CN113307286A - Preparation method of fly ash-based W-type zeolite for slow-release fertilizer carrier - Google Patents
Preparation method of fly ash-based W-type zeolite for slow-release fertilizer carrier Download PDFInfo
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- CN113307286A CN113307286A CN202110756359.1A CN202110756359A CN113307286A CN 113307286 A CN113307286 A CN 113307286A CN 202110756359 A CN202110756359 A CN 202110756359A CN 113307286 A CN113307286 A CN 113307286A
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B39/00—Compounds having molecular sieve and base-exchange properties, e.g. crystalline zeolites; Their preparation; After-treatment, e.g. ion-exchange or dealumination
- C01B39/02—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof; Direct preparation thereof; Preparation thereof starting from a reaction mixture containing a crystalline zeolite of another type, or from preformed reactants; After-treatment thereof
- C01B39/46—Other types characterised by their X-ray diffraction pattern and their defined composition
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- C—CHEMISTRY; METALLURGY
- C05—FERTILISERS; MANUFACTURE THEREOF
- C05D—INORGANIC FERTILISERS NOT COVERED BY SUBCLASSES C05B, C05C; FERTILISERS PRODUCING CARBON DIOXIDE
- C05D1/00—Fertilisers containing potassium
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- C—CHEMISTRY; METALLURGY
- C05—FERTILISERS; MANUFACTURE THEREOF
- C05G—MIXTURES OF FERTILISERS COVERED INDIVIDUALLY BY DIFFERENT SUBCLASSES OF CLASS C05; MIXTURES OF ONE OR MORE FERTILISERS WITH MATERIALS NOT HAVING A SPECIFIC FERTILISING ACTIVITY, e.g. PESTICIDES, SOIL-CONDITIONERS, WETTING AGENTS; FERTILISERS CHARACTERISED BY THEIR FORM
- C05G3/00—Mixtures of one or more fertilisers with additives not having a specially fertilising activity
- C05G3/40—Mixtures of one or more fertilisers with additives not having a specially fertilising activity for affecting fertiliser dosage or release rate; for affecting solubility
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- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2002/00—Crystal-structural characteristics
- C01P2002/70—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data
- C01P2002/72—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data by d-values or two theta-values, e.g. as X-ray diagram
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2002/00—Crystal-structural characteristics
- C01P2002/80—Crystal-structural characteristics defined by measured data other than those specified in group C01P2002/70
- C01P2002/85—Crystal-structural characteristics defined by measured data other than those specified in group C01P2002/70 by XPS, EDX or EDAX data
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Abstract
The invention provides a preparation method of fly ash based zeolite W for a slow release fertilizer carrier, which comprises the following steps: (1) drying the fly ash, and grinding the fly ash to the fineness of primary fly ash to obtain pretreated fly ash; (2) preparing a potassium hydroxide solution with the concentration of 5 mol/L; (3) fully mixing and stirring the pretreated fly ash and the potassium hydroxide solution according to the liquid-solid ratio of 2L/kg; (4) and transferring the uniformly stirred liquid-solid mixture into a polytetrafluoroethylene high-pressure reaction kettle, crystallizing at 120-150 ℃ for 12-24 h, performing suction filtration and washing after crystallization is finished until the pH is 8-10, and drying and grinding a filter cake to obtain the fly ash-based zeolite W. The method adopts a one-step low-temperature hydrothermal method to convert the fly ash generated by the coal-fired power plant into the zeolite W, and has the characteristics of low raw material price, simple preparation process, relatively low energy consumption and easy industrial production, thereby not only realizing the resource utilization of the fly ash, but also effectively improving the utilization rate of the fertilizer as a slow-release fertilizer carrier.
Description
Technical Field
The invention belongs to the technical field of resource utilization of industrial solid wastes and zeolite synthesis, and particularly relates to a method for preparing W-type zeolite from coal ash of a coal-fired power plant.
Background
Chemical fertilizers are essential nutrients for modern agricultural production. The annual consumption of the fertilizer in China reaches more than 5000 ten thousand tons, but the utilization rate of the fertilizer nutrient is only about 35 percent. The loss of the effective components of the fertilizer not only causes economic loss of more than 1000 billion yuan per year, but also more importantly causes environmental pollution. In this context, slow release fertilizers have come into play. The slow release fertilizer is a novel value-added fertilizer in the low-carbon economic era and is also an important development direction of the fertilizer industry in the 21 st century. The slow release fertilizer is a trend of China and even the world to replace the traditional chemical fertilizer. The outline of the national medium-and-long-term scientific and technical development planning (2006-2020) lists the research and development of novel environment-friendly fertilizers, slow-release fertilizers and the like as a priority development theme. Therefore, the research and development of the novel slow release fertilizer have great significance for the agricultural development of China.
After the slow release fertilizer is applied to soil, the slow release of fertilizer nutrients can be controlled, the requirement on nutrients in the growth period of crops is met, the yield and the quality of the crops are improved, and the utilization rate of the fertilizer is obviously improved. The slow release fertilizer derives more directions in the continuous improvement and development process, and the development of the slow release fertilizer technology has advanced into a new era from chemical derivation and condensation technology to chemical coating and coating technology and then to the technology of selecting materials such as zeolite, activated carbon and the like which have more friendly adsorbability and ionicity to soil.
The slow release fertilizer in the current market has the problems of limited application, soil pollution and the like due to overhigh price and difficult degradation of a high polymer coating material. In addition, the fertilizer has the advantages of increasing the efficiency, the technical innovation and the agricultural and chemical service level, and is urgent in the current fertilizer market. Therefore, the development of the slow release fertilizer with low price and high and new technology has very important practical significance and potential economic value.
The fly ash is solid waste after coal combustion, the annual output of the fly ash is huge, and by 2021 years, the total stockpiling amount of the fly ash in China is estimated to exceed 20 hundred million tons. A large amount of fly ash is used as solid waste to be stacked or buried on site, so that not only is a large amount of land occupied, but also dust can be caused, and toxic chemical substances in the fly ash cause serious harm to the environment and human health. Therefore, the efficient development and utilization of the fly ash have very important significance.
The W-type zeolite is a K + type zeolite, has the same topological structure as barium cross zeolite (merlingite), has a lower framework silica-alumina ratio (1.67-2.4), has large framework electronegativity, achieves the theoretical adsorption capacity of the K + of 171.4mg/g, and has good hydrophilicity and water absorption capacity (0.56 mL/g). Based on the above situation, it is an important technical subject to design a preparation method of fly ash based W-type zeolite for slow release fertilizer carrier.
Disclosure of Invention
The invention aims to provide a fast and efficient process technology for preparing W-type zeolite by using fly ash, and the prepared W-type zeolite can be used as a carrier of a slow-release fertilizer for crop growth.
The technical scheme of the invention is as follows: a preparation method of fly ash based W-type zeolite for slow release fertilizer carrier is characterized by comprising the following steps: the method comprises the following steps:
the first step is as follows: and drying, grinding and sieving the fly ash to obtain the pretreated fly ash.
The second step is that: preparing 5mol/L potassium hydroxide solution.
The third step: the pretreated fly ash and the potassium hydroxide solution are fully mixed and stirred according to the liquid-solid ratio of 2L/kg.
The fourth step: and transferring the uniformly stirred liquid-solid mixture into a polytetrafluoroethylene high-pressure reaction kettle, crystallizing at 120-150 ℃ for 12-24 h, after crystallization is finished, carrying out vacuum filtration and washing until the pH value is 8-10, and drying and grinding a filter cake to obtain the fly ash-based W-type zeolite.
According to the technical scheme, the particle size of the pulverized fuel ash obtained after grinding and sieving in the first step is 0.2-1.0 mm.
According to the technical scheme, in the first step, the grinding mode is ball milling, the ball milling is carried out for 2-24 hours, and then the pretreated fly ash obtained after screening the fly ash is first-grade ash.
The invention has the following beneficial effects:
(1) the method takes the fly ash of the coal-fired power plant as the raw material, adopts a one-step low-temperature hydrothermal method to convert the fly ash generated by the coal-fired power plant into the W-type zeolite, has the characteristics of low raw material price, simple preparation process, relatively low energy consumption and easy industrial production, not only realizes the resource and high-value utilization of the fly ash, but also provides a novel carrier W-type zeolite carrier for the slow-release fertilizer, and effectively improves the utilization rate of the fertilizer.
(2) The conversion rate of the fly ash can reach 90%, the framework Si/Al molar ratio of the fly ash-based W-type zeolite is 1.7-2.1, the prepared fly ash-based W-type zeolite has good adsorption and cation exchange performances, the zeolite is used as a carrier of a slow release fertilizer, the release of nutrients in the fertilizer can be controlled, the utilization rate of the fertilizer is improved, and the fly ash-based W-type zeolite also has the effects of water retention and soil improvement after long-term large-scale use.
(3) The invention selects cheap and easily obtained raw materials (such as fly ash) to prepare the zeolite, greatly reduces the manufacturing cost, is beneficial to subsequent large-scale application in agricultural production, the prepared W-type zeolite rich in potassium ions can be used as a long-acting slow-release potash fertilizer for crop growth, and the W-type zeolite can be used as a compound slow-release compound fertilizer after being mixed with other fertilizers and applied to crop growth.
(4) The fly ash-based W-type zeolite is used as a slow-release potash fertilizer and has larger potassium ion adsorption capacity and longer potassium ion release period. The mass of potassium ions in every 1 kg of fly ash-based W-type zeolite is 105-150 g.
Drawings
FIG. 1 is an XRD pattern of fly ash from a thermal power plant in Gansu;
FIG. 2 is an XRD pattern of the fly ash based W-type zeolite prepared by the invention.
Detailed Description
The present invention will be described in further detail with reference to examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
In the following examples, the raw materials are fly ash, KOH and deionized water from coal-fired power plants. The fly ash comes from a certain thermal power plant in Gansu, and the main oxides of the fly ash comprise the following components in percentage by mass: the main oxides of the catalyst comprise the following components in percentage by mass: SiO 22(49)、Al2O3(20)、CaO(7.1)、MgO(2.5)、Na2O(0.9)、Fe2O3(4.9)、K2O(1.7)、SO3(1.6)、TiO2(0.9)、MnO(0.05)、P2O5(0.4) and others (10.95). . Potassium hydroxide (anhydrous) was analytically pure and purchased from Tianjin Daloco chemical reagent works. Deionized water is self-made in a laboratory. The fineness of the first-grade fly ash refers to that the sieve residue of a 45-um square-hole sieve is not more than 12 percent, namely the 45-um pass rate is 88 percent, and 45-um is equivalent to 325 meshes.
Example 1
The coal-fired power plant fly ash is dried for 2 hours at 120 ℃ and ground to the primary fly ash fineness to be used as pretreated fly ash. Accurately weighing 35g of pretreated fly ash and 5mol/L of potassium hydroxide solution according to the liquid-solid ratio of 2 mL: mixing 1g of the components in proportion, fully stirring for 0.5h, transferring the mixture to a polytetrafluoroethylene reaction kettle with the volume of 100ml, carrying out crystallization reaction for 24h in a constant-temperature air-blast drying oven at the temperature of 120 ℃, carrying out vacuum filtration and washing until the pH value is 8-10 after crystallization is finished, and grinding a filter cake to obtain the fly ash-based W-type zeolite. The mass of potassium ions in the fly ash-based W-type zeolite obtained by X-ray energy spectrum analysis (EDS) analysis was 125.63 mg/g.
Example 2
The coal-fired power plant fly ash is dried for 2 hours at 120 ℃ and ground to the primary fly ash fineness to be used as pretreated fly ash. Accurately weighing 35g of pretreated fly ash and 5mol/L of potassium hydroxide solution according to the liquid-solid ratio of 2 mL: mixing 1g of the components in proportion, fully stirring for 0.5h, transferring the mixture to a polytetrafluoroethylene reaction kettle with the volume of 100ml, carrying out crystallization reaction for 24h in a constant-temperature air-blast drying oven at the temperature of 150 ℃, carrying out vacuum filtration and washing until the pH value is 8-10 after crystallization is finished, and grinding a filter cake to obtain the fly ash-based W-type zeolite. The mass of potassium ions in the fly ash-based W-type zeolite obtained by X-ray energy spectrum analysis (EDS) analysis was 145.11 mg/g.
Example 3
The coal-fired power plant fly ash is dried for 2 hours at 120 ℃ and ground to the primary fly ash fineness to be used as pretreated fly ash. Accurately weighing 35g of pretreated fly ash and 5mol/L of potassium hydroxide solution according to the liquid-solid ratio of 2 mL: mixing 1g of the components in proportion, fully stirring for 0.5h, transferring to a polytetrafluoroethylene reaction kettle with the volume of 100ml, carrying out crystallization reaction for 12h in a constant-temperature air-blast drying oven at 150 ℃, carrying out vacuum filtration and washing until the pH value is 8-10 after crystallization, and grinding a filter cake to obtain the fly ash-based W-type zeolite. The mass of potassium ions in the fly ash-based W-type zeolite obtained by X-ray energy spectrum analysis (EDS) analysis was 108.63 mg/g.
Example 4
The coal-fired power plant fly ash is dried for 2 hours at 120 ℃ and ground to the primary fly ash fineness to be used as pretreated fly ash. Accurately weighing 35g of pretreated fly ash and 5mol/L of potassium hydroxide solution according to the liquid-solid ratio of 2 mL: mixing 1g of the components in proportion, fully stirring for 0.5h, transferring to a polytetrafluoroethylene reaction kettle with the volume of 100ml, carrying out crystallization reaction for 18h in a constant-temperature air-blast drying oven at 150 ℃, carrying out vacuum filtration and washing until the pH value is 8-10 after crystallization, and grinding a filter cake to obtain the fly ash-based W-type zeolite. The mass of potassium ions in the fly ash-based W-type zeolite obtained by X-ray energy spectrum analysis (EDS) analysis was 135.03 mg/g.
The method takes the fly ash of the coal-fired power plant as the raw material, adopts a one-step low-temperature hydrothermal method to convert the fly ash generated by the coal-fired power plant into the W-type zeolite, has the characteristics of low raw material price, simple preparation process, relatively low energy consumption and easy industrial production, not only realizes the resource and high-value utilization of the fly ash, but also provides a novel carrier W-type zeolite carrier for the slow-release fertilizer, and effectively improves the utilization rate of the fertilizer.
While the foregoing description shows and describes the preferred embodiments of the present invention, it is to be understood that the invention is not limited to the forms disclosed herein, but is not to be construed as excluding other embodiments and is capable of use in various other combinations, modifications, and environments and is capable of changes within the scope of the inventive concept as described herein, commensurate with the above teachings, or the skill or knowledge of the relevant art. And that modifications and variations may be effected by those skilled in the art without departing from the spirit and scope of the invention as defined by the appended claims.
Claims (3)
1. A preparation method of fly ash based W-type zeolite for slow release fertilizer carrier is characterized by comprising the following steps: the method comprises the following steps:
the first step is as follows: drying, grinding and sieving the fly ash to obtain pretreated fly ash;
the second step is that: preparing a potassium hydroxide solution with the concentration of 5 mol/L;
the third step: fully mixing and stirring the pretreated fly ash and the potassium hydroxide solution according to the liquid-solid ratio of 2L/kg;
the fourth step: and transferring the uniformly stirred liquid-solid mixture into a polytetrafluoroethylene high-pressure reaction kettle, crystallizing at 120-150 ℃ for 12-24 h, after crystallization is finished, carrying out vacuum filtration and washing until the pH value is 8-10, and drying and grinding a filter cake to obtain the fly ash-based W-type zeolite.
2. The method for preparing the fly ash-based W-type zeolite for slow release fertilizer carrier according to claim 1, characterized in that: the particle size of the pulverized fuel ash obtained after grinding and sieving in the first step is 0.2-1.0 mm.
3. The method for preparing the fly ash-based W-type zeolite for slow release fertilizer carrier according to claim 1, characterized by comprising the following steps: in the first step, the grinding mode is ball milling, the ball milling is carried out for 2-24 hours, and then the pretreated fly ash obtained after screening the fly ash is first-grade ash.
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Citations (6)
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| MX2009014260A (en) * | 2009-12-21 | 2011-06-21 | Ct Investig Y Estudios Del Ipn | Hydrothermal method for the direct synthesis of zeolites from fly ash. |
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| CN107814858A (en) * | 2017-10-18 | 2018-03-20 | 兰州石化职业技术学院 | A kind of preparation method of complex carrier polypropylene catalyst |
| AU2020100373A4 (en) * | 2019-04-25 | 2020-04-16 | Taiyuan University Of Technology | Method for preparing ssz-13 molecular sieve by using fly ash |
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2021
- 2021-07-05 CN CN202110756359.1A patent/CN113307286A/en active Pending
Patent Citations (6)
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| MX2009014260A (en) * | 2009-12-21 | 2011-06-21 | Ct Investig Y Estudios Del Ipn | Hydrothermal method for the direct synthesis of zeolites from fly ash. |
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| CN102557063A (en) * | 2012-01-16 | 2012-07-11 | 中国环境科学研究院 | Method for preparing molecular sieve by using power plant coal ash as raw materials and molecular sieve |
| CN103553067A (en) * | 2013-11-19 | 2014-02-05 | 河北工业大学 | Method for producing total-potassium W-type molecular sieve by utilizing KOH alkali-activated potassium feldspar |
| CN107814858A (en) * | 2017-10-18 | 2018-03-20 | 兰州石化职业技术学院 | A kind of preparation method of complex carrier polypropylene catalyst |
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Non-Patent Citations (3)
| Title |
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| HERALDY, E, ET AL: "Effect of kalium hydroxide/fly ash ratio and hydrothermal temperature in Zeolite W formation by X-ray diffraction analysis", 《IOP CONFERENCE SERIES-MATERIALS SCIENCE AND ENGINEERING》 * |
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