A lithium hydroxide production system

Abstract

This utility model relates to the field of lithium hydroxide production technology, specifically disclosing a lithium hydroxide production system. The system includes a slurry preparation device, a purification and impurity removal device, a filter press, a primary causticizing device, a first evaporation device, a second causticizing device, a second evaporation device, a refrigeration device, and a centrifuge device. These devices are sequentially connected and form a material circulation path. The purification and impurity removal device is equipped with a calcium oxide feed port, a crushing component, and a pretreatment mechanism. Impurities are removed at room temperature using calcium oxide, and turbidity sensing control ensures the purity of the filtrate. The primary causticizing device can return a portion of the material to the slurry preparation device for recycling. This system reduces sodium hydroxide consumption and energy consumption, improves impurity removal efficiency and raw material utilization, increases product purity, and reduces production costs.

Description

Technical Field

[0001] This utility model relates to the field of lithium hydroxide production technology, and specifically discloses a lithium hydroxide production system. Background Technology

[0002] Lithium hydroxide, as an important lithium compound, is widely used in batteries, ceramics, chemicals, and other fields, especially in the growing demand for new energy batteries. Currently, lithium hydroxide production processes typically suffer from high raw material consumption, high energy consumption, and incomplete impurity removal. Traditional production systems often rely on sodium hydroxide for causticization reactions, which is not only costly but also requires maintaining high temperatures, resulting in significant energy consumption. Furthermore, the impurity removal process suffers from low efficiency, easily leading to a decrease in the purity of subsequent products and affecting product quality. In addition, the connections between various units in existing production systems are not well-designed, and material recycling is insufficient, further increasing production costs. Therefore, there is an urgent need for a lithium hydroxide production system that can reduce raw material consumption, decrease energy consumption, improve impurity removal efficiency, and achieve efficient material recycling. Utility Model Content

[0003] The purpose of this invention is to provide a lithium hydroxide production system to solve the problems of high raw material consumption, high energy consumption, incomplete impurity removal, and insufficient material recycling in the existing technology.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: A lithium hydroxide production system includes a slurry preparation unit, a purification and impurity removal unit, a filter press unit, a primary causticizing unit, a first evaporation unit, a secondary causticizing unit, a second evaporation unit, a refrigeration unit, and a centrifuge unit. The units are connected sequentially via pipelines to form a complete production process.

[0005] The purification and impurity removal device includes a purification tank. A calcium oxide inlet is located at the top of the tank for adding calcium oxide to initiate the impurity removal reaction. A purification outlet is located at the bottom of the tank for discharging the treated material. Inside the tank, from top to bottom, are arranged a crushing component, a pretreatment mechanism, a discharge valve, and a filter screen. The crushing component crushes the added calcium oxide, improving its reactivity. The pretreatment mechanism pre-treats the calcium oxide, enhancing its reaction efficiency with the slurry. The filter screen filters out large particulate impurities from the material. A slurry inlet is located between the pretreatment mechanism and the discharge valve, connecting to the discharge port of the filter press, allowing the filtered slurry to enter the purification tank. A first turbidity sensor is installed between the slurry inlet and the discharge valve. This sensor is located on the inner wall of the purification tank and is connected to the discharge valve. The sensor controls the opening and closing of the discharge valve based on the detected turbidity, ensuring the purity of the discharged material.

[0006] Furthermore, the pulverizing component includes a rotating shaft and a blade mesh. The top end of the rotating shaft is connected to the purification tank, and the bottom end is connected to the blade mesh. A groove for accommodating the blade mesh is provided on the inner wall of the purification tank. The blade mesh can rotate in the groove, and the pulverization of calcium oxide is achieved by rotating the blade mesh.

[0007] Furthermore, the pretreatment mechanism includes a spray pipe and a reaction tank. The spray pipe is located above the reaction tank, and the inlet of the spray pipe extends out of the purification tank and is connected to a water tank, which can spray water into the reaction tank. A second turbidity sensor is installed in the reaction tank, and an outlet valve is installed at the bottom. The outlet valve is connected to the signal of the second turbidity sensor, and the opening and closing of the outlet valve is controlled according to the turbidity of the material in the reaction tank to ensure the pretreatment effect.

[0008] Furthermore, the primary causticizing unit includes a reaction vessel with a calcium oxide feed pipe on its side wall for adding calcium oxide to carry out the causticizing reaction; the reaction vessel is equipped with a spiral stirrer to ensure thorough mixing of the materials. The secondary causticizing unit includes a causticizing reaction vessel with a sodium hydroxide feed inlet at the top for adding sodium hydroxide to carry out further causticizing.

[0009] Furthermore, both the first and second evaporation devices are reduced-pressure evaporators, and the outer walls of the reduced-pressure evaporators are each equipped with a heat insulation layer, which can achieve material evaporation at a lower temperature, reduce energy consumption, and reduce heat loss.

[0010] Furthermore, the filter press includes a plate and frame filter press, the filter cake outlet of which is connected to the slag yard conveying channel for convenient centralized treatment of the filter cake; the filtrate outlet is connected to the purification and impurity removal device, and the plate and frame filter press is equipped with polypropylene filter plates and matching needle-punched felt filter cloth to improve filtration efficiency and filtrate purity.

[0011] Furthermore, the slurry preparation device includes a slurry preparation tank and a stirring assembly located inside the slurry preparation tank. The top of the slurry preparation tank is provided with a spodumene powder inlet and a water inlet. The stirring assembly is used to fully mix the spodumene powder and water to form a slurry.

[0012] Furthermore, the refrigeration device includes a low-temperature freezing tank, which is equipped with a coil-type heat exchanger to quickly reduce the temperature of the material; the outer wall of the low-temperature freezing tank is equipped with a heat insulation layer to reduce the loss of cold energy.

[0013] Furthermore, the centrifugation device includes a horizontal centrifuge, the liquid phase outlet of which is connected to a recovery tank to facilitate the recycling of liquid phase materials; the solid phase outlet is connected to a second evaporation device, allowing solid phase materials to enter the secondary evaporation stage.

[0014] The beneficial effects of this utility model are as follows: by setting up a purification and impurity removal device and using calcium oxide for impurity removal, the amount of sodium hydroxide used is reduced, thus lowering production costs; the purification and impurity removal process does not require heating, reducing energy consumption; the discharge port of the primary causticizing device is connected to the slurry preparation device, realizing the recycling of materials and improving raw material utilization; the reasonable connection between the various devices, through the synergistic effect of steps such as pressure filtration, evaporation, freezing, and centrifugation, effectively removes impurities from the materials, improving product purity; the use of equipment such as a vacuum evaporator further reduces energy consumption and ensures product quality. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall system of an embodiment of the present utility model; Figure 2 This is a front sectional view of the purification and impurity removal device in an embodiment of this utility model; Figure 3 This is a top cross-sectional view of the primary causticizing device in an embodiment of this utility model; Figure 4 This is a top sectional view of the slurry preparation device in an embodiment of the present invention; Figure 5 This is a side sectional view of the freezing device in an embodiment of the present invention; Figure 6 This is a front sectional view of the filter press device in an embodiment of this utility model.

[0016] Attached reference numerals: 1-Purification tank, 2-Groove, 3-Rotating shaft, 4-Blade screen, 5-Calcium oxide feed port, 6-Spray pipe, 7-Reaction tank, 8-Second turbidity sensor, 9-First turbidity sensor, 10-Liquid outlet valve, 11-Discharge valve, 12-Filter screen, 13-Purification outlet, 14-Water tank, 15-Slurry inlet, 16-Slurry mixing tank, 17-Spodumene powder inlet, 18-Water inlet, 19- Filter press, 20-primary causticizing unit, 21-calcium oxide feed pipe, 22-primary evaporation unit, 23-insulation layer, 24-secondary causticizing unit, 25-sodium hydroxide feed inlet, 26-refrigeration unit, 27-insulation layer, 28-centrifugal unit, 29-polypropylene filter plate, 30-needle-punched felt filter cloth, 31-spiral stirrer, 32-stirring assembly, 33-coil heat exchanger, 34-secondary evaporation unit. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0018] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0019] 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.

[0020] In the description of the embodiments of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "horizontal," "inner," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the utility model product is in use. They are only for the convenience of describing this utility model and 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 utility model. In addition, the terms "first," "second," "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0021] Furthermore, the use of terms such as "horizontal" does not imply that the component must be absolutely horizontal or suspended, but rather that it can 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 can be slightly tilted.

[0022] In the description of the embodiments of this utility model, "a plurality of" means at least two.

[0023] In the description of the embodiments of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "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 of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0024] Example This utility model discloses a lithium hydroxide production system that achieves efficient lithium hydroxide production through the synergistic effect of various devices. The system includes a slurry preparation device, a purification and impurity removal device, a filter press 19, a primary causticizing device 20, a first evaporation device, a secondary causticizing device 24, a second evaporation device, a refrigeration device 26, and a centrifuge device 28. The devices are connected by pipelines to form a continuous production process.

[0025] The discharge port of the slurry preparation device is connected to the inlet of the filter press 19, used to transport the slurry-prepared material to the filter press 19 for preliminary filtration; the discharge port of the filter press 19 is connected to the inlet of the purification and impurity removal device, allowing the filtered material to enter the purification and impurity removal device for impurity removal treatment; the filtrate outlet of the purification and impurity removal device is connected to the inlet of the primary causticizing device 20, allowing the impurity-removed filtrate to enter the primary causticizing device 20 for reaction; the discharge port of the primary causticizing device 20 is connected to the inlet of the first evaporation device and the inlet of the slurry preparation device, respectively, to achieve partial evaporation. The material is recycled and another part is processed. The discharge end of the first evaporator is connected to the inlet of the secondary causticizing device 24. The evaporated material enters the secondary causticizing device 24 for further reaction. The filtrate outlet of the secondary causticizing device 24 is connected to the freezing device 26. The causticized filtrate enters the freezing device 26 for cooling and crystallization. The discharge outlet of the freezing device 26 is connected to the centrifuge device 28. The crystallized material is separated by centrifugation. The outlet of the centrifuge device 28 is connected to the second evaporator. The centrifuged material enters the second evaporator for further evaporation.

[0026] The main function of the slurry mixing device is to mix spodumene powder with water to form a uniform slurry. The slurry mixing device includes a slurry mixing tank 16, within which a stirring assembly 32 is installed. The stirring assembly 32 can thoroughly stir the spodumene powder and water. The top of the slurry mixing tank 16 has a spodumene powder inlet 17 and a water inlet 18. The spodumene powder and water enter the slurry mixing tank 16 through their respective inlets and mix under the action of the stirring assembly 32 to form a slurry. After slurry mixing is completed, the slurry is conveyed to the filter press 19 through the outlet of the slurry mixing device. In this embodiment, the stirring assembly 32 is a spiral shaft 3, horizontally arranged within the slurry mixing tank 16. Alternatively, the stirring assembly 32 can also consist of several stirring blades, which can serve the stirring function.

[0027] The filter press 19 is used for preliminary filtration of the slurry after conditioning, removing large particulate impurities. The filter press 19 employs a plate and frame filter press, which contains polypropylene filter plates and matching needle-punched felt filter cloth 30. The combination of the filter plates and filter cloth effectively intercepts solid impurities in the slurry. The filter residue outlet of the plate and frame filter press is connected to the slag yard conveying channel, through which the filter residue is transported to the slag yard for centralized treatment. The filtrate outlet is connected to a purification and impurity removal device, where the filtered filtrate enters for further treatment.

[0028] The purification and impurity removal device is a key component for removing impurities. It includes a purification tank 1 with a calcium oxide feed port 5 at the top for adding calcium oxide. Inside the purification tank 1, from top to bottom, are a crushing assembly, a pretreatment mechanism, a discharge valve 11, and a filter screen 12. The crushing assembly includes a rotating shaft 3 and a blade mesh 4. The top end of the rotating shaft 3 is connected to the purification tank 1, and the bottom end is connected to the blade mesh 4. A groove 2 is formed in the inner wall of the purification tank 1 to accommodate the blade mesh 4, which can rotate within the groove 2. When calcium oxide enters the purification tank 1 through the feed port, it first falls into the crushing assembly. Driven by the rotating shaft 3, the blade mesh 4 crushes the calcium oxide, breaking down lumpy calcium oxide into fine particles, thus increasing its contact area with the slurry and its reactivity.

[0029] The pulverized calcium oxide enters a pretreatment unit, which includes a spray pipe 6 and a reaction tank 7. The spray pipe 6 is located above the reaction tank 7, and its inlet 18 extends out of the purification tank 1 and connects to a water tank 14. Water in the water tank 14 is sprayed into the reaction tank 7 through the spray pipe 6, mixing with the pulverized calcium oxide to undergo a pretreatment reaction, forming a form that is more readily reacted with the slurry. A second turbidity sensor 8 is installed inside the reaction tank 7, and an outlet valve 10 is located at the bottom, with the outlet valve 10 connected to the second turbidity sensor 8. When the second turbidity sensor 8 detects that the turbidity of the material in the reaction tank 7 reaches a set value, the outlet valve 10 opens, and the pretreated material enters the next stage.

[0030] A slurry inlet 15 is provided between the pretreatment unit and the discharge valve 11. This slurry inlet 15 is connected to the filtrate outlet of the filter press 19. The filtrate after filtration enters the purification tank 1 through the slurry inlet 15, where it is fully mixed and reacted with the pretreated calcium oxide to remove impurities such as iron and magnesium from the slurry. A first turbidity sensor 9 is installed between the slurry inlet 15 and the discharge valve 11. This sensor is signal-connected to the discharge valve 11. When the turbidity of the material is detected to meet the requirements, the discharge valve 11 opens, and the material is filtered through the filter screen 12 and discharged through the outlet at the bottom of the purification tank 1. The filter screen 12 can further filter large particulate impurities in the material to ensure the purity of the filtrate entering subsequent devices.

[0031] The filtrate discharged from the purification and impurity removal device enters the primary causticizing unit 20 through a pipeline. The primary causticizing unit 20 includes a reaction tank with a calcium oxide feed pipe 21 on its side wall, allowing calcium oxide to be added into the tank. A spiral stirrer 31 inside the tank stirs the material, ensuring that the calcium oxide reacts fully with the filtrate to carry out the causticizing reaction. The outlet of the primary causticizing unit 20 is connected to the feed end of the first evaporation device and the feed end of the slurry preparation device, respectively. Part of the material enters the first evaporation device for evaporation treatment, while the other part flows back to the slurry preparation device, achieving recycling and improving the raw material utilization rate.

[0032] The material entering the first evaporation unit is evaporated and concentrated in a vacuum evaporator. The outer wall of the vacuum evaporator is equipped with an insulation layer 23 to reduce heat loss and energy consumption. The evaporated and concentrated material enters the secondary causticizing unit 24 through the outlet of the first evaporation unit. The secondary causticizing unit 24 includes a causticizing reaction vessel with a sodium hydroxide inlet 25 at the top. Sodium hydroxide is added to carry out further causticizing reaction to ensure complete reaction.

[0033] The filtrate discharged from the secondary causticizing unit 24 enters the freezing unit 26, which includes a low-temperature freezing tank equipped with a coil-type heat exchanger 33 to rapidly reduce the material temperature, causing some impurities in the material to crystallize and precipitate. The outer wall of the low-temperature freezing tank is equipped with a heat insulation layer 27 to reduce heat loss and ensure freezing effect. The frozen material then enters the centrifuge unit 28, which uses a horizontal centrifuge to separate the material. The separated liquid phase enters the recovery tank through the liquid phase outlet for recycling; the solid phase enters the second evaporation unit through the solid phase outlet.

[0034] The solid material entering the second evaporation unit undergoes further evaporation in a reduced-pressure evaporator to remove moisture. The evaporated material is then dried under vacuum to prevent decomposition at high temperatures and ensure product quality. The dried finished product is then stored in a finished product storage tank.

[0035] In this embodiment, the various devices work collaboratively, achieving efficient production of lithium hydroxide through a rational material flow and processing steps. By using calcium oxide to replace some sodium hydroxide, raw material costs are reduced; purification and some reaction processes do not require heating, reducing energy consumption; material recycling improves raw material utilization; and multiple purification and separation steps effectively remove impurities, improving product purity. The entire system has a reasonable structure, is easy to operate, and is suitable for industrial production applications.

[0036] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A lithium hydroxide production system, characterized in that, The system includes a slurry preparation device, a purification and impurity removal device, a filter press, a primary causticizing device, a first evaporation device, a secondary causticizing device, a second evaporation device, a refrigeration device, and a centrifuge device. The outlet of the slurry preparation device is connected to the inlet of the filter press, and the outlet of the filter press is connected to the inlet of the purification and impurity removal device. The filtrate outlet of the purification and impurity removal device is connected to the inlet of the primary causticizing device, and the outlet of the primary causticizing device is connected to both the inlet of the first evaporation device and the inlet of the slurry preparation device. The outlet of the first evaporation device is connected to the inlet of the secondary causticizing device, and the filtrate outlet of the secondary causticizing device is connected to the refrigeration device. The outlet of the refrigeration device is connected to the centrifuge device, and the outlet of the centrifuge device is connected to the second evaporation device. The purification and impurity removal device includes a purification tank. The top of the purification tank has a calcium oxide feeding port, and the bottom of the purification tank has a purification discharge port. From top to bottom, the purification tank contains a crushing component, a pretreatment mechanism, a discharge valve, and a filter screen. A slurry inlet is provided between the pretreatment mechanism and the discharge valve. A first turbidity sensor is provided between the slurry inlet and the discharge valve. The first turbidity sensor is located on the inner wall of the purification tank and is signal-connected to the discharge valve. The slurry inlet is connected to the discharge port of the filter press device.

2. The lithium hydroxide production system according to claim 1, characterized in that, The pulverizing assembly includes a rotating shaft and a blade mesh. The top end of the rotating shaft is connected to the purification tank, and the bottom end of the rotating shaft is connected to the blade mesh. A groove is provided on the inner wall of the purification tank to accommodate the blade mesh, and the blade mesh can rotate within the groove.

3. The lithium hydroxide production system according to claim 1, characterized in that, The pretreatment mechanism includes a spray pipe and a reaction tank. The spray pipe is located above the reaction tank, and the inlet of the spray pipe extends out of the purification tank. The inlet of the spray pipe is connected to a water tank. A second turbidity sensor is installed inside the reaction tank, and an outlet valve is installed at the bottom of the reaction tank. The outlet valve is connected to the signal of the second turbidity sensor.

4. The lithium hydroxide production system according to claim 1, characterized in that, The primary causticizing device includes a reaction vessel with a calcium oxide feed pipe on its side wall and a spiral stirrer inside the reaction vessel; the secondary causticizing device includes a causticizing reaction vessel with a sodium hydroxide feed port at its top.

5. The lithium hydroxide production system according to claim 1, characterized in that, Both the first evaporator and the second evaporator are pressure-reduced evaporators, and the outer walls of the pressure-reduced evaporators are each provided with a heat insulation layer.

6. The lithium hydroxide production system according to claim 1, characterized in that, The filter press includes a plate and frame filter press. The filter residue outlet of the plate and frame filter press is connected to the slag yard conveying channel, and the filtrate outlet is connected to the purification and impurity removal device. The plate and frame filter press is equipped with polypropylene filter plates and matching needle-punched felt filter cloth.

7. The lithium hydroxide production system according to claim 1, characterized in that, The slurry preparation device includes a slurry preparation tank and a stirring assembly disposed in the slurry preparation tank. The top of the slurry preparation tank is provided with a spodumene powder inlet and a water inlet.

8. The lithium hydroxide production system according to claim 1, characterized in that, The refrigeration device includes a low-temperature freezing tank, which is equipped with a coil-type heat exchanger, and the outer wall of the low-temperature freezing tank is provided with a heat insulation layer.

9. The lithium hydroxide production system according to claim 1, characterized in that, The centrifugation device includes a horizontal centrifuge, the liquid phase outlet of which is connected to a recovery tank, and the solid phase outlet is connected to the second evaporation device.

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