Method for preparing conductive porous ceramic from solid waste material and conductive porous ceramic

Abstract

The invention discloses a method for preparing conductive porous ceramic from a solid waste material and the conductive porous ceramic, and belongs to the technical field of solid waste utilization. The preparation method comprises the following steps: mixing desulfurized dust, waste glass, waste graphite and a cosolvent to obtain mixed powder; carrying out compression molding on the mixed powder to obtain a mixed block; the mixed block is calcined to obtain the porous conductive ceramic, and the prepared porous conductive ceramic has conductivity and permeability and can be applied to the high-end application field with certain requirements for conductivity, porous structure and strength. And the preparation method has the advantages of green and environment-friendly raw materials, simplicity in operation, low cost, easiness in large-scale production and the like, has a relatively good practical application prospect, and realizes cooperative treatment and resource utilization of various solid waste resources.

Description

Technical Field

[0001] The present invention relates to the technical field of solid waste utilization, and in particular to a method for preparing conductive porous ceramics using solid waste materials and the conductive porous ceramics. Background Art

[0002] The fuel and raw materials used in float glass production contain sulfur, which causes a large amount of SO in the flue gas discharged from the kiln. 2 . In order to carry out flue gas desulfurization, soda lime is used for desulfurization operation, which will produce a large amount of powdered solid waste. The main components of these desulfurization dust are calcium sulfate, calcium carbonate, calcium hydroxide, etc. The efficient recovery and resource treatment technology of these desulfurization dust is particularly important for the economic and environmental benefits of enterprises. At present, most of the research on desulfurization dust in the float glass industry is to reduce the sulfur content in the fuel and raw materials used in production, and has not effectively solved the problem of resource utilization of desulfurization solid waste.

[0003] At the same time, glass is widely used in our daily life and all walks of life. Not only glass manufacturers will produce a large amount of waste glass, but the amount of waste glass produced in life is also increasing. According to the United Nations, 7% of the world's solid waste is waste glass. my country produces 10.4 million tons of waste glass every year, accounting for 5% of the total solid waste. At present, only 13%-15% of waste glass in my country is recycled, and more is landfilled as garbage, which also causes ecological pollution and waste of resources and energy.

[0004] On the other hand, graphite is widely used in negative electrode materials of lithium-ion batteries due to its advantages such as good conductivity, high reversible capacity and good cycle stability. As the most commonly used negative electrode material, graphite accounts for 12% to 21% of the total battery weight and is widely used in commercial lithium batteries, especially in the field of power batteries. The booming lithium battery industry has brought a huge number of scrapped batteries, and it is estimated that a total of 11 million tons of scrapped lithium batteries will be generated by 2030. At present, the recycling technology of retired power batteries focuses on the recycling of positive electrode materials, but the disassembled waste graphite is difficult to achieve efficient utilization due to the lack of effective technical means. Most companies are still at the stage of inefficient incineration as fuel or landfill treatment.

[0005] Therefore, how to efficiently and comprehensively utilize the above solid waste resources, develop functional high-value products based on the synergistic advantages of multiple solid waste resources in light of the characteristics of each type of solid waste resources, is of great strategic significance for simultaneously solving the problems of multiple solid waste resource treatment. Summary of the invention

[0006] The main purpose of the present invention is to provide a method for preparing conductive porous ceramics from solid waste materials and conductive porous ceramics, so as to solve the technical problem that it is difficult to achieve coordinated utilization of multiple solid waste materials.

[0007] To achieve the above object, the present invention provides a method for preparing conductive porous ceramics from solid waste materials, characterized in that it comprises the following steps:

[0008] Mixing desulfurization dust, waste glass, waste graphite and a solvent to obtain a mixed powder;

[0009] Pressing the mixed powder into a mixed block;

[0010] The mixed block is calcined to obtain a porous conductive ceramic.

[0011] In some embodiments of the present invention, the desulfurization dust includes at least one of calcium sulfate, calcium carbonate, and calcium hydroxide;

[0012] And / or, the waste graphite includes graphite recovered from waste batteries.

[0013] In some embodiments of the present invention, the particle size of the desulfurization dust, waste glass, and waste graphite ranges from 50 μm to 300 μm.

[0014] In some embodiments of the present invention, the mass ratio of the desulfurization dust and the waste glass is (1:9) to (6:4);

[0015] And / or, the mass ratio of the total mass of the desulfurization dust and waste glass to the waste graphite is 100:(0.1-20);

[0016] And / or, the solid-to-liquid ratio of the total mass of the desulfurization dust, waste glass, waste graphite and the co-solvent is (5:1) to (1:1) (g / mL).

[0017] In some embodiments of the present invention, the co-solvent includes at least one of boric acid and borax solution.

[0018] In some embodiments of the present invention, the co-solvent includes boric acid, and the mass fraction of the boric acid is 0.5% to 6%.

[0019] In some embodiments of the present invention, in the step of pressing, the pressing pressure is 0.5 MPa to 20 MPa.

[0020] In some embodiments of the present invention, the calcination temperature is 750° C. to 1050° C.; and / or the calcination time is 0.2 h to 3 h.

[0021] The present invention also provides a conductive porous ceramic prepared by the method for preparing conductive porous ceramics from solid waste materials as described above.

[0022] The present invention also provides an application of the conductive porous ceramic as described above, wherein the conductive porous ceramic is applied to the fields of electromagnetic shielding, wave absorbing materials, photoelectric catalysts, porous membrane materials, electronic atomizers, and solid capacitors.

[0023] The beneficial effects that can be achieved by the present invention are:

[0024] The present invention utilizes three solid waste resources, namely, desulfurization dust, waste glass and waste graphite, to prepare conductive porous ceramics, thereby realizing the coordinated treatment and resource utilization of multiple solid waste resources.

[0025] Based on the easy high-temperature sintering and molding characteristics of desulfurization dust and waste glass and the high conductivity of battery recycled graphite, the advantages and characteristics of various solid waste resources are combined to prepare conductive functional porous ceramics with adjustable permeability. The ceramics can be used in high-end application fields with certain requirements for conductivity, porous structure and strength, and have a wide range of uses. In addition, the preparation method of the present invention has the advantages of green and environmentally friendly raw materials, simple operation, low cost, and easy large-scale production, and has good practical application prospects.

[0026] In addition, the use of waste graphite can not only be used as a conductive additive to increase and regulate the conductivity of the prepared conductive porous ceramics, but also the oxidation and burning loss of part of the waste graphite during the high-temperature sintering process can be utilized as a pore-forming self-template, which can significantly increase and regulate the permeability of the conductive porous ceramics, reduce the use of additional pore-forming agents, and reduce costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0028] Figure 1 The figure is a schematic diagram of the preparation process of a conductive porous ceramic according to an embodiment of the present invention.

[0029] Figure 2 FIG. 1 is a schematic diagram of the appearance of a conductive porous ceramic according to an embodiment of the present invention.

[0030] Figure 3 FIG. 1 is a microscopic schematic diagram of a conductive porous ceramic according to an embodiment of the present invention.

[0031] Figure 4 FIG. 4 is another microscopic schematic diagram of a conductive porous ceramic according to an embodiment of the present invention.

[0032] Figure 5 FIG. 1 is an XRD analysis diagram of a conductive porous ceramic according to an embodiment of the present invention.

[0033] Figure 6 This is a comparison chart of the permeability of conductive porous ceramics according to an embodiment of the present invention.

[0034] Figure 7 The permeability comparison diagram of the conductive porous ceramic according to an embodiment of the present invention and the ceramic of the comparative example is shown in FIG.

[0035] Figure 8 This is another permeability comparison diagram of the conductive porous ceramic according to an embodiment of the present invention.

[0036] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0037] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] In the present invention, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0040] The present invention provides a method for preparing conductive porous ceramics from solid waste materials and the prepared conductive porous ceramics, Figure 1 , the preparation method comprises the following steps:

[0041] S10, mixing desulfurization dust, waste glass, waste graphite and a solvent to obtain a mixed powder;

[0042] S20, pressing the mixed powder into a mixed block;

[0043] S30, the mixed block is calcined to obtain a porous conductive ceramic.

[0044] The desulfurization dust in step S10 includes powdered solid waste generated by desulfurization of sulfur-containing flue gas discharged during the glass production process. The fuel and raw materials used in float glass production contain sulfur, which causes a large amount of SO in the flue gas discharged from the kiln. 2 In order to carry out flue gas desulfurization, soda lime is usually used for desulfurization operation, which will produce a large amount of powdery solid waste, namely the desulfurization dust in step S10. The main components of the desulfurization dust include at least one of calcium sulfate, calcium carbonate and calcium hydroxide.

[0045] The waste glass in step S10 includes glass discarded in the glass industry.

[0046] The waste graphite in step S10 may come from graphite in waste batteries, for example, waste graphite obtained by disassembling scrapped lithium batteries.

[0047] The desulfurization dust and waste glass of the present invention are easy to sinter and form, and the waste graphite has high conductivity. By combining the advantages and characteristics of the three solid wastes, conductive porous ceramics with adjustable permeability can be prepared. The conductive porous ceramics can be suitable for high-end application fields with certain requirements on conductivity, porous structure and strength, and have a wide range of uses.

[0048] In step S10, the desulfurization dust, waste glass, waste graphite and solvent can be mixed and then fully mixed by wet grinding, which is conducive to promoting the uniform mixing of the desulfurization dust, waste glass and waste graphite to obtain a conductive porous ceramic with uniform pores and better conductive properties.

[0049] In some embodiments, the particle size of desulfurized dust, waste glass, and waste graphite ranges from 50 μm to 300 μm, and can be any value in the range of 50 μm to 300 μm, such as 50 μm, 80 μm, 100 μm, 120 μm, 125 μm, 130 μm, 135 μm, 140 μm, 150 μm, 160 μm, 170 μm, 180 μm, 190 μm, 200 μm, 250 μm, 300 μm, etc. Under the above particle size range conditions, it is conducive to uniform mixing of the three solid wastes, thereby calcining to obtain a conductive porous ceramic with uniform component distribution, thereby improving the strength of the conductive porous ceramic and improving its conductivity and permeability.

[0050] Desulfurization dust and waste glass have the characteristics of being easy to sinter and form. By controlling the mass ratio of the two, the strength of the conductive porous ceramic can be adjusted and its permeability can be controlled. In some embodiments, the mass ratio of desulfurization dust and waste glass is (1:9) to (6:4), which can be any ratio in the range of (1:9) to (6:4), such as 1:9, 1:8, 1:7, 1:6, 1:5, 1:4, 1:3, 1:2, 1:1, 6:4, etc. Under the above ratio conditions, it is conducive to calcining to obtain a conductive porous ceramic with higher strength. Moreover, by appropriately increasing the proportion of waste glass, the permeability of the conductive porous ceramic can be controlled and improved.

[0051] The waste graphite in the three solid wastes can not only be used as a conductive additive to improve the conductive effect of the conductive porous ceramics, but also in the process of calcination, part of the waste graphite can be used as a pore-forming template with the high-temperature oxidation and burning process to form a porous structure and improve the permeability of the conductive porous ceramics. Therefore, the mass ratio of the waste graphite in the three solid wastes plays a role in regulating the conductivity and permeability of the conductive porous ceramics. In some embodiments, the total mass of the desulfurization dust and the waste glass and the mass ratio of the waste graphite are 100: (0.1-20), which can be any value in the range of 100: (0.1-20) such as 100: 0.1, 100: 0.5, 100: 1, 100: 5, 100: 10, 100: 15, 100: 20, etc. By adjusting the content of waste graphite, not only can the conductive porous ceramics be adjusted to have better conductivity, but also can be regulated to obtain better permeability, and a balance can be achieved between the conductive properties and the permeability. In this embodiment, as the graphite content increases, the permeability of the conductive porous ceramic is also improved, because graphite can not only be used as a conductive additive, but also the high-temperature oxidation and burning process of part of the waste graphite can be used as a pore-forming template to improve its permeability. Within the above ratio range, the conductive porous ceramic can be given better conductivity and its permeability can be properly controlled.

[0052] The co-solvent of the present invention can dissolve desulfurization dust, waste glass and waste graphite, and promote more uniform mixing of the above three solid wastes.

[0053] In some embodiments, the co-solvent includes at least one of boric acid and borax solution.

[0054] In some embodiments, the co-solvent includes boric acid, and the mass fraction of the boric acid is 0.5% to 6%, which can be any value in the range of 0.5% to 6%, such as 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, etc.

[0055] In some embodiments, the total mass of desulfurized dust, waste glass, and waste graphite and the solid-liquid ratio of the solvent are (5:1) to (1:1) (g / mL). In this embodiment, the solvent can dissolve the desulfurized dust, waste glass, and waste graphite to form a mixed powder with a certain fluidity, but the fluidity of the mixed powder will not be too strong due to too much solvent content, which is conducive to subsequent pressing and molding.

[0056] In the pressing step of the present invention, the magnitude of the pressing pressure has a certain influence on the permeability of the conductive porous ceramic. The greater the pressure, the stronger the mixed block before sintering, the less part burned during the calcination process, the lower the porosity of the conductive porous ceramic obtained, and the permeability is also weakened, but the strength of the conductive porous ceramic will be enhanced. When the pressing pressure is appropriately reduced, the mixed block before sintering is relatively loose, and the burned part increases during the calcination process. The conductive porous ceramic has more pores and the permeability is also enhanced, but the strength of the conductive porous ceramic will also be weakened. Therefore, the permeability and strength of the conductive porous ceramic can be adjusted by adjusting the pressing pressure.

[0057] In some embodiments, in the step of pressing and forming, the pressing pressure is 0.5MPa to 20MPa, and can be any value in the range of 0.5MPa to 20MPa, such as 0.5MPa, 1MPa, 5MPa, 10MPa, 15MPa, 20MPa, etc. In this embodiment, the appropriate pressure can not only press the mixed powder into shape, so that the conductive porous ceramic obtained after sintering has a certain strength, but also it is not easy to press the mixed block too hard due to excessive pressure, which is not conducive to calcination. Part of the waste graphite in the mixed block is easy to be burned away, and the porosity is increased, thereby achieving the effect of adjusting the permeability of the conductive porous ceramic.

[0058] During the calcination process, desulfurization dust and waste glass are easy to sinter and form under high temperature conditions, thereby improving the strength of the conductive porous ceramic, while waste graphite will be partially burned out during the high-temperature sintering process to form a porous structure, thereby improving the permeability of the conductive porous ceramic. In some embodiments, the calcination temperature is 750°C to 1050°C, for example, it can be any temperature in the range of 750°C to 1050°C, such as 750°C, 800°C, 850°C, 900°C, 950°C, 1000°C, 1050°C, etc., which can promote the sintering and forming of desulfurization dust and waste glass, and can also promote the burning out of part of the waste graphite to form a conductive porous ceramic with a porous structure. The conductive porous ceramic thus obtained has both good conductivity and strength, and a certain permeability, and reduces the use of pore-forming agents.

[0059] In some embodiments, the calcination time is 0.2h to 3h, and can be any value in the range of 0.2h to 3h, such as 0.2h, 0.5h, 1h, 1.5h, 2h, 2.5h, 3h, etc. Under the above calcination time conditions, it is beneficial to obtain conductive porous ceramics with stable structure, good strength, uniform porosity and good conductive properties.

[0060] The conductive porous ceramics prepared by the present invention can be applied to electromagnetic shielding, wave absorbing materials, photoelectric catalysts, porous membrane materials, electronic atomizers, solid-state capacitors and other fields.

[0061] The technical solution of the present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the following specific embodiments are only used to explain the present invention, and are not used to limit the present invention.

[0062] Example 1

[0063] The method for preparing conductive porous ceramics from solid waste materials in Example 1 has the following steps:

[0064] S10, weighing 2 g of desulfurization dust with a particle size range of 100 μm to 200 μm, 8 g of waste glass, and 1 g of waste graphite, adding 11 mL of a 3% by mass boric acid solution thereto, grinding and mixing thoroughly to obtain a mixed powder;

[0065] S20, the mixed powder of step S10 is pressed and molded at a pressure of 20 MPa to obtain a mixed block;

[0066] S30, placing the mixed block of step S20 into a sintering furnace and calcining at 950°C for 1 hour, and obtaining a conductive porous ceramic with a porous structure after cooling.

[0067] Example 2

[0068] Example 2: Conductive porous ceramics were prepared by referring to the preparation method of Example 1, except that the amount of waste graphite added was 0.05g, 0.1g, 0.2g, and 1g, respectively.

[0069] Example 3

[0070] Example 3 A conductive porous ceramic is prepared by referring to the preparation method of Example 1, except that in step S20, the solid block is formed by pressing at pressures of 10 MPa, 50 MPa, 100 MPa, and 20 MPa, respectively.

[0071] Comparative Example 1

[0072] Comparative Example 1: Ceramics were prepared by referring to the preparation method of Example 1, but the difference is that no waste graphite was added in step S10.

[0073] Characterization Test

[0074] The test objects are the conductive porous ceramics prepared in Example 1 and the ceramics prepared in Comparative Example 1.

[0075] 1. Appearance observation: Figure 2 This is a photo of the conductive porous ceramic prepared using the heart-shaped mold in Example 1.

[0076] 2. Microscopic observation: The results are as follows Figures 3 to 5 shown.

[0077] (1) The microstructure was observed by SEM electron microscope. Figure 3 ,Depend on Figure 3 It can be seen that the prepared conductive porous ceramics have rich pore characteristics.

[0078] (2) Through SEM mapping and EDS spectrum analysis, we can obtain Figure 4 ,Depend on Figure 4 It can be known that conductive porous ceramics are mainly composed of elements such as C, O, Na, Si, S, and Ca.

[0079] (3) Through XRD analysis, Figure 5 ,Depend on Figure 5 It can be seen that O, Na, and Si in the conductive porous ceramics mainly come from glass powder, O, S, and Ca come from desulfurization dust, and C mainly comes from waste graphite. This test can observe the diffraction peak of graphite in the conductive porous ceramic sample prepared by adding graphite, which further confirms the presence of graphite and is conducive to a significant increase in the conductivity of the ceramic.

[0080] In addition, this test also examined Example 1, in which the ceramic component without graphite addition did not contain graphite.

[0081] Penetration Testing

[0082] (1) The permeability of the conductive porous ceramics prepared at different ratios of desulfurization dust to waste glass was tested and analyzed. The test object was Example 1. The results are as follows: Figure 6 shown.

[0083] The test results show that with the increase of glass powder ratio, the permeability of conductive porous ceramics is significantly improved and the pores are increased. When the ratio of desulfurization dust to waste glass is reduced from 3:7 to 1:9 and the ratio of waste glass is increased, the permeability can be increased from 15L·min -1 MPa -1 Increase to 140L·min -1 MPa -1 .

[0084] (2) The permeability of the conductive porous ceramics prepared under different waste graphite addition conditions was tested and analyzed. The test objects were Example 2 and Comparative Example 1. The results are as follows: Figure 7 shown.

[0085] The test results show that with the increase of graphite content, the permeability of the conductive porous ceramic is also significantly improved, and the pores are increased. As the amount of graphite is increased from 0 in comparative example 1 to 0.05g, 0.1g, 0.2g, and 1g in embodiment 2, the permeability of the ceramic increases from 30L·min -1 MPa -1 Gradually increase to 90 L min -1 MPa -1 The main reason is that graphite can not only be used as a conductive additive, but also the high-temperature oxidation and burning process of part of the graphite can be used as a pore-forming self-template to improve the permeability of conductive porous ceramics.

[0086] (3) The permeability of the conductive porous ceramics obtained under different pressing pressure conditions was also tested and analyzed. The test object was Example 3. The results are as follows: Figure 8 shown.

[0087] The test results show that the permeability of conductive porous ceramics is significantly improved with the decrease of pressing pressure, and the permeability can be increased from 50L·min -1 MPa -1 Increased to 172L·min -1 MPa -1 Although the porosity increases with the decrease of pressing pressure, the strength of ceramics will be reduced to a certain extent.

[0088] Resistance test

[0089] The conductivity test was conducted on the samples prepared by the comparative example 1 without adding graphite and the four samples of the embodiment 2 with different amounts of graphite added. The results are shown in Table 1.

[0090] Table 1

[0091]

[0092] As shown in Table 1, the sample prepared without adding graphite in Comparative Example 1 is not conductive, while the sample prepared in Example 2 with 0.05 g of graphite added gives the porous ceramic conductivity, with a resistance of 13 Ω·mm. -1 In combination with Examples 2-1 to 2-4, it can be seen that further increasing the graphite content helps to reduce the resistance value and improve the conductivity of the conductive porous ceramic. When the graphite content increases to 1g, the resistance value can be reduced to 4Ω·mm -1 , the conductivity of porous ceramics is significantly improved.

[0093] The above results indicate that the method for preparing conductive porous ceramics from solid waste materials of the present invention can simply and effectively utilize three solid waste resources to obtain porous ceramics with conductivity and good permeability. In addition, the permeability and conductivity of the prepared porous ceramics can be regulated by the content of the three solid waste raw materials and the pressing pressure. It is expected to be applied in many fields such as electromagnetic shielding and absorbing materials, photoelectric catalysts, porous membrane materials, electronic atomizers, solid-state capacitors, etc.

[0094] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for preparing conductive porous ceramics from solid waste materials, characterized in that: The following steps are involved: Mixing desulfurization dust, waste glass, waste graphite and a solvent to obtain a mixed powder; Pressing the mixed powder into a mixed block; The mixed block is calcined to obtain a porous conductive ceramic.

2. The method for preparing conductive porous ceramics from solid waste materials according to claim 1, characterized in that: The desulfurization dust includes at least one of calcium sulfate, calcium carbonate and calcium hydroxide; And / or, the waste graphite includes graphite recovered from waste batteries.

3. The method for preparing conductive porous ceramics from solid waste materials according to claim 1, characterized in that: The particle size range of the desulfurization dust, waste glass and waste graphite is 50 μm to 300 μm.

4. The method for preparing conductive porous ceramics from solid waste materials according to claim 1, characterized in that: The mass ratio of the desulfurization dust to the waste glass is (1:9) to (6:4); And / or, the mass ratio of the total mass of the desulfurization dust and waste glass to the waste graphite is 100:(0.1-20); And / or, the solid-to-liquid ratio of the total mass of the desulfurization dust, waste glass, waste graphite and the co-solvent is (5:1) to (1:1) (g / mL).

5. The method for preparing conductive porous ceramics from solid waste materials according to claim 1, characterized in that: The co-solvent includes at least one of boric acid and borax solution.

6. The method for preparing conductive porous ceramics from solid waste materials according to claim 5, characterized in that: The co-solvent comprises boric acid, and the mass fraction of the boric acid is 0.5% to 6%.

7. The method for preparing conductive porous ceramics from solid waste materials according to claim 1, characterized in that: In the step of pressing and molding, the pressing pressure is 0.5 MPa to 20 MPa.

8. The method for preparing conductive porous ceramics from solid waste materials according to claim 1, characterized in that: The calcination temperature is 750° C. to 1050° C.; and / or the calcination time is 0.2 h to 3 h.

9. A conductive porous ceramic prepared by the method for preparing conductive porous ceramics from solid waste materials as claimed in any one of claims 1 to 8.

10. An application of the conductive porous ceramic according to claim 9, characterized in that: The conductive porous ceramic is applied to the fields of electromagnetic shielding, wave absorbing materials, photoelectric catalysts, porous membrane materials, electronic atomizers and solid capacitors.

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