A kind of purification device and method of lithium carbonate crude product

Abstract

The present invention relates to the technical field of lithium compound purification, and in particular to a purification device and method for lithium carbonate crude product, comprising a reactor and a driving unit, the reactor comprising a reactor body, an inner barrel and a scraper barrel, the inner barrel is rotatably arranged in the reactor body, and an intermediate cavity is formed between the inner barrel and the reactor body; the scraper barrel is rotatably arranged in the inner barrel, the outer wall of the scraper barrel is in contact with the inner wall of the inner barrel, the driving unit drives the scraper barrel and the inner barrel to rotate, the inner barrel is provided with a storage cavity located in the intermediate cavity, the inner wall of the inner barrel is provided with a feed slot communicating with the storage cavity, the top of the storage cavity is provided with a reflux pipe communicating with the storage cavity and the inner barrel; a gate is provided at one end of the storage cavity facing away from the feed slot, the reactor body is provided with an air inlet and an air outlet, and the bottom of the reactor body is also provided with a discharge port. The present invention does not need to separate the lithium carbonate suspension to the outside of the reactor for separation and purification, and can purify the lithium carbonate precipitate generated by the reaction in the reactor while reacting.

Description

Technical Field

[0001] The invention relates to the technical field of lithium compound purification, and in particular to a purification device and method for crude lithium carbonate. Background Art

[0002] Lithium carbonate is the most important lithium salt among lithium compounds and the main raw material for preparing high-purity lithium compounds. It has broad application prospects in the fields of glass and ceramic manufacturing, medicine, non-ferrous metal smelting, lithium battery electrode materials, etc. Among them, sulfuric acid method, lime roasting method, calcium chloride roasting method, etc. are usually used to complete the preparation of lithium carbonate crude products to meet the needs of related industries.

[0003] At present, the Chinese patent application document with the existing application publication number CN115501830A discloses a lithium compound purification device and method, which sets an auxiliary device. When it is necessary to open the material for discharge, the moving ring is pushed, and the second spring is deformed by force to generate elastic force, and the moving ring loses its restraint on the positioning rod. When the stabilizing rod and the shielding cover are rotated to a certain position in the fixed seat, the moving ring is loosened, the second spring releases the elastic force, and the jack on the surface of the moving ring is sleeved in the positioning rod, and the device can be used. By setting the auxiliary device, it is convenient for the auxiliary equipment to discharge the material, which can effectively reduce the phenomenon of garbage entering the discharge pipe of the equipment, and reduce the blockage caused by the equipment when discharging and cleaning dirt and discharging materials, thereby improving the overall protection of the equipment.

[0004] However, during use, the above-mentioned existing lithium compound purification device needs to discharge the solution containing the lithium compound out of the reactor, filter out the lithium compound, and finally introduce the filtered lithium compound into a drying device for drying. It can be seen that when using the above-mentioned existing lithium compound purification device to purify lithium carbonate (lithium carbonate is a lithium compound) solid, it is necessary to discharge the solution containing lithium carbonate out of the reactor and filter out the crude lithium carbonate. In other words, it can be understood that the existing lithium compound purification device needs to purify the crude lithium carbonate outside the reactor, and purifying lithium carbonate outside the reactor is prone to cause the lithium carbonate to be spilled and lost, and it is also easy to cause other impurities to mix in, affecting the purity of lithium carbonate. Summary of the invention

[0005] The present invention provides a purification device and method for crude lithium carbonate, aiming to solve the technical problem that the existing lithium compound purification device needs to purify the crude lithium carbonate outside the reaction kettle, which easily causes the lithium carbonate to be scattered and lost, and also easily causes other impurities to be mixed in, thus affecting the purity of the lithium carbonate.

[0006] To solve the above problems, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a purification device for crude lithium carbonate, comprising a reactor, a driving unit and a stirring assembly, wherein the reactor comprises a reactor body, the driving unit is arranged on the reactor body, and is used to drive the stirring assembly to rotate in the reactor body; the reactor further comprises an inner barrel and a scraper barrel both located at the periphery of the stirring assembly, the inner barrel is rotatably arranged in the reactor body and an intermediate cavity is formed between the inner barrel and the scraper barrel is rotatably arranged in the inner barrel, and the direction of the scraper barrel and the stirring assembly are opposite, and the scraper barrel is formed by a plurality of scrapers arranged at intervals along the circumference of the inner barrel, the outer wall of the scraper barrel is in contact with the inner wall of the inner barrel, and the scraper barrel is scraped. The drum is driven to rotate by a driving unit and drives the inner drum to rotate, and the inner drum and the scraper drum rotate in opposite directions; at least one storage cavity located in the middle cavity is arranged on the inner drum, and a feed slot communicating with the storage cavity is vertically opened on the inner wall of the inner drum, and the feed slot is arranged at an angle to the scraper on the vertical center line, and the distance between two adjacent scrapers is smaller than the diameter of the feed slot, and a return pipe extending vertically and communicating with the inner drum is arranged on the top of the storage cavity; a gate which can be opened and closed automatically is arranged on the storage cavity, so that the storage cavity and the middle cavity can be communicated; a discharge port is opened at the bottom of the middle cavity.

[0008] When the crude lithium carbonate purification device of the present invention is in use, the driving unit drives the stirring assembly to stir the sodium carbonate powder and the lithium oxide solution or the lithium sulfate solution in the inner barrel. The solution in the inner barrel generates centrifugal force under the stirring action of the stirring assembly, so that the lithium carbonate generated by the reaction in the solution is thrown onto the inner wall of the inner barrel, that is, the lithium carbonate generated by the reaction in the solution in the inner barrel gathers on the inner wall of the inner barrel; because the scraper drum is driven to rotate by the driving unit, and the rotation direction of the scraper drum is opposite to that of the stirring assembly, the lithium carbonate gathered on the inner wall of the inner barrel will enter the storage cavity through the feeding slot and be stored under the action of the lower scraper of the scraper drum, and the liquid entering the storage cavity with the lithium carbonate will flow back to the inner barrel through the reflux pipe; and because the feeding The vertical center line of the notch is set at an angle to the scraper of the scraper barrel, and the distance between two adjacent scrapers is smaller than the diameter of the feed notch. Therefore, the lithium carbonate entering the storage chamber is not easy to flow back into the scraper barrel through the gap between the two scrapers; as the chemical reaction of sodium carbonate powder and lithium oxide solution or lithium sulfate solution continues, more and more lithium carbonate will enter the storage chamber. When the lithium carbonate in the storage chamber is stored to a preset amount, the gate is opened to allow the lithium carbonate in the storage chamber to enter the middle chamber. When the lithium carbonate in the storage chamber enters the middle chamber, the gate is closed, and the lithium carbonate material in the middle chamber is finally discharged and collected from the discharge port. In this cycle, the lithium carbonate precipitate generated by the reaction in the reactor is purified while reacting. It can be seen from this that the purification device for the crude lithium carbonate of the present invention can purify the lithium carbonate precipitate generated by the reaction in the reactor, without separating the lithium carbonate suspension outside the reactor for separation and purification, thereby avoiding the spillage and loss of lithium carbonate caused by purifying the crude lithium carbonate outside the reactor, and easily causing the mixing of other impurities, thereby improving the purity of the crude lithium carbonate.

[0009] Furthermore, an outer cover sealably connected to the inner barrel is provided on the outer wall of the inner barrel at a position corresponding to the feed slot, and guide plates extending vertically and located in the outer cover are provided on opposite sides of the feed slot, and the two ends of the guide plates are respectively sealably connected to the top wall and the bottom wall of the outer cover, and the two guide plates are symmetrical about the center line, and the two guide plates are in an "eight" structure, and a sliding groove is formed between the side wall of the guide plate facing away from the inner barrel and the inner wall of the outer cover, and a discharge port is opened on the side wall of the outer cover facing away from the inner barrel, and a gate is arranged at the position of the discharge port.

[0010] It is beneficial for lithium carbonate materials to enter the storage cavity for storage.

[0011] Furthermore, the gate includes two sliding plates, which are respectively connected to the two sliding grooves in a sealing and sliding manner, and the two sliding plates are used to close the discharge port. One end of the sliding plate is connected to the outer cover through an elastic member, and the elastic member extends along the sliding direction of the sliding plate; when the two sliding plates are sealed and closed, the space enclosed by the two guide plates forms the storage chamber; the other end of the sliding plate is provided with an inclined surface on the side facing the inner barrel, and the inclined surface pushes the sliding plate to retract after the lithium carbonate material stored in the storage chamber from the inner barrel reaches a preset amount.

[0012] The gate can be automatically closed and opened by the extrusion force of the lithium carbonate material.

[0013] Furthermore, the scraper includes an upper scraper and a lower scraper, the lower end of the upper scraper is connected to the top of the lower scraper, the through groove formed by the distance between each adjacent upper scraper is arranged around the circumference of the scraper barrel in a rotation direction opposite to the through groove formed by the distance between each adjacent lower scraper, and the lithium carbonate material in the storage chamber is scraped in by the lower scraper.

[0014] The lithium carbonate thrown to the upper part of the inner wall of the inner barrel can be scraped off by the upper scraper and gathered in the center of the scraper barrel, and the lithium carbonate in the center of the scraper barrel is thrown to the lower part of the inner wall of the inner barrel under the centrifugal force and scraped into the storage chamber by the lower scraper for storage, thereby improving the collection efficiency of the lithium carbonate in the storage chamber.

[0015] Furthermore, an elastic scraper is provided on the outer side wall of one of the lower scrapers, the elastic scraper has the same extension direction as the lower scraper, and the elastic scraper protrudes out of the outer side wall of the lower scraper along the inclined direction of the lower scraper.

[0016] There is no need to wait until the storage chamber is full of lithium carbonate before squeezing the gate to open, thereby shortening the storage time of lithium carbonate in the storage chamber and preventing the lithium carbonate in the storage chamber from returning to the scraper barrel again under the influence of the solution in the scraper barrel.

[0017] Furthermore, an oil chamber connected to the sliding groove is provided between the outer cover and the guide plate; a spiral arm located outside the outer cover is provided on the outer wall of the inner barrel, and a accommodating chamber is opened on the outer wall of the spiral arm facing away from the inner barrel, and a spiral scraper is provided in the accommodating chamber for sliding sealing, and the accommodating chamber is connected to the oil chamber through an oil pipe, so that the end of the spiral scraper facing away from the inner barrel can extend out of the accommodating chamber to scrape off the material on the inner wall of the kettle body.

[0018] The gate and the spiral scraper are linked. When the gate is opened, the spiral scraper extends out of the accommodating cavity on the side facing away from the inner barrel to scrape off the material on the inner wall of the kettle body to avoid the accumulation of lithium carbonate material on the inner wall of the kettle body; when the gate is closed, the spiral scraper retracts into the accommodating cavity on the side facing away from the inner barrel to avoid wear caused by friction between the spiral scraper and the inner wall of the kettle body.

[0019] Furthermore, a plurality of spiral guide arms are arranged on the bottom wall outside the inner barrel, and the plurality of spiral guide arms are arranged at intervals along the circumference of the inner barrel, for guiding the lithium carbonate material entering the intermediate cavity from the storage cavity to converge at the discharge port position at the bottom of the kettle body.

[0020] This is beneficial for the lithium carbonate to gather at the discharge port at the bottom of the kettle body, thereby accelerating the discharge efficiency of the lithium carbonate.

[0021] Furthermore, a drain port is provided at the bottom of the inner barrel, and an outer cylinder and an inner cylinder are provided at the bottom of the drain port, the outer cylinder and the inner cylinder are both fixed on the bottom wall outside the inner barrel, the inner cylinder is located in the outer cylinder, the bottoms of the inner cylinder and the outer cylinder are both open structures, a drain channel is formed between the inner cylinder and the outer cylinder, a filter hole connecting the drain channel and the inner cylinder is provided on the inner cylinder, a lifting cylinder is provided in the inner cylinder, the telescopic end of the lifting cylinder is driven and connected with a sealing head, and the sealing head is used to close the connecting position between the drain port and the filter hole.

[0022] The liquid in the inner barrel is discharged and filtered.

[0023] Furthermore, a driving gear is fixed on the top of the stirring assembly, a passive gear meshing with the driving gear is rotatably provided on the kettle body, a first inner gear ring meshing with the passive gear is fixed on the inner wall of the top end of the scraper barrel; an outer gear ring is fixed on the outer wall of the top end of the scraper barrel, a second inner gear ring is fixed on the inner wall of the top end of the inner barrel, and an intermediate gear meshing with the first inner gear ring and the second inner gear ring is also provided on the kettle body.

[0024] The inner barrel, the stirring assembly and the scraper barrel can be rotated simultaneously by using one driving unit, which saves the driving structure and thus achieves the effect of cost saving.

[0025] In a second aspect, the present invention provides a method for purifying a crude lithium carbonate product, wherein the crude lithium carbonate product is purified using the purification device of the present invention, and the method comprises the following steps:

[0026] S1. Add sodium carbonate powder and lithium oxide solution or lithium sulfate solution into the inner barrel;

[0027] S2, start the driving unit, drive the stirring assembly to stir the solution in the inner barrel, and drive the inner barrel and the scraper barrel to rotate relative to each other, so that the lithium carbonate generated by the reaction in the inner barrel is gathered toward the inner wall of the inner barrel under the centrifugal force of the solution, and the lithium carbonate gathered on the inner wall of the inner barrel is scraped into the storage chamber for storage under the action of the scraper of the scraper barrel, and the liquid entering the storage chamber with the lithium carbonate flows back to the inner barrel through the reflux pipe;

[0028] S3. When the storage cavity is filled with lithium carbonate, the scraper will squeeze the lithium carbonate material in the storage cavity to force the gate to open, so that the lithium carbonate material in the storage cavity enters the middle cavity;

[0029] S4, introducing hot air flow into the middle cavity through the air inlet, the hot air flow heats and dries the lithium carbonate material entering the middle cavity from the material storage cavity, and then is discharged through the air outlet;

[0030] S5. The lithium carbonate material in the middle cavity is heated and dried to form a crude lithium carbonate product, which falls into the bottom of the kettle body and is discharged from the discharge port, thereby achieving the purification of the crude lithium carbonate product.

[0031] The method for purifying crude lithium carbonate of the present invention uses the device for purifying crude lithium carbonate of the present invention to purify crude lithium carbonate, so that the method for purifying crude lithium carbonate of the present invention can purify the lithium carbonate precipitate generated by the reaction in the reactor in the reactor, without the need to separate the lithium carbonate suspension outside the reactor for separation and purification, and without the need to transport and dry the lithium carbonate to avoid the loss of lithium carbonate and the mixing of other impurities, thereby improving the purity of the crude lithium carbonate.

[0032] The beneficial effects of the present invention are as follows: the present invention can purify the lithium carbonate precipitate generated by the reaction in the reactor, without the need to separate the lithium carbonate suspension outside the reactor for separation and purification, and without the need to transport and dry the lithium carbonate to avoid the loss of lithium carbonate and the mixing of other impurities, thereby improving the purity of the crude lithium carbonate. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a structural schematic diagram of a purification device for crude lithium carbonate of the present invention;

[0034] Figure 2 It is a schematic diagram of the structure of the embodiment of the present invention when the kettle body is removed;

[0035] Figure 3This is a schematic diagram of the structure of the connection between the driving unit and the stirring assembly according to an embodiment of the present invention;

[0036] Figure 4 This is a schematic diagram of the structure of an inner barrel according to an embodiment of the present invention;

[0037] Figure 5 for Figure 4 A schematic diagram of the structure from another angle;

[0038] Figure 6 for Figure 5 A schematic diagram of the structure from another angle;

[0039] Figure 7 This is a bottom view of an inner barrel according to an embodiment of the present invention;

[0040] Figure 8 This is a schematic diagram of the structure of a scraper barrel according to an embodiment of the present invention;

[0041] Fig. 9 This is a front view of a scraper barrel according to an embodiment of the present invention;

[0042] Fig.10 for Fig. 9 Sectional view at AA in the middle;

[0043] Fig.11 for Fig. 9 Sectional view at the middle BB;

[0044] Fig.12 It is a front view of a purification device for crude lithium carbonate of the present invention;

[0045] Fig.13 for Fig.12 Sectional view at CC;

[0046] Fig.14 for Fig.12 Sectional view at DD in the middle;

[0047] Fig.15 for Fig.14 Schematic diagram of the enlarged structure at E in the middle;

[0048] Fig.16 for Fig.12 A schematic diagram of the structure from another angle;

[0049] Fig.17 for Fig.16 Cross-sectional view at FF;

[0050] Fig.18 for Figure 2 A top view of

[0051] Fig.19 It is a structural schematic diagram of a sliding plate related to an embodiment of the present invention;

[0052] Fig. 20 This is a schematic diagram of the structure of the embodiment of the present invention when two sliding plates are in a closed state;

[0053] Fig.21 The present invention is a schematic structural diagram of the connection between the lifting cylinder and the sealing head according to an embodiment of the present invention.

[0054] Reference numerals in the accompanying drawings:

[0055] 1. Reactor; 10. Reactor body; 101. Reactor body; 102. Cover plate; 1021. Feed port; 103. Air inlet; 104. Air outlet; 12. Inner barrel; 120. Outer cover; 1201. Sliding groove; 121. Discharge port; 122. Reflux pipe; 123. Spiral arm; 124. Accommodating chamber; 1240. Spiral scraper; 125. Drain port; 1250. Outer barrel; 1251. Inner barrel; 1252. Drain channel; 126. Filter hole; 127. Spiral guide arm; 13. Scraper barrel; 130. Upper scraper; 131. Lower scraper; 1310. Scraper plate; 1311. Return spring; 1312. Long groove; 132. Upper ring; 1 320, first inner gear ring; 1321, outer gear ring; 133, middle ring; 134, lower ring; 135, storage cavity; 136, guide plate; 1361, guide surface; 1362, protrusion; 1363, oil cavity; 137, feed slot; 138, through slot; 139, oil pipe; 2, drive unit; 3, stirring assembly; 30, stirring shaft; 301, driving gear; 302, driven gear; 4, middle gear; 5, second inner gear ring; 6, middle cavity; 60, discharge port; 7, gate; 70, sliding plate; 701, inclined surface; 71, blade portion; 72, annular groove; 720, square sealing ring; 73, elastic member; 8, lifting cylinder; 80, sealing head. DETAILED DESCRIPTION

[0056] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0057] In the description of the present invention, it is necessary to understand that the orientations or positional relationships indicated by terms such as "width", "up", "down", "front", "back", "top" and "bottom" are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0058] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", and "set" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0059] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0060] Please refer to Figure 1-Figure 21 The present invention provides a purification device for crude lithium carbonate, comprising a reactor 1, a driving unit 2 and a stirring assembly 3. The reactor 1 comprises a reactor body 10, an inner barrel 12 and a scraper barrel 13. The reactor body 10 comprises a reactor body 101 and a cover plate 102. The cover plate 102 is used to seal the upper port of the reactor body 101. The inner barrel 12 is rotatably arranged in the reactor body 10, and an intermediate cavity 6 is formed between the inner barrel 12 and the reactor body 10. The scraper barrel 13 is rotatably arranged in the inner barrel 12. A feed port 1021 is also arranged on the top of the reactor body 10. The feed port 1021 is used to add sodium carbonate powder and lithium oxide solution or lithium sulfate solution into the inner barrel 12.

[0061] Reference Figure 2 , Figure 8 , Fig. 9 , Fig.10 and Fig.11The scraper barrel 13 is formed by a plurality of scrapers that are interconnected and spaced apart along the circumference of the inner barrel 12; each scraper includes an upper scraper 130 and a lower scraper 131; the bottom end of the upper scraper 130 is connected to the top end of the lower scraper 131; the top end surface of each upper scraper 130 is connected and fixed by an upper ring 132; the inner ring wall and the outer ring wall of the upper ring 132 are respectively the top inner wall and the top outer wall of the scraper barrel 13; the outer diameter of the upper ring 132 is smaller than the outer diameter of the circle formed by the plurality of upper scrapers 130 along the circumference of the inner barrel 12; the bottom end surface of each upper scraper 130 is connected and fixed to the upper surface of the middle ring 133; the outer diameter of the middle ring 133 is the same as the outer diameter of the upper ring 132; the top end surface of each lower scraper 131 is connected and fixed to the lower surface of the middle ring 133; the bottom end surface of each lower scraper 131 is connected and fixed by a lower ring 134; the outer diameter of the lower ring 134 is the same as the outer diameter of the middle ring 133. Fig.10 and Fig.11 The rotation direction of the through groove 138 formed by the distance between each two adjacent upper scrapers 130 around the circumference of the scraper barrel 13 is opposite to the rotation direction of the through groove 138 formed by the distance between each two adjacent lower scrapers 131 around the circumference of the scraper barrel 13. Of course, referring to Figure 2 The outer wall of the scraper tube 13 is in contact with the inner wall of the inner barrel 12 .

[0062] Reference Figure 2 , Figure 3 , Fig.13 and Fig.18, the scraper barrel 13 and the stirring assembly 3 rotate in opposite directions, the stirring assembly 3 rotates in the scraper barrel 13, the scraper barrel 13 is driven to rotate by the driving unit 2, and the inner barrel 12 is driven to rotate by the scraper barrel 13, and the inner barrel 12 and the scraper barrel 13 rotate in opposite directions. Specifically, the driving unit 2 is arranged on the kettle body 10, and the driving unit 2 uses a driving motor. The driving unit 2 is fixed on the cover plate 102 and is located outside the kettle body 101. The output end of the driving unit 2 is connected to the stirring assembly 3 located in the scraper barrel 13, so that the stirring assembly 3 can be driven to rotate in the kettle body 10 by starting the driving unit 2. A driving gear 301 is fixed on the top of the stirring shaft 30 of the stirring assembly 3, a passive gear 302 meshing with the driving gear 301 is rotatably provided on the cover plate 102 of the kettle body 10, a first inner gear ring 1320 meshing with the passive gear 302 is fixed on the top inner wall of the scraper barrel 13; an outer gear ring 1321 is fixed on the top outer wall of the scraper barrel 13, a second inner gear ring 5 is fixed on the top inner wall of the inner barrel 12, and an intermediate gear 4 meshing with the first inner gear ring 1320 and the second inner gear ring 5 is also provided on the kettle body 10. For example, when the driving unit 2 drives the stirring assembly 3 to rotate clockwise, the driving gear 301 drives the driven gear 302 to rotate counterclockwise, and the driven gear 302 drives the scraper barrel 13 to rotate counterclockwise, and the counterclockwise rotation of the scraper barrel 13 drives the intermediate gear 4 to rotate clockwise, and the clockwise rotation of the intermediate gear 4 drives the inner barrel 12 to rotate clockwise, so that the scraper barrel 13 and the stirring assembly 3 can be turned in opposite directions, and the inner barrel 12 and the scraper barrel 13 can be turned in opposite directions. Therefore, it can be known that the driving structure of this embodiment can use one driving unit 2 to simultaneously realize the rotation of the inner barrel 12, the stirring assembly 3 and the scraper barrel 13, without the need to use multiple driving structures, thereby achieving the effect of cost saving.

[0063] In addition, refer to Figure 1 , Figure 2 , Figure 4 , Figure 5 and Figure 12-Figure 15, the inner barrel 12 is provided with at least one storage cavity 135 located in the middle cavity 6, and the storage cavity 135 is provided at the lower part of the outer wall of the inner barrel 12, so that the lithium carbonate material in the storage cavity 135 is scraped into by the lower scraper 131; a feed slot 137 corresponding to and communicating with the storage cavity 135 is vertically opened on the inner wall of the inner barrel 12, and the feed slot 137 is arranged at an angle with the scraper on the vertical center line, and the distance between two adjacent scrapers is smaller than the diameter of the feed slot 137, and a reflux pipe 122 extending vertically is provided on the top of the storage cavity 135, and the opposite ends of the reflux pipe 122 are respectively communicated with the storage cavity 135 and the inner barrel 12; An automatically closing gate 7 is provided at one end of the cavity 135 facing away from the feed slot 137. When the lithium carbonate material stored in the storage cavity 135 from the inner barrel 12 reaches a preset amount, the gate 7 is squeezed to open automatically. An air inlet 103 and an air outlet 104, both of which are connected to the middle cavity 6, are provided on the kettle body 10. The air inlet 103 is used to introduce hot air flow into the middle cavity 6, and the hot air flow can dry the lithium carbonate material entering the middle cavity 6 from the storage cavity 135. The air outlet 104 is used to discharge the hot air flow. A discharge port 60 connected to the middle cavity 6 is also provided at the bottom of the kettle body 10 for discharging and collecting the dried crude lithium carbonate.

[0064] In summary, when the purification device for crude lithium carbonate of the present invention is in use, the driving unit 2 drives the stirring assembly 3 to stir the sodium carbonate powder and the lithium oxide solution or the lithium sulfate solution in the inner barrel 12. The solution in the inner barrel 12 generates centrifugal force under the stirring action of the stirring assembly 3, so that the lithium carbonate generated by the reaction in the solution is thrown onto the inner wall of the inner barrel 12, that is, the lithium carbonate generated by the reaction in the solution in the inner barrel 12 is gathered on the inner wall of the inner barrel 12; since the rotation direction of the scraper barrel 13 is opposite to that of the stirring assembly 3, the lithium carbonate gathered on the inner wall of the inner barrel 12 will enter the storage chamber 135 through the feed notch 137 under the action of the lower scraper 131 of the scraper barrel 13 for storage, and the liquid entering the storage chamber 135 with the lithium carbonate will flow back to the inner barrel 12 through the reflux pipe 122; and since the vertical center line of the feed notch 137 is set at an angle to the scraper of the scraper barrel 13, and the relative The distance between two adjacent scrapers is smaller than the diameter of the feed slot 137, so it is not easy for the lithium carbonate entering the storage chamber 135 to flow back into the scraper barrel 13 through the gap between the two scrapers; as the chemical reaction continues, more and more lithium carbonate will enter the storage chamber 135. When the lithium carbonate in the storage chamber 135 is stored to a preset amount, the extrusion force of the lithium carbonate material on the gate 7 will force the gate 7 to open automatically, so that the lithium carbonate in the storage chamber 135 enters the middle chamber 6. When the lithium carbonate in the storage chamber 135 enters the middle chamber 6, the gate 7 closes automatically, and the lithium carbonate material is heated and dried under the action of the hot air flow in the middle chamber 6, thereby forming a crude lithium carbonate product; after being dried, the crude lithium carbonate product will fall to the bottom of the kettle body 10, and finally be discharged and collected from the discharge port 60, so as to realize the reaction and purification of the lithium carbonate precipitate generated by the reaction in the reactor 1. It can be seen that the purification device for crude lithium carbonate of the present invention can purify the lithium carbonate precipitate generated by the reaction in the reactor 1, without separating the lithium carbonate suspension outside the reactor 1 for separation and purification, and without transporting and drying the lithium carbonate to avoid the loss of lithium carbonate and the mixing of other impurities, thereby improving the purity of the crude lithium carbonate.

[0065] In addition, during the process of purifying the crude lithium carbonate, the purification device of the crude lithium carbonate of the present invention does not need to stop the machine for standing and then discharge the lithium carbonate suspension for filtering and purification, and does not need to transport the lithium carbonate to a drying device for drying, thereby reducing the operation process and improving the purification efficiency of the crude lithium carbonate.

[0066] It should be noted that, since the lower part of the scraper barrel 13 is formed by multiple lower scrapers 131, the upper part of the scraper barrel 13 is formed by multiple lower scrapers 131, and the through grooves 138 formed by the distance between each adjacent upper scraper plates 130 are arranged around the scraper barrel 13 in a rotation direction opposite to the rotation direction of the through grooves 138 formed by the distance between each adjacent lower scraper plates 131. Therefore, the lithium carbonate thrown to the upper part of the inner wall of the inner barrel 12 is scraped off by the upper scrapers 130 and gathered in the center of the scraper barrel 13, and the lithium carbonate gathered in the center of the scraper barrel 13 is thrown to the lower part of the inner wall of the inner barrel 12 under the centrifugal force of the solution and is scraped into the storage chamber 135 for storage through the lower scrapers 131, and this cycle is repeated to improve the collection efficiency of the lithium carbonate in the storage chamber 135.

[0067] In one embodiment, referring to Figure 2 , Figure 4-Figure 6 , Figure 12-Figure 15 , Fig.19 and Fig. 20 An outer cover 120 sealed and connected to the inner barrel 12 is provided on the outer wall of the inner barrel 12 at a position corresponding to the feed slot 137, and guide plates 136 extending vertically and located in the outer cover 120 are provided on opposite sides of the feed slot 137, and the two ends of the guide plate 136 are respectively sealed and connected to the top wall and the bottom wall of the outer cover 120, and the two guide plates 136 are symmetrical about the vertical center line of the feed slot 137, and the two guide plates 136 are in an "eight" structure. The large end of the "eight" structure is close to the scraper barrel 13, and the small end of the "eight" structure is facing away from the scraper barrel 13. The surfaces of the two guide plates 136 facing each other are guide surfaces 1361. The side surfaces of the guide plates 136 facing away from the respective guide surfaces 1361 are provided with protrusions 1362 located outside the outer wall of the inner barrel 12. A sliding groove 1201 is formed between the side wall of the protrusion 1362 facing away from the inner barrel 12 and the inner wall of the outer cover 120. The side wall of the outer cover 120 facing away from the inner barrel 12 is provided with a discharge port 121. The gate 7 includes two sliding plates 70. The two sliding plates 70 are respectively connected to the two sliding grooves 1201 in a sealing and sliding manner. A square sealing ring 720 is sleeved in the annular groove 72 on the sliding plate 70 to achieve the gap sealing between the sliding plate 70 and the sliding groove 1201. The two sliding plates 70 are used to close the discharge port 121. Of course, one end of the sliding plate 70 is connected to the outer cover 120 through an elastic member 73. The elastic member 73 is a spring. The elastic member 73 extends along the sliding direction of the sliding plate 70. When the two sliding plates 70 are sealed and closed, the space enclosed by the two guide plates 136 forms the above-mentioned storage chamber 135. In addition, an inclined surface 701 is provided on the side of the other end of the sliding plate 70 facing the inner barrel 12, and the inclined surface 701 pushes the sliding plate 70 to retract when the lithium carbonate material stored in the storage chamber 135 from the inner barrel 12 reaches a preset amount.

[0068] As can be seen from the above, when the inner barrel 12 rotates clockwise under the drive of the driving unit 2, the solution in the inner barrel 12 generates centrifugal force under the stirring action of the stirring assembly 3, so that the lithium carbonate generated by the reaction in the solution is thrown onto the inner wall of the inner barrel 12, that is, the lithium carbonate generated by the reaction in the solution of the inner barrel 12 gathers on the inner wall of the inner barrel 12, and at the same time, the scraper barrel 13 rotates counterclockwise, and the lower scraper plate 131 of the scraper barrel 13 scrapes the lithium carbonate into the storage chamber 135 along the inner wall of the inner barrel 12. When the lithium carbonate is fully stored in the storage chamber 135, as the solution in the inner barrel 12 is continuously reacted, the lithium carbonate generated by the reaction in the solution of the inner barrel 12 is gathered on the inner wall of the inner barrel 12. When lithium carbonate is generated and continues to enter the storage chamber 135, the lithium carbonate in the storage chamber 135 will squeeze the inclined surface 701 of the sliding plate 70, forcing the sliding plate 70 to retract, so that the two sliding plates 70 slide back to back, achieving the effect of automatically opening the gate 7, thereby allowing the lithium carbonate in the storage chamber 135 to enter the middle chamber 6; after the lithium carbonate in the storage chamber 135 enters the middle chamber 6, the sliding plate 70 is reset under the elastic action of the elastic member 73, so that the two sliding plates 70 slide toward each other, achieving the effect of automatically closing the gate 7.

[0069] In another embodiment, the elastic member 73 may also be replaced by a drive cylinder, which is used to drive the sliding plate 70 to slide horizontally along the sliding groove 1201. That is, one sliding plate 70 is driven by one drive cylinder. Specifically, when the elastic member 73 is replaced by the drive cylinder, a pressure sensor (not shown) needs to be set on the guide surface 1361. By setting a preset pressure threshold of the pressure sensor, when the pressure of the lithium carbonate in the storage chamber 135 acting on the guide surface 1361 is greater than the preset pressure threshold, the driving cylinder controls the sliding plate 70 to retract, so that the two sliding plates 70 slide back to back, so as to achieve the effect of automatically opening the gate 7, so that the lithium carbonate in the storage chamber 135 enters the middle chamber 6; after the lithium carbonate in the storage chamber 135 enters the middle chamber 6, the pressure of the lithium carbonate in the storage chamber 135 acting on the guide surface 1361 is less than the preset pressure threshold of the pressure sensor, and the driving cylinder drives the sliding plate 70 to reset, so that the two sliding plates 70 slide toward each other, so as to achieve the effect of automatically closing the gate 7.

[0070] It should be noted that, refer to Fig.15 and Fig. 20 The inclined surface 701 on the sliding plate 70 forms a blade portion 71 on the end of the sliding plate 70 that faces away from the sliding groove 1201. In this way, when the two sliding plates 70 slide back to back to open and allow the lithium carbonate in the storage chamber 135 to enter the middle chamber 6, the blade portion 71 can disperse the lithium carbonate material in a sticky state, which is beneficial for the lithium carbonate material to enter the middle chamber 6 and be dried by the hot air flow.

[0071] In order to prevent the gate 7 from being squeezed open after the storage chamber 135 is filled with lithium carbonate, an elastic scraper is provided on the outer wall of one or more lower scrapers 131. The elastic scraper extends in the same direction as the lower scraper 131 and protrudes out of the outer wall of the lower scraper 131 along the inclined direction of the lower scraper 131. Figure 8 , Fig.12 , Fig.14 and Fig.15 The elastic scraper includes a scraper plate 1310 and a return spring 1311. The scraper plate 1310 is connected and fixed to the outer wall of the lower scraper plate 131 through the return spring 1311. A long groove 1312 is provided on the outer wall of the lower scraper plate 131. The long groove 1312 extends along the axial direction of the lower scraper plate 131. The scraper plate 1310 is horizontally slidably adapted to the long groove 1312. The first side of the scraper plate 1310 is slidably inserted into the long groove 1312. The second side of the scraper plate 1310 is located outside the long groove 1312. The long groove 1312 faces inward. The surface of the barrel 12 is a connecting surface, and the two ends of the first side of the scraper plate 1310 are fixed with a return spring 1311, and one end of the return spring 1311 facing away from the scraper plate 1310 is connected and fixed to the connecting surface. When the scraper plate 1310 contacts the inner wall of the inner barrel 12, the return spring 1311 is in a compressed state. When the scraper plate 1310 rotates to the position of the feed slot 137, the return spring 1311 is reset, so that the second side of the scraper plate 1310 extends into the storage cavity 135 to squeeze the lithium carbonate, forcing the sliding plate 70 to retract, thereby opening the gate 7. It can be seen that by squeezing the lithium carbonate in the storage cavity 135 through the elastic scraper, there is no need to wait until the storage cavity 135 is full of lithium carbonate before squeezing the gate 7 to open, which shortens the storage time of lithium carbonate in the storage cavity 135 and prevents the lithium carbonate in the storage cavity 135 from returning to the scraper barrel 13 again under the influence of the solution in the scraper barrel 13.

[0072] Since the inner barrel 12 of the crude lithium carbonate purification device of the present invention is in a rotating state during operation, some lithium carbonate will be thrown onto the inner wall of the kettle body 10 during the process of lithium carbonate in the storage cavity 135 entering the intermediate cavity 6 under the centrifugal force of the rotation of the inner barrel 12. For this reason, a spiral scraper assembly located outside the outer cover 120 is provided on the outer wall of the inner barrel 12, and the lithium carbonate material on the inner wall of the kettle body 10 is scraped off by the spiral scraper assembly to prevent the lithium carbonate material from accumulating on the inner wall of the kettle body 10 and affecting the collection and purification of lithium carbonate.

[0073] Specifically, refer to Figure 2 , Figure 4 , Figure 5The spiral scraper assembly includes a spiral arm 123 and a spiral scraper 1240. The spiral arm 123 is arranged on the outer wall of the inner barrel 12 and outside the outer cover 120. The outer wall of the spiral arm 123 facing away from the inner barrel 12 is provided with a receiving cavity 124. The spiral scraper 1240 is slidingly sealed and arranged in the receiving cavity 124. In addition, referring to Figure 4 , Figure 5 , Fig.12 and Fig.15 An oil chamber 1363 communicating with the sliding groove 1201 is provided between the outer cover 120 and the guide plate 136, and the accommodating chamber 124 is connected with the oil chamber 1363 through the oil pipe 139, so that the spiral scraper 1240 can extend out of the accommodating chamber 124 on the side facing away from the inner barrel 12 to scrape off the lithium carbonate material on the inner wall of the kettle body 10. It can be understood that when the gate 7 is opened, that is, the two sliding plates 70 slide back to back, the oil pressure in the oil chamber 1363 will increase, forcing the hydraulic oil in the oil chamber 1363 to enter the accommodating chamber 124 through the oil pipe 139, thereby driving the spiral scraper 1240 to extend out of the accommodating chamber 124 on the side facing away from the inner barrel 12 to scrape off the lithium carbonate material on the inner wall of the kettle body 10; when the gate 7 is closed, that is, the two sliding plates 70 slide towards each other and close, the oil pressure in the oil chamber 1363 decreases, and the hydraulic oil in the accommodating chamber 124 enters the oil chamber 1363, causing the spiral scraper 1240 to retract into the accommodating chamber 124, thereby avoiding the friction between the spiral scraper 1240 and the inner wall of the kettle body 10 and affecting the rotation of the inner barrel 12, and at the same time, it can also avoid the spiral scraper 1240 from being damaged by friction. In summary, when the gate 7 is opened, the spiral scraper 1240 extends out of the accommodating chamber 124 to scrape the materials on the inner wall of the kettle body 10; when the gate 7 is closed, the spiral scraper 1240 retracts into the accommodating chamber 124, realizing the linkage between the gate 7 and the spiral scraper 1240.

[0074] It should be noted that the sealing between the spiral scraper 1240 and the accommodating chamber 124 can be achieved by using a sealing ring, which is similar to the sealing structure between the piston rod and the cylinder body of a hydraulic cylinder and is not described here.

[0075] In addition, refer to Figure 7 A plurality of spiral guide arms 127 are arranged on the bottom wall outside the inner barrel 12, and the plurality of spiral guide arms 127 are arranged at intervals along the circumference of the inner barrel 12. The spiral guide arms 127 are mainly used to guide the carbonated material entering the intermediate cavity from the storage cavity to gather at the discharge port 60 at the bottom of the kettle body 10, so that lithium carbonate can be gathered at the discharge port 60 at the bottom of the kettle body 10, thereby accelerating the discharge efficiency of lithium carbonate. Of course, a powder delivery pump can be connected to the discharge port 60, and the powder delivery pump is used to discharge and collect the crude lithium carbonate.

[0076] Reference Fig.12 , Fig.13 , Fig.16 , Fig.17 and Fig.21 A drainage port 125 is provided at the bottom of the inner barrel 12, and an outer cylinder 1250 and an inner cylinder 1251 are provided at the bottom of the drainage port 125. The outer cylinder 1250 and the inner cylinder 1251 are both fixed on the bottom wall outside the inner barrel 12, and the inner cylinder 1251 is located in the outer cylinder 1250. The bottoms of the inner cylinder 1251 and the outer cylinder 1250 are both open structures. A drainage channel 1252 is formed between the inner cylinder 1251 and the outer cylinder 1250. A filtering hole 126 connecting the drainage channel 1252 and the inner cylinder 1251 is provided on the inner cylinder 1251. A lifting cylinder 8 is provided in the inner cylinder 1251. The telescopic end of the lifting cylinder 8 is driven and connected with a sealing head 80. The sealing head 80 is used to close the connecting position between the drainage port 125 and the filtering hole 126. Specifically, it can be understood that during the operation of the crude lithium carbonate purification device of the present invention, the sealing head 80 closes the connection position between the drain port 125 and the filter hole 126; after the liquid in the inner barrel 12 needs to be discharged, the lifting cylinder 8 will be started to drive the sealing head 80 to descend, so that the drain port 125 is connected with the filter hole 126, thereby discharging the liquid in the inner barrel 12 and achieving the filtering effect.

[0077] The working principle of the present invention is:

[0078] First, sodium carbonate powder and lithium oxide solution or lithium sulfate solution are added into the inner barrel 12; then, the driving unit 2 is started to drive the stirring component 3 to stir the solution in the inner barrel 12, and the stirring component 3 rotates to drive the scraper barrel 13 and the inner barrel 12 to rotate. Under the stirring action of the stirring component 3, the solution in the inner barrel 12 generates centrifugal force, so that the lithium carbonate generated by the reaction in the solution is thrown onto the inner wall of the inner barrel 12, that is, the lithium carbonate generated by the reaction in the solution in the inner barrel 12 is gathered on the inner wall of the inner barrel 12, and the lithium carbonate gathered on the inner wall of the inner barrel 12 is scraped by the lower scraper 131 of the scraper barrel 13. , is scraped off and stored in the storage chamber 135, and the liquid entering the storage chamber 135 along with the lithium carbonate flows back to the inner barrel 12 through the reflux pipe 122; when the lithium carbonate stored in the storage chamber 135 reaches a preset amount, the elastic scraper will squeeze the lithium carbonate material in the storage chamber 135 to force the gate 7 to open, so that the lithium carbonate material in the storage chamber 135 enters the middle chamber 6; the lithium carbonate material entering the middle chamber 6 is heated and dried by the hot air flow to form a crude lithium carbonate product; finally, the crude lithium carbonate falls into the bottom of the kettle body 10 and is discharged from the discharge port 60, thereby realizing the purification of the crude lithium carbonate product.

[0079] The present invention also provides a method for purifying crude lithium carbonate, wherein the crude lithium carbonate is purified by using the purification device of the present invention, and the method comprises the following steps:

[0080] S1, adding sodium carbonate powder and lithium oxide solution or lithium sulfate solution into the inner barrel 12;

[0081] S2, start the driving unit 2, drive the stirring assembly 3 to stir the solution in the inner barrel 12, and drive the inner barrel 12 and the scraper barrel 13 to rotate relative to each other, so that the lithium carbonate generated by the reaction in the inner barrel 12 is gathered toward the inner wall of the inner barrel 12 under the centrifugal force of the solution, and the lithium carbonate gathered on the inner wall of the inner barrel 12 is scraped into the storage chamber 135 for storage under the action of the scraper of the scraper barrel 13, and the liquid entering the storage chamber 135 with the lithium carbonate flows back to the inner barrel 12 through the reflux pipe 122;

[0082] S3, when the storage chamber 135 is filled with lithium carbonate, the scraper will squeeze the lithium carbonate material in the storage chamber 135 to force the gate 7 to open, so that the lithium carbonate material in the storage chamber 135 enters the middle chamber 6;

[0083] S4, hot air is introduced into the middle chamber 6 through the air inlet 103, the hot air heats and dries the lithium carbonate material that enters the middle chamber 6 from the material storage chamber 135, and then is discharged through the air outlet 104;

[0084] S5. The lithium carbonate material in the middle cavity 6 is heated and dried to form a crude lithium carbonate product, which falls into the bottom of the kettle body 10 and is discharged from the discharge port 60, thereby achieving the purification of the crude lithium carbonate product.

[0085] The method for purifying crude lithium carbonate of the present invention can purify the lithium carbonate precipitate generated by the reaction in the reactor 1 in the reactor 1, without separating the lithium carbonate suspension to the outside of the reactor 1 for separation and purification, and without transporting and drying the lithium carbonate to avoid the loss of lithium carbonate and the mixing of other impurities, thereby improving the purity of the crude lithium carbonate.

[0086] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A purification device for crude lithium carbonate, comprising a reaction kettle (1), a driving unit (2) and a stirring assembly (3), wherein the reaction kettle (1) comprises a kettle body (10), and the driving unit (2) is arranged on the kettle body (10) and is used to drive the stirring assembly (3) to rotate in the kettle body (10); characterized in that: The reaction kettle (1) further comprises an inner barrel (12) and a scraper barrel (13) both of which are located on the periphery of the stirring assembly (3); the inner barrel (12) is rotatably arranged in the kettle body (10) and an intermediate cavity (6) is formed between the inner barrel (12); the scraper barrel (13) is rotatably arranged in the inner barrel (12), and the direction of rotation of the scraper barrel (13) and the stirring assembly (3) are opposite; the scraper barrel (13) is formed by a plurality of scrapers arranged at intervals along the circumference of the inner barrel (12); the outer wall of the scraper barrel (13) is in contact with the inner wall of the inner barrel (12); the scraper barrel (13) is driven to rotate by the driving unit (2) and drives the inner barrel (12) to rotate; the inner barrel (12) and the scraper barrel (13) have opposite directions of rotation; at least one scraper barrel (13) is provided on the inner barrel (12) and is located in the intermediate cavity (6). A material storage chamber (135) is provided on the inner wall of the inner barrel (12), a feed slot (137) communicating with the material storage chamber (135) is vertically provided, the feed slot (137) is arranged at an angle with the scraper on the center line in the vertical direction, the distance between two adjacent scrapers is smaller than the diameter of the feed slot (137), and a return pipe (122) extending vertically and communicating with the inner barrel (12) is provided on the top of the material storage chamber (135); a gate (7) capable of opening and closing automatically is provided on the material storage chamber (135), so that the material storage chamber (135) and the middle chamber (6) can be communicated; a discharge port (60) is provided at the bottom of the middle chamber (6); a discharge port (60) communicating with the inner barrel (12) is provided on the outer wall of the inner barrel (12) at a position corresponding to the feed slot (137). The outer cover (120) is sealed and connected, and guide plates (136) extending vertically and located in the outer cover (120) are arranged on opposite sides of the feed slot (137). The two ends of the guide plates (136) are respectively sealed and connected to the top wall and the bottom wall of the outer cover (120). The two guide plates (136) are symmetrical about the center line. The two guide plates (136) are in an "eight" structure. A sliding groove (1201) is formed between the side wall of the guide plate (136) facing away from the inner barrel (12) and the inner wall of the outer cover (120). A discharge port (121) is opened on the side wall of the outer cover (120) facing away from the inner barrel (12). The gate (7) is arranged at the position of the discharge port (121); the gate (7) includes two sliding The two sliding plates (70) are respectively connected to the two sliding grooves (1201) in a sealing and sliding manner. The two sliding plates (70) are used to close the discharge port (121). One end of the sliding plate (70) is connected to the outer cover (120) through an elastic member (73). The elastic member (73) extends along the sliding direction of the sliding plate (70). When the two sliding plates (70) are sealed and closed, the space enclosed by the two guide plates (136) forms the storage chamber (135). The other end of the sliding plate (70) is provided with an inclined surface (701) on the side facing the inner barrel (12). The inclined surface (701) pushes the sliding plate (70) to retract when the lithium carbonate material stored in the storage chamber (135) from the inner barrel (12) reaches a preset amount.An oil chamber (1363) communicating with the sliding groove (1201) is provided between the outer cover (120) and the guide plate (136); a spiral arm (123) located outside the outer cover (120) is provided on the outer wall of the inner barrel (12); a receiving chamber (124) is provided on the outer wall of the spiral arm (123) facing away from the inner barrel (12); a spiral scraper (1240) is provided in a sliding seal in the receiving chamber (124); the receiving chamber (124) is communicated with the oil chamber (1363) via an oil pipe (139), so that an end of the spiral scraper (1240) facing away from the inner barrel (12) can extend out of the receiving chamber (124) to scrape off materials on the inner wall of the kettle body (10).

2. The purification device for crude lithium carbonate according to claim 1, characterized in that: The scrapers each comprise an upper scraper (130) and a lower scraper (131); the lower end of the upper scraper (130) is connected to the top end of the lower scraper (131); the through groove (138) formed by the distance between adjacent upper scrapers (130) is arranged around the circumference of the scraper barrel (13) in a direction opposite to the through groove (138) formed by the distance between two adjacent lower scrapers (131) in a direction opposite to the direction of the through groove (138) formed by the distance between two adjacent lower scrapers (131) in a direction opposite to the direction of the through groove (138) arranged around the circumference of the scraper barrel (13); the lithium carbonate material in the storage chamber (135) is scraped into the storage chamber (135) by the lower scraper (131).

3. The purification device for crude lithium carbonate according to claim 2, characterized in that, An elastic scraper is provided on the outer side wall of one of the lower scrapers (131); the elastic scraper extends in the same direction as the lower scraper (131); and the elastic scraper protrudes outside the outer side wall of the lower scraper (131) along the inclined direction of the lower scraper (131).

4. The purification device for crude lithium carbonate according to claim 1, characterized in that: A plurality of spiral guide arms (127) are provided on the bottom wall outside the inner barrel (12), and the plurality of spiral guide arms (127) are arranged at intervals along the circumference of the inner barrel (12) and are used to guide the lithium carbonate material entering the intermediate chamber (6) from the material storage chamber (135) to converge at the discharge port (60) at the bottom of the kettle body (10).

5. The purification device for crude lithium carbonate according to claim 1, characterized in that: The bottom of the inner barrel (12) is provided with a liquid discharge port (125); the bottom of the liquid discharge port (125) is provided with an outer barrel (1250) and an inner barrel (1251); the outer barrel (1250) and the inner barrel (1251) are both fixed to the bottom wall outside the inner barrel (12); the inner barrel (1251) is located inside the outer barrel (1250); the bottoms of the inner barrel (1251) and the outer barrel (1250) are both open structures; the inner barrel (1251) A liquid discharge passage (1252) is formed between the inner cylinder (1251) and the outer cylinder (1250); a filter hole (126) communicating with the liquid discharge passage (1252) and the inner cylinder (1251) is provided on the inner cylinder (1251); a lifting cylinder (8) is provided inside the inner cylinder (1251); a sealing head (80) is drivingly connected to the telescopic end of the lifting cylinder (8); the sealing head (80) is used to seal the communication position between the liquid discharge port (125) and the filter hole (126).

6. The purification device for crude lithium carbonate according to claim 1, characterized in that: A driving gear (301) is fixed on the top of the stirring assembly (3); a driven gear (302) meshing with the driving gear (301) is rotatably provided on the kettle body (10); a first inner gear ring (1320) meshing with the driven gear (302) is fixed on the inner wall of the top end of the scraper barrel (13); an outer gear ring (1321) is fixed on the outer wall of the top end of the scraper barrel (13); a second inner gear ring (5) is fixed on the inner wall of the top end of the inner barrel (12); and an intermediate gear (4) meshing with the first inner gear ring (1320) and the second inner gear ring (5) is also provided on the kettle body (10).

7. A method for purifying crude lithium carbonate, characterized in that: Purifying crude lithium carbonate using a purification device as described in any one of claims 1 to 6, the method comprising the following steps: S1. Add sodium carbonate powder and lithium oxide solution or lithium sulfate solution into the inner barrel (12); S2, starting the driving unit (2), driving the stirring assembly (3) to stir the solution in the inner barrel (12), and at the same time driving the inner barrel (12) and the scraper barrel (13) to rotate relative to each other, so that the lithium carbonate generated by the reaction in the inner barrel (12) is gathered toward the inner wall of the inner barrel (12) under the action of the centrifugal force of the solution, and the lithium carbonate gathered on the inner wall of the inner barrel (12) is scraped into the storage chamber (135) for storage under the action of the scraper of the scraper barrel (13), and the liquid entering the storage chamber (135) along with the lithium carbonate flows back into the inner barrel (12) through the reflux pipe (122); S3. When the storage chamber (135) is filled with lithium carbonate, the scraper will squeeze the lithium carbonate material in the storage chamber (135) to force the gate (7) to open, so that the lithium carbonate material in the storage chamber (135) enters the middle chamber (6); S4, an air inlet (103) and an air outlet (104) are provided on the kettle body (10), and a hot air flow is introduced into the middle chamber (6) through the air inlet (103). The hot air flow heats and dries the lithium carbonate material in the middle chamber (6) and then is discharged through the air outlet (104); S5. The lithium carbonate material in the middle cavity (6) is heated and dried to form a crude lithium carbonate product. The crude lithium carbonate product falls into the bottom of the kettle body (10) and is discharged from the discharge port (60), thereby achieving purification of the crude lithium carbonate product.

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