Device and method for quantitative discharge of liquid lithium from a lithium electrolytic cell

Abstract

A device and method for quantitatively leading out liquid lithium from a lithium electrolytic cell, relating to the technical field of lithium electrolytic cell, comprising a lithium buffer tank connected with a lithium collecting device, the lithium outlet end of the lithium buffer tank is connected with a lithium storage tank through a lithium leading pipe, a liquid level monitoring gauge is arranged in the lithium buffer tank, a valve is arranged on the lithium leading pipe, the lithium buffer tank monitors the height of the liquid level through the liquid level monitoring gauge, when the lithium liquid level in the lithium buffer tank reaches the high limit, the valve on the lithium leading pipe is opened, the liquid metal lithium flows into the lithium storage tank at low position in the form of full pipe flow under the action of pressure, the valve is closed after the quantitative liquid metal lithium is led out, and the lithium liquid level in the lithium buffer tank is always higher than the highest point of the lithium leading pipe during the process of leading out the liquid metal lithium. The present application realizes automatic, quantitative and safe transfer of the liquid metal lithium in the cell, avoids secondary pollution in the process of leading out the lithium, and reduces the maintenance difficulty of the system and the labor intensity of the workers.

Description

Technical Field

[0001] This invention relates to the field of lithium electrolyzer technology, and in particular to an apparatus and method for quantitatively exporting liquid lithium metal from a lithium electrolyzer. Background Technology

[0002] In the current lithium metal electrolysis industry, the extraction of molten lithium produced in the tank often requires workers to use tools to scoop it out and cast it into crude lithium ingots. This operation involves significant labor intensity and safety risks. Furthermore, the lithium metal will come into contact with air, causing secondary oxidation, which leads to a decrease in metal purity, reduced current efficiency, and increased production costs.

[0003] Chinese patent application CN220685268 U discloses an automatic lithium electrolyzer, in which lithium extraction is achieved by enriching the lithium metal in the electrolyzer using a lithium collecting device and overflowing the lithium liquid through a flow guiding device. However, the amount of lithium extracted during the extraction process is difficult to control, and as the working time increases, some lithium metal or lithium oxide remains in the overflow pipe, affecting the extraction efficiency. Chinese patent application CN220685267 U discloses an automatic lithium extraction device for a lithium electrolyzer, which collects lithium metal through a lithium collecting furnace connected to the lithium discharge pipe of the electrolyzer. The collecting furnace has a built-in three-stage siphon flow guiding component to guide the lithium metal flow, but it still suffers from the problems of difficult maintenance of the lithium discharge pipe and a complex internal structure of the collecting furnace.

[0004] Given the numerous drawbacks of the lithium electrolysis cell lithium extraction devices mentioned above, and considering the requirements for automation, precision, safety, and environmental protection in the lithium electrolysis production field, how to enable the automatic, quantitative, and safe transfer of liquid lithium metal, while reducing the workload of replacement and maintenance during system operation, is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a device and method for quantitatively exporting liquid lithium metal from a lithium electrolysis cell. The purpose is to realize the automatic, quantitative and safe transfer of lithium metal in the cell, avoid secondary pollution during the lithium extraction process, and reduce the maintenance difficulty of the system and the labor intensity of workers.

[0006] To achieve the above objectives, the main technical solutions adopted by the present invention include:

[0007] A device for quantitatively exporting liquid lithium metal from a lithium electrolyzer includes a lithium buffer tank connected to a lithium collection device. The lithium outlet of the lithium buffer tank is connected to a lithium storage tank via a lithium guide tube. The lithium buffer tank is equipped with a level gauge, and the lithium guide tube is equipped with a valve. The lithium buffer tank monitors the liquid level using the level gauge. When the lithium level in the lithium buffer tank reaches the high limit, the valve on the lithium guide tube is opened. Under pressure, the liquid lithium metal flows through the lithium guide tube into the lower-level lithium storage tank in a full-pipe flow. After exporting a fixed amount of liquid lithium metal, the valve is closed. During the lithium metal export process, the lithium level in the lithium buffer tank is always higher than the highest point of the lithium guide tube.

[0008] Furthermore, the liquid level monitoring instrument includes a magnetic levitation ball liquid level gauge, an ultrasonic liquid level gauge, a radar liquid level gauge, and a conductive liquid level gauge.

[0009] Furthermore, the valves on the lithium conductor include automatic control and manual control, and the valves include shut-off valves and ball valves.

[0010] Furthermore, the beginning and / or end of the lithium-conducting tube are provided with a filter device for filtering solid impurities in the liquid lithium metal.

[0011] Furthermore, the lithium guide tube is inserted from the top or side of the lithium buffer tank, with the beginning of the lithium guide tube higher than the end. The position of the high limit of the lithium liquid level in the lithium buffer tank is higher than the highest point of the lithium guide tube, and the height of the low limit of the lithium liquid level in the lithium buffer tank is higher than the beginning of the lithium guide tube.

[0012] Furthermore, the lithium guide tube is inserted from the top or side of the lithium buffer tank, with the beginning of the lithium guide tube lower than the end, the high limit position of the lithium liquid level in the lithium buffer tank higher than the highest point of the lithium guide tube, and the low limit position of the lithium liquid level in the lithium buffer tank higher than the end of the lithium guide tube.

[0013] Furthermore, the lithium buffer tank is equipped with a liquid level monitor to monitor the liquid level in real time, or two liquid level monitors are equipped to monitor the high limit and low limit of the liquid level respectively, or a liquid level monitor is equipped to monitor the high limit of the liquid level.

[0014] Furthermore, the lithium storage tank can be either mobile or stationary.

[0015] The liquid lithium metal extraction method using the aforementioned device, when employing a single level gauge to monitor the liquid level in real time, or using two level gauges to monitor the high and low limits of the liquid level respectively, includes the following steps:

[0016] Step S01: Based on the lithium liquid level height H 0 Internal pressure of lithium buffer tank P 0 Electrolyte liquid level H 1 Electrolysis chamber pressureP 1 Cross-sectional area of ​​lithium buffer can S 0 Lithium liquid density r Li Electrolyte density r Ba Determine the mass of liquid lithium metal in the lithium buffer tank. M ;

[0017]

[0018] Step S02: Set the high limit of lithium liquid level in the lithium buffer tank. H max and lithium liquid level low limit H min The mass of lithium in the lithium buffer tank before and after exporting liquid lithium metal M max and M min ;

[0019] Step S03: Based on the electrolytic cell current I Lithium-ion battery chemical equivalent C Time to extract liquid lithium metal t Electrolytic cell current efficiency or The characteristics determine the lithium revision factor M mod Calculate and derive the mass of liquid lithium metal m ;

[0020] .

[0021] The liquid lithium metal extraction method using the aforementioned device, when employing a level gauge to monitor the high limit of the liquid level, includes the following steps:

[0022] Step S1: The level monitoring gauge locates the high limit of the lithium liquid level in the lithium buffer tank. H max Set the lower limit of the lithium level in the lithium buffer tank. H min ;

[0023] Step S2: Based on the time of exporting liquid lithium metal t Cross-sectional area of ​​lithium conduction diode S Calculate and derive the mass of liquid lithium metal m ;

[0024] .

[0025] The beneficial effects of this invention are as follows: By installing a level monitor inside the lithium buffer tank and a valve on the lithium-conducting tube, the liquid level is monitored to ensure that the lithium level in the buffer tank remains higher than the highest point of the lithium-conducting tube during the lithium metal extraction process. This ensures that the lithium-conducting tube is always full and can flow out automatically, preventing the lithium metal from reacting with air during extraction and producing lithium oxides, nitrides, and electrolytes that could clog the tube. This invention is highly feasible and can achieve automatic quantitative lithium extraction with adjustable capacity or quality, effectively improving the automation and intelligence level of lithium electrolysis production. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the device for quantitatively exporting liquid lithium metal from a lithium electrolyzer in Embodiment 1 of the present invention;

[0027] Figure 2 This is a schematic diagram of the device structure for quantitatively exporting liquid lithium metal from a lithium electrolyzer in Embodiment 2 of the present invention.

[0028] In the diagram: 1 is the lithium electrolytic cell; 2 is the cathode; 3 is the anode; 4 is the lithium collection hood; 5 is the lithium buffer tank; 6 is the liquid level gauge; 7 is the lithium guide tube; 8 is the valve; 9 is the filter device; 10 is the lithium storage tank; 11 is the air inlet pipe; 12 is the lithium outlet pipe. Detailed Implementation

[0029] To better explain and facilitate understanding of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0030] This invention provides an apparatus and method for quantitatively exporting liquid lithium metal from a lithium electrolyzer. The apparatus includes a lithium buffer tank 5 connected to a lithium collection device, which may be a lithium collection hood 4. The lithium buffer tank 5 is used to buffer the generated liquid lithium metal. The lithium outlet of the lithium buffer tank 5 is connected to a lithium storage tank 10 via a lithium guide pipe 7. The lithium storage tank 10 is used to store the liquid lithium metal exported from the lithium buffer tank 5. A level gauge 6 is provided inside the lithium buffer tank 5 to monitor the liquid lithium level. Specifically, the level gauge 6 includes, but is not limited to, a magnetic levitation level gauge, an ultrasonic level gauge, a radar level gauge, and a conductive level gauge. Specifically, the lithium buffer tank 5 can be equipped with one level gauge to monitor the liquid level in real time, or two level gauges can be equipped to monitor the high and low limits of the liquid level respectively, or a single level gauge can be used to monitor the high limit of the liquid level. The lithium-conducting tube 7 is equipped with a valve 8. Specifically, the valve 8 on the lithium-conducting tube 7 can be automatically controlled or manually controlled. The valve 8 includes, but is not limited to, a shut-off valve and a ball valve. The lithium buffer tank 5, the lithium-conducting tube 7, the valve 8, and the lithium storage tank 10 have heating and heat preservation functions in some or all of them.

[0031] The lithium buffer tank 5 monitors the lithium level using a level gauge 6. When the lithium level in the buffer tank 5 reaches the high limit, the valve 8 on the lithium guide tube 7 is opened. Under pressure, the lithium metal flows through the lithium guide tube 7 into the lower-level lithium storage tank 10 in a full-pipe flow. After a certain amount of lithium metal is discharged, the valve 8 is closed. During the lithium metal discharge process, the lithium level in the buffer tank 5 remains higher than the highest point of the lithium guide tube 7. Specifically, the lithium guide tube 7 is inserted from the top or side of the buffer tank 5, with its beginning higher than its end. The high limit of the lithium level in the buffer tank 5 is higher than the highest point of the lithium guide tube 7, and the low limit of the lithium level in the buffer tank 5 is higher than the beginning of the lithium guide tube 7. Alternatively, the lithium guide tube 7 is inserted from the top or side of the buffer tank 5, with its beginning lower than its end. The high limit of the lithium level in the buffer tank 5 is higher than the highest point of the lithium guide tube 7, and the low limit of the lithium level in the buffer tank 5 is higher than the end of the lithium guide tube 7. Specifically, the beginning and / or end of the lithium-conducting pipe 7 are equipped with a filter device 9 for filtering solid impurities in the molten lithium metal. The lithium storage tank 10 can be mobile, transported to casting or other processes after the liquid lithium metal in the storage tank 10 reaches the required weight. The lithium storage tank 10 can also be stationary, transported to casting or other processes via positive or negative pressure pipelines after the liquid lithium metal in the storage tank 10 reaches the required weight.

[0032] Example 1

[0033] This embodiment provides a device for quantitatively exporting liquid lithium metal from a lithium electrolyzer, such as... Figure 1 As shown, the lithium electrolyzer includes a lithium electrolyzer body 1, within which a cathode 2 and an anode 3 are disposed. A lithium collection hood 4 is positioned above the cathode 2 to allow the generated lithium to enter a lithium buffer tank 5 along the lithium collection hood 4. The lower outer edge of the lithium collection hood 4 is located below the upper edge of the cathode 3 in the electrolyzer, and the inner side of the lithium collection hood 4 is inserted between the cathode and anode. The upper surface of the lithium collection hood 4 is inclined, and the anode 3 passes through the inside of the lithium collection hood without contacting it. The device for quantitatively exporting liquid metallic lithium from the lithium electrolyzer includes a lithium buffer tank 5, a level gauge 6, a lithium guide tube 7, a lithium valve 8, a filter device 9, and a lithium storage tank 10. Specifically, the lithium buffer tank 5 is an elliptical, sealed-bottom can. The upper lithium outlet end of the lithium collection hood 4 is welded to the lithium buffer tank 5. Lithium droplets generated by the cathode 2 float to the lithium collection hood 4 and slide down the top of the lithium collection hood into the lithium buffer tank 5, causing the lithium level in the lithium buffer tank 5 to continuously rise.

[0034] The lithium buffer tank 5 is equipped with a level gauge 6. In this embodiment, the level gauge 6 is a hydrostatic level gauge that monitors 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.

[0035] The method for calculating the mass of liquid lithium metal exported in this study is as follows:

[0036] Step S01: Based on the lithium liquid level height H 0 Internal pressure of lithium buffer tank P 0 Electrolyte liquid level H 1 Electrolysis chamber pressure P 1 Cross-sectional area of ​​lithium buffer tank S 0 Lithium liquid density r Li Electrolyte density r Ba Determine the mass of liquid lithium metal in the lithium buffer tank. M ;

[0037]

[0038] Step S02: Set the high limit of lithium liquid level in the lithium buffer tank. H max and lithium liquid level low limit H min The mass of lithium in the lithium buffer tank before and after exporting liquid lithium metal M max and M min ;

[0039] Step S03: Based on the electrolytic cell current I Lithium-ion battery chemical equivalent C Time to extract liquid lithium metal t Electrolytic cell current efficiency or The characteristics determine the lithium revision factor M mod Calculate and derive the mass of liquid lithium metal m ;

[0040] .

[0041] In this embodiment, when the lithium level in the lithium buffer tank reaches the high limit:

[0042] Lithium liquid level height H O=2.5m, lithium buffer tank pressure P 0 = 1.013 × 10 5 Pa, electrolyte level H 1=1.8m, Electrolysis chamber pressure P 1 = 1.003 × 10 5 Pa, cross-sectional area of ​​lithium buffer can S 0 = 0.01766m 2 Lithium liquid density r Li =500kg / m 3 Electrolyte density r Ba =1500kg / m 3 , M max =10.16kg.

[0043] In this embodiment, when the lithium level in the lithium buffer tank reaches the low limit:

[0044] Lithium liquid level height H O=2.2m, lithium buffer tank pressure P 0 = 1.013 × 10 5 Pa, electrolyte level H 1=1.7m, Electrolysis chamber pressure P 1 = 1.003 × 10 5 Pa, cross-sectional area of ​​lithium buffer tank S 0 = 0.01766m 2 Lithium liquid density r Li =500kg / m 3 Electrolyte density r Ba =1500kg / m 3 , M min =7.50kg.

[0045] In this embodiment, the lithium electrochemical equivalent C = 0.259 g / A / h, the electrolytic cell current I = 30000 A, and the time for extracting liquid lithium metal is... t =7s, electrolytic cell current efficiency or =85%, then the lithium revision factor M mod =0.0128 kg. In this embodiment, the quantitative lithium output is... m=M max - M min + M mod =2.67 kg.

[0046] Example 2

[0047] This embodiment provides a device for quantitatively exporting liquid lithium metal from a lithium electrolyzer, such as... Figure 2 As shown, the device for quantitatively exporting liquid lithium metal from the lithium electrolysis cell includes a lithium buffer tank 5, a level gauge 6, a lithium guide tube 7, a valve 8, a filter device 9, a lithium storage tank 10, an air inlet pipe 11, and a lithium outlet pipe 12. To facilitate disassembly and maintenance of the lithium buffer tank 5, it is a round, open-bottomed tank, with the upper end of the lithium collection cover 4 inserted into it. The level gauge 6 is a conductive level gauge that monitors the upper limit of the liquid level. The method for exporting liquid lithium metal is as follows:

[0048] Step S1: The level monitoring gauge locates the high limit of the lithium liquid level in the lithium buffer tank. H max Set the lower limit of the lithium level in the lithium buffer tank. H min ;

[0049] Step S2: Based on the time of exporting liquid lithium metal t Cross-sectional area of ​​lithium-ion transistor S Calculate and derive the mass of liquid lithium metal m ;

[0050] .

[0051] In this embodiment H max =30cm, cross-sectional area of ​​lithium conductive tube S =0.000314m 2 The extraction time was 49 seconds, and the mass of liquid lithium metal extracted was 14.148 kg.

[0052] The lithium storage tank 10 is immovable and is equipped with an air inlet pipe 11 and a lithium outlet pipe 12. Lithium is transported to casting or other processes via a positive pressure pipeline. Other aspects are the same as in Example 1.

[0053] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Any modifications, alterations, substitutions, and variations made by those skilled in the art to the above embodiments are within the scope of the present invention.

Claims

1. A device for quantitatively exporting liquid metallic lithium from a lithium electrolyzer, characterized in that: The system includes a lithium buffer tank connected to a lithium collection device. The lithium outlet of the lithium buffer tank is connected to a lithium storage tank via a lithium guide tube. The lithium buffer tank is equipped with a level gauge, and the lithium guide tube has a valve. The lithium buffer tank monitors the lithium level using the level gauge. When the lithium level in the lithium buffer tank reaches the high limit, the valve on the lithium guide tube is opened. Under pressure, the lithium metal flows through the lithium guide tube in a full-pipe flow into the lower-level lithium storage tank. After a measured amount of lithium metal is discharged, the valve is closed. During the lithium metal discharge process, the lithium level in the lithium buffer tank remains higher than the highest point of the lithium guide tube. The lithium guide tube extends from the top or side of the lithium buffer tank. The lithium guide tube is inserted with its beginning end higher than its end end. The high limit of the lithium level in the lithium buffer tank is higher than the highest point of the lithium guide tube, and the low limit of the lithium level in the lithium buffer tank is higher than the beginning end of the lithium guide tube. Alternatively, the lithium guide tube is inserted from the top or side of the lithium buffer tank with its beginning end lower than its end end. The high limit of the lithium level in the lithium buffer tank is higher than the highest point of the lithium guide tube, and the low limit of the lithium level in the lithium buffer tank is higher than the end end of the lithium guide tube. A level gauge is installed in the lithium buffer tank to monitor the liquid level in real time, or two level gauges are installed to monitor the high and low limits of the liquid level respectively, or one level gauge is installed to monitor the high limit of the liquid level.

2. The apparatus for quantitatively exporting liquid lithium metal from a lithium electrolyzer according to claim 1, characterized in that: The liquid level monitoring instruments include magnetic levitation ball liquid level gauges, ultrasonic liquid level gauges, radar liquid level gauges, and conductive liquid level gauges.

3. The apparatus for quantitatively exporting liquid lithium metal from a lithium electrolyzer according to claim 1, characterized in that: The valves on the lithium conductor include automatic control and manual control, and the valves include shut-off valves and ball valves.

4. The apparatus for quantitatively exporting liquid lithium metal from a lithium electrolyzer according to claim 1, characterized in that: The beginning and / or end of the lithium-conducting tube are provided with a filter device for filtering solid impurities in the liquid lithium metal.

5. The apparatus for quantitatively exporting liquid lithium metal from a lithium electrolyzer according to claim 1, characterized in that: The lithium storage tank can be mobile or stationary.

6. A method for extracting liquid lithium metal using the apparatus described in any one of claims 1-5, characterized in that, When using one level gauge to monitor the liquid level in real time, or using two level gauges to monitor the high and low limits of the liquid level respectively, the following steps are included: Step S01: Based on the lithium liquid level height H 0 Internal pressure of lithium buffer tank P 0 Electrolyte liquid level H 1 Electrolysis chamber pressure P 1 Cross-sectional area of ​​lithium buffer tank S 0 Lithium liquid density ρ Li Electrolyte density ρ Ba Determine the mass of liquid lithium metal in the lithium buffer tank. M ; Step S02: Set the high limit of lithium liquid level in the lithium buffer tank. H max and lithium liquid level low limit H min The mass of lithium in the lithium buffer tank before and after exporting liquid lithium metal M max and M min ; Step S03: Based on the electrolytic cell current I Lithium-ion battery chemical equivalent C Time to extract liquid lithium metal t Electrolytic cell current efficiency η The characteristics determine the lithium revision factor M mod Calculate and derive the mass of liquid lithium metal m ; 。 7. A method for extracting liquid lithium metal using the apparatus described in any one of claims 1-5, characterized in that, When using a level gauge to monitor the high limit of the liquid level, the following steps are included: Step S1: The level monitoring gauge locates the high limit of the lithium liquid level in the lithium buffer tank. H max Set the lower limit of the lithium level in the lithium buffer tank. H min ; Step S2: Based on the time of exporting liquid lithium metal t Cross-sectional area of ​​lithium-ion transistor S Calculate and derive the mass of liquid lithium metal m ; 。

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