Device, system and method for quantitatively discharging liquid lithium from lithium electrolysis cell

Abstract

The present invention relates to the technical field of lithium electrolysis cells. A device, system and method for quantitatively discharging liquid metallic lithium from a lithium electrolysis cell. The device comprises a lithium collection device and a lithium buffer tank (5) connected to the lithium collection device, wherein an inlet of the lithium buffer tank (5) is connected to a lithium electrolysis cell (1) by means of the lithium collection device, so as to receive liquid lithium from the lithium electrolysis cell (1) and temporarily store the liquid lithium in the lithium buffer tank (5), and an outlet of the lithium buffer tank (5) is connected to a lithium storage tank (10) via a lithium transfer pipe (7), such that when a liquid level of the liquid lithium in the lithium buffer tank (5) reaches a high limit, a valve (8) arranged on the lithium transfer pipe (7) is opened to allow the liquid lithium in the lithium buffer tank (5) to be discharged, under the action of pressure, through the lithium transfer pipe (7) into the lithium storage tank (10) located at a lower position, and after a certain amount of liquid lithium is discharged, the valve (8) is closed. The device enables automatic, quantitative and safe transfer of metallic lithium in the lithium electrolysis cell, avoiding secondary contamination during a lithium discharge process, and reducing the difficulty of system maintenance and the labor intensity of workers.

Description

Device, system and method for quantitatively guiding liquid lithium from lithium electrolytic cell TECHNICAL FIELD

[0001] The present application relates to the technical field of lithium electrolytic cell, and particularly relates to a device, system and method for quantitatively guiding liquid lithium from lithium electrolytic cell. BACKGROUND

[0002] In the current metal lithium electrolytic industry, the guiding of the metal lithium liquid produced in the cell often needs workers to use tools to scoop out and then cast into crude lithium ingots. This operation has great work intensity and safety risk, and at the same time, the metal lithium will be in contact with the air to cause secondary oxidation of lithium, resulting in a decrease in metal purity, a decrease in current efficiency and an increase in production cost.

[0003] Chinese patent application CN220685268U discloses a metal lithium electrolytic cell capable of automatically discharging lithium, and the discharging process is realized by enriching the metal lithium in the electrolytic cell by a lithium collecting device and overflowing the lithium liquid by a flow guiding device. However, in the patent application, the discharging amount in the discharging process is difficult to control, and with the extension of working time, part of the metal lithium or lithium oxide will be left in the overflow pipe, affecting the discharging effect. Chinese patent application CN220685267U discloses a lithium electrolytic cell automatic lithium discharging device, which collects the metal lithium by a lithium collecting furnace connected with the lithium discharging pipe of the electrolytic cell, and the lithium collecting furnace is internally provided with a three-stage siphon flow guiding component to guide the metal lithium. However, the lithium discharging device still has the problems of great difficulty in maintaining the lithium discharging pipe and complex internal structure of the lithium collecting furnace.

[0004] In view of the above disadvantages and deficiencies of the prior art, considering the requirements of automation, precision and safety and environmental protection in the field of lithium electrolytic production, how to enable the lithium discharging device to automatically, quantitatively and safely transfer the liquid metal lithium while reducing the work intensity of replacement and maintenance during the working process of the system is a problem to be solved by those skilled in the art. SUMMARY

[0005] In view of the above disadvantages and deficiencies of the prior art, the present application provides a device and method for quantitatively guiding liquid metal lithium from a lithium electrolytic cell, which aims to realize automatic, quantitative and safe transfer of the metal lithium in the cell, and reduce the maintenance difficulty of the system and the labor intensity of workers. Further, the present application also aims to avoid secondary pollution in the lithium discharging process.

[0006] To achieve the above object, in one aspect, the present application provides a device for quantitatively discharging liquid lithium from a lithium electrolytic cell, characterized in that the device comprises a lithium collecting device and a lithium buffer tank connected to the lithium collecting device, wherein the inlet of the lithium buffer tank is connected to the lithium electrolytic cell through the lithium collecting device to receive liquid lithium from the lithium electrolytic cell and temporarily store the liquid lithium in the lithium buffer tank, and wherein the outlet of the lithium buffer tank is connected to a lithium storage tank through a lithium discharging pipe, so that when the liquid level of the liquid lithium in the lithium buffer tank reaches a high limit, the liquid lithium in the lithium buffer tank is discharged under pressure through the lithium discharging pipe to the lithium storage tank at a low position by opening a valve provided on the lithium discharging pipe, and after discharging a certain amount of liquid lithium, the valve is closed.

[0007] Further, during the discharging of the liquid lithium, the liquid level of the liquid lithium in the lithium buffer tank is always higher than the highest point of the lithium discharging pipe, so that the liquid lithium is discharged in the form of full pipe flow through the lithium discharging pipe. Advantageously, the valve is closed after a predetermined time to obtain the certain amount of liquid lithium. Alternatively, when the liquid level of the liquid lithium in the lithium buffer tank reaches a low limit, the valve is closed to obtain the certain amount of liquid lithium.

[0008] Further, the lithium collecting device is a lithium collecting cover, which is arranged in the electrolyte in the lithium electrolytic cell and above the cathode in the lithium electrolytic cell, so that the lithium droplets generated at the cathode are collected in the lithium collecting cover and enter the lithium buffer tank along the lithium collecting cover. Advantageously, the lithium collecting cover has an outer side, an inner side, and a top between the outer side and the inner side, the lower edge of the outer side is lower than the upper end of the cathode, and the inner side surrounds the anode in the lithium electrolytic cell. More advantageously, the top has an inclined lower surface, so that the collected lithium droplets can slide along the lower surface into the lithium buffer tank.

[0009] Further, the valve is an automatically controlled or manually controlled valve. Advantageously, the valve is a stop valve or a ball valve.

[0010] Further, the inlet end and / or outlet end of the lithium discharging pipe is provided with a filtering device for filtering solid impurities in the liquid lithium.

[0011] Further, the lithium guide pipe is inserted from the top or side of the lithium buffer tank, and the inlet end of the lithium guide pipe is arranged higher than the outlet end, so that the high limit of the liquid level of the liquid lithium in the lithium buffer tank is higher than the highest point of the lithium guide pipe, and the low limit of the liquid level of the liquid lithium in the lithium buffer tank is higher than the inlet end of the lithium guide pipe. Alternatively, the lithium guide pipe is inserted from the top or side of the lithium buffer tank, and the inlet end of the lithium guide pipe is arranged lower than the outlet end, so that the high limit of the liquid level of the liquid lithium in the lithium buffer tank is higher than the highest point of the lithium guide pipe, and the low limit of the liquid level of the liquid lithium in the lithium buffer tank is higher than the outlet end of the lithium guide pipe.

[0012] Further, the lithium buffer tank is provided with a liquid level monitoring meter to monitor the changing liquid level of the liquid lithium in real time. Alternatively, the lithium buffer tank is provided with two liquid level monitoring meters to monitor the high limit and the low limit of the liquid level respectively, or provided with one liquid level monitoring meter to monitor the high limit of the liquid level. Advantageously, the liquid level monitoring meter includes a magnetic floating ball liquid level meter, an ultrasonic liquid level meter, a radar liquid level meter, and a conductive liquid level meter.

[0013] In another aspect, the present application provides a system for quantitatively guiding liquid lithium out of a lithium electrolysis tank, characterized in that the system comprises a lithium electrolysis tank, a lithium storage tank, and a device according to the present application for guiding liquid lithium out of the lithium electrolysis tank into the lithium storage tank.

[0014] Further, the lithium storage tank is mobile or fixed.

[0015] In yet another aspect, the present application provides a method for quantitatively guiding liquid lithium out of a lithium electrolysis tank using a device according to the present application, characterized in that the method comprises the following steps: continuously monitoring whether the liquid level of the liquid lithium in the lithium buffer tank reaches a high limit; when the liquid level of the liquid lithium in the lithium buffer tank reaches the high limit, guiding the liquid lithium in the lithium buffer tank out of the lithium guide pipe under pressure into the lithium storage tank at a low position by opening a valve arranged on the lithium guide pipe; and closing the valve after guiding the quantified liquid lithium.

[0016] Further, during the guiding of the liquid lithium, the liquid level of the liquid lithium in the lithium buffer tank is always higher than the highest point of the lithium guide pipe, so that the liquid lithium is guided out of the lithium guide pipe in the form of full pipe flow. Advantageously, the step of closing the valve comprises: closing the valve after the valve is opened for a predetermined guiding time to obtain the quantified liquid lithium.

[0017] Alternatively, the step of closing the valve comprises: continuously monitoring whether the liquid level of the liquid lithium in the lithium buffer tank reaches a low limit; and closing the valve to obtain the quantified liquid lithium when the liquid level of the liquid lithium in the lithium buffer tank reaches the low limit.

[0018] Further, the method further comprises the following steps to determine the mass of the extracted liquid lithium:

[0019] The mass M of the liquid lithium in the lithium buffer tank is determined from the liquid level H0 of the liquid lithium in the lithium buffer tank, the pressure P0 in the lithium buffer tank, the liquid level H1 of the electrolyte in the lithium electrolytic cell, the pressure P1 in the electrolytic chamber of the lithium electrolytic cell, the cross-sectional area S0 of the lithium buffer tank, the density p of the liquid lithium Li , the density p of the electrolyte Ba , by the following equation:

[0020] The upper limit H max and the lower limit H min of the liquid level H0 of the liquid lithium in the lithium buffer tank are set, and the mass M of the liquid lithium in the lithium buffer tank before and after the extraction of the liquid lithium is calculated by the above equation as M max and M min ;

[0021] The lithium revision coefficient M is determined from the current I in the lithium electrolytic cell, the lithium electrochemical equivalent C, the extraction time t of the liquid lithium, the current efficiency η of the lithium electrolytic cell, by the following equation: mod

[0022] M mod = C x I x t x η; and

[0023] The mass m of the extracted liquid lithium is calculated by the following equation:

[0024] m = M max - M min + M mod .

[0025] Alternatively, the method further comprises the following steps to determine the mass of the extracted liquid lithium:

[0026] The upper limit H max of the liquid level of the liquid lithium in the lithium buffer tank is located, and the lower limit H min of the liquid level of the liquid lithium in the lithium buffer tank is set; and

[0027] The mass m of the extracted liquid lithium is calculated by the following equation:

[0028] The beneficial effects of the present application are: by monitoring the liquid level in the lithium buffer tank (for example, by the liquid level monitor arranged in the lithium buffer tank), the valve on the lithium guide pipe is opened when the liquid level reaches the guide-out height, and by monitoring the height of the liquid level drop or monitoring the guide-out time during the guide-out process, the purpose of guiding out a quantitative liquid lithium can be achieved. In addition, the lithium liquid level in the lithium buffer tank during the lithium guide-out process is always higher than the highest point of the lithium guide pipe, so that the lithium liquid in the lithium guide pipe is always in a full pipe state and can automatically flow out, avoiding the reaction of metal lithium with air during the guide-out process, which produces lithium oxides, nitrides and electrolytes to block the lithium guide pipe. The present application has strong implementability and can achieve the purpose of automatic quantitative lithium output with adjustable lithium output capacity or mass, effectively improving the automation and intelligent level of lithium electrolysis production. BRIEF DESCRIPTION OF DRAWINGS

[0029] Fig. 1 is a structural schematic diagram of a system for quantitatively guiding out liquid metal lithium from a lithium electrolysis tank in embodiment 1 of the present application;

[0030] Fig. 2 is a structural schematic diagram of a system for quantitatively guiding out liquid metal lithium from a lithium electrolysis tank in embodiment 2 of the present application.

[0031] The list of reference numerals in the drawings: 1, lithium electrolysis tank; 2, cathode; 3, anode; 4, lithium collection cover; 5, lithium buffer tank; 6, liquid level monitor; 7, lithium guide pipe; 8, valve; 9, filtering device; 10, lithium storage tank; 11, air inlet pipe; 12, lithium outlet pipe. DETAILED DESCRIPTION

[0032] In order to better explain the present application and facilitate understanding, the present application is described in detail below through specific embodiments in combination with the drawings.

[0033] The present application provides a device, system and method for quantitatively discharging liquid lithium from a lithium electrolysis cell 1, wherein the device for quantitatively discharging liquid lithium from a lithium electrolysis cell 1 comprises a lithium collecting device and a lithium buffer tank 5 connected to the lithium collecting device. The lithium collecting device can be a lithium collecting hood 4, and the lithium buffer tank 5 is used to temporarily store the generated liquid lithium. The outlet of the lithium buffer tank 5 is connected to a lithium storage tank 10 through a lithium guide pipe 7, and the lithium storage tank 10 is used to store the liquid lithium discharged from the lithium buffer tank 5. The lower part or bottom of the lithium buffer tank 5 is provided with an inlet connected to the lithium electrolysis cell 1 through the lithium collecting hood 4. A liquid level monitor 6 is arranged in the lithium buffer tank 5 to monitor the liquid level of the lithium in the lithium buffer tank 5. Specifically, the liquid level monitor 6 includes but is not limited to a magnetic floating ball liquid level meter, an ultrasonic liquid level meter, a radar liquid level meter, a conductive liquid level meter, etc. Specifically, one liquid level monitor can be arranged in the lithium buffer tank 5 to monitor the height of the liquid level in real time, or two liquid level monitors can be arranged to monitor the high limit and low limit of the liquid level respectively, or one liquid level monitor can be arranged to monitor the high limit of the liquid level. A valve 8 is arranged on the lithium guide pipe 7. Specifically, the valve 8 on the lithium guide pipe 7 can be automatically controlled or manually controlled. The valve 8 includes but is not limited to a stop valve, a ball valve, etc. The lithium buffer tank 5, the lithium guide pipe 7, the valve 8 and the lithium storage tank 10 are partially or entirely provided with heating and insulation functions.

[0034] The lithium buffer tank 5 monitors the height of the liquid level through the liquid level monitor 6, and when the lithium liquid level in the lithium buffer tank 5 reaches the high limit, the valve 8 on the lithium guide pipe 7 is opened. The liquid lithium flows into the lithium storage tank 10 at a low position in the form of full pipe flow under the action of pressure, and the valve 8 is closed after a certain amount of liquid lithium is discharged. The liquid level of the lithium in the lithium buffer tank 5 is always higher than the highest point of the lithium guide pipe 7 during the discharge of the liquid lithium. Specifically, the lithium guide pipe 7 is inserted from the top or side of the lithium buffer tank 5, and the inlet end of the lithium guide pipe 7 is higher than the outlet end, so that when the valve 8 is opened, the high limit position of the lithium liquid level in the lithium buffer tank 5 is higher than the highest point of the lithium guide pipe 7, and when the valve 8 is closed, the height of the low limit position of the lithium liquid level in the lithium buffer tank 5 is higher than the inlet end of the lithium guide pipe 7. Alternatively, the lithium guide pipe 7 is inserted from the top or side of the lithium buffer tank 5, and the inlet end of the lithium guide pipe 7 is lower than the outlet end, so that when the valve 8 is opened, the high limit position of the lithium liquid level in the lithium buffer tank 5 is higher than the highest point of the lithium guide pipe 7, and the low limit position of the lithium liquid level in the lithium buffer tank 5 is higher than the outlet end of the lithium guide pipe 7. The inlet end and / or outlet end of the lithium guide pipe 7 can be provided with a filtering device 9 for filtering solid impurities in the liquid lithium. The lithium storage tank 10 can be mobile, so that when the liquid lithium in the lithium storage tank 10 reaches the required weight, it can be transported to the casting or other processes. The lithium storage tank 10 can also be fixed, so that when the liquid lithium in the lithium storage tank 10 reaches the required weight, the lithium can be transported to the casting or other processes through the positive pressure or negative pressure pipeline.

[0035] Example 1

[0036] The present embodiment provides a device and system for quantitatively deriving liquid lithium from a lithium electrolytic cell. As shown in Fig. 1, the system comprises a lithium electrolytic cell 1 for electrolyzing an electrolyte to produce liquid lithium, a lithium buffer tank 5 for receiving and temporarily storing the liquid lithium from the lithium electrolytic cell 1, and a lithium storage tank 10 for receiving the liquid lithium from the lithium buffer tank 5. As shown, the lithium buffer tank 5 is partially disposed in the lithium electrolytic cell 1, and its lower part is partially immersed in the electrolyte in the lithium electrolytic cell 1. It is envisaged that the lithium buffer tank 5 can be disposed outside the lithium electrolytic cell 1, for example at a side of the lithium electrolytic cell 1, and connected to the lithium electrolytic cell 1 through a lithium collection hood 4. The lithium electrolytic cell 1 comprises a lithium electrolytic cell body, in which a cathode 2 and an anode 3 are disposed. The lithium collection hood 4 is disposed above the cathode 2 for allowing the lithium produced at the cathode 2 to enter the lithium buffer tank 5 along the lithium collection hood 4. For this purpose, the lithium collection hood 4 is disposed in the electrolyte in the lithium electrolytic cell 1 and above the cathode 2, so that the liquid lithium droplets produced at the cathode 2 float up and are collected in the lithium collection hood 4 and enter the lithium buffer tank 5 along the lithium collection hood 4. In particular, the lithium collection hood 4 has a substantially annular groove shape, and has an outer side, an inner side, and a top part between the outer side and the inner side. The lower edge of the outer side is lower than the upper edge of the cathode 2, and the inner side surrounds the central anode 3 and is inserted between the cathode 2 and the anode 3. In order to facilitate the liquid lithium accumulated on the lower surface of the top part of the lithium collection hood 4 to rise and enter the lithium buffer tank 5, the lower surface is inclined towards the upper lithium outlet end. The anode 3 passes through the inside of the lithium collection hood and does not contact the lithium collection hood. The device for quantitatively deriving liquid lithium from the lithium electrolytic cell comprises the lithium collection hood 4 and the lithium buffer tank 5 connected to the lithium collection hood 4. The device further comprises a liquid level monitoring meter 6, a lithium guide pipe 7, a valve 8, and a filtering device 9. As shown, the inlet end of the lithium guide pipe 7 extends into the lithium buffer tank 5. In particular, the lithium buffer tank 5 is an elliptical bottom-sealed tank, and the upper lithium outlet end of the lithium collection hood 4 is connected to the lithium buffer tank 5 in a welded manner. The liquid lithium droplets produced at the cathode 2 float up into the lithium collection hood 4 and slide along the lower surface of the top part of the lithium collection hood into the lithium buffer tank 5, so that the liquid level of the lithium in the lithium buffer tank 5 continuously rises.

[0037] The lithium buffer tank 5 is equipped with a level gauge 6, which in this embodiment is a hydrostatic level gauge to monitor the liquid level in real time. When the level gauge 6 detects that the lithium metal level has risen to the high limit, the valve 8 automatically opens, and the lithium metal flows into the lithium storage tank 10 located at the low level under pressure. When the level gauge 6 detects that the lithium metal level has dropped to the low limit, the valve 8 automatically closes, stopping the lithium discharge. During the lithium metal discharge process, the lithium level is always higher than the highest point of the lithium guide tube, and the lithium liquid in the lithium guide tube is fully flowing. The lithium metal in the lithium guide tube 7 flows into the filter device 9 located inside the lithium storage tank 10, and the lithium liquid that has been filtered to remove impurities enters the lithium storage tank 10. The lithium storage tank 10 is transported to the casting process by an overhead crane or a transfer trolley, where the lithium liquid is poured out for casting.

[0038] The following describes a method for quantitatively exporting liquid lithium from a lithium-ion electrolyzer using the apparatus of this embodiment. During the process of generating liquid lithium in the lithium-ion electrolyzer 1 and allowing it to enter the lithium buffer tank 5, a level gauge 6 continuously monitors whether the liquid lithium level in the lithium buffer tank 5 reaches a high limit. When the level reaches the high limit, valve 8 is opened to begin exporting the liquid lithium from the lithium buffer tank 5. After exporting a measured amount of liquid lithium, valve 8 is closed. Specifically, during the export process, the level gauge 6 continuously monitors whether the liquid lithium level in the lithium buffer tank 5 reaches a low limit, and valve 8 is closed when the level reaches the low limit.

[0039] The mass of liquid lithium metal derived in this way can be calculated as follows.

[0040] First, based on the liquid lithium level H0 in the lithium buffer tank, the pressure P0 in the lithium buffer tank, the electrolyte level H1, the pressure P1 in the electrolysis chamber of the lithium electrolyzer, the cross-sectional area S0 of the lithium buffer tank, and the density ρ of liquid lithium... Li The density ρ of electrolytes Ba The mass M of liquid lithium metal in the lithium buffer tank is determined by the following formula:

[0041] Next, set the upper limit H0 of the liquid lithium level H0 in the lithium buffer tank. max and lower limit H min The mass M of lithium in the lithium buffer tank before and after the export of liquid lithium metal can be calculated using the above formula. max and M min ;

[0042] Then, based on the current I in the lithium electrolyzer, the lithium electrochemical equivalent C, the extraction time t of liquid lithium metal, and the current efficiency η of the electrolyzer, the lithium revision factor M is determined by the following formula. mod M mod =C×I×t×η.

[0043] Finally, based on the calculated M maxM min and M mod The mass m of the derived liquid lithium is calculated from the following formula: m = M max -M min + M mod .

[0044] As an example, in the present embodiment, when the lithium level in the lithium buffer tank reaches the upper limit: the upper limit H max = 2.5 m of the lithium level H0, the pressure P0 in the lithium buffer tank = 1.013 x 10 5 Pa, the level H1 of the electrolyte = 1.8 m, the pressure P1 in the electrolytic chamber = 1.003 x 10 5 Pa, the cross-sectional area S0 of the lithium buffer tank = 0.01766 m 2 , the density p Li = 500 kg / m 3 of the lithium liquid, and the density p Ba = 1500 kg / m 3 of the electrolyte, then the mass M max = 10.16 kg of the liquid lithium before derivation.

[0045] As an example, in the present embodiment, when the lithium level in the lithium buffer tank reaches the lower limit: the lower limit H min = 2.2 m of the lithium level H0, the pressure P0 in the lithium buffer tank = 1.013 x 10 5 Pa, the level H1 of the electrolyte = 1.7 m, the pressure P1 in the electrolytic chamber = 1.003 x 10 5 Pa, the cross-sectional area S0 of the lithium buffer tank = 0.01766 m 2 , the density p Li = 500 kg / m 3 of the lithium liquid, and the density p Ba = 1500 kg / m 3 of the electrolyte, then the mass M min = 7.50 kg of the liquid lithium after derivation.

[0046] In the present embodiment, the lithium electrochemical equivalent C = 0.259 g / A / h, the current I in the lithium electrolytic cell = 30000 A, the derivation time t of the liquid metal lithium = 7 s, and the current efficiency η of the lithium electrolytic cell = 85%, then the lithium revision coefficient M mod = 0.0128 kg. In the present embodiment, the amount of lithium is quantified as m = M max - M min + M mod = 2.67 kg.

[0047] Embodiment 2

[0048] The present embodiment provides a device and system for quantitatively discharging liquid lithium from a lithium electrolysis cell. As shown in Fig. 2, the system comprises a lithium electrolysis cell 1, a lithium buffer tank 5, and a lithium storage tank 10. The device for quantitatively discharging liquid lithium from the lithium electrolysis cell comprises a lithium collection hood 4 and the lithium buffer tank 5 connected to the lithium collection hood 4. The device further comprises a liquid level monitoring meter 6, a lithium discharge pipe 7, a valve 8, and a filter device 9. The lithium storage tank 10 is provided with an air inlet pipe 11 and a lithium outlet pipe 12. As shown, the inlet end of the lithium discharge pipe 7 is located at the side wall of the lithium buffer tank 5. In order to facilitate the disassembly and maintenance of the lithium buffer tank 5, the lithium buffer tank 5 is a round-bottomed open tank, and the upper end of the lithium collection hood 4 is inserted into the lithium buffer tank 5. The liquid level monitoring meter 6 is a conductive liquid level meter that monitors the upper limit of the liquid level.

[0049] The method for discharging liquid lithium from the lithium electrolysis cell using the device of the present embodiment is basically the same as the method of Embodiment 1. The difference is that, in the present embodiment, the lower limit of the liquid level of the liquid lithium in the lithium buffer tank 5 is not monitored during the discharging process, but the valve 8 is closed after a predetermined discharging time.

[0050] The mass of the liquid lithium discharged in this way can be calculated as follows. First, the upper limit H max of the liquid level of the lithium in the lithium buffer tank 5 is located using the liquid level monitoring meter 6, and the lower limit H min of the liquid level of the lithium in the lithium buffer tank 5 is set. Then, the mass m of the liquid lithium discharged is calculated according to the discharging time t, the cross-sectional area S of the lithium discharge pipe 7, and the following formula:

[0051] As an example, in the present embodiment, the upper limit H max of the liquid level of the lithium is 30 cm, the cross-sectional area S of the lithium discharge pipe 7 is 0.000314 m 2 , and the discharging time t is 49 s, then the mass m of the liquid lithium discharged is 14.148 kg.

[0052] In the present embodiment, the lithium storage tank 10 is not movable, and the air inlet pipe 11 and the lithium outlet pipe 12 are arranged thereon, and the lithium is transported to the casting or other processes by means of positive pressure pipeline transportation. Other features are the same as those of Embodiment 1.

[0053] The above examples provide some ways to calculate the mass of the liquid lithium discharged. Those skilled in the art will realize that the mass of the discharged liquid lithium can be obtained in other ways. For example, the mass of the discharged liquid lithium can be obtained from a mapping diagram or a lookup table, which reflects the correspondence between the mass of the discharged liquid lithium and the liquid level in the lithium buffer tank, the liquid level in the lithium storage tank, or the discharging time. These mapping diagrams or lookup tables can be obtained or calibrated from calculation or actual production processes, and can be used for manual control of the valve, or can be stored in a memory for automatic control of the valve.

[0054] Although the embodiments of the present application have been shown and described above, it is understood that the above embodiments are exemplary and are not to be construed as limiting the present application. Each technical feature of the above embodiments can be arbitrarily combined, as long as the combination of the technical features does not result in a contradiction, and it should be considered that the combination is within the scope of the present disclosure. Any modification, modification, replacement and variation of the above embodiments made by those skilled in the art are within the scope of the present application.

Claims

1. A device for quantitatively extracting liquid lithium from a lithium electrolyzer, characterized in that, The apparatus includes a lithium collection device and a lithium buffer tank connected to the lithium collection device. The inlet of the lithium buffer tank is connected to the lithium electrolyzer through the lithium collection device to receive liquid lithium from the lithium electrolyzer and temporarily store the liquid lithium in the lithium buffer tank. The outlet of the lithium buffer tank is connected to a lithium storage tank through a lithium guide pipe. When the liquid lithium level in the lithium buffer tank reaches the high limit, a valve provided on the lithium guide pipe is opened to allow the liquid lithium in the lithium buffer tank to be discharged under pressure through the lithium guide pipe to the lithium storage tank located at the lower level. After a certain amount of liquid lithium is discharged, the valve is closed.

2. The apparatus according to claim 1, characterized in that, During the process of exporting liquid lithium, the liquid lithium level in the lithium buffer tank is always higher than the highest point of the lithium guide tube, so that the liquid lithium is exported in the form of full-pipe flow through the lithium guide tube.

3. The apparatus according to claim 2, characterized in that, The valve is closed after being opened for a predetermined time to obtain the specified amount of liquid lithium.

4. The apparatus according to claim 1, characterized in that, When the liquid lithium level in the lithium buffer tank reaches the low limit, the valve is closed to obtain the measured amount of liquid lithium.

5. The apparatus according to claim 1, characterized in that, The lithium collection device is a lithium collection hood, which is disposed in the electrolyte in the lithium electrolyzer and located above the cathode in the lithium electrolyzer, so that lithium droplets generated at the cathode are collected in the lithium collection hood and enter the lithium buffer tank along the lithium collection hood.

6. The apparatus according to claim 5, characterized in that, The lithium collection hood has an outer side, an inner side, and a top located between the outer side and the inner side. The lower edge of the outer side is lower than the upper end of the cathode. The inner side surrounds the anode in the lithium electrolyzer. The top has an inclined lower surface, allowing collected lithium droplets to slide along the lower surface into the lithium buffer tank.

7. The apparatus according to claim 1, characterized in that, The inlet and / or outlet of the lithium-conducting tube are equipped with a filter device for filtering solid impurities in liquid lithium.

8. A system for quantitatively extracting liquid lithium from a lithium electrolyzer, characterized in that, The system includes a lithium electrolyzer, a lithium storage tank, and an apparatus according to any one of claims 1 to 7, the apparatus being used to export liquid lithium from the lithium electrolyzer to the lithium storage tank.

9. The system according to claim 8, characterized in that, The lithium storage tank can be mobile or stationary.

10. A method for quantitatively extracting liquid lithium from a lithium electrolyzer using the apparatus according to any one of claims 1 to 7, characterized in that, The method includes the following steps: Continuously monitor whether the liquid lithium level in the lithium buffer tank reaches the high limit. When the liquid lithium level in the lithium buffer tank reaches the high limit, the valve on the lithium guide pipe is opened, allowing the liquid lithium in the lithium buffer tank to be discharged under pressure through the lithium guide pipe to the lithium storage tank located at the lower level; and After discharging a measured amount of liquid lithium, close the valve.

11. The method according to claim 10, characterized in that, During the process of exporting liquid lithium, the liquid lithium level in the lithium buffer tank is always higher than the highest point of the lithium guide tube, so that the liquid lithium is exported in the form of full-pipe flow through the lithium guide tube.

12. The method according to claim 11, characterized in that, The step of closing the valve includes: closing the valve after a predetermined outlet time has elapsed since the valve was opened to obtain the measured amount of liquid lithium.

13. The method according to claim 10, characterized in that, The steps to close the valve include: Continuously monitor whether the liquid lithium level in the lithium buffer tank has reached the low limit. When the liquid lithium level in the lithium buffer tank reaches the lower limit, the valve is closed to obtain the measured amount of liquid lithium.

14. The method according to claim 13, characterized in that, The method further includes the following steps to determine the mass of the exported liquid lithium: Based on the liquid lithium level H0 in the lithium buffer tank, the pressure P0 in the lithium buffer tank, the electrolyte level H1 in the lithium electrolyzer, and the pressure P in the electrolysis chamber of the lithium electrolyzer... l The cross-sectional area S0 of the lithium buffer tank and the density ρ of liquid lithium. Li The density ρ of electrolytes Ba The mass M of liquid lithium in the lithium buffer tank is determined by the following formula. The upper limit H of the liquid lithium level H0 in the lithium buffer tank is set. max and lower limit H min The mass M of liquid lithium in the lithium buffer tank before and after the discharge of liquid lithium is calculated using the above formula. max and M min ; The lithium revision factor M is determined by the following formula based on the current I in the lithium electrolyzer, the lithium electrochemical equivalent C, the liquid lithium extraction time t, and the current efficiency η of the lithium electrolyzer. mod M mod =C×I×t×η; and The mass m of the derived liquid lithium is calculated using the following formula. m=M max -M min +M mod 。 15. The method according to claim 12, characterized in that, The method further includes the following steps to determine the mass of the exported liquid lithium: The upper limit H of the liquid lithium level in the lithium buffer tank is located. max And set a lower limit H for the liquid lithium level in the lithium buffer tank. min ;and Based on the liquid lithium extraction time t and the cross-sectional area S of the lithium-conducting tube, the mass m of the extracted liquid lithium is calculated using the following formula.

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