Preparation method of mn-ti supported solid waste-based catalytic ceramic membrane and application of ceramic membrane

Abstract

The present application belongs to the technical field of industrial solid waste resource utilization and environmental functional material, and particularly relates to a preparation method of Mn-Ti supported solid waste-based catalytic ceramic membrane and the ceramic membrane and application thereof. The present application takes bulk industrial solid wastes such as coal gangue, coal gasification slag and fly ash as main raw materials, first prepares Mn-Ti sol as catalyst precursor, and then obtains homogeneous integrated catalytic ceramic membrane with through-type gradient pore structure through the following steps: dosing and ball milling, extrusion molding, gradient temperature sintering, spraying membrane layer slurry, in-situ co-precipitation loading, drying and calcination. The obtained membrane has a pore size of 148-152 nm, and has high mechanical strength, high water flux and high catalytic activity, and can simultaneously realize physical interception and chemical catalytic degradation of pollutants, and is suitable for industrial wastewater advanced treatment, single scene or combined scene of flue gas multi-pollutant treatment. The present application greatly reduces the cost of raw materials and energy consumption, has high solid waste utilization rate, simple process and easy scaling.

Description

Technical Field

[0001] This invention belongs to the technical field of industrial solid waste resource utilization and environmental functional materials, specifically relating to a method for preparing a Mn-Ti supported solid waste-based catalytic ceramic membrane, as well as the ceramic membrane and its application. Background Technology

[0002] my country's coal and steel industries discharge over 1.5 billion tons of bulk industrial solid waste annually, including coal gangue, coal gasification slag, and fly ash. Traditional stockpiling and landfilling occupy land and easily cause pollution, making high-value utilization an urgent need. These solid wastes are rich in ceramic phase-forming components such as SiO2, Al2O3, Fe2O3, and CaO, possessing both natural porous structures and potential catalytic activity, making them suitable for low-cost functional ceramic preparation.

[0003] Inorganic ceramic membranes are highly resistant to high temperatures and corrosion, and possess high mechanical strength, leading to their rapid application in advanced industrial wastewater treatment, flue gas purification, and catalytic oxidation of recalcitrant organic matter. However, traditional ceramic membranes, using alumina, zirconium oxide, and silicon carbide as raw materials, suffer from high costs, high sintering temperatures, and high energy consumption, hindering large-scale adoption. Using bulk industrial solid waste as raw material can significantly reduce costs while simultaneously achieving solid waste reduction and recycling.

[0004] Current environmental governance needs are upgrading towards "separation + catalytic synergy," as traditional separation membranes struggle to simultaneously achieve pollutant retention and in-situ degradation. Coal gangue and coal gasification slag contain carbonaceous and porous silica-alumina phases, while fly ash is rich in transition metal oxides. Through component regulation and pore structure optimization, ceramic membranes can be endowed with catalytic activity, constructing integrated membrane materials suitable for advanced oxidation, ozone catalysis, and multi-pollutant flue gas treatment scenarios.

[0005] Patent CN202010143748.2 describes a solid waste-based ceramic catalytic membrane for antibiotic wastewater treatment, prepared by ball milling, drying, pressing, and sintering silicate tailings, bauxite, and metallurgical slag. The preparation method is simple, involving only a simple mixture of several substances, molding, and sintering, resulting in an incomplete pore structure and weak adsorption effect. It also contains few catalytic elements, leading to low pollutant removal rates. The product's simple structure and shape limit its application to water treatment. It struggles to achieve synergistic enhancement of separation and catalytic functions and cannot simultaneously treat both wastewater and flue gas. This invention addresses these shortcomings by utilizing large quantities of industrial solid waste and introducing in-situ Mn-Ti loading and gradient pore structure regulation, creating a fundamentally different approach. Summary of the Invention

[0006] To address the issues of low utilization rate of industrial solid waste, high cost of traditional ceramic membranes, lack of synergy between separation and catalysis functions, and limited application scenarios, this invention provides a method for preparing a Mn-Ti supported solid waste-based catalytic ceramic membrane and its application in dual scenarios, achieving "waste treatment with waste," reducing costs and energy consumption, endowing the membrane with dual functions of separation and catalysis, and adapting to the treatment needs of multiple scenarios.

[0007] To achieve the above objectives, the present invention employs the following technical solution: A method for preparing a Mn-Ti supported solid waste-based catalytic ceramic membrane includes the following steps: S1. Preparation of Mn-Ti catalyst precursor sol: Add glacial acetic acid to anhydrous ethanol and stir to obtain mixture A. Then add manganese nitrate solution and stir to obtain mixture B. Subsequently, add tetrabutyl titanate and stir until complete hydrolysis to obtain Mn-Ti sol.

[0008] S2. Preparation of solid waste-based ceramic intermediates: Coal gangue, coal gasification slag, and fly ash are used as the main raw materials. They are mixed with plastic clay, pore-forming agent, low-temperature binder, water, plasticizer, lubricant, water-reducing agent, and water-retaining agent and ball-milled. The mixture is then extruded and sintered at a gradient temperature to obtain a ceramic membrane substrate. Finally, a membrane slurry is sprayed onto the substrate to obtain the solid waste-based ceramic intermediate.

[0009] S3. Preparation of target catalytic ceramic membrane: The solid waste-based ceramic intermediate was immersed in Mn-Ti sol for in-situ co-precipitation and loading for 18-24 hours. After being taken out and dried, it was calcined to obtain Mn-Ti supported solid waste-based catalytic ceramic membrane.

[0010] Furthermore, in step S1, the molar ratio of anhydrous ethanol to glacial acetic acid is (20-26):(0.8-1.5), and the stirring time is 9-11 min.

[0011] Furthermore, in step S1, the manganese nitrate solution and the mixture A are mixed in the following mass ratios: manganese nitrate solution: 39-51 parts, mixture A: 0.8-1.5 parts, and the stirring time is 8-13 minutes.

[0012] Furthermore, in step S1, the mass ratio of tetrabutyl titanate to mixture B is as follows: tetrabutyl titanate: 14-25 parts, mixture B: 0.5-1.5 parts, and the stirring time is 25-33 minutes.

[0013] Furthermore, in step S2, all raw materials are proportioned by mass as follows: coal gangue: 19-40 parts, coal gasification slag: 9-20 parts, fly ash: 10-21 parts, plastic clay: 2.5-6 parts, pore-forming agent: 4.5-9 parts, low-temperature binder: 1.5-7 parts, water: 14-25 parts, plasticizer: 1-3.5 parts, lubricant: 3.5-8 parts, water-reducing agent: 0.2-1.5 parts, water-retaining agent: 1.5-4.5 parts; ball milling speed: 200-300 r / min, ball milling time: 4-6 h; molding pressure: 10-20 MPa; sintering adopts gradient heating: room temperature → 98-122℃ → 298-342℃ → 448-552℃ → 1098-1302℃.

[0014] The pore-forming agent is one or a mixture of starch, polyethylene glycol, or ammonium bicarbonate; the low-temperature binder is one or a mixture of polyvinyl alcohol or sodium carboxymethyl cellulose; the plasticizer is one or a mixture of glycerol or dibutyl phthalate; the lubricant is one or a mixture of stearic acid or paraffin emulsion; the water-reducing agent is one or a mixture of polycarboxylate-based water-reducing agents or naphthalene-based high-efficiency water-reducing agents; and the water-retaining agent is one or a mixture of hydroxyethyl cellulose or propylene glycol.

[0015] Furthermore, the film slurry mentioned in step S2 is prepared from nano-alumina powder, high-temperature binder, dispersant and deionized water; the spraying pressure is 0.38-0.42 MPa and the spraying thickness is 14.8-20.2 μm.

[0016] The high-temperature binder is one or a mixture of two of silica sol and alumina sol; the dispersant is one or a mixture of two of sodium hexametaphosphate and ammonium polyacrylate. The mass ratio of nano-alumina powder, high-temperature binder, dispersant and deionized water is as follows: nano-alumina powder: 100-120 parts, high-temperature binder: 5-9 parts, dispersant: 0.6-1.0 parts, deionized water: 230-350 parts.

[0017] Furthermore, in step S3, the drying temperature is 103–107°C; the calcination heating rate is 4.8–5.2°C / min; the calcination temperature is 548–552°C; and the holding time is 1.8–2.2 h.

[0018] Product characteristics of Mn-Ti supported solid waste-based catalytic ceramic membrane: The ceramic membrane has a homogeneous, integrated structure with a through-type gradient pore structure, a pore size of 148–152 nm, and a pure water flux of 0.8–1.4 m³ / s. 3 / (m 2 •h), with a flexural strength of 24.8–35.2 MPa, and the catalytically active component is Mn-Ti oxide with a particle size of 1.8–10.2 μm.

[0019] A dual-application model of a Mn-Ti supported solid waste-based catalytic ceramic membrane: applied to the deep treatment of industrial wastewater and the treatment of multiple pollutants in flue gas, simultaneously achieving physical interception and chemical catalytic degradation of pollutants.

[0020] In industrial wastewater treatment, it catalyzes ozone oxidation and Fenton reaction to degrade antibiotics, dyes, and phenolic organic compounds; in flue gas treatment, it integrates dust filtration with catalytic purification of VOCs and nitrogen oxides.

[0021] Compared with the prior art, the beneficial effects of the present invention are: 1. Using coal gangue, coal gasification slag, and fly ash as the main raw materials, it eliminates the need for high-purity ceramic raw materials, significantly reducing costs and achieving high-value utilization of solid waste.

[0022] 2. The method adopts Mn-Ti sol precursor + spraying + in-situ co-precipitation loading + gradient calcination to form a through gradient pore structure. The support, separation layer and catalytic center coexist in situ, avoiding interlayer shedding and loss of catalytic components. The structure is stable and the life is long.

[0023] 3. It has both physical interception and chemical catalysis functions, and can simultaneously complete separation and advanced oxidation degradation. It is suitable for multiple scenarios of wastewater and flue gas and has a wide range of applications.

[0024] 4. By relying on solid waste fluxing components to reduce sintering temperature, energy consumption and carbon emissions are reduced. The process is simple and easy to scale up. Attached Figure Description

[0025] Figure 1 This is a flowchart illustrating the preparation and application process of the present invention. Detailed Implementation

[0026] The present invention is further illustrated below by way of embodiments, but these embodiments are not intended to limit the invention to the scope of the embodiments described. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0027] Example 1:

[0028] Preparation of S1.Mn-Ti catalyst precursor sol: Take 21.5 mol of anhydrous ethanol and 0.9 mol of glacial acetic acid, mix and stir for 10 min to obtain a uniform and transparent mixture A; take 40 parts of manganese nitrate solution and 0.85 parts of mixture A, mix and stir for 10 min to obtain mixture B; take 15 parts of tetrabutyl titanate, slowly add it to 0.6 parts of mixture B, and continue stirring for 29 min until the system is completely hydrolyzed and there is no stratification or precipitation, thus preparing a stable and uniform Mn-Ti sol.

[0029] S2. Preparation of solid waste-based ceramic intermediates: The following raw materials were mixed in the following proportions by weight: 20 parts coal gangue, 10 parts coal gasification slag, 11 parts fly ash, 2.7 parts plastic clay, 4.8 parts starch pore-forming agent, 1.7 parts polyvinyl alcohol low-temperature binder, 16 parts deionized water, 1.4 parts glycerol plasticizer, 3.9 parts stearic acid lubricant, 0.4 parts polycarboxylate superplasticizer, and 1.8 parts hydroxyethyl cellulose water-retaining agent. All raw materials were fed into a ball mill, which was set to a speed of 230 r / min and continuously milled for 4.5 h to obtain a uniform and fine ceramic slurry.

[0030] The slurry is placed in a hydraulic molding machine and extruded under 11MPa pressure to obtain a ceramic green body; a gradient heating process is used for sintering: the temperature is raised from room temperature to 110℃ for drying, then raised to 330℃ to remove organic matter, then raised to 498℃ for pre-firing, and finally raised to 1198℃ for high-temperature sintering, and then naturally cooled to obtain a ceramic film substrate.

[0031] Preparation of the membrane slurry: 105 parts by weight of nano-alumina powder, 6 parts by weight of silica sol high-temperature binder, 0.65 parts by weight of sodium hexametaphosphate dispersant, and 235 parts by weight of deionized water were mixed and stirred evenly to prepare the spraying slurry. A pressure spraying process was adopted, with a spraying pressure of 0.40 MPa, to uniformly spray the slurry onto the ceramic membrane substrate, controlling the spraying thickness to 15.1 μm. After drying at room temperature, a solid waste-based ceramic intermediate was obtained.

[0032] S3. Preparation of the target catalytic ceramic membrane: The prepared solid waste-based ceramic intermediate was completely immersed in Mn-Ti sol and co-precipitated in situ for 18 hours. After being removed, it was placed in an oven at 103℃ for thorough drying. Then, it was transferred to a muffle furnace and heated to 550℃ at a heating rate of 4.85℃ / min. It was then calcined at this temperature for 1.85 hours and cooled to room temperature with the furnace to finally obtain the Mn-Ti supported solid waste-based catalytic ceramic membrane.

[0033] Product performance and application effects: The product features a homogeneous, integrated, through-type gradient pore structure with an average pore size of 150 nm, a pure water flux of 0.95 m³ / (m²•h), and a flexural strength of 25.8 MPa. The surface Mn-Ti oxide catalytic component has a particle size of 1.95~5.2 μm and is uniformly dispersed. This ceramic membrane can be applied to the deep treatment of industrial wastewater, efficiently degrading antibiotic wastewater through catalytic ozone oxidation and Fenton reaction. After treatment, the COD removal rate of the wastewater is ≥90%, the antibiotic removal rate is ≥98.5%, and the pollutant retention and degradation rates are excellent.

[0034] Example 2:

[0035] Preparation of S1.Mn-Ti catalyst precursor sol: Take 22 mol of anhydrous ethanol and 1.1 mol of glacial acetic acid, mix and stir for 12 min to obtain a uniform and transparent mixture A; take 45 parts of manganese nitrate solution and 1.0 part of mixture A, mix and stir for 11 min to obtain mixture B; take 20 parts of tetrabutyl titanate, slowly add it to 0.9 parts of mixture B, and continue stirring for 30 min until the system is completely hydrolyzed and there is no stratification or precipitation, thus preparing a stable and uniform Mn-Ti sol.

[0036] S2. Preparation of solid waste-based ceramic intermediates: The raw materials are formulated according to the following proportions by weight: 30 parts coal gangue, 15 parts coal gasification slag, 15 parts fly ash, 4 parts plastic clay, 7 parts polyethylene glycol pore-forming agent, 4 parts sodium carboxymethyl cellulose low-temperature binder, 20 parts deionized water, 2 parts dibutyl phthalate plasticizer, 5 parts paraffin emulsion lubricant, 0.8 parts naphthalene-based high-efficiency water-reducing agent, and 3 parts propylene glycol water-retaining agent. After mixing, the raw materials are ball-milled at 250 r / min for 5 h and then extruded under a pressure of 15 MPa.

[0037] Gradient temperature sintering process: room temperature → 110℃ → 320℃ → 500℃ → 1200℃, followed by segmented temperature holding sintering to obtain a ceramic membrane substrate. The membrane slurry was prepared with 109 parts nano-alumina, 7 parts aluminum sol, 0.8 parts ammonium polyacrylate, and 290 parts deionized water. The spraying pressure was 0.41 MPa, and the spraying thickness was 17.5 μm, thus obtaining a solid waste-based ceramic intermediate.

[0038] S3. Preparation of the target catalytic ceramic membrane: The ceramic intermediate was immersed in Mn-Ti sol for in-situ loading for 21 h and dried at 105 °C. The temperature was then increased to 550 °C at a rate of 5.0 °C / min and calcined for 2 h. After cooling, the finished catalytic ceramic membrane was obtained.

[0039] Product performance and application effects: The product has an average pore size of 150 nm, a pure water flux of 1.1 m³ / (m²·h), and a flexural strength of 30.0 MPa. The Mn-Ti oxide particles range from 3.5 to 7.8 μm in size, exhibiting stable catalytic activity. It is used for phenol-containing wastewater, combining physical interception with catalytic ozone oxidation, achieving a COD removal rate of ≥85% and a volatile phenol removal rate of ≥98%, ensuring effluent meets standards.

[0040] Example 3:

[0041] Preparation of S1.Mn-Ti catalyst precursor sol: Take 26 mol of anhydrous ethanol and 1.5 mol of glacial acetic acid, mix and stir for 11 min to obtain a uniform and transparent mixture A; take 51 parts of manganese nitrate solution and 1.5 parts of mixture A, mix and stir for 12 min to obtain mixture B; take 25 parts of tetrabutyl titanate, slowly add it to 1.4 parts of mixture B, and continue stirring for 31 min until the system is completely hydrolyzed and there is no stratification or precipitation, thus preparing a stable and uniform Mn-Ti sol.

[0042] S2. Preparation of solid waste-based ceramic intermediates: The raw materials are formulated in the following proportions by weight: 40 parts coal gangue, 20 parts coal gasification slag, 21 parts fly ash, 6 parts plastic clay, 9 parts ammonium bicarbonate pore-forming agent, 7 parts polyvinyl alcohol + sodium carboxymethyl cellulose composite low-temperature binder, 25 parts deionized water, 3.5 parts glycerol + dibutyl phthalate composite plasticizer, 8 parts stearic acid + paraffin emulsion composite lubricant, 1.5 parts polycarboxylic acid + naphthalene composite water-reducing agent, and 4.5 parts hydroxyethyl cellulose + propylene glycol composite water-retaining agent. After mixing, the raw materials are ball-milled at 300 rpm for 6 hours and then extruded under 20 MPa pressure.

[0043] Gradient temperature sintering process: room temperature → 122℃ → 342℃ → 552℃ → 1302℃, segmented temperature holding sintering to obtain a high-strength ceramic substrate. The film slurry was prepared with 111 parts nano-alumina, 9 parts silica sol + alumina sol composite high-temperature binder, 1.0 part sodium hexametaphosphate + ammonium polyacrylate composite dispersant, and 350 parts deionized water. The spraying pressure was 0.42 MPa, and the spraying thickness was 20.2 μm, thus obtaining a ceramic intermediate.

[0044] S3. Preparation of the target catalytic ceramic membrane: The intermediate was immersed in sol for in-situ loading for 24 hours and dried at 107℃; the temperature was increased to 552℃ at a rate of 5.2℃ / min, held for calcination for 2.2 hours, and then cooled to obtain the finished product.

[0045] Product performance and application effects: The product has an average pore size of 152 nm, a pure water flux of 1.4 m³ / (m²·h), and a flexural strength of 35.2 MPa, exhibiting excellent mechanical properties and high flux. The Mn-Ti oxide particles range from 5.0 to 10.2 μm in size, providing abundant catalytic active sites. It is used for flue gas treatment in steel plants, efficiently filtering dust (efficiency ≥99%), and degrading VOCs and NOx through catalytic active sites, achieving VOCs removal rates ≥90% and NOx removal rates ≥95%, thus realizing integrated treatment of multiple pollutants.

[0046] Example 4:

[0047] Preparation of S1.Mn-Ti catalyst precursor sol: Take 21 mol of anhydrous ethanol and 0.9 mol of glacial acetic acid, mix and stir for 9 min to obtain a uniform and transparent mixture A; take 41 parts of manganese nitrate solution and 0.9 parts of mixture A, mix and stir for 10 min to obtain mixture B; take 16 parts of tetrabutyl titanate, slowly add it to 0.7 parts of mixture B, and continue stirring for 27 min until the system is completely hydrolyzed to obtain Mn-Ti sol.

[0048] S2. Preparation of solid waste-based ceramic intermediates: The formula, by weight, consists of: 22 parts coal gangue, 11 parts coal gasification slag, 12 parts fly ash, 3 parts plastic clay, 5 parts starch + polyethylene glycol composite pore-forming agent, 2 parts polyvinyl alcohol low-temperature binder, 16 parts deionized water, 1.5 parts glycerol plasticizer, 4 parts stearic acid lubricant, 0.4 parts polycarboxylate superplasticizer, and 2 parts hydroxyethyl cellulose water-retaining agent. The mixture is ball-milled at 220 r / min for 4.5 h and then pressure-molded at 12 MPa.

[0049] Gradient sintering process: room temperature → 105℃ → 310℃ → 470℃ → 1150℃. Film slurry formulation: 115 parts nano-alumina, 6 parts silica sol, 0.7 parts sodium hexametaphosphate, 250 parts deionized water; spraying pressure 0.39MPa, spraying thickness 16μm, to obtain ceramic intermediate.

[0050] S3. Preparation of the target catalytic ceramic membrane: In-situ co-precipitation loading for 19 hours, drying at 104℃; heating to 549℃ at 4.9℃ / min, holding for 1.9 hours, calcination to form the product.

[0051] Product performance and application effects: The product has an average pore size of 149 nm, a pure water flux of 0.95 m³ / (m²·h), and a flexural strength of 26.5 MPa. The Mn-Ti oxide particles range from 2.0 to 6.0 μm in size and exhibit excellent dispersibility. It is used for flue gas treatment in coking plants, efficiently filtering dust (efficiency ≥98%), degrading VOCs and NOx, with VOCs removal rates ≥92% and NOx removal rates ≥96%, achieving integrated treatment of multiple pollutants.

[0052] Example 5:

[0053] Preparation of S1.Mn-Ti catalyst precursor sol: Take 24 mol of anhydrous ethanol and 1.3 mol of glacial acetic acid, mix and stir for 11.5 min to obtain a uniform and transparent mixture A; take 48 parts of manganese nitrate solution and 1.3 parts of mixture A, mix and stir for 11 min to obtain mixture B; take 22 parts of tetrabutyl titanate, slowly add it to 1.2 parts of mixture B, and continue stirring for 30.5 min until the system is completely hydrolyzed to obtain Mn-Ti sol.

[0054] S2. Preparation of solid waste-based ceramic intermediates: The formula, by weight, consists of: 35 parts coal gangue, 18 parts coal gasification slag, 18 parts fly ash, 5 parts plastic clay, 8 parts polyethylene glycol + ammonium bicarbonate composite pore-forming agent, 6 parts sodium carboxymethyl cellulose low-temperature binder, 22 parts deionized water, 3 parts dibutyl phthalate plasticizer, 7 parts paraffin emulsion lubricant, 1.2 parts naphthalene-based water-reducing agent, and 4 parts propylene glycol water-retaining agent. The mixture is ball-milled at 280 r / min for 5.5 h and then pressure-molded at 18 MPa.

[0055] Gradient sintering process: room temperature → 118℃ → 330℃ → 520℃ → 1250℃. Film slurry ratio: 113 parts nano alumina, 8 parts alumina sol, 0.9 parts ammonium polyacrylate, 320 parts deionized water; spraying pressure 0.41MPa, spraying thickness 19μm, to obtain ceramic intermediate.

[0056] S3. Preparation of the target catalytic ceramic membrane: The sample was subjected to in-situ loading for 23 hours and dried at 106℃; then heated to 551℃ at a rate of 5.1℃ / min and held for 2.1 hours before calcination to form the final product.

[0057] Product performance and application effects: The product has an average pore size of 151 nm, a pure water flux of 1.25 m³ / (m²·h), and a flexural strength of 32.8 MPa. The Mn-Ti oxide particle size ranges from 4.0 to 9.0 μm, exhibiting strong catalytic stability. Suitable for integrated industrial flue gas treatment scenarios, it achieves efficient dust filtration and simultaneous catalytic degradation of VOCs and nitrogen oxides. Dust filtration efficiency is ≥98.5%, VOCs removal rate is ≥93.2%, and NOx removal rate is ≥95.5%, achieving integrated flue gas purification with high treatment efficiency.

[0058] Example 6:

[0059] Preparation of S1.Mn-Ti catalyst precursor sol: Take 23 mol of anhydrous ethanol and 1.0 mol of glacial acetic acid, mix and stir for 12.5 min to obtain a uniform and transparent mixture A; take 43 parts of manganese nitrate solution and 1.0 part of mixture A, mix and stir for 10 min to obtain mixture B; take 18 parts of tetrabutyl titanate, slowly add it to 0.9 parts of mixture B, and continue stirring for 28.5 min until the system is completely hydrolyzed to obtain Mn-Ti sol.

[0060] S2. Preparation of solid waste-based ceramic intermediates: The formula, by weight, consists of: 28 parts coal gangue, 13 parts coal gasification slag, 14 parts fly ash, 3.5 parts plastic clay, 6 parts starch pore-forming agent, 3 parts composite low-temperature binder, 18 parts deionized water, 2.5 parts composite plasticizer, 6 parts composite lubricant, 0.6 parts composite water-reducing agent, and 2.5 parts composite water-retaining agent. The mixture is ball-milled at 240 r / min for 5 hours and then extruded under 14 MPa pressure.

[0061] Gradient sintering process: room temperature → 100℃ → 305℃ → 490℃ → 1180℃. Film slurry formulation: 116 parts nano-alumina, 7 parts silica sol + alumina sol composite binder, 0.8 parts composite dispersant, 280 parts deionized water; spraying pressure 0.40MPa, spraying thickness 17μm, to obtain ceramic intermediate.

[0062] S3. Preparation of the target catalytic ceramic membrane: The product was loaded with in-situ co-precipitate for 20 hours, dried at a constant temperature of 105℃, heated to 550℃ at a rate of 5.0℃ / min, held for 2 hours, and then calcined and naturally cooled to obtain the finished product.

[0063] Product performance and application effects: The product has an average pore size of 150 nm, a pure water flux of 1.1 m³ / (m²·h), and a flexural strength of 29.5 MPa, exhibiting balanced and stable performance across all aspects. The Mn-Ti oxide particles range from 2.5 to 7.5 μm, demonstrating excellent compatibility between catalytic activity and structural stability. It can be used in both wastewater and flue gas applications, efficiently treating recalcitrant industrial organic wastewater while simultaneously achieving integrated treatment of multiple pollutants in flue gas, demonstrating exceptional versatility.

Claims

1. A method for preparing a Mn-Ti supported solid waste-based catalytic ceramic membrane, characterized in that, Includes the following steps: S1. Preparation of Mn-Ti catalyst precursor sol: Add glacial acetic acid to anhydrous ethanol and stir to obtain mixture A. Then add manganese nitrate solution and stir to obtain mixture B. Subsequently, add tetrabutyl titanate and stir until complete hydrolysis to obtain Mn-Ti sol. S2. Preparation of solid waste-based ceramic intermediates: Coal gangue, coal gasification slag, and fly ash are used as the main raw materials. They are mixed with plastic clay, pore-forming agent, low-temperature binder, water, plasticizer, lubricant, water-reducing agent, and water-retaining agent and ball-milled. The mixture is then extruded and sintered at a gradient temperature to obtain a ceramic membrane substrate. Finally, a membrane slurry is sprayed onto the substrate to obtain the solid waste-based ceramic intermediate. S3. Preparation of target catalytic ceramic membrane: The solid waste-based ceramic intermediate was immersed in Mn-Ti sol for in-situ co-precipitation and loading for 18-24 hours. After being taken out and dried, it was calcined to obtain Mn-Ti supported solid waste-based catalytic ceramic membrane.

2. The method for preparing a Mn-Ti supported solid waste-based catalytic ceramic membrane according to claim 1, characterized in that, In step S1, the molar ratio of anhydrous ethanol to glacial acetic acid is (20-26):(0.8-1.5), and the stirring time is 9-11 min.

3. The method for preparing a Mn-Ti supported solid waste-based catalytic ceramic membrane according to claim 1, characterized in that, In step S1, the manganese nitrate solution and mixture A are mixed in the following mass ratios: manganese nitrate solution: 39-51 parts, mixture A: 0.8-1.5 parts, and the stirring time is 8-13 minutes.

4. The method for preparing a Mn-Ti supported solid waste-based catalytic ceramic membrane according to claim 1, characterized in that, In step S1, the mass ratio of tetrabutyl titanate to mixture B is as follows: tetrabutyl titanate: 14-25 parts, mixture B: 0.5-1.5 parts, and the stirring time is 25-33 minutes.

5. The method for preparing a Mn-Ti supported solid waste-based catalytic ceramic membrane according to claim 1, characterized in that, In step S2, all raw materials are proportioned by mass as follows: coal gangue: 19-40 parts, coal gasification slag: 9-20 parts, fly ash: 10-21 parts, plastic clay: 2.5-6 parts, pore-forming agent: 4.5-9 parts, low-temperature binder: 1.5-7 parts, water: 14-25 parts, plasticizer: 1-3.5 parts, lubricant: 3.5-8 parts, water-reducing agent: 0.2-1.5 parts, water-retaining agent: 1.5-4.5 parts; ball milling speed: 200-300 r / min, ball milling time: 4-6 h; molding pressure: 10-20 MPa; sintering adopts gradient heating: room temperature → 98-122℃ → 298-342℃ → 448-552℃ → 1098-1302℃.

6. The method for preparing the Mn-Ti supported solid waste-based catalytic ceramic membrane according to claim 5, characterized in that, The film slurry mentioned in step S2 is prepared from nano alumina powder, high-temperature binder, dispersant and deionized water; the spraying pressure is 0.38-0.42 MPa and the spraying thickness is 14.8-20.2 μm.

7. The method for preparing the Mn-Ti supported solid waste-based catalytic ceramic membrane according to claim 5, characterized in that, In step S3, the drying temperature is 103–107℃; the calcination heating rate is 4.8–5.2℃ / min; the calcination temperature is 548–552℃; and the holding time is 1.8–2.2h.

8. A Mn-Ti supported solid waste-based catalytic ceramic membrane, characterized in that: is prepared by the method of any one of claims 1-7; the ceramic membrane has a homogeneous integrated structure, a through-type gradient pore structure, a pore size of 148-152 nm, a pure water flux of 0.8-1.4 m 3 / (m 2 ·h), a bending strength of 24.8-35.2 MPa, a catalytically active component of Mn-Ti oxide, and a particle size of 1.8-10.2 μm.

9. An application of a Mn-Ti supported solid waste-based catalytic ceramic membrane, characterized in that: The ceramic membrane is prepared by the method described in any one of claims 1-7; it is applied to the deep treatment of industrial wastewater and the treatment of flue gas pollutants, and simultaneously achieves the physical interception and chemical catalytic degradation of pollutants.

10. The application of the Mn-Ti supported solid waste-based catalytic ceramic membrane according to claim 9, characterized in that, In industrial wastewater treatment, it catalyzes ozone oxidation and Fenton reaction to degrade antibiotics, dyes, and phenolic organic compounds; in flue gas treatment, it integrates dust filtration with catalytic purification of VOCs and nitrogen oxides.

Images