A zeolite based on municipal solid waste incineration fly ash, its preparation method and application

Abstract

The present invention discloses a preparation method of zeolite based on municipal solid waste incineration fly ash, which comprises the following steps: pickling and removing impurities from the municipal solid waste incineration fly ash and then washing it with water; adding a mixture of FeCl3 and FeSO4 to the washed and dried municipal solid waste incineration fly ash, mixing it with an alkali solution, and putting it into a ball mill tank together with grinding balls for mechanical chemical reaction. While ball milling, heat the reaction materials to prepare zeolite; the mass ratio of FeSO4 to FeCl3 in the mixture is (5-6):1, and the mass ratio of the washed fly ash to the above mixture is (5-10):1. This method removes most of the impurities in the fly ash through pickling, increases the silicon-aluminum ratio, improves the purity of the synthesized zeolite, and modifies the zeolite during the mechanochemical synthesis process, not only saving a large amount of preparation time, but also improving the adsorption performance of the zeolite.

Description

Technical Field

[0001] The present invention belongs to the technical field of high-value utilization of municipal solid waste incineration fly ash, and specifically relates to a zeolite based on municipal solid waste incineration fly ash, a preparation method thereof, and an application thereof. Background Art

[0002] With the improvement of the urbanization rate, the generation amount of solid waste such as municipal solid waste has increased year by year, restricting economic development and threatening the living environment of people. Nearly 80% of municipal solid waste is harmlessly treated by incineration. However, a large amount of municipal solid waste incineration fly ash is generated during incineration. At present, the main disposal method of municipal solid waste incineration fly ash is landfill, and there are great difficulties in resource utilization.

[0003] Municipal solid waste incineration fly ash is dark white or dark gray, with a particle size in the micron range, in the shape of rods, polygons, and spheres, having a high porosity and a large specific surface area, and relatively high contents of CaO and Cl. It can be used as a solid additive for the production of cement and concrete, and can also be used for the hydrothermal synthesis of zeolite. Zeolite is a crystalline aluminosilicate composed of exchangeable metal cations [SiO4] 4- and [AlO4] 5- and has a tetrahedral, three-dimensional network structure and a rich pore structure. Zeolite has excellent surface area and pore structure properties, strong adsorption capacity, high cation exchange capacity (CEC), and good hydrothermal stability. Therefore, it is widely used in environmental and industrial fields, including new fields such as adsorbents, catalysts, ion exchangers, and antibacterial materials. With the increasing demand for the performance and quantity of zeolite products, natural zeolite can no longer meet the demand, and a synthetic method with low cost, low energy consumption, and high purity is required.

[0004] At present, the synthetic methods for synthesizing zeolite using municipal solid waste incineration fly ash include the Chinese patent: Publication No. CN116651388A, "A Method for Converting Municipal Solid Waste Incineration Fly Ash into a Zeolite Adsorption Material, Its Product and Application", which uses polyaluminum flocculant, red mud, and municipal solid waste incineration fly ash as raw materials. After stirring and mixing evenly, it is introduced into a supercritical water reactor. After solid-liquid separation, activated polyaluminum fly ash gel is obtained. Then, sodium silicate, polymeric aluminum ferric phosphate, and the gel are stirred, and cured under natural conditions for 3 - 15 days to obtain a zeolite adsorption material. Although this method has simple steps, the preparation period is too long, the energy consumption during the preparation process is high, and the economy is poor. Summary of the Invention

[0005] In order to solve at least one of the above problems, the present invention provides a zeolite based on municipal solid waste incineration fly ash, a preparation method thereof, and an application thereof.

[0006] In order to achieve the above object, the present invention adopts the following technical means:

[0007] The first aspect of the present invention provides a method for preparing zeolite based on municipal solid waste incineration fly ash, comprising the following steps:

[0008] (1) Pickle and remove impurities from the municipal solid waste incineration fly ash and then wash it with water; in some embodiments of the present invention, deionized water filtration is used for washing and impurity removal;

[0009] (2) Add a mixture of FeCl3 and FeSO4 to the dried fly ash washed with water, mix it with an alkali solution, and put it into a ball mill together with grinding balls for mechanical chemical reaction. Heat the reaction materials while ball milling to prepare zeolite;

[0010] In step (2), the mass ratio of FeSO4 to FeCl3 in the mixture is (5-6):1, and the mass ratio of the fly ash obtained by washing to the above mixture is (5-10):1. In a preferred embodiment of the present invention, the mass ratio of FeSO4 to FeCl3 in the mixture is 5.5:1.

[0011] In some embodiments of the present invention, the concentration of the alkali solution is 2-4 mol / L, and the liquid-solid mass ratio of the alkali solution to the fly ash is (3-5):1.

[0012] In some embodiments of the present invention, the acid used for pickling and impurity removal is one of acetic acid, propionic acid, butyric acid, succinic acid, and lactic acid; the concentration of the acid is 0.2-1 mol / L.

[0013] In some embodiments of the present invention, during the pickling and impurity removal process, the mass ratio of the acid to the fly ash is (2-5):1, and the stirring time during pickling is 3-5 h.

[0014] In some embodiments of the present invention, the silicon-aluminum mass ratio in the municipal solid waste incineration fly ash is (1.1-1.5):1.

[0015] In some embodiments of the present invention, before pickling and impurity removal of the municipal solid waste incineration fly ash in step (1), it is calcined and activated at a temperature of 650-750 °C.

[0016] In some embodiments of the present invention, in the ball mill, the ratio of the grinding balls to the solid mass is (10-20):1, the rotation speed of the ball mill is 300-700 r / min, and the ball milling time is 2-10 hours.

[0017] In some embodiments of the present invention, the ball mill is a high-temperature ball mill, and the temperature inside the ball mill is maintained at 100-300 °C.

[0018] The second aspect of the present invention provides a zeolite prepared by the method described in the first aspect.

[0019] The third aspect of the present invention provides an application of the zeolite described in the second aspect in the efficient adsorption of heavy metals: copper, mercury, cesium, and ammonia nitrogen in a liquid.

[0020] Advantages of the present invention

[0021] Compared with the prior art, the present invention has the following advantages: The present invention uses waste incineration fly ash to prepare zeolite, disposes of the waste incineration fly ash, realizes the high-value utilization of the waste incineration fly ash, replaces the landfill of waste incineration ash that occupies a large amount of land, and reduces environmental pollution.

[0022] Before synthesis, most of the impurities are removed by pickling in the present invention, which increases the silicon-aluminum ratio and helps to improve the purity of the synthesized zeolite. During the synthesis process, the mechanochemical method is used to accelerate the reaction, and the zeolite is modified, which not only saves a large amount of preparation time but also improves the adsorption performance of the zeolite. The zeolite prepared by the method described in the present invention is magnetic zeolite, which is convenient for separation and recovery from the treatment object after adsorbing pollutants. At the same time, the zeolite has good reusability and can be applied to the efficient adsorption of heavy metals: copper, mercury, cesium, and ammonia nitrogen in a liquid. Description of the drawings

[0023] Figure 1 The process flow diagram of preparing zeolite from waste incineration fly ash according to the present invention is shown. Specific embodiments

[0024] The following examples are used here to demonstrate the preferred embodiments of the present invention. Those skilled in the art will understand that the techniques disclosed in the following examples represent techniques that the inventors have found can be used to implement the present invention, and therefore can be regarded as preferred embodiments for implementing the present invention. However, those skilled in the art should understand from this specification that many modifications can be made to the specific embodiments disclosed here, and still obtain the same or similar results without departing from the spirit or scope of the present invention.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention belongs. The materials cited herein and their citations will be incorporated by reference. Those skilled in the art will realize or can learn through routine experiments many equivalent techniques of many specific embodiments of the invention described herein. These equivalents will be included in the claims.

[0026] The technical solutions of this patent will be further described in detail below in conjunction with specific embodiments.

[0027] As Figure 1 shown, the method for preparing zeolite based on waste incineration fly ash provided by the present invention includes the following steps:

[0028] (1) The waste incineration fly ash with a silicon-aluminum mass ratio of (1.1 - 1.5):1 is subjected to acid washing to remove impurities and then washed with deionized water by suction filtration; the acid is one of acetic acid, propionic acid, butyric acid, succinic acid, and lactic acid; the concentration of the acid is 0.2 - 1 mol / L; the mass ratio of the acid to the fly ash is (2 - 5):1, and the stirring time during acid washing is 3 - 5 h.

[0029] (2) A mixture of FeCl3 and FeSO4 is added to the waste incineration fly ash dried by water washing. The mass ratio of FeSO4 to FeCl3 in the mixture is (5 - 6):1, and the mass ratio of the fly ash obtained by water washing to the above mixture is (5 - 10):1; after mixing with an alkali solution with a concentration of 2 - 4 mol / L, it is put into a ball mill tank together with grinding balls. The liquid-solid mass ratio is (3 - 5):1, and the ratio of the mass of the grinding balls to the solid is (10 - 20):1; while ball milling, the reaction materials are heated. The rotation speed of the ball mill is 300 - 700 r / min, and the ball milling time is 2 - 10 hours; the ball mill tank is a high-temperature ball mill, and the temperature inside the ball mill tank is maintained at 100 - 300 °C; zeolite is prepared.

[0030] Among them, before the waste incineration fly ash in step (1) is subjected to acid washing to remove impurities, it can also be calcined and activated at a temperature of 650 - 750 °C.

[0031] Example 1

[0032] Taking waste incineration fly ash with a silicon-aluminum mass ratio of 1.1:1 as the raw material, adding 0.5 mol / L acetic acid, controlling the mass ratio of acetic acid to fly ash as 2:1, and stirring for 3 h. Deionized water is added to the obtained solid for suction filtration to wash away impurities. Take FeSO4 and FeCl3 mixed in a mass ratio of 5:1, mix the fly ash obtained by water washing with the above mixture in a mass ratio of 5:1, then add 2 mol / L sodium hydroxide solution for mixing, keep the liquid-solid mass ratio as 3:1, add grinding balls to make the ratio of the mass of the grinding balls to the fly ash as 15:1, and put it into a 200 mL zirconia ball mill tank. Place the ball mill tank in a planetary ball mill, set the rotation speed at 600 r / m, ball mill for 4 h, and use a high-temperature ball mill for heating to keep the temperature of the ball mill tank at 100 °C. After ball milling, a zeolite phase is obtained.

[0033] Example 2

[0034] Other processes are the same as those in Example 1, the difference is: replacing 0.5 mol / L acetic acid with 0.5 mol / L propionic acid.

[0035] Example 3

[0036] Other processes are the same as those in Example 1, the difference is: replacing 0.5 mol / L acetic acid with 0.5 mol / L nitric acid.

[0037] Example 4

[0038] Other processes are the same as those in Example 1, except that 0.5 mol / L acetic acid is replaced with 0.5 mol / L hydrochloric acid.

[0039] Example 5

[0040] Other processes are the same as those in Example 1, except that the pickling and impurity removal process is deleted, and the original ash is directly used for ball milling to synthesize zeolite.

[0041] Examples 1 to 5 above explored the influence of the pickling step in the preparation process. The zeolite materials prepared using Examples 1 to 5 above were used for the adsorption experiments of copper and ammonia nitrogen:

[0042] 0.4 g of the zeolite material prepared above was mixed with 200 ml of the simulated solution, stirred at 120 rpm for half an hour, and centrifuged at 5500 rpm for 5 minutes to obtain the supernatant and the separated slurry. The initial concentrations of copper and ammonia nitrogen in the simulated solution were both 200 mg / L.

[0043] The adsorption results of the zeolite materials prepared in Examples 1 to 5 are shown in Table 1.

[0044] Table 1 Adsorption results of zeolite materials

[0045]

[0046] The results show that the pickling process is beneficial to improving the adsorption performance of zeolite. In terms of the type of acid used in the pickling process, the effect of pickling with organic acid is better than that of pickling with inorganic acid.

[0047] Example 6

[0048] Other preparation processes are the same as those in Example 1, except that the concentration of the NaOH solution in the ball milling process is 1 mol / L.

[0049] Example 7

[0050] Other preparation processes are the same as those in Example 1, except that the concentration of the NaOH solution in the ball milling process is 3 mol / L.

[0051] Example 8

[0052] Other preparation processes are the same as those in Example 1, except that the concentration of the NaOH solution in the ball milling process is 4 mol / L.

[0053] Examples 6 to 8 above explored the influence of the concentration of the NaOH solution in the ball milling process during the preparation process. The zeolite materials prepared using Examples 6 to 8 above were used for the adsorption experiments of copper and ammonia nitrogen:

[0054] Mix 0.4 g of the zeolite material prepared above with 200 ml of the simulated solution, stir at 120 rpm for half an hour, and centrifuge at 5500 rpm for 5 minutes to obtain the supernatant and the separated slurry. The initial concentrations of copper and ammonia nitrogen in the simulated solution are both 200 mg / L.

[0055] The adsorption results of the zeolite materials prepared in Examples 6 to 8 are shown in Table 2.

[0056] Table 2 Adsorption results of zeolite materials

[0057]

[0058] The results show that during the ball milling process of preparing zeolite using municipal solid waste incineration fly ash, the concentration of the NaOH solution has a significant effect on the adsorption performance of the zeolite. The concentration of the NaOH solution cannot be too low. When the concentration is greater than 2 mol / L, the prepared zeolite has better adsorption performance.

[0059] Example 9

[0060] Other preparation processes are the same as those in Example 1, except that: during the ball milling process, the mass ratio of FeSO4 to FeCl3 is 5.5:1.

[0061] Example 10

[0062] Other preparation processes are the same as those in Example 1, except that: during the ball milling process, the mass ratio of FeSO4 to FeCl3 is 6:1.

[0063] Examples 9 to 10 above explored the influence of the mass ratio of FeSO4 to FeCl3 during the ball milling process in the preparation process. The adsorption experiments of copper and ammonia nitrogen were carried out using the zeolite materials prepared in Examples 9 to 10:

[0064] Mix 0.4 g of the zeolite material prepared above with 200 ml of the simulated solution, stir at 120 rpm for half an hour, and centrifuge at 5500 rpm for 5 minutes to obtain the supernatant and the separated slurry. The initial concentrations of copper and ammonia nitrogen in the simulated solution are both 200 mg / L.

[0065] The adsorption results of the zeolite materials prepared in Examples 9 to 10 are shown in Table 3.

[0066] Table 3 Adsorption results of zeolite materials

[0067]

[0068] The results show that during the ball milling process of preparing zeolite using municipal solid waste incineration fly ash, the mass ratio of FeSO4 to FeCl3 used for modification affects the adsorption performance of the zeolite. When the mass ratio of FeSO4 to FeCl3 is 5.5:1, the effect is better than 5:1 and 6:1.

[0069] Example 11

[0070] Using waste incineration fly ash with a silicon-aluminum mass ratio of 1.1:1 as the raw material, add 0.5 mol / L acetic acid, control the mass ratio of acetic acid to fly ash to be 2:1, and stir for 3 h. Add deionized water to the obtained solid and filter by suction to wash away impurities. Take the washed fly ash, add 2 mol / L sodium hydroxide solution to it and mix, keep the liquid-solid mass ratio at 3:1, add grinding balls so that the mass ratio of grinding balls to fly ash is 15:1, and place it in a 200 mL zirconia ball mill pot. Put the ball mill pot into a planetary ball mill, set the rotation speed at 600 r / m, ball mill for 4 h, and use a high-temperature ball mill to heat, keeping the temperature of the ball mill pot at 100 °C. After ball milling, a zeolite phase is obtained.

[0071] Example 12

[0072] Using waste incineration fly ash with a silicon-aluminum mass ratio of 1.3:1 as the raw material, add 1 mol / L succinic acid, control the mass ratio of propionic acid to fly ash to be 5:1, and stir for 5 h. Add deionized water to the obtained solid and filter by suction to wash away impurities. Take a mixture of FeSO4 and FeCl3 with a mass ratio of 5.5:1, mix the washed fly ash with the above mixture at a mass ratio of 9:1, then add 3 mol / L sodium hydroxide solution to mix, keep the liquid-solid mass ratio at 5:1, add grinding balls so that the mass ratio of grinding balls to fly ash is 20:1, and place it in a 500 mL zirconia ball mill pot. Put the ball mill pot into a planetary ball mill, set the rotation speed at 700 r / m, ball mill for 6 h, and use a high-temperature ball mill to heat, keeping the temperature of the ball mill pot at 200 °C. After ball milling, a zeolite phase is obtained.

[0073] Example 13

[0074] Using waste incineration fly ash with a silicon-aluminum mass ratio of 1.5:1 as the raw material, add 0.5 mol / L butyric acid, control the mass ratio of butyric acid to fly ash to be 3:1, and stir for 4 h. Add deionized water to the obtained solid and filter by suction to wash away impurities. Take a mixture of FeSO4 and FeCl3 with a mass ratio of 5.3:1, mix the washed fly ash with the above mixture at a mass ratio of 7:1, then add 4 mol / L sodium hydroxide solution to mix, keep the liquid-solid mass ratio at 4:1, add grinding balls so that the mass ratio of grinding balls to fly ash is 10:1, and place it in a 600 mL zirconia ball mill pot. Put the ball mill pot into a planetary ball mill, set the rotation speed at 500 r / m, ball mill for 8 h, and use a high-temperature ball mill to heat, keeping the temperature of the ball mill pot at 300 °C. After ball milling, a zeolite phase is obtained.

[0075] Example 14

[0076] Using waste incineration fly ash calcined at 650 °C as raw material, add 0.8 mol / L lactic acid, control the mass ratio of lactic acid to fly ash as 5:1, and stir for 3 h. Add deionized water to the obtained solid for suction filtration to wash away impurities. Take FeSO4 and FeCl3 mixed in a mass ratio of 6:1, mix the fly ash obtained by water washing with the above mixture in a mass ratio of 10:1, then add 4 mol / L sodium hydroxide solution for mixing, keep the liquid-solid mass ratio as 4:1, add grinding balls so that the mass ratio of grinding balls to fly ash is 20:1, and place it in a 1000 mL zirconia ball mill pot. Place the ball mill pot in a planetary ball mill, set the rotation speed at 600 r / m, ball mill for 10 h, use a high-temperature ball mill for heating to keep the temperature of the ball mill pot at 200 °C. After ball milling, a zeolite phase is obtained.

[0077] Example 15

[0078] Using waste incineration fly ash calcined at 750 °C as raw material, add 0.5 mol / L acetic acid, control the mass ratio of acetic acid to fly ash as 3:1, and stir for 5 h. Add deionized water to the obtained solid for suction filtration to wash away impurities. Take FeSO4 and FeCl3 mixed in a mass ratio of 5.5:1, mix the fly ash obtained by water washing with the above mixture in a mass ratio of 10:1, then add 3 mol / L sodium hydroxide solution for mixing, keep the liquid-solid mass ratio as 5:1, add grinding balls so that the mass ratio of grinding balls to fly ash is 15:1, and place it in a 700 mL zirconia ball mill pot. Place the ball mill pot in a planetary ball mill, set the rotation speed at 700 r / m, ball mill for 2 h, use a high-temperature ball mill for heating to keep the temperature of the ball mill pot at 300 °C. After ball milling, a zeolite phase is obtained.

[0079] Example 16

[0080] Using waste incineration fly ash calcined at 650 °C as raw material, add 0.8 mol / L propionic acid, control the mass ratio of propionic acid to fly ash as 5:1, and stir for 5 h. Add deionized water to the obtained solid for suction filtration to wash away impurities. Take FeSO4 and FeCl3 mixed in a mass ratio of 5.8:1, mix the fly ash obtained by water washing with the above mixture in a mass ratio of 5:1, then add 3 mol / L sodium hydroxide solution for mixing, keep the liquid-solid mass ratio as 4:1, add grinding balls so that the mass ratio of grinding balls to fly ash is 20:1, and place it in a 500 mL zirconia ball mill pot. Place the ball mill pot in a planetary ball mill, set the rotation speed at 400 r / m, ball mill for 5 h, use a high-temperature ball mill for heating to keep the temperature of the ball mill pot at 200 °C. After ball milling, a zeolite phase is obtained.

[0081] Comparative Example 1

[0082] Using waste incineration fly ash as raw material, prepare zeolite by ordinary hydrothermal synthesis method:

[0083] The fly ash from 4g of waste incineration was pickled with 1mol / L acetic acid, activated by ball milling for 0.5h after drying, and hydrothermally synthesized by adding 20ml of deionized water. The synthesis temperature was 180°C and the hydrothermal synthesis time was 12h to obtain a zeolite phase.

[0084] The zeolite adsorption performance of the zeolite materials prepared under different synthesis conditions and synthesis methods in Example 1, Examples 11 to 16, and Comparative Example 1 was investigated: adsorption experiments of copper, mercury, ammonia nitrogen, and cesium were carried out. 0.4g of the zeolite material prepared above was mixed with 200ml of the simulated solution, stirred at 120rpm for half an hour, and centrifuged at 5500rpm for 5 minutes to obtain the supernatant and the separated slurry. The initial concentrations of copper, mercury, ammonia nitrogen, and cesium in the simulated solution were all 200mg / L.

[0085] The adsorption results of the zeolite materials prepared in Examples 11 to 16 and Comparative Example 1 are shown in Table 4.

[0086] Table 4 Adsorption results of zeolite materials

[0087]

[0088] The results showed that without modification by adding FeSO4 and FeCl3, the adsorption performance of the zeolite was poor: the adsorption performance for copper was even weaker than that of the zeolite prepared by the conventional hydrothermal method, but the adsorption performance for mercury, ammonia nitrogen, and cesium was better than that of the zeolite prepared by the conventional hydrothermal method.

[0089] When the mass ratio of FeSO4 to FeCl3 used for modification was controlled at 5.5:1, the zeolite prepared showed better adsorption performance for copper, mercury, ammonia nitrogen, and cesium.

[0090] Example 17

[0091] The zeolite that had completed the adsorption experiment in Example 1 was recovered using a magnet. The zeolite material was immersed in 1mol / L NaCl aqueous solution (100ml) for about 30min to obtain the once-recovered zeolite.

[0092] Example 18

[0093] The zeolite that had completed the adsorption experiment in Example 17 was recovered using a magnet. The zeolite material was immersed in 1mol / L NaCl aqueous solution (100ml) for about 30min and then adsorbed, and then similarly recovered and desorbed in 1mol / L NaCl aqueous solution (100ml), and then adsorbed again to obtain the three-times-recovered zeolite.

[0094] Example 19

[0095] The zeolite in Example 1 was recovered 6 times using the method of Example 18 to obtain the six-times-recovered zeolite.

[0096] The zeolite materials under different recycling times in Examples 17 to 19 above were used to explore the zeolite adsorption performance: adsorption experiments of copper, mercury, ammonia nitrogen, and cesium were carried out. 0.4 g of the zeolite material prepared above was mixed with 200 ml of the simulated solution, stirred at 120 rpm for half an hour, and centrifuged at 5500 rpm for 5 minutes to obtain the supernatant and the separated slurry. The initial concentrations of copper, mercury, ammonia nitrogen, and cesium in the simulated solution were all 200 mg / L.

[0097] The comparison of the adsorption results of the zeolite materials prepared in Example 1, Examples 17 to 19, and Comparative Example 1 is shown in Table 5.

[0098] Table 5 Adsorption Results of Zeolite Materials

[0099]

[0100] The results show that: for the zeolite prepared by the present scheme, the adsorption of copper is basically not affected, and the adsorption capacity of copper does not change. The degradation rates of the adsorption performance of mercury, ammonia nitrogen, and cesium are as follows: after the first recycling and then re-adsorption and utilization, the degradation rates are: mercury 2.22%, ammonia nitrogen 0.47%, cesium 0.55%; after the third recycling and then re-adsorption and utilization, the degradation rates are respectively: mercury 2.22%, ammonia nitrogen 0.47%, cesium 0.55%; after the sixth recycling and then re-adsorption and utilization, the degradation rates are respectively: mercury 26.67%, ammonia nitrogen 15.06%, cesium 20.08%. After six recycling and then re-adsorption and utilization, its adsorption performance for copper, mercury, ammonia nitrogen, and cesium is still better than that of the zeolite prepared by the ordinary hydrothermal synthesis method, showing good reusability.

[0101] All the documents mentioned in the present invention are cited in this application as references, just as if each document is cited separately as a reference. In addition, it should be understood that after reading the above teachings of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by this application.

Claims

1. A method for preparing zeolite based on waste incineration fly ash, characterized in that: The steps include: The fly ash from garbage incineration is acid-washed to remove impurities and then washed with water; A mixture of FeCl3 and FeSO4 is added to the washed and dried waste incineration fly ash, and after mixing with alkali solution, it is put into a ball mill together with grinding balls for mechanochemical reaction, and the reaction materials are heated while ball milling to prepare zeolite; In step (2), the mass ratio of FeSO4 to FeCl3 in the mixture is 5.5:1, and the mass ratio of the fly ash obtained by water washing to the above mixture is (5-10):1; In the ball mill, the mass ratio of grinding balls to solids is (10-20):1, the rotation speed of the ball mill is 300-700 r / min, and the ball milling time is 2-10 hours; The concentration of the alkali solution is 2-4 mol / L, and the liquid-solid mass ratio of the alkali solution to the fly ash is (3-5):1; The acid used for pickling and impurity removal is one of acetic acid, propionic acid, butyric acid, succinic acid and lactic acid; the concentration of the acid is 0.2-1 mol / L.

2. The method for preparing zeolite based on waste incineration fly ash according to claim 1, characterized in that: During the pickling and impurity removal process, the mass ratio of acid to fly ash is (2-5):1, and the stirring time during the pickling process is 3-5h.

3. The method for preparing zeolite based on waste incineration fly ash according to claim 1, characterized in that: The mass ratio of silicon to aluminum in the waste incineration fly ash is (1.1-1.5):

1.

4. The method for preparing zeolite based on waste incineration fly ash according to claim 1, characterized in that: In step (1), the waste incineration fly ash is calcined and activated at a temperature of 650-750°C before being acid washed to remove impurities.

5. The method for preparing zeolite based on waste incineration fly ash according to claim 1, characterized in that: The ball mill is a high-temperature ball mill, and the temperature inside the ball mill is maintained at 100-300°C.

6. A zeolite, characterized in that: The method is prepared by any one of claims 1 to 5.

7. Use of the zeolite according to claim 6 for the efficient adsorption of heavy metals such as copper, mercury, cesium and ammonia nitrogen in liquid.

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