Pyrolysis and purification system for carnallite

Abstract

The utility model discloses a carnallite pyrolysis and purification system which comprises a pyrolysis device, a carnallite storage tank, a starch storage tank, a stirring tank, a granulator, an activated carbon storage tank, a dryer, an oscillator, a filter and an evaporative crystallization system. The device has the advantages that carnallite in the carnallite storage tank and starch in the starch storage tank enter the stirring tank to be mixed, then carnallite pellets are prepared through the pelletizer, the carnallite pellets are dried through the dryer, and then the carnallite pellets and activated carbon particles are fed into the pyrolysis device together to be pyrolyzed; the heat and mass transfer effect can be improved, the carnallite heating time is shortened, and the microwave energy consumption is reduced; on the other hand, the soluble starch is used as an adhesive for granulating the carnallite, and the heat and the raw materials can be fully mixed by pyrolyzing after granulating, so that the heating uniformity of the materials can be improved, and the carnallite in a molten state is prevented from being adhered to a quartz glass or ceramic material tube of pyrolysis equipment to be hardened.

Description

Technical fields:

[0001] This utility model relates to the field of mixed salt purification technology, and more specifically to a mixed salt pyrolysis purification system. Background technology:

[0002] In the treatment of high-salinity wastewater, miscellaneous salts are indirectly generated. These miscellaneous salts have already undergone oxidative decomposition of organic matter in the pre-treatment process; therefore, the organic matter remaining in the miscellaneous salts is mostly recalcitrant, making removal difficult. Purification of miscellaneous salts is the future trend in their treatment and disposal, and the removal of organic matter from miscellaneous salts is key to achieving resource recovery.

[0003] One of the main technologies for purifying mixed salts is microwave pyrolysis. When mixed salts undergo high-temperature pyrolysis under microwave action, the removal rate of organic matter is high. However, molten mixed salts tend to adhere to the quartz glass or ceramic material tubes of the pyrolysis equipment and are difficult to clean. Furthermore, some components of the mixed salts may react chemically with the material tubes, causing damage. Additionally, the microwave pyrolysis reactor has poor mass and heat transfer performance, leading to uneven heating, localized overheating, and affecting process stability, resulting in uneven carbonization and material caking. Moreover, sodium chloride, the main component of mixed salts, has weak microwave absorption capacity, resulting in long heating times, slow rates, and high energy consumption during microwave treatment. Utility Model Content:

[0004] The purpose of this invention is to provide a mixed salt pyrolysis purification system.

[0005] The objective of this utility model is achieved through the following technical solution: a mixed salt pyrolysis purification system, comprising a pyrolysis device, and further comprising a mixed salt storage tank, a starch storage tank, a stirring tank, a granulator, a screening machine, an activated carbon storage tank, a dryer, a vibrator, a filter, and an evaporation crystallization system. The outlets of the mixed salt storage tank and the starch storage tank are connected to the inlet of the stirring tank; the outlet of the stirring tank is connected to the inlet of the granulator; the outlet of the granulator is connected to the inlet of the dryer; the outlets of the dryer and the activated carbon storage tank are both connected to the inlet of the pyrolysis device; the outlet of the pyrolysis device is connected to the inlet of the screening machine; the first outlet of the screening machine is connected to the inlet of the activated carbon storage tank; the second outlet of the screening machine is connected to the inlet of the buffer tank; the outlet of the buffer tank and the water supply pipe are both connected to the inlet of the vibrator; the outlet of the vibrator is connected to the inlet of the filter; and the liquid phase outlet of the filter is connected to the inlet of the evaporation crystallization system.

[0006] Furthermore, the solid phase outlet of the filter is connected to the inlet of the plate and frame filter press, and the outlet of the plate and frame filter press is connected to the pyrolysis carbon silo.

[0007] Furthermore, the evaporation crystallization system includes an evaporator crystallizer, a centrifuge, and a dryer connected in sequence.

[0008] The advantages of this invention are as follows: The mixed salt in the mixed salt storage tank and the starch in the starch storage tank are mixed in a mixing tank, then granulated into mixed salt pellets by a granulator. After drying, they are sent to a pyrolysis device along with activated carbon granules for pyrolysis. On one hand, activated carbon granules are microwave-absorbing materials; their addition during pyrolysis improves heat and mass transfer, shortening the heating time of the mixed salt and reducing microwave energy consumption. On the other hand, soluble starch acts as a binder in the mixed salt granulation process. Pyrolysis after granulation ensures thorough mixing of heat with the raw materials, improving the uniformity of heating and preventing the molten mixed salt from adhering to the quartz glass or ceramic material tubes of the pyrolysis equipment, thus increasing the tubes' lifespan. Furthermore, the pyrolyzed mixture is screened, allowing the activated carbon granules to be recycled. The remaining material is sent to a vibrator with water to dissolve the waste salt, separating it from the pyrolysis carbon. After further processing by an evaporation and crystallization system, it can be recovered as sodium salt. Attached image description:

[0009] Figure 1 This is a schematic diagram of the overall structure of this embodiment.

[0010] 1. Mixed salt storage tank; 2. Starch storage tank; 3. Mixing tank; 4. Granulator; 5. Activated carbon storage tank; 6. Dryer; 7. Vibrator; 8. Filter; 9. Evaporation crystallization system; 10. Plate and frame filter press; 11. Evaporation crystallizer; 92. Centrifuge; 93. Dryer; 94. Pyrolysis carbon silo; 11. Pyrolysis device; 12. Screening machine; 13. Buffer tank; 14. Water supply pipe. Detailed implementation method:

[0011] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0012] like Figure 1As shown, a mixed salt pyrolysis purification system includes a pyrolysis device 11, a mixed salt storage tank 1, a starch storage tank 2, a stirring tank 3, a granulator 4, a screening machine 12, an activated carbon storage tank 5, a dryer 6, a vibrator 7, a filter 8, and an evaporation crystallization system 9. The outlets of the mixed salt storage tank 1 and the starch storage tank 2 are connected to the inlet of the stirring tank 3. The outlet of the stirring tank 3 is connected to the inlet of the granulator 4. The outlet of the granulator 4 is connected to the inlet of the dryer 6. The outlets of the dryer 6 and the activated carbon storage tank 5 are both connected to the inlet of the pyrolysis device 11. The outlet of the pyrolysis device 11 is connected to the inlet of the screening machine 12. The first outlet of the screening machine 12 is connected to the inlet of the activated carbon storage tank 5. The second outlet of the screening machine 12 is connected to the inlet of the buffer tank 13. The outlet of the buffer tank 13 and the water supply pipe 14 are both connected to the inlet of the vibrator 7. The outlet of the vibrator 7 is connected to the inlet of the filter 8. The liquid phase outlet of the filter 8 is connected to the inlet of the evaporation crystallization system 9. The evaporation crystallization system 9 includes an evaporator crystallizer 91, a centrifuge 92, and a dryer 93 connected in sequence. The solid phase outlet of the filter 8 is connected to the inlet of the plate and frame filter press 10, and the outlet of the plate and frame filter press 10 is connected to the pyrolysis carbon silo 94.

[0013] Pyrolysis purification process:

[0014] S1 Granulation

[0015] Soluble starch in starch storage tank 2 and miscellaneous salt in miscellaneous salt storage tank 1 are fed into mixing tank 3 at a mass ratio of 0 to 2:98 and then fed into granulator 4. Water is sprayed to form wet pellets with a particle size of 1.5 cm to 3 cm and a moisture content of 2% to 8%.

[0016] S2 drying

[0017] The pellets obtained from S1 are fed into dryer 6 for drying. The drying time is 0.5h to 1.5h and the temperature is 80℃ to 100℃ to obtain mixed salt pellets with a moisture content of less than 2%.

[0018] S3 pyrolysis

[0019] The mixed salt pellets obtained by S2 and the 0.5cm activated carbon particles in the activated carbon storage tank 5 are mixed at a mass ratio of 9:1 to 2.25 and added to the pyrolysis device 11 for pyrolysis. The pyrolysis temperature is 350℃ to 700℃ and the time is 1h to 3h to obtain a mixture.

[0020] S4 screening

[0021] The pyrolysis mixture is screened by screening machine 12 to separate activated carbon particles, which are then sent back to activated carbon storage tank 5 for recycling to obtain purified pellets.

[0022] S5 Shock

[0023] The purified pellets obtained in S4 are fed into the shaker 7 and water is added through the water supply pipe 14. After shaking, they are filtered through the filter 8 to remove pyrolytic carbon and obtain concentrated brine. The filtered pyrolytic carbon is then pressed through the plate and frame filter press 10 to obtain pyrolytic carbon cake. The pyrolytic carbon cake is stored in the pyrolytic carbon silo 94 and can be reused as activated carbon after further processing.

[0024] S6 Evaporation Crystallization

[0025] The concentrated brine obtained from S5 is evaporated and crystallized. It is then passed through an evaporator crystallizer 91 for evaporation and crystallization, a centrifuge 92 for centrifugation and separation, and a dryer 93 for drying to obtain purified crystalline salt.

[0026] The concentrated brine obtained from S5 was evaporated and crystallized to obtain purified crystalline salt.

[0027] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A pyrolysis purification system for mixed salts, comprising a pyrolysis device, characterized in that, It also includes a mixed salt storage tank, a starch storage tank, a mixing tank, a granulator, a screening machine, an activated carbon storage tank, a dryer, a vibrator, a filter, and an evaporation crystallization system. The outlets of the mixed salt storage tank and the starch storage tank are connected to the inlet of the mixing tank. The outlet of the mixing tank is connected to the inlet of the granulator. The outlet of the granulator is connected to the inlet of the dryer. The outlets of the dryer and the activated carbon storage tank are both connected to the inlet of the pyrolysis device. The outlet of the pyrolysis device is connected to the inlet of the screening machine. The first outlet of the screening machine is connected to the inlet of the activated carbon storage tank. The second outlet of the screening machine is connected to the inlet of the buffer tank. The outlet of the buffer tank and the water supply pipe are both connected to the inlet of the vibrator. The outlet of the vibrator is connected to the inlet of the filter. The liquid phase outlet of the filter is connected to the inlet of the evaporation crystallization system.

2. The mixed salt pyrolysis purification system according to claim 1, characterized in that, The solid phase outlet of the filter is connected to the inlet of the plate and frame filter press, and the outlet of the plate and frame filter press is connected to the pyrolysis carbon silo.

3. The mixed salt pyrolysis purification system according to claim 1, characterized in that, The evaporation crystallization system includes an evaporator crystallizer, a centrifuge, and a dryer connected in sequence.

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