Bone meal filter material, preparation method thereof and self-compacting permeable concrete containing the same

Abstract

The present invention provides a bone meal filter material, a preparation method thereof, and self-compacting permeable concrete containing the same. The bone meal filter material comprises the following components in parts by weight: 70-80 parts modified bone meal, 3-5 parts attapulgite, 10-15 parts cement, 2-4 parts anhydrous sodium sulfate, 2-3 parts gypsum, 1-3 parts clay, 1-2 parts fly ash, 1-2 parts anorthite, and 5-15 parts water. The modified bone meal is prepared by grinding discarded livestock and poultry bones with an activator and then modifying them with a modifier. The bone meal filter material is prepared by molding and sintering a green raw material prepared by mixing the above components. The bone meal filter material has excellent adsorption effects on heavy metal ions, and the permeable concrete prepared therefrom has the advantages of reducing alkali, eliminating the need for vibration, adsorbing heavy metals, and being self-compacting.

Description

Technical Field

[0001] The invention relates to the technical field of environmental water treatment and building materials, and in particular to a bone meal filter material, a preparation method thereof and self-compacting permeable concrete containing the bone meal filter material. Background Art

[0002] How to deal with discarded kitchen waste and livestock and poultry bones has become a major problem because they are hard and difficult to degrade.

[0003] Improving the reuse rate of discarded livestock and poultry bones is urgent. Currently, the main treatment options for discarded livestock and poultry bones include direct landfilling, pulverization, and heavy metal absorption through bone char. Direct landfilling and pulverization not only pollute the environment but also waste resources. Bone char absorption has drawbacks such as a complex preparation process, environmental requirements, and limited usability, making it difficult to process and reuse large quantities of discarded livestock and poultry bones.

[0004] With the large-scale development of industry, a large amount of lead- and chromium-containing wastewater has been generated. The current method for cleaning lead- and chromium-containing wastewater is mainly to add modifiers to make it precipitate and then remove it. This method is not only expensive, but the PH of the precipitated water needs to be adjusted before it can be discharged. Summary of the Invention

[0005] In order to solve the problems existing in the background technology, the present invention provides a bone meal filter material, a preparation method thereof and a self-compacting permeable concrete containing the same. The bone meal filter material has an excellent adsorption effect on heavy metal ions, and the prepared permeable concrete has the advantages of alkali reduction, vibration-free, heavy metal adsorption and self-compacting.

[0006] The technical solution of the present invention to solve the above technical problems is as follows:

[0007] In a first aspect, the present invention provides a bone meal filter material comprising the following components in parts by weight:

[0008] 70-80 parts of modified bone meal;

[0009] 3-5 parts of attapulgite;

[0010] 10-15 parts of cement;

[0011] 2-4 parts of anhydrous sodium sulfate;

[0012] 2-3 parts of gypsum;

[0013] 1-3 parts clay;

[0014] 1-2 parts fly ash;

[0015] 1-2 parts of calcium feldspar;

[0016] 5-15 parts water;

[0017] The modified bone powder is prepared by grinding discarded kitchen waste livestock and poultry bones with an activator and then modifying with a modifier;

[0018] The bone powder filter material is prepared by molding and sintering a green raw material prepared by mixing the above components.

[0019] According to the above scheme, the activator includes quicklime, zinc chloride and magnesium chloride, and the mass ratio of the quicklime, zinc chloride and magnesium chloride is (2-4):(1-3):(1-3); the modifier includes polyacrylamide, microcrystalline cellulose and aluminum chloride, and the mass ratio of the polyacrylamide, microcrystalline cellulose and aluminum chloride is (1-3):(2-4):(1-3); the mass ratio of the discarded kitchen waste livestock and poultry bones to the activator and modifier is 100:(4-6):(0.2-0.3).

[0020] Preferably, the bone powder filter material is obtained by molding green raw materials, sintering and then encapsulating them.

[0021] According to the above scheme, the filter material green body is sintered and then immersed in the shell slurry for shelling. The shell slurry is mixed with cement, silica fume and water in a mass ratio of (2-3): (1-2): (5-7).

[0022] Preferably, active powder is added during the molding process, and the active powder is a mixture of kaolin, fly ash and coal gangue in a mass ratio of (1-3): (5-8): (2-4), and the mass ratio of the active powder to the green body raw material is (2-5):100.

[0023] Furthermore, the bone powder filter material can be in various shapes, preferably spherical, and more preferably, has a particle size of 10 to 25 mm.

[0024] Spherical filter media can be added to concrete to achieve the effect of no vibration.

[0025] The beneficial effects of the present invention are:

[0026] 1) The main component of the bone powder filter material is discarded kitchen waste livestock and poultry bones, which is a waste utilization, not only low cost, but also reduces the pollution of discarded kitchen waste livestock and poultry bones to the environment, and provides a method for large-scale reuse of discarded kitchen waste livestock and poultry bones;

[0027] 2) The present invention grinds and activates discarded livestock and poultry bones, and then sintering them with other components to form a bone carbon structure with hydroxyapatite. This structure has a mesoporous structure, negatively charged surface sites, and anionic groups, which can deposit heavy metals to form a crystalline phase, achieving the effect of heavy metal adsorption.

[0028] 3) The modification of quicklime and aluminum chloride improves the adsorption of fluoride ions by the filter material;

[0029] 4) Adding active powder during the filter media molding process and coating the filter media after sintering not only increases the strength of the filter media but also enhances its adsorption of heavy metals. The cement and silica fume in the coating slurry undergo a hydration reaction, providing alkali and calcium, enhancing heavy metal precipitation and ion exchange performance, and improving the filter media's adsorption of heavy metals such as lead and chromium.

[0030] In a second aspect, the present invention provides a method for preparing the above-mentioned bone powder filter material, comprising the following steps:

[0031] S1. The discarded kitchen waste livestock and poultry bones are ground with an activator and then modified with a modifier to prepare a modified bone meal;

[0032] S2. Weigh the components of the green material according to their mass fractions, stir and mix them, and then form and sinter to obtain the bone powder filter material.

[0033] According to the above scheme, the activator includes quicklime, zinc chloride and magnesium chloride in a mass ratio of (2-4):(1-3):(1-3), the modifier includes polyacrylamide, microcrystalline cellulose and aluminum chloride in a mass ratio of (1-3):(2-4):(1-3), and the mass ratio of the discarded kitchen waste livestock and poultry bones to the activator and modifier is 100:(4-6):(0.2-0.3).

[0034] According to the above scheme, active powder is added during the molding process in step S2, and the active powder is mixed with kaolin, fly ash and coal gangue in a mass ratio of (1-3): (5-8): (2-4), and the filter material green body is obtained after molding; the sintering conditions are: preheating at 150-200°C for 15-20 minutes and then heating to 450-550°C and roasting for 0.5-1h; after sintering, it also includes shelling, and the specific steps of shelling are: immersing the filter material green body in shelling slurry after sintering, and then drying it. The shelling slurry is mixed with cement, silica fume and water in a mass ratio of (2-3): (1-2): (5-7).

[0035] According to the above scheme, the filter material green body formed by molding can be of various shapes and specifications. If spherical filter material is prepared, a granulator and a ball forming machine can be used to prepare spherical filter material with different particle sizes.

[0036] In a third aspect, the present invention also provides a self-compacting permeable concrete comprising the above-mentioned bone meal filter material.

[0037] According to the above scheme, the self-compacting permeable concrete includes the following components in parts by weight: 8 to 12 parts of cement, 2 to 4 parts of fly ash, 1 to 2 parts of silica fume, 65 to 85 parts of bone meal filter material, 3 to 5 parts of anhydrous calcium chloride, 1 to 3 parts of bentonite, 5 to 10 parts of water, 1 to 2 parts of water reducer, 3 to 5 parts of superphosphate, and 4 to 6 parts of potassium dihydrogen phosphate.

[0038] On the one hand, the permeable concrete can absorb fluoride ions and heavy metals such as lead and chromium in water. On the other hand, cement and silica fume are used as binders, and fly ash and anhydrous calcium chloride are used as alkali reducers to reduce the alkalinity of the voids in the permeable concrete. The spherical filter material can make the permeable concrete vibration-free and self-compacting. DETAILED DESCRIPTION

[0039] The principles and features of the present invention are described below with reference to the accompanying drawings and specific embodiments. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0040] The inventors prepared bone meal filter material by grinding and activating discarded livestock and poultry bones with an activator, modifying them with a modifier, and then mixing them with other auxiliary materials through molding, sintering, and encapsulation. This bone meal filter material has excellent fluoride ion and heavy metal adsorption properties and can be used to prepare permeable concrete.

[0041] The bone meal filter material of the present invention comprises the following components in parts by weight:

[0042] 70-80 parts of modified bone meal;

[0043] 3-5 parts of attapulgite;

[0044] 10-15 parts of cement;

[0045] 2-4 parts of anhydrous sodium sulfate;

[0046] 2-3 parts of gypsum;

[0047] 1-3 parts clay;

[0048] 1-2 parts fly ash;

[0049] 1-2 parts of calcium feldspar;

[0050] 5-15 parts water;

[0051] The modified bone powder is prepared by grinding discarded kitchen waste livestock and poultry bones with an activator and then modifying with a modifier;

[0052] The bone powder filter material is prepared by molding and sintering a green raw material prepared by mixing the above components.

[0053] Preferably, the activator includes quicklime, zinc chloride and magnesium chloride, and the mass ratio of the quicklime, zinc chloride and magnesium chloride is (2-4):(1-3):(1-3); the modifier includes polyacrylamide, microcrystalline cellulose and aluminum chloride, and the mass ratio of the polyacrylamide, microcrystalline cellulose and aluminum chloride is (1-3):(2-4):(1-3); the mass ratio of the discarded kitchen waste livestock and poultry bones to the activator and modifier is 100:(4-6):(0.2-0.3).

[0054] Preferably, the modifier is prepared into a modifier solution with a concentration of 0.5% to 1% and sprayed on the ground bone powder to modify the bone powder.

[0055] Preferably, the bone powder filter material is obtained by molding green raw materials, sintering and then encapsulating them.

[0056] Preferably, after the filter material green body is sintered, it is immersed in a cladding slurry for cladding, and the cladding slurry is mixed with cement, silica fume and water in a mass ratio of (2-3): (1-2): (5-7).

[0057] Preferably, active powder is added during the molding process, and the active powder is a mixture of kaolin, fly ash and coal gangue in a mass ratio of (1-3): (5-8): (2-4), and the mass ratio of the active powder to the green body raw material is (2-5):100.

[0058] The bone powder filter material can be in various shapes, preferably spherical, and more preferably, has a particle size of 10 to 25 mm.

[0059] The specific preparation method of the above-mentioned bone meal filter material is as follows:

[0060] 1. Preparation of modified bone meal

[0061] The waste kitchen waste livestock and poultry bones and an activator are placed in a ball mill and ball-milled at 30-40 r / min for 2-3 hours to obtain the waste kitchen waste livestock and poultry bone powder, which is then passed through a 100-mesh sieve. The mass ratio of the waste kitchen waste livestock and poultry bones to the activator is 100:4-6, and the activator components are quicklime:zinc chloride:magnesium chloride in the ratio of (2-4):(1-3):(1-3). The waste kitchen waste livestock and poultry bones include but are not limited to one or more of pig bones, cattle bones, sheep bones, etc.

[0062] Preferably, in order to ensure the quality of the waste kitchen waste livestock and poultry bone meal, the residue after passing through a 100-mesh sieve is less than 15%.

[0063] The modified bone powder is obtained by spraying a modifier solution on waste kitchen waste livestock and poultry bone powder, stirring the solution thoroughly, and leaving it for one day. The components of the modifier are polyacrylamide: microcrystalline cellulose: aluminum chloride (1-3): (2-4): (1-3). The modifier is added to water to prepare a modifier solution with a concentration of 0.5% to 1%. The mass ratio of the modifier to the waste kitchen waste livestock and poultry bones is 0.2-0.3:100.

[0064] 2. Preparation of filter material green materials

[0065] Weigh 70-80 parts of modified bone meal, 3-5 parts of attapulgite, 10-15 parts of cement, 2-4 parts of anhydrous sodium sulfate, 2-3 parts of gypsum, 1-3 parts of clay, 1-2 parts of fly ash, and 1-2 parts of calcium feldspar, mix well and set aside.

[0066] The cement used in the examples is ordinary Portland cement with a designation of P·O42.5, and the fly ash is Class II ash.

[0067] 3. Filter material forming

[0068] The filter material green body raw materials are poured into the granulator, and the filter material green body precursor is obtained through the cutting device, and then prepared into the required shape and specifications to obtain the filter material green body.

[0069] If the filter material is prepared into a spherical shape, the filter material green body precursor is dropped into a ball forming machine and then rotated in the ball forming machine until the filter material is spherical and not sticky, and then used for standby use. The particle size of the spherical filter material green body is preferably 10 to 25 mm.

[0070] More preferably, active powder is added to the filter material green body precursor during the molding process to prepare the filter material green body, wherein the active powder is kaolin: fly ash: coal gangue mixed and ground in the ratio of (1-3): (5-8): (2-4).

[0071] 4. Sintering of filter media

[0072] After drying the green filter material, place it in a muffle furnace, preheat it at 150-200°C for 15-20 minutes, then heat it to 450-550°C and bake it for 0.5-1 hour. Cool it to room temperature and set it aside.

[0073] In some preferred embodiments, after the filter material green body is sintered, 5. the filter material is coated.

[0074] The sintered filter material is soaked in the shell slurry for 2 to 6 hours, fished out and naturally cured to obtain the bone meal filter material, wherein the shell slurry comprises 20 to 30 parts of cement, 10 to 20 parts of silica fume and 50 to 70 parts of water.

[0075] The present invention also provides a self-compacting permeable concrete containing the bone meal filter material, which includes the following raw materials in parts by weight: 8 to 12 parts of cement, 2 to 4 parts of fly ash, 1 to 2 parts of silica fume, 65 to 85 parts of bone meal filter material, 3 to 5 parts of anhydrous calcium chloride, 1 to 3 parts of bentonite, 5 to 10 parts of water, 1 to 2 parts of a water reducer, 3 to 5 parts of superphosphate, and 4 to 6 parts of potassium dihydrogen phosphate.

[0076] The method for preparing the self-compacting permeable concrete comprises the following steps:

[0077] P1. Weigh each component in parts by weight;

[0078] P2. Stir the filter material and 3 / 4 of the water for 50-70s;

[0079] P3. Add cement, silica fume, and fly ash and continue mixing for 50-70 seconds.

[0080] P4. Add anhydrous calcium chloride, bentonite, superphosphate, potassium dihydrogen phosphate, the remaining 1 / 4 water and water reducer and continue stirring for 80-140 seconds to obtain self-compacting permeable concrete that does not require vibration.

[0081] Among them, 3 / 4 of the water and 1 / 4 of the water are 3 / 4 and 1 / 4 of the total water consumption.

[0082] In the embodiment of the present invention, the cement used is ordinary Portland cement with a P·O4 of 2.5, the fly ash is Class II ash, the mass fraction of zinc chloride is 80%-90%, and the mass fraction of magnesium chloride is 80%-90%.

[0083] Example 1

[0084] This embodiment provides a bone powder filter material and a preparation method thereof, the preparation method comprising the following steps:

[0085] 1) placing 50 parts by weight of pig bones, 35 parts of cattle bones, and 11 parts of other kitchen waste livestock and poultry bones in a ball mill, and crushing them for 2 hours to obtain kitchen waste livestock and poultry bone powder, wherein the ground and activated kitchen waste livestock and poultry bone powder passes through a 100-mesh sieve with a residue of less than 15%, and wherein the activator composition is quicklime: zinc chloride: magnesium chloride in a ratio of 2:2:1;

[0086] Weigh 0.3 parts of a modifier (the mass ratio of polyacrylamide: microcrystalline cellulose: aluminum chloride is 3:2:2), dissolve it in 30 parts of water, and prepare a 1% modifier solution. Spray the modified solution on discarded kitchen waste and livestock bone meal, stir it thoroughly, and then leave it for a day and a night to obtain modified bone meal.

[0087] 2) Weigh 70 parts of modified bone meal, 4 parts of attapulgite, 12 parts of cement, 3 parts of anhydrous sodium sulfate, 2 parts of gypsum, 2 parts of clay, 1 part of fly ash, 1 part of anorthite, and 5 parts of water, stir well and set aside;

[0088] 3) The filter material green body raw material prepared in step 2) is introduced into a granulator, and the filter material green body precursor is obtained by a cutting device. The filter material green body precursor is dropped into a spheroidizer, and the active powder is added thereto. The active powder is rotated together until the filter material green body is spherical, with a particle size of 10 to 25 mm and is non-sticky to each other. The active powder is prepared by grinding a mixture of kaolin, fly ash, and coal gangue in a ratio of 2:6:2, and the mass ratio of the active powder to the green body raw material is 5:100.

[0089] 4) After drying the green filter material, place it in a muffle furnace, preheat it at 200°C for 15 minutes, then heat it to 450°C and bake it for 1 hour, then cool it to room temperature for later use;

[0090] 5) Soaking the filter material green body sintered in step 4) in a shelling slurry for 4 hours, removing it and subjecting it to natural curing to obtain the bone meal filter material, wherein the shelling slurry comprises 30 parts of cement, 20 parts of silica fume, and 50 parts of water.

[0091] Example 2

[0092] This embodiment provides a bone powder filter material and a preparation method thereof, the preparation method comprising the following steps:

[0093] 1) placing 40 parts by weight of pig bones, 45 parts of cattle bones, 9 parts of other waste kitchen and livestock bones, and 6 parts of an activator into a ball mill and crushing them for 3 hours to obtain waste kitchen and livestock bone meal, wherein the ground and activated waste kitchen and livestock bone meal passes through a 100-mesh sieve with a residue of less than 15%, and the activator composition comprises quicklime: zinc chloride: magnesium chloride in a ratio of 3:2:2;

[0094] Weigh 0.2 parts of the modifier (the mass ratio of polyacrylamide: microcrystalline cellulose: aluminum chloride is 2:4:1), dissolve it in 20 parts of water to prepare a modifier solution with a concentration of 1%, spray the waste kitchen waste livestock and poultry bone meal with the modified solution, stir it thoroughly, and then leave it for a day and night to obtain the modified bone meal.

[0095] 2) Weigh 75 parts of modified bone meal, 3 parts of attapulgite, 10 parts of cement, 2 parts of anhydrous sodium sulfate, 2 parts of gypsum, 1 part of clay, 1 part of fly ash, 1 part of anorthite, and 5 parts of water, stir well and set aside;

[0096] 3) The filter material green body raw material prepared in step 2) is introduced into a granulator, and the filter material green body precursor is obtained by a cutting device. The filter material green body precursor is dropped into a spheroidizer, and the active powder is added thereto. The active powder is rotated together until the filter material green body is spherical, with a particle size of 10 to 25 mm and is non-sticky to each other. The active powder is prepared by grinding a mixture of kaolin, fly ash, and coal gangue in a ratio of 3:5:3, and the mass ratio of the active powder to the green body raw material is 3:100.

[0097] 4) After drying the green filter material, place it in a muffle furnace, preheat it at 150°C for 20 minutes, then heat it to 550°C and calcine it for 0.5 hours, cool it to room temperature and set aside;

[0098] 5) Soaking the filter material green body sintered in step 4) in a shelling slurry for 4 hours, removing it and subjecting it to natural curing to obtain the bone meal filter material, wherein the shelling slurry comprises 25 parts of cement, 15 parts of silica fume, and 60 parts of water.

[0099] Example 3

[0100] This embodiment differs from Example 1 in that no active powder is added during the molding process. Specifically, step 3) involves introducing the filter material green body raw material prepared in step 2) into a granulator, cutting it through a cutting device to obtain a filter material green body precursor, which is then dropped into a pelletizer and rotated until the filter material green body is spherical with a particle size of 10 to 25 mm and is non-sticky. All other steps are the same as in Example 1.

[0101] Example 4

[0102] The difference between Example 4 and Example 1 is that no shelling is performed during the preparation of the filter material, that is, the filter material green body is directly sintered to obtain the bone powder filter material of this comparative example.

[0103] Comparative Example 1

[0104] In this comparative example, the discarded kitchen waste animal and poultry bone meal was not activated or modified, but was directly ground and crushed to prepare the filter material. Step 1) was to grind 50 parts of discarded kitchen waste pig bones, 35 parts of cattle bones, and 11 parts of other discarded kitchen waste animal and poultry bones by weight to obtain bone meal. The remaining steps were the same as in Example 1.

[0105] According to the provisions of GB / T17431.2-2010 "Light aggregate and its test method Part 2", the 24h water absorption rate and cylinder pressure strength of the filter materials of the examples and comparative examples were tested; according to the provisions of GB14685-201 "Pebbles and crushed stones for construction", the firmness of the filter materials of the examples and comparative examples was tested; according to the provisions of JC / T239-2014 "Autoclaved fly ash bricks", the frost resistance of the filter materials of the examples and comparative examples was tested. The test results are shown in Table 1.

[0106] Table 1 Performance of bone meal filter media

[0107]

[0108] As can be seen from Table 1, the filter material prepared using waste kitchen waste and livestock bone powder has a barrel compressive strength of 8.1-9.7 MPa, a firmness mass loss of 3.1%-4.1%, and a frost resistance mass loss of 1.7%-3.1%.

[0109] By comparing Example 1 and Comparative Example 1, it can be found that in Comparative Example 1, the filter material prepared using waste kitchen waste and livestock bone powder that has not been activated and modified has no significant difference in cylinder pressure strength, firmness and frost resistance of the filter material, indicating that the activation modifier of the present invention has no significant effect on the engineering mechanical properties of the filter material.

[0110] By comparing Example 1 and Example 3, it can be found that in Example 3, no active powder was used in the preparation of the filter material, and the cylinder pressure strength, firmness and frost resistance of the filter material all showed a significant decrease, indicating that the use of active powder composed of kaolin, fly ash and coal gangue can improve the engineering mechanical properties of the filter material prepared with waste kitchen waste and livestock and poultry bone meal.

[0111] By comparing Example 1 and Example 4, it can be found that the filter material prepared in Example 4 has not been coated, and the cylinder pressure strength, firmness and frost resistance of the filter material have all shown a significant decrease, indicating that coating with cement and silica ash slurry can improve the engineering mechanical properties of the filter material prepared with waste kitchen waste and livestock and poultry bone meal.

[0112] The adsorption effects of the filter materials of the embodiment and the comparative example were tested with an average total chromium concentration of 60 mg / L and an average total lead concentration of 500 mg / L in the influent. The test results are shown in Table 2.

[0113] Table 2 Heavy metal adsorption results of bone meal filter material

[0114]

[0115] As can be seen from Table 2, the bone meal filter materials prepared using modified bone meal in Examples 1 and 2 of the present invention have good adsorption effects on heavy metal chromium and lead. From the removal rate data of heavy metal chromium and lead, the removal rates of chromium in Examples 1 and 2 reach more than 99.4%, and the removal rates of lead reach more than 99.84%, indicating that the bone meal filter materials prepared using modified bone meal of the present invention have excellent heavy metal adsorption effects.

[0116] By comparing Example 1 and Comparative Example 1, it can be found that in Comparative Example 1, the filter material prepared using waste kitchen waste and livestock bone meal that has not been activated and modified has a significantly reduced removal rate of heavy metal chromium and lead, indicating that the activation modifier of the present invention has a significant modification effect on the adsorption of heavy metals on waste kitchen waste and livestock bone meal.

[0117] By comparing Example 1 and Example 4, it can be found that the filter material prepared in Example 4 has not been shelled. Judging from the removal rate data of heavy metal chromium and lead by the two, the adsorption effect of the unshelled filter material on chromium and lead is reduced, indicating that shelling with cement and silica ash slurry can improve the adsorption of heavy metals by the filter material prepared with waste kitchen waste and livestock and poultry bone meal.

[0118] By comparing Example 1 and Example 3, it can be found that no active powder was used in the preparation of the filter material in Example 3. Judging from the removal rate data of heavy metal chromium and lead by the two, the adsorption effect of the filter material without active powder on chromium and lead decreased, indicating that the active powder composed of kaolin, fly ash and coal gangue can improve the adsorption of heavy metals by the filter material prepared from waste kitchen waste and livestock and poultry bone meal.

[0119] Example 5

[0120] This embodiment provides a self-compacting permeable concrete, comprising the following raw materials by weight: 8 parts of cement, 3 parts of fly ash, 1 part of silica fume, 68 parts of the filter material of Example 1, 3 parts of anhydrous calcium chloride, 1 part of bentonite, 8 parts of water, 1 part of a water reducer, 3 parts of superphosphate, and 4 parts of potassium dihydrogen phosphate;

[0121] The method for preparing permeable concrete of this embodiment comprises the following steps:

[0122] P1. The filter material in Example 1 was pre-wetted for 24h;

[0123] P2. Weigh each component by weight;

[0124] P3. Rub the pre-wetted filter media until it is saturated and dry, then add 3 / 4 of water and stir for 50-70 seconds;

[0125] P4. Add cement, silica fume, and fly ash and continue mixing for 50-70 seconds;

[0126] P5. Add anhydrous calcium chloride, bentonite, superphosphate, potassium dihydrogen phosphate, the remaining 1 / 4 water and water reducer and continue stirring for 80-140 seconds to obtain self-compacting permeable concrete.

[0127] Comparative Example 2

[0128] The difference between Comparative Example 2 and Example 5 is that stones of the same particle size are used instead of the filter material in Example 5.

[0129] A 5 ppm chromium and lead solution with a pH of 3 was prepared, and the static heavy metal adsorption performance of the self-compacting permeable concrete prepared in Example 5 and Comparative Example 2 and the dynamic heavy metal adsorption performance under heavy rain (simulated heavy rain conditions: rainfall in the first to sixth hours were 3, 7, 10, 8, 6, and 2 mm, respectively, with an average rainfall of 6 mm / h and a duration of 6 h) were tested. The test results are shown in Table 3.

[0130] Table 3: Heavy metal adsorption results of self-compacting permeable concrete

[0131] Example Example 5 Comparative Example 2 Static heavy metal chromium removal rate 79.45％ 59.37％ Static heavy metal lead removal rate 80.67％ 60.29％ Dynamic heavy metal chromium removal rate 45.29％ 31.58％ Dynamic heavy metal lead removal rate 46.37％ 33.49％

[0132] As can be seen from Table 3, the static heavy metal removal rate of the self-compacting permeable concrete prepared using the filter material in Example 5 reached more than 79%, and the dynamic heavy metal removal rate reached more than 45%.

[0133] By comparing Example 5 and Comparative Example 2, it can be found that the self-compacting permeable concrete prepared with the bone meal filter material of the present invention has an excellent removal effect on heavy metals under both static and dynamic states. Compared with the permeable concrete prepared with stones of the same particle size, the heavy metal removal rate is higher and the adsorption effect on heavy metals is better.

[0134] The self-compacting permeable concrete of Example 5 and Comparative Example 2 was tested for performance indicators of water permeability grade, compressive strength, frost resistance and vibration expansion. The test results are shown in Table 4.

[0135] Table 4: Test results of self-compacting permeable concrete

[0136] Example Permeability grade Compressive strength / MPa Frost resistance / % Vibration expansion / mm Example 5 K6 25.5 2 250 Comparative Example 2 K4 20.2 3 180

[0137] As can be seen from Table 4, the self-compacting permeable concrete prepared using the filter material in Example 5 has a permeability coefficient grade of K6, a 28-day compressive strength of 25.5 MPa, a mass loss of 2% after 25 freeze-thaw cycles, and a vibration expansion of 250 mm.

[0138] By comparing Example 5 and Comparative Example 2, it can be found that the permeability coefficient grade of the self-compacting permeable concrete prepared with the filter material of the present invention can reach K6 level, which is higher than the permeability coefficient grade of the permeable concrete prepared with stones of the same particle size; the 28-day compressive strength and frost resistance of the permeable concrete prepared with the filter material of the present invention are superior to those of the permeable concrete prepared with stones of the same particle size; the vibration expansion of the self-compacting permeable concrete prepared with the filter material of the present invention is superior to that of the permeable concrete prepared with stones of the same particle size, indicating that the filter material of the present invention can be used to prepare self-compacting permeable concrete with better permeability effect, compressive strength, frost resistance and expansion than stones of the same particle size.

[0139] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A bone meal filter material, characterized in that: The composition comprises the following components in parts by weight: 70-80 parts of modified bone meal; 3-5 parts of attapulgite; 10-15 parts of cement; 2-4 parts of anhydrous sodium sulfate; 2-3 parts of gypsum; 1-3 parts clay; 1-2 parts fly ash; 1-2 parts of calcium feldspar; 5-15 parts water; The modified bone meal is prepared by grinding waste kitchen waste livestock and poultry bones with an activator and then modifying with a modifier, wherein the activator comprises quicklime, zinc chloride and magnesium chloride in a mass ratio of (2-4):(1-3):(1-3), and the modifier comprises polyacrylamide, microcrystalline cellulose and aluminum chloride in a mass ratio of (1-3):(2-4):(1-3), and the mass ratio of the waste kitchen waste livestock and poultry bones to the activator and the modifier is 100:(4-6):(0.2-0.3); The bone powder filter material is prepared by molding and sintering a green raw material prepared by mixing the above components.

2. The bone powder filter material according to claim 1, characterized in that The bone powder filter material is prepared by forming a green raw material, sintering it and then encapsulating it.

3. The bone powder filter material according to claim 2, characterized in that: Active powder is added during the molding process. The active powder is mixed with kaolin, fly ash and coal gangue in a mass ratio of (1-3): (5-8): (2-4). The mass ratio of the active powder to the green body raw material is (2-5):

100.

4. The bone meal filter material according to claim 3, characterized in that The bone powder filter material is spherical and has a particle size of 10 to 25 mm.

5. The method for preparing the bone powder filter material according to any one of claims 1 to 4, characterized in that: The steps include: S1. The discarded kitchen waste livestock and poultry bones are ground with an activator and then modified with a modifier to prepare a modified bone meal; S2. Weigh the components of the green material according to their mass fractions, stir and mix them, and then form and sinter to obtain the bone powder filter material.

6. The method for preparing bone powder filter material according to claim 5, characterized in that: The activator includes quicklime, zinc chloride and magnesium chloride in a mass ratio of (2-4):(1-3):(1-3); the modifier includes polyacrylamide, microcrystalline cellulose and aluminum chloride in a mass ratio of (1-3):(2-4):(1-3); the mass ratio of the discarded kitchen waste livestock and poultry bones to the activator and modifier is 100:(4-6):(0.2-0.3).

7. The method for preparing bone powder filter material according to claim 5, characterized in that: In step S2, active powder is added during the molding process, wherein the active powder is a mixture of kaolin, fly ash and coal gangue in a mass ratio of (1-3): (5-8): (2-4), and the filter material green body is obtained by molding; the sintering conditions are: preheating at 150-200° C. for 15-20 minutes, then heating to 450-550° C. and calcining for 0.5-1 hour; After sintering, the process also includes cladding. The specific steps of cladding are: immersing the filter material green body into cladding slurry after sintering, and then drying. The cladding slurry is made by mixing cement, silica fume and water in a mass ratio of (2-3): (1-2): (5-7).

8. A self-compacting permeable concrete, characterized in that: The invention comprises the bone powder filter material according to any one of claims 1 to 4.

9. The self-compacting permeable concrete according to claim 8, characterized in that: The self-compacting permeable concrete comprises the following components in parts by weight: 8-12 parts of cement, 2-4 parts of fly ash, 1-2 parts of silica fume, 65-85 parts of bone meal filter material, 3-5 parts of anhydrous calcium chloride, 1-3 parts of bentonite, 5-10 parts of water, 1-2 parts of water reducer, 3-5 parts of superphosphate, and 4-6 parts of potassium dihydrogen phosphate.

Images