Device and method for removing organic matter in sodium chloride waste salt by high-temperature oxidation

Abstract

This invention provides a high-temperature oxidation removal device and method for organic matter removal from sodium chloride waste salt, relating to the technical field of organic matter removal from sodium chloride waste salt. The device includes: a fluidized bed comprising a shell, within which are arranged a plurality of vertically spaced porous trays and a plurality of internal components coated with a catalyst; a discharge pipe at the lower end of the shell; an air supply assembly connected to the lower end of the fluidized bed and used to supply air to the fluidized bed; a preheating oxidizer positioned above the fluidized bed and connected to its upper end; and a feeding assembly connected to the preheating oxidizer. The invention proposes using high-temperature oxidation to remove organic matter from sodium chloride waste salt, which improves thermal efficiency, meets removal quality requirements, and reduces costs.

Description

Technical Field

[0001] This invention belongs to the technical field of organic matter removal from sodium chloride waste salt, and more specifically, relates to a high-temperature oxidation removal device and method for organic matter removal from sodium chloride waste salt. Background Technology

[0002] The organic chlorination process generates waste sodium chloride containing organic impurities as a byproduct. With industry development, the volume of this waste salt is increasing. Due to its difficulty in treatment and high environmental risks, it has been officially included in the "National Hazardous Waste List" and is managed and disposed of as hazardous waste. Furthermore, the lack of recycling of this waste sodium chloride leads to resource waste. Therefore, purifying and returning this waste sodium chloride to the salt chemical production process as a raw material to achieve the recycling of chlorine is the best way to achieve harmless treatment of waste salt. Currently, the largest resource utilization direction for purified industrial waste salt is its use as raw material in the production of caustic soda and soda ash, with caustic soda accounting for approximately 60% of total production capacity. For the waste salt generated as a byproduct of the organic chlorination process, the main impurities are residual organic matter. For sodium chloride used in ion-exchange membrane caustic soda production, the organic impurities, calculated as total carbon content, should not exceed 20 mg / kg NaCl.

[0003] Currently, the main methods for treating sodium chloride waste salt containing organic impurities are as follows: salt washing, which involves washing the waste salt with water or organic solvents to remove organic matter, but this method is only suitable for treating waste salt with a single type and a small amount of impurities; pyrolysis carbonization, which involves heating (at a temperature below the melting point of the salt) to decompose and remove organic matter, and the salt can be purified by subsequent dissolution and crystallization, but it has problems such as difficulty in controlling the carbonization temperature and the softening of the salt surface, easy adhesion to the carbonization equipment, and impact on continuous production; and high-temperature melting treatment, which involves heating the salt slag to a liquid state at a high temperature of 800-1200℃ to remove organic matter, but the operating cost and equipment requirements are relatively high, and the fluidity of the high-temperature molten salt is poor. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing a high-temperature oxidation removal device and method for organic matter removal from sodium chloride waste salt. This invention proposes to remove organic matter from sodium chloride waste salt through high-temperature oxidation, which can improve thermal efficiency, meet removal quality requirements, and reduce costs.

[0005] To achieve the above objectives, the present invention provides a high-temperature oxidation removal device for organic matter in sodium chloride waste salt, the device comprising: A fluidized bed, comprising a shell, wherein a plurality of porous trays arranged vertically at intervals and a plurality of internal components coated with catalyst are provided inside the shell, and a discharge pipe is provided at the lower end of the shell; An air supply assembly is connected to the lower end of the fluidized bed and is used to supply air to the fluidized bed. A preheating oxidizer is disposed above the fluidized bed and connected to the upper end of the fluidized bed; A feeding assembly is connected to the preheating oxidizer.

[0006] Optionally, a gas distribution plate is provided below the bottommost porous tray, a powder overflow pipe is vertically provided on each porous tray, and a feed pipe is provided above the topmost porous tray. The feed pipe passes through the top surface of the fluidized bed and is connected to the preheating oxidizer.

[0007] Optionally, a cyclone separator is provided at the upper end of the fluidized bed, and the preheating oxidizer includes multi-stage cyclones. The lower port of the last-stage cyclone is connected to the upper end of the feed pipe, the upper port of the first-stage cyclone is connected to the feeding assembly, the side port of the last-stage cyclone is connected to the upper end of the cyclone separator that penetrates the top surface of the fluidized bed, and the upper port of each of the remaining stages of the cyclone is connected to the side port of the cyclone of the stage above it.

[0008] Optionally, the air supply assembly includes a cold air supply end and a hot air supply end. The bottom and side of the lower end of the fluidized bed are respectively provided with a bottom air inlet and a side air inlet. The cold air supply end is connected to the bottom air inlet, and the hot air supply end is connected to the side air inlet and the side opening of the last stage cyclone.

[0009] Optionally, the feeding assembly includes an industrial waste salt storage tank and a screw feeder, wherein the inlet and outlet of the screw feeder are respectively connected to the side opening of the industrial waste salt storage tank and the first-stage cyclone.

[0010] Optionally, the gas supply assembly includes: A first air blower, the outlet of which is connected to a burner, and the burner is connected to a gas pipeline; An air heater, wherein the burner inlet of the air heater is connected to the burner outlet, and a heat exchange tube is provided inside the air heater; The second air blower has an inlet connected to an air filter and an outlet connected to the air inlet of the heat exchange tube and a cold air supply line. The cold air supply line forms the cold air supply end, and the air outlet of the heat exchange tube forms the hot air supply end. The cold air supply line is connected to the bottom air inlet. The hot air supply end is connected to the side opening and the side air inlet of the final stage cyclone separator through the first and second hot air supply lines, respectively.

[0011] Optionally, the internal component includes at least two pipes arranged side by side at intervals, adjacent pipes are connected by a U-shaped connecting pipe to form a serpentine structure, and the surfaces of the pipes and the connecting pipe are provided with spirally wound metal fins; the surface of the internal component is loaded with a porous ceramic catalytic coating with cordierite micro powder as the skeleton and iron-praseodymium-gadolinium composite oxide as the active component.

[0012] Optionally, the internal component with the catalyst coating is an internal component prepared by the following preparation method, which includes: Step 1: Dissolve ferric nitrate, praseodymium nitrate and gadolinium nitrate in water, add citric acid as a complexing agent, and form a homogeneous metal complex sol under heating and stirring conditions; Step 2: Add aluminum dihydrogen phosphate inorganic binder solution and cordierite micro powder aggregate to the sol obtained in Step 1, and disperse by ball milling to prepare a thixotropic composite ceramic slurry with a solid content of 40-60 wt%. Step 3: The internal components are roughened by sandblasting, then cleaned and dried; Step 4: Immerse the internal components treated in Step 3 into the slurry prepared in Step 2, and form a uniform wet film at a lifting speed of 5-10 mm / min, then dry. Step 5: The internal components obtained in Step 4 are calcined in sections to obtain the internal components with the catalyst coating. The conditions for the section calcination include: first drying at 80-150℃ for 1-3 hours, then heating at 1-2℃ / min to 300-400℃ and holding for 1-2 hours, and finally heating at 3-5℃ / min to 700-900℃ and holding for 2-4 hours.

[0013] This invention also provides a method for high-temperature oxidation removal of organic matter from sodium chloride waste salt, utilizing the aforementioned high-temperature oxidation removal device for organic matter from sodium chloride waste salt, the method comprising: Gas is supplied to the fluidized bed through the gas supply assembly to preheat the fluidized bed and the preheating oxidizer; When the gas temperature at the lower end of the preheating oxidizer reaches the set temperature, the feed is fed through the feeding assembly, and the gas flow rate into the fluidized bed is adjusted to form the set empty tower gas velocity in the fluidized bed and the set gas velocity at the upper end of the preheating oxidizer, so that the waste salt powder particles enter the fluidized bed through the preheating oxidizer and flow downward in the fluidized bed in a fluidized state. Adjusting the air supply parameters of the air supply component cools the lower end of the fluidized bed, reduces the temperature of the salt powder discharged from the fluidized bed, and recovers heat. Adjust the gas supply parameters of the gas supply component to raise the hot spot temperature between the second and third porous trays of the fluidized bed to the operating temperature. Adjust the feed rate of the feeding component to ensure that the waste salt powder particles have a set residence time in the fluidized bed. The gas at the operating temperature comes into contact with the waste salt powder particles in the fluidized state, so that the organic matter in the waste salt powder particles is oxidized, thereby achieving the standard for the total organic carbon in the waste salt powder particles.

[0014] Optionally, it also includes: when the gas temperature at the lower end of the preheating oxidizer is lower than the set temperature, adjusting the gas supply mode of the gas supply component, and using the gas supply component to supply gas to the lower end of the preheating oxidizer to increase the gas temperature at the lower end of the preheating oxidizer, so as to maintain the gas temperature at the lower end of the preheating oxidizer at the set temperature.

[0015] This invention provides a high-temperature oxidation removal device and method for organic matter in sodium chloride waste salt. Its advantages are as follows: The device is equipped with a multi-layer porous tray fluidized bed, and a preheating oxidizer is installed above the fluidized bed. The waste salt particles are pretreated by recovering the high-temperature tail gas from the fluidized bed, which not only achieves heat reuse and improves heat utilization efficiency, but also improves the treatment effect by drying and pre-oxidizing the waste salt particles entering the fluidized bed. Gas is supplied to the fluidized bed and preheating oxidizer through a gas supply component, causing the waste salt particles to form a fluidized state within the fluidized bed, resulting in good contact with the heating gas. The average residence time of the waste salt particles in the fluidized bed can be easily adjusted by regulating the gas supply parameters of the gas supply component, providing high operational flexibility. Simultaneously, by incorporating multiple internal components with catalyst coatings, a catalytic effect is introduced, reducing the temperature required for organic matter oxidation and lowering the reaction temperature. This effectively resolves the contradiction between the thoroughness of the high-temperature oxidation reaction and the scaling and clogging of the equipment caused by waste salt melting, greatly improving the treatment effect and production efficiency.

[0016] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0017] The above and other objects, features and advantages of the present invention will become more apparent from the more detailed description of exemplary embodiments of the invention in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments of the invention.

[0018] Figure 1 A schematic diagram of a high-temperature oxidation removal device for organic matter in sodium chloride waste salt according to an embodiment of the present invention is shown.

[0019] Figure 2 A schematic diagram of the internal components of a high-temperature oxidation removal device for organic matter in sodium chloride waste salt according to an embodiment of the present invention is shown.

[0020] Figure 3 A flowchart of a method for high-temperature oxidation removal of organic matter from sodium chloride waste salt according to an embodiment of the present invention is shown.

[0021] Explanation of reference numerals in the attached figures: 1. Industrial waste salt storage tank; 2. Screw feeder; 3. First air blower; 4. Second air blower; 5. Air filter; 6. Air heater; 7. Preheating oxidizer; 8. Fluidized bed; 9. Burner; 10. Internal components with catalyst coating; 601. Air inlet; 602. Air outlet; 603. Combustion gas inlet; 604. Combustion exhaust gas outlet; 701. First-stage cyclone; 702. Second-stage cyclone; 703. Third-stage cyclone; 704. Fourth-stage cyclone; 800. Shell; 801. Bottom air inlet; 802. Discharge pipe; 803. Gas distribution plate; 804. Perforated tray; 805. Powder overflow pipe; 806. Cyclone separator; 807. Feed pipe; 808. Side air inlet; 1001, First valve; 1002, Second valve; 1003, Third valve; A. Raw material waste salt powder; B. Process air; C. Natural gas; D. Combustion air; E. Combustion exhaust gas; F. Salt product powder; G. Process exhaust gas. Detailed Implementation

[0022] Preferred embodiments of the invention will now be described in more detail. While preferred embodiments of the invention are described below, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0023] like Figure 1 As shown, the present invention provides a high-temperature oxidation removal device for organic matter in sodium chloride waste salt, the device comprising: Fluidized bed 8 includes a shell 800, and a plurality of porous trays 804 arranged vertically at intervals and a plurality of internal components 10 with catalyst coating are provided inside the shell 800. A discharge pipe 802 is provided at the lower end of the shell 800. An air supply assembly is connected to the lower end of the fluidized bed 8 and is used to supply air to the fluidized bed 8. Preheating oxidizer 7 is located above the fluidized bed 8 and connected to the upper end of the fluidized bed 8; The feeding assembly is connected to the preheating oxidizer 7.

[0024] Specifically, to remove organic matter from sodium chloride waste salt through high-temperature oxidation, which can improve thermal efficiency, meet removal quality requirements, and reduce costs, the high-temperature oxidation removal device for organic matter in sodium chloride waste salt provided by this invention is equipped with a multi-layer porous tray 8 fluidized bed 8, and a preheating oxidizer 7 is installed above the fluidized bed 8. The waste salt powder is pretreated by recovering the high-temperature tail gas from the fluidized bed 8, which not only realizes heat reuse and improves heat utilization rate, but also improves the treatment effect by drying and pre-oxidizing the waste salt powder entering the fluidized bed 8. The components supply air to the fluidized bed 8 and the preheating oxidizer 7, causing the waste salt particles to form a fluidized state within the fluidized bed 8, resulting in good contact with the heated gas. The average residence time of the waste salt particles in the fluidized bed 8 can be easily adjusted by regulating the air supply parameters of the air supply components, providing high operational flexibility. At the same time, by setting multiple internal components 10 with catalyst coatings, a catalytic effect is introduced, reducing the temperature required for the oxidation of organic matter and lowering the reaction temperature. This effectively resolves the contradiction between the thoroughness of high-temperature oxidation reaction and the scaling and clogging of the equipment caused by the melting of waste salt, greatly improving the treatment effect and production efficiency.

[0025] Optionally, a gas distribution plate 803 is provided below the bottommost porous tray 804, and a powder overflow pipe 805 is vertically provided on each porous tray 804. A feed pipe 807 is provided above the topmost porous tray 804, and the feed pipe 807 penetrates the top surface of the fluidized bed 8 and is connected to the preheating oxidizer 7.

[0026] Specifically, each porous tray 804 is provided with a powder overflow pipe 805, which is made of a cylindrical tube and a tapered funnel connected from top to bottom by welding; an internal component 10 with a catalyst coating is provided between each porous tray 804; the feed pipe 807 penetrates the top surface of the shell 800 of the fluidized bed 8 and extends downward into the interior of the fluidized bed 8, and its upper end is connected to the lower end of the preheating oxidizer 7.

[0027] Optionally, a cyclone separator 806 is provided at the upper end of the fluidized bed 8, and the preheating oxidizer 7 includes multi-stage cyclones. The lower port of the last-stage cyclone is connected to the upper end of the feed pipe 807, the upper port of the first-stage cyclone is connected to the feeding assembly, the side port of the last-stage cyclone is connected to the upper end of the cyclone separator 806 that penetrates the top surface of the fluidized bed 8, and the upper port of each of the remaining cyclones is connected to the side port of the cyclone of the previous stage.

[0028] Specifically, a gas distribution plate 803 is installed inside the lower end of the fluidized bed 8, and a cyclone separator 806 is installed inside the upper end of the fluidized bed 8. The outlet pipe of the cyclone separator 806 passes through the top surface of the fluidized bed 8 and is connected to the gas inlet at the lower end of the pre-oxidizer. The preheating oxidizer 7 is equipped with multiple cyclone tubes, which can be connected in series or in parallel. When connected in series, the upper port of each cyclone tube, i.e., the air outlet, is connected to the lower port side port, i.e., the feed inlet, of the cyclone tube above it. For example, it includes a first-stage cyclone tube 701, a second-stage cyclone tube 702, a third-stage cyclone tube 703, and a fourth-stage cyclone tube 704. The air inlet pipe of the first-stage cyclone tube 701 is equipped with a material inlet and is connected to the feeding assembly. The air inlet pipe of the last-stage cyclone tube is connected to the upper end of the cyclone separator 806 and can also be connected to the gas supply assembly.

[0029] Furthermore, the pre-oxidizer has 2 to 8 cyclone stages, selected and configured according to the TOC content of the waste salt powder and the amount of heat required for the pre-oxidation stage; preferably, it has 4 cyclone stages in series, namely, stage 1 cyclone 701, stage 2 cyclone 702, stage 3 cyclone 703, and stage 4 cyclone 704; the multi-layer chemical bed has 4 to 8 layers, with a diameter of 0.3 to 0.7 m, and the distance between two adjacent porous trays 804 is 500 to 2000 mm; the cylindrical cross-section of the powder overflow pipe 805 is... The ratio of the area to the cross-sectional area of ​​the bed is 0.02-0.10. The distance between the top of the cylindrical tube of the powder overflow pipe 805 and the porous tray 804 of the same layer is 100-800mm. The distance between the bottom of the condensing funnel of the powder overflow pipe 805 and the porous tray 804 of the next layer is 50-400mm. The ratio of the bottom constriction diameter of the powder overflow pipe 805 to the upper pipe diameter is 0.40-0.66. The porosity of each porous tray 804 is 0.5-5.0%, and the porosity of the gas distribution plate 803 is 0.2-2.0%.

[0030] Optionally, the air supply assembly includes a cold air supply end and a hot air supply end. The bottom and side of the lower end of the fluidized bed 8 are respectively provided with a bottom air inlet 801 and a side air inlet 808. The cold air supply end is connected to the bottom air inlet 801, and the hot air supply end is connected to the side air inlet 808 and the side opening of the last stage cyclone.

[0031] Specifically, the bottom shell 800 of the fluidized bed 8 is provided with a bottom air inlet 801, and the side air inlet 808 of the fluidized bed 8 is connected to an air inlet pipe, which is connected to the wall of the shell 800 below the second-third layer of porous tower plates 804. The air supply component supplies cooling air and heating air through its cold air supply end and hot air supply end, respectively. The cooling air can enter the fluidized bed 8 through the bottom air inlet 801 to cool down the salt product powder F inside the lower end of the fluidized bed 8 and recover its heat to improve energy utilization. The heating air can be controlled by a valve to enter the hot spot position at the lower end of the fluidized bed 8 through the side air inlet 808, or enter the side opening of the last stage cyclone to supplement heat for preheating oxidation and ensure the preheating and preoxidation effect.

[0032] Optionally, the feeding assembly includes an industrial waste salt storage tank 1 and a screw feeder 2, with the inlet and outlet of the screw feeder 2 connected to the side openings of the industrial waste salt storage tank 1 and the first-stage cyclone, respectively.

[0033] Specifically, the bottom outlet of the industrial waste salt storage tank 1 is fixedly connected to the inlet of the screw feeder 2, and the outlet of the screw feeder 2 is connected to the side outlet of the first-stage cyclone of the preheating oxidizer 7 to realize feeding.

[0034] Optionally, the gas supply assembly includes: The outlet of the first air blower 3 is connected to the burner 9, and the burner 9 is connected to a gas pipeline. Air heater 6, the inlet of burner 9 of air heater 6 is connected to the outlet of burner 9, and heat exchange tubes are installed inside air heater 6; The second air blower 4 has an inlet connected to an air filter 5 and an outlet connected to the air inlet 601 of the heat exchange tube and a cold air supply pipeline. The cold air supply pipeline forms a cold air supply end, and the air outlet 602 of the heat exchange tube forms a hot air supply end. The cold air supply pipeline is connected to the bottom air inlet 801, and the hot air supply end is connected to the side opening and side air inlet 808 of the final stage cyclone separator through the first hot air supply pipeline and the second hot air supply pipeline, respectively.

[0035] Specifically, the burner 9 is equipped with a natural gas inlet pipe, the burner 9 is installed on the bottom side of the air heater 6, and the top of the air heater 6 is equipped with a combustion exhaust gas outlet 604; the first hot air supply pipeline, the second hot air supply pipeline and the cold air supply pipeline are respectively equipped with a first valve 1001, a second valve 1002 and a third valve 1003, so as to facilitate the adjustment of gas supply parameters and gas supply mode.

[0036] Optionally, the internal component includes at least two pipes arranged side by side at intervals, with adjacent pipes connected by U-shaped connecting pipes to form a serpentine structure, and the surfaces of the pipes and connecting pipes are provided with spirally wound metal fins; the surface of the internal component is loaded with a porous ceramic catalytic coating with cordierite micro powder as the skeleton and iron-praseodymium-gadolinium composite oxide as the active component.

[0037] Specifically, such as Figure 2 As shown, a catalytic coating is provided on the outer surface of the finned inner component; a Fe-Pr-Gd / cordierite composite ceramic functional layer with both high chlorine resistance and thermomechanical stability is loaded in situ on the surface of the inner component; by utilizing the synergistic mechanism of Gd lattice pinning and Fe-Pr dual valence change, a stable lattice oxygen supply is ensured under high-temperature conditions containing chlorine, overcoming the defects of traditional catalysts that are prone to chlorine poisoning and lattice collapse; combined with the cordierite low-expansion framework and the dense interpenetrating network and multi-level pore structure formed by the self-propagating combustion pore-forming process, the thermal stress caused by the mismatch of thermal expansion coefficients is effectively reduced, and while significantly increasing the reaction specific surface area, the technical problem of easy cracking and peeling of the coating under severe thermal shock is fundamentally solved.

[0038] Furthermore, the internal components are made of 2520 heat-resistant steel with a pipe diameter of 10-30mm. The fins are welded around the steel pipe, and the connecting pipe length is 0.25-0.6m.

[0039] Optionally, the internal component 10 with the catalyst coating is an internal component prepared by the following preparation method, which includes: Step 1: Dissolve ferric nitrate, praseodymium nitrate and gadolinium nitrate in water, add citric acid as a complexing agent, and form a homogeneous metal complex sol under heating and stirring conditions; Step 2: Add aluminum dihydrogen phosphate inorganic binder solution and cordierite micro powder aggregate to the sol obtained in Step 1, and disperse by ball milling to prepare a thixotropic composite ceramic slurry with a solid content of 40-60 wt%. Step 3: The internal components are roughened by sandblasting, then cleaned and dried; Step 4: Immerse the internal components treated in Step 3 into the slurry prepared in Step 2, and form a uniform wet film at a lifting speed of 5-10 mm / min, then dry. Step 5: The internal components obtained in Step 4 are calcined in sections to obtain the internal components with the catalyst coating. The conditions for the section calcination include: first drying at 80-150℃ for 1-3 hours, then heating at 1-2℃ / min to 300-400℃ and holding for 1-2 hours, and finally heating at 3-5℃ / min to 700-900℃ and holding for 2-4 hours.

[0040] In this invention, in step five, the first stage involves drying at 80-150℃ for 1-3 hours to remove free water; the second stage involves heating at 1-2℃ / min to 300-400℃ and holding for 1-2 hours to initiate a sol-gel in-situ self-propagating combustion pore-forming reaction; and the third stage involves heating at 3-5℃ / min to 700-900℃ and holding for 2-4 hours to cure the adhesive and form a cordierite-reinforced iron-praseodymium-gadolinium composite oxide ceramic coating.

[0041] Specifically, the preparation method includes the following steps: Step 1: Dissolve ferric nitrate, praseodymium nitrate and gadolinium nitrate in deionized water according to stoichiometric ratio, add complexing agent citric acid, and form a homogeneous metal complex sol under heating and stirring conditions; Step 2: Add aluminum dihydrogen phosphate inorganic binder solution and cordierite micro powder aggregate to the sol obtained in Step 1, and disperse by ball milling to prepare a thixotropic composite ceramic slurry with a solid content of 40-60 wt%. Step 3: Roughen the internal components of the fins by sandblasting, clean and dry them for later use; Step 4: Immerse the pretreated finned internal components into the slurry from Step 2, and form a uniform wet film at a lifting speed of 5-10 mm / min. Step 5: Calcination in stages according to the following procedure: First stage: Dry at 80-150℃ for 1-3 hours to remove free water; Second stage: Increase the temperature to 300-400℃ at 1-2℃ / min and hold for 1-2 hours to initiate the sol-gel in-situ self-propagating combustion pore-forming reaction; Third stage: Increase the temperature to 700-900℃ at 3-5℃ / min and hold for 2-4 hours to cure the binder and form a cordierite-reinforced iron-praseodymium-gadolinium (Fe-Pr-Gd) composite oxide ceramic coating.

[0042] Further, in step one, the molar ratio of praseodymium nitrate, gadolinium nitrate, and ferric nitrate is (0.7-0.9):(0.1-0.3):1, and the molar content of the complexing agent citric acid is 1.0-1.5:1 to the total molar amount of praseodymium ions, gadolinium ions, and ferric ions; in step two, the average particle size of cordierite powder is 1-5 μm, and the mass ratio of cordierite powder to the theoretically generated metal oxide in the sol of step one is 0.8-2.0:1; the mass ratio of the amount of aluminum dihydrogen phosphate solution added to the mass ratio of dry matter in the sol of step one is 0.4-0.6:1; in step three, the surface roughness Ra of the substrate after sandblasting is 3-5 μm; in step five, the thickness of the catalyst coating is controlled at 30-100 μm.

[0043] like Figure 3 As shown, the present invention also provides a method for high-temperature oxidation removal of organic matter from sodium chloride waste salt, utilizing the above-mentioned high-temperature oxidation removal device for organic matter from sodium chloride waste salt, the method comprising: Gas is supplied to the fluidized bed 8 through the gas supply assembly to preheat the fluidized bed 8 and the preheating oxidizer 7; When the gas temperature at the lower end of the preheating oxidizer 7 reaches the set temperature, the feed is fed through the feeding assembly, and the gas flow rate entering the fluidized bed 8 is adjusted to form the set empty tower gas velocity in the fluidized bed 8 and the set gas velocity at the upper end of the preheating oxidizer 7, so that the waste salt powder particles enter the fluidized bed 8 through the preheating oxidizer 7 and flow downward in the fluidized state in the fluidized bed 8. Adjust the air supply parameters of the air supply component to cool the lower end of the fluidized bed 8, reduce the temperature of the salt powder discharged from the fluidized bed 8, and recover heat; Adjust the gas supply parameters of the gas supply component to raise the hot spot temperature between the second and third porous trays 804 in the fluidized bed 8 to the operating temperature. Adjust the feed rate of the feeding component to ensure that the waste salt powder particles have a set residence time in the fluidized bed 8. The gas at the operating temperature comes into contact with the waste salt powder particles in the fluidized state, so that the organic matter in the waste salt powder particles is oxidized, thereby achieving the standard for the total organic carbon content in the waste salt powder particles.

[0044] Optionally, it also includes: when the gas temperature at the lower end of the preheating oxidizer 7 is lower than the set temperature, adjusting the gas supply mode of the gas supply component, and using the gas supply component to supply gas to the lower end of the preheating oxidizer 7 to increase the gas temperature at the lower end of the preheating oxidizer 7, so as to maintain the gas temperature at the lower end of the preheating oxidizer 7 at the set temperature.

[0045] Specifically, the steps of the high-temperature oxidation method for removing organic matter from sodium chloride waste salt are as follows: S1: Open the valves on the gas pipeline and air pipeline connected to the burner 9, and open the first air blower 3. Natural gas C and combustion air D enter the burner 9 to ignite the burner 9 and generate combustion gas. The combustion gas enters the air heater 6 through the combustion gas inlet 603. After the temperature inside the air heater 6 reaches 150°C, turn on the second air blower 4. Process air B enters the heat exchange tube of the air heater 6 from the air filter 5 through the second air blower 4. The high-temperature combustion gas ejected from the burner 9 in the air heater 6 exchanges heat with the process air B in the heat exchange tube to obtain high-temperature process air B. Then, it enters the second bed layer at the bottom of the fluidized bed 8 through the first valve 1001 and the air inlet pipe to preheat the fluidized bed 8 and the pre-oxidizer. The combustion exhaust gas E after heat exchange is discharged from the combustion exhaust gas E outlet 604.

[0046] S2: When the gas temperature in the gas inlet pipe of the final stage cyclone of the pre-oxidizer reaches 300℃, turn on the screw feeder 2 and add the raw material waste salt powder A to the material inlet on the air inlet pipe of the first stage cyclone 701 of the pre-oxidizer through the material inlet; by adjusting the second air blower 4 and the first valve 1001, regulate the flow rate of hot air entering the main bed layer of the fluidized bed 8 to ensure the air velocity requirements of the empty tower in the second and above layers of the fluidized bed 8 and the air velocity requirements in the gas inlet pipe of the final stage cyclone; the waste salt powder enters from the side opening of the first stage cyclone 701 and falls from the lower port of the final stage cyclone into the feed pipe 807 at the top of the fluidized bed 8; the waste salt powder entering the porous tray 804 is in a fluidized state and flows from top to bottom between the porous trays 804 in the fluidized bed 8 through the powder overflow pipe 805.

[0047] S3: Open and adjust the third valve 1003, cold air enters the first layer at the bottom of the fluidized bed 8, maintaining the air velocity in this layer at 0.1~0.2m / s, fluidizing the hot salt in the first layer while cooling it down, reducing the temperature of the salt powder exiting the fluidized bed 8. At the same time, the cold air is heated and enters the second layer at the bottom of the fluidized bed 8 to recover the heat from the hot salt.

[0048] S4: Adjust the air flow rate and natural gas C flow rate entering the burner 9, and raise the hot spot temperature of the second and third layers of the fluidized bed 8 to the operating temperature through heating and heat exchange by the air heater 6; adjust the feed rate of the screw feeder 2 to change the residence time of the waste salt powder in the fluidized bed 8, and make the fluidized bed 8 achieve stable operation; on the porous trays 804 of each stage of the fluidized bed 8, the high temperature air and sodium chloride salt are fully in contact in the fluidized state, so that most of the organic impurities in the sodium chloride salt react with oxygen at high temperature and are oxidized, so as to meet the TOC requirements of the salt powder; process tail gas G is discharged from the upper port of the first stage cyclone 701 of the pre-oxidizer; the cooled salt product powder F is discharged through the discharge pipe 802.

[0049] S5: When the temperature at the gas inlet pipe of the final stage cyclone is less than 300℃, open and adjust the second valve 1002 to allow some high-temperature air to directly enter the gas inlet pipe of the final stage cyclone and maintain the temperature of the gas inlet pipe of the final stage cyclone at 300℃.

[0050] Furthermore, the initial feed moisture content of raw material waste salt powder A is 5-10%, and the TOC concentration is >2000ppm; the air pressure of the second air blower 4 is 10-35kPa; the hot spot temperature of fluidized bed 8 is 550-700℃; the residence time of raw material waste salt powder A in the high-temperature multi-layer fluidized bed 8 is 3-15min; under operating conditions, the empty tower gas velocity in each layer of fluidized bed 8 is 0.3-0.8m / s, and the gas velocity in the gas inlet pipe of the final stage cyclone is >20m / s.

[0051] Example 1

[0052] The preheating oxidizer 7 is equipped with four cyclone separators connected in series; the fluidized bed 8 has a shell 800 with four layers and a diameter of 0.3m. Inside the shell 800, three layers of porous trays 804 are evenly distributed from top to bottom, with a distance of 1800mm between adjacent layers of porous trays 804. The porosity of each layer of porous trays 804 is 0.5%. Powder overflow pipes 805 are installed on the porous trays 804. The ratio of the cylindrical cross-sectional area of ​​the powder overflow pipe 805 to the cross-sectional area of ​​the bed is 0.03, and the ratio of the bottom constriction diameter to the upper pipe diameter is 0.5. The top of the cylindrical part of the powder overflow pipe 805 is 800mm from the porous tray 804 of the same layer, and the bottom of the constriction funnel of the powder overflow pipe 805 is 80mm from the lower porous tray. The distance between 4 is 400mm; the bottom shell 800 wall of the lowest porous tray 804 of the fluidized bed 8 is connected to the bottom air inlet 801, and a gas distribution plate 803 is provided in the shell 800 between the bottom air inlet 801 and the lowest porous tray 804 of the fluidized bed 8, with an opening ratio of 0.2%; the side air inlet 808 of the fluidized bed 8 is connected to the second layer of the fluidized bed 8, and an internal component 10 with a catalyst coating is provided between each porous tray 804; a cyclone separator 806 is provided at the top of the fluidized bed 8, and the outlet pipe of the cyclone separator 806 is connected to the gas inlet at the bottom of the preheating oxidizer 7, for discharging the high-temperature air in the shell 800 of the fluidized bed 8 to the preheating oxidizer 7.

[0053] The inner component 10 with catalyst coating is composed of a connector. The outer wall is wrapped with metal fins, and the outer surface is loaded with a porous ceramic catalytic coating with cordierite micro powder as the skeleton and iron-praseodymium-gadolinium (Fe-Pr-Gd) composite oxide as the active component. The inner component 10 with catalyst coating is made of 2520 heat-resistant steel with a pipe diameter of 10mm. The fins are welded around the steel pipe, and the connector is 0.25m long.

[0054] The method for preparing the catalyst coating on the internal component 10 includes the following steps: (1) Praseodymium nitrate (Pr(NO3)3·6H2O), gadolinium nitrate (Gd(NO3)3·6H2O), and ferric nitrate (Fe(NO3)3·9H2O) were dissolved in deionized water at a molar ratio of Pr:Gd:Fe of 0.8:0.2:1.0. Citric acid was added as a complexing agent, with the molar ratio of citric acid to the total molar amount of metal cations (Pr ions, Gd ions, and Fe ions) being 1.2:1. The mixture was heated and stirred in an 80°C water bath for 1 hour to form a moderately viscous, uniform, transparent, reddish-brown metal complex sol.

[0055] (2) Add inorganic binder and aggregate to the sol obtained in step (1). The inorganic binder is an aluminum dihydrogen phosphate solution with a solid content of 50%, and the amount added is 50% of the dry weight of the sol. The aggregate is cordierite powder with an average particle size of 2 μm, and the mass ratio of the amount of cordierite powder added to the theoretically generated metal oxide in the sol is 1:1. Place the mixture in a ball mill jar and ball mill for 2 hours to prepare a thixotropic composite ceramic slurry with a solid content of about 50 wt%.

[0056] (3) The surface of the internal components made of 2520 heat-resistant steel is roughened by sandblasting (roughness Ra≈4μm), then cleaned with acetone by ultrasonic cleaning to remove oil, and dried at 100℃ for later use.

[0057] (4) Immerse the pretreated internal components vertically into the slurry of step (2) at a pulling speed of 8 mm / min to form a uniform wet film on the surface. Air dry at room temperature for 2 hours.

[0058] (5) After air-drying, the components are placed in a high-temperature furnace and calcined according to the following procedure: First stage (drying): Heat to 120℃ and keep at that temperature for 1 hour to remove free water; The second stage (self-propagating pore formation): The temperature is slowly increased to 350℃ at 1℃ / min and held for 1 hour. During this stage, citric acid and nitrate ions undergo an in-situ micro-combustion reaction, releasing gas and forming a sponge-like porous structure within the coating. The third stage (ceramization): The temperature is increased to 800℃ at 4℃ / min and held for 3 hours. During this stage, the aluminophosphate solidifies and crosslinks, and the Fe-Pr-Gd oxide crystallizes and anchors on the cordierite framework, ultimately forming a porous ceramic catalytic coating with a thickness of about 50μm, strong bonding, and chlorine resistance.

[0059] This embodiment uses the above-mentioned apparatus to remove organic matter from industrial sodium chloride waste salt through high-temperature oxidation. The total organic carbon content of the waste salt powder is 2250 mg TOC / kg. The specific steps include the following: S1: Open the valves on the air inlet pipe and natural gas inlet pipe of burner 9, and turn on the first air blower 3. Natural gas C and combustion air D enter burner 9 to ignite burner 9 and generate combustion gas. The combustion gas enters air heater 6 through combustion gas inlet 603. After the temperature inside air heater 6 reaches 150°C, turn on the second air blower 4. Process air B enters the heat exchange tube of air heater 6 from air filter 5 through the second air blower 4. The high-temperature combustion gas ejected from burner 9 in air heater 6 exchanges heat with the process air B entering from the air inlet. The heat exchange produces high-temperature process air B, which then enters the second layer at the bottom of fluidized bed 8 through the first valve 1001 and the side air inlet 808 to preheat fluidized bed 8 and preheat oxidizer 7. The combustion exhaust gas E after heat exchange is discharged from combustion exhaust gas E outlet 604. S2: When the gas temperature in the gas inlet pipe of the fourth-stage cyclone 704 of the preheating oxidizer 7 reaches 300℃, the screw feeder 2 is turned on, and the raw material waste salt powder A with an initial feed moisture content of 10% and a TOC concentration of 2250mgTOC / kg is added to the material inlet on the air inlet pipe of the first-stage cyclone 701 of the preheating oxidizer 7 through the material inlet; by adjusting the second air blower 4 and the first valve 1001, the flow rate of hot air entering the main bed layer of the fluidized bed 8 is controlled to ensure the air velocity requirements of the empty tower in the second and above layers of the fluidized bed 8 and the air velocity requirements in the gas inlet pipe of the fourth-stage cyclone 704; the waste salt powder enters from the gas inlet of the first-stage cyclone 701 and falls from the bottom outlet of the fourth-stage cyclone 704 into the top inlet of the fluidized bed 8; the waste salt powder entering the tower plate is in a fluidized state and flows from top to bottom between the sieve plates in the fluidized bed 8 through the powder overflow downcomer; S3: Open and adjust the third valve 1003, cold air enters the first layer at the bottom of the fluidized bed 8, maintaining the air velocity in the empty tower at 0.2m / s, fluidizing the hot salt in the first layer while cooling it down, reducing the temperature of the salt powder exiting the fluidized bed 8, and at the same time, the cold air is heated and enters the second layer at the bottom of the fluidized bed 8 to recover the heat of the hot salt. S4: Adjust the air flow rate and natural gas C flow rate entering the burner 9 to make the hot air outlet temperature of the burner 9 751℃ and the air pressure of the second air blower 4 12kPa; heat the process air B through the air heater 6 to raise the hot spot temperature of the fluidized bed 8 to 600℃ and the empty tower gas velocity to 0.3m / s; adjust the discharge rate of the screw feeder 2 to 19kg / min to make the fluidized bed 8 achieve stable operation, and the residence time of the waste salt powder in the fluidized bed 8 is 12min; on the multi-stage porous tower plates 804 of the fluidized bed 8, the high temperature air and sodium chloride salt are fully contacted in the fluidized state, so that most of the organic impurities in the sodium chloride salt react with oxygen at high temperature and are oxidized to meet the TOC requirements of the salt powder; process tail gas G is discharged from the top outlet of the first stage cyclone 701 of the preheating oxidizer 7; the salt product powder F cooled to about 141℃ is discharged through the discharge pipe 802; S5: When the temperature at the gas inlet pipe of the 4th stage cyclone 704 is less than 300℃, open and adjust the second valve 1002 to allow some high-temperature air to directly enter the gas inlet pipe of the 4th stage cyclone 704, and maintain the temperature of the gas inlet pipe of the 4th stage cyclone 704 at 300℃.

[0060] After the salt product powder F was naturally cooled, the total organic carbon content in the finished salt was measured to be 43.3 mg TOC / kg, which is equivalent to 13.0 mg / L of total organic carbon content in a 300 g / L sodium chloride solution used in ion-exchange membrane caustic soda production.

[0061] Example 2

[0062] The preheating oxidizer 7 is equipped with four cyclone separators connected in series; the fluidized bed 8 has a shell 800 with five layers and a diameter of 0.4m. Inside the shell 800, four layers of porous trays 804 are evenly distributed from top to bottom, with a distance of 1200mm between adjacent layers. The porosity of each layer of porous trays 804 is 1.5%. Powder overflow pipes 805 are installed on the porous trays 804. The ratio of the cylindrical cross-sectional area of ​​the powder overflow pipe 805 to the bed cross-sectional area is 0.04, and the ratio of the bottom constriction diameter to the upper pipe diameter is 0.5. The top of the cylindrical part of the powder overflow pipe 805 is 600mm from the porous tray 804 of the same layer, and the bottom of the constriction funnel of the powder overflow pipe 805 is 80mm from the lower porous tray 804. The distance between 4 is 300mm; the bottom shell 800 wall of the lowest porous tray 804 of the fluidized bed 8 is connected to the bottom air inlet 801, and a gas distribution plate 803 is provided in the shell 800 between the bottom air inlet 801 and the lowest porous tray 804 of the fluidized bed 8, with an opening ratio of 0.2%; the side air inlet 808 of the fluidized bed 8 is connected to the second layer of the fluidized bed 8, and an internal component 10 with a catalyst coating is provided between each layer of porous tray 804; a cyclone separator 806 is provided at the top of the fluidized bed 8, and the outlet pipe of the cyclone separator 806 is connected to the gas inlet at the bottom of the preheating oxidizer 7, for discharging the high-temperature air in the shell 800 of the fluidized bed 8 to the preheating oxidizer 7.

[0063] The inner component 10 with catalyst coating is composed of a connector. The outer wall is wrapped with metal fins, and the outer surface is loaded with a porous ceramic catalytic coating with cordierite micro powder as the skeleton and iron-praseodymium-gadolinium (Fe-Pr-Gd) composite oxide as the active component. The inner component 10 with catalyst coating is made of 2520 heat-resistant steel with a pipe diameter of 10mm. The fins are welded around the steel pipe, and the connector is 0.35m long.

[0064] The method for preparing the catalyst coating on the internal component 10 includes the following steps: (1) Praseodymium nitrate (Pr(NO3)3·6H2O), gadolinium nitrate (Gd(NO3)3·6H2O), and ferric nitrate (Fe(NO3)3·9H2O) were dissolved in deionized water at a molar ratio of Pr:Gd:Fe of 0.8:0.2:1.0. Citric acid was added as a complexing agent, with the molar ratio of citric acid to the total molar amount of metal cations (Pr ions, Gd ions, and Fe ions) being 1.2:1. The mixture was heated and stirred in an 80°C water bath for 1 hour to form a moderately viscous, uniform, transparent, reddish-brown metal complex sol.

[0065] (2) Add inorganic binder and aggregate to the sol obtained in step (1). The inorganic binder is an aluminum dihydrogen phosphate solution with a solid content of 50%, and the amount added is 50% of the dry weight of the sol. The aggregate is cordierite powder with an average particle size of 2 μm, and the mass ratio of the amount of cordierite powder added to the theoretically generated metal oxide in the sol is 1:1. Place the mixture in a ball mill jar and ball mill for 2 hours to prepare a thixotropic composite ceramic slurry with a solid content of about 50 wt%.

[0066] (3) The surface of the internal components made of 2520 heat-resistant steel is roughened by sandblasting (roughness Ra≈4μm), then cleaned with acetone by ultrasonic cleaning to remove oil, and dried at 100℃ for later use.

[0067] (4) Immerse the pretreated internal components vertically into the slurry of step (2) at a pulling speed of 8 mm / min to form a uniform wet film on the surface. Air dry at room temperature for 2 hours.

[0068] (5) Place the air-dried components in a high-temperature furnace and calcine them according to the following procedure: First stage (drying): Heat to 120℃ and keep at that temperature for 1 hour to remove free water; The second stage (self-propagating pore formation): The temperature is slowly increased to 350℃ at 1℃ / min and held for 1 hour. During this stage, citric acid and nitrate ions undergo an in-situ micro-combustion reaction, releasing gas and forming a sponge-like porous structure within the coating. The third stage (ceramization): The temperature is increased to 800℃ at 4℃ / min and held for 3 hours. During this stage, the aluminophosphate solidifies and crosslinks, and the Fe-Pr-Gd oxide crystallizes and anchors on the cordierite framework, ultimately forming a porous ceramic catalytic coating with a thickness of about 50μm, strong bonding, and chlorine resistance.

[0069] This embodiment uses the above-mentioned apparatus to remove organic matter from industrial sodium chloride waste salt through high-temperature oxidation. The total organic carbon content of the waste salt powder is 2550 mg TOC / kg. The specific steps include the following: S1: Open the valves on the air inlet pipe and natural gas inlet pipe of burner 9, and turn on the first air blower 3. Natural gas C and combustion air D enter burner 9 to ignite burner 9 and generate combustion gas. The combustion gas enters air heater 6 through combustion gas inlet 603. After the temperature inside air heater 6 reaches 150°C, turn on the second air blower 4. Process air B enters the heat exchange tube of air heater 6 from air filter 5 through the second air blower 4. The high-temperature combustion gas ejected from burner 9 in air heater 6 exchanges heat with the process air B entering from the air inlet. The heat exchange produces high-temperature process air B, which then enters the second layer at the bottom of fluidized bed 8 through the first valve 1001 and the side air inlet 808 to preheat fluidized bed 8 and preheat oxidizer 7. The combustion exhaust gas E after heat exchange is discharged from combustion exhaust gas E outlet 604. S2: When the gas temperature in the gas inlet pipe of the fourth-stage cyclone 704 of the preheating oxidizer 7 reaches 300℃, the screw feeder 2 is turned on, and the raw material waste salt powder A with an initial feed moisture content of 10% and a TOC concentration of 2550mgTOC / kg is added to the material inlet on the air inlet pipe of the first-stage cyclone 701 of the preheating oxidizer 7 through the material inlet; by adjusting the second air blower 4 and the first valve 1001, the flow rate of hot air entering the main bed layer of the fluidized bed 8 is controlled to ensure the empty tower gas velocity requirements in the second and above layers of the fluidized bed 8 and the gas velocity requirements in the gas inlet pipe of the fourth-stage cyclone 704; the waste salt powder enters from the gas inlet of the first-stage cyclone 701 and falls from the bottom outlet of the fourth-stage cyclone 704 into the top feed inlet of the fluidized bed 8; the waste salt powder entering the tower plate is in a fluidized state and flows from top to bottom between the sieve plates in the fluidized bed 8 through the powder overflow downcomer; S3: Open and adjust the third valve 1003, cold air enters the first layer at the bottom of the fluidized bed 8, maintaining the air velocity in the empty tower at 0.15m / s, fluidizing the hot salt in the first layer while cooling it down, reducing the temperature of the salt powder exiting the fluidized bed 8, and at the same time, the cold air is heated and enters the second layer at the bottom of the fluidized bed 8 to recover the heat of the hot salt. S4: Adjust the air flow rate and natural gas C flow rate entering the burner 9 to make the hot air outlet temperature of the burner 9 765℃ and the air pressure of the second air blower 4 15kPa; heat the process air B through the air heater 6 to make the hot spot temperature of the fluidized bed 8 591℃ and the empty tower gas velocity 0.3m / s; adjust the discharge rate of the screw feeder 2 to 39kg / min to make the fluidized bed 8 achieve stable operation, and the residence time of the waste salt powder in the fluidized bed 8 is 10min; on the multi-stage porous tower plates 804 of the fluidized bed 8, the high temperature air and sodium chloride salt are fully contacted in the fluidized state, so that most of the organic impurities in the sodium chloride salt react with oxygen at high temperature and are oxidized to meet the TOC requirements of the salt powder; process tail gas G is discharged from the top outlet of the first stage cyclone 701 of the preheating oxidizer 7; the salt product powder F cooled to about 150℃ is discharged through the discharge pipe 802; S5: When the temperature at the gas inlet pipe of the 4th stage cyclone 704 is less than 300℃, open and adjust the second valve 1002 to allow some high-temperature air to directly enter the gas inlet pipe of the 4th stage cyclone 704, and maintain the temperature of the gas inlet pipe of the 4th stage cyclone 704 at 300℃.

[0070] After the salt product powder F was naturally cooled, the total organic carbon content in the finished salt was measured to be 39.3 mgTOC / kg, which is equivalent to 11.8 mg / L of the total organic carbon content in a 300 g / L sodium chloride solution used in ion-exchange membrane caustic soda production.

[0071] Example 3

[0072] The preheating oxidizer 7 is equipped with 5 stages of cyclone separators connected in series; the fluidized bed 8 has a shell 800 with 6 layers and a diameter of 0.5m. Inside the shell 800, 5 layers of porous trays 804 are evenly distributed from top to bottom, with a distance of 1000mm between adjacent layers of porous trays 804. The opening ratio of each layer of porous trays 804 is 2.0%. Powder overflow pipes 805 are installed on the porous trays 804. The ratio of the cylindrical cross-sectional area of ​​the powder overflow pipe 805 to the cross-sectional area of ​​the bed is 0.05, and the ratio of the bottom constriction diameter to the upper pipe diameter is 0.5. The distance from the top of the cylindrical part of the powder overflow pipe 805 to the porous tray 804 of the same layer is 500mm, and the distance from the bottom of the constriction funnel of the powder overflow pipe 805 to the lower porous tray 804 is 800mm. The distance between 4 is 250mm; the bottom wall of the shell 800 below the bottom porous tray 804 of the fluidized bed 8 is connected to the bottom air inlet 801, and a gas distribution plate 803 is provided in the shell 800 between the bottom air inlet 801 and the bottom porous tray 804 of the fluidized bed 8, with an opening ratio of 1.0%; the side air inlet 808 of the fluidized bed 8 is connected to the second layer of the fluidized bed 8, and an internal component 10 with a catalyst coating is provided between each layer of porous tray 804; a cyclone separator 806 is provided at the top of the fluidized bed 8, and the outlet pipe of the cyclone separator 806 is connected to the gas inlet at the bottom of the preheating oxidizer 7, for discharging the high-temperature air in the shell 800 of the fluidized bed 8 to the preheating oxidizer 7.

[0073] The inner component 10 with catalyst coating is composed of two connectors. The outer wall is wrapped with metal fins, and the outer surface is loaded with a porous ceramic catalytic coating with cordierite micro powder as the skeleton and iron-praseodymium-gadolinium (Fe-Pr-Gd) composite oxide as the active component. The inner component 10 with catalyst coating is made of 2520 heat-resistant steel with a pipe diameter of 20mm. The fins are welded around the steel pipe, and the connector is 0.45m long.

[0074] The method for preparing the catalyst coating on the internal component 10 includes the following steps: (1) Praseodymium nitrate (Pr(NO3)3·6H2O), gadolinium nitrate (Gd(NO3)3·6H2O), and ferric nitrate (Fe(NO3)3·9H2O) were dissolved in deionized water at a molar ratio of Pr:Gd:Fe of 0.8:0.2:1.0. Citric acid was added as a complexing agent, with the molar ratio of citric acid to the total molar amount of metal cations (Pr ions, Gd ions, and Fe ions) being 1.2:1. The mixture was heated and stirred in an 80°C water bath for 1 hour to form a moderately viscous, uniform, transparent, reddish-brown metal complex sol.

[0075] (2) Add inorganic binder and aggregate to the sol obtained in step (1). The inorganic binder is an aluminum dihydrogen phosphate solution with a solid content of 50%, and the amount added is 60% of the dry weight of the sol. The aggregate is cordierite powder with an average particle size of 3 μm, and the mass ratio of the amount of cordierite powder added to the theoretically generated metal oxide in the sol is 1:1. Place the mixture in a ball mill jar and ball mill for 2 hours to prepare a thixotropic composite ceramic slurry with a solid content of about 50 wt%.

[0076] (3) The surface of the internal components made of 2520 heat-resistant steel is roughened by sandblasting (roughness Ra≈4μm), then cleaned with acetone by ultrasonic cleaning to remove oil, and dried at 100℃ for later use.

[0077] (4) Immerse the pretreated internal components vertically into the slurry of step (2) at a pulling speed of 6 mm / min to form a uniform wet film on the surface. Air dry at room temperature for 2 hours.

[0078] (5) Place the air-dried components in a high-temperature furnace and calcine them according to the following procedure: First stage (drying): Heat to 130℃ and keep at that temperature for 2 hours to remove free water; The second stage (self-propagating pore formation): The temperature is slowly increased to 350℃ at 1℃ / min and held for 1 hour. During this stage, citric acid and nitrate ions undergo an in-situ micro-combustion reaction, releasing gas and forming a sponge-like porous structure within the coating. The third stage (ceramization): The temperature is increased to 800℃ at 4℃ / min and held for 3 hours. During this stage, the aluminophosphate solidifies and crosslinks, and the Fe-Pr-Gd oxide crystallizes and anchors on the cordierite framework, ultimately forming a porous ceramic catalytic coating with a thickness of about 63μm, strong bonding, and chlorine resistance.

[0079] This embodiment uses the above-mentioned apparatus to remove organic matter from industrial sodium chloride waste salt through high-temperature oxidation. The total organic carbon content of the waste salt powder is 2731 mg TOC / kg. The specific steps include the following: S1: Open the valves on the air inlet pipe and natural gas inlet pipe of burner 9, and turn on the first air blower 3. Natural gas C and combustion air D enter burner 9 to ignite burner 9 and generate combustion gas. The combustion gas enters air heater 6 through combustion gas inlet 603. After the temperature inside air heater 6 reaches 150°C, turn on the second air blower 4. Process air B enters the heat exchange tube of air heater 6 from air filter 5 through the second air blower 4. The high-temperature combustion gas ejected from burner 9 in air heater 6 exchanges heat with the process air B entering from the air inlet. The heat exchange produces high-temperature process air B, which then enters the second layer at the bottom of fluidized bed 8 through the first valve 1001 and the side air inlet 808 to preheat fluidized bed 8 and preheat oxidizer 7. The combustion exhaust gas E after heat exchange is discharged from combustion exhaust gas E outlet 604. S2: When the gas temperature in the gas inlet pipe of the fifth-stage cyclone in the preheating oxidizer 7 reaches 300℃, the screw feeder 2 is turned on, and the raw material waste salt powder A with an initial feed moisture content of 10% and a TOC concentration of 2731mgTOC / kg is added to the material inlet on the air inlet pipe of the first-stage cyclone 701 of the preheating oxidizer 7 through the material inlet; by adjusting the second air blower 4 and the first valve 1001, the flow rate of hot air entering the main bed layer of the fluidized bed 8 is controlled to ensure the air velocity requirements of the empty tower in the second and above layers of the fluidized bed 8 and the air velocity requirements in the gas inlet pipe of the fifth-stage cyclone; the waste salt powder enters from the gas inlet of the first-stage cyclone 701 and falls from the bottom outlet of the fifth-stage cyclone into the top inlet of the fluidized bed 8; the waste salt powder entering the tower plate is in a fluidized state and flows from top to bottom between the sieve plates in the fluidized bed 8 through the powder overflow downcomer; S3: Open and adjust the third valve 1003, cold air enters the first layer at the bottom of the fluidized bed 8, maintaining the air velocity in the empty tower at 0.13m / s, fluidizing the hot salt in the first layer while cooling it down, reducing the temperature of the salt powder exiting the fluidized bed 8, and at the same time, the cold air is heated and enters the second layer at the bottom of the fluidized bed 8 to recover the heat of the hot salt. S4: Adjust the air flow rate and natural gas C flow rate entering the burner 9 to make the hot air outlet temperature of the burner 9 780℃ and the air pressure of the second air blower 4 18kPa; heat the process air B through the air heater 6 to make the hot spot temperature of the fluidized bed 8 580℃ and the empty tower gas velocity 0.4m / s; adjust the discharge rate of the screw feeder 2 to 65kg / min to make the fluidized bed 8 achieve stable operation, and the residence time of the waste salt powder in the fluidized bed 8 is 9min; on the porous tower plates 804 of each stage of the fluidized bed 8, the high temperature air and sodium chloride salt are fully contacted in the fluidized state, so that most of the organic impurities in the sodium chloride salt react with oxygen at high temperature and are oxidized to meet the TOC requirements of the salt powder; process tail gas G is discharged from the top outlet of the first stage cyclone 701 of the preheating oxidizer 7; the salt product powder F cooled to about 156℃ is discharged through the discharge pipe 802; S5: When the temperature at the gas inlet pipe of the 5th stage cyclone is less than 300℃, open and adjust the second valve 1002 to allow some high-temperature air to directly enter the gas inlet pipe of the 5th stage cyclone and maintain the temperature of the gas inlet pipe of the 5th stage cyclone at 300℃.

[0080] After the salt product powder F was naturally cooled, the total organic carbon content in the finished salt was measured to be 26.7 mg TOC / kg, which is equivalent to 8.0 mg / L of total organic carbon content in a 300 g / L sodium chloride solution used in ion-exchange membrane caustic soda production.

[0081] Example 4

[0082] The preheating oxidizer 7 is equipped with 8 stages of cyclone separators connected in series; the fluidized bed 8 has a shell 800 with 7 layers and a diameter of 0.6m. Inside the shell 800, 6 layers of porous trays 804 are evenly distributed from top to bottom, with a distance of 800mm between adjacent layers of porous trays 804. The opening ratio of each layer of porous trays 804 is 1.5%. Powder overflow pipes 805 are installed on the porous trays 804. The ratio of the cylindrical cross-sectional area of ​​the powder overflow pipe 805 to the cross-sectional area of ​​the bed is 0.06, and the ratio of the bottom constriction diameter to the upper pipe diameter is 0.5. The top of the cylindrical part of the powder overflow pipe 805 is 400mm from the porous tray 804 of the same layer, and the bottom of the constriction funnel of the powder overflow pipe 805 is 80mm from the lower porous tray. The distance between 4 is 200mm; the bottom shell 800 wall of the lowest porous tray 804 of the fluidized bed 8 is connected to the bottom air inlet 801, and a gas distribution plate 803 is provided in the shell 800 between the bottom air inlet 801 and the lowest porous tray 804 of the fluidized bed 8, with an opening ratio of 1.0%; the side air inlet 808 of the fluidized bed 8 is connected to the second layer of the fluidized bed 8, and an internal component 10 with a catalyst coating is provided between each porous tray 804; a cyclone separator 806 is provided at the top of the fluidized bed 8, and the outlet pipe of the cyclone separator 806 is connected to the gas inlet at the bottom of the preheating oxidizer 7, for discharging the high-temperature air in the shell 800 of the fluidized bed 8 to the preheating oxidizer 7.

[0083] The inner component 10 with catalyst coating is composed of 4 connectors. The outer wall is wrapped with metal fins, and the outer surface is loaded with a porous ceramic catalytic coating with cordierite micro powder as the skeleton and iron-praseodymium-gadolinium (Fe-Pr-Gd) composite oxide as the active component. The inner component 10 with catalyst coating is made of 2520 heat-resistant steel with a pipe diameter of 20mm. The fins are welded around the steel pipe, and the length of the connector is 0.55m.

[0084] The method for preparing the catalyst coating on the internal component 10 includes the following steps: (1) Praseodymium nitrate (Pr(NO3)3·6H2O), gadolinium nitrate (Gd(NO3)3·6H2O), and ferric nitrate (Fe(NO3)3·9H2O) were dissolved in deionized water at a molar ratio of Pr:Gd:Fe of 0.8:0.2:1.0. Citric acid was added as a complexing agent, with the molar ratio of citric acid to the total molar amount of metal cations (Pr ions, Gd ions, and Fe ions) being 1.2:1. The mixture was heated and stirred in an 80°C water bath for 1 hour to form a moderately viscous, uniform, transparent, reddish-brown metal complex sol.

[0085] (2) Add inorganic binder and aggregate to the sol obtained in step (1). The inorganic binder is an aluminum dihydrogen phosphate solution with a solid content of 50%, and the amount added is 60% of the dry weight of the sol. The aggregate is cordierite powder with an average particle size of 3 μm, and the mass ratio of the amount of cordierite powder added to the theoretically generated metal oxide in the sol is 1:1. Place the mixture in a ball mill jar and ball mill for 2 hours to prepare a thixotropic composite ceramic slurry with a solid content of about 50 wt%.

[0086] (3) The surface of the internal components made of 2520 heat-resistant steel is roughened by sandblasting (roughness Ra≈4μm), then cleaned with acetone by ultrasonic cleaning to remove oil, and dried at 100℃ for later use.

[0087] (4) Immerse the pretreated internal components vertically into the slurry of step (2) at a pulling speed of 6 mm / min to form a uniform wet film on the surface. Air dry at room temperature for 2 hours.

[0088] (5) Place the air-dried components in a high-temperature furnace and calcine them according to the following procedure: First stage (drying): Heat to 150℃ and keep at that temperature for 2 hours to remove free water; The second stage (self-propagating pore formation): The temperature is slowly increased to 400℃ at 2℃ / min and held for 2 hours. During this stage, citric acid and nitrate ions undergo an in-situ micro-combustion reaction, releasing gas and forming a sponge-like porous structure within the coating. The third stage (ceramization): The temperature is increased to 900℃ at 4℃ / min and held for 4 hours. During this stage, the aluminophosphate solidifies and crosslinks, and the Fe-Pr-Gd oxide crystallizes and anchors on the cordierite framework, ultimately forming a porous ceramic catalytic coating with a thickness of about 68μm, strong bonding, and chlorine resistance.

[0089] This embodiment uses the above-mentioned apparatus to remove organic matter from industrial sodium chloride waste salt through high-temperature oxidation. The total organic carbon content of the waste salt powder is 3006 mg TOC / kg. The specific steps include the following: S1: Open the valves on the air inlet pipe and natural gas inlet pipe of burner 9, and turn on the first air blower 3. Natural gas C and combustion air D enter burner 9 to ignite burner 9 and generate combustion gas. The combustion gas enters air heater 6 through combustion gas inlet 603. After the temperature inside air heater 6 reaches 150°C, turn on the second air blower 4. Process air B enters the heat exchange tube of air heater 6 from air filter 5 through the second air blower 4. The high-temperature combustion gas ejected from burner 9 in air heater 6 exchanges heat with the process air B entering from the air inlet. The heat exchange produces high-temperature process air B, which then enters the second layer at the bottom of fluidized bed 8 through the first valve 1001 and the side air inlet 808 to preheat fluidized bed 8 and preheat oxidizer 7. The combustion exhaust gas E after heat exchange is discharged from combustion exhaust gas E outlet 604. S2: When the gas temperature in the gas inlet pipe of the 8th stage cyclone of the preheating oxidizer 7 reaches 300℃, turn on the screw feeder 2 and add the raw material waste salt powder A with an initial feed moisture content of 10% and a TOC concentration of 3006mgTOC / kg to the material inlet of the air inlet pipe of the 1st stage cyclone 701 of the preheating oxidizer 7 through the material inlet; by adjusting the second air blower 4 and the first valve 1001, regulate the flow rate of hot air entering the main bed layer of the fluidized bed 8 to ensure the air velocity requirements of the empty tower in the second and above layers of the fluidized bed 8 and the air velocity requirements in the gas inlet pipe of the 8th stage cyclone; the waste salt powder enters from the gas inlet of the 1st stage cyclone 701 and falls from the bottom outlet of the 8th stage cyclone into the top inlet of the fluidized bed 8; the waste salt powder entering the tower plate is in a fluidized state and flows from top to bottom between the screen plates in the fluidized bed 8 through the powder overflow downcomer; S3: Open and adjust the third valve 1003, cold air enters the first layer at the bottom of the fluidized bed 8, maintaining the air velocity in the empty tower at 0.16m / s, fluidizing the hot salt in the first layer while cooling it down, reducing the temperature of the salt powder exiting the fluidized bed 8, and at the same time, the cold air is heated and enters the second layer at the bottom of the fluidized bed 8 to recover the heat from the hot salt. S4: Adjust the air flow rate and natural gas C flow rate entering the burner 9 to make the hot air outlet temperature of the burner 9 800℃ and the air pressure of the second air blower 4 22kPa; heat the process air B through the air heater 6 to make the hot spot temperature of the fluidized bed 8 585℃ and the empty tower gas velocity 0.5m / s; adjust the discharge rate of the screw feeder 2 to 98kg / min to make the fluidized bed 8 achieve stable operation, and the residence time of the waste salt powder in the fluidized bed 8 is 8min; on the porous tower plates 804 of each stage of the fluidized bed 8, the high temperature air and sodium chloride salt are fully contacted in the fluidized state, so that most of the organic impurities in the sodium chloride salt react with oxygen at high temperature and are oxidized to meet the TOC requirements of the salt powder; process tail gas G is discharged from the top outlet of the first stage cyclone 701 of the preheating oxidizer 7; the salt product powder F cooled to about 138℃ is discharged through the discharge pipe 802; S5: When the temperature at the gas inlet pipe of the 8th stage cyclone is less than 300℃, open and adjust the second valve 1002 to allow some high-temperature air to directly enter the gas inlet pipe of the 8th stage cyclone and maintain the temperature of the gas inlet pipe of the 8th stage cyclone at 300℃.

[0090] After the salt product powder F was naturally cooled, the total organic carbon content in the finished salt was measured to be 30.0 mg TOC / kg, which is equivalent to 9.0 mg / L of the total organic carbon content in a 300 g / L sodium chloride solution used in ion-exchange membrane caustic soda production.

[0091] Example 5

[0092] The preheating oxidizer 7 is equipped with 5 stages of cyclone separators connected in series; the fluidized bed 8 has a shell 800 with 8 layers and a diameter of 0.7m. Inside the shell 800, 7 layers of porous trays 804 are evenly distributed from top to bottom, with a distance of 600mm between adjacent layers of porous trays 804. The opening ratio of each layer of porous trays 804 is 3.0%. Powder overflow pipes 805 are installed on the porous trays 804. The ratio of the cylindrical cross-sectional area of ​​the powder overflow pipe 805 to the cross-sectional area of ​​the bed is 0.07, and the ratio of the bottom constriction diameter to the upper pipe diameter is 0.6. The top of the cylindrical part of the powder overflow pipe 805 is 300mm from the porous tray 804 of the same layer, and the bottom of the constriction funnel of the powder overflow pipe 805 is 80mm from the lower porous tray 804. The distance between 4 is 150mm; the bottom shell 800 wall of the lowest porous tray 804 of the fluidized bed 8 is connected to the bottom air inlet 801, and a gas distribution plate 803 is provided in the shell 800 between the bottom air inlet 801 and the lowest porous tray 804 of the fluidized bed 8, with an opening ratio of 1.0%; the side air inlet 808 of the fluidized bed 8 is connected to the second layer of the fluidized bed 8, and an internal component 10 with a catalyst coating is provided between each porous tray 804; a cyclone separator 806 is provided at the top of the fluidized bed 8, and the outlet pipe of the cyclone separator 806 is connected to the gas inlet at the bottom of the preheating oxidizer 7, for discharging the high-temperature air in the shell 800 of the fluidized bed 8 to the preheating oxidizer 7.

[0093] The inner component 10 with catalyst coating is composed of 5 connectors. The outer wall is wrapped with metal fins, and the outer surface is loaded with a porous ceramic catalytic coating with cordierite micro powder as the skeleton and iron-praseodymium-gadolinium (Fe-Pr-Gd) composite oxide as the active component. The inner component 10 with catalyst coating is made of 2520 heat-resistant steel with a pipe diameter of 30mm. The fins are welded around the steel pipe, and the connector length is 0.6m.

[0094] The method for preparing the catalyst coating on the internal component 10 includes the following steps: (1) Praseodymium nitrate (Pr(NO3)3·6H2O), gadolinium nitrate (Gd(NO3)3·6H2O), and ferric nitrate (Fe(NO3)3·9H2O) were dissolved in deionized water at a molar ratio of Pr:Gd:Fe of 0.8:0.2:1.0. Citric acid was added as a complexing agent, with the molar ratio of citric acid to the total molar amount of metal cations (Pr ions, Gd ions, and Fe ions) being 1.2:1. The mixture was heated and stirred in an 80°C water bath for 1 hour to form a moderately viscous, uniform, transparent, reddish-brown metal complex sol.

[0095] (2) Add inorganic binder and aggregate to the sol obtained in step (1). The inorganic binder is an aluminum dihydrogen phosphate solution with a solid content of 50%, and the amount added is 40% of the dry weight of the sol. The aggregate is cordierite powder with an average particle size of 5 μm, and the mass ratio of the amount of cordierite powder added to the theoretically generated metal oxide in the sol is 1:1. Place the mixture in a ball mill jar and ball mill for 2 hours to prepare a thixotropic composite ceramic slurry with a solid content of about 50 wt%.

[0096] (3) The surface of the internal components made of 2520 heat-resistant steel is roughened by sandblasting (roughness Ra≈4μm), then cleaned with acetone by ultrasonic cleaning to remove oil, and dried at 100℃ for later use.

[0097] (4) Immerse the pretreated internal components vertically into the slurry of step (2) at a pulling speed of 6 mm / min to form a uniform wet film on the surface. Air dry at room temperature for 2 hours.

[0098] (5) Place the air-dried components in a high-temperature furnace and calcine them according to the following procedure: First stage (drying): Heat to 150℃ and keep at that temperature for 3 hours to remove free water; The second stage (self-propagating pore formation): The temperature is slowly increased to 400℃ at 2℃ / min and held for 2 hours. During this stage, citric acid and nitrate ions undergo an in-situ micro-combustion reaction, releasing gas and forming a sponge-like porous structure within the coating. The third stage (ceramization): The temperature is increased to 900℃ at 4℃ / min and held for 4 hours. During this stage, the aluminophosphate solidifies and crosslinks, and the Fe-Pr-Gd oxide crystallizes and anchors on the cordierite framework, ultimately forming a porous ceramic catalytic coating with a thickness of about 82μm, strong bonding, and chlorine resistance.

[0099] This embodiment uses the above-mentioned apparatus to remove organic matter from industrial sodium chloride waste salt through high-temperature oxidation. The total organic carbon content of the waste salt powder is 2834 mg TOC / kg. The specific steps include the following: S1: Open the valves on the air inlet pipe and natural gas inlet pipe of burner 9, and turn on the first air blower 3. Natural gas C and combustion air D enter burner 9 to ignite burner 9 and generate combustion gas. The combustion gas enters air heater 6 through combustion gas inlet 603. After the temperature inside air heater 6 reaches 150°C, turn on the second air blower 4. Process air B enters the heat exchange tube of air heater 6 from air filter 5 through the second air blower 4. The high-temperature combustion gas ejected from burner 9 in air heater 6 exchanges heat with the process air B entering from the air inlet. The heat exchange produces high-temperature process air B, which then enters the second layer at the bottom of fluidized bed 8 through the first valve 1001 and the side air inlet 808 to preheat fluidized bed 8 and preheat oxidizer 7. The combustion exhaust gas E after heat exchange is discharged from combustion exhaust gas E outlet 604. S2: When the gas temperature in the gas inlet pipe of the fifth-stage cyclone in the preheating oxidizer 7 reaches 300℃, the screw feeder 2 is turned on, and the raw material waste salt powder A with an initial feed moisture content of 8.0% and a TOC concentration of 2834mgTOC / kg is added to the material inlet of the first-stage cyclone 701 in the preheating oxidizer 7 through the material inlet; by adjusting the second air blower 4 and the first valve 1001, the flow rate of hot air entering the main bed layer of the fluidized bed 8 is controlled to ensure the empty tower gas velocity requirements in the second and above layers of the fluidized bed 8 and the gas velocity requirements in the gas inlet pipe of the fifth-stage cyclone; the waste salt powder enters from the gas inlet of the first-stage cyclone 701 and falls from the bottom outlet of the fifth-stage cyclone into the top feed inlet of the fluidized bed 8; the waste salt powder entering the tower plate is in a fluidized state and flows from top to bottom between the sieve plates in the fluidized bed 8 through the powder overflow downcomer; S3: Open and adjust the third valve 1003, cold air enters the first layer at the bottom of the fluidized bed 8, maintaining the air velocity in the empty tower at 0.18 m / s, fluidizing the hot salt in the first layer while cooling it down, reducing the temperature of the salt powder exiting the fluidized bed 8, and at the same time, the cold air is heated and enters the second layer at the bottom of the fluidized bed 8 to recover the heat of the hot salt. S4: Adjust the air flow rate and natural gas C flow rate entering the burner 9 to make the hot air outlet temperature of the burner 9 820℃ and the air pressure of the second air blower 4 28kPa; heat the process air B through the air heater 6 to make the hot spot temperature of the fluidized bed 8 580℃ and the empty tower gas velocity 0.6m / s; adjust the discharge rate of the screw feeder 2 to reach 150kg / min to make the fluidized bed 8 achieve stable operation, and the residence time of the waste salt powder in the fluidized bed 8 is 6min; on the multi-stage porous tower plates 804 of the fluidized bed 8, the high temperature air and sodium chloride salt are fully contacted in the fluidized state, so that most of the organic impurities in the sodium chloride salt react with oxygen at high temperature and are oxidized to meet the TOC requirements of the salt powder; process tail gas G is discharged from the top outlet of the first stage cyclone 701 of the preheating oxidizer 7; the salt product powder F cooled to about 138℃ is discharged through the discharge pipe 802; S5: When the temperature at the gas inlet pipe of the 5th stage cyclone is less than 300℃, open and adjust the second valve 1002 to allow some high-temperature air to directly enter the gas inlet pipe of the 5th stage cyclone and maintain the temperature of the gas inlet pipe of the 5th stage cyclone at 300℃.

[0100] After the salt product powder F was naturally cooled, the total organic carbon content in the finished salt was measured to be 23.7 mg TOC / kg, which is equivalent to 7.1 mg / L of the total organic carbon content in a 300 g / L sodium chloride solution used in ion-exchange membrane caustic soda production.

[0101] Example 6

[0102] The preheating oxidizer 7 is equipped with 8 stages of cyclone separators connected in series; the fluidized bed 8 has a shell 800 with 8 layers and a diameter of 0.7m. Inside the shell 800, 7 layers of porous trays 804 are evenly distributed from top to bottom, with a distance of 500mm between adjacent layers of porous trays 804. The porosity of each layer of porous trays 804 is 4.0%. Powder overflow pipes 805 are installed on the porous trays 804. The ratio of the cylindrical cross-sectional area of ​​the powder overflow pipe 805 to the cross-sectional area of ​​the bed is 0.08, and the ratio of the bottom constriction diameter to the upper pipe diameter is 0.6. The top of the cylindrical part of the powder overflow pipe 805 is 250mm from the porous tray 804 of the same layer, and the bottom of the constriction funnel of the powder overflow pipe 805 is 80mm from the lower porous tray 804. The distance between 4 is 125mm; the bottom shell 800 wall of the lowest porous tray 804 of the fluidized bed 8 is connected to the bottom air inlet 801, and a gas distribution plate 803 is provided in the shell 800 between the bottom air inlet 801 and the lowest porous tray 804 of the fluidized bed 8, with an opening ratio of 1.0%; the side air inlet 808 of the fluidized bed 8 is connected to the second layer of the fluidized bed 8, and an internal component 10 with a catalyst coating is provided between each layer of porous tray 804; a cyclone separator 806 is provided at the top of the fluidized bed 8, and the outlet pipe of the cyclone separator 806 is connected to the gas inlet at the bottom of the preheating oxidizer 7, for discharging the high-temperature air in the shell 800 of the fluidized bed 8 to the preheating oxidizer 7.

[0103] The inner component 10 with catalyst coating is composed of 5 connectors. The outer wall is wrapped with metal fins, and the outer surface is loaded with a porous ceramic catalytic coating with cordierite micro powder as the skeleton and iron-praseodymium-gadolinium (Fe-Pr-Gd) composite oxide as the active component. The inner component 10 with catalyst coating is made of 2520 heat-resistant steel with a pipe diameter of 30mm. The fins are welded around the steel pipe, and the connector length is 0.6m.

[0104] The method for preparing the catalyst coating on the internal component 10 includes the following steps: (1) Praseodymium nitrate (Pr(NO3)3·6H2O), gadolinium nitrate (Gd(NO3)3·6H2O), and ferric nitrate (Fe(NO3)3·9H2O) were dissolved in deionized water at a molar ratio of Pr:Gd:Fe of 0.8:0.2:1.0. Citric acid was added as a complexing agent, with the molar ratio of citric acid to the total molar amount of metal cations (Pr ions, Gd ions, and Fe ions) being 1.2:1. The mixture was heated and stirred in an 80°C water bath for 1 hour to form a moderately viscous, uniform, transparent, reddish-brown metal complex sol.

[0105] (2) Add inorganic binder and aggregate to the sol obtained in step (1). The inorganic binder is an aluminum dihydrogen phosphate solution with a solid content of 50%, and the amount added is 40% of the dry weight of the sol. The aggregate is cordierite powder with an average particle size of 5 μm, and the mass ratio of the amount of cordierite powder added to the theoretically generated metal oxide in the sol is 1:1. Place the mixture in a ball mill jar and ball mill for 2 hours to prepare a thixotropic composite ceramic slurry with a solid content of about 50 wt%.

[0106] (3) The surface of the internal components made of 2520 heat-resistant steel is roughened by sandblasting (roughness Ra≈4μm), then cleaned with acetone by ultrasonic cleaning to remove oil, and dried at 100℃ for later use.

[0107] (4) Immerse the pretreated internal components vertically into the slurry of step (2) at a pulling speed of 6 mm / min to form a uniform wet film on the surface. Air dry at room temperature for 2 hours.

[0108] (5) Place the air-dried components in a high-temperature furnace and calcine them according to the following procedure: First stage (drying): Heat to 150℃ and keep at that temperature for 3 hours to remove free water; The second stage (self-propagating pore formation): The temperature is slowly increased to 400℃ at 2℃ / min and held for 2 hours. During this stage, citric acid and nitrate ions undergo an in-situ micro-combustion reaction, releasing gas and forming a sponge-like porous structure within the coating. The third stage (ceramization): The temperature is increased to 900℃ at 4℃ / min and held for 4 hours. During this stage, the aluminophosphate solidifies and crosslinks, and the Fe-Pr-Gd oxide crystallizes and anchors on the cordierite framework, ultimately forming a porous ceramic catalytic coating with a thickness of about 82μm, strong bonding, and chlorine resistance.

[0109] This embodiment uses the above-mentioned apparatus to remove organic matter from industrial sodium chloride waste salt through high-temperature oxidation. The total organic carbon content of the waste salt powder is 3122 mg TOC / kg. The specific steps include the following: S1: Open the valves on the air inlet pipe and natural gas inlet pipe of burner 9, and turn on the first air blower 3. Natural gas C and combustion air D enter burner 9 to ignite burner 9 and generate combustion gas. The combustion gas enters air heater 6 through combustion gas inlet 603. After the temperature inside air heater 6 reaches 150°C, turn on the second air blower 4. Process air B enters the heat exchange tube of air heater 6 from air filter 5 through the second air blower 4. The high-temperature combustion gas ejected from burner 9 in air heater 6 exchanges heat with the process air B entering from the air inlet. The heat exchange produces high-temperature process air B, which then enters the second layer at the bottom of fluidized bed 8 through the first valve 1001 and the side air inlet 808 to preheat fluidized bed 8 and preheat oxidizer 7. The combustion exhaust gas E after heat exchange is discharged from combustion exhaust gas E outlet 604. S2: When the gas temperature in the gas inlet pipe of the 8th stage cyclone of the preheating oxidizer 7 reaches 300℃, the screw feeder 2 is turned on, and the raw material waste salt powder A with an initial feed moisture content of 9.2% and a TOC concentration of 3122mgTOC / kg is added to the material inlet on the air inlet pipe of the 2nd stage cyclone 702 of the preheating oxidizer 7 through the material inlet; by adjusting the second air blower 4 and the first valve 1001, the flow rate of hot air entering the main bed layer of the fluidized bed 8 is controlled to ensure the air velocity requirements of the empty tower in the second layer and above of the fluidized bed 8 and the air velocity requirements in the gas inlet pipe of the 8th stage cyclone; the waste salt powder enters from the gas inlet of the 1st stage cyclone 701 and falls from the bottom outlet of the 8th stage cyclone into the top inlet of the fluidized bed 8; the waste salt powder entering the tower plate is in a fluidized state and flows from top to bottom between the screen plates in the fluidized bed 8 through the powder overflow downcomer; S3: Open and adjust the third valve 1003, cold air enters the first layer at the bottom of the fluidized bed 8, maintaining the air velocity in the empty tower at 0.18 m / s, fluidizing the hot salt in the first layer while cooling it down, reducing the temperature of the salt powder exiting the fluidized bed 8, and at the same time, the cold air is heated and enters the second layer at the bottom of the fluidized bed 8 to recover the heat of the hot salt. S4: Adjust the air flow rate and natural gas C flow rate entering the burner 9 to make the hot air outlet temperature of the burner 9 840℃ and the air pressure of the second air blower 4 32kPa; heat the process air B through the air heater 6 to make the hot spot temperature of the fluidized bed 8 585℃ and the empty tower gas velocity 0.8m / s; adjust the discharge rate of the screw feeder 2 to reach 210kg / min to make the fluidized bed 8 achieve stable operation, and the residence time of the waste salt powder in the fluidized bed 8 is 4min; on the multi-stage porous tower plates 804 of the fluidized bed 8, the high temperature air and sodium chloride salt are fully contacted in the fluidized state, so that most of the organic impurities in the sodium chloride salt react with oxygen at high temperature and are oxidized to meet the TOC requirements of the salt powder; process tail gas G is discharged from the top outlet of the first stage cyclone 701 of the preheating oxidizer 7; the salt product powder F cooled to about 148℃ is discharged through the discharge pipe 802; S5: When the temperature at the gas inlet pipe of the 8th stage cyclone is less than 300℃, open and adjust the second valve 1002 to allow some high-temperature air to directly enter the gas inlet pipe of the 8th stage cyclone and maintain the temperature of the gas inlet pipe of the 8th stage cyclone at 300℃.

[0110] After the salt product powder F was naturally cooled, the total organic carbon content in the finished salt was measured to be 28.5 mg TOC / kg, which is equivalent to 8.6 mg / L of the total organic carbon content in a 300 g / L sodium chloride solution used in ion-exchange membrane caustic soda production.

[0111] Comparative Example 1

[0112] This comparative example uses the aforementioned device with the internal component 10 with the catalyst coating removed. The preheating oxidizer 7 is equipped with four cyclone separators connected in series. The fluidized bed 8 has a shell 800 with four layers and a diameter of 0.3 m. Inside the shell 800, three layers of porous trays 804 are evenly distributed from top to bottom, with a distance of 1800 mm between adjacent layers of porous trays 804. The porosity of each layer of porous trays 804 is 0.5%. A powder overflow pipe 805 is installed on the porous trays 804. The ratio of the cross-sectional area of ​​the cylindrical part of the powder overflow pipe 805 to the cross-sectional area of ​​the bed is 0.03, and the ratio of the bottom diameter to the upper diameter is 0.5. The distance from the top of the cylindrical part of the powder overflow pipe 805 to the porous tray 804 of the same layer is 800 mm. The bottom end of the hopper of the powder overflow pipe 805 is 400 mm away from the lower porous tray 804; the shell 800 wall below the lowest porous tray 804 of the fluidized bed 8 is connected to a bottom air inlet 801, and a gas distribution plate 803 is provided in the shell 800 between the bottom air inlet 801 and the lowest porous tray 804 of the fluidized bed 8, with an opening ratio of 0.2%; the side air inlet 808 of the fluidized bed 8 is connected to the second layer of the fluidized bed 8; a cyclone separator 806 is provided at the top of the fluidized bed 8, and the outlet pipe of the cyclone separator 806 is connected to the gas inlet at the bottom of the preheating oxidizer 7, for discharging the high-temperature air in the shell 800 of the fluidized bed 8 to the preheating oxidizer 7.

[0113] This comparative example uses the aforementioned apparatus with the catalyst-coated internal component 10 removed to remove organic matter from industrial sodium chloride waste salt through high-temperature oxidation. The total organic carbon content of the waste salt powder is 2250 mg TOC / kg. The specific steps include the following: S1: Open the valves on the air inlet pipe and natural gas inlet pipe of burner 9, and turn on the first air blower 3. Natural gas C and combustion air D enter burner 9 to ignite burner 9 and generate combustion gas. The combustion gas enters air heater 6 through combustion gas inlet 603. After the temperature inside air heater 6 reaches 150°C, turn on the second air blower 4. Process air B enters the heat exchange tube of air heater 6 from air filter 5 through the second air blower 4. The high-temperature combustion gas ejected from burner 9 in air heater 6 exchanges heat with the process air B entering from the air inlet. The heat exchange produces high-temperature process air B, which then enters the second layer at the bottom of fluidized bed 8 through the first valve 1001 and the side air inlet 808 to preheat fluidized bed 8 and preheat oxidizer 7. The combustion exhaust gas E after heat exchange is discharged from combustion exhaust gas E outlet 604. S2: When the gas temperature in the gas inlet pipe of the fourth-stage cyclone 704 of the preheating oxidizer 7 reaches 300℃, the screw feeder 2 is turned on, and the raw material waste salt powder A with an initial feed moisture content of 10% and a TOC concentration of 2250mgTOC / kg is added to the material inlet on the air inlet pipe of the first-stage cyclone 701 of the preheating oxidizer 7 through the material inlet; by adjusting the second air blower 4 and the first valve 1001, the flow rate of hot air entering the main bed layer of the fluidized bed 8 is controlled to ensure the air velocity requirements of the empty tower in the second and above layers of the fluidized bed 8 and the air velocity requirements in the gas inlet pipe of the fourth-stage cyclone 704; the waste salt powder enters from the gas inlet of the first-stage cyclone 701 and falls from the bottom outlet of the fourth-stage cyclone 704 into the top inlet of the fluidized bed 8; the waste salt powder entering the tower plate is in a fluidized state and flows from top to bottom between the sieve plates in the fluidized bed 8 through the powder overflow downcomer; S3: Open and adjust the third valve 1003, cold air enters the first layer at the bottom of the fluidized bed 8, maintaining the air velocity in the empty tower at 0.18 m / s, fluidizing the hot salt in the first layer while cooling it down, reducing the temperature of the salt powder exiting the fluidized bed 8, and at the same time, the cold air is heated and enters the second layer at the bottom of the fluidized bed 8 to recover the heat of the hot salt. S4: Adjust the air flow rate and natural gas C flow rate entering the burner 9 to make the hot air outlet temperature of the burner 9 850℃ and the air pressure of the second air blower 4 12kPa; heat the process air B through the air heater 6 to make the hot spot temperature of the fluidized bed 8 692℃ and the empty tower gas velocity 0.3m / s; adjust the discharge rate of the screw feeder 2 to reach 19kg / min to make the fluidized bed 8 achieve stable operation, and the residence time of the waste salt powder in the fluidized bed 8 is 12min; on the porous tower plates 804 of each stage of the fluidized bed 8, the high temperature air and sodium chloride salt are fully contacted in the fluidized state, so that most of the organic impurities in the sodium chloride salt react with oxygen at high temperature and are oxidized to meet the TOC requirements of the salt powder; process tail gas G is discharged from the top outlet of the first stage cyclone 701 of the preheating oxidizer 7; the salt product powder F cooled to about 200℃ is discharged through the discharge pipe 802; S5: When the temperature at the gas inlet pipe of the 4th stage cyclone 704 is less than 300℃, open and adjust the second valve 1002 to allow some high-temperature air to directly enter the gas inlet pipe of the 4th stage cyclone 704, and maintain the temperature of the gas inlet pipe of the 4th stage cyclone 704 at 300℃.

[0114] After the salt product powder F was naturally cooled, the total organic carbon content in the finished salt was measured to be 107.3 mg TOC / kg, which is equivalent to 32.2 mg / L of the total organic carbon content in a 300 g / L sodium chloride solution used in ion-exchange membrane caustic soda production.

[0115] Comparative Example 2

[0116] This comparative example uses the aforementioned device with the preheating oxidizer 7 removed. The fluidized bed 8 is equipped with a shell 800, which has four layers and a diameter of 0.3m. Inside the shell 800, three layers of porous trays 804 are evenly distributed from top to bottom, with a distance of 1800mm between adjacent layers of porous trays 804. The porosity of each layer of porous trays 804 is 0.5%. A powder overflow pipe 805 is installed on each porous tray 804. The ratio of the cylindrical cross-sectional area of ​​the powder overflow pipe 805 to the bed cross-sectional area is 0.03, and the ratio of the bottom constriction diameter to the upper pipe diameter is 0.5. The distance from the top of the cylindrical part of the powder overflow pipe 805 to the porous tray 804 of that layer is 800mm. The bottom of the constricting funnel of pipe 805 is 400mm away from the lower porous tray 804; the shell 800 wall below the lowest porous tray 804 of fluidized bed 8 is connected to a bottom air inlet 801, and a gas distribution plate 803 is provided in the shell 800 between the bottom air inlet 801 and the lowest porous tray 804 of fluidized bed 8, with an opening ratio of 0.2%; the side air inlet 808 of fluidized bed 8 is connected to the second layer of fluidized bed 8, and an internal component 10 with a catalyst coating is provided between each porous tray 804; a cyclone separator 806 is provided at the top of fluidized bed 8, and the outlet pipe of cyclone separator 806 directly discharges air.

[0117] The inner component 10 with catalyst coating is composed of a connector. The outer wall is wrapped with metal fins, and the outer surface is loaded with a porous ceramic catalytic coating with cordierite micro powder as the skeleton and iron-praseodymium-gadolinium (Fe-Pr-Gd) composite oxide as the active component. The inner component 10 with catalyst coating is made of 2520 heat-resistant steel with a pipe diameter of 10mm. The fins are welded around the steel pipe, and the connector is 0.25m long.

[0118] The method for preparing the catalyst coating on the internal component 10 includes the following steps: (1) Praseodymium nitrate (Pr(NO3)3·6H2O), gadolinium nitrate (Gd(NO3)3·6H2O), and ferric nitrate (Fe(NO3)3·9H2O) were dissolved in deionized water at a molar ratio of Pr:Gd:Fe of 0.8:0.2:1.0. Citric acid was added as a complexing agent, with the molar ratio of citric acid to the total molar amount of metal cations (Pr ions, Gd ions, and Fe ions) being 1.2:1. The mixture was heated and stirred in an 80°C water bath for 1 hour to form a moderately viscous, uniform, transparent, reddish-brown metal complex sol.

[0119] (2) Add inorganic binder and aggregate to the sol obtained in step (1). The inorganic binder is an aluminum dihydrogen phosphate solution with a solid content of 50%, and the amount added is 50% of the dry weight of the sol. The aggregate is cordierite powder with an average particle size of 2 μm, and the mass ratio of the amount of cordierite powder added to the theoretically generated metal oxide in the sol is 1:1. Place the mixture in a ball mill jar and ball mill for 2 hours to prepare a thixotropic composite ceramic slurry with a solid content of about 50 wt%.

[0120] (3) The surface of the internal components made of 2520 heat-resistant steel is roughened by sandblasting (roughness Ra≈4μm), then cleaned with acetone by ultrasonic cleaning to remove oil, and dried at 100℃ for later use.

[0121] (4) Immerse the pretreated internal components vertically into the slurry of step (2) at a pulling speed of 8 mm / min to form a uniform wet film on the surface. Air dry at room temperature for 2 hours.

[0122] (5) Place the air-dried components in a high-temperature furnace and calcine them according to the following procedure: First stage (drying): Heat to 120℃ and keep at that temperature for 1 hour to remove free water; The second stage (self-propagating pore formation): The temperature is slowly increased to 350℃ at 1℃ / min and held for 1 hour. During this stage, citric acid and nitrate ions undergo an in-situ micro-combustion reaction, releasing gas and forming a sponge-like porous structure within the coating. The third stage (ceramization): The temperature is increased to 800℃ at 4℃ / min and held for 3 hours. During this stage, the aluminophosphate solidifies and crosslinks, and the Fe-Pr-Gd oxide crystallizes and anchors on the cordierite framework, ultimately forming a porous ceramic catalytic coating with a thickness of about 50μm, strong bonding, and chlorine resistance.

[0123] This comparative example uses the above-mentioned device with the preheating oxidizer 7 removed to remove organic matter from industrial sodium chloride waste salt through high-temperature oxidation. The total organic carbon content of the waste salt powder is 2250 mg TOC / kg. The specific steps include the following: S1: Open the valves on the air inlet pipe and natural gas inlet pipe of burner 9, and turn on the first air blower 3. Natural gas C and combustion air D enter burner 9 to ignite burner 9 and generate combustion gas. The combustion gas enters air heater 6 through combustion gas inlet 603. After the temperature inside air heater 6 reaches 150°C, turn on the second air blower 4. Process air B enters the heat exchange tube of air heater 6 from air filter 5 through the second air blower 4. The high-temperature combustion gas ejected from burner 9 in air heater 6 exchanges heat with the process air B entering from the air inlet. The heat exchange produces high-temperature process air B, which then enters the second layer at the bottom of fluidized bed 8 through the first valve 1001 and the side air inlet 808 to preheat fluidized bed 8. The combustion exhaust gas E after heat exchange is discharged from combustion exhaust gas E outlet 604. S2: Turn on the screw feeder 2 and add the raw material waste salt powder A with an initial feed moisture content of 10% and a TOC concentration of 2250 mg TOC / kg to the top inlet of the fluidized bed 8 through the material inlet; regulate the flow rate of hot air entering the main bed layer of the fluidized bed 8 by adjusting the second air blower 4 and the first valve 1001 to ensure the empty tower air velocity requirements in the second and above bed layers of the fluidized bed 8; the waste salt powder entering the tower plate is in a fluidized state and flows from top to bottom between the sieve plates of each layer in the fluidized bed 8 through the powder overflow downcomer; S3: Open and adjust the third valve 1003, cold air enters the first layer at the bottom of the fluidized bed 8, maintaining the air velocity in the empty tower at 0.20 m / s, fluidizing the hot salt in the first layer while cooling it down, reducing the temperature of the salt powder exiting the fluidized bed 8, and at the same time, the cold air is heated and enters the second layer at the bottom of the fluidized bed 8 to recover the heat from the hot salt. S4: Adjust the air flow rate and natural gas C flow rate entering the burner 9 to make the hot air outlet temperature of the burner 9 940℃ and the air pressure of the second air blower 4 12kPa; heat the process air B through the air heater 6 to make the hot spot temperature of the fluidized bed 8 631℃ and the empty tower gas velocity 0.3m / s; adjust the discharge rate of the screw feeder 2 to reach 19kg / min to make the fluidized bed 8 achieve stable operation, and the residence time of the waste salt powder in the fluidized bed 8 is 12min; on the porous tower plates 804 of each stage of the fluidized bed 8, the high temperature air and sodium chloride salt are fully contacted in the fluidized state, so that most of the organic impurities in the sodium chloride salt react with oxygen at high temperature and are oxidized, so as to meet the TOC requirements of the salt powder; process tail gas G is discharged from the top outlet of the fluidized bed 8; the salt product powder F cooled to about 200℃ is discharged through the discharge pipe 802.

[0124] After the salt product powder F was naturally cooled, the total organic carbon content in the finished salt was measured to be 94.7 mg TOC / kg, which is equivalent to 28.4 mg / L of the total organic carbon content in a 300 g / L sodium chloride solution used in ion-exchange membrane caustic soda production.

[0125] Comparative Example 3

[0126] This comparative example uses the aforementioned device with the preheating oxidizer 7 removed. The fluidized bed 8 is equipped with a shell 800, which has four layers and a diameter of 0.3m. Inside the shell 800, three layers of porous trays 804 are evenly distributed from top to bottom, with a distance of 1800mm between adjacent layers of porous trays 804. The porosity of each layer of porous trays 804 is 0.5%. A powder overflow pipe 805 is installed on each porous tray 804. The ratio of the cylindrical cross-sectional area of ​​the powder overflow pipe 805 to the bed cross-sectional area is 0.03, and the ratio of the bottom constriction diameter to the upper pipe diameter is 0.5. The distance from the top of the cylindrical part of the powder overflow pipe 805 to the porous tray 804 of that layer is 800mm. The bottom end of the constricting funnel of pipe 805 is 400mm away from the lower porous tray 804; the shell 800 wall below the lowest porous tray 804 of fluidized bed 8 is connected to a bottom air inlet 801, and a gas distribution plate 803 is provided in the shell 800 between the bottom air inlet 801 and the lowest porous tray 804 of fluidized bed 8, with an opening ratio of 0.2%; the side air inlet 808 of fluidized bed 8 is connected to the second layer of fluidized bed 8, and an internal component 10 with a catalyst coating is provided between each layer of porous tray 804; a cyclone separator 806 is provided at the top of fluidized bed 8, and the outlet pipe of cyclone separator 806 directly discharges air; The inner component 10 with catalyst coating is composed of 3 connectors. The outer wall is wrapped with metal fins, and the outer surface is loaded with a porous ceramic catalytic coating with cordierite micro powder as the skeleton and iron-praseodymium-gadolinium (Fe-Pr-Gd) composite oxide as the active component. The inner component 10 with catalyst coating is made of 2520 heat-resistant steel with a pipe diameter of 20mm. The fins are welded around the steel pipe, and the connector is 0.5m long.

[0127] The method for preparing the catalyst coating on the internal component 10 includes the following steps: (1) Praseodymium nitrate (Pr(NO3)3·6H2O), gadolinium nitrate (Gd(NO3)3·6H2O), and ferric nitrate (Fe(NO3)3·9H2O) were dissolved in deionized water at a molar ratio of Pr:Gd:Fe of 0.8:0.2:1.0. Citric acid was added as a complexing agent, with the molar ratio of citric acid to the total molar amount of metal cations (Pr ions, Gd ions, and Fe ions) being 1.2:1. The mixture was heated and stirred in an 80°C water bath for 1 hour to form a moderately viscous, uniform, transparent, reddish-brown metal complex sol.

[0128] (2) Add inorganic binder and aggregate to the sol obtained in step (1). The inorganic binder is an aluminum dihydrogen phosphate solution with a solid content of 50%, and the amount added is 50% of the dry weight of the sol. The aggregate is cordierite powder with an average particle size of 2 μm, and the mass ratio of the amount of cordierite powder added to the theoretically generated metal oxide in the sol is 1:1. Place the mixture in a ball mill jar and ball mill for 2 hours to prepare a thixotropic composite ceramic slurry with a solid content of about 50 wt%.

[0129] (3) The surface of the internal components made of 2520 heat-resistant steel is roughened by sandblasting (roughness Ra≈4μm), then cleaned with acetone by ultrasonic cleaning to remove oil, and dried at 100℃ for later use.

[0130] (4) Immerse the pretreated internal components vertically into the slurry of step (2) at a pulling speed of 6 mm / min to form a uniform wet film on the surface. Air dry at room temperature for 2 hours.

[0131] (5) Place the air-dried components in a high-temperature furnace and calcine them according to the following procedure: First stage (drying): Heat to 130℃ and keep at that temperature for 2 hours to remove free water; The second stage (self-propagating pore formation): The temperature is slowly increased to 350℃ at 1℃ / min and held for 1 hour. During this stage, citric acid and nitrate ions undergo an in-situ micro-combustion reaction, releasing gas and forming a sponge-like porous structure within the coating. The third stage (ceramization): The temperature is increased to 800℃ at 4℃ / min and held for 3 hours. During this stage, the aluminophosphate solidifies and crosslinks, and the Fe-Pr-Gd oxide crystallizes and anchors on the cordierite framework, ultimately forming a porous ceramic catalytic coating with a thickness of about 60μm, strong bonding, and chlorine resistance.

[0132] This comparative example uses the above-mentioned device with the preheating oxidizer 7 removed to remove organic matter from industrial sodium chloride waste salt through high-temperature oxidation. The total organic carbon content of the waste salt powder is 2250 mg TOC / kg. The specific steps include the following: S1: Open the valves on the air inlet pipe and natural gas inlet pipe of burner 9, and turn on the first air blower 3. Natural gas C and combustion air D enter burner 9 to ignite burner 9 and generate combustion gas. The combustion gas enters air heater 6 through combustion gas inlet 603. After the temperature inside air heater 6 reaches 150°C, turn on the second air blower 4. Process air B enters the heat exchange tube of air heater 6 from air filter 5 through the second air blower 4. The high-temperature combustion gas ejected from burner 9 in air heater 6 exchanges heat with the process air B entering from the air inlet. The heat exchange produces high-temperature process air B, which then enters the second layer at the bottom of fluidized bed 8 through the first valve 1001 and the side air inlet 808 to preheat fluidized bed 8. The combustion exhaust gas E after heat exchange is discharged from combustion exhaust gas E outlet 604. S2: Turn on the screw feeder 2 and add the raw material waste salt powder A with an initial feed moisture content of 10% and a TOC concentration of 2250 mg TOC / kg to the top inlet of the fluidized bed 8 through the material inlet; regulate the flow rate of hot air entering the main bed layer of the fluidized bed 8 by adjusting the second air blower 4 and the first valve 1001 to ensure the empty tower air velocity requirements in the second and above bed layers of the fluidized bed 8; the waste salt powder entering the tower plate is in a fluidized state and flows from top to bottom between the sieve plates of each layer in the fluidized bed 8 through the powder overflow downcomer; S3: Open and adjust the third valve 1003, cold air enters the first layer at the bottom of the fluidized bed 8, maintaining the air velocity in the empty tower at 0.20 m / s, fluidizing the hot salt in the first layer while cooling it down, reducing the temperature of the salt powder exiting the fluidized bed 8, and at the same time, the cold air is heated and enters the second layer at the bottom of the fluidized bed 8 to recover the heat from the hot salt. S4: Adjust the air flow rate and natural gas C flow rate entering the burner 9 to make the hot air outlet temperature of the burner 9 900℃ and the air pressure of the second air blower 4 12kPa; heat the process air B through the air heater 6 to make the hot spot temperature of the fluidized bed 8 602℃ and the empty tower gas velocity 0.3m / s; adjust the discharge rate of the screw feeder 2 to reach 19kg / min to make the fluidized bed 8 achieve stable operation, and the residence time of the waste salt powder in the fluidized bed 8 is 12min; on the porous tower plates 804 of each stage of the fluidized bed 8, the high temperature air and sodium chloride salt are fully contacted in the fluidized state, so that most of the organic impurities in the sodium chloride salt react with oxygen at high temperature and are oxidized, so as to meet the TOC requirements of the salt powder; process tail gas G is discharged from the top outlet of the fluidized bed 8; the salt product powder F cooled to about 200℃ is discharged through the discharge pipe 802.

[0133] After the salt product powder F was naturally cooled, the total organic carbon content in the finished salt was measured to be 84.3 mg TOC / kg, which is equivalent to 25.3 mg / L of the total organic carbon content in a 300 g / L sodium chloride solution used in ion-exchange membrane caustic soda production.

[0134] The processing results of Examples 1-6 and Comparative Examples 1-3 are shown in Table 1 below:

[0135] Table 1. Comparison of results for each embodiment and comparative example.

[0136] The comparison shows that the device and method of the present invention have achieved significant technical effects, specifically in the following three aspects: (1) Examples 1 to 6 verified the operational stability and excellent performance of the present invention in the industrial scale-up process. Under the condition that the number of multi-layer fluidized bed layers, multi-stage cyclone stages and the number of series catalytic internal components are gradually increased, when facing waste salt with an initial organic matter concentration as high as 3122 mg TOC / kg, and the feed rate is increased from 19 kg / min to 210 kg / min in a high-throughput condition, the system can still stably control the hot spot temperature of the fluidized bed in the low-temperature range below 600℃. At the same time, the residence time of the material is greatly reduced from 12 min to 4 min, and the total organic carbon content of the final product salt is consistently up to standard. This result shows that the synergistic effect of preheating oxidation, multi-layer fluidization and internal component catalysis effectively breaks through the technical limitations of traditional large-capacity processes that inevitably rely on extremely high reaction temperatures and ultra-long residence times.

[0137] (2) Comparing the test results of Example 1 and Comparative Example 1, it can be seen that the internal components with catalyst coating play a decisive role in the cooling and decarbonization process. Under the condition that the equipment size, feed rate and residence time are exactly the same, even if the hot spot temperature of the fluidized bed in Comparative Example 1, which does not have catalyst internal components, is forcibly increased to 692°C, the organic residue of its product salt is still as high as 107.3 mg TOC / kg. This confirms that the iron-praseodymium-gadolinium composite oxide and cordierite composite catalyst coating can significantly reduce the activation energy of the organic oxidation reaction, which is a key factor in achieving low-temperature and efficient decarbonization, thereby avoiding the industry technical problem that waste salt is prone to melting and scaling at high temperatures.

[0138] (3) Comparison of Comparative Examples 2 and 3 with the Example confirms the irreplaceable role of the preheating oxidizer in terms of heat balance and kinetics. When the multi-stage cyclone preheating oxidizer is removed, causing ambient temperature waste salt to directly enter the main bed, the heat absorption effect of the cold source material forces the system to continuously input extremely high-temperature hot air of 900°C to 940°C in order to barely maintain the bed operating temperature of 600°C to 631°C, and the final removal effect still cannot meet the standard. This proves that the multi-stage cyclone pre-oxidation design plays an irreplaceable role in the pre-drying and heating of the material, and is the physical basis for ensuring the heat balance of the main reaction bed and avoiding a surge in system energy consumption.

[0139] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A high-temperature oxidation removal device for organic matter in sodium chloride waste salt, characterized in that, The device includes: A fluidized bed, comprising a shell, wherein a plurality of porous trays arranged vertically at intervals and a plurality of internal components coated with catalyst are provided inside the shell, and a discharge pipe is provided at the lower end of the shell; An air supply assembly is connected to the lower end of the fluidized bed and is used to supply air to the fluidized bed. A preheating oxidizer is disposed above the fluidized bed and connected to the upper end of the fluidized bed; A feeding assembly is connected to the preheating oxidizer.

2. The high-temperature oxidation removal device for organic matter in sodium chloride waste salt according to claim 1, characterized in that, A gas distribution plate is provided below the bottommost porous tray, and a powder overflow pipe is vertically provided on each porous tray. A feed pipe is provided above the topmost porous tray, and the feed pipe passes through the top surface of the fluidized bed and is connected to the preheating oxidizer.

3. The high-temperature oxidation removal device for organic matter in sodium chloride waste salt according to claim 2, characterized in that, A cyclone separator is provided at the upper end of the fluidized bed. The preheating oxidizer includes multiple cyclone tubes. The lower port of the last cyclone tube is connected to the upper end of the feed pipe. The upper port of the first cyclone tube is connected to the feeding assembly. The side port of the last cyclone tube is connected to the upper end of the cyclone separator that penetrates the top surface of the fluidized bed. The upper port of each of the remaining cyclone tubes is connected to the side port of the cyclone tube above it.

4. The high-temperature oxidation removal device for organic matter in sodium chloride waste salt according to claim 3, characterized in that, The air supply assembly includes a cold air supply end and a hot air supply end. The bottom and side of the lower end of the fluidized bed are respectively provided with a bottom air inlet and a side air inlet. The cold air supply end is connected to the bottom air inlet, and the hot air supply end is connected to the side air inlet and the side opening of the last stage cyclone.

5. The high-temperature oxidation removal device for organic matter in sodium chloride waste salt according to claim 3, characterized in that, The feeding assembly includes an industrial waste salt storage tank and a screw feeder. The inlet and outlet of the screw feeder are respectively connected to the industrial waste salt storage tank and the side opening of the first-stage cyclone.

6. The high-temperature oxidation removal device for organic matter in sodium chloride waste salt according to claim 4, characterized in that, The gas supply assembly includes: A first air blower, the outlet of which is connected to a burner, and the burner is connected to a gas pipeline; An air heater, wherein the burner inlet of the air heater is connected to the burner outlet, and a heat exchange tube is provided inside the air heater; The second air blower has an inlet connected to an air filter and an outlet connected to the air inlet of the heat exchange tube and a cold air supply line. The cold air supply line forms the cold air supply end, and the air outlet of the heat exchange tube forms the hot air supply end. The cold air supply line is connected to the bottom air inlet. The hot air supply end is connected to the side opening and the side air inlet of the final stage cyclone separator through the first and second hot air supply lines, respectively.

7. The high-temperature oxidation removal device for organic matter in sodium chloride waste salt according to claim 1, characterized in that, The internal component includes at least two pipes arranged side by side at intervals. Adjacent pipes are connected by U-shaped connecting pipes to form a serpentine structure. The surfaces of the pipes and the connecting pipes are provided with spirally wound metal fins. The surface of the internal component is loaded with a porous ceramic catalytic coating with cordierite micro powder as the skeleton and iron-praseodymium-gadolinium composite oxide as the active component.

8. The high-temperature oxidation removal device for organic matter in sodium chloride waste salt according to claim 7, characterized in that, The internal component with the catalyst coating is an internal component prepared by the following preparation method, which includes: Step 1: Dissolve ferric nitrate, praseodymium nitrate and gadolinium nitrate in water, add citric acid as a complexing agent, and form a homogeneous metal complex sol under heating and stirring conditions; Step 2: Add aluminum dihydrogen phosphate inorganic binder solution and cordierite micro powder aggregate to the sol obtained in Step 1, and disperse by ball milling to prepare a thixotropic composite ceramic slurry with a solid content of 40-60 wt%. Step 3: The internal components are roughened by sandblasting, then cleaned and dried; Step 4: Immerse the internal components treated in Step 3 into the slurry prepared in Step 2, and form a uniform wet film at a lifting speed of 5-10 mm / min, then dry. Step 5: The internal components obtained in Step 4 are calcined in sections to obtain the internal components with the catalyst coating. The conditions for the section calcination include: first drying at 80-150℃ for 1-3 hours, then heating at 1-2℃ / min to 300-400℃ and holding for 1-2 hours, and finally heating at 3-5℃ / min to 700-900℃ and holding for 2-4 hours.

9. A method for high-temperature oxidation removal of organic matter from sodium chloride waste salt, utilizing the high-temperature oxidation removal device for organic matter from sodium chloride waste salt according to any one of claims 1-8, characterized in that, The method includes: Gas is supplied to the fluidized bed through the gas supply assembly to preheat the fluidized bed and the preheating oxidizer; When the gas temperature at the lower end of the preheating oxidizer reaches the set temperature, the feed is fed through the feeding assembly, and the gas flow rate into the fluidized bed is adjusted to form the set empty tower gas velocity in the fluidized bed and the set gas velocity at the upper end of the preheating oxidizer, so that the waste salt powder particles enter the fluidized bed through the preheating oxidizer and flow downward in the fluidized bed in a fluidized state. Adjusting the air supply parameters of the air supply component cools the lower end of the fluidized bed, reduces the temperature of the salt powder discharged from the fluidized bed, and recovers heat. Adjust the gas supply parameters of the gas supply component to raise the hot spot temperature between the second and third porous trays of the fluidized bed to the operating temperature. Adjust the feed rate of the feeding component to ensure that the waste salt powder particles have a set residence time in the fluidized bed. The gas at the operating temperature comes into contact with the waste salt powder particles in the fluidized state, so that the organic matter in the waste salt powder particles is oxidized, thereby achieving the standard for the total organic carbon in the waste salt powder particles.

10. The method for high-temperature oxidation removal of organic matter from sodium chloride waste salt according to claim 9, characterized in that, Also includes: When the gas temperature at the lower end of the preheating oxidizer is lower than the set temperature, the gas supply mode of the gas supply component is adjusted to supply gas to the lower end of the preheating oxidizer in order to increase the gas temperature at the lower end of the preheating oxidizer and maintain the gas temperature at the lower end of the preheating oxidizer at the set temperature.

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