Method for preparing silicon-aluminum-based adsorbing material based on secondary aluminum ash and fly ash and application of silicon-aluminum-based adsorbing material
Through magnetic separation and water washing, fly ash and secondary aluminum ash were treated, and silicon-aluminum-based adsorption materials were prepared in combination with sintering, which solved the problem of resource utilization of secondary aluminum ash and fly ash, and achieved environmental pollution reduction and improved water treatment performance.
Patent Information
- Application Number
- CN202510515957.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-23
- Publication Date
- 2025-06-27
AI Technical Summary
The prior art is difficult to effectively utilize secondary aluminum ash and fly ash in resource utilization, resulting in environmental pollution and waste of resources.
The fly ash and secondary aluminum ash are treated by magnetic separation and water washing, and combined with sintering method to prepare silicon-aluminum-based adsorption materials for use in the field of water treatment.
The resource utilization of fly ash and secondary aluminum ash is realized, environmental pollution is reduced, and the prepared silicon-aluminum-based adsorption materials have good water treatment performance.
Smart Images
Figure CN120205086A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of industrial solid waste / hazardous waste resource utilization, and specifically relates to a method and application for preparing a silicon-aluminum-based adsorbent material from secondary aluminum ash and fly ash, which is applicable to the field of water treatment. Background Art
[0002] Fly ash is fine solid particles captured from the flue gas generated during the coal combustion process. It belongs to bulk industrial solid waste. Its chemical components are mainly SiO2, Al2O3, Fe2O3, CaO, SO3, Na2O, K2O, residual carbon, etc. It comes from the production and supply industries of electric power and heat, and other industries using coal-fired facilities. It has characteristics such as a porous structure and pozzolanic activity. The historical stockpile of fly ash in China has exceeded 3 billion tons and is increasing at a rate of about 150 million tons per year. The comprehensive utilization rate of fly ash in the country is less than 80%, which is concentrated in multiple fields such as building materials, environmental protection, agriculture, and industry.
[0003] Secondary aluminum ash is mainly an industrial waste generated during the process of electrolytic aluminum and recycled aluminum industries. Its chemical composition is relatively complex, mainly including Al2O3, AlN, aluminum carbide, SiO2, spinel (MgAl2O4), salt fluxes (NaCl, CaF2), etc. Among them, aluminum nitride will undergo a hydrolysis reaction when encountering water, releasing a large amount of ammonia gas, and it is listed in the "National Hazardous Waste List" in China. The annual output of secondary aluminum ash in China is about 2-3 million tons, and the resource utilization rate is only 20%-30%. The rest is still mainly landfilled or stored in stock. However, secondary aluminum ash contains toxic and harmful substances such as fluorides, cyanides, aluminum carbide, and aluminum nitride, which are likely to cause environmental pollution problems. At present, the resource utilization paths of secondary aluminum ash are few, mainly concentrated in the metallurgical field (calcium aluminate, aluminum-silicon-titanium alloy), environmental protection and chemical industry (poly aluminum chloride water purifying agent, industrial grade aluminum sulfate), flame retardant and refractory materials (aluminum hydroxide flame retardant, spinel refractory materials), and building materials (ceramsite / cement admixture), etc., but it is still not enough to quickly consume the accumulated secondary aluminum ash. Therefore, a fast and efficient method for treating secondary aluminum ash needs to be found. Summary of the Invention
[0004] In view of the problems of resource utilization and environmental problems of solid waste fly ash and secondary aluminum ash in the background art, the present invention provides a method and application for preparing a silicon-aluminum-based adsorbent material from secondary aluminum ash and fly ash. The process of the present invention realizes the preparation of a silicon-aluminum-based adsorbent material from two wastes, promotes the resource utilization of fly ash and secondary aluminum ash, not only can effectively reduce environmental pollution and production and operation pressure, but also the prepared silicon-aluminum-based adsorbent material can be directly used in the field of water treatment, and has good market application prospects.
[0005] To achieve the above object, the present invention specifically adopts the following technical solutions: The present invention provides a method for preparing a silicon-aluminum-based adsorbent material from secondary aluminum ash and fly ash, comprising the following steps: Step 1: Take fly ash, perform magnetic separation and iron removal, and obtain iron-removed fly ash for standby; Step 2: Take secondary aluminum ash, wash and soak it with water, and then calcine it to obtain desalted secondary aluminum ash; Step 3: Mix the iron-removed fly ash obtained in Step 1 with the desalted secondary aluminum ash obtained in Step 2, add a binder and a burnout substance, fully mix and press them into a green body, and finally obtain the silicon-aluminum-based adsorbent material through calcination.
[0006] Further, before magnetic iron removal of the fly ash in Step 1, it needs to be ground to 200-300 meshes, and the magnetic field strength for magnetic separation and iron removal is not less than 0.8 T; the iron oxide content in the obtained iron-removed fly ash does not exceed 2 wt%.
[0007] Further, the water washing and soaking in Step 2 means taking secondary aluminum ash, adding water to soak and stirring for 24-48 h until neutral, and then drying at 105-120 °C and entering the calcination process.
[0008] Further, the calcination treatment temperature in Step 2 is 600-850 °C, and the time is 2-4 h.
[0009] Further, the mass ratio of the iron-removed fly ash to the desalted secondary aluminum ash in Step 3 is (35-39):(43-49), and they are mixed according to the molar ratio of Al2O3:SiO2 of (1.5-1.8):1.
[0010] Further, the binder in Step 3 is polyvinyl alcohol, and the burnout substance includes at least one of polystyrene balls, carbon black, and corn starch.
[0011] Further, in Step 3, the addition amounts of each raw material by weight are: 35-39 parts of iron-removed fly ash, 43-49 parts of desalted secondary aluminum ash, 3-5 parts of binder, and 8-12 parts of burnout substance.
[0012] Further, the calcination temperature of the green body in Step 3 is 1100-1300 °C, the heating rate does not exceed 10 °C / min, and the holding time is 1-4 h.
[0013] The present invention also provides the application of the silicon-aluminum-based adsorbent material prepared by the above method in the field of water treatment, including but not limited to carriers, adsorbent materials, and floating island ecological floating bed substrates.
[0014] Compared with the prior art, the beneficial effects of the present invention are: 1. In the product of the lightweight silicon-aluminum-based adsorbent material of the present invention, secondary aluminum ash in the raw materials is a hazardous waste, and fly ash is an industrial solid waste. Both are recycled and reused for the resource recovery of industrial waste, which conforms to the strategic concept of circular economy and green development.
[0015] 2. The preparation process of the aluminosilicate-based adsorbent material of the present invention adopts the sintering method, and there are relatively mature processes for reference, with strong industrial feasibility.
[0016] 3. The lightweight aluminosilicate-based adsorbent material product prepared by the present invention has the characteristics of low bulk density (0.90 - 1.10 g / cm 3 ), large apparent porosity (58.0% - 62.0%), high normal temperature compressive strength (3.85 - 4.15 MPa), and insoluble in water (mullite and sodium aluminosilicate).
[0017] 4. The lightweight aluminosilicate-based adsorbent material product prepared by the present invention can be made into various shapes suitable for water treatment applications, such as granular, spherical, square, etc., and is used as a carrier for heavy metal wastewater treatment, municipal sewage and industrial wastewater biochemical treatment, and a matrix for floating island ecological floating beds in basin treatment. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 It is a process flow chart for the preparation process of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0019] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Those not specified in the embodiments are carried out according to the conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments not specified in the manufacturer are all conventional products that can be obtained through commercial purchase.
[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field of the present invention. The terms used in the description of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.
[0021] Example 1 A method for preparing an aluminosilicate-based adsorbent material based on secondary aluminum ash and fly ash, comprising: 1. Take the original fly ash and grind it thoroughly to 200 meshes with a ball mill, and use a magnetic separator (magnetic field intensity 1T) for magnetic separation to separate Fe2O3 (content reduced to 2.0 wt%) to obtain iron-removed fly ash; 2. Take the original secondary aluminum ash, soak it in water, stir for 36 h until neutral, dry it to constant weight at 105 °C, and then transfer it to a muffle furnace and calcine it at 800 °C for 2 h to obtain desalted secondary aluminum ash; 3. Mix 39 parts by weight of the iron-removed fly ash obtained in step 1 with 46 parts by weight of the desalted secondary aluminum ash obtained in step 2 (the molar ratio of Al2O3:SiO2 is 1.65:1), then add 3 parts of polyvinyl alcohol and 9 parts of corn starch, mix well and press into shape to obtain a product preform; 4. Calcinate the product preform at a heating rate of 10 °C / min, heat up to 1100 °C and keep it at a constant temperature for 2 h, and then naturally cool it to room temperature to obtain the silicon-aluminum-based adsorbent material.
[0022] Example 2 A method for preparing a silicon-aluminum-based adsorbent material based on secondary aluminum ash and fly ash, comprising: 1. Take the original fly ash and grind it thoroughly to 200 meshes with a ball mill, and use a magnetic separator (magnetic field strength 1 T) to magnetically separate Fe2O3 (the content is reduced to 2.0 wt%) to obtain iron-removed fly ash; 2. Take the original secondary aluminum ash, soak it in water and stir for 36 h until neutral, dry it to a constant weight at 105 °C, then transfer it to a muffle furnace and calcine it at 800 °C for 2 h to obtain desalted secondary aluminum ash; 3. Mix 36 parts by weight of the iron-removed fly ash obtained in step 1 with 49 parts by weight of the desalted secondary aluminum ash obtained in step 2 (the molar ratio of Al2O3:SiO2 is 1.75:1), then add 3 parts of polyvinyl alcohol and 9 parts of corn starch, mix well and press into shape to obtain a product preform; 4. Calcinate the product preform at a heating rate of 10 °C / min, heat up to 1250 °C and keep it at a constant temperature for 2 h, and then naturally cool it to room temperature to obtain the silicon-aluminum-based adsorbent material.
[0023] Comparative Example 1 A method for preparing a silicon-aluminum-based adsorbent material based on secondary aluminum ash and fly ash, comprising: 1. Take the original fly ash and grind it thoroughly to 200 meshes with a ball mill; 2. Take the original secondary aluminum ash, soak it in water and stir for 36 h until neutral, dry it to a constant weight at 105 °C, then transfer it to a muffle furnace and calcine it at 800 °C for 2 h to obtain desalted secondary aluminum ash; 3. Mix 39 parts by weight of the fly ash obtained in step 1 with 44 parts by weight of the desalted secondary aluminum ash obtained in step 2 (the molar ratio of Al2O3:SiO2 is 1.65:1), then add 3 parts of polyvinyl alcohol and 9 parts of corn starch, mix well and press into shape to obtain a product preform; 4. Calcinate the product preform at a heating rate of 10 °C / min, heat up to 1100 °C and keep it at a constant temperature for 2 h, and then naturally cool it to room temperature to obtain the silicon-aluminum-based adsorbent material.
[0024] Comparative Example 2 A method for preparing a silicon-aluminum-based adsorbent material from secondary aluminum ash and fly ash, comprising: 1. Take the original fly ash and grind it thoroughly with a ball mill to 200 mesh, and use a magnetic separator (magnetic field strength 1 T) to magnetically separate Fe2O3 (content reduced to 2.0 wt%) to obtain iron-removed fly ash; 2. Take the original secondary aluminum ash, soak it in water, stir for 36 h until neutral, and dry it to constant weight at 105 °C; 3. Mix 38 parts of the iron-removed fly ash obtained in step 1 with 46 parts of the desalted secondary aluminum ash obtained in step 2 by weight (the molar ratio of Al2O3:SiO2 is 1.65:1), then add 3 parts of polyvinyl alcohol and 9 parts of corn starch, mix well and press into shape to obtain a product preform; 4. Calcinate the product preform at a heating rate of 10 °C / min, heat up to 1100 °C and keep it at a constant temperature for 2 h, and then naturally cool to room temperature to obtain the silicon-aluminum-based adsorbent material.
[0025] Comparative Example 3 A method for preparing a silicon-aluminum-based adsorbent material from secondary aluminum ash and fly ash, comprising: 1. Take the original fly ash and grind it thoroughly with a ball mill to 200 mesh, and use a magnetic separator (magnetic field strength 1 T) to magnetically separate Fe2O3 (content reduced to 2.0 wt%) to obtain iron-removed fly ash; 2. Take the original secondary aluminum ash, soak it in water, stir for 36 h until neutral, dry it to constant weight at 105 °C, and then transfer it to a muffle furnace and roast it at 800 °C for 2 h to obtain desalted secondary aluminum ash; 3. Mix 30 parts of the iron-removed fly ash obtained in step 1 with 55 parts of the desalted secondary aluminum ash obtained in step 2 by weight (the molar ratio of Al2O3:SiO2 is 1.95:1), then add 3 parts of polyvinyl alcohol and 9 parts of corn starch, mix well and press into shape to obtain a product preform; 4. Calcinate the product preform at a heating rate of 10 °C / min, heat up to 1100 °C and keep it at a constant temperature for 2 h, and then naturally cool to room temperature to obtain the silicon-aluminum-based adsorbent material.
[0026] 3. Mix 30 parts of the iron-removed fly ash obtained in step 1 with 55 parts of the desalted secondary aluminum ash obtained in step 2 by weight, then add 3 parts of polyvinyl alcohol and 9 parts of the pore-forming agent corn starch, mix well and press into shape to obtain a product preform; 4. Calcinate the product preform at a heating rate of 10 °C / min, heat up to 1100 °C and keep it at a constant temperature for 2 h, and then naturally cool to room temperature to obtain the silicon-aluminum-based adsorbent material.
[0027] Detection and Analysis Perform physical index detection and copper-containing wastewater adsorption experiments on the adsorbent material samples prepared in the above examples and comparative examples.
[0028] Prepare copper-containing wastewater with a concentration of 100 mg / L (pH is about 5.5). Add the silicon-aluminum-based adsorbent material into the copper-containing wastewater solution (the addition amount is 1.5 g / L), and carry out adsorption in a constant-temperature oscillator. Measure and analyze the residual copper ion concentration in the aqueous phase at regular intervals, and stir until the adsorption equilibrium is reached. Calculate the removal rate η and the adsorption capacity Q using the following formulas.
[0029] η = (C0 - C e ) / C0 Q = (C0 - C e ) * V / m Among them, η is the removal rate of the copper-containing wastewater by the silicon-aluminum-based adsorbent material at equilibrium, %; Q is the adsorption capacity of the silicon-aluminum-based adsorbent material at equilibrium, mg / g; C0 and C e are the initial concentration (mg / L) and the equilibrium concentration (mg / L) of copper ions in the aqueous phase respectively; m is the mass of the silicon-aluminum-based adsorbent material, g; V is the volume of the liquid phase, L.
[0030] Table 1 Process conditions for each group
[0031] Table 2 Detection results of the physical properties and adsorption capacity of the silicon-aluminum-based adsorbent materials for each group
[0032] The larger the adsorption capacity, the better the adsorption effect of the silicon-aluminum-based adsorbent material. From the detection results of Examples 1-2, it can be seen that the lightweight silicon-aluminum-based adsorbent material product prepared by the present invention has the advantages of low bulk density, large apparent porosity, and high normal temperature compressive strength, and can meet the application requirements of water treatment. By comparing the data of Comparative Examples 1-3, it can be seen that the iron content in fly ash and the sodium oxide content in secondary aluminum ash will affect the normal temperature compressive strength and adsorption performance of the silicon-aluminum-based adsorbent material to varying degrees; at the same time, when the aluminum-silicon ratio in the raw materials increases, mullite is easily formed during the high-temperature roasting process, increasing the normal temperature compressive strength of the silicon-aluminum-based adsorbent material, but greatly reducing the adsorption performance.
[0033] The embodiments described above only represent several preferred embodiments of the present invention. The description is relatively specific and detailed, but it does not limit the present invention. It should be noted that for those skilled in the art, the present invention can have various changes and modifications. Any modifications, equivalent replacements, improvements, etc. made within the concept and principle of the present invention should be included within the protection scope of the present invention.
Claims
1. A method for preparing silicon-aluminum based adsorption material based on secondary aluminum ash and fly ash, characterized in that: The steps include: Step 1: Take fly ash, subject it to magnetic separation and iron removal, and obtain iron-removed fly ash for standby use; Step 2: washing and soaking the secondary aluminum ash, and then roasting to obtain desalted secondary aluminum ash; Step three: Mix the iron-removed fly ash obtained in step one with the desalted secondary aluminum ash obtained in step two, add a binder and burnt materials, mix thoroughly, press and form a green body, and finally calcine to obtain a silicon-aluminum-based adsorption material.
2. The method for preparing silicon-aluminum based adsorption material based on secondary aluminum ash and fly ash according to claim 1, characterized in that: In step 1, the fly ash needs to be ground to 200-300 mesh before magnetic iron removal, and the magnetic field intensity of magnetic iron removal is not less than 0.8T; the iron oxide content in the obtained iron-removed fly ash does not exceed 2 wt%.
3. The method for preparing silicon-aluminum based adsorption material based on secondary aluminum ash and fly ash according to claim 1, characterized in that: The water washing and soaking in step 2 is to soak the secondary aluminum ash in water and stir it for 24-48 hours until it becomes neutral, and then dry it at 105-120° C. before entering the roasting process.
4. The method for preparing silicon-aluminum based adsorption material based on secondary aluminum ash and fly ash according to claim 1, characterized in that: The calcination treatment temperature in step 2 is 600-850° C. and the calcination time is 2-4 h.
5. The method for preparing silicon-aluminum based adsorption material based on secondary aluminum ash and fly ash according to claim 1, characterized in that: In step 3, the mass ratio of iron-removing fly ash to desalted secondary aluminum ash is (35-39):(43-49), and they are mixed according to the molar ratio of Al2O3:SiO2 (1.5-1.8):
1.
6. The method for preparing silicon-aluminum based adsorption material based on secondary aluminum ash and fly ash according to claim 1, characterized in that: In step 3, the binder is polyvinyl alcohol, and the burnt material includes at least one of polystyrene balls, carbon black, and corn starch.
7. The method for preparing silicon-aluminum based adsorption material based on secondary aluminum ash and fly ash according to claim 1, characterized in that: In step three, the added amount of each raw material is calculated by weight: 35-39 parts of iron-removing fly ash, 43-49 parts of desalted secondary aluminum ash, 3-5 parts of binder, and 8-12 parts of burnt materials.
8. The method for preparing silicon-aluminum based adsorption material based on secondary aluminum ash and fly ash according to claim 1, characterized in that: In step 3, the calcination temperature of the green body is 1100-1300°C, the heating rate does not exceed 10°C / min, and the holding time is 1-4 h.
9. The silicon-aluminum based adsorption material prepared by the method according to any one of claims 1 to 8.
10. Use of the silicon-aluminum based adsorption material as claimed in claim 9 in the field of water treatment.