrial wastes containing such SiO ₂ are mentioned.

Examples of the Al ₂ O ₃ source include industrial raw materials containing Al ₂ O ₃ such as sodium aluminate and aluminum hydroxide, aluminum dross, red mud, aluminum cans, aluminum processing waste liquid, and aluminum processing sludge. Industrial waste containing natural Al ₂ O ₃ .

The above-mentioned main raw material and auxiliary raw material are mixed and reacted with an aqueous alkali solution having a prescribed concentration to synthesize zeolite. As a raw material of the aqueous alkali solution, for example, an industrial raw material containing Na ₂ O such as sodium hydroxide and sodium carbonate is used. And industrial waste containing Na ₂ O such as various kinds of waste soda. In the above-mentioned apparatus, continuous synthesis of zeolite is started, and an aqueous alkaline solution to be removed after the synthesis can be collected and reused as a part of the alkaline aqueous solution. In addition, some heavy metals in coal ash are removed by dissolving in an aqueous alkaline solution.

  Next, the following raw materials, auxiliary raw materials, alkali components, and water are blended in molar ratios in Table 1 for each type of zeolite. In order to shorten the synthesis time, the prepared main raw material, auxiliary raw material and aqueous alkali solution are preferably aged at 80 ° C. or lower for 6 hours or more.

  Further, in order to shorten the synthesis time, it is more preferable to add the zeolite synthesized as a seed crystal to the prepared main raw material, auxiliary raw material and aqueous alkali solution at a ratio shown in Table 2 below. The zeolite used as the seed crystal may be a zeolite from a commercially available industrial raw material or a zeolite produced in the present invention. When using the zeolite produced according to the present invention, the amount of the zeolite should be 3% or more based on the weight of the zeolite alone. Further, it is more preferable to add the zeolite to be added after the zeolite is aged at room temperature or 80 ° C. or lower in an aqueous alkali solution prepared in advance.

Next, conditions for synthesizing zeolite in the production apparatus of the present invention will be described.
(1) Flow rate of main raw material, auxiliary raw material, and aqueous alkali solution in the equipment during synthesis Maintain the flow velocity at 0.3 m / sec or more so that coal ash does not settle in the equipment. When the coal ash is pulverized, the flow velocity can be set to 0.2 m / sec or more.
(2) Number of rotations of the rotating disk in the fluidized rotating disk reactor The rotating disk is adjusted so that the flow of the raw materials prepared in the fluidized rotating disk reactor becomes a Reynolds number from 10 5 to 10 6. Rotate. Preferably, the rotation speed at which the Reynolds number becomes 50,000 to 150,000 is good.
(3) Synthesis temperature In the form of zeolite, 90 ° C. to 105 ° C., preferably 98 ° C. to 102 ° C. for type A, 85 ° C. to 100 ° C. for X type, preferably 85 ° C. to 90 ° C., Y type In this case, the temperature is from 85 ° C to 105 ° C.
(4) Synthesis time In the case of zeolite type A, 1 hour to 3 hours, preferably 2 hours to 3 hours, for X type, 2 hours to 6 hours, preferably 3 hours to 4 hours, In the case of the Y type, the time is 2 hours to 6 hours, preferably 3 hours to 4 hours.

  Next, examples of the present invention will be described. Table 3 below shows the proportions of the zeolite production raw materials in each type.

  Next, Table 4 shows the synthesis conditions of each type of zeolite production raw material.

  As a result of X-ray analysis of the zeolite synthesized in the above example, synthesis of A, X, and Y types was confirmed. These analysis results are shown in FIG. 5 as an A-type single crystal synthetic X-ray analysis diagram from coal ash, FIG. 6 as an X-type single crystal synthesis X-ray analysis diagram from coal ash, and FIG. It is shown as a type single crystal synthetic X-ray analysis diagram.

  INDUSTRIAL APPLICABILITY The present invention makes it possible to continuously and inexpensively produce high-performance single-crystal zeolites (A type, X type, Y type) using coal ash as waste as a main raw material. It can be used in large quantities in large-scale fields such as wastewater purification, and can contribute to the achievement of a recycling-based environmental society.

FIG. 1 is a perspective view illustrating an outline of a manufacturing apparatus according to an example of the present invention. FIG. 2 is a cross-sectional view showing an internal structure of a fluidized-disk reactor in the manufacturing apparatus of FIG. 1. 3 is an enlarged view of a rotating disk of the fluidized disk reactor of FIG. 2, (a) is a bird's-eye view, and (b) is a side view showing a cross section. FIG. 2 is a flowchart showing a flow of zeolite production by the production apparatus of FIG. 1. The X-ray analysis figure of the type A single crystal synthesis from coal ash. The X-ray single crystal synthesis X-ray analysis figure from coal ash. The X-ray analysis figure of Y-type single crystal synthesis from coal ash.

Explanation of reference numerals

1 Raw material production tank
1a Stirrer blade
1b Motor 2 Flowing disk heating and melting machine
2a Rotating disk
2b Rotary axis
2c motor 3 fluid disk reactor
3a Rotating disk
3b Rotary axis
3c motor
3d Inner tray 4 Heat exchanger for reaction temperature control 5 Heat exchanger for heat recovery 6 Cooler 7 Pressure control valve P Material supply pump Q Heater
JK Jacket heating tube j Baffle plate t Projection Z Zeolite raw material

Claims (11)

An auxiliary material as an SiO ₂ source or an Al ₂ O ₃ source is added to coal ash as a main raw material, so that the composition ratio of SiO ₂ / Al ₂ O _{3 in} the coal ash is A type, X type, or Y type. A zeolite raw material manufacturing step in which a single crystal zeolite is blended so as to have a predetermined ratio, and agitated and mixed with an aqueous alkali solution, the zeolite raw material is heated by a heat exchanger and continuously charged into a heating dissolver, and the melting is performed. A zeolite raw material component dissolving step of dissolving the SiO ₂ and Al ₂ O ₃ components in the raw material in an alkaline aqueous solution while controlling the temperature in the vessel, and a zeolite synthesis reaction of the obtained raw material component melt in a heat exchanger for controlling the reaction temperature A reaction temperature adjusting step of adjusting the temperature to a temperature suitable for the reaction, continuously feeding the raw material component melt adjusted to a temperature suitable for the reaction into a fluidized disk reactor, and agitating sequentially with a multi-stage rotating disk in the reactor. A zeolite precursor by producing the zeolite precursor, and growing a zeolite crystal from the precursor to synthesize an A-type, X-type, or Y-type zeolite. A method for producing a single-crystal high-performance zeolite using coal ash as a main raw material.   The method for producing a high-performance single-crystal zeolite using coal ash as a main raw material according to claim 1, wherein the heating dissolver is a fluidized disk type heating dissolver having a multi-stage rotating disk therein. The composition ratio of SiO ₂ / Al ₂ O ₃ was adjusted so that the auxiliary material was added, and the molar ratio of Al ₂ O ₃ was 1 and the SiO ₂ was 1 to 5, preferably 1.20 to 4.25. 3. The method for producing a high-performance single-crystal zeolite using coal ash as a main raw material according to claim 1 or 2, wherein the zeolite is synthesized. The composition ratio of SiO ₂ / Al ₂ O ₃ is adjusted so that the auxiliary material is added, and the molar ratio of Al ₂ O ₃ is 1, and the ratio of SiO ₂ is 1.77 to 10.77, preferably 3.0 to 6.0. 3. The method for producing a high-performance single-crystal zeolite using coal ash as a main raw material according to claim 1 or 2, wherein the zeolite is synthesized. The composition ratio of SiO ₂ / Al ₂ O ₃ was adjusted so that the auxiliary material was added, and the molar ratio of Al ₂ O ₃ was 1 and the SiO ₂ was 2.5 to 12.0, preferably 4.6 to 8.0. 3. The method for producing a high-performance single-crystal zeolite using coal ash as a main raw material according to claim 1 or 2, wherein the zeolite is synthesized. Auxiliary materials to be SiO ₂ source, water glass, silica sand, paper sludge ash, rice husk ash, waste glass, etc., any of claims 1 to 5 is either 1 or 2 or more selected from a raw material containing SiO ₂ A method for producing a single-crystal high-performance zeolite using such coal ash as a main raw material. Auxiliary materials to be Al ₂ O ₃ source, sodium aluminate, aluminum hydroxide, aluminum dross, red mud, aluminum cans, one for aluminum machining waste, processed aluminum sludge, etc., is selected from a raw material containing Al ₂ O ₃ A method for producing a high-performance single-crystal zeolite using the coal ash according to any one of claims 1 to 5 as a main raw material. An auxiliary material as an SiO ₂ source or an Al ₂ O ₃ source is added to coal ash as a main raw material, so that the composition ratio of SiO ₂ / Al ₂ O _{3 in} the coal ash is A type, X type, or Y type. A zeolite raw material producing means for preparing a single crystal zeolite of any one of the above, so that the zeolite raw material is stirred and mixed with an aqueous alkali solution in a raw material production tank, a heat exchanger for heat recovery of the zeolite raw material, and a reaction temperature control. warmed by passing through a use heat exchanger, SiO ₂ in the raw material with temperature control continuously charged into the heating dissolver which is temperature-controllable heating within the dissolver by the heater, Al ₂ O ₃ A zeolite raw material component dissolving means for dissolving the components in an alkaline aqueous solution, a reaction temperature adjusting means for adjusting the obtained raw material component melt to a temperature suitable for a zeolite synthesis reaction in the reaction temperature adjusting heat exchanger, Appropriate The raw material component melt that has been adjusted at a time is continuously charged into a fluidized disk reactor, and reacted while being sequentially stirred by a multi-stage rotating disk provided with a rotational speed adjustable in the reactor to form a zeolite precursor. Producing a zeolite crystal from the precursor and synthesizing a zeolite of any of A-type, X-type, and Y-type with at least a zeolite synthesizing means; Single crystal high performance zeolite manufacturing equipment.   9. The apparatus for producing a high-performance single-crystal zeolite using coal ash as a main raw material according to claim 8, wherein the heating dissolver is a fluidized disk type heating dissolver having a multi-stage rotating disk therein.   10. A high-performance single crystal using coal ash as a main raw material according to claim 8 or 9, further comprising a heat recovery heat exchanger for cooling the synthesized zeolite to a temperature below which synthesis does not proceed quickly and cooling means for passing through a cooler. Zeolite manufacturing equipment. The apparatus for producing a high-performance single-crystal zeolite using coal ash as a main raw material according to any one of claims 8 to 10, further comprising pressure adjusting means for maintaining a constant pressure in the apparatus.

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