Composite silicate filter material with efficient phosphorus removal function and preparation method

Abstract

The invention discloses a composite silicate filter material with an efficient phosphorus removal function and a preparation method, and relates to the technical field of filter materials, the composite silicate filter material with the efficient phosphorus removal function and the preparation method are prepared from the following raw materials: superfine slag powder, Portland cement, gypsum powder, fly ash and lime powder; wherein the superfine slag powder and the Portland cement are included. According to the composite silicate filter material with the efficient phosphorus removal function, the cement powder, the coal power plant waste fly ash, the waste slag powder generated in the blast furnace ironmaking process and the like are used as raw materials, and compared with common filter materials such as clay ceramsite, the used raw materials are low in cost and easy to obtain, the process is simple, and the requirements for a production line and equipment are low; meanwhile, the filter material also has the effect of recycling wastes, the soluble nitrogen and phosphorus components in the material are extremely low, the release amounts of ammonia nitrogen and total phosphorus are less than 0.0005 mg / g and 0.005 mg / g when the filter material is soaked in water for more than 48 hours, the release amount of COD (Chemical Oxygen Demand) is 0, and the filter material has no nitrogen and phosphorus pollution risk when being practically applied to water treatment.

Description

Technical Field

[0001] The invention relates to the technical field of filtering materials, and in particular to a composite silicate filtering material with high-efficiency phosphorus removal function and a preparation method thereof. Background Art

[0002] Phosphorus is the main pollutant in my country's lakes, reservoirs and rivers. Excessive phosphorus can lead to eutrophication and algal bloom, thus destroying the aquatic ecosystem. Sewage discharge is the main source of phosphorus in water bodies. Even if the effluent from urban sewage treatment plants meets the Class A standard, that is, less than 0.5 mg / L, its discharge will still cause a large amount of phosphorus to enter natural water bodies and aggravate a series of water ecological problems caused by excessive phosphorus. Therefore, it is urgent to carry out deep phosphorus removal treatment on the tail water of urban sewage treatment plants to prevent or improve the problem of phosphorus pollution in natural water bodies;

[0003] Common phosphorus removal technologies for sewage tail water usually include chemical precipitation, physical filtration, adsorption, etc., but chemical phosphorus removal is costly, can produce a large amount of metal-containing sludge, and is more suitable for high-phosphorus wastewater rather than sewage plant tail water with lower phosphorus concentration; conventional filtration methods, such as sand filtration, have low phosphorus removal efficiency and limited treatment capacity, and are not suitable for treating large amounts of sewage. The adsorption method utilizes adsorbents to couple physical, chemical and biological multiple effects to remove phosphorus. It has the advantages of good effect and wide application range in deep phosphorus removal from tail water, but commonly used adsorbents such as gravel and expanded clay have high production costs and poor adsorption capacity. In summary, there is an urgent need to develop a new filter material that has both high-efficiency phosphorus removal and low preparation cost to meet the growing demand for deep phosphorus removal from sewage tail water. Summary of the invention

[0004] The purpose of the present invention is to solve at least one of the technical problems existing in the prior art, and to provide a composite silicate filter material with efficient phosphorus removal function and a preparation method thereof, which can solve the problems of conventional filtration methods, such as sand filtration, low phosphorus removal efficiency, limited processing capacity, and unsuitability for treating large amounts of sewage. The adsorption method utilizes adsorbents to couple physical, chemical and biological multiple effects to remove phosphorus, and has the advantages of good effect and wide application range in deep phosphorus removal of tail water. However, commonly used adsorbents such as gravel and expanded clay have the problems of high production cost and poor adsorption capacity.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A composite silicate filter material with high-efficiency phosphorus removal function, comprising the following raw materials: slag powder, silicate cement, gypsum powder, fly ash, lime powder;

[0007] Among them, the ratio of slag powder, silicate cement, gypsum powder, fly ash and lime powder is (32-38): (22-25): (3-8): (22-28): (5-10).

[0008] A method for preparing a composite silicate filter material with high-efficiency phosphorus removal function comprises the following steps:

[0009] Step 1, raw material preparation: select slag powder, silicate cement, gypsum powder, fly ash, lime powder and mix them evenly, and the resulting mixture is recorded as A;

[0010] Step 2, mixing the mixture A obtained in the first step with water to form a premix B;

[0011] Step 3, the premix B and the pore-forming agent are measured and mixed evenly according to the mass percentage of B: pore-forming agent = 1: (0.05% to 0.20%), injected into a steel mold, and allowed to stand for foaming;

[0012] Step 4, after standing and foaming, cutting by a cutting machine to obtain raw material C;

[0013] Step 5, steaming the raw material C at 700-800° C. for 6-10 hours, and then naturally cooling it to room temperature to obtain a prefabricated material D;

[0014] Step six, after the prefabricated material D is crushed by a crusher, a screening machine is used to sort out the part with a particle size of 2 cm to 6 cm, thereby obtaining the composite silicate filter material prepared by the present invention with large-capacity and high-efficiency phosphorus removal and synergistic denitrification and carbon reduction functions.

[0015] Preferably, the slag powder in step 1 can be slag powder of grade S95 or above, and the silicate cement is ordinary silicate cement.

[0016] Preferably, the particle size of the slag powder, silicate cement, gypsum powder, fly ash and lime powder in step 1 should be micron-level.

[0017] Preferably, the mixing ratio of the mixture A and water in step 2 is preferably A:water=1:(40-60%) by mass percentage.

[0018] Preferably, the pore-forming agent in step three is preferably aluminum powder, the stirring intensity during mixing is preferably 20 to 100 r / min, and the foaming time during standing foaming is preferably 30 to 90 min.

[0019] Preferably, the size of the raw material C in step 4 is (20-40) cm×(20-40) cm×(50-80) cm, and the preferred size is 30 cm×30 cm×60 cm.

[0020] Preferably, the particle size of the S95 grade slag powder is less than 100 μm, and the content of inorganic substances such as calcium, silicon, and aluminum is greater than 30%;

[0021] Ordinary Portland cement has a particle size of less than 100 μm, a CaO content of 55-65%, and an Al2O3 mass ratio of 5-8%;

[0022] The particle size of raw gypsum powder is less than 100 μm, the CaO content is 30-35%, and the S content is 20-25%;

[0023] The fly ash particle size is less than 100 μm, and its SiO2 content is 53-60%, Al2O3 content is 25-30%, and f-CaO content is 8-10%;

[0024] The particle size of aluminum powder is less than 100 μm, and its Al content is greater than 90%;

[0025] The particle size of lime powder is less than 100 μm.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] (1) The composite silicate filter material with high-efficiency phosphorus removal function uses cement powder, fly ash from coal-fired power plants, and waste slag powder generated during blast furnace ironmaking as raw materials. Compared with commonly used filter materials such as clay ceramsite, the raw materials used in the present invention are low in cost and easy to obtain, the process is simple, and the requirements for production lines and equipment are low. At the same time, the present invention also has the effect of waste recycling.

[0028] (2) The composite silicate filter material with high-efficiency phosphorus removal function has extremely low soluble nitrogen and phosphorus components. After being immersed in water for more than 48 hours, the ammonia nitrogen and total phosphorus release are less than 0.0005 mg / g and 0.005 mg / g, and the COD release is 0. The actual application of the filter material in water treatment has no risk of nitrogen and phosphorus pollution.

[0029] (3) The composite silicate filter material with high-efficiency phosphorus removal function has a BET specific surface area greater than 50m2 / g, which is higher than conventional filter materials such as commercially available clay pellets, and has a high phosphorus adsorption and removal capacity, high removal efficiency, and good effluent quality. Under the condition that the influent phosphorus concentration is the first-class A standard (i.e., 0.5mg / L), after being treated with the filter material prepared by the present invention, the effluent phosphorus concentration is lower than 0.10mg / L, and the effluent water quality is good.

[0030] (4) The composite silicate filter material with efficient phosphorus removal function has a high calcium oxide content and has the functions of simultaneous calcium release and alkali supply. It can release calcium ions and alkalinity to generate stable hydroxy calcium phosphate (HAP) and other complexes with phosphate in water and fix them on the surface of the filter material, thereby achieving efficient and rapid phosphorus removal.

[0031] (5) The composite silicate filter material with efficient phosphorus removal function has a synergistic denitrification and carbon reduction effect while efficiently removing phosphorus. For sewage with a total phosphorus of about 0.1 mg / L, ammonia nitrogen of about 15 mg / L, and COD greater than 50 mg / L, after being treated with the filter material prepared by the present invention, the total phosphorus removal rate is greater than 50%, and the COD and ammonia nitrogen removal rates are greater than 50% and 34%, respectively.

[0032] (6) The composite silicate filter material with high-efficiency phosphorus removal function and its preparation method, as well as the filter material production process, are compatible with the current autoclaved aerated concrete manufacturing technology and can be produced using existing concrete production lines, effectively reducing production expenses and thereby significantly improving the market competitiveness of the product, thus bringing an innovative production model to the industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The present invention is further described below in conjunction with the accompanying drawings and embodiments:

[0034] Figure 1 is the BET diagram of the composite silicate filter material of the present invention;

[0035] Figure 2 FTIR graph of the composite silicate filter material of the present invention;

[0036] Figure 3 This is a SEM-EDS image of the composite silicate filter material of the present invention;

[0037] Figure 4 is the XRD diagram of the composite silicate filter material of the present invention;

[0038] Figure 5 This is a schematic diagram of Embodiment 2 of the present invention;

[0039] Figure 6 This is a schematic diagram of Embodiment 3 of the present invention. DETAILED DESCRIPTION

[0040] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present invention, but it cannot be understood as a limitation on the scope of protection of the present invention.

[0041] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0042] In the description of the present invention, "greater than", "less than", "exceed" etc. are understood as not including the number itself, and "above", "below", "within" etc. are understood as including the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0043] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0044] See also Figure 1-6 The present invention proposes a composite silicate filter material with high-efficiency phosphorus removal function, characterized in that it comprises the following raw materials: slag powder, silicate cement, gypsum powder, fly ash, lime powder;

[0045] Among them, the ratio of slag powder, silicate cement, gypsum powder, fly ash and lime powder is (32-38): (22-25): (3-8): (22-28): (5-10).

[0046] Embodiment 1:

[0047] Step 1, raw material preparation: select 38 slag powder, 25 silicate cement, 8 gypsum powder, 28 fly ash, and 10 lime powder and mix them evenly. The resulting mixture is recorded as A;

[0048] Among them, the slag powder can be selected from S95 grade or above slag powder, and the silicate cement is ordinary silicate cement;

[0049] Among them, the particle size of S95 grade slag powder is less than 100μm, and the content of inorganic substances such as calcium, silicon and aluminum is greater than 30%;

[0050] Ordinary Portland cement has a particle size of less than 100 μm, a CaO content of 55-65%, and an Al2O3 mass ratio of 5-8%;

[0051] The particle size of raw gypsum powder is less than 100 μm, the CaO content is 30-35%, and the S content is 20-25%;

[0052] The fly ash particle size is less than 100 μm, and its SiO2 content is 53-60%, Al2O3 content is 25-30%, and f-CaO content is 8-10%;

[0053] The particle size of aluminum powder is less than 100 μm, and its Al content is greater than 90%;

[0054] The particle size of lime powder is less than 100 μm;

[0055] Step 2, mixing the mixture A obtained in the first step with water to form a premix B;

[0056] Step 3, the premix B and the pore-forming agent are measured and mixed evenly according to the mass percentage of B: pore-forming agent = 1: 0.20%, injected into a steel mold, and allowed to stand for foaming;

[0057] Step 4, after standing and foaming, cutting by a cutting machine to obtain raw material C;

[0058] Step 5, steaming the raw material C at 800° C. for 10 hours and naturally cooling it to room temperature to obtain prefabricated material D;

[0059] Step six, after the prefabricated material D is crushed by a crusher, a screening machine is used to sort out the part with a particle size of 2 cm to 6 cm, thereby obtaining the composite silicate filter material prepared by the present invention with large-capacity and high-efficiency phosphorus removal and synergistic denitrification and carbon reduction functions.

[0060] The composite silicate filter material prepared in this embodiment has a BET specific surface area of ​​about 54.6 m2 / g and a strength of about 2.65 MPa. It contains a variety of phosphorus removal active ingredients such as CaCO3, CaO, Al2O3, and has abundant active adsorption sites such as carbonyl (C=O) and hydroxyl (-OH). When the influent phosphorus concentration is the first-level A standard (i.e., 0.5 mg / L), the filter material prepared by the present invention has a phosphorus removal rate of more than 80%, and the effluent phosphorus concentration is stably lower than 0.10 mg / L, and the effluent water quality is good.

[0061] Embodiment 2:

[0062] The filter material manufactured by the present invention is loaded into the baffled biofilter reactor shown in the figure below. The reactor has the dimensions of length × width × height = 500 mm × 120 mm × 250 mm, the effective volume of the reaction zone is 9.62 L, the filter material dosage is 2.8-3 kg, the artificially configured COD concentration is 50 mg / L, the ammonia nitrogen concentration is 5 mg / L, and the total phosphorus concentration is 0.5 mg / L. The sewage plant tail water is used as the influent, the influent flow rate is 6 L / d, and the hydraulic retention time is 24 hours. Figure 5 As shown;

[0063] After the baffled biofilter reactor has been running continuously for 38 days, the average removal rate of total phosphorus by the filter material prepared by the present invention can reach more than 85%, while the removal rate of ammonia nitrogen can reach 86% to 90%, and the removal rate of COD exceeds 50%. It can be seen from this embodiment that the composite silicate filter material prepared by the method provided by the present invention has a synergistic denitrification and carbon reduction effect while efficiently removing phosphorus.

[0064] Embodiment three:

[0065] The composite silicate filter material prepared by the present invention is used as filler for artificial wetlands and is used for deep phosphorus removal of tail water from actual sewage plants. The total design scale of an artificial wetland in Nanyang City, Henan Province is 40,000 m 3 / d, the project covers an area of ​​about 177 acres, of which the water area is about 65,000 square meters. The wetland has been in operation since 2023. The COD concentration of the influent is 11-13 mg / L, the ammonia nitrogen concentration is 0.18-0.56 mg / L, and the total phosphorus concentration is 0.15-0.17 mg / L. The wetland process design diagram is as follows Figure 6 As shown;

[0066] The composite silicate filter material prepared by the present invention is used in the porous medium ecological filter bed unit of the artificial wetland, and the filter material laying area is about 2750m 3 From June 2023 to date, after being treated in an artificial wetland using the composite silicate filter material prepared by the present invention, the average COD value of the wetland effluent was 9.86 mg / L, the average ammonia nitrogen value was 0.07 mg / L, and the average total phosphorus value was 0.07 mg / L, and the effluent water quality was good;

[0067] During the operation, the number of days with effluent total phosphorus less than 0.05 mg / L exceeded 34%, and the number of days with total phosphorus less than 0.1 mg / L exceeded 74%. Up to now, the total phosphorus concentration of effluent can be controlled below 0.2 mg / L, which is better than the Class III surface water discharge standard. It can be seen from this embodiment that the composite silicate filter material prepared by the method provided by the present invention has excellent phosphorus removal effect in the treatment of actual sewage plant tail water, and has the function of synergistic denitrification and carbon reduction, and has strong economic value and industrial application value.

[0068] Embodiment 4:

[0069] Step 1, raw material preparation: select 32 slag powder, 22 silicate cement, 3 gypsum powder, 22 fly ash, and 5 lime powder and mix them evenly. The resulting mixture is recorded as A;

[0070] Among them, the slag powder can be selected from S95 grade or above slag powder, and the silicate cement is ordinary silicate cement;

[0071] Among them, the particle size of S95 grade slag powder is less than 100μm, and the content of inorganic substances such as calcium, silicon and aluminum is greater than 30%;

[0072] Ordinary Portland cement has a particle size of less than 100 μm, a CaO content of 55-65%, and an Al2O3 mass ratio of 5-8%;

[0073] The particle size of raw gypsum powder is less than 100 μm, the CaO content is 30-35%, and the S content is 20-25%;

[0074] The fly ash particle size is less than 100 μm, and its SiO2 content is 53-60%, Al2O3 content is 25-30%, and f-CaO content is 8-10%;

[0075] The particle size of aluminum powder is less than 100 μm, and its Al content is greater than 90%;

[0076] The particle size of lime powder is less than 100 μm;

[0077] Step 2, mixing the mixture A obtained in the first step with water to form a premix B;

[0078] Step 3, the premix B and the pore-forming agent are measured and mixed evenly according to the mass percentage of B: pore-forming agent = 1: 0.20%, injected into a steel mold, and allowed to stand for foaming;

[0079] Step 4, after standing and foaming, cutting by a cutting machine to obtain raw material C;

[0080] Step 5, steaming the raw material C at 700° C. for 10 hours and naturally cooling it to room temperature to obtain prefabricated material D;

[0081] Step six, after the prefabricated material D is crushed by a crusher, a screening machine is used to sort out the part with a particle size of 2 cm to 6 cm, thereby obtaining the composite silicate filter material prepared by the present invention with large-capacity and high-efficiency phosphorus removal and synergistic denitrification and carbon reduction functions.

[0082] The composite silicate filter material prepared in this embodiment has a BET specific surface area of ​​about 54.6 m2 / g and a strength of about 2.65 MPa. It contains a variety of phosphorus removal active ingredients such as CaCO3, CaO, Al2O3, and has abundant active adsorption sites such as carbonyl (C=O) and hydroxyl (-OH). When the influent phosphorus concentration is the first-level A standard (i.e., 0.5 mg / L), the filter material prepared by the present invention has a phosphorus removal rate of more than 80%, and the effluent phosphorus concentration is stably lower than 0.10 mg / L, and the effluent water quality is good.

[0083] Embodiment five:

[0084] Step 1, raw material preparation: select 35 slag powder, 24 silicate cement, 5 gypsum powder, 24 fly ash, and 7 lime powder and mix them evenly. The resulting mixture is recorded as A;

[0085] Among them, the slag powder can be selected from S95 grade or above slag powder, and the silicate cement is ordinary silicate cement;

[0086] Among them, the particle size of S95 grade slag powder is less than 100μm, and the content of inorganic substances such as calcium, silicon and aluminum is greater than 30%;

[0087] Ordinary Portland cement has a particle size of less than 100 μm, a CaO content of 55-65%, and an Al2O3 mass ratio of 5-8%;

[0088] The particle size of raw gypsum powder is less than 100 μm, the CaO content is 30-35%, and the S content is 20-25%;

[0089] The fly ash particle size is less than 100 μm, and its SiO2 content is 53-60%, Al2O3 content is 25-30%, and f-CaO content is 8-10%;

[0090] The particle size of aluminum powder is less than 100 μm, and its Al content is greater than 90%;

[0091] The particle size of lime powder is less than 100 μm;

[0092] Step 2, mixing the mixture A obtained in the first step with water to form a premix B;

[0093] Step 3, the premix B and the pore-forming agent are measured and mixed evenly according to the mass percentage of B: pore-forming agent = 1: 0.20%, injected into a steel mold, and allowed to stand for foaming;

[0094] Step 4, after standing and foaming, cutting by a cutting machine to obtain raw material C;

[0095] Step 5, steaming the raw material C at 750° C. for 8 hours, and then naturally cooling it to room temperature to obtain a prefabricated material D;

[0096] Step six, after the prefabricated material D is crushed by a crusher, a screening machine is used to sort out the part with a particle size of 2 cm to 6 cm, thereby obtaining the composite silicate filter material prepared by the present invention with large-capacity and high-efficiency phosphorus removal and synergistic denitrification and carbon reduction functions.

[0097] The composite silicate filter material prepared in this embodiment has a BET specific surface area of ​​about 54.6 m2 / g and a strength of about 2.65 MPa. It contains a variety of phosphorus removal active ingredients such as CaCO3, CaO, Al2O3, and has abundant active adsorption sites such as carbonyl (C=O) and hydroxyl (-OH). When the influent phosphorus concentration is the first-level A standard (i.e., 0.5 mg / L), the filter material prepared by the present invention has a phosphorus removal rate of more than 80%, and the effluent phosphorus concentration is stably lower than 0.10 mg / L, and the effluent water quality is good.

[0098] The embodiments of the present invention are described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Various changes can be made within the knowledge scope of ordinary technicians in the technical field without departing from the purpose of the present invention.

Claims

1. A composite silicate filter material with high-efficiency phosphorus removal function, characterized in that; Including the following raw materials: Slag powder, Portland cement, gypsum powder, fly ash, lime powder; Among them, the ratio of slag powder, silicate cement, gypsum powder, fly ash and lime powder is (32-38): (22-25): (3-8): (22-28): (5-10).

2. A method for preparing a composite silicate filter material with high-efficiency phosphorus removal function, comprising the following steps: Step 1, raw material preparation: select slag powder, silicate cement, gypsum powder, fly ash, lime powder and mix them evenly, and the resulting mixture is recorded as A; Step 2, mixing the mixture A obtained in the first step with water to form a premix B; Step 3, the premix B and the pore-forming agent are measured and mixed evenly according to the mass percentage of B: pore-forming agent = 1: (0.05% to 0.20%), injected into a steel mold, and allowed to stand for foaming; Step 4, after standing and foaming, cutting by a cutting machine to obtain raw material C; Step 5, steaming the raw material C at 700-800° C. for 6-10 hours, and then naturally cooling it to room temperature to obtain a prefabricated material D; Step six, after the prefabricated material D is crushed by a crusher, a screening machine is used to sort out the part with a particle size of 2 cm to 6 cm, thereby obtaining the composite silicate filter material prepared by the present invention with large-capacity and high-efficiency phosphorus removal and synergistic denitrification and carbon reduction functions.

3. The method for preparing a composite silicate filter material with high-efficiency phosphorus removal function according to claim 2, characterized in that: The slag powder described in step 1 can be slag powder of grade S95 or above, and the silicate cement can be ordinary silicate cement.

4. The method for preparing a composite silicate filter material with high-efficiency phosphorus removal function according to claim 2, characterized in that: The particle sizes of the slag powder, silicate cement, gypsum powder, fly ash and lime powder in step 1 should be micrometer level.

5. The method for preparing a composite silicate filter material with high-efficiency phosphorus removal function according to claim 2, characterized in that: The mixing ratio of the mixture A and water in step 2 is preferably A:water=1:(40-60%) by mass percentage.

6. The method for preparing a composite silicate filter material with high-efficiency phosphorus removal function according to claim 2, characterized in that: The pore-forming agent in step 3 is preferably aluminum powder, the stirring intensity during mixing is preferably 20 to 100 r / min, and the foaming time during standing foaming is preferably 30 to 90 min.

7. The method for preparing a composite silicate filter material with high-efficiency phosphorus removal function according to claim 2, characterized in that: The size of the raw material C in step 4 is preferably (20-40) cm×(20-40) cm×(50-80) cm, and the preferred size is 30 cm×30 cm×60 cm.

8. The method for preparing a composite silicate filter material with high-efficiency phosphorus removal function according to claim 2, characterized in that: The particle size of the S95 grade slag powder is less than 100 μm, and the content of inorganic substances such as calcium, silicon, and aluminum is greater than 30%; Ordinary Portland cement has a particle size of less than 100 μm, a CaO content of 55-65%, and an Al2O3 mass ratio of 5-8%; The particle size of raw gypsum powder is less than 100 μm, the CaO content is 30-35%, and the S content is 20-25%; The fly ash particle size is less than 100 μm, and its SiO2 content is 53-60%, Al2O3 content is 25-30%, and f-CaO content is 8-10%; The particle size of aluminum powder is less than 100 μm, and its Al content is greater than 90%; The particle size of lime powder is less than 100 μm.

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