Intermittent melt production equipment and process

Abstract

The invention discloses intermittent melt production equipment and a process. The equipment comprises a reaction kettle body, a tank cover, a tail gas treatment system and a vacuum discharging system, wherein the reaction kettle body is used for melt raw material reaction and melt storage; the tank cover is used for sealing the tank body; the tail gas treatment system is used for collecting, treating and discharging waste gas generated in the reaction process; and the vacuum discharging system is used for pumping the melt which is produced by the reaction kettle body and is detected to be qualified into a special melt storage tank through vacuum negative pressure to be stored or transferred for use. According to the invention, melt production can be realized, the melt production efficiency can be improved, the operation difficulty can be reduced, the equipment investment cost can be reduced, the melt quality can be observed in real time in the production process, the quality risk can be reduced, the quality of the produced melt can be ensured, waste gas generated in the production process can also be absorbed and treated, and the environmental protection requirement can be met.

Description

Technical Field

[0001] The present invention belongs to the technical field of molten salt production, and particularly relates to an intermittent melt production device and process. Background Art

[0002] The operating temperature of a sodium-nickel battery is 250 - 325°C, and liquid sodium tetrachloroaluminate melt is used as the electrolyte. As a medium for conducting sodium ions during charge and discharge, the production of sodium tetrachloroaluminate requires co-melting of sodium chloride and aluminum chloride at a temperature above 190°C. The high-temperature sodium tetrachloroaluminate melt has extremely strong corrosiveness, and during the production process, the melt is extremely likely to react with moisture or other impurities in the air and deteriorate. Existing melt production equipment has problems such as being unable to observe the melt state in a timely manner and the quality of the produced melt cannot be guaranteed. Among them, continuous production equipment also requires additional stirring and sedimentation equipment, with a cumbersome design and complex operation. Therefore, the production of sodium tetrachloroaluminate melt, which is highly corrosive at high temperatures and sensitive to air, while ensuring compliance with environmental protection requirements, is a complex engineering problem and also a technical problem that needs to be solved currently.

[0003] The present invention can solve the above problems through an intermittent melt production device and process, and can also be applied to the production of tetrachloroaluminate homologues such as lithium tetrachloroaluminate and potassium tetrachloroaluminate. Summary of the Invention

[0004] Aiming at the deficiencies in the prior art, the purpose of the present invention is to provide an intermittent melt production device and process. By using this device and process, the present invention can not only realize the production of melt, but also improve the melt production efficiency, reduce the operation difficulty, reduce the equipment investment cost. At the same time, the melt quality can be observed in real time during the production process, reducing the quality risk and ensuring the quality of the produced melt. The waste gas generated during the production process can also be absorbed and treated to meet environmental protection requirements.

[0005] To achieve the above objectives, the present invention provides the following technical solutions:

[0006] An intermittent melt production device, comprising: a reaction kettle body, a tank cover, a tail gas treatment system, and a vacuum discharging system; wherein,

[0007] The reaction kettle body is used for the reaction of melt raw materials and melt storage, and includes a tank body, a heat preservation shell, a temperature control component, and a ventilation pipeline;

[0008] The tank cover is used to seal the tank body to prevent moisture or other impurities in the air from entering the melt, and at the same time recover the sublimated raw materials, and includes a cover body, a handle, and a sampling port;

[0009] The tail gas treatment system is used for collecting, treating, and discharging the waste gas generated during the reaction process, and includes a gas collecting cover, an exhaust pipeline, and a tail gas absorption tower;

[0010] The vacuum discharging system is used to extract the qualified melt produced by the reactor body to a special storage tank for the melt through vacuum negative pressure for storage or transfer and use.

[0011] Preferably, the tank body is a vertical cylindrical structure with an open upper end, and a pure nickel or Hastelloy lining is provided inside the tank body, and is slidably fitted into a stainless steel outer lining.

[0012] Preferably, the heat preservation shell is made of stainless steel, covers the outer periphery and bottom of the tank body, and the closed space between the stainless steel outer layer and the tank body is filled with heat-insulating and heat-preserving materials. More preferably, the heat-insulating and heat-preserving materials are rock wool or fiberglass wool.

[0013] Preferably, the temperature control component includes a heating device and a temperature measuring probe; the heating device is arranged on the outer wall of the tank body and includes a ceramic heating sheet, an electric heating tape, an electric heating plate, an electric heating tube or an electric heating wire; the temperature measuring probe is arranged on the outer wall and bottom of the tank body.

[0014] Preferably, the ventilation pipe penetrates through the side wall of the tank body from the upper part of the tank body, and the flow rate of the protective gas introduced is adjusted through a flow valve and / or a proportional valve arranged on the ventilation pipe, so that the melt is isolated from the external air atmosphere.

[0015] Preferably, the handle is welded to the cover body, and the sampling port is arranged on the plane of the cover body.

[0016] Preferably, the cover of the tank is made of thin nickel plate or Hastelloy plate.

[0017] Preferably, a heat preservation cotton cover is detachably arranged on the cover of the tank, and the heat preservation cotton cover is made of a fiberglass-sewn outer sleeve and filled with heat preservation materials inside.

[0018] The cover of the tank of the present invention adopts a lightweight design, which is convenient for taking, loading and unloading. Through the cover of the tank, manual stirring operation can be carried out, and at the same time, sampling and observation can be carried out during the production process. When the color of the melt is black or gray, or there are suspended particles, the sedimentation time is prolonged. When the color of the melt is yellow, aluminum foil is added for further reaction to ensure the color state of the melt and timely treatment to ensure the quality of the melt.

[0019] Preferably, the gas collecting cover covers the upper opening of the tank body and is connected to the tail gas absorption tower through the exhaust pipe. The gas collecting cover and the exhaust pipe are made of stainless steel or corrosion-resistant polypropylene, and the tail gas absorption tower uses an alkaline treatment liquid for waste gas treatment, and the alkaline liquid is one of sodium hydroxide solution, sodium carbonate solution or sodium bicarbonate solution.

[0020] The present invention also provides a production process using the above intermittent melt production equipment, which includes the following steps: adding raw materials prepared with melt into the reaction kettle body, where the raw materials include sodium chloride, anhydrous aluminum trichloride, and aluminum foil, controlling the temperature of the reaction kettle body, maintaining the introduction of protective gas, heating the added raw materials to react, stirring after a certain period of preliminary reaction, settling the stirred melt in the body, and finally removing and storing or using the melt product through a vacuum discharging system.

[0021] Further, the steps of the production process are specifically as follows:

[0022] Feeding: Preheat and bake the body, introduce protective gas, open the raw material barrel of anhydrous aluminum trichloride, add a certain weight of sodium chloride and aluminum foil into the barrel, turn the raw material barrel multiple times for stirring and premixing, add the premixed raw materials into the reaction kettle body, evenly spread sodium chloride and aluminum foil on the upper layer of the raw materials, install the tank cover, and close the gas collecting cover;

[0023] Stirring: Open the gas collecting cover, remove the tank cover, use a melt stirring paddle for stirring, stop stirring after fully stirring until there is no white smoke or bubbles in the melt, install the tank cover, and close the gas collecting cover;

[0024] Settling: Keep the temperature in the body and wait for the suspended solid matter to settle to the bottom of the melt;

[0025] Sampling: Use a sampling spoon to pass through the sampling port of the tank cover or sample after removing the tank cover, observe the color and state of the melt. When the melt is white and clear, it is qualified. When the color of the melt is black or gray, or there are suspended particulate matters, extend the settling time. When the color is yellow, add aluminum foil; conduct component detection on the melt sample;

[0026] Discharging: After the component detection is qualified, use a vacuum discharging system for discharging and transferring.

[0027] Further, the preheating temperature in the feeding step is 80 - 110 °C. After adding the raw materials, the reaction temperature is 200 - 250 °C, and the reaction time is 10 - 24 hours.

[0028] Further, the stirring time in the stirring step is 3 - 15 minutes.

[0029] Further, the settling time in the settling step is 24 - 84 hours.

[0030] Further, the molar ratio of sodium chloride to anhydrous aluminum trichloride is 1.03 - 1.14:1; the mass ratio of aluminum foil to anhydrous aluminum trichloride is 1:1000 - 5:1000.

[0031] The beneficial effects of the present invention are:

[0032] The melt production equipment of the present invention ensures isolation from the air atmosphere during the melt reaction process, also avoids the mixing of other impurities caused by the equipment into the melt, reduces the investment in stirring, sedimentation and heating equipment, and lowers the equipment investment cost. The equipment is simple and reliable, has a low manufacturing cost and is easy to operate. At the same time, it is convenient to observe the melt quality during the production process, can identify melt abnormalities in a timely manner, and process the melt with abnormalities in a timely manner, reducing quality risks and ensuring the quality of the produced melt. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 FIG. is a schematic structural diagram of the batch melt production equipment provided in Embodiment 1 of the present invention.

[0034] Figure 2 FIG. is a schematic structural diagram of the melt reaction kettle body provided in Embodiment 1 of the present invention.

[0035] Figure 3 This is the body provided in Embodiment 1 of the present invention Figure 2 The enlarged structural diagram at position A in

[0036] Figure 4 FIG. is a schematic structural diagram of the tank cover provided in Embodiment 1 of the present invention.

[0037] Figure 5 FIG. is a schematic structural diagram of the gas collecting cover provided in Embodiment 1 of the present invention.

[0038] Figure 6 FIG. is a schematic structural diagram of the flanging structure at the mouth of the tank lining provided in Embodiment 2 of the present invention.

[0039] Figure 7 FIG. is a schematic structural diagram of the heat insulation cotton cover provided in Embodiment 1 of the present invention.

[0040] Figure 8 FIG. is a schematic diagram of the discharge transfer of the vacuum discharge system provided in Embodiment 1 of the present invention.

[0041] Reference numerals: body 1, tank cover 2, tail gas absorption tower 3, exhaust pipe 4, tank body 5, heat insulation shell 6, heating device 7, temperature measuring probe 8, ventilation pipe 9, inner lining 10, outer lining 11, handle 12, sampling port 13, gas collecting cover 14, heat insulation cotton cover 15, transfer pipe 16, storage tank 17 DETAILED DESCRIPTION OF THE EMBODIMENTS

[0042] In order to make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be described in detail below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other implementation manners obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope protected by the present invention.

[0043] Unless otherwise defined, the technical terms or scientific terms used in this disclosure shall have the ordinary meanings understood by those of ordinary skill in the art to which this invention pertains.

[0044] Example 1:

[0045] This example provides a melt device, which includes a reactor body 1, a tank cover 2, a tail gas treatment system 3, and a vacuum discharging system 4.

[0046] The melt reactor body 1 in this example includes a tank body 5, a thermal insulation shell 6, a temperature control component, and a ventilation pipe 9.

[0047] The tank body 5 is a vertical cylindrical structure with an open upper side. A pure nickel or Hastelloy lining 10 is provided inside the tank body 5, and it is slidably fitted into a stainless steel outer lining 11. Through the combination of the inner and outer linings, the corrosion resistance of the tank body 5 can be improved, the service life of the equipment can be extended, and at the same time, impurity element pollution caused by the equipment can be avoided, ensuring that the melt meets the required quality.

[0048] A ventilation pipe 9 is provided at the upper part of the tank body 5. The ventilation pipe 9 penetrates through the side walls of the inner and outer linings of the tank body 5 from the upper part of the tank body 5 and extends into the internal space of the tank body 5. The flow rate of the protective gas introduced is controlled by a flow valve and / or a proportional valve provided on the pipe, and the melt is isolated from the air atmosphere through the protective gas, thereby avoiding the reaction of the melt with moisture or other impurities in the air.

[0049] The thermal insulation shell 6 in this example covers the outside and bottom of the stainless steel outer lining 11 of the tank body 5. The thermal insulation shell 6 is made of stainless steel, and the closed space between the thermal insulation shell 6 and the tank body 5 is filled with a heat-insulating material. The heat-insulating material is rock wool or fiberglass wool, etc. At the same time, a thermal insulation cotton cover 15 is preferably provided, and the thermal insulation cotton cover 15 is detachably covered above the reactor tank cover 2. The thermal insulation effect of the tank body 5 can be further enhanced by using this thermal insulation cotton cover 15.

[0050] The temperature control component in this example includes a heating device 7 and a temperature measuring probe 8. The heating device 7 includes a ceramic heating sheet, an electric heating tape, an electric heating plate, an electric heating tube, or an electric heating wire, etc. The heating device 7 is provided on the outer wall of the stainless steel outer lining 11 of the tank body 5. The heating device 7 can operate independently in blocks to ensure uniform temperature and can continue to maintain the heating effect after partial failures. The temperature measuring probe 8 is provided on the side wall and bottom of the stainless steel outer lining 11 of the tank body 5. The temperature of the tank body 5 is monitored in real time through the temperature measuring probe 8, and the output power of the heating device 7 is controlled to keep the temperature inside the reactor constant.

[0051] The lid 2 of this example is made of thin nickel plate or Hastelloy plate, with a lightweight design. A handle 12 is welded to the lid body. The lid 2 can be taken, loaded, and unloaded through the handle 12. A sampling port 13 (i.e., exhaust port) is provided on the plane of the lid 2. Through the sampling port 13, the melt can be sampled and observed without opening the lid 2, and at the same time, the corrosive waste gas generated during the melt production process can be discharged.

[0052] The tail gas treatment system described in this example includes a gas collection cover 14, an exhaust pipe 4, and a tail gas absorption tower 3. The gas collection cover 14 covers the upper side of the tank body 5 to prevent waste gas from overflowing. The gas collection cover 14 can be turned upwards to open, facilitating operations such as melt feeding, discharging, and stirring. The exhaust pipe 4 is connected to the tail gas absorption tower 3. A water tank is provided under the tail gas absorption tower 3. An alkaline substance is added to the treatment liquid in the water tank to form an alkaline solution. The alkaline solution in the water tank is sprayed through a water pump to absorb and treat the corrosive waste gas generated during the melt production process, and finally, the air meeting the environmental protection requirements is discharged. The alkaline solution is one of sodium carbonate solution, sodium bicarbonate solution, or sodium hydroxide solution. The pH value of the alkaline solution is controlled to be greater than or equal to 8, which can be 8, 8.5, 9, 10, 11, 12, or 13, etc. In this embodiment, the pH value of the treatment liquid is controlled to be 10 - 14. The waste gas generated during the melt production process is absorbed and treated by the tail gas treatment system to meet the environmental protection requirements.

[0053] Reference Figures 1 to 8 , this batch production process specifically includes:

[0054] First, install the reaction kettle lid 2, close the gas collection cover 14 for preheating, and introduce a protective gas through the ventilation pipe 9 to fully dry the reaction kettle body 5 and change the internal air atmosphere of the body 5 into a protective gas atmosphere. The preheating temperature can be 80°C, 85°C, 90°C, 95°C, or 100°C, etc.; the full drying time can be 50 minutes, 60 minutes, 70 minutes, or 100 minutes, etc.; the protective gas can be nitrogen, helium, neon, or argon, etc.; the flow rate of the protective gas can be 0.2 SLM, 0.4 SLM, 0.6 SLM, 0.8 SLM, 1.0 SLM, 2.0 SLM, 6.0 SLM, or 10.0 SLM, etc.

[0055] Then, open the raw material barrel of anhydrous aluminum trichloride, add a certain weight of sodium chloride and aluminum foil into the barrel, and turn the raw material barrel over multiple times for premixing of the raw materials. After the premixing is completed, add the raw materials into the reaction kettle body 5, and evenly spread a certain weight of sodium chloride and aluminum foil on the upper layer of the premixed materials. The total molar ratio of the sodium chloride to the anhydrous aluminum trichloride is greater than or equal to 1.03:1 and less than or equal to 1.14:1. For example, the molar ratio can be 1.03:1, 1.05:1, 1.1:1, 1.14:1, etc.; the mass ratio of the aluminum foil to the anhydrous aluminum trichloride is 1:1000 - 5:1000. For example, the mass ratio of the aluminum foil to the anhydrous aluminum trichloride can be 1:1000, 2:1000, 2.5:1000, 3:1000, 5:1000, etc.

[0056] After the feeding is completed, install the reaction kettle cover 2, close the gas collecting cover 14, and set the temperature of the reaction kettle body 5 to the reaction temperature. The reaction temperature is greater than or equal to 200 °C and less than or equal to 250 °C. For example, the temperature can be 200 °C, 205 °C, 210 °C, 220 °C, 230 °C, 250 °C, etc.

[0057] After the temperature of the reaction kettle body 5 rises, the raw materials melt and start to react. Open the reaction kettle gas collecting cover 14, remove the reaction kettle cover 2, and use a stirring paddle made of pure nickel or Hastelloy for stirring. After the stirring is completed, there should be no white smoke or bubbles in the melt in the body 5. The preliminary reaction time is greater than or equal to 10 hours and less than or equal to 24 hours. For example, the preliminary reaction time can be 10 hours, 12 hours, 14 hours, 20 hours, 24 hours, etc.; the stirring time is greater than or equal to 3 minutes and less than or equal to 15 minutes. For example, the stirring time can be 3 minutes, 5 minutes, 10 minutes, 15 minutes, etc.

[0058] After the stirring, install the reaction kettle cover 2, close the gas collecting cover 14, and let the melt stand for sedimentation to make the solid substances suspended in the melt settle to the bottom of the melt. The sedimentation time is greater than or equal to 24 hours and less than or equal to 84 hours. For example, the sedimentation time can be 24 hours, 26 hours, 30 hours, 48 hours, 66 hours, 84 hours, etc.

[0059] After the sedimentation is completed and the composition of the melt sample is detected to be qualified, transfer the melt product out through the vacuum discharging system to be stored in the storage tank 17 or transferred for use.

[0060] In this embodiment, during the sedimentation process after the stirring and before the discharging and transferring, use a sampling spoon made of pure nickel or Hastelloy to take samples through the sampling port 13 on the cover 2 of the tank, or open the gas collecting cover 14 and remove the cover 2 to take samples. Observe that the color of the melt is white. If the melt is clear and transparent, it is qualified. If the color of the melt is black or gray and there are suspended particles, extend the sedimentation time; if the color of the melt is yellow, add aluminum foil and continue the reaction.

[0061] Example 2

[0062] Compared with Example 1, the difference in this example lies in that a flanging is additionally provided outward at the mouth of the pure nickel or Hastelloy lining 10 of the tank body 5 described in Example 1. Adding this flanging can seal the upward open gap existing between the lining 10 and the outer lining 11 of the tank body 5 after the sliding fit installation, prevent the melt and water vapor from infiltrating between the inner and outer linings, avoid the corrosion of the stainless steel outer lining 11, and also avoid the bulging and rupture of the lining 10 caused by the generation of gas between the inner and outer linings, further extending the service life of the equipment.

[0063] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. An intermittent melt production equipment, characterized in that: include: Reactor body, tank cover, tail gas treatment system and vacuum discharge system; among them, The reactor body is used for melt raw material reaction and melt storage, including a tank body, an insulation shell, a temperature control component and a ventilation pipe; The can cover is used to seal the can body to prevent moisture or other impurities in the air from entering the melt and to recover the sublimated raw materials, and comprises a cover body, a handle and a sampling port; The tail gas treatment system is used to collect, treat and discharge the waste gas generated during the reaction process, and includes a gas collecting cover, an exhaust pipe and a tail gas absorption tower; The vacuum discharging system is used to extract the qualified melt produced by the reactor body through vacuum negative pressure into a storage tank dedicated to the melt for storage or transfer for use.

2. The intermittent melt production equipment according to claim 1, characterized in that: The tank body is a vertical cylindrical structure with an open upper end. A pure nickel or Hastelloy inner lining is arranged in the tank body, and a stainless steel outer lining is slidably mounted therein.

3. The intermittent melt production equipment according to claim 1, characterized in that: The heat-insulating shell is made of stainless steel and is arranged around the periphery and bottom of the tank body, and the closed space between the stainless steel outer layer and the tank body is filled with heat-insulating material. More preferably, the heat-insulating material is rock wool or glass fiber wool.

4. The intermittent melt production equipment according to claim 1, characterized in that: The temperature control component includes a heating device and a temperature measuring probe; the heating device is arranged on the outer wall of the tank body, and includes a ceramic heating plate, an electric heating belt, an electric heating plate, an electric heating tube or an electric heating wire; the temperature measuring probe is arranged on the outer wall and bottom of the tank body.

5. The intermittent melt production equipment according to claim 1, characterized in that: The ventilation pipe runs through the side wall of the tank body from the upper part of the tank body, and the flow rate of the protective gas introduced is adjusted by a flow valve and / or a proportional valve arranged on the ventilation pipe to isolate the melt from the external air atmosphere.

6. The intermittent melt production equipment according to claim 1, characterized in that: The handle is welded to the cover body, and the sampling port is arranged on the plane of the cover body; the material of the tank cover is a thin nickel plate or a Hastelloy plate; the tank cover is also detachably provided with a thermal insulation cotton cover, and the thermal insulation cotton cover is made of a glass fiber sewn outer cover and is filled with thermal insulation material inside.

7. The intermittent melt production equipment according to claim 1, characterized in that: The gas collecting cover is arranged at the opening of the upper end of the tank body and is connected to the tail gas absorption tower through the exhaust pipe. The gas collecting cover and the exhaust pipe are made of stainless steel or corrosion-resistant polypropylene. The tail gas absorption tower uses an alkaline treatment liquid to treat the waste gas, and the alkaline liquid is one of sodium hydroxide solution, sodium carbonate solution or sodium bicarbonate solution.

8. The production process of the intermittent melt production equipment according to any one of claims 1 to 7, characterized in that: The method comprises the following steps: adding raw materials for melt preparation into a reactor tank body, wherein the raw materials include sodium chloride, anhydrous aluminum chloride and aluminum foil, controlling the temperature of the reactor tank body, maintaining the introduction of protective gas, heating the input raw materials for reaction, stirring after a certain period of preliminary reaction, settling the stirred melt in the tank body, and finally removing the melt product through a vacuum discharging system for storage or use.

9. The production process according to claim 8, characterized in that: The specific steps are: Feeding: preheat and bake the tank body, introduce protective gas, open the anhydrous aluminum chloride raw material barrel, add a certain weight of sodium chloride and aluminum foil into the barrel, turn the raw material barrel over several times to stir and premix, add the premixed raw materials into the reactor body, evenly spread sodium chloride and aluminum foil on the upper layer of the raw materials, install the tank cover, and close the gas collecting cover; Stirring: Open the gas collecting cover, remove the tank cover, use the melt stirring paddle to stir, stir thoroughly until there is no white smoke or bubbles in the melt, stop stirring, install the tank cover, and close the gas collecting cover; Sedimentation: Keep the temperature in the tank and wait for the suspended solids to settle to the bottom of the melt; Sampling: Use a sampling spoon to pass through the sampling port of the tank cover, or take a sample after removing the tank cover, and observe the color of the melt. If the melt is white and clear, it is qualified. If the melt color is black or gray, or there are suspended particles, extend the sedimentation time. If the color is yellow, add aluminum foil; the melt sample is tested for composition; Discharging: After the ingredients are tested and qualified, the vacuum discharging system is used for discharging and transfer.

10. The production process according to claim 9, characterized in that: The preheating temperature of the feeding step is 80-110° C., after the raw materials are added, the reaction temperature is 200-250° C., and the reaction time is 10-24 hours; the stirring time of the stirring step is 3-15 minutes; the sedimentation time of the sedimentation step is 24-84 hours; the molar ratio of the sodium chloride to anhydrous aluminum chloride is 1.03-1.14:1; and the mass ratio of the aluminum foil to anhydrous aluminum chloride is 1:1000-5:1000.

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