Iron-aluminum-manganese-based porous metal film as well as preparation method and application thereof

Abstract

The invention discloses an iron-aluminum-manganese-based porous metal film as well as a preparation method and application thereof, and belongs to the technical field of primary flue gas purification filter materials of converters. The method comprises the following steps that metal powder, a binding agent, a dispersing agent, a defoaming agent, a flatting agent and pure water are evenly mixed to form metal mixed slurry; wherein the metal powder is Fe, Al and Mn series metal powder or a composition of the Fe, Al and Mn series metal powder and other additive element powder, and the other additive element powder is one or more element powder of Mo, Si, Y, Cr, Cu, Ce, Ni and Co; and coating the metal mixed slurry on the surface of a metal base net by adopting a blade coating or roller coating mode to form a membrane blank, then drying, degreasing and sintering to obtain the iron-aluminum-manganese-based porous metal membrane. The iron-aluminum-manganese-based porous metal film prepared through the preparation method serves as a filter material to be applied to primary flue gas filtration of a converter, and efficient purification of primary flue gas of the converter and long-life recycling of the filter material are achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of converter primary flue gas purification filter materials, and particularly relates to an iron-aluminum-manganese-based porous metal membrane and a preparation method and application thereof. Background Art

[0002] Converter steelmaking accounts for approximately 90% of steelmaking production. Converter flue gas contains a large amount of waste heat and chemical energy, and is characterized by intermittent emissions, high dust concentration, and flammability and explosion. Currently, companies generally use the OG process or LT process to cool the flue gas by spraying and then recover it. Among them, the spraying method can effectively avoid flue gas explosions, but it also causes direct waste of medium and low temperature waste heat resources. To this end, a further technical solution adopts a fully dry sensible heat recovery technology. This technology first uses a special radial heat pipe heat exchange device to efficiently recover the sensible heat in the primary flue gas, and then purifies the flue gas and recovers the coal gas through high-efficiency dust removal equipment.

[0003] The main components of converter primary flue gas are oxygen, carbon oxides, sulfur oxides, and acidic gases such as H2S, HCl, and HF. Dust includes iron oxides, carbon, alkali metal oxides, SiO2, and P2O5. This flue gas has three key characteristics that pose severe challenges to subsequent filtration processes: the average dust content of converter primary flue gas is high, with an average dust content of 80-150g / m 3 , can reach 200g / m3 in the middle of blowing or at the moment of adding material 3 The flue gas filtration temperature is high. Since dust (especially iron, carbon and other components) may undergo an exothermic oxidation reaction during the filtration process, the actual filtration temperature is much higher than the original flue gas temperature. The flue gas flow, temperature, composition and dust content all change dramatically with the converter smelting cycle.

[0004] Currently, the main methods for filtering converter primary flue gas include electrostatic precipitators (ESPs) and bag filters. ESPs, however, have significant limitations: high investment and operating costs, and operational stability is easily affected by drastic fluctuations in flue gas conditions. They are inefficient in capturing fine dust (especially particles <20μm in size), and pose a significant explosion hazard when filtering flue gas containing high concentrations of flammable and explosive gases (such as CO) and fine dust.

[0005] To overcome the shortcomings of electrostatic precipitators, some existing solutions have replaced them with metal bag filters in the hope of achieving better dust removal performance. Existing solutions primarily include stainless steel-based porous metal membranes, Fe-Al alloy porous metal membranes, and stainless steel fiber filter bags. However, these materials perform poorly in the operating conditions of converter primary flue gas, characterized by high temperatures, high dust concentrations, and the presence of various oxidizing and acidic corrosive gases such as O2, SO2, H2S, HCl, and HF. These conditions cause severe corrosion and thermal stress cracking of the filter material, making it difficult to maintain stable and long-term operation and significantly shortening its service life.

[0006] For example, the Chinese invention patent with publication number CN111359451A discloses an Fe-Al metal membrane and its preparation method, which relates to the technical field related to gas-solid separation under high-temperature, low-pressure conditions. It mainly addresses the defects of traditional metal filter elements in the prior art, such as high filtration resistance and low flux under low-pressure working environments. However, the corrosion resistance of this material is still insufficient under the unique working conditions of converter primary flue gas, and it is still prone to failure forms such as holes and cracks, which ultimately lead to reduced filtration efficiency and increased maintenance costs. And the Chinese invention patent with publication number CN117982989A discloses a stainless steel fiber felt and its preparation method. However, the stainless steel material used in it has limited long-term service capacity in the high-temperature, oxygen-rich, sulfur-containing and halogen-containing acidic composite corrosion environment of the above-mentioned converter flue gas, and also faces problems such as rapid breakage, aging, and cracking. This forces the system to frequently replace the filter material, which not only reduces operating efficiency but also significantly increases maintenance costs. Summary of the Invention

[0007] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide an iron-aluminum-manganese (Fe-Al-Mn) based porous metal membrane and its preparation method and application, so as to achieve efficient purification of converter primary flue gas and long-life recycling of filter materials.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions: In one aspect, the present invention provides a method for preparing an iron-aluminum-manganese-based porous metal film, comprising the following steps: S1: uniformly mixing metal powder, binder, dispersant, defoamer, leveling agent and pure water to form a metal mixed slurry; wherein the metal powder is Fe, Al, Mn series metal powder or a combination of Fe, Al, Mn series metal powder and other added element powders, and the other added element powders are one or more element powders of Mo, Si, Y, Cr, Cu, Ce, Ni and Co; S2: The metal mixed slurry is applied on the surface of the metal base mesh by blade coating or roller coating to form a membrane embryo, which is then dried, degreased and sintered to obtain an iron-aluminum-manganese based porous metal membrane.

[0009] In one embodiment, the metal mixture slurry includes, by weight, 70-90 parts of metal powder, 1-10 parts of binder, 0.05-5 parts of dispersant, 0-1 parts of defoaming agent, 0.05-1 parts of leveling agent, and the balance is pure water.

[0010] In one embodiment, the metal mixture slurry includes, by weight, 70-90 parts of metal powder, 1-5 parts of binder, 0.05-3 parts of dispersant, 0-0.5 parts of defoaming agent, 0.05-1 parts of leveling agent, and the balance is pure water.

[0011] In one embodiment, the Fe, Al, and Mn metal powders are Fe element powder, Al element powder or FeAl alloy powder, and Mn element powder; the particle size of the Fe, Al, and Mn metal powders and other additive element powders is 5 to 100 μm; when the metal powder is Fe, Al, and Mn metal powder, the Al element accounts for 8 to 15% of the total weight of the Fe element, Al element, and Mn element, the Mn element accounts for 3 to 12% of the total weight of the Fe element, Al element, and Mn element, and the balance is Fe element; when the metal powder is a combination of Fe, Al, and Mn metal powders and other additive element powders, the sum of the weights of the three elements Fe, Al, and Mn in the metal powder accounts for more than 90% of the total weight of the metal powder, and the balance is other additive element powders.

[0012] In one embodiment, the particle size of the Fe, Al, Mn-based metal powder and other added element powder is 5-30 μm; when the metal powder is Fe, Al, Mn-based metal powder, the Al element accounts for 10-15% of the total weight of the Fe element, Al element and Mn element, the Mn element accounts for 3-8% of the total weight of the Fe element, Al element and Mn element, and the balance is Fe element.

[0013] In one embodiment, the drying temperature is 60-90°C and the drying time is 1-3 hours; the debinding and sintering process is completed in a vacuum or atmosphere sintering furnace at one time, and the specific steps are as follows: the sintering temperature is increased from room temperature to 350-450°C at a heating rate of 3-15°C / min, and kept at this temperature for 60-300 minutes; the sintering temperature is increased to 550-650°C at a heating rate of 2-15°C / min, and kept at this temperature for 60-300 minutes; 0 minutes; raise the sintering temperature to 850~950℃, the heating rate is 1~15℃ / min, and keep it at this temperature for 60~120 minutes; raise the sintering temperature to 1000℃~1100℃, the heating rate is 1~10℃ / min, and keep it at this temperature for 60~420 minutes; raise the sintering temperature to 1200℃~1300℃, the heating rate is 1~5℃ / min, and keep it at this temperature for 120~420 minutes. Cool with the furnace after sintering.

[0014] In one embodiment, the binder includes one or more of polyvinyl alcohol, polyethylene glycol, glycerol, methyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose and sodium carboxymethyl cellulose; the dispersant is one or more of sodium dodecylbenzene sulfonate, sodium stearate, sodium hexametaphosphate, sodium tripolyphosphate, and carboxymethyl cellulose; the leveling agent is one or both of TEGO Glide 410 and TEGO Wet 270; and the defoamer is BYK-052.

[0015] The present invention also provides an iron-aluminum-manganese based porous metal membrane prepared according to the above-mentioned preparation method of the iron-aluminum-manganese based porous metal membrane, comprising a sintered Fe-Al-Mn based metal powder film layer and a metal base mesh; wherein the sintered Fe-Al-Mn based metal powder film layer is located on the metal base mesh.

[0016] In one embodiment, the mesh type of the metal base mesh is a stainless steel mesh or a perforated mesh; the material of the metal base mesh is selected from one or more of 304 stainless steel, 316L stainless steel, 310s stainless steel, Fe-Al alloy, and FeCrAl alloy; the mesh number range of the metal base mesh is 20~100 mesh; when the mesh type of the metal base mesh is a perforated mesh, the short pitch of the mesh is 0.5~3.0 mm, and the long pitch of the mesh is 0.5~5.0 mm.

[0017] The present invention also provides the use of the iron-aluminum-manganese-based porous metal membrane prepared by the above-mentioned preparation method of the iron-aluminum-manganese-based porous metal membrane as a filter material in the primary flue gas filtration of the converter.

[0018] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a method for preparing an iron-aluminum-manganese-based porous metal film. On the basis of the excellent high-temperature oxidation resistance of FeAl alloy, the toughness and high-temperature creep resistance are improved by adding Mn elements, and the corrosion resistance under S-containing gas and acidic gas working conditions is improved. Furthermore, other element powders, such as Mo, Si, Y, Cr, Cu, Ce, Ni, Co, etc., can be used for small-scale doping to improve the high-temperature creep resistance of the Fe-Al-Mn-based porous metal film, enhance the passivation ability of the material in SO2-containing flue gas, reduce the tendency of pitting corrosion, and improve the backwash cleaning performance. Metal mesh or punched mesh is selected as the supporting layer to provide excellent mechanical strength and supporting performance. The metal film layer is coated by scraping or roller coating, which has high production efficiency and is convenient for controlling the thickness of the film layer.

[0019] This invention provides an iron-aluminum-manganese (Fe-Al-Mn)-based porous metal membrane for use as a filter material in converter primary flue gas filtration. This Fe-Al-Mn alloy exhibits excellent tensile strength and acid corrosion resistance as a metal membrane material. Furthermore, it maintains high filtration efficiency and low differential pressure over long periods of operation. Samples optimized with specific alloying elements exhibit significantly improved overall performance. DETAILED DESCRIPTION

[0020] To facilitate understanding of the features and effects of the present invention by those skilled in the art, the following provides a general description and definition of the terms and expressions used in the specification and claims. Unless otherwise indicated, all technical and scientific terms used herein have the ordinary meanings as understood by those skilled in the art regarding the present invention. In the event of conflict, the definitions in this specification shall prevail.

[0021] The present invention provides an iron-aluminum-manganese (Fe-Al-Mn) based porous metal film, a preparation method and an application thereof.

[0022] In one aspect, the present invention provides a method for preparing an iron-aluminum-manganese-based porous metal film, comprising the following steps: S1: uniformly mixing metal powder, binder, dispersant, defoamer, leveling agent and pure water to form a metal mixed slurry; wherein the metal powder is Fe, Al, Mn series metal powder or a combination of Fe, Al, Mn series metal powder and other added element powders, and the other added element powders are one or more element powders of Mo, Si, Y, Cr, Cu, Ce, Ni and Co; S2: The metal mixed slurry is applied on the surface of the metal base mesh by blade coating or roller coating to form a membrane embryo, which is then dried, degreased and sintered to obtain an iron-aluminum-manganese based porous metal membrane.

[0023] The specific preparation method of the above-mentioned Fe-Al-Mn based porous metal film comprises the following steps: S1, metal mixed slurry preparation: The metal mixed slurry is prepared by uniformly mixing Fe powder, Al powder, Mn powder or Fe powder, Al powder, Mn powder and other additive elements, a binder, a dispersant, a defoamer, a leveling agent and pure water with a particle size of 5-100 μm.

[0024] S2, film coating: The metal mixed slurry is applied on the surface of the metal base mesh by scraping or roller coating to form a membrane embryo, and then dried. The drying temperature is set to 60-90° C. and the drying time is set to 1-3 hours.

[0025] S3 debinding and sintering: The support body and the metal film are placed in a sintering furnace for debinding and sintering. The debinding and sintering process is completed in a vacuum or atmosphere sintering furnace at one time. The debinding and sintering system includes the following five stages: the first stage: the sintering temperature is increased from room temperature to 350~450℃, the heating rate is 3~15℃ / min, and the temperature is kept at this temperature for 60~300 minutes; the second stage: the sintering temperature is increased to 550~650℃, the heating rate is 2~15℃ / min, and the temperature is kept at this temperature for 60~300 minutes; The sintering temperature is raised to 850-950°C at a rate of 1-15°C / min and held at this temperature for 60-120 minutes. The sintering temperature is raised to 1000-1100°C at a rate of 1-10°C / min and held at this temperature for 60-420 minutes. The sintering temperature is raised to 1200-1300°C at a rate of 1-5°C / min and held at this temperature for 120-420 minutes. After sintering, the sintering temperature is cooled in the furnace.

[0026] Among them, when the metal mixed slurry is composed of only three elements, Fe, Al, and Mn, the Al element accounts for 8~15% of the total weight of Fe, Al, and Mn, preferably 10~15%, in order to form a continuous and dense Al2O3 oxide film to play an oxidation-resistant role. The Mn element accounts for 3~12% of the total weight of Fe, Al, and Mn, preferably 3~8%, in order to improve the toughness and high-temperature strength of the matrix through solid solution strengthening, and at the same time can preferentially react with the S element in the flue gas to alleviate the corrosion of the S element. The balance is the Fe element.

[0027] Furthermore, the material can be composed of only three elements, Fe, Al, and Mn, or other element powders, such as one or more element powders of Mo, Si, Y, Cr, Cu, Ce, Ni, and Co, can be added within a range not exceeding 10% of the total weight of the metal powder. The purpose is to improve the high-temperature creep resistance of the Fe-Al-Mn-based porous metal film, enhance the passivation ability of the material in SO2-containing flue gas, reduce the tendency to pitting corrosion, and meet the use requirements under high temperature, high dust, and corrosive conditions of the primary flue gas of the converter.

[0028] Preferably, the metal or alloy powder has a particle size of 5 to 100 μm, and most preferably 5 to 30 μm.

[0029] As a preferred solution, the specific dosage of each component in the above metal mixed slurry is: 1) In the present invention, the metal powder accounts for 70 to 90 parts by weight of the total amount of the metal mixed slurry.

[0030] 2) The binder in the present invention includes one or more of polyvinyl alcohol, polyethylene glycol, glycerol, methyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, and sodium carboxymethyl cellulose, accounting for 1 to 10 parts, preferably 1 to 5 parts, of the total amount of the metal mixed slurry.

[0031] 3) The dispersant in the present invention includes one or more of sodium dodecylbenzene sulfonate, sodium stearate, sodium hexametaphosphate, sodium tripolyphosphate, and carboxymethyl cellulose, accounting for 0.05 to 5 parts, preferably 0.05 to 3 parts, of the total amount of the metal mixed slurry.

[0032] 4) The leveling agent in the present invention is one or both of TEGO Glide 410 and TEGO Wet 270 produced by Evonik Specialty Chemicals (Shanghai) Co., Ltd., accounting for 0.05 to 1 part of the total amount of the metal mixed slurry.

[0033] 5) The present invention uses BYK-052 defoamer produced by BYK Chemical Shanghai Co., Ltd., accounting for 0-1 part, preferably 0-0.5 part, of the total amount of the metal mixed slurry.

[0034] 6) Pure water accounts for the remaining weight proportion.

[0035] The present invention also provides an iron-aluminum-manganese (Fe-Al-Mn) based porous metal film prepared by the above-mentioned preparation method, comprising a sintered Fe-Al-Mn based metal powder film layer and a metal base mesh, wherein the sintered Fe-Al-Mn based metal powder film layer is located on the metal base mesh.

[0036] Among them, the sintered Fe-Al-Mn based porous metal membrane is obtained by coating a metal mixed slurry containing Fe, Al, Mn metal powder and dispersant, binder, leveling agent, defoaming agent and pure water on the metal base mesh by roller coating or doctor blade coating, and then drying, degreasing and sintering the obtained membrane blank.

[0037] Among them, the sintered Fe-Al-Mn based porous metal membrane is obtained by coating a metal mixed slurry containing a composition of Fe, Al, Mn metal powders and other added element powders, a dispersant, a binder, a leveling agent, a defoaming agent and pure water on the metal base mesh by roller coating or scraping, and then drying, degreasing and sintering the obtained membrane blank.

[0038] Preferably, the metal base mesh is composed of one or more of 304 stainless steel mesh or perforated mesh, 316L stainless steel mesh or perforated mesh, 310s stainless steel mesh or perforated mesh, 316L stainless steel mesh or perforated mesh, Fe-Al alloy mesh or perforated mesh, FeCrAl alloy mesh or perforated mesh.

[0039] The mesh number of the metal mesh is in the range of 20-100 meshes, and preferably, the mesh number is in the range of 40-60 meshes.

[0040] The short pitch of the metal perforated mesh is 0.5-3.0 mm, and the long pitch of the mesh is 0.5-5.0 mm. Preferably, the short pitch of the mesh is 0.5-2 mm, and the long pitch of the mesh is 0.5-3 mm.

[0041] Preferably, the metal powder film layer is obtained by roller coating or scraping metal slurry on the surface of the metal base mesh, followed by drying, degreasing and sintering.

[0042] Preferably, the metal mixed slurry includes Fe, Al element powder or FeAl alloy powder, Mn element powder, a dispersant, a binder, a leveling agent, a defoaming agent and pure water.

[0043] Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiments are only used to illustrate the present invention and are not used in limiting the scope of the present invention.In addition, should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall equally within the scope limited by the appended claims of the application.

[0044] The following examples were prepared using conventional instruments and equipment in the art. Experimental methods in the following examples, where specific conditions are not specified, were generally performed under conventional conditions or according to the conditions recommended by the manufacturer. The various raw materials used in the following examples, unless otherwise specified, were conventional commercially available products, with specifications conventional in the art. In the present specification and the following examples, unless otherwise specified, "%" indicates percentage by weight, "part" indicates parts by weight, and "ratio" indicates weight ratio.

[0045] The technical solution of this patent is described in detail below in conjunction with specific embodiments, which do not limit this patent.

[0046] Example 1: This embodiment provides a Fe-Al-Mn based porous metal membrane, which is composed of the following components in parts by weight: Fe powder (5μm) 54.25 Al powder (5μm) 15 Mn powder (5μm) 6 Polyvinyl alcohol 2.5 Sodium stearate 1.0 TEGO Wet 2700.05 Deionized water 21.2 Metal base mesh 50 mesh 304 stainless steel mesh The specific preparation process is as follows: S1001: Add polyvinyl alcohol, sodium stearate, and TEGO Wet 270 to deionized water and stir for 1 hour using a magnetic automatic heating stirrer. Add Fe powder, Al powder, and Mn powder to the resulting solution and disperse for 10 minutes using a high-pressure dispersing stirrer at a stirring rate of 1000 rpm. Degas the mixture using a vacuum deaerator to obtain a uniformly dispersed slurry. S1002: Slowly pour the metal slurry prepared in step S1001 onto the surface of the metal base mesh and use a scraper to apply a 400μm metal film layer. The scraping process should be done slowly to prevent the metal slurry from passing through the pores. After the scraping is completed, place the metal base mesh in a vacuum oven at a drying temperature of 70°C for 1 hour. S1003: Place the metal base mesh and metal film dried in S1002 in a vacuum sintering furnace for degreasing and sintering under vacuum atmosphere. The degreasing and sintering process is as follows: heat from room temperature to 450°C at a heating rate of 3°C / min and keep at this temperature for 60 minutes; then heat to 650°C at a heating rate of 2°C / min and keep at this temperature for 60 minutes; then heat to 950°C at a heating rate of 1°C / min and keep at this temperature for 60 minutes; then heat to 1100°C at a heating rate of 1°C / min and keep at this temperature for 60 minutes; then heat to 1300°C at a heating rate of 1°C / min and keep at this temperature for 120 minutes; finally cool in the furnace; Example 2 This embodiment provides a Fe-Al-Mn based porous metal membrane, which is composed of the following components in parts by weight: Fe powder (5μm) 68.5 Al powder (5μm) 13.5 Mn powder (10μm) 8.0 Polyethylene glycol 1.0 Sodium hexametaphosphate 5 TEGO Glide 4100.5 BYK-0520.5 Deionized water 3 Metal base mesh 304 stainless steel mesh punching mesh, short pitch 2.0mm, long pitch 3.0mm The specific preparation process is as follows: S2001: Polyethylene glycol, sodium hexametaphosphate, TEGO Glide 410, and BYK-052 were added to deionized water and stirred for 1 hour using a magnetic automatic heating stirrer. Fe powder, Al powder, and Mn powder were added to the resulting solution and dispersed for 10 minutes using a high-pressure dispersing stirrer at a stirring rate of 1000 rpm. The mixture was then degassed using a vacuum degassing machine to obtain a uniformly dispersed slurry. S2002: Slowly pour the metal slurry prepared in step S2001 onto the surface of the metal base mesh and use a scraper to apply a 400μm metal film layer. The scraping process is carried out slowly to prevent the metal slurry from penetrating the pores. After the scraping is completed, the metal base mesh is placed in a vacuum oven at a drying temperature of 70°C for 1 hour. S2003: The metal base mesh and metal film dried in S2002 are placed in a vacuum sintering furnace for degreasing and sintering under an argon atmosphere. The degreasing and sintering process is as follows: heating from room temperature to 400°C at a heating rate of 10°C / min and keeping at this temperature for 90 minutes; then heating to 600°C at a heating rate of 7°C / min and keeping at this temperature for 90 minutes; then heating to 900°C at a heating rate of 7°C / min and keeping at this temperature for 90 minutes; then heating to 1100°C at a heating rate of 5°C / min and keeping at this temperature for 90 minutes; then heating to 1300°C at a heating rate of 3°C / min and keeping at this temperature for 180 minutes; finally cooling in the furnace.

[0047] Example 3 This embodiment provides a Fe-Al-Mn based porous metal membrane, which is composed of the following components in parts by weight: Fe powder (100 μm) 51.25 Al powder (100 μm) 8.75 Mn powder (100 μm) 5.0 Mo powder (5μm) 10 Polyvinyl alcohol 2.5 Sodium stearate 1.0 TEGO Wet 2700.5 Deionized water 21 Metal base mesh 40 mesh 310s stainless steel mesh The specific preparation process is as follows: S3001: Add polyvinyl alcohol, sodium stearate, and TEGO Wet 270 to deionized water and stir for 1.5 hours using a magnetic automatic heating stirrer. Add Fe powder, Al powder, Mn powder, and Mo powder to the resulting solution and disperse for 10 minutes using a high-pressure dispersing stirrer at a stirring rate of 1000 rpm. Degas the mixture using a vacuum deaerator to obtain a uniformly dispersed slurry. S3002: Slowly pour the metal slurry prepared in step S3001 onto the surface of the metal base mesh and use a roller coater to apply a 200μm metal film layer on both sides. After coating, place the metal base mesh in a vacuum oven at 60°C for 180 minutes. S3003: Place the metal base mesh and metal film dried in S3002 in a vacuum sintering furnace for degreasing and sintering under vacuum atmosphere. The degreasing and sintering process is as follows: heat from room temperature to 450°C at a heating rate of 9°C / min and keep at this temperature for 60 minutes; then heat to 650°C at a heating rate of 7°C / min and keep at this temperature for 60 minutes; then heat to 950°C at a heating rate of 7°C / min and keep at this temperature for 60 minutes; then heat to 1100°C at a heating rate of 5°C / min and keep at this temperature for 60 minutes; then heat to 1300°C at a heating rate of 3°C / min and keep at this temperature for 180 minutes; finally, cool in the furnace.

[0048] Example 4 This embodiment provides a Fe-Al-Mn based porous metal membrane, which is composed of the following components in parts by weight: Fe powder (50μm) 56.25 Al powder (45 μm) 8.75 Mn powder (30μm) 5.0 Ni powder (10 μm) 2.5 Cu powder (10 μm) 2.5 Polyvinyl alcohol 2.5 Sodium stearate 1.0 TEGO Wet 2701.0 Deionized water 23 Metal base mesh 20 mesh 316L stainless steel mesh The specific preparation process is as follows: S4001: Add polyvinyl alcohol, sodium stearate, and TEGO Wet 270 to deionized water and stir for 1.5 hours using a magnetic automatic heating stirrer. Add metal powder to the resulting solution and disperse for 15 minutes using a high-pressure dispersing stirrer at a stirring rate of 1000 rpm. Degas the mixture using a vacuum deaerator to obtain a uniformly dispersed slurry. S4002: Slowly pour the metal slurry prepared in step S4001 onto the surface of the metal base mesh and use a roller coater to apply a 200μm metal film layer on both sides. After coating, place the metal base mesh in a vacuum oven at 80°C for 1 hour. S4003: Place the metal base mesh and metal film dried in S4002 in a vacuum sintering furnace for degreasing and sintering under vacuum atmosphere. The degreasing and sintering process is as follows: heating from room temperature to 500°C at a heating rate of 10°C / min and keeping at this temperature for 90 minutes; then heating to 650°C at a heating rate of 5°C / min and keeping at this temperature for 60 minutes; then heating to 850°C at a heating rate of 15°C / min and keeping at this temperature for 120 minutes; then heating to 1000°C at a heating rate of 10°C / min and keeping at this temperature for 420 minutes; then heating to 1300°C at a heating rate of 3°C / min and keeping at this temperature for 120 minutes; finally cooling in the furnace.

[0049] Example 5 This embodiment provides a Fe-Al-Mn based porous metal membrane, which is composed of the following components in parts by weight: Fe powder (5μm) 59.0 Al powder (5μm) 8.0 Mn powder (30μm) 3.0 Polyvinyl alcohol 10 Sodium tripolyphosphate 0.05 TEGO Wet 2700.5 Deionized water 19.45 Metal base mesh 80 mesh FeCrAl alloy mesh The specific preparation process is as follows: S5001: Add polyvinyl alcohol, sodium tripolyphosphate, and TEGO Wet 270 to deionized water and stir for 1 hour using a magnetic automatic heating stirrer. Add metal powder to the resulting solution and disperse for 10 minutes using a high-pressure dispersing stirrer at a stirring rate of 1000 rpm. Degas the mixture using a vacuum deaerator to obtain a uniformly dispersed slurry. S5002: Slowly pour the metal slurry prepared in step S5001 onto the surface of the metal base mesh and use a scraper to apply a 400μm metal film layer. The scraping process should be done slowly to prevent the metal slurry from penetrating the pores. After the scraping is completed, place the metal base mesh in a vacuum oven at a drying temperature of 70°C for 120 minutes. S5003: Place the metal base mesh and metal film dried in S5002 in a vacuum sintering furnace for degreasing and sintering under vacuum atmosphere. The degreasing and sintering process is as follows: heat from room temperature to 350°C at a heating rate of 15°C / min and keep at this temperature for 120 minutes; then heat to 600°C at a heating rate of 5°C / min and keep at this temperature for 180 minutes; then heat to 950°C at a heating rate of 5°C / min and keep at this temperature for 90 minutes; then heat to 1100°C at a heating rate of 3°C / min and keep at this temperature for 90 minutes; then heat to 1300°C at a heating rate of 3°C / min and keep at this temperature for 270 minutes; finally, cool in the furnace.

[0050] Example 6 This embodiment provides a Fe-Al-Mn based porous metal membrane, which is composed of the following components in parts by weight: FeAl alloy powder (5μm) 70 Mn powder (5μm) 5.0 Polyvinyl alcohol 2.5 Sodium stearate 1.0 TEGO Wet 2700.5 Deionized water 21 Metal base mesh 50 mesh 304 stainless steel mesh The specific preparation process is as follows: S5001: Add polyvinyl alcohol, sodium tripolyphosphate, and TEGO Wet 270 to deionized water and stir for 1 hour using a magnetic automatic heating stirrer. Add metal powder to the resulting solution and disperse for 10 minutes using a high-pressure dispersing stirrer at a stirring rate of 1000 rpm. Degas the mixture using a vacuum deaerator to obtain a uniformly dispersed slurry. S5002: Slowly pour the metal slurry prepared in step S5001 onto the surface of the metal base mesh and use a scraper to apply a 400μm metal film layer. The scraping process should be done slowly to prevent the metal slurry from passing through the pores. After the scraping is completed, place the metal base mesh in a vacuum oven at 90°C for 1 hour. S5003: Place the metal base mesh and metal film dried in S5002 in a vacuum sintering furnace for degreasing and sintering under vacuum atmosphere. The degreasing and sintering process is as follows: heat from room temperature to 350°C at a heating rate of 10°C / min and keep at this temperature for 300 minutes; then heat to 550°C at a heating rate of 5°C / min and keep at this temperature for 300 minutes; then heat to 950°C at a heating rate of 5°C / min and keep at this temperature for 90 minutes; then heat to 1100°C at a heating rate of 3°C / min and keep at this temperature for 90 minutes; then heat to 1300°C at a heating rate of 3°C / min and keep at this temperature for 420 minutes; finally, cool in the furnace.

[0051] Table 1 Examples 1-6 Metal Slurry Components

[0052] Table 2 Examples 1-6 Drying, degreasing and sintering parameters

[0053]

[0054] Comparative Example 1 This comparative example provides a porous metal membrane, which is composed of the following components in parts by weight: 304 stainless steel powder (5μm) 80 Polyvinyl alcohol 1.0 Sodium stearate 0.5 TEGO Wet 2700.5 Deionized water 18 Metal base mesh 50 mesh 304 stainless steel mesh The specific preparation process is as follows: Polyvinyl alcohol, sodium stearate, and TEGO Wet 270 were added to deionized water and stirred for 1 hour using a magnetic automatic heating stirrer. Stainless steel powder was added to the resulting solution and dispersed for 10 minutes using a powerful dispersing stirrer at a stirring rate of 1000 r / min. The mixture was then degassed using a vacuum degassing machine to obtain a uniformly dispersed slurry. Slowly pour the metal slurry prepared in the previous step onto the surface of the metal base mesh and use a scraper to apply a 400μm metal film layer. The scraping process should be done slowly to prevent the metal slurry from penetrating the pores. After the scraping is completed, place the metal base mesh in a vacuum oven at 70°C for 1 hour. The dried stainless steel membrane from the previous step was placed in a vacuum sintering furnace for debinding and sintering under vacuum. The debinding and sintering schedule was as follows: heating from room temperature to 450°C at a rate of 10°C / min, holding at this temperature for 60 minutes; then heating to 950°C at a rate of 7°C / min, holding at this temperature for 120 minutes; and finally cooling in the furnace.

[0055] Comparative Example 2 This comparative example provides a porous metal membrane, which is composed of the following components in parts by weight: Fe powder (5μm) 68 Al powder (5μm) 12 Polyvinyl alcohol 1.0 Sodium stearate 0.5 TEGO Wet 2700.5 Deionized water 18 Metal base mesh 50 mesh 304 stainless steel mesh The specific preparation process is as follows: Add a binder, a dispersant, and a defoamer to deionized water, stir for 1 hour using a magnetic automatic heating stirrer, add stainless steel Fe powder and Al powder to the resulting solution, disperse for 10 minutes using a powerful dispersing stirrer at a stirring rate of 1000 r / min, and then degas using a vacuum deaerator to obtain a uniformly dispersed slurry; Slowly pour the metal slurry prepared in the previous step onto the surface of the metal base mesh and use a scraper to apply a 400μm metal film layer. The scraping process should be done slowly to prevent the metal slurry from penetrating the pores. After the scraping is completed, place the metal base mesh in a vacuum oven at 70°C for 1 hour. The metal film, dried in the previous step, was placed in a vacuum sintering furnace for debinding and sintering under vacuum. The debinding and sintering schedule was as follows: heating from room temperature to 450°C at a rate of 10°C / min, holding at this temperature for 60 minutes; then heating to 950°C at a rate of 7°C / min, holding at this temperature for 120 minutes; and finally cooling in the furnace.

[0056] The performance tests of the samples of Examples 1 to 5 and Comparative Examples 1 and 2 are shown in Table 3. The performance test methods are as follows: 1. Average pore size: measured by the bubble method.

[0057] 2. Filtration flux: The volume of dry air passing through a unit filter area per unit time under unit filtration pressure difference.

[0058] 3. Material tensile strength: According to the Chinese national standard GB / T 7963-1987, the samples were processed into standard tensile specimens and tested using an electronic universal testing machine.

[0059] 4. Material corrosion resistance: Characterized by calculating the mass loss rate after immersion in a 5 mol / L H2SO4 solution (room temperature) for 120 hours (5 days).

[0060] 5. Material resistance to high temperature oxidation: Characterized by calculating the rate of mass increase after maintaining a constant temperature of 1000°C for 90 hours in a static air atmosphere.

[0061] Table 3 Sample performance test table of Example 1-Example 5 and Comparative Example 1-Comparative Example 2

[0062] As shown in Table 3, the Fe-Al-Mn-based porous metal membrane designed by the present invention for converter primary flue gas dust removal significantly outperforms the comparative sample in both tensile strength and acid corrosion resistance, while maintaining comparable key pore properties (such as average pore diameter and porosity). More importantly, the samples optimized by doping with specific alloying elements exhibit even more significant improvements in overall performance.

[0063] In the simulated flue gas (600℃, SO2800mg / m 3 , dust concentration 120g / m 3 ) for 1000 h, with filtration efficiency and pressure drop as evaluation indicators. The results are shown in Table 4.

[0064] Table 4 Comparison table of sample operation effects of Example 1-Example 5 and Comparative Example 1-Comparative Example 2

[0065] As shown in Table 4, the Fe-Al-Mn-based porous metal filter membrane designed by the present invention for converter primary flue gas filtration exhibited minimal fluctuation in filtration efficiency over a 1000-hour operating test, with the filtration pressure drop at the end of the 1000-hour operation remaining at only 750 Pa. In contrast, the comparative filter membrane experienced a significant drop in filtration efficiency, with the filtration pressure drop increasing to over 1800 Pa. This demonstrates that the present invention's filter membrane can effectively maintain high filtration efficiency and low pressure drop characteristics under long-term operating conditions, which is crucial for ensuring the stable and efficient operation of converter flue gas dry-process systems.

[0066] The above content is only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A method for preparing an iron-aluminum-manganese-based porous metal membrane, characterized in that: The following steps are involved: S1: uniformly mixing metal powder, binder, dispersant, defoamer, leveling agent and pure water to form a metal mixed slurry; wherein the metal powder is Fe, Al, Mn series metal powder or a combination of Fe, Al, Mn series metal powder and other added element powders, and the other added element powders are one or more element powders of Mo, Si, Y, Cr, Cu, Ce, Ni and Co; S2: The metal mixed slurry is applied on the surface of the metal base mesh by blade coating or roller coating to form a membrane embryo, which is then dried, degreased and sintered to obtain an iron-aluminum-manganese based porous metal membrane.

2. The method for preparing the iron-aluminum-manganese based porous metal membrane according to claim 1, characterized in that: In parts by weight, the metal mixed slurry includes 70 to 90 parts of metal powder, 1 to 10 parts of a binder, 0.05 to 5 parts of a dispersant, 0 to 1 parts of a defoaming agent, 0.05 to 1 parts of a leveling agent, and the balance is pure water.

3. The method for preparing the iron-aluminum-manganese based porous metal membrane according to claim 1, characterized in that: In parts by weight, the metal mixed slurry includes 70 to 90 parts of metal powder, 1 to 5 parts of a binder, 0.05 to 3 parts of a dispersant, 0 to 0.5 parts of a defoaming agent, 0.05 to 1 parts of a leveling agent, and the balance is pure water.

4. The method for preparing an iron-aluminum-manganese-based porous metal membrane according to claim 1, wherein: The Fe, Al, and Mn metal powders are Fe element powder, Al element powder or FeAl alloy powder, and Mn element powder; the particle size of the Fe, Al, and Mn metal powders and other additive element powders is 5 to 100 μm; when the metal powders are Fe, Al, and Mn metal powders, the Al element accounts for 8 to 15% of the total weight of the Fe element, Al element, and Mn element, the Mn element accounts for 3 to 12% of the total weight of the Fe element, Al element, and Mn element, and the balance is Fe element; when the metal powders are a combination of Fe, Al, and Mn metal powders and other additive element powders, the sum of the weights of the three elements Fe, Al, and Mn in the metal powders accounts for more than 90% of the total weight of the metal powder, and the balance is other additive element powders.

5. The method for preparing the iron-aluminum-manganese based porous metal membrane according to claim 4, characterized in that: The particle size of the Fe, Al, Mn metal powder and other added element powder is 5~30μm; when the metal powder is Fe, Al, Mn metal powder, the Al element accounts for 10~15% of the total weight of the Fe element, Al element and Mn element, the Mn element accounts for 3~8% of the total weight of the Fe element, Al element and Mn element, and the balance is Fe element.

6. The method for preparing an iron-aluminum-manganese based porous metal membrane according to claim 1, wherein: The drying temperature is 60-90°C and the drying time is 1-3 hours. The degreasing and sintering process is completed in a vacuum or atmosphere sintering furnace at one time. The specific steps are as follows: the sintering temperature is increased from room temperature to 350-450°C at a heating rate of 3-15°C / min and kept at this temperature for 60-300 minutes. Raise the sintering temperature to 550-650°C at a rate of 2-15°C min-1 and hold at this temperature for 60-300 minutes. Raise the sintering temperature to 850-950°C at a rate of 1-15°C / min and hold at this temperature for 60-120 minutes. Raise the sintering temperature to 1000°C~1100°C at a rate of 1~10°C / min and keep at this temperature for 60~420 minutes; The sintering temperature is raised to 1200°C~1300°C at a heating rate of 1~5°C / min, and maintained at this temperature for 120~420 minutes. After sintering, the furnace is cooled.

7. The method for preparing an iron-aluminum-manganese based porous metal membrane according to claim 1, wherein: The binder includes one or more of polyvinyl alcohol, polyethylene glycol, glycerol, methyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, and sodium carboxymethyl cellulose; the dispersant is one or more of sodium dodecylbenzene sulfonate, sodium stearate, sodium hexametaphosphate, sodium tripolyphosphate, and carboxymethyl cellulose; the leveling agent is one or both of TEGO Glide 410 and TEGO Wet 270; and the defoamer is BYK-052.

8. An iron-aluminum-manganese-based porous metal membrane prepared according to the method for preparing an iron-aluminum-manganese-based porous metal membrane according to any one of claims 1 to 7, characterized in that: The invention comprises a sintered Fe-Al-Mn based metal powder film layer and a metal base mesh; wherein the sintered Fe-Al-Mn based metal powder film layer is located on the metal base mesh.

9. The iron-aluminum-manganese based porous metal membrane according to claim 1, characterized in that: The mesh type of the metal base mesh is a stainless steel mesh or a punched mesh; the material of the metal base mesh is selected from one or more of 304 stainless steel, 316L stainless steel, 310s stainless steel, Fe-Al alloy, and FeCrAl alloy; the mesh number range of the metal base mesh is 20 to 100 meshes; when the mesh type of the metal base mesh is a punched mesh, the short pitch of the mesh is 0.5 to 3.0 mm, and the long pitch of the mesh is 0.5 to 5.0 mm.

10. Use of the iron-aluminum-manganese based porous metal membrane prepared by the preparation method of the iron-aluminum-manganese based porous metal membrane according to any one of claims 1 to 7 as a filter material in converter primary flue gas filtration.

Images