Porous carbon material for filtering high-temperature flue gas as well as preparation method and application of porous carbon material

Abstract

The invention provides a porous carbon material for high-temperature flue gas filtration, and a preparation method and application thereof, and the preparation method comprises the following steps: mixing carbon powder, a metal oxide and an adhesive to obtain prefabricated carbon particles; sintering the prefabricated carbon granules in a reducing atmosphere to obtain sintered carbon granules; roasting the sintered carbon granules in a chlorine atmosphere to obtain roasted carbon granules and roasted flue gas; the roasted carbon particles are subjected to acid pickling and then dried, and the porous carbon material for high-temperature flue gas filtration is obtained. The mixing mass ratio of the carbon powder to the metal oxide to the adhesive is 1: (0.25 to 0.5): (0.15 to 0.3). The preparation method is simple in steps and convenient to operate. And the prepared porous carbon material has a relatively high specific surface area, and meets the high-performance requirements of the fields of industrial production and the like on a high-temperature flue gas filtering material.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of porous carbon material preparation, and particularly relates to a porous carbon material for high-temperature flue gas filtration, a preparation method and application. BACKGROUND

[0002] Porous carbon materials have a wide range of applications in various fields due to their unique physical and chemical properties. Their high specific surface area provides a large number of adsorption sites, effectively adsorbing and filtering various substances. In the field of environmental purification, porous carbon materials can be used to remove harmful gases and particulate matter from the air, and their performance is crucial, especially in high-temperature flue gas filtration.

[0003] However, the existing methods for preparing porous carbon materials have some drawbacks and deficiencies. Traditional preparation methods usually include template methods and activation methods. Template methods require the use of specific template materials to construct porous structures, but this method often has problems such as difficulty in removing templates, high cost, and difficulty in accurately controlling pore structure. Although the activation method can prepare porous carbon materials, it may cause damage to the structure of the material during the activation process, affecting its mechanical strength and stability. In addition, some preparation methods also have problems such as harsh reaction conditions, high energy consumption, and environmental pollution, which limit their large-scale industrial application. Based on this, the present application proposes a porous carbon material for high-temperature flue gas filtration, a preparation method and application. SUMMARY

[0004] The main purpose of the present application is to provide a porous carbon material for high-temperature flue gas filtration, a preparation method and application, which aims to solve the technical problems of complex preparation method and high cost of porous carbon materials in the prior art.

[0005] To achieve the above-mentioned purpose, the present application provides a preparation method of a porous carbon material for high-temperature flue gas filtration, comprising the following steps: Mixing carbon powder, metal oxide and adhesive to obtain preformed carbon particles.

[0006] Sintering the preformed carbon particles under a reducing atmosphere to obtain sintered carbon particles.

[0007] Roasting the sintered carbon particles under a chlorine atmosphere to obtain roasted carbon particles and roasting flue gas.

[0008] Acid pickling and drying the roasted carbon particles to obtain the porous carbon material for high-temperature flue gas filtration.

[0009] The mass ratio of the carbon powder, the metal oxide and the adhesive is 1:(0.25-0.5):(0.15-0.3).

[0010] According to the embodiment of the present application, the metal oxide comprises FeO, Fe2O3 and NiO.

[0011] The mass ratio of FeO, Fe2O3 and NiO is 1:(0.5~1):(0.1~0.2).

[0012] According to the embodiment of the present application, the adhesive comprises one or more of phenolic resin, polyimide.

[0013] According to the embodiment of the present application, the reducing atmosphere comprises a hydrogen atmosphere.

[0014] According to the embodiment of the present application, the sintering temperature is 900~1200℃, and the sintering time is 60~120min.

[0015] According to the embodiment of the present application, the amount of chlorine is 5~10 times of the total molar amount of metal atoms contained in the sintered carbon particles.

[0016] The calcination temperature is 600~900℃, and the calcination time is 60~120min.

[0017] According to the embodiment of the present application, further comprising: mixing the calcination flue gas with an oxidizing gas, and reacting at 800~1000℃ for 10~30min, so as to convert the metal chlorides in the flue gas into metal oxides.

[0018] The oxidizing gas comprises one or more of air, oxygen, ozone.

[0019] The amount of the oxidizing gas added is 10~15 times of the molar amount of chlorine.

[0020] According to the embodiment of the present application, the acid used for pickling is one or more of hydrochloric acid, nitric acid.

[0021] The molar concentration of the acid used for pickling is 0.5~1mol / L, and the pickling time is 30~60min.

[0022] The present application also provides a porous carbon material for high-temperature flue gas filtration, which is prepared by the preparation method as described above.

[0023] The present application also provides the application of the porous carbon material for high-temperature flue gas filtration as described above in high-temperature flue gas filtration.

[0024] Compared with the prior art, the present application has the following beneficial effects: The porous carbon material for high-temperature flue gas filtration, the preparation method and the application described above, by mixing carbon powder, metal oxide and binder according to a specific mass ratio, the preformed carbon particles are obtained. The addition of the binder enables the carbon powder and the metal oxide to be closely combined, thereby providing a stable structural basis for subsequent sintering and other processes, and preventing the powder from loosening and falling off during processing.

[0025] Sintering in a reducing atmosphere enables the metal oxide in the preformed carbon particles to be reduced to elemental metal or low-valence metal compounds. These metals will react with chlorine gas to form corresponding chlorides during the subsequent chlorine roasting process, thereby achieving the purpose of removing the metal. Meanwhile, the reduction process of the metal also forms some micropores or defect structures in the carbon skeleton.

[0026] Roasting the sintered carbon particles in a chlorine atmosphere enables the formation and volatilization of metal chlorides to leave pores in the carbon skeleton, thereby forming a porous structure. By controlling the amount of chlorine gas, the roasting temperature and time and other parameters, the pore structure can be controlled, so that the prepared porous carbon material has the pore structure characteristics required for high-temperature flue gas filtration. In addition, this step also effectively removes metal impurities from the carbon particles, avoiding the adverse effects of metal impurities on the high-temperature flue gas filtration effect during subsequent use, and also helps to improve the purity and chemical stability of the material.

[0027] Finally, by dissolving and removing the metal chlorides and other impurities remaining in the roasted carbon particles through acid pickling, the purity is further improved, the interference of impurities on the high-temperature flue gas filtration performance is reduced, and the porous carbon material has good filtration effect and stability.

[0028] The preparation steps of the present application are simple and convenient to operate. Through the synergistic effect of the above-mentioned multiple steps, the prepared porous carbon material has a high specific surface area, thereby achieving good filtration effect on high-temperature flue gas and meeting the high-performance requirements of high-temperature flue gas filtration materials in industrial production and other fields. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained according to the structures shown in these drawings without creative labor for those skilled in the art.

[0030] Figure 1 Flow chart of the preparation method of the porous carbon material for high-temperature flue gas filtration of the present application; Figure 2 Electron microscope image of the porous carbon material for high-temperature flue gas filtration prepared in Example 1 of the present application.

[0031] The objectives, functional characteristics and advantages of the present application will be further described with reference to the embodiments in combination with the accompanying drawings. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present application will be apparently and completely described with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0033] Moreover, the technical solutions among the embodiments of the present application can be combined with each other, but it must be based on that a person of ordinary skill in the art can realize. When the combination of the technical solutions appears to be contradictory or unachievable, it should be considered that the combination of the technical solutions does not exist and is not within the protection scope required by the present application.

[0034] To achieve the above-mentioned object, the present application provides a preparation method of two-dimensional layered kaolinite nanofiltration membrane, comprising the following steps: S1: mixing carbon powder, metal oxide and adhesive to obtain preformed carbon particles.

[0035] The mass ratio of the carbon powder, the metal oxide and the adhesive is 1:(0.25-0.5):(0.15-0.3).

[0036] By mixing the carbon powder, the metal oxide and the adhesive uniformly according to a certain mass ratio, the adhesive can tightly bond the carbon powder and the metal oxide particles together to prevent the carbon powder and the metal oxide particles from falling off, so as to facilitate the subsequent use in high-temperature flue gas filtration. The metal oxide usually has a high melting point and thermal stability, which can improve the thermal stability of the preformed carbon particles. When the preformed carbon particles are used in a high-temperature environment, the metal oxide can play a certain supporting and protective role to prevent the carbon powder from being excessively oxidized or the structure from collapsing at high temperature.

[0037] In some embodiments, the mass ratio of the carbon powder, the metal oxide and the adhesive is 1:(0.25-0.3):(0.15-0.2).

[0038] In some embodiments, the mass ratio of the carbon powder, the metal oxide and the adhesive is 1:(0.4-0.5):(0.2-0.3).

[0039] In some embodiments, the diameter and shape of the preformed carbon particles are not specifically limited. For example, if the preformed carbon particles are spherical, the diameter of the preformed carbon particles is 0.1-1.0 cm.

[0040] S2: sintering the preformed carbon particles under a reducing atmosphere to obtain sintered carbon particles.

[0041] In some embodiments, the reducing atmosphere comprises a hydrogen atmosphere. Under the reducing atmosphere, the metal oxides in the preformed carbon particles are reduced to metal elements or metal carbides. Such a composite structure can improve the thermal stability and chemical stability of the material, allowing it to maintain good performance in high-temperature or corrosive environments. At the same time, the sintering process can cause the particles in the preformed carbon particles to sinter and densify, improving the mechanical strength of the material and making it more durable and able to withstand greater mechanical stress during use.

[0042] S3: calcining the sintered carbon particles in a chlorine atmosphere to obtain calcined carbon particles and calcination flue gas.

[0043] In some embodiments, the amount of chlorine is 5-10 times the total molar amount of metal atoms contained in the sintered carbon particles.

[0044] In some embodiments, by controlling the amount of chlorine and the calcination conditions, the metal elements or metal oxides in the sintered carbon particles are fully chlorinated by the chlorine atmosphere, generating corresponding metal chlorides. These metal chlorides are usually volatile and will escape in gaseous form during the calcination process, thereby removing the metal and improving the purity of the calcined carbon particles. Moreover, the escape of metal chlorides creates pores in the interior of the calcined carbon particles. These pores can increase the specific surface area of the carbon material, and the porous structure can provide more active sites, thereby improving its adsorption performance and reactivity. In addition, the calcination flue gas produced during the calcination process is metal chloride, which can be recycled and reused through an effective collection and treatment system.

[0045] S4: drying the calcined carbon particles after pickling to obtain the porous carbon material for high-temperature flue gas filtration.

[0046] In some embodiments, pickling can remove residual metal chlorides and other impurities in the calcined carbon particles, further improving the purity of the porous carbon material for high-temperature flue gas filtration.

[0047] The above method for preparing a porous carbon material for high-temperature flue gas filtration involves mixing carbon powder, metal oxides, and a binder in a specific mass ratio to obtain preformed carbon particles. The addition of the binder allows the carbon powder and metal oxides to be tightly bonded, providing a stable structural foundation for subsequent sintering and other processes, preventing the powder from loosening and falling off during processing.

[0048] Sintering under a reducing atmosphere can reduce the metal oxides in the pre-prepared carbon particles into elemental metals or low-valence metal compounds, and these metals can react with chlorine to form corresponding chlorides in the subsequent chlorine roasting process, thereby achieving the purpose of removing metals, and the reduction process of the metals also forms some micropores or defect structures in the carbon skeleton.

[0049] Roasting the sintered carbon particles in a chlorine atmosphere can leave pores in the carbon skeleton due to the generation and volatilization of metal chlorides, thereby forming a porous structure. By controlling the amount of chlorine, roasting temperature and time, etc., the pore structure can be controlled, so that the prepared porous carbon material has the pore structure characteristics required for high-temperature flue gas filtration. In addition, this step also effectively removes metal impurities from the carbon particles, avoiding the adverse effects of metal impurities on high-temperature flue gas filtration in subsequent use, and also helps to improve the purity and chemical stability of the material.

[0050] Finally, by dissolving and removing the residual metal chlorides and other impurities in the roasted carbon particles through acid washing, the purity is further improved, the interference of impurities on high-temperature flue gas filtration performance is reduced, and the porous carbon material has good filtration effect and stability.

[0051] Moreover, the preparation steps of the present application are simple, easy to operate, and suitable for large-scale industrial production.

[0052] In some embodiments, the metal oxides include FeO, Fe2O3 and NiO.

[0053] The mass ratio of FeO, Fe2O3 and NiO is 1:(0.5-1.0):(0.1-0.2).

[0054] During sintering under a reducing atmosphere, FeO and Fe2O3 are reduced to elemental metals or low-valence metal compounds, and these metals can react with chlorine to form corresponding chlorides in the subsequent chlorine roasting process, thereby achieving the purpose of removing metals, and the reduction process of the metals also forms some micropores or defect structures in the carbon skeleton. Roasting the sintered carbon particles in a chlorine atmosphere can leave pores in the carbon skeleton due to the generation and volatilization of metal chlorides, thereby forming a certain pore structure. NiO has high thermal stability, and its addition helps to stabilize the structure of the sintered carbon particles, so that they do not collapse during sintering.

[0055] In some embodiments, the mass ratio of FeO, Fe2O3 and NiO is 1:(0.6-1.0):(0.1-0.2).

[0056] In some embodiments, the mass ratio of FeO, Fe2O3 and NiO is 1:(0.5-0.8):(0.1-0.15).

[0057] In some embodiments, the binder comprises one or more of phenolic resin, polyimide.

[0058] In some embodiments, the binder comprises phenolic resin, and the purity of the phenolic resin is analytical pure. The phenolic resin has good mechanical properties and thermal stability. In the preformed carbon particles, the phenolic resin can tightly bond the carbon powder and metal oxide particles together to form a solid structure. During sintering and calcination, the phenolic resin can be further carbonized to form a carbonaceous bonding phase, enhancing the overall mechanical strength of the material.

[0059] In some embodiments, the sintering temperature is 900-1200°C, and the sintering time is 60-120 min.

[0060] In some embodiments, the sintering temperature is 950-1050°C, and the sintering time is 60-90 min.

[0061] In some embodiments, the calcination temperature is 600-900°C, and the calcination time is 60-120 min.

[0062] In some embodiments, the calcination temperature is 800-900°C, and the calcination time is 60-70 min.

[0063] In some embodiments, further comprising: mixing the calcination flue gas with an oxidizing gas, and reacting at 800-1000°C for 10-30 min to convert the metal chlorides in the flue gas into metal oxides.

[0064] In some embodiments, the oxidizing gas comprises one or more of air, oxygen, ozone.

[0065] The amount of oxidizing gas added is 10-15 times the molar amount of chlorine gas.

[0066] In some embodiments, the oxidizing gas is oxygen. The metal chlorides (such as FeCl3, NiCl2, etc.) in the calcination flue gas react with the oxidizing gas to convert into metal oxides (such as Fe2O3, NiO, etc.), which can continue to be used as raw materials in the preparation of porous carbon materials, realizing the recycling of resources. The chlorine gas generated during the reaction can be recovered by condensation and other methods for subsequent production processes, further reducing the emission of chlorine gas.

[0067] In some embodiments, the calcination flue gas is mixed with an oxidizing gas and reacted at 900-1000°C for 15-25 min to convert the metal chlorides in the flue gas into metal oxides.

[0068] In some embodiments, the acid used for pickling comprises one or more of hydrochloric acid, nitric acid.

[0069] The molar concentration of the acid used in the acid washing is 0.5-1 mol / L, and the acid washing time is 30-60 min.

[0070] In some embodiments, the acid used in the acid washing is hydrochloric acid or nitric acid.

[0071] The molar concentration of the acid used in the acid washing is 0.5-0.8 mol / L, and the acid washing time is 30-45 min. Both hydrochloric acid and nitric acid are strong acids, which can effectively dissolve metal chlorides and other residual metal impurities, and significantly improve the purity of the porous carbon material. At the same time, during the acid washing process, the acid can enter the pores of the porous carbon material, dissolve the impurities in the pores, and make the pores more unobstructed. The specific surface area of the porous carbon material can be increased, and the adsorption performance can be improved.

[0072] The application also provides a porous carbon material for high-temperature flue gas filtration, which is prepared by the above preparation method.

[0073] The application also provides the application of the above porous carbon material for high-temperature flue gas filtration in high-temperature flue gas filtration.

[0074] In some embodiments, the above porous carbon material for high-temperature flue gas filtration is applied in separating arsenic trioxide in the flue gas generated in the roasting process of arsenic-containing refractory gold ore. The arsenic-containing refractory gold ore is placed in a tube furnace and roasted at 630 DEG C. The prepared porous carbon material for high-temperature flue gas filtration is filled into one end of the outlet of the tube furnace, and the temperature at this end is 400 DEG C. After the flue gas generated in the roasting process of the arsenic-containing refractory gold ore is filtered, the retention rate of arsenic is 99.4% or above.

[0075] In some embodiments, the above porous carbon material for high-temperature flue gas filtration is applied in separating ferric chloride and nickel chloride. The ferric chloride and nickel chloride are placed in a tube furnace and roasted at 1000 DEG C, and the ferric chloride and nickel chloride are volatilized. The prepared porous carbon material for high-temperature flue gas filtration is filled into one end of the outlet of the tube furnace, and the temperature at this end is 500 DEG C. After the flue gas is filtered, the retention rate of nickel chloride is 99.7-99.9%, and the purity of the ferric chloride obtained after filtration is 99.9%.

[0076] The above porous carbon material for high-temperature flue gas filtration has a high specific surface area, thereby realizing good filtering effect on high-temperature flue gas, and having good application effect in separating arsenic trioxide in the flue gas generated in the roasting process of arsenic-containing refractory gold ore and in separating ferric chloride and nickel chloride. The application meets the high-performance requirements of high-temperature flue gas filtration materials in the field of industrial production and the like.

[0077] In order to further understand the application, examples are given as follows: Example 1 A method for preparing a porous carbon material for high-temperature flue gas filtration, comprising the following steps: S1: mixing carbon powder, metal oxide and binder to obtain preformed carbon particles. The carbon powder is a commercially available carbon powder with a carbon content of 99.2%, the metal oxide is FeO, Fe2O3 and NiO, and the binder is phenolic resin. The mass ratio of the carbon powder, metal oxide and binder is 1:0.5:0.3, and the mass ratio of FeO, Fe2O3 and NiO is 1:0.5:0.1.

[0078] S2: sintering the preformed carbon particles under a hydrogen atmosphere to obtain sintered carbon particles. The sintering temperature is 1000°C, and the sintering time is 80 min.

[0079] S3: calcining the sintered carbon particles under a chlorine atmosphere to obtain calcined carbon particles and calcined flue gas. The calcination temperature is 900°C, and the calcination time is 60 min. The amount of chlorine added is 5 times the total molar amount of metal atoms contained in the sintered carbon particles. The treatment method of the calcined flue gas is as follows: introducing the calcined flue gas into an oxidative transformation reaction furnace with an oxidizing gas of oxygen, reacting at 1000°C for 20 min, and the amount of the oxidizing gas added is 10 times the molar amount of chlorine. The oxidation conversion rates of iron chloride and nickel chloride in the calcined flue gas are 97.4% and 99.3%, respectively.

[0080] S4: acid washing the calcined carbon particles in a 0.5 mol / L nitric acid solution for 45 min, and then drying in a vacuum drying oven at 70°C for 6 h to obtain a porous carbon material for high-temperature flue gas filtration.

[0081] The specific surface area of the porous carbon material for high-temperature flue gas filtration prepared by the adsorption method is 3291 m 2 / g.

[0082] The porous carbon material for high-temperature flue gas filtration prepared in Example 1 is used to separate arsenic trioxide in the flue gas generated in the roasting process of arsenic-containing refractory gold ore. The mass of gold in each ton of arsenic-containing refractory gold ore is 60.25 g. The main chemical components of the arsenic-containing refractory gold ore are shown in Table 1.

[0083] Table 1: Main chemical components of arsenic-containing refractory gold ore (wt %) 10 g of arsenic-containing refractory gold ore is placed in a tube furnace and roasted at 630°C. The porous carbon material for high-temperature flue gas filtration prepared is filled into the end of the tube furnace outlet, where the temperature is 400°C. After filtering the flue gas generated in the roasting process of the arsenic-containing refractory gold ore, the arsenic retention rate is 99.4%.

[0084] The porous carbon material for high-temperature flue gas filtration prepared in Example 1 was used to separate ferric chloride and nickel chloride. 7 g of ferric chloride and 3 g of nickel chloride were placed in a tube furnace and calcined at 1000°C, and the ferric chloride and nickel chloride were volatilized. The prepared porous carbon material for high-temperature flue gas filtration was filled into the outlet end of the tube furnace, where the temperature was 500°C. After the flue gas was filtered, the retention rate of nickel chloride was 99.9%, and the purity of the ferric chloride obtained after filtration was 99.9%.

[0085] Example 2 A method for preparing a porous carbon material for high-temperature flue gas filtration, comprising the following steps: S1: mixing carbon powder, metal oxides and a binder to obtain preformed carbon particles. The carbon powder is a commercially available carbon powder with a carbon content of 99.2%, the metal oxides are FeO, Fe2O3 and NiO, and the binder is phenolic resin. The mass ratio of the carbon powder, metal oxides and binder is 1:0.25:0.15, and the mass ratio of FeO, Fe2O3 and NiO is 1:1:0.2.

[0086] S2: sintering the preformed carbon particles under a hydrogen atmosphere to obtain sintered carbon particles. The sintering temperature is 950°C, and the sintering time is 100 min.

[0087] S3: calcining the sintered carbon particles under a chlorine atmosphere to obtain calcined carbon particles and calcined flue gas. The calcination temperature is 800°C, and the calcination time is 100 min. The amount of chlorine added is 8 times the total molar amount of metal atoms contained in the sintered carbon particles.

[0088] S4: acid washing the calcined carbon particles in a 0.5 mol / L nitric acid solution for 45 min, and then drying them in a vacuum drying oven at 70°C for 6 h to obtain a porous carbon material for high-temperature flue gas filtration.

[0089] The specific surface area of the prepared porous carbon material for high-temperature flue gas filtration was tested by the adsorption method, and the specific surface area was 2372 m 2 / g.

[0090] The porous carbon material for high-temperature flue gas filtration prepared in Example 2 was used to separate ferric chloride and nickel chloride. 7 g of ferric chloride and 3 g of nickel chloride were placed in a tube furnace and calcined at 1000°C, and the ferric chloride and nickel chloride were volatilized. The prepared porous carbon material for high-temperature flue gas filtration was filled into the outlet end of the tube furnace, where the temperature was 500°C. After the flue gas was filtered, the retention rate of nickel chloride was 99.7%, and the purity of the ferric chloride obtained after filtration was 99.9%.

[0091] Comparative Example 1 Compared with Example 1, the composition of the metal oxides was changed.

[0092] The metal oxide is FeO, Fe2O3, and the mass ratio of FeO and Fe2O3 is 1:0.5. The other steps are the same as those in Example 1, and a porous carbon material for high-temperature flue gas filtration is obtained.

[0093] The specific surface area of the prepared porous carbon material for high-temperature flue gas filtration is 1641 m 2 / g.

[0094] Comparative Example 2 Compared with Example 1, the mass ratio of the metal oxide is changed.

[0095] The mass ratio of the metal oxides FeO, Fe2O3 and NiO is 1:0.1:0.3. The other steps are the same as those in Example 1, and a porous carbon material for high-temperature flue gas filtration is obtained.

[0096] The specific surface area of the prepared porous carbon material for high-temperature flue gas filtration is 1930 m 2 / g.

[0097] The mass ratio of the metal oxides FeO, Fe2O3 and NiO is 1:0.1:0.3. The other steps are the same as those in Example 1, and a porous carbon material for high-temperature flue gas filtration is obtained. Figure 1 is a flow chart of the preparation method of the porous carbon material for high-temperature flue gas filtration according to the present application; Figure 2 is a scanning electron microscope image of the porous carbon material for high-temperature flue gas filtration prepared in Example 1 of the present application. Figure 2 As can be seen from the image, the prepared porous carbon material for high-temperature flue gas filtration has a dense porous structure, significantly increasing the specific surface area of the material, providing more adsorption sites for harmful substances in the flue gas, thereby improving the adsorption capacity of the material for harmful substances, achieving efficient filtration of the flue gas, and maintaining stability during high-temperature flue gas filtration, preventing clogging or structural collapse, and ensuring the performance stability of the material during long-term use.

[0098] As can be seen from Example 1, by adjusting the composition and mass ratio of the carbon powder, metal oxide and binder, the carbon powder and metal oxide can be tightly combined, providing a stable structural basis for subsequent sintering and other processes, preventing the powder from loosening and falling off during processing. Sintering in a reducing atmosphere can reduce the metal oxide in the preformed carbon particles to elemental metal or low-valence metal compounds, thereby achieving the purpose of removing metal, and at the same time, the reduction process of the metal also forms some micropores or defect structures in the carbon skeleton. A porous structure is obtained. The sintered carbon particles are calcined in a chlorine atmosphere, and the formation and volatilization of metal chlorides further form a porous structure. By dissolving and removing the residual metal chlorides and other impurities in the calcined carbon particles through acid pickling, the purity is further improved, the interference of impurities on the high-temperature flue gas filtration performance is reduced, and the porous carbon material has good filtration effect and stability. The specific surface area of the prepared porous carbon material for high-temperature flue gas filtration is 3291 m 2 / g, and has excellent filtering effect in high-temperature flue gas filtration.

[0099] Moreover, the preparation steps of the present application are simple and convenient to operate. Through the synergistic effect of the above multiple steps, the prepared porous carbon material has a high specific surface area, thereby achieving good filtering effect on high-temperature flue gas, and meeting the high-performance requirements of high-temperature flue gas filtering materials in industrial production and other fields.

[0100] To sum up, in the above technical solution of the present application, the above is only the preferred embodiment of the present application, and does not limit the patent scope of the present application, and any equivalent structural transformation made under the technical concept of the present application, or direct / indirect application in other related technical fields is included in the patent protection scope of the present application.

Claims

1. A method for preparing porous carbon materials for high-temperature flue gas filtration, characterized in that, Includes the following steps: S1: After mixing carbon powder, metal oxide and binder, pre-formed carbon particles are obtained; S2: The pre-made carbon particles are sintered in a reducing atmosphere to obtain sintered carbon particles; S3: The sintered carbon particles are roasted in a chlorine atmosphere to obtain roasted carbon particles and roasting flue gas; S4: The calcined carbon particles are acid-washed and then dried to obtain the porous carbon material used for high-temperature flue gas filtration. The mass ratio of the carbon powder, the metal oxide, and the binder is 1:(0.25~0.5):(0.15~0.3).

2. The method for preparing porous carbon material for high-temperature flue gas filtration according to claim 1, characterized in that, The metal oxides include FeO, Fe2O3, and NiO; The mass ratio of FeO, Fe2O3 and NiO is 1:(0.5~1):(0.1~0.2).

3. The method for preparing porous carbon materials for high-temperature flue gas filtration according to claim 1, characterized in that, The adhesive includes one or more of phenolic resin and polyimide.

4. The method for preparing porous carbon material for high-temperature flue gas filtration according to claim 1, characterized in that, The reducing atmosphere includes a hydrogen atmosphere.

5. The method for preparing porous carbon material for high-temperature flue gas filtration according to claim 1, characterized in that, The sintering temperature is 900~1200℃, and the sintering time is 60~120min.

6. The method for preparing porous carbon material for high-temperature flue gas filtration according to claim 1, characterized in that, The amount of chlorine gas is 5 to 10 times the total molar amount of metal atoms contained in the sintered carbon particles; The roasting temperature is 600~900℃, and the roasting time is 60~120min.

7. The method for preparing porous carbon material for high-temperature flue gas filtration according to claim 1, characterized in that, Also includes: The roasting flue gas is mixed with an oxidizing gas and reacted at 800~1000℃ for 10~30 min to convert the metal chlorides in the flue gas into metal oxides. The oxidizing gas includes one or more of air, oxygen, and ozone; The amount of oxidizing gas added is 10 to 15 times the molar amount of chlorine.

8. The method for preparing porous carbon material for high-temperature flue gas filtration according to claim 1, characterized in that, The acid used for pickling is one or more of hydrochloric acid and nitric acid; The acid used for pickling has a molar concentration of 0.5~1 mol / L, and the pickling time is 30~60 min.

9. A porous carbon material for high-temperature flue gas filtration, characterized in that, It is prepared by the preparation method described in any one of claims 1 to 8.

10. The application of the porous carbon material for high-temperature flue gas filtration as described in claim 9 in high-temperature flue gas filtration.

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