TWI505989B - A method for preparation of zeolite - Google Patents

Description

Method for preparing zeolite

This invention relates to a process for the preparation of zeolites, and more particularly to a process for preparing zeolites from aqueous sludges containing cerium oxide and aluminum oxide. The invention also relates to a process for preparing an amorphous zeolite block, which is a process for preparing an amorphous zeolite block from a mixture comprising an aqueous slurry of cerium oxide and alumina and a metakaolin.

Zeolite is an aluminosilicate mineral containing a water-frame structure. Its structure is based on a tetrahedron (SiO ₄ or AlO ₄ ) of cerium oxide or aluminum oxide, and is connected to the four sides of yttrium and aluminum by oxygen atoms. The three-dimensional skeleton structure. The porous structure of the zeolite also allows the zeolite to have characteristics such as adsorption, ion exchange and catalyst, and thus can be used for gas adsorption, ion exchange, soil conditioner or catalyst carrier.

According to its source, zeolite can be divided into: (1) natural zeolite, which is obtained from natural minerals; (2) synthetic zeolite, which is a zeolite synthesized by chemical agents for special purposes, but it is still not widely used due to its high price; (3) Resource-regenerated zeolite (Zhengsheng Zeolite), which is a zeolite that has been regenerated from industrial waste such as coal ash, paper ash, or aluminum slag, which is cheap and has stable performance and quality, and can be used as industrial raw materials or people's livelihood. Use of environmentally friendly materials.

Among them, the zeolite is mainly prepared by using fly ash as raw material to prepare zeolite. Application and research direction, but because fly ash easily contains heavy metals, such as zinc ions or lead ions, it is necessary to remove heavy metals before using fly ash. This step will increase the cost and time of the zeolite process, so it is effective to seek other waste materials. The preparation of zeolite is a problem that is currently being studied.

In addition, the Taiwan Reservoir deposits an average of about 14 million cubic meters of silt per year. Mud seriously shortens the service life of the reservoir. It is necessary to strengthen the dredging operation to prolong the life of the reservoir. However, the large amount of silt cleared is about 4 million cubic meters per year, and its stacking method has become the primary problem. At present, the main resource treatment method for reservoir silt is to make the reservoir silt into lightweight aggregate, which can be applied to the main material of concrete on building materials, so that the reservoir sludge can be recycled to produce products with economic value, but the price is Lightweight aggregates above natural output, thus contributing to the promotion of reservoir sludge reuse.

Therefore, in order to consume a large amount of reservoir sludge deposited each year, other resources are added. The birth method is a necessary research and development problem, but few studies have been conducted to investigate the method by which reservoir sludge can be used to prepare zeolite.

The term "aqueous sludge containing alumina and cerium oxide" as used in the present invention includes, but is not limited to, an aqueous sludge containing a source of cerium and an aluminum source without heavy metals. The term "aqueous silt" includes, but is not limited to, water transport silt such as reservoir silt, river silt, lake silt, harbour silt or canal silt. In a preferred embodiment, the aqueous sludge comprising alumina and cerium oxide refers to reservoir sludge.

The term "alkaline solution" as used in the present invention includes but is not limited to having an alkali metal ion A solution of a hydroxide such as a solution of lithium, sodium, potassium metal ion hydroxide or the like.

The invention provides a method for preparing a zeolite, comprising the steps of: (a) providing an aqueous sludge comprising alumina and cerium oxide; (b) mixing the aqueous sludge with a hot alkaline solution to obtain an alkaline sludge (c) subjecting the alkaline sludge to hydrothermal treatment to form a zeolite slurry; and (d) subjecting the zeolite slurry to a treatment for lowering the pH value of the zeolite slurry. In a specific embodiment, after the step (d), the step of subjecting the zeolite slurry to drying and grinding into a powder may be further included. In a preferred embodiment, the zeolite mud treated by reducing the pH is dried at a temperature of about 90 to 200 ° C to form agglomerates, which are agglomerated and ground to a powder state. The powder particles can pass through a screen of about 20 to 50 mesh. In a more preferred embodiment, wherein the drying process is carried out at a temperature ranging from 100 ° C to 150 ° C. In another embodiment, after the dried zeolite slurry is further ground into a powder, the powder can pass through a 30 mesh screen; in a preferred embodiment, the pH is lowered. The treated zeolite mud is dried at 120 ° C to form agglomerates and ground into a powder

In a specific embodiment, the steps of (a) and (b) may further comprise the step of reducing the water content of the aqueous sludge or treating the aqueous sludge by calcination. In a preferred embodiment, the step of reducing the water content of the aqueous sludge may be followed by the step of treating the aqueous sludge by calcination. In another embodiment, the calcining method is carried out at a temperature ranging from 350 ° C to 1200 ° C; in a preferred embodiment, the calcining method is at a temperature ranging from 550 ° C to 1050 ° C. get on. In a more preferred embodiment, the aqueous sludge treated by the simmering method may be subjected to a step of grinding and sieving.

In the step (a), the water content of the aqueous sludge ranges from about 10% to 90%. In a preferred embodiment, the water content ranges from 20% to 65%.

In a specific embodiment, the step of reducing the water content of the aqueous sludge refers to Reducing the water content of the aqueous sludge to between 20% and 60%; in a preferred embodiment, the step of reducing the water content of the aqueous sludge means reducing the water content of the aqueous sludge to 25% to Between 45%; in a more preferred embodiment, the aqueous sludge has a water content of 25% and can be directly mixed with a hot alkaline solution.

In the step (b), the aqueous sludge treated by the calcination method or the non-sintering method is further mixed with the hot alkaline solution. In a preferred embodiment, the aqueous sludge and the hot alkaline solution are mixed. The mixing weight ratio ranges from 1:10 to 1:3. The term "hot alkaline solution" as used in the present invention includes, but is not limited to, sodium hydroxide (NaOH) solution, potassium hydroxide (KOH) solution, lithium hydroxide (LiOH) solution, sodium carbonate (Na ₂ CO ₃ ) solution. Or sodium bicarbonate (NaHCO ₃ ) solution. In a preferred embodiment, the hot alkaline solution refers to a sodium hydroxide solution. In another embodiment, the hot alkaline solution has a concentration ranging from about 1 M to about 20 M, and the hot alkaline solution has a temperature in the range of from about 25 ° C to about 99 ° C. In a preferred embodiment, the concentration of the hot alkaline solution ranges from 3 M to 15 M, and the temperature of the hot alkaline solution ranges from 30 ° C to 90 ° C.

In the step (c), the hydrothermal treatment has a temperature ranging from about 60 ° C to 300 ° C. And the treatment time of the hydrothermal treatment is about 3 to 36 hours. In a preferred embodiment, the hydrothermal treatment is carried out at a temperature ranging from 100 ° C to 250 ° C for a treatment time of from 6 to 24 hours.

The term "hydrothermal treatment" as used herein includes, but is not limited to, the use of water as a medium, plus an appropriate temperature to create pressure in a closed reactor for reaction.

In step (d), the hydrothermally treated zeolite slurry is subjected to lowering the zeolite. Treatment of the pH of the mud (pH). In a specific embodiment, the treatment for lowering the pH value of the zeolite slurry includes, but is not limited to, any means that can be used to reduce the pH, such as de-neutralization with water, deionized water or acidic solutions, or Lowering the pH of the zeolite slurry. In a preferred embodiment, the treatment for lowering the pH value of the zeolite slurry means that the zeolite slurry is washed with deionized water to adjust the pH of the zeolite slurry to (pH) to 8-10. In a more preferred embodiment, the zeolite slurry is washed with deionized water to a pH of pH = 9.

In another embodiment, the step of separating the zeolite slurry and the alkaline solution may be further included before the treatment for lowering the pH value of the zeolite slurry. In a preferred embodiment, the step of separating the zeolite slurry and the alkaline solution comprises, but is not limited to, separating the zeolite slurry and the alkaline solution by pressure filtration or centrifugation. In a more preferred embodiment, after the hydrothermally treated zeolite slurry is filtered by centrifugation, the zeolite slurry and the alkaline solution are separated, and the treatment is carried out to lower the pH value of the zeolite slurry.

After the zeolite or zeolite powder obtained by the method for preparing zeolite according to the present invention, the zeolite or zeolite powder may be further treated by calcination. In a specific embodiment, the temperature of the calcining method ranges from 200 ° C to At 500 ° C, the basic properties of the zeolite or zeolite powder, such as ion exchange, can be enhanced.

In the preferred embodiment, the zeolite is selected from the group consisting of P-type zeolite (Zeolite P), faujasite (Faujasite), hydroxic acid (Hydroxysodalite), and hydrogen. A group consisting of Hydroxycancrinite.

The aqueous sludge containing alumina and cerium oxide is subjected to the above-mentioned step of preparing zeolite Afterwards, the zeolite composition obtained includes, but is not limited to, Zeolite P, Faujasite, Hydroxysodalite, and Hydroxycancrinite, ie, The type of the obtained zeolite may be a two-phase zeolite, such as a combination of faujasite and hydroxide vanadium or a combination of hydroxide vanadite and calcium oxyhydrocarbazite. Alternatively, it may be a single phase zeolite, that is, the obtained zeolite type. It is a P-type zeolite, a faujasite, a hydroxyapatite or a hydrated nepheline. Therefore, the type of zeolite obtained may vary depending on the conditions in the various steps of the method for producing zeolite of the present invention.

In addition, the "Hydroxysodalite" mentioned in the present invention is A type of sodalite (Sodalite), so the zeolite species obtained by the present invention may further comprise any kind of sodalite; in the same way, the "Hydroxycancrinite" mentioned in the present invention is a calcite ( Cancrinite) is a kind, and thus the zeolite species obtained by the present invention may further comprise any of the classes of the smectite.

The invention also provides a method for preparing an amorphous zeolite block, comprising the steps of: (a) providing a mixture of an aqueous slurry comprising alumina and cerium oxide and a metakaolin; (b) providing the mixture with a hot alkaline The solution is mixed to obtain an alkaline mixture; (c) the basic mixture is formed into a specific shape by molding; and (d) the alkaline mixture is subjected to a curing treatment. In a specific embodiment, the step of treating the alkaline mixture by a bulk thermal hardening method may be further included between the steps (c) and (d). In a preferred embodiment, the block thermosetting method has a temperature in the range of 20 ° C to 95 ° C, and the block thermosetting method has a processing time of about 5 minutes to 12 hours; In the embodiment, the block thermosetting method is carried out at a temperature ranging from 20 ° C to 95 ° C, and the treatment time of the method is from 10 minutes to 8 hours.

The term "block thermosetting" as used in the present invention means including but not limited to an object. Subject to temperature, resulting in a change in the physical or structural hardness or strength of the object.

In the step (a), the water content of the aqueous sludge ranges from about 10% to 90%. In a preferred embodiment, the water content ranges from 25% to 65%. In a specific embodiment, the metakaolin is formed by kaolin first treated at a high temperature between about 450 ° C and 1100 ° C. In a preferred embodiment, the metakaolin is from kaolin at 550 ° C to 1000 ° C. The mixture is obtained after high temperature treatment, and the mixed weight ratio of the aqueous sludge to the metakaolin ranges from 5:1 to 1:4. In a more preferred embodiment, the mixing weight ratio of the aqueous sludge to the metakaolin ranges from 4:1 to 2:3.

In step (b), the mixture is mixed with a hot alkaline solution. In a preferred embodiment, the mixture weight ratio of the mixture to the hot alkaline solution ranges from 3:1 to 2:3. The term "hot alkaline solution" as used in the present invention includes, but is not limited to, sodium hydroxide (NaOH) solution, potassium hydroxide (KOH) solution, lithium hydroxide (LiOH) solution, sodium carbonate (Na ₂ CO ₃ ) solution and Sodium bicarbonate (NaHCO ₃ ) solution. In a preferred embodiment, the hot alkaline solution refers to a sodium hydroxide solution. In another embodiment, the hot alkaline solution has a concentration ranging from about 1 M to about 20 M, and the hot alkaline solution has a temperature in the range of from 25 ° C to 99 ° C. In a preferred embodiment, the hot alkaline solution has a concentration ranging from 3 M to 15 M, and the hot alkaline solution has a temperature ranging from 30 ° C to 90 ° C.

In the step (c), the alkaline mixture can be formed into a specific shape by molding. In one embodiment, the molding method refers to a slip casting method or an extrusion molding method, and in a preferred embodiment is an extrusion molding method. In another embodiment, the particular shape refers to a tubular shape, Honeycomb tubular, columnar or brick; in a preferred embodiment, the particular shape refers to a tubular or columnar shape; in a more preferred embodiment, wherein the brick is a tile-like, perforated brick Shape, I-shaped brick or general brick. As used herein, "forming method" means a method comprising, but not limited to, having a fixed shape of an object (referred to herein as an alkaline mixture) by any means. The term "slurry forming" as used herein includes, but is not limited to, filling an object (referred to herein as an alkaline mixture) into a mold such that the object has the shape of the mold; It can be of any shape, depending on the desired shape of the final product. Furthermore, the term "extrusion molding" as used herein includes, but is not limited to, imparting a particular shape to the object by imparting a certain amount of pressure to the object.

In the step (d), the temperature of the curing treatment ranges from about 60 ° C to 300 ° C, and the treatment time of the curing treatment is about 3 to 36 hours. In a preferred embodiment, the curing treatment is carried out at a temperature ranging from 120 ° C to 250 ° C for a period of from 4 to 24 hours. The term "conservation treatment" as used in the present invention includes, but is not limited to, means that the formed alkaline mixture block is placed in a closed reaction tank which is subjected to steam in the tank to cause mineral species in the block. Converted to zeolite minerals.

In a preferred embodiment, the zeolite type obtained by the above method for preparing an amorphous zeolite block is selected from the group consisting of zeolite A (Zeolite A), zeolite P (Zeolite P), and oblique calcium. Group of zeolite (Wairakite), analcime (Analcime) and faujasite (Faujasite).

The aqueous sludge containing alumina and cerium oxide is subjected to the above-mentioned step of preparing an amorphous zeolite block, and the obtained amorphous zeolite block type includes, but is not limited to, zeolite A. (Zeolite A), P-type zeolite (Zeolite P), oblique lime zeolite (Wairakite), analcime (Analcime) and faujasite (Faujasite) composition group, that is, the obtained zeolite block type can be a two-phase zeolite, For example, the type A zeolite and the P type zeolite coexist, or the composition of the zeolite and the faujasite coexist, or a single phase zeolite, that is, the obtained zeolite block type is A type zeolite, P type zeolite, oblique calcium zeolite, square Zeolite or faujasite. Therefore, the type of the obtained zeolite block varies depending on the conditions in the various steps of the method for producing an amorphous zeolite block of the present invention.

Figure 1. Schematic diagram of the process of preparing zeolite powder and amorphous zeolite block.

Figure 2. Laser particle size distribution map of reservoir silt.

Figure 3. Mineral phase of reservoir silt.

Figure 4. Mineral phase of the unburned reservoir sludge at 120 ° C for 2 to 24 hours in a 5 M sodium hydroxide solution at 30 ° C.

Figure 5. Mineral phase of the unburned reservoir sludge in a hydrothermal treatment at 120 ° C for 6 to 24 hours in a 9 M sodium hydroxide solution at 30 ° C.

Figure 6. Mineral phase of 750 °C smoldering reservoir sludge at 120 °C hydrothermal treatment, 5 °C concentration of 5M sodium hydroxide solution for 6 to 24 hours.

Figure 7. The mineral phase of the 950 °C smoldering reservoir sludge at 120 ° C for 2 to 24 hours in a 5 M sodium hydroxide solution at 30 ° C.

Figure 8. Hydrothermal treatment at 150 ° C in a non-burned reservoir sludge at a concentration of 30 ° C Mineral phase in 1M sodium hydroxide solution for 6 to 24 hours.

Figure 9. Mineral phase of the unburned reservoir sludge in a hydrothermal treatment at 150 ° C for 6 to 24 hours in a 5 M sodium hydroxide solution at 30 ° C.

Figure 10. Mineral phase of the unburned reservoir sludge in a hydrothermal treatment at 150 ° C for 6 to 24 hours in a 9 M sodium hydroxide solution at 30 ° C.

Figure 11. Mineral phase of 750 °C smoldering reservoir sludge at 150 °C hydrothermal treatment, 5 °C concentration of 5M sodium hydroxide solution for 6 to 24 hours.

Figure 12. Mineral phase of 750 °C simmered reservoir sludge at 150 °C hydrothermal treatment, 30 ° C concentration 9M sodium hydroxide solution for 6 to 24 hours.

Figure 13. Mineral phase of 950 °C simmered reservoir sludge at 150 ° C hydrothermal treatment, 30 ° C concentration of 1 M sodium hydroxide solution for 6 to 24 hours.

Figure 14. Mineral phase of 950 °C smoldering reservoir sludge at 150 ° C hydrothermal treatment, concentration of 5 ° sodium hydroxide solution at 30 ° C for 6 to 24 hours.

Figure 15. Mineral phase of 950 °C smoldering reservoir sludge at 150 ° C hydrothermal treatment, concentration of 9 ° sodium hydroxide solution at 30 ° C for 6 to 24 hours.

Figure 16. Mineral phase of a non-tanked reservoir sludge at a hydrothermal treatment at 90 °C for 6 to 24 hours in a 5M sodium hydroxide solution at 30 °C.

Figure 17. Mineral phase of the unburned reservoir sludge at 120 ° C for 2 to 24 hours in a 5 M sodium hydroxide solution at 30 ° C.

Figure 18. Mineral phase of a non-tanked reservoir sludge at 150 °C hydrothermal treatment, 5 ° C solution at 30 ° C for 6 to 24 hours.

Figure 19. Mineral phase of 750 °C simmered reservoir sludge at 120 °C hydrothermal treatment, 5 °C concentration of 5M sodium hydroxide solution for 6 to 24 hours.

Figure 20. Mineral phase of 750 °C simmered reservoir sludge at 150 ° C hydrothermal treatment, 30 ° C concentration 5M sodium hydroxide solution for 6 to 24 hours.

Figure 21. Mineral phase of 950 °C simmered reservoir sludge at 90 °C hydrothermal treatment, 5 °C concentration of 5M sodium hydroxide solution for 6 to 24 hours.

Figure 22. Mineral phase of 950 °C smoldering reservoir sludge at 120 °C hydrothermal treatment, concentration of 5M sodium hydroxide solution at 30 °C for 6 to 24 hours.

Figure 23. Mineral phase of the 950 °C smoldering reservoir sludge at 150 ° C hydrothermal treatment, 30 ° C concentration 5M sodium hydroxide solution for 6 to 24 hours.

Figure 24, (a) and (b) are diagrams showing the mineral crystal structure of the unsimmered reservoir sludge observed by scanning electron microscopy (SEM); (c) and (d) are observed by SEM at 750 °C. The mineral crystal structure diagram of the silt of the smoldering reservoir; (e) is the mineral crystal structure diagram of the reservoir sludge sintered at 950 °C under SEM observation.

Figure 25, (a) to (d) is a 9M sodium hydroxide solution at a temperature of 120 ° C and 30 ° C at a temperature of 120 ° C and a reaction of 24 hours under a scanning electron microscope (SEM). The crystal structure of the later zeolite mineral oxymanganite.

Figure 26, (a) and (b) are observed by scanning electron microscope (SEM), The crystal structure of the zeolite mineral faujasite after 750 ° C smoldering reservoir sludge at a hydrothermal temperature of 150 ° C, 30 ° C concentration of 9 M sodium hydroxide solution and reaction for 24 hours.

27, (a) and (b) are observed by a scanning electron microscope (SEM). The sludge at 950 ° C is burned at a hydrothermal temperature of 150. The crystal structure of the zeolite mineral hydroxyhydrocarbazite after concentration of 9 M sodium hydroxide solution at a concentration of 30 ° C and a reaction time of 24 hours.

Figure 28, observed by scanning electron microscopy (SEM), after 950 ° C The crystal structure of the burned reservoir sludge at a temperature of 150 ° C and 30 ° C at a concentration of 9 M sodium hydroxide solution under different reaction time conditions, (a) and (b) are reaction time of 6 hours, in which no zeolite minerals are formed. (c) and (d) are reaction time of 12 hours, in which zeolite mineral hydroxide sodalite and calcium oxyhydronaphthalene are formed; (e) and (f) are reaction time 24 hours, and oxysodium sulphate is dissolved, The precipitated hydrogen oxyhydrogenite is formed from the surface of the oxyhydrogen soda.

Fig. 29 is a statistical analysis diagram of the adsorption capacity of zeolite powder and natural zeolite which have not been calcined, calcined at 750 ° C and calcined at 950 ° C.

Figure 30 is a graph showing the exchange capacity of cations of zeolite powder which has not been calcined, calcined at 750 ° C, and calcined at 950 ° C.

Figure 31 is a schematic view of a tubular and columnar shape of an amorphous zeolite block.

Figure 32. Mineral phase of an amorphous zeolite block.

Figure 33. Mineral phase of the amorphous zeolite block at a mixing ratio of 1:10 in the reservoir sludge and metakaolin.

The following examples are presented to illustrate and not to limit the various aspects and features of the invention.

(1) Experimental materials and methods:

(1) Reservoir silt: sludge collected from the sedimentation tank of Shimen Reservoir in Taiwan.

(2) Particle size distribution analyzer (PSD): The particle size analysis was carried out by a laser particle size analyzer (Shimadzu SALD-2001) to understand the distribution of the sludge of the reservoir and the size distribution of the sludge passing through the 100 mesh sieve. First, take an appropriate amount of reservoir sludge to disperse it evenly in deionized water, and then disperse the agglomerated sludge by ultrasonic shock for 30 minutes, then take a proper amount of solution and drop it into the laser particle size analyzer clock. After analysis, the sludge can be obtained. Particle size distribution map.

(3) X-ray Diffraction meter (XRD): The operating conditions of the X-ray powder diffraction analyzer (DX-2500) are: accelerating voltage 40kV and current 30mA, with CuKα(λ=1.50469 Å) is the incident light, and then the signal obtained by the graphite single-frequency filter is absorbed, the scanning speed is 0.04°/sec, and the diffraction angle range is 2θ=5°~65°. The phase identification was checked against the crystal phase diffraction angle recorded by the JCPD card.

(4) Scanning Electron Microscope (SEM): In order to confirm the influence of different experimental parameters on the microstructure of the zeolite, this experiment uses a field emission type scanning electron microscope (Model: Hitachi TM-1000, into a large nanometer) Research Center) Observed the change in particle size and microstructure of the zeolite powder after hydrothermal synthesis (grain shape). The analysis method is to flatten a small amount of zeolite powder sample on the carbon tape adhered to the conductive stage, and finally deposit platinum (Pt) on the surface of the sample for analysis.

(5) Hydrothermal method: means dissolving the reactants in a confined space under conditions of high temperature and high pressure. The process of resolution, that is, the volumetric percentage of a closed reaction vessel and the pressure generated by the temperature, constitutes a suitable reaction condition. The principle is as follows: after the solution in the autoclave is heated, on one hand, it vaporizes into steam, on the other hand, the volume also expands, causing the pressure to rise, and the volume of the solution at the reaction temperature is the percentage of the volume of the solution at room temperature. Decide. The hydrothermal kettle container of the present invention is made of a Teflon container as a lining for placing the reactants as a closed space, and the outer lining is a stainless steel outer casing, which can effectively close the reaction system and make the Teflon It is lined with a confined space that is stable under high temperature and high pressure.

(6) Hydrothermal process heating device: using hot air circulation oven (dengyng DO60) As a heating device, the temperature range is between 50 ° C and 300 ° C. The target temperature is set in advance. When the inside of the oven reaches the target temperature, the hydrothermal kettle is placed on the internal scaffold. After the heating time is over, the hydrothermal kettle is taken out. Allow it to cool naturally at room temperature.

(7) Ultrasonic homogenizer: When the solid powder is added to the liquid, ultrasonic homogenization is used. The machine is stirred to uniformly disperse the powder in the liquid, which can reduce the coagulation effect of the powder and enlarge the contact area between the powder and the liquid, so that the subsequent chemical reaction can be more completely uniform.

(8) Grouting or extrusion: refers to the mixing of sludge from the reservoir with the hot alkaline solution. The alkaline mixture obtained afterwards is filled in a mold (grouting) or subjected to pressure (extrusion) to impart a shape to the alkaline mixture.

(9) Block thermal hardening: refers to the mixing of sludge from the reservoir with the hot alkaline solution. The obtained alkaline mixture has a basic strength due to a certain temperature, mainly because the cerium hydroxide and the aluminum hydroxide in the alkaline mixture are subjected to a condensation reaction by temperature to form a bond, which enhances the strength of the block.

(10) Maintenance treatment: means that the formed alkaline mixture block is placed in a closed In the reaction tank, the block is subjected to steam in the tank to convert the mineral species in the block into zeolite minerals.

(11) Simmering treatment: means removing organic matter at high temperature and improving reaction activity Sexual temperature treatment.

(2) Experimental process:

The process for preparing zeolite by using the reservoir sludge can be divided into two processes of preparing zeolite powder and amorphous zeolite (Fig. 1), and the respective process steps are as follows:

(1) Preparation process of zeolite powder: (i) The invention is carried out in a reservoir sludge which is not calcined, simmered at 750 ° C, and simmered at 950 ° C, wherein the moisture content of the sludge of the unburned reservoir is 25 to 30%. Between the two, it can be directly mixed with the hot alkaline solution (hot lye) without a partial dehydration step; if the water content of the unburned reservoir sludge is higher than 45%, a partial dehydration step is required to The amount of sludge and water is reduced to 25%, and then mixed with the hot alkaline solution; in addition, the silt of the smoldering reservoir is ground and sieved and then mixed with the hot alkaline solution (hot lye); (ii) the above reservoir The sludge is mixed with a hot alkaline solution, that is, an aqueous sodium hydroxide solution at a solid-liquid ratio of 2 g/20 ml. The concentration of the solution is 1 M, 5 M, and 9 M, and the mixture is homogenized by an ultrasonic homogenizer during mixing, and the hot alkali solution is mixed. The temperature is controlled at 30 ° C; (iii) the treated reservoir sludge is hydrothermally treated at 90 ° C, 120 ° C and 150 ° C, respectively, and the reaction time is 6 hours, 12 hours and 24 hours; (iv) after hydrothermal treatment Reservoir silt, the silt has been formed from zeolite minerals to remove water To wash the sludge pH value of 9, the sludge dried at 100 deg.] C was pulverized, and after a 30 mesh screen, to obtain the zeolite powder.

(2) Preparation process of amorphous zeolite: (i) Reservoir sludge with a moisture content of about 28% And kaolin, that is, kaolin treated at 750 ° C, at a ratio of 3:2 by weight and 1:4 by weight, mixed in different proportions; (ii) mixing the mixture of the above two groups with a concentration of 10M, The hot alkaline solution at a temperature of 30 ° C is stirred and mixed into an alkaline mixture, and the weight ratio of the two groups of the mixture to the hot alkaline solution is 3:2; (ii) the two groups of the alkaline mixture are further grouted or extruded. The columnar and tubular samples were prepared in the manner; (iv) the samples were further subjected to a block thermosetting reaction at 30 ° C for 30 minutes; (v) followed by a curing treatment at 180 ° C for 24 hours to prepare a zeolite block.

(3) Experimental results:

(1) Analysis of reservoir silt properties: The reservoir silt is collected from Shimen Reservoir in Taiwan. The silt moisture content is about 28%, and the thermal burn loss is about 5.57%. Before the property analysis, it is sealed and sealed before use. The reservoir sludge should be placed in an oven, dried at 120 ° C, ground and crushed and passed through a 100 mesh sieve, and then subjected to force diameter analysis, chemical composition analysis and identification of crystalline mineral phases. The composition of the sludge in the Shimen Reservoir was analyzed by X-ray fluorescence analyzer (XRF). The main chemical components are shown in Table 1. Among them, cerium oxide is 61.4 wt%, alumina is 22.7 wt%, and the reservoir sludge is 矽The ear ratio is 2.30. The laser particle size analysis (PSD) of the sludge has an average particle size (D50) of about 2 (Fig. 2). After the powder is dried and ground, the mineral phase is analyzed by a diffractometer (XRD). The main mineral phase is quartz. (Quartz) phase, other mineral phases are Clinochlore, Albite and Muscovite (Fig. 3), in which the quartz phase is the main source of the lanthanum element, while the albite Phase and muscovite are sources of aluminum.

Table 1. Chemical composition of silt in Shimen Reservoir

(2) Process analysis of zeolite powder:

The invention separately discusses the influence on the type of zeolite powder generated from the reservoir sludge by the steps of calcination treatment, hot alkaline solution mixing and hydrothermal treatment.

(a) Effect of calcination on synthetic zeolite powder

The invention compares the reservoir sludge without simmering treatment, 750 ° C simmering treatment and 950 ° C treatment. The sludges of the three different treatments were treated under the same hot alkaline solution and hydrothermal reaction conditions (sodium hydroxide concentration of 5M at 30 °C, hydrothermal temperature of 120 °C), and it was found that the uncalculated sludge was free of zeolite mineral under these conditions. The phase was formed (Fig. 4), but the formation of hydroxysodalite was observed at a sodium hydroxide concentration of 9 M (Fig. 5). The sludge which was calcined at 750 ° C was formed at a sodium hydroxide concentration of 5 M, that is, a hydrolyzed soda of zeolite mineral ( FIG. 6 ). The 950 ° C smoldering sludge was also produced at a concentration of 5 M sodium hydroxide, also with the hydrolyzed hydrated zeolite (Figure 7).

From the above results, it can be inferred that the reservoir sludge destroys the raw material powder particles by calcination, so that the glass phase increases, so that the chemical activity increases, the zeolite synthesis time is shortened, and at the same time, the original mineral phase of the reservoir sludge itself, such as quartz and oblique magnesium green mud Stone, muscovite or plagioclase The structure is destroyed, and under the same temperature conditions, the zeolite mineral can be synthesized by using a lower concentration of sodium hydroxide solution through the calcined sludge.

(b) Effect of lye concentration on synthetic zeolite powder

The reservoir sludge without smoldering treatment reacted at a hydrothermal temperature of 150 ° C at a concentration of 1 M, 5 M and 9 M of sodium hydroxide solution respectively. No zeolite mineral phase was formed at a sodium hydroxide concentration of 1 M. The mineral phase composition was observed at 24 hours. There is no significant change in the composition of the original reservoir sludge (Figure 8). When the sodium hydroxide concentration was raised to 5 M, the zeolite mineral hydroxysodalite appeared (Fig. 9). When the concentration of sodium hydroxide reaches 9M, the shale minerals of zebolite and faujacite are formed. As the reaction time increases, all the original mineral phases of the reservoir sludge are obviously reduced, that is, the original minerals in the reaction process. Continuous dissolution provides a stable source of yttrium aluminum, so the hydrated sodalite and faujasite of the zeolite minerals have been steadily growing (Fig. 10).

The reservoir sludge treated at 750 °C was reacted at a hydrothermal temperature of 150 ° C with a concentration of 5 M and 9 M of sodium hydroxide solution. The original mineral phase of albite (Litite) and chlorite chlorite (Clinochlore) reached a concentration of sodium hydroxide. At 5 M, it almost completely dissolved at the beginning of the reaction time, which led to the appearance of zeolite mineral oxysoda and faujasite, and the quartz (Quartz) was also significantly reduced at the end of the reaction (Fig. 11). When the concentration of sodium hydroxide was increased to 9M, no zeolite minerals appeared in the initial stage of the reaction (6 hours). In the middle of the reaction (12 hours), the oxyhydrogen sodaite and faujasite of the zeolite mineral appeared to the reaction. The original mineral phase of the sludge at the end of the reservoir has disappeared (Figure 12).

The reservoir sludge treated at 950 °C is reacted at a hydrothermal temperature of 150 ° C with a concentration of sodium hydroxide aqueous solution of 1 M, 5 M and 9 M. Below the sodium hydroxide concentration of 5 M, the original mineral albite (Albite) and oblique magnesium green of the reservoir sludge Clinochlore dissolves in the initial stage of the reaction. It disappeared, and the zeolite mineral P-type zeolite (Zeolite P) was formed at the end of the reaction (24 hours) at a sodium hydroxide concentration of 1 M (Fig. 13), and at the initial stage (6 hours) at a sodium hydroxide concentration of 5 M (Fig. 14). . When the concentration of sodium hydroxide reached 9M, the reaction process was the same as that of the sludge treated at 750 °C. In the initial stage of the reaction (6 hours), the original mineral sodium feldspar and sillimanite disappeared but no zeolite minerals formed, in the medium term (12 hours). Zeolite mineral soda sulphate and cancrinite formation began (Fig. 15).

(c) Effect of hydrothermal temperature on synthesis of zeolite powder

The reservoir sludge without smoldering treatment was compared in the experimental conditions of sodium hydroxide aqueous solution concentration 5M, hydrothermal temperature 90 ° C, 120 ° C and 150 ° C. It was found that due to the tenacious structure of the original mineral phase of the reservoir sludge, sodium hydroxide of 5M sodium hydroxide solution could not effectively dissolve the original minerals at 90 °C and 120 °C hydrothermal temperature, so that no zeolite was produced (Fig. 16 and Fig. 17) until the water was hot. The temperature is raised to 150 ° C, and the high temperature promotes the solubility. At the beginning of the reaction (6 hours), the zeolite minerals are produced by Sodalite, but at the end of the reaction (24 hours), the mineral phase composition and the initial stage of the reaction (6 Hour) is similar, indicating that the overall response is initially completed (Figure 18).

The reservoir sludge treated at 750 °C was compared in the experimental conditions of sodium hydroxide aqueous solution concentration 5M, hydrothermal temperature 120 °C and 150 °C. At the initial stage of the hydrothermal temperature of 120 ° C (6 hours), the original mineral phase oblique magnesium chlorite phase of the reservoir sludge has been dissolved to provide strontium aluminum ions, and the oxyhydrogen sodaite of the zeolite mineral grows with time (Fig. 19). The temperature is raised to 150 ° C, the two-phase zeolite mineral hydroxy sodalite and faujasite (Figure 20), which shows that high temperature promotes the activity of sodium hydroxide, so the system's strontium aluminum ion content is different from 120 ° C , which leads to the phenomenon of symbiosis between the two phases.

The reservoir sludge treated at 950 °C is 5M in sodium hydroxide aqueous solution, water heat The experimental conditions of temperature 90 ° C, 120 ° C and 150 ° C were compared. After 950 °C smoldering reservoir sludge, the raw material powder is finer. Therefore, at the initial stage of the reaction (6 hours) at the hydrothermal temperature of 90 °C, there is a slight amount of zeolite mineral oxysoda soda, but not at the end of the reaction (24 hours). Continue to grow (Figure 21). At a hydrothermal temperature of 120 ° C, the zeolite mineral oxyamphetite was slightly crystallized at the beginning of the reaction (6 hours) until the end of the reaction (24 hours) continued to grow (Figure 22). When the hydrothermal temperature is 150 °C, the high temperature promotes the change of the lanthanum concentration of the system, and the zeolite mineral faujacite is formed. The phase composition of the initial reaction (6 hours) is similar to the end of the reaction (24 hours), and the overall reaction is presumed to be in the initial stage. The reaction is completed (Figure 23).

According to the above experiments (a) to (c), the conditions for the formation of various types of zeolite powder are shown in Table 2:

(d) SEM microstructural observation

The SEM was used to observe the reservoir sludge which was not simmered, simmered at 750 °C and simmered at 950 °C. The original mineral phase structure of the unsalted reservoir sludge was obvious (Fig. 24a and Fig. 24b), and the powder particles were simmered at 750 °C. Apparently showing a broken small block (Fig. 24c and Fig. 24d), when the calcination temperature reaches 950 °C, the powder particles in the sludge exhibit many irregular fracture surfaces and micropores, indicating that the sludge can be subjected to the calcination process. The crushing of the powder particles causes the specific surface area to increase the reactivity (Fig. 24e).

Under different experimental conditions, the present invention can integrate the conditions of the single phase zeolite, as shown in Table 2, at a calcining temperature of 950 ° C, a hydrothermal temperature of 120 ° C, a sodium hydroxide concentration of 9 M and a reaction time of 24 hours. A single zeolite mineral phase oxysodalite can be obtained, which can be obtained by SEM and has a spherical shape with an average size of 4 μm (Fig. 25). At a calcining temperature of 750 ° C, a hydrothermal temperature of 150 ° C, a sodium hydroxide concentration of 9 M and a reaction time of 24 hours, a single zeolite mineral phase faujasite can be combined, and its shape is a rectangular column with a length of about 7 to 8 μm. 26). In the sinter temperature of 950 ° C, hydrothermal temperature of 150 ° C, sodium hydroxide concentration of 9 M and reaction time of 24 hours, a single zeolite mineral phase hydrogen oxyhydrogenite can be combined, as shown in the figure, Radiation grows outward from the surface of the particle, and its shape is short needle-like (Fig. 27).

The invention finds that the zeolite mineral is synthesized under the experimental conditions of the water temperature of 150 ° C and the sodium hydroxide concentration of 9 M by the sludge at 950 ° C. The formation of zeolite minerals has not been observed at the reaction time of 6 hours, which should be the sludge powder. The dissolved sodium hydroxide solution has not reached saturation, and the dissolution rate is higher than the precipitation rate, so there is no reaction (Fig. 28a and Fig. 28b); when the reaction time reaches 12 hours, the zeolite mineral oxysoda and the hydrated nepheline are produced. The oxyhydrogen sodaite is in the form of a sphere, while the calcium oxyhydrocarbazite is in the form of a long strip (Fig. 28c and Fig. 28d); when the reaction time is up to 24 hours, there are many fine strips of hydroxyazeite agglomerated, and The amount of spherical oxyhydrogen soda shale is significantly reduced. It should be the oxysodium sulphate formed during the reaction time of 12 hours. Because the alkalinity of the solution is too high, the hydrothermal temperature is enough to provide enough energy to re-dissolve it, which in turn causes another The zeolitic mineral hydrated hydrated nepheline precipitated on the surface of the oxyhydrogen soda spheroidal type. Because of the agglomeration of hydrated hydrated hydrate, it is smaller than the hydrogen oxyhydrocarbazite formed in 12 hours, and the length is about 2 μm. 28e and Figure 28f).

(e) Ammonia nitrogen test

In the ammonia nitrogen adsorption experiment, about 0.5 g of zeolite powder was impregnated into a 46.5 mg/L aqueous solution of ammonium nitrate, measured every two hours before 12 hours, and then observed at 24 hours and 48 hours, and the experimental samples were three: The sludge of the unburned reservoir is hydrolyzed at a temperature of 150 ° C and 30 ° C with a sodium hydroxide concentration of 9 M, and the zeolite powder and the reservoir sludge are reacted at 750 ° C for 24 hours, and the hydrothermal temperature is 150 ° C, 30 ° C of hydrogen peroxide. The sodium concentration was 9 M, and the zeolite powder and the reservoir sludge which were reacted for 24 hours were calcined at 950 ° C, the hydrothermal temperature was 150 ° C, and the sodium hydroxide concentration at 30 ° C was 9 M, and the reaction was carried out for 24 hours. The experimental results show that the ion exchange capacity of the zeolite powder at 950 ° C is higher than that of the other two groups (zeolite powder of 950 ° C: 21.23 cmol / kg; zeolite powder of 750 ° C: 11.12 cmol / kg; zeolite powder of unburned sludge: 10.44) Cmol/kg), speculated that the zeolite mineral phase hydrogen oxyhydrogenite is The oxynitronite dissolves and precipitates, so the mineral phase is finer and has a larger surface area contact reaction and thus has a higher ion exchange capacity. The three groups of sludge adsorption rate grew at a fast rate in 24 hours and slowly grew after 24 hours. Generally, the natural zeolite mineral has a maximum adsorption property of about 5.5 cmol/kg, and the 950 ° C calcined sludge has a value of 4.23 cmol/kg, which is four times higher than natural minerals (Fig. 29).

In the cation exchange, about 1g of zeolite powder is impregnated in 50ml of 43% ammonia water for 24 hours, and the zeolite powder impregnated with ammonia water for 24 hours is filtered and dried by deionized water, and then placed in 3M, 100ml. The cation exchange was again carried out in the NaCl solution, and the replacement condition was recorded. The adsorption curves of the three groups of sludges all showed a growth before saturation, and the zeolite which was not saturated with the calcined zeolite powder was saturated at 750 ° C and 950 ° C for 10 hours. The powder was saturated at 12 hours, and the exchange rate was about one step apart from the adsorption experiment. It is presumed that the zeolite phase has a mineral phase with a small pore size of zeolite minerals (oxygen sodalite and hydroxyazeite). Therefore, Nh ⁺ ions with a small ionic radius are relatively stable in destructuring, so that Na ⁺ ions are easily desorbed, and Nh ⁺ ions are allowed to enter the structure. The zeolite powder which has been calcined at 950 °C has a relatively low exchange rate of the zeolite mineral powder, and it is presumed that the main phase of the zeolite mineral is hydrated calcium hydrate, and its destructive pores are smaller than that of oxysoda. It is easier to capture NH ⁺ ions, but its structure is not easily exchanged by Na ⁺ ion exchange (Figure 30).

(3) Analysis of the results of amorphous zeolite blocks:

(a) Analysis of zeolite mineral composition of amorphous zeolite blocks

The appearance of the tubular and columnar zeolite blocks is an iron red block (Fig. 31). According to the results of the X-ray diffractometer, the original mineral phase in the reservoir sludge and the metakaolin has disappeared, and the synthesized zeolite is the oblique calcium zeolite. , the oblique calcium zeolite is one of the groups of analcites, and the zeolite block is pure phase Block of chalcedony zeolite (Figure 32).

(b) Comparison of the amount of metakaolin added

The mixture of reservoir sludge and metakaolin is 1:4, the mineral phase is identified as type A zeolite (Fig. 33), and the reservoir sludge and metakaolin are added in a ratio of 3:2. The mineral phase is chalcedony. It is shown that the addition amount of the metakaolin increases the ratio of the lanthanum aluminum element to be the same, and it is easy to form the type A zeolite.

Claims (25)

A method of preparing a zeolite comprising the steps of: (a) providing an aqueous sludge comprising a mineral having alumina and a mineral having cerium oxide; (b) treating the aqueous sludge by calcining; (c) The aqueous sludge is mixed with a hot alkaline solution to obtain an alkaline sludge; (d) hydrothermally treating the alkaline sludge to form a zeolite slurry; and (e) reducing the zeolite mud to the zeolite mud Treatment of the pH value of the material. The method for producing a zeolite according to claim 1, wherein the step (d) may further comprise the step of subjecting the zeolite slurry to a drying process and grinding into a powder. The method for producing a zeolite according to claim 2, wherein the drying treatment is carried out at a temperature ranging from 100 ° C to 150 ° C. The method for producing a zeolite according to claim 1, wherein the aqueous sludge has a water content ranging from 20% to 65%. The method for producing a zeolite according to claim 1, wherein the step (a) and (b) further comprises the step of reducing the water content of the aqueous sludge. The method for producing a zeolite according to claim 1, wherein the calcining method is carried out at a temperature ranging from 550 ° C to 1050 ° C. A method for preparing a zeolite as described in claim 1, wherein the method of treating the zeolite The subsequent aqueous sludge can be further subjected to a grinding and sieving step. The method for producing a zeolite according to claim 5, wherein the step of reducing the water content of the aqueous sludge means reducing the water content of the aqueous sludge to between 25% and 45%. The method for producing a zeolite according to claim 1, wherein the mixed weight ratio of the aqueous sludge to the hot alkaline solution ranges from 1:10 to 1:3. A method of producing a zeolite as described in claim 1, wherein the hot alkaline solution means a sodium hydroxide solution. The method for producing a zeolite according to claim 1, wherein the hot alkaline solution has a concentration ranging from 3 M to 15 M, and the hot alkaline solution has a temperature ranging from 30 ° C to 90 ° C. The method for producing a zeolite according to claim 1, wherein the hydrothermal treatment is carried out at a temperature ranging from 100 ° C to 250 ° C for a treatment time of from 6 to 24 hours. The method for preparing a zeolite according to claim 1, wherein the treatment for lowering the pH value of the zeolite slurry means that the zeolite slurry is washed with deionized water to make the zeolite slurry The pH value is (pH) to 8-10. The method for producing a zeolite according to claim 1, wherein the zeolite is selected from the group consisting of zeolite P (Zeolite P), faujasite, hydroxysodalite, and hydrated nepheline. (Hydroxycancrinite) group of groups. A method of preparing an amorphous zeolite block comprising the steps of: (a) providing a mixture comprising an aqueous mineral having alumina and a mineral having cerium oxide and a mixture of metakaolin, wherein the aqueous sludge is treated by calcination; (b) the mixture is combined with a hot alkaline solution Mixing is carried out to obtain an alkaline mixture; (c) the alkaline mixture is formed into a specific shape by molding; and (d) the alkaline mixture is subjected to a curing treatment. The method of preparing an amorphous zeolite block according to claim 15, wherein the step of treating the alkaline mixture by a block thermosetting method may further be included between the steps (c) and (d). The method for preparing an amorphous zeolite block according to claim 16, wherein the block thermosetting method is carried out at a temperature ranging from 20 ° C to 95 ° C, and the treatment time of the method is from 10 minutes to 8 hours. The method for preparing an amorphous zeolite block according to claim 15, wherein the metakaolin is obtained by treating kaolin with a high temperature between 550 ° C and 1000 ° C, and the mixed weight ratio range of the aqueous sludge and the metakaolin is obtained. It is 5:1 to 1:4. The method for preparing an amorphous zeolite block according to claim 15, wherein the mixture is mixed with the hot alkaline solution in a weight ratio ranging from 3:1 to 2:3. A method of preparing an amorphous zeolite block as described in claim 15 wherein the hot alkaline solution means a sodium hydroxide solution. The method for preparing an amorphous zeolite block according to claim 15, wherein the heat is The concentration of the alkaline solution ranges from 3 M to 15 M, and the temperature of the hot alkaline solution ranges from 30 ° C to 90 ° C. A method of preparing an amorphous zeolite block as described in claim 15 wherein the molding method refers to a slip casting method or an extrusion molding method. A method of preparing an amorphous zeolite block as described in claim 15 wherein the specific shape refers to a tubular shape, a honeycomb tubular shape, a column shape or a brick shape. The method for producing an amorphous zeolite block according to claim 15, wherein the curing treatment is carried out at a temperature ranging from 120 ° C to 250 ° C for a treatment time of 4 to 24 hours. The method for producing an amorphous zeolite block according to claim 15, wherein the amorphous zeolite block is selected from the group consisting of zeolite A (Zeolite A), zeolite P (Zeolite P), and oblique lime zeolite (Wairakite). Group of analcime and faujasite.