Electrolytic bath for ionic liquid low-temperature electrolytic aluminum

Abstract

The invention discloses an electrolytic bath for ionic liquid low-temperature electrolytic aluminum, which belongs to the technical field of green metallurgy and comprises an electrolytic bath body, one end of the electrolytic bath body is connected with a peristaltic pump pipeline outlet, and the other end of the electrolytic bath body is connected with a peristaltic pump pipeline inlet; a peristaltic pump is connected between the outlet of the peristaltic pump connecting pipeline and the inlet of the peristaltic pump connecting pipeline so as to adjust the flow velocity of the electrolyte; the electrolysis unit is arranged in the electrolytic bath body and is used for preparing electrolytic aluminum through electrolysis; the slag removal unit is arranged in the electrolytic bath body and corresponds to the electrolysis unit so as to remove electrolytic slag generated by the electrolysis unit; and the electrolytic slag collecting unit is arranged in the electrolytic bath body and is used for collecting the electrolytic slag shoveled by the slag removing unit. The peristaltic pump is adopted to enable the electrolyte to circularly flow, so that the flowing state of the electrolyte can be more effectively controlled, short circuit of the cathode and anode plates caused by accumulation of generated aluminum powder can be prevented through the slag removal shovel, and the electrolysis process is ensured to be smoothly carried out.

Description

Technical Field

[0001] The invention belongs to the technical field of green metallurgy, and in particular relates to an electrolytic cell for low-temperature electrolysis of aluminum using ionic liquids. Background Art

[0002] Aluminum (Al) is the second largest metal after steel. It is widely used in the transportation and construction industries due to its light weight, non-toxicity, ductility, corrosion resistance and other good mechanical properties. However, the Hall-Héroult process is currently widely used in the industry to produce aluminum by electrolysis at a high temperature of nearly 1000°C. Its production power consumption and pollutant emissions are high, which does not meet the strategic goal of green and low-carbon development. The electrolytic aluminum industry urgently needs technological innovation to fundamentally reduce the electrolysis temperature in order to reduce production energy consumption and reduce CO 2 emission.

[0003] In recent years, the electrodeposition of aluminum in a room temperature molten salt (also known as ionic liquid) system with aluminum chloride as the aluminum source has attracted widespread attention. Ionic liquids are room temperature organic molten salts composed entirely of anions and cations. They have the advantages of low volatility, non-flammability, wide electrochemical window, and adjustable structure, and have been widely studied and applied. Electrodeposition of aluminum using ionic liquid electrolytes is an efficient and environmentally friendly method. This system can realize the electrolysis of aluminum at 25-150°C, and the process CO 2 Zero emission, energy consumption is only ~9kW·h·kg -1 , the purity of aluminum can reach more than 99.9%.

[0004] The metal Al ions in the ionic liquid electrolyte need to reach the cathode surface through liquid phase mass transfer to complete the deposition of solid Al. Therefore, the electrolytic slag detached from the cathode during the electrolysis process will accumulate between the anode and cathode, causing a short circuit, thus affecting the electrolysis process. At the same time, the weak ion conductivity of ionic liquids and other characteristics also require the design of a specific structure of the electrolytic cell. Summary of the invention

[0005] In order to solve the above problems, the present invention provides an electrolytic cell for low-temperature electrolysis of aluminum using ionic liquids, which adopts the following technical solutions:

[0006] Electrolytic cell for low-temperature electrolysis of aluminum using ionic liquids, comprising:

[0007] An electrolytic cell body, one end of which is connected to a peristaltic pump pipeline outlet, and the other end of which is connected to a peristaltic pump pipeline inlet; a peristaltic pump is connected between the peristaltic pump pipeline outlet and the peristaltic pump pipeline inlet to adjust the flow rate of the electrolyte;

[0008] An electrolytic unit, the electrolytic unit being disposed in the electrolytic cell body to prepare electrolytic aluminum by electrolysis;

[0009] A slag cleaning unit, which is arranged in the electrolytic cell body and corresponds to the electrolytic unit to remove electrolytic slag generated by the electrolytic unit;

[0010] An electrolytic slag collecting unit is arranged in the electrolytic cell body to collect the electrolytic slag removed by the slag cleaning unit.

[0011] Further, the electrolytic cell body includes a first cell, a second cell, a third cell and a fourth cell; the second cell and the first cell are spaced apart along the length direction of the electrolytic cell body; the third cell and the fourth cell are arranged at the bottom of the electrolytic cell body; the third cell is arranged corresponding to the first cell and is connected to the first cell so that the electrolytic slag falls into the third cell; the fourth cell is arranged corresponding to the second cell and is connected to the second cell; an opening is provided on one end of the third cell close to the second cell so that the third cell is connected to the second cell; the electrolytic unit is arranged in the first cell; and the electrolytic slag collecting unit is arranged in the fourth cell.

[0012] Further, the electrolysis unit includes a cathode plate, an anode plate, a first graphite guide rail and a second graphite guide rail; the first graphite guide rail and the second graphite guide rail are arranged at intervals at both ends of the top of the first tank and are respectively connected to the first tank; the first graphite guide rail and the second graphite guide rail are arranged parallel to each other; the first graphite guide rail and the second graphite guide rail are respectively connected to the cathode of the power supply through a wire;

[0013] The cathode plate and the anode plate are arranged in the first slot at intervals; a first electrode connecting piece is connected to one end of the anode plate in the length direction; two insulating blocks are arranged at both ends of the anode plate in the width direction; one end of the insulating block is connected to the anode plate, and the other end is placed on the first slot; the first electrode connecting piece is connected to the anode of the power supply through a wire;

[0014] A second electrode connecting piece is connected to one end of the cathode plate in the length direction; third electrode connecting pieces are provided at both ends of the cathode plate in the width direction; wherein one end of one of the third electrode connecting pieces is connected to the cathode plate, and the other end is placed on the first groove and in contact with the first graphite guide rail; one end of the other third electrode connecting piece is connected to the cathode plate, and the other end is placed on the first groove and in contact with the second graphite guide rail.

[0015] Furthermore, the cathode plates and the anode plates are provided in plurality respectively; the plurality of cathode plates and the plurality of anode plates are arranged alternately and spaced in sequence.

[0016] Furthermore, the electrolytic slag collection unit includes a filter collection barrel; the filter collection barrel is arranged in the fourth groove to collect the electrolytic slag shoveled away by the slag cleaning unit; a plurality of openings are opened on the barrel wall of the filter collection barrel; a handle is provided on the filter collection barrel; one end of the handle is connected to the filter collection barrel, and the other end extends upward to the outside of the second groove.

[0017] Furthermore, the slag cleaning unit includes a slag cleaning shovel; one end of the slag cleaning shovel passes through the tank body of the electrolytic tank and extends into the third tank to push the electrolytic slag in the third tank through the opening into the filter collection bucket.

[0018] Furthermore, the outlet of the peristaltic pump pipeline is connected to the side wall of the first groove; and the inlet of the peristaltic pump pipeline is connected to the side wall of the second groove.

[0019] Furthermore, a cell body window is arranged on the first side wall of the cell body of the electrolytic cell, and a row of holes is arranged on the second side wall; the first side wall and the second side wall are arranged opposite to each other.

[0020] Furthermore, a liquid switch plug is provided at the bottom of the fourth tank.

[0021] Beneficial effects:

[0022] The electrolytic cell for low-temperature electrolysis of aluminum with ionic liquid provided by the present invention adopts a peristaltic pump to circulate the electrolyte, which can effectively control the flow state of the electrolyte, so as to better meet the requirements of the electrochemical process for material transfer. At the same time, through convection, the solution concentration in the liquid layer near the electrode surface can be changed, effectively reducing the bubble coverage rate, accelerating the detachment of bubbles, thereby promoting ion transmission and improving the electrolysis efficiency; the slag cleaning shovel can prevent the anode and cathode plates from short-circuiting due to the accumulation of aluminum powder, thereby ensuring the smooth progress of the electrolysis process. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the overall structure of the electrolytic cell for low-temperature electrolysis of aluminum using ionic liquids according to the present invention;

[0024] Figure 2 A top view of an electrolytic cell for low-temperature electrolysis of aluminum using ionic liquids according to the present invention;

[0025] Figure 3 for Figure 2 AA section view in;

[0026] Figure 4 This is a schematic diagram of the structure of the anode plate of the electrolytic cell for low-temperature electrolysis of aluminum using ionic liquids according to the present invention;

[0027] Figure 5This is a schematic diagram of the cathode plate structure of an electrolytic cell for low-temperature electrolysis of aluminum using ionic liquids according to the present invention;

[0028] Among them, 1. anode plate; 2. cathode plate; 3. liquid switch plug; 4. connected to the inlet of the peristaltic pump pipeline; 5. connected to the outlet of the peristaltic pump pipeline; 6. slag cleaning shovel; 7. handle; 8. first graphite guide rail; 9. second graphite guide rail; 10. slot body window; 11. first slot; 12. second slot; 13. third slot; 14. fourth slot; 15. row holes; 16. first electrode connecting plate; 17. second electrode connecting plate; 18. third electrode connecting plate; 19. insulating block. DETAILED DESCRIPTION

[0029] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below.

[0030] Example 1

[0031] Reference Figures 1 to 5 , an electrolytic cell for low-temperature electrolysis of aluminum using ionic liquids, comprising:

[0032] The electrolytic cell body has one end connected to a peristaltic pump pipeline outlet 5, and the other end connected to a peristaltic pump pipeline inlet 4; a peristaltic pump is connected between the peristaltic pump pipeline outlet 5 and the peristaltic pump pipeline inlet 4 to adjust the flow rate of the electrolyte;

[0033] An electrolytic unit, the electrolytic unit is arranged in the electrolytic cell body;

[0034] A slag cleaning unit is arranged in the electrolytic cell body and is arranged corresponding to the electrolytic unit to remove the electrolytic slag generated by the electrolytic unit;

[0035] The electrolytic slag collecting unit is arranged in the electrolytic cell body to collect the electrolytic slag removed by the slag cleaning unit.

[0036] Through the above technical solution, the parameters of the external peristaltic pump are adjusted to realize the closed-loop circulation of the electrolyte in the tank body. The peristaltic pump is used to circulate the electrolyte, which can more effectively control the flow state of the electrolyte, thereby better meeting the requirements of the electrochemical process for material transfer.

[0037] In this embodiment, the electrolytic cell body includes a first cell 11, a second cell 12, a third cell 13 and a fourth cell 14; the second cell 12 and the first cell 11 are spaced apart along the length direction of the electrolytic cell body; the third cell 13 and the fourth cell 14 are arranged at the bottom of the electrolytic cell body; the third cell 13 is arranged corresponding to the first cell 11 and is connected to the first cell 11 so that the electrolytic slag generated during the electrolysis process falls into the third cell 13; the fourth cell 14 is arranged corresponding to the second cell 12 and is connected to the second cell 12; an opening is provided on one end of the third cell 13 close to the second cell 12 so that the third cell 13 is connected to the second cell 12; the electrolytic unit is arranged in the first cell 11; and the electrolytic slag collecting unit is arranged in the fourth cell 14.

[0038] In this embodiment, the electrolysis unit includes a cathode plate 2, an anode plate 1, a first graphite guide rail 8 and a second graphite guide rail 9; the first graphite guide rail 8 and the second graphite guide rail 9 are arranged at intervals at both ends of the top of the first tank 11, and are respectively connected to the first tank 11; the first graphite guide rail 8 and the second graphite guide rail 9 are arranged parallel to each other; the first graphite guide rail 8 and the second graphite guide rail 9 are respectively connected to the cathode of the power supply through a wire;

[0039] The cathode plate 2 and the anode plate 1 are arranged in the first slot 11 at intervals; a first electrode connecting piece 16 is connected to one end of the anode plate 1 in the length direction; two insulating blocks 19 are arranged at both ends of the anode plate 1 in the width direction; one end of the insulating block 19 is connected to the anode plate 1, and the other end is placed on the first slot 11; the first electrode connecting piece 16 is connected to the anode of the power supply through a wire;

[0040] A second electrode connecting piece 17 is connected to one end of the cathode plate 2 along the length direction; third electrode connecting pieces are provided at both ends of the cathode plate 2 along the width direction; wherein, one end of a third electrode connecting piece is connected to the cathode plate 2, and the other end is placed on the first groove 11 and contacts the first graphite guide rail 8; one end of another third electrode connecting piece is connected to the cathode plate 2, and the other end is placed on the first groove 11 and contacts the second graphite guide rail 9.

[0041] Among them, the insulating block 19 is preferably a polytetrafluoroethylene insulating block 19.

[0042] Among them, the cathode plate 2 is a cathode pure aluminum plate.

[0043] Through the above technical scheme, polytetrafluoroethylene insulating blocks 19 are provided at both ends of the anode plate 1, and the lower end of the polytetrafluoroethylene insulating block 19 is in contact with the slot body to prevent short circuit after collision with the cathode; the holes on the top of the multiple first electrode connecting plates 16 can connect the multiple anode plates 1 in series through wires, and the top of the anode plate 1 is connected to the power anode using wires; the cathode pure aluminum plate is equipped with third electrode connecting plates 18 on both sides in the width direction, and the two third electrode connecting plates 18 are respectively in contact with the first graphite guide rail 8 and the second graphite guide rail 9 on both sides of the top of the first slot 11, and are connected to the power cathode using wires. The upper electrode connecting plate does not need to be connected to the cathode, and the electrode connecting plates on both sides are connected to the power cathode. The electrode connecting plates on both sides can be adjusted outward to ensure good contact.

[0044] In this embodiment, a plurality of cathode plates 2 and a plurality of anode plates 1 are respectively provided; the plurality of cathode plates 2 and the plurality of anode plates 1 are arranged alternately and spaced apart from each other.

[0045] In this embodiment, the electrolytic slag collection unit includes a filter collection barrel; the filter collection barrel is arranged in the fourth groove 14 to collect the electrolytic slag removed by the slag cleaning unit; a plurality of openings are opened on the barrel wall of the filter collection barrel; a handle 7 is provided on the filter collection barrel; one end of the handle 7 is connected to the filter collection barrel, and the other end extends upward to the outside of the second groove 12.

[0046] In this embodiment, the slag cleaning unit includes a slag cleaning shovel 6; one end of the slag cleaning shovel 6 passes through the tank body of the electrolytic tank and extends into the third tank 13 to push the electrolytic slag in the third tank 13 through the opening into the filter collection bucket.

[0047] Through the above technical solution, such as Figure 3 As shown, once electrolytic slag is produced, the electrolytic slag will be precipitated in the third groove 13 at the bottom under the action of gravity. When the electrolytic slag needs to be sampled or cleaned, the right side of the slag cleaning shovel 6 is pushed in, and the electrolytic slag particles detached from the cathode plate 2 during the electrolysis process can be shoveled into the filter collection bucket in the fourth groove 14. When the slag cleaning shovel 6 has finished cleaning, lift the handle 7 to take out the filter collection bucket, and at the same time, the electrolyte in the filter collection bucket flows out through the opening, and the electrolytic slag remains in the filter collection bucket.

[0048] In this embodiment, the peristaltic pump pipeline outlet 5 is connected to the side wall of the first groove 11 ; the peristaltic pump pipeline inlet 4 is connected to the side wall of the second groove 12 .

[0049] In this embodiment, a tank window 10 is arranged on the first side wall of the tank body of the electrolytic tank, and a row of holes 15 is arranged on the second side wall; the first side wall and the second side wall are arranged opposite to each other.

[0050] Through the above technical solution, such as Figure 3As shown, the flow rate of the electrolyte in the row hole 15 gradually decreases from left to right, and the cathode plate 2 and the anode plate 1 are added and placed alternately from right to left. The circulation state of the electrolyte is observed through the tank window 10, and the flow rate is adjusted to prevent the viscosity of the ionic liquid from being too high during the electrolysis process. The electrolyte circulated outside the peristaltic pump enters the electrolytic cell through the row hole 15 to solve the regional concentration problem during the electrolysis process.

[0051] In this embodiment, a liquid switch plug 3 is provided at the bottom of the fourth groove 14 .

[0052] Through the above technical solution, the liquid switch plug 3 is pulled outward to close the liquid switch plug 3 so that the liquid cannot flow out. The liquid switch plug 3 is pushed inward to open the tank body so that the liquid can be discharged. When the tank body needs to be discharged, the liquid switch plug 3 needs to be connected to the guide tube.

[0053] In this embodiment, a liquid switch plug 3 is provided at the bottom of the fourth groove 14 .

[0054] The method for using the electrolytic cell for low-temperature electrolysis of aluminum using ionic liquid provided by the present invention specifically comprises the following steps:

[0055] S1, cathode plate 2 and anode plate 1 need to be polished before use, then cleaned with acetone, and then washed with 1% (volume ratio) HNO 3 、65%H 3 PO 4 , 5% HCOOH and 29% H 2 O mixed acid for N minutes, and finally rinsed with deionized water. 2 Drying, ensuring the plate surface is clean and dry;

[0056] S2, placing multiple clean cathode plates 2 and multiple anode plates 1 in an interlaced manner from right to left, and connecting multiple anode plates 1 in series through the diameter holes on the top first electrode connecting sheet, and connecting to the power supply anode through a wire;

[0057] S3. The cathode pure aluminum plate is equipped with third electrode connecting pieces 18 on both sides in the width direction. The two third electrode connecting pieces 18 are respectively in contact with the first graphite guide rail 8 and the second graphite guide rail 9 on both sides of the top of the first slot 11. The power cathode is connected by wires. The upper electrode connecting piece does not need to be connected to the cathode. The electrode connecting pieces on both sides are connected to the power cathode. The electrode connecting pieces on both sides can be adjusted outward to ensure good contact.

[0058] S4, connecting the peristaltic pump pipeline inlet 4 and the peristaltic pump pipeline outlet 5 of the electrolytic cell through the peristaltic pump, adjusting the flow rate to realize the closed-loop circulation of the electrolyte in the cell body, and observing whether the electrolyte level is normal through the cell body window 10;

[0059] S5. Turn on the external power supply, set and adjust the constant voltage or constant current mode according to the process requirements for electrolysis, use the slag cleaning shovel 6 for sampling or cleaning during the electrolysis process, push the right side of the slag cleaning shovel 6 into the third slot 13 to send the electrolytic slag into the filter collection bucket, where the operation prompts are as follows: before the electrolysis operation, the pull rod of the slag cleaning shovel 6 must be fully pulled out before performing subsequent operations, and be sure to pay attention to the liquid switch plug 3 is in the closed state; when the filter collection bucket needs to be processed, it is necessary to lift the handle 7 at a slower speed for sampling.

[0060] The above description is only a preferred embodiment of the present invention and does not limit the technical scope of the present invention. Therefore, any slight modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. An electrolytic cell for low-temperature electrolysis of aluminum using ionic liquids, characterized in that: include: An electrolytic cell body, one end of which is connected to a peristaltic pump pipeline outlet, and the other end of which is connected to a peristaltic pump pipeline inlet; a peristaltic pump is connected between the peristaltic pump pipeline outlet and the peristaltic pump pipeline inlet to adjust the flow rate of the electrolyte; An electrolytic unit, the electrolytic unit being disposed in the electrolytic cell body to prepare electrolytic aluminum by electrolysis; A slag cleaning unit, which is arranged in the electrolytic cell body and corresponds to the electrolytic unit to remove electrolytic slag generated by the electrolytic unit; An electrolytic slag collecting unit is arranged in the electrolytic cell body to collect the electrolytic slag removed by the slag cleaning unit.

2. The electrolytic cell for low-temperature electrolysis of aluminum using ionic liquids according to claim 1, characterized in that: The electrolytic cell body includes a first cell, a second cell, a third cell and a fourth cell; the second cell and the first cell are spaced apart along the length direction of the electrolytic cell body; the third cell and the fourth cell are arranged at the bottom of the electrolytic cell body; the third cell is arranged corresponding to the first cell and is connected to the first cell so that the electrolytic slag falls into the third cell; the fourth cell is arranged corresponding to the second cell and is connected to the second cell; an opening is arranged on one end of the third cell close to the second cell so that the third cell is connected to the second cell; the electrolytic unit is arranged in the first cell; and the electrolytic slag collecting unit is arranged in the fourth cell.

3. The electrolytic cell for low-temperature electrolysis of aluminum using ionic liquids according to claim 2, characterized in that: The electrolysis unit comprises a cathode plate, an anode plate, a first graphite guide rail and a second graphite guide rail; the first graphite guide rail and the second graphite guide rail are arranged at intervals at both ends of the top of the first tank and are respectively connected to the first tank; the first graphite guide rail and the second graphite guide rail are arranged parallel to each other; the first graphite guide rail and the second graphite guide rail are respectively connected to the cathode of the power supply through a wire; The cathode plate and the anode plate are arranged in the first slot at intervals; a first electrode connecting piece is connected to one end of the anode plate in the length direction; two insulating blocks are arranged at both ends of the anode plate in the width direction; one end of the insulating block is connected to the anode plate, and the other end is placed on the first slot; the first electrode connecting piece is connected to the anode of the power supply through a wire; A second electrode connecting piece is connected to one end of the cathode plate in the length direction; third electrode connecting pieces are provided at both ends of the cathode plate in the width direction; wherein one end of one of the third electrode connecting pieces is connected to the cathode plate, and the other end is placed on the first groove and in contact with the first graphite guide rail; one end of the other third electrode connecting piece is connected to the cathode plate, and the other end is placed on the first groove and in contact with the second graphite guide rail.

4. The electrolytic cell for low-temperature electrolysis of aluminum using ionic liquids according to claim 3, characterized in that: The cathode plates and the anode plates are provided in plurality respectively; the plurality of cathode plates and the plurality of anode plates are arranged alternately and spaced in sequence.

5. The electrolytic cell for low-temperature electrolysis of aluminum using ionic liquids according to claim 2, characterized in that: The electrolytic slag collection unit comprises a filter collection barrel; the filter collection barrel is arranged in the fourth tank to collect the electrolytic slag removed by the slag cleaning unit; a plurality of openings are provided on the barrel wall of the filter collection barrel; The filter collection bucket is provided with a handle; One end of the handle is connected to the filter collection bucket, and the other end extends upward to the outside of the second groove.

6. The electrolytic cell for low-temperature electrolysis of aluminum using ionic liquids according to claim 5, characterized in that: The slag cleaning unit comprises a slag cleaning shovel; one end of the slag cleaning shovel passes through the tank body of the electrolytic tank and extends into the third tank, so as to push the electrolytic slag in the third tank into the filtering and collecting barrel through the opening.

7. The electrolytic cell for low-temperature electrolysis of aluminum using ionic liquids according to claim 2, characterized in that: The outlet of the peristaltic pump pipeline is connected to the side wall of the first groove; the inlet of the peristaltic pump pipeline is connected to the side wall of the second groove.

8. The electrolytic cell for low-temperature electrolysis of aluminum using ionic liquids according to claim 2, characterized in that: A tank body window is arranged on the first side wall of the tank body of the electrolytic tank, and a row of holes is arranged on the second side wall; the first side wall and the second side wall are arranged opposite to each other.

9. The electrolytic cell for low-temperature electrolysis of aluminum using ionic liquids according to claim 2, characterized in that: A liquid switch plug is arranged at the bottom of the fourth tank.

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