A lithium ingot casting system in a metal lithium closed environment and a lithium ingot casting method

Abstract

The application belongs to the technical field of metal lithium preparation, and discloses a lithium ingot casting system in a metal lithium closed environment and a lithium ingot casting method. The lithium ingot casting system is used for receiving high-temperature liquid metal lithium after distillation and purification to perform casting, cutting and bagging in a mold. The lithium ingot casting system comprises a glove box and a mold arranged in the glove box. The glove box is provided with a gas circulation module. The glove box is connected with the inside of the glove box by the gas circulation module and controls the gas environment in the glove box. The glove box is provided with at least two independent chambers, i.e. a preparation chamber and an operation chamber. At least one of the preparation chamber and the operation chamber is provided with a buffer chamber connected with the outside for material exchange. The buffer chamber is provided with detachable sealing structures on the ports connected with the outside and the inside for sealing, and the independent gas environment control is realized by connecting the gas circulation module. The mold is arranged in the operation chamber. The mold comprises a cooling support and a plurality of mold barrels arranged on the cooling support. The mold barrels are detachably connected with the cooling support.

Description

Technical Field

[0001] This invention belongs to the field of lithium metal preparation technology, specifically relating to a lithium ingot casting system and a lithium ingot casting method in a closed environment. Background Technology

[0002] Solid-state batteries are a type of battery technology. Unlike the commonly used lithium-ion and lithium-ion polymer batteries, solid-state batteries use solid electrodes and solid electrolytes. Solid-state lithium battery technology uses a glass compound made of lithium and sodium as the conductive material, replacing the electrolyte in traditional lithium batteries, which greatly improves the energy density of lithium batteries. The preparation of high-purity metallic lithium, the core material of solid-state lithium batteries, is a crucial step in their development.

[0003] High-purity lithium metal is typically extracted first using electrolysis to obtain industrial-grade lithium metal with a purity of 96-99%. Further purification is then used to obtain high-purity lithium metal. Traditional lithium metal purification mainly employs distillation to separate impurity elements such as sodium, potassium, and other impurities from the lithium metal, refining the industrial-grade crude lithium to high-purity lithium metal with a purity of 99.9%-99.99% or higher. The mechanism of this method is that various metal elements have different vapor pressures at certain temperatures. By utilizing the difference in evaporation and condensation rates, impurity elements (mainly sodium, potassium, and other heavy metals) can be separated from the lithium metal, thus achieving purification. The ratio of the vapor pressure of the impurity element to the vapor pressure of lithium metal at different temperatures is called the relative evaporation rate, denoted by A. Its formula is: A = Px / Pli, (where Px is the vapor pressure of the impurity element, and Pli is the vapor pressure of lithium metal). When A > 1, the volatilization rate of impurity elements is greater than that of lithium metal; when A < 1, the volatilization rate of impurity elements is less than that of lithium metal; when A = 1, the volatilization rate of impurity elements is equal to that of lithium metal. By controlling the material temperature within the distillation furnace during the heating of the raw lithium material, impurity elements can be separated from the raw lithium, thereby achieving the purpose of distilling and purifying lithium metal.

[0004] In existing methods, high-purity metallic lithium is directly cast in a glove box. Since high-purity elemental lithium is quite reactive and easily reacts with water, oxygen, and even nitrogen, the casting environment requires strict conditions. At the same time, lithium has a low melting point and is relatively soft in solid form, making it difficult to demold during casting. It tends to stick to the mold and leave residue. Reusing the same mold results in non-standard lithium ingots. Secondary demolding leaves even more residue and makes it difficult to apply a release agent effectively. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides a lithium ingot casting system and a lithium ingot casting method in a closed environment of metallic lithium. By optimizing the structure of the existing glove box and coordinating the two chambers, the mold can be replenished and replaced in a timely manner, thereby improving casting efficiency while ensuring that the mold is not reused for each lithium ingot casting.

[0006] The technical solution adopted in this invention is as follows:

[0007] In a first aspect, the present invention provides a lithium ingot casting system in a closed environment for receiving high-temperature liquid lithium metal after distillation and purification, for casting, cutting and bagging in a mold, including a glove box and a mold disposed in the glove box. The glove box has a gas circulation module, which connects to the inside of the glove box and controls the gas environment inside the glove box.

[0008] The glove box has at least two independent chambers, namely a preparation chamber and an operation chamber. At least one of the preparation chamber and the operation chamber has a buffer chamber that connects to the outside for material exchange. The buffer chamber has a removable sealing structure at the ports connecting to the outside and the inside for sealing, and independent gas environment control is achieved by connecting to a gas circulation module.

[0009] The mold is set inside the operating cavity. The mold includes a cooling bracket and several mold barrels set on the cooling bracket. The mold barrels are detachably connected to the cooling bracket.

[0010] The operating chamber is equipped with a feeding mechanism and a coating mechanism corresponding to the cooling bracket. The coating mechanism coats the surface of the mold barrel placed on the cooling bracket with release oil. Molten lithium metal is introduced into the mold barrel through the feeding mechanism connected to the external high-temperature storage tank. The cooling bracket, which is connected to the working fluid circulation mechanism set in the glove box, contacts the mold barrel to cool it down.

[0011] A material transfer rack is also provided between the operating chamber and the preparation chamber. The material transfer rack is slidably connected to the inside of the glove box and can slide back and forth between the operating chamber and the preparation chamber. The material transfer rack is provided with hooks for hanging the mold barrel, and the mold barrel is transferred between the operating chamber and the preparation chamber through the material transfer rack.

[0012] The material transfer rack has a blocking block, and there is a channel between the operating chamber and the preparation chamber for the material transfer rack to pass through. The blocking block has an end that blocks and seals any opening of the channel.

[0013] In conjunction with the first aspect, the present invention provides a first embodiment of the first aspect, wherein the gas circulation device includes a pipeline, a gas source, a power section and a purification section, and the pipeline includes an intake pipeline, an exhaust pipeline and a circulation pipeline;

[0014] The intake pipe is connected in sequence to the air source, the power unit and the glove box chamber, and the power unit controls the injection of protective gas into the chamber;

[0015] The exhaust pipe connects the chamber, the power unit, and the outside in sequence, and the power unit discharges the gas in the chamber to the outside.

[0016] The circulation pipeline connects the chamber, the power unit, the purification unit, and the chamber in sequence. The power unit controls the gas in the chamber to be treated by the purification unit and then returned to the chamber.

[0017] In conjunction with the first embodiment of the first aspect, the present invention provides a second embodiment of the first aspect, wherein the gas source is a high-pressure argon gas tank.

[0018] In conjunction with the first aspect, the present invention provides a third embodiment of the first aspect, wherein the cooling bracket includes a hollow shell, and the shell has a contact cavity filled with working fluid, the contact cavity being connected to an external working fluid circulation mechanism through a pipeline for working fluid circulation;

[0019] The shell has at least one flat surface with several grooves on it. The mold barrel is placed in the grooves and the outer surface of the mold barrel is in contact with the inner surface of the grooves for heat transfer.

[0020] In conjunction with the first aspect, the present invention provides a fourth embodiment of the first aspect, wherein the mold barrel includes a conical barrel body with two openings, an upper and a lower opening, and a bottom cover is provided on the lower small opening. The diameter of the bottom cover is larger than the diameter of the lower opening of the barrel body and fits against the inner wall of the opening near the lower opening.

[0021] A fluororubber sleeve is provided between the outer end face of the bottom cover and the outer wall of the opening at the bottom of the barrel to cover the gap between the bottom cover and the barrel. When the bottom cover is attached to the inner wall of the barrel, its outer bottom has a protruding part that protrudes from the opening end face at the bottom of the barrel. By squeezing the part, the bottom cover is pushed toward the opening at the top of the barrel.

[0022] In conjunction with the first aspect, the present invention provides a fifth embodiment of the first aspect, wherein the mold barrel is a conical structure formed by two sub-parts cut along its axis and fastened together.

[0023] In conjunction with the first aspect, the present invention provides a sixth embodiment of the first aspect, wherein the coating mechanism includes a liquid guiding column and a soft sleeve layer sleeved outside the liquid guiding column. One end of the liquid guiding column has a feed port, which is connected to an external feeding mechanism for holding release oil through a pipeline. The surface of the liquid guiding column also has a plurality of discharge ports connected to the feed port. The soft sleeve layer covers the surface of the liquid guiding column with discharge ports and forms a cavity for storing release oil between the soft sleeve layer and the surface of the liquid guiding column.

[0024] The surface of the soft sleeve layer is uniformly covered with several slits. The slits are initially closed. When the soft sleeve layer is driven into the mold barrel by the liquid guide column and adheres to the mold barrel to form a compression, the slits expand, causing the release oil in the soft sleeve layer to be squeezed out and adhere to the inner wall of the mold barrel.

[0025] In conjunction with the sixth embodiment of the first aspect, the present invention provides a seventh embodiment of the first aspect, wherein the liquid guiding column has a smooth cylindrical surface, the discharge port is disposed on the surface of the cylindrical surface, and annular grooves are respectively provided on the upper and lower sides of the cylindrical surface, and the soft sleeve layer has a retaining ring that is snapped into the annular groove;

[0026] The soft sleeve layer between the retaining rings has several baffles arranged at the same central angle around the axis of the liquid guiding column. The baffles are an integral structure extending inward from the soft sleeve layer. They abut against the cylindrical surface of the liquid guiding column and provide support when the soft sleeve layer contacts and is squeezed against the inner wall of the mold barrel. When the liquid guiding column drives them to rotate around the axis, the outer end of the baffle contacts the inner wall of the mold barrel to scrape oil.

[0027] In conjunction with the sixth embodiment of the first aspect, the present invention provides an eighth embodiment of the first aspect, wherein the bottom of the operating cavity has a slide rail, and the material transfer frame has a trolley that cooperates with the slide rail, and the trolley, which is always located in the operating cavity, cooperates with the trolley to support the movement of the material transfer frame.

[0028] Secondly, the present invention also provides a method for casting lithium ingots, wherein lithium ingots are cast using the lithium ingot casting system with a closed environment of metallic lithium described above, and the specific steps are as follows:

[0029] First, prepare the mold barrel, check the amount of gas source, molten lithium metal in the feeding mechanism, release oil, and working fluid, and put the mold barrel into the preparation chamber.

[0030] Then, the external sealing structure of the preparation chamber is closed, and the gas environment in the preparation chamber and the operation chamber is adjusted to the state required for casting through the gas circulation module;

[0031] Then, outside the preparation chamber, the mold barrel placed inside the preparation chamber is placed on the material transfer rack by hand using gloves. The mold barrel is transferred to the operation chamber by moving the material transfer rack, and the block on the material transfer rack in the preparation chamber is used to block and seal the passage. Then, the circulation mode of the gas circulation module is started to circulate the gas in the operation chamber to maintain the gas environment.

[0032] Outside the operating chamber, a person using gloves removes the mold barrel placed on the material transfer rack to obtain the quantity required for a single casting. Then, the mold barrel is placed on the cooling rack, and the working fluid circulation mechanism is turned on to circulate the working fluid.

[0033] To carry out the casting operation, keep the temperature of the metallic lithium in the external high-temperature storage tank at no less than 230°C. Inject molten metallic lithium into the mold barrels placed on the cooling support by operating the feeding mechanism. After all the mold barrels on the cooling support are filled, stop casting and wait for the metallic lithium in the mold barrels to cool to a conical solid lithium.

[0034] After forming the conical solid lithium, all the mold barrels on the cooling support are removed, and another person uses gloves in the operating chamber to demold them inside the operating chamber. The demolded conical solid lithium is trimmed to form lithium ingots and packaged. The packaged lithium ingots are placed in the buffer chamber or operating chamber for further processing. At the same time, the casting personnel continue to remove the mold barrels from the material transfer rack and place them on the cooling support for recasting.

[0035] During the casting operation, a new mold barrel is placed in the preparation chamber from the outside of the preparation chamber, and the gas environment in the preparation chamber is made consistent with that in the operating chamber through the gas circulation module. After all the mold barrels are cast in the operating chamber, the demolded mold barrels are exchanged with the new mold barrels through the material transfer bracket.

[0036] Once the packaged lithium ingots in the operating chamber have accumulated to their maximum quantity, they are transferred out through the buffer chamber.

[0037] The beneficial effects of this invention are as follows:

[0038] (1) The present invention adopts a two-chamber structure design to meet the requirements of mold replacement. Without stopping the casting process, the used mold can be replaced through the preparation chamber at the same time, without affecting the gas environment in the operating chamber, thus ensuring the stability of the casting operation.

[0039] (2) The present invention, through the structure of the material transfer frame, can quickly transfer a certain amount of mold barrels while ensuring a certain airtightness of the two chambers, thereby avoiding the impact on casting efficiency due to the replacement of mold barrels.

[0040] (3) By optimizing the gas circulation device, the design of three pipelines can not only quickly discharge the gas in the chamber at the beginning, but also replenish the inert gas source. After the content of oxygen, nitrogen, carbon dioxide and water in the gas environment in the chamber is lower than a certain amount, the circulation pipeline is opened to continue the circulation and purification, and the content of the above-mentioned gases after filtration is kept below 10ppm, thereby reducing the waiting preparation time and improving stability.

[0041] (4) The present invention, through the combination of the cooling bracket and the mold barrel, not only makes it easy to quickly take out the mold barrel after casting and cooling and demold it outside, but also allows for quick replacement of the mold barrel. At the same time, the cooling bracket can cool several mold barrels at the same time. The sealed structure design avoids the working fluid from contacting the inside of the chamber, and only the cooling bracket and the mold barrel exchange heat.

[0042] (5) This invention optimizes the mold barrel and achieves a fast demolding effect through a movable bottom cover structure. At the same time, by wrapping the gap between the bottom cover and the barrel body with a fluororubber sleeve, the bottom cover can be prevented from falling off, and its sealing effect can be further improved to prevent lithium metal from leaking out from the gap between the bottom cover and the barrel body. The low melting point of lithium metal is used to meet its heat resistance.

[0043] (6) This invention has a special brushing mechanism that works with the mold barrel to quickly brush oil, so that the inner wall surface of the mold barrel is evenly covered with release oil. Unlike casting of other materials, lithium metal is soft and difficult to demold. The release agent is also different from other materials, mainly consisting of special white oil. Direct spraying of this release agent has poor effect. The liquid guiding column with a soft sleeve can not only squeeze the oil out and coat it on the inner wall of the mold barrel, but also use the soft sleeve to evenly brush the oil out on its surface by rotating the liquid guiding column. It can automatically coat and improve efficiency, and can also form a relatively homogeneous release oil coating layer, thereby improving demolding efficiency.

[0044] (7) By optimizing the casting method using the system, the present invention can ensure that the casting process can continue after the casting starts by having several people operate the same equipment at regular intervals, thereby significantly improving the casting efficiency. Attached Figure Description

[0045] Figure 1 This is a front view of the entire system of the present invention;

[0046] Figure 2 This is a first-angle isometric schematic diagram of the entire system of the present invention;

[0047] Figure 3 This is a side view of the entire system of the present invention;

[0048] Figure 4 This is a second-angle isometric schematic diagram of the entire system of the present invention;

[0049] Figure 5 This is a flowchart of the method of the present invention.

[0050] In the picture:

[0051] 1-Preparation chamber, 2-Operating chamber, 3-Buffer chamber, 4-Gas circulation device, 5-Material transfer rack, 6-Painting mechanism, 7-Liquid guide column, 8-Mold barrel, 9-Cabinet. Detailed Implementation

[0052] The present invention will be further explained below with reference to the accompanying drawings and specific embodiments.

[0053] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0054] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0055] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0056] In the description of this application, it should be noted that the use of terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" to indicate orientation or positional relationships is based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationships commonly used when the product is in use. These terms are used solely for the convenience of describing this application and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the use of terms such as "first" and "second" in the description of this application is only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0057] Furthermore, the use of terms such as "horizontal" and "vertical" in the description of this application does not imply that the component is required to be absolutely horizontal or suspended, but rather that it may be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but rather that it may be slightly tilted.

[0058] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0059] Example 1:

[0060] This embodiment discloses a lithium ingot casting apparatus in a closed environment for metallic lithium, referring to... Figures 1-4 It is used in the lithium distillation and purification process to receive high-temperature liquid lithium metal stored in storage tanks after purification and to cast it.

[0061] It should be noted that the temperature of high-temperature liquid lithium metal is maintained above 220°C, which is lower than that of other metal materials. This reduces the requirements for materials and makes it easier to transport and handle.

[0062] In existing technologies, lithium ingot casting is mostly carried out in a glove box. It is necessary to maintain a stable gaseous environment during the casting process, and the contents of oxygen, nitrogen, and water need to be monitored in real time to prevent reactions from the relatively reactive lithium metal. Existing technologies often use inert gases or dry air to fill the glove box. However, considering that lithium metal can react even with prolonged exposure to dry air, this embodiment uses argon as an alternative filling gas.

[0063] The lithium ingot casting apparatus of this embodiment is an optimized improvement on the existing glove box, thereby providing a highly efficient casting device suitable for high-purity metallic lithium. Specifically, it includes a glove box, a gas circulation module, a mold, and a feeding mechanism for casting. The lithium ingot is formed by casting onto the mold through an operable pipe on the feeding mechanism or other mechanism that allows molten metallic lithium to fall out, cooling, and demolding.

[0064] The glove box comprises at least two units, arranged side-by-side and connected on one side. Each glove box consists of a base frame and a box body. The main body of the box body is constructed from sheet metal and secured to the base frame using bolts or welding. The base frame is constructed from metal tubing and has casters for movement within the factory area. A cabinet 9 is mounted on the base frame for housing some components.

[0065] The front of the box is fitted with a transparent tempered glass panel, and at least one set of openings are provided on the glass panel. Each opening is fitted with a latex or fluororubber glove, and the operator puts their hand into the glove outside the glove box to operate.

[0066] The two sets of glove boxes are divided into an operation box and a preparation box. The inside of the operation box is the operation chamber 2, and the inside of the preparation box is the preparation chamber 1. At least one of the preparation chamber 1 and the operation chamber 2 has a buffer chamber 3 that connects to the outside for material exchange. The buffer chamber 3 has a detachable sealing structure at the ports connecting to the outside and the inside for sealing, and achieves independent gas environment control by connecting to a gas circulation module.

[0067] Reference Figure 1 The two glove boxes share a common partition with a channel for facilitating the delivery of items from the preparation chamber 1 to the operation chamber 2. The mold is located within the operation chamber 2 and includes a cooling support and several mold barrels 8 mounted on the cooling support. The mold barrels 8 are detachably connected to the cooling support. The operation chamber 2 is equipped with a feeding mechanism and a coating mechanism 6 corresponding to the cooling support. The coating mechanism 6 applies release oil to the surface of the mold barrels 8 placed on the cooling support. Molten lithium metal is introduced into the mold barrels 8 through the feeding mechanism connected to an external high-temperature storage tank. The cooling support, connected to a working fluid circulation mechanism within the glove box, contacts and cools the mold barrels 8.

[0068] A material transfer frame 5 is also provided between the operating chamber 2 and the preparation chamber 1. The material transfer frame 5 is slidably connected to the inside of the glove box and can slide back and forth between the operating chamber 2 and the preparation chamber 1. The material transfer frame 5 is provided with a hook for hanging the mold barrel 8. The mold barrel 8 is transferred between the operating chamber 2 and the preparation chamber 1 through the material transfer frame 5. The material transfer frame 5 has a blocking block, and there is a channel between the operating chamber 2 and the preparation chamber 1 for the material transfer frame 5 to pass through. The blocking block has an end that blocks and seals any opening of the channel.

[0069] In some embodiments, the operating chamber 2 is used only as a casting area and has only one set of gloves for a single person to perform casting operations using the mold and feeding mechanism. The buffer chamber 3 is located on one side of the preparation chamber 1 and has at least two sets of gloves. The operator passes the mold barrel 8 to the preparation chamber 1 or to the outside through the buffer chamber 3. At the same time, the cooled mold barrel 8 passed from the operating chamber 2 is demolded. Then, the demolded lithium metal is packaged in the operating chamber 2, and the demolded mold barrel 8 is placed on a prepared frame or shelf for easy delivery together.

[0070] In other embodiments, refer to Figure 4Preparation chamber 1 serves only as a material preparation area and contains only one set of gloves. Operating chamber 2, with a larger volume, has two operating areas, left and right. Buffer chamber 3 is located on the right side of operating chamber 2. The left operating area, near the preparation chamber, is used for casting. A feeding mechanism is located at the top of this area, connected to an external high-temperature storage tank via pipeline. A control system is also installed between the high-temperature storage tank and the feeding mechanism to quantitatively deliver metallic lithium from the high-temperature storage tank.

[0071] A cooling support is provided at the bottom of the feeding mechanism, and the operator places several clean mold barrels 8 on the cooling support. The feeding mechanism has a nozzle that can be raised or pulled by a rope. The nozzle is set at a fixed point and is directly facing the mold barrels 8 on the cooling support. The control system controls the injection of metallic lithium into the mold barrels 8 at a constant speed and in a fixed quantity.

[0072] A coating mechanism 6 is also fixed on one side of the feeding mechanism. The coating mechanism 6 can be raised and lowered manually or automatically. When the new mold barrel 8 is placed on the cooling support, the coating mechanism 6 is lowered into the corresponding mold barrel 8 to apply release oil. The coating mechanism 6 includes various methods, such as having only one structure that moves in several mold barrels 8 to perform coating, or having the same number of structures as the mold barrels 8 on the cooling support, so that a single descent can coat the entire mold barrel 8 on the cooling support.

[0073] Meanwhile, a working fluid circulation mechanism, namely a water tank assembly with a water pump, is installed in the support at the lower part of the operating chamber 2. It is connected to the cooling support through a pipe. The working fluid is generally water. The flowing water exchanges heat with the mold barrel 8 at a higher temperature, thereby achieving the cooling effect.

[0074] A placement frame is provided in the area on the left. Another operator will demold the cooled mold barrel 8 taken from the cooling bracket, cut the demolded lithium block into pieces, and place it in a packaging bag after it has formed a standard lithium ingot. The packaging bag will be filled with a certain amount of argon gas by the gas circulation module in this area and then sealed. The sealed lithium ingots will be placed in the placement frame and when they have accumulated to a certain amount, the operator will send the placement frame out from the buffer chamber 3.

[0075] Reference Figure 5 This embodiment also provides a method for casting lithium ingots, the specific steps of which are as follows:

[0076] First, prepare the mold barrel 8, check the amount of molten lithium metal, release oil, and working fluid in the gas source and feeding mechanism, and put the mold barrel 8 into the preparation chamber 1; then close the external sealing structure of the preparation chamber 1, and adjust the gas environment in the preparation chamber 1 and the operating chamber 2 to the state required for casting through the gas circulation module.

[0077] Then, outside the preparation chamber 1, the mold barrel 8 placed inside the preparation chamber 1 is placed on the material transfer rack 5 by hand using gloves. The mold barrel 8 is transferred to the operation chamber 2 by moving the material transfer rack 5, and the block on the material transfer rack 5 in the preparation chamber 1 is used to block and seal the passage. Then, the circulation mode of the gas circulation module is started to circulate the gas in the operation chamber 2 to maintain the gas environment.

[0078] Outside the operating chamber 2, a person using gloves removes the mold barrel 8, which is placed on the material transfer rack 5, to the quantity required for a single casting. Then, the mold barrel 8 is placed on the cooling rack, and the working fluid circulation mechanism is turned on to circulate the working fluid.

[0079] To carry out the casting operation, keep the temperature of the metallic lithium in the external high-temperature storage tank at no less than 230°C. Inject molten metallic lithium into the mold barrel 8 placed on the cooling support by operating the feeding mechanism. After all the mold barrels 8 on the cooling support are filled, stop casting and wait for the metallic lithium in the mold barrel 8 to cool to a conical solid lithium.

[0080] After forming the conical solid lithium, all the mold barrels 8 on the cooling support are removed, and another person uses gloves in the operating chamber 2 to demold them inside the operating chamber 2. The demolded conical solid lithium is trimmed to form lithium ingots and packaged. The packaged lithium ingots are placed in the buffer chamber 3 or the operating chamber 2 for processing. At the same time, the casting personnel continue to remove the mold barrels 8 on the material transfer rack 5 and place them on the cooling support for recasting.

[0081] During the casting operation, a new mold barrel 8 is placed in the preparation chamber 1 from the outside of the preparation chamber 1, and the gas environment in the preparation chamber 1 is made consistent with that in the operation chamber 2 through the gas circulation module. After all the mold barrels 8 are cast in the operation chamber 2, the demolded mold barrels 8 are exchanged with the new mold barrels 8 through the material transfer bracket. When the packaged lithium ingots in the operation chamber 2 accumulate to the maximum number, they are transferred out through the buffer chamber 3.

[0082] Furthermore, the gas circulation device 4 includes pipelines, a gas source, a power unit, and a purification unit. The pipelines include an inlet pipeline, an exhaust pipeline, and a circulation pipeline. The inlet pipeline is connected in sequence to the gas source, the power unit, and the glove box chamber, and the power unit controls the injection of protective gas into the chamber. The exhaust pipeline is connected in sequence to the chamber, the power unit, and the outside, and the power unit discharges the gas from the chamber to the outside. The circulation pipeline is connected in sequence to the chamber, the power unit, the purification unit, and the chamber, and the power unit controls the return of the gas in the chamber to the chamber after it has been treated by the purification unit.

[0083] The chamber has a gas recovery port and a gas exhaust port, both of which are disc-shaped structures protruding from their surfaces. A gap exists between the disc and the bottom plate of the chamber, allowing gas to pass through. The gas recovery port connects to the exhaust pipe and the circulation pipe, while the gas exhaust port connects to the inlet pipe and the circulation pipe. Additionally, a separate gas outlet structure connected to a gas source is located within the operating chamber 2, used for argon filling of lithium ingots packaged in bags.

[0084] Furthermore, the cooling bracket includes a hollow shell with a contact cavity filled with working fluid inside. The contact cavity is connected to an external working fluid circulation mechanism through a pipeline to circulate the working fluid. The shell has at least one flat surface with several sinks on the flat surface. The mold barrel 8 is placed in the sink and the outer surface of the mold barrel 8 is in contact with the inner surface of the sink for heat transfer.

[0085] The mold barrel 8 includes a conical barrel body with two openings, one at the top and one at the bottom. A bottom cover is provided on the lower opening, the diameter of which is larger than the diameter of the lower opening of the barrel body and fits against the inner wall of the opening near the bottom. A fluororubber sleeve is provided between the outer end face of the bottom cover and the outer wall of the lower opening of the barrel body to cover the gap between the bottom cover and the barrel body. When the bottom cover fits against the inner wall of the barrel body, its outer bottom has a protruding part that protrudes from the lower opening end face of the barrel body. By pressing the part, the bottom cover is pushed towards the opening at the top of the barrel body.

[0086] Furthermore, the coating mechanism 6 includes a liquid guiding column 7 and a soft sleeve layer sleeved outside the liquid guiding column 7. One end of the liquid guiding column 7 has a feed port, which is connected to an external feeding mechanism for storing release oil through a pipeline. The surface of the liquid guiding column 7 also has several discharge ports connected to the feed port. The soft sleeve layer covers the surface of the liquid guiding column 7 with discharge ports and forms a cavity for storing release oil between the soft sleeve layer and the surface of the liquid guiding column 7. The surface of the soft sleeve layer is uniformly covered with several slits. The slits are initially closed. When the liquid guiding column 7 drives the soft sleeve layer into the mold barrel 8 and adheres to the mold barrel 8 to form a compression, the slits expand, causing the release oil in the soft sleeve layer to be squeezed out and adhere to the inner wall of the mold barrel 8.

[0087] Reference Figure 1 Several liquid guide columns 7 are mounted on the same bracket and fixed within the operating chamber 2, allowing for lifting and lowering. A motor on this bracket drives all the parallel liquid guide columns 7 to rotate at the same speed around its axis via a motor and belt. The center of each liquid guide column 7 is a feed inlet, and the top of the inlet is connected to an external feeding mechanism via a rotary sealing structure. When a liquid guide column 7 descends and enters its corresponding mold barrel 8, the feeding mechanism first fills the liquid guide column 7 with a measured amount of release oil. Then, the motor controls all the liquid guide columns 7 to rotate the soft sleeve layer, evenly scraping the release oil onto the surface of the mold barrel 8.

[0088] The liquid guiding column 7 has a smooth cylindrical surface, and the discharge port is located on the surface of the cylindrical surface. Annular grooves are respectively provided on the upper and lower sides of the cylindrical surface. The soft sleeve layer has retaining rings that are snapped into the annular grooves. The soft sleeve layer between the retaining rings has several baffles arranged at equal central angles around the axis of the liquid guiding column 7. The baffles are integral structures extending inward from the soft sleeve layer. They abut against the cylindrical surface of the liquid guiding column 7 and provide support when the soft sleeve layer contacts and is squeezed against the inner wall of the mold barrel 8. When the liquid guiding column 7 drives the baffles to rotate around the axis, the outer end of the baffle contacts the inner wall of the mold barrel 8 to scrape oil.

[0089] This invention is not limited to the optional embodiments described above, and anyone can derive other various forms of products based on the inspiration of this invention. The specific embodiments described above should not be construed as limiting the scope of protection of this invention; the scope of protection of this invention should be determined by the claims, and the specification can be used to interpret the claims.

Claims

1. A lithium ingot casting system in a closed environment for receiving, casting, cutting, and bagging high-temperature liquid lithium metal after distillation and purification in a mold, characterized in that: It includes a glove box and a mold set inside the glove box. The glove box has a gas circulation module, which connects the inside of the glove box and controls the gas environment inside the glove box. The glove box has at least two independent chambers, namely a preparation chamber and an operation chamber. At least one of the preparation chamber and the operation chamber has a buffer chamber that connects to the outside for material exchange. The buffer chamber has a removable sealing structure at the ports connecting to the outside and the inside for sealing, and independent gas environment control is achieved by connecting to a gas circulation module. The mold is set inside the operating cavity. The mold includes a cooling bracket and several mold barrels set on the cooling bracket. The mold barrels are detachably connected to the cooling bracket. The operating chamber is equipped with a feeding mechanism and a coating mechanism corresponding to the cooling bracket. The coating mechanism coats the surface of the mold barrel placed on the cooling bracket with release oil. Molten lithium metal is introduced into the mold barrel through the feeding mechanism connected to the external high-temperature storage tank. The cooling bracket, which is connected to the working fluid circulation mechanism set in the glove box, contacts the mold barrel to cool it down. A material transfer rack is also provided between the operating chamber and the preparation chamber. The material transfer rack is slidably connected to the inside of the glove box and can slide back and forth between the operating chamber and the preparation chamber. The material transfer rack is equipped with hooks for hanging mold barrels, and the mold barrels are transferred between the operating chamber and the preparation chamber through the material transfer rack; The material transfer rack has a blocking block, and there is a channel between the operating chamber and the preparation chamber for the material transfer rack to pass through. The blocking block has an end that blocks and seals any opening of the channel.

2. The lithium ingot casting system in a closed environment of metallic lithium according to claim 1, characterized in that: The gas circulation module includes pipelines, a gas source, a power unit, and a purification unit. The pipelines include an intake pipeline, an exhaust pipeline, and a circulation pipeline. The intake pipe is connected in sequence to the air source, the power unit and the glove box chamber, and the power unit controls the injection of protective gas into the chamber; The exhaust pipe connects the chamber, the power unit, and the outside in sequence, and the power unit discharges the gas in the chamber to the outside. The circulation pipeline connects the chamber, the power unit, the purification unit, and the chamber in sequence. The power unit controls the gas in the chamber to be treated by the purification unit and then returned to the chamber.

3. The lithium ingot casting system in a closed environment of metallic lithium according to claim 2, characterized in that: The gas source is a high-pressure argon gas cylinder.

4. The lithium ingot casting system in a closed environment of metallic lithium according to claim 1, characterized in that: The cooling bracket includes a hollow shell with a contact cavity filled with working fluid inside. The contact cavity is connected to an external working fluid circulation mechanism through a pipeline to circulate the working fluid. The shell has at least one flat surface with several grooves on it. The mold barrel is placed in the grooves and the outer surface of the mold barrel is in contact with the inner surface of the grooves for heat transfer.

5. The lithium ingot casting system in a closed environment of metallic lithium according to claim 1, characterized in that: The mold barrel includes a conical barrel body with two openings, one at the top and one at the bottom. A bottom cover is provided on the lower opening, which has a smaller area. The diameter of the bottom cover is larger than the diameter of the lower opening of the barrel body and fits against the inner wall of the opening near the bottom. A fluororubber sleeve is provided between the outer end face of the bottom cover and the outer wall of the opening at the bottom of the barrel to cover the gap between the bottom cover and the barrel. When the bottom cover is attached to the inner wall of the barrel, its outer bottom has a protruding part that protrudes from the opening end face at the bottom of the barrel. By squeezing the part, the bottom cover is pushed toward the opening at the top of the barrel.

6. The lithium ingot casting system in a closed environment of metallic lithium according to claim 1, characterized in that: The mold barrel is a conical structure formed by two sub-parts cut along its axis and fastened together.

7. The lithium ingot casting system in a closed environment for metallic lithium according to claim 1, characterized in that: The coating mechanism includes a liquid guide column and a soft sleeve layer sleeved outside the liquid guide column. One end of the liquid guide column has a feed port, which is connected to an external feeding mechanism for holding release oil through a pipeline. The surface of the liquid guide column also has several discharge ports connected to the feed port. The soft sleeve layer covers the surface of the liquid guide column with discharge ports and forms a cavity for storing release oil between the soft sleeve layer and the surface of the liquid guide column. The surface of the soft sleeve layer is uniformly covered with several slits. The slits are initially closed. When the soft sleeve layer is driven into the mold barrel by the liquid guide column and adheres to the mold barrel to form a compression, the slits expand, causing the release oil in the soft sleeve layer to be squeezed out and adhere to the inner wall of the mold barrel.

8. A lithium ingot casting system in a closed environment for metallic lithium according to claim 7, characterized in that: The liquid guiding column has a smooth cylindrical surface, the discharge port is located on the surface of the cylindrical surface, and annular grooves are respectively provided on the upper and lower sides of the cylindrical surface. The soft sleeve has retaining rings that are snapped into the annular grooves. The soft sleeve layer between the retaining rings has several baffles arranged at the same central angle around the axis of the liquid guiding column. The baffles are an integral structure extending inward from the soft sleeve layer. They abut against the cylindrical surface of the liquid guiding column and provide support when the soft sleeve layer contacts and is squeezed against the inner wall of the mold barrel. When the liquid guiding column drives them to rotate around the axis, the outer end of the baffle contacts the inner wall of the mold barrel to scrape oil.

9. A lithium ingot casting system in a closed environment for metallic lithium according to claim 1, characterized in that: The bottom of the operating cavity has a slide rail, and the material transfer frame has a trolley that cooperates with the slide rail. The trolley, which is always in the operating cavity, cooperates with the trolley to support the movement of the material transfer frame.

10. A method for casting lithium ingots, characterized in that: Lithium ingot casting is performed using the lithium ingot casting system with a closed lithium metal environment as described in any one of claims 1-9, with the following specific steps: First, prepare the mold barrel, check the amount of gas source, molten lithium metal in the feeding mechanism, release oil, and working fluid, and put the mold barrel into the preparation chamber. Then, the external sealing structure of the preparation chamber is closed, and the gas environment in the preparation chamber and the operation chamber is adjusted to the state required for casting through the gas circulation module; Then, outside the preparation chamber, the mold barrel placed inside the preparation chamber is placed on the material transfer rack by hand using gloves. The mold barrel is transferred to the operation chamber by moving the material transfer rack, and the block on the material transfer rack in the preparation chamber is used to block and seal the passage. Then, the circulation mode of the gas circulation module is started to circulate the gas in the operation chamber to maintain the gas environment. Outside the operating chamber, a person using gloves removes the mold barrel placed on the material transfer rack to obtain the quantity required for a single casting. Then, the mold barrel is placed on the cooling rack, and the working fluid circulation mechanism is turned on to circulate the working fluid. To carry out the casting operation, keep the temperature of the metallic lithium in the external high-temperature storage tank at no less than 230°C. Inject molten metallic lithium into the mold barrels placed on the cooling support by operating the feeding mechanism. After all the mold barrels on the cooling support are filled, stop casting and wait for the metallic lithium in the mold barrels to cool to a conical solid lithium. After forming the conical solid lithium, all the mold barrels on the cooling support are removed, and another person uses gloves in the operating chamber to demold them inside the operating chamber. The demolded conical solid lithium is trimmed to form lithium ingots and packaged. The packaged lithium ingots are placed in the buffer chamber or operating chamber for further processing. At the same time, the casting personnel continue to remove the mold barrels from the material transfer rack and place them on the cooling support for recasting. During the casting operation, a new mold barrel is placed in the preparation chamber from the outside of the preparation chamber, and the gas environment in the preparation chamber is made consistent with that in the operating chamber through the gas circulation module. After all the mold barrels are cast in the operating chamber, the demolded mold barrels are exchanged with the new mold barrels through the material transfer bracket. Once the packaged lithium ingots in the operating chamber have accumulated to their maximum quantity, they are transferred out through the buffer chamber.

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