Continuous production system for lithium carbonate production

Abstract

The invention discloses a continuous production system for lithium carbonate production, which is characterized in that a plurality of carbonization kettles are connected in series in an overflow manner, raw material liquid flows into a first-stage carbonization kettle, the side wall of the first-stage carbonization kettle overflows to the top of a second-stage carbonization kettle for feeding, and the like, and the side wall of the last-stage carbonization kettle overflows for discharging. And carbon dioxide is quantitatively introduced into each carbonization kettle through multiple pipe orifices, so that liquid in each carbonization kettle can fully react. The continuous discharging device can continuously discharge materials, has no material loss, and is unattended.

Description

Technical Field

[0001] The invention relates to the technical field of chemical industry, in particular to a continuous production system for lithium carbonate production. Background Art

[0002] Lithium carbonate is widely used to prepare various lithium compounds, metallic lithium and its isotopes. In recent years, it has been widely used in lithium-ion batteries. It can be used as a raw material for preparing battery positive electrodes, and can also be directly used as a positive electrode material to prepare lithium carbonate batteries.

[0003] At present, lithium carbonate is generally prepared by continuous carbonization using a multi-stage carbonization tower or single-pot carbonization. When a multi-stage carbonization tower is used for continuous carbonization, the material liquid is pumped to the spray port at the top of the carbonization tower for spraying, and carbon dioxide is introduced into the carbonization tower from the bottom of the tower. The carbon dioxide gas and the material liquid flow in reverse and react, and each stage of the carbonization tower needs to be pumped to the top of the tower for spraying. Although this method has a relatively full reaction and can also achieve continuous discharge, the material will stick to the wall of the equipment barrel and the spray port, resulting in blockage of the spray port. The spray port and the inner wall of the barrel need to be cleaned frequently, and the material loss is large, the inspection and maintenance are relatively complicated, and production cannot be continued during cleaning; and when a single-pot carbonization is used, after each kettle is carbonized, the material is discharged to a centrifuge for subsequent treatment, and then carbon dioxide and lithium hydroxide materials are quantitatively introduced into the carbonization kettle for carbonization. This method requires real-time detection of the reaction and discharge conditions of each kettle during the production process, and personnel need to be on duty for a long time on site, with high labor intensity, low production efficiency, a large number of equipment, a large footprint, and cannot achieve continuous discharge. Summary of the invention

[0004] The present application provides a continuous production system for lithium carbonate production, which can discharge materials continuously without material loss and without the need for personnel on duty.

[0005] The continuous production system for lithium carbonate production provided in the present application comprises a plurality of carbonization kettles, a feeding pipeline, a gas feeding pipeline, an exhaust pipeline and a delivery pump;

[0006] A feed port and an exhaust port are arranged on the top of each carbonization kettle, an air inlet pipe is arranged inside each carbonization kettle, and a discharge port is arranged on the side wall of each carbonization kettle. Multiple carbonization kettles are arranged in sequence and the placement heights are successively reduced;

[0007] The feed inlet of the carbonization kettle placed at the highest height is connected to a feeding pipeline, and the feeding pipeline is used to feed the lithium hydroxide solution into the carbonization kettle;

[0008] The discharge port of any carbonization kettle is connected to the feed port of the adjacent carbonization kettle placed at a lower height than itself, and the discharge port of any carbonization kettle is higher than the feed port of the adjacent carbonization kettle placed at a lower height than itself;

[0009] The air inlet pipe in each carbonization kettle is connected to the air supply pipe, and the air inlet pipe is used to input the carbon dioxide gas in the air supply pipe into the carbonization kettle so that the carbon dioxide gas contacts the lithium hydroxide solution in the carbonization kettle, and the exhaust port of each carbonization kettle is connected to the exhaust pipe;

[0010] The discharge port of the carbonization kettle placed at the lowest height is close to the bottom of the carbonization kettle, and the discharge port of the carbonization kettle placed at the lowest height is connected to the inlet of the delivery pump, and the outlet of the delivery pump is used to transport lithium carbonate slurry to the outside.

[0011] Preferably, each carbonization kettle is provided with a plurality of air inlet pipes, the upper end of each air inlet pipe is connected to the air supply pipe, the lower end of each air inlet pipe is located near the bottom of the carbonization kettle, the lower end of each air inlet pipe is closed, and the tube wall of each air inlet pipe is covered with air outlet holes.

[0012] Preferably, a heat exchange tube is spirally wound on the outer wall of each of the carbonization kettles except the carbonization kettle with the lowest placement height, one end of each heat exchange tube is connected to the steam main pipe, and the other end of each heat exchange tube is connected to the condensate recovery pipe. The steam main pipe is used to transport water vapor to each heat exchange tube, the heat exchange tube is used to heat the carbonization kettle, and the condensate recovery pipe is used to recover the condensed water in the heat exchange tube.

[0013] Preferably, the bottom of the carbonization kettle placed at the lowest height is inclined to form a low-lying side, and the discharge port of the carbonization kettle is close to the low-lying side.

[0014] Preferably, a stirring shaft and stirring blades fixedly arranged on the stirring shaft are arranged in each carbonization kettle, and a motor for driving the stirring shaft to rotate is arranged on the top of each carbonization kettle.

[0015] Preferably, a bracket is provided in the area near the discharge port of the inner wall of the carbonizing kettle, and a rotating member is provided on the bracket, the rotating member includes a first rotating rod, a second rotating rod and a third rotating rod, the first rotating rod is rotatably installed on the bracket, the first rotating rod is coaxially arranged with the discharge port, the third rotating rod extends into a pipeline coaxially connected with the discharge port, the third rotating rod is parallel to the axis of the pipeline, and the third rotating rod is attached to the inner wall of the pipeline, the second rotating rod connects the first rotating rod with the third rotating rod, and the first rotating rod is fixedly connected to a gear; an end face gear is fixedly provided on the stirring shaft, the stirring shaft can drive the end face gear to rotate, the end face of the end face gear has an annular gear ring, the gear is meshed with the annular gear ring, and when the end face gear rotates, the rotating member can be driven to rotate through the gear, so that the third rotating rod rotates around the axis of the pipeline.

[0016] One or more technical solutions provided in this application have at least the following technical effects or advantages:

[0017] The continuous production system of the present application adopts multiple carbonization kettles overflowed in series, the raw material liquid flows into the first-stage carbonization kettle, the side wall of the first-stage carbonization kettle overflows to the top of the second-stage carbonization kettle for feeding, and so on, the side wall of the last-stage carbonization kettle overflows for discharging, and each carbonization kettle is quantitatively introduced with carbon dioxide through multiple pipes to ensure that the liquid in each carbonization kettle can fully react. The present application can meet the requirements of stable feeding, stable operation, and continuous discharging, and the system structure is simple, the inspection and maintenance are convenient, and there is no material loss, which can achieve unmanned automatic control and long-term stable operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0019] Figure 1 It is a schematic diagram of the pipeline structure of the present invention.

[0020] Figure 2 It is a structural schematic diagram of the carbonization kettle.

[0021] The accompanying drawings are marked as follows: 10, carbonization kettle; 11, feed port; 12, air inlet pipe; 13, exhaust port; 14, discharge port; 141, pipeline; 15, bracket; 16, gear; 17, rotating part; 171, first rotating rod; 172, second rotating rod; 173 third rotating rod; 18, end gear; 181, annular gear ring; 101, heat exchange tube; 102, low-lying side; 103, stirring shaft; 104, stirring blade; 105, motor; 20, feed pipe; 21, ball valve; 30, air pipe; 40, exhaust pipe; 50, delivery pump; 60, steam main pipe; 61, first solenoid valve; 70, condensate recovery pipe; 71, second solenoid valve. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0023] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product, or server that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or modules that are not clearly listed or inherent to these processes, methods, products, or devices.

[0024] like Figure 1 , Figure 2 As shown, the continuous production system for lithium carbonate production of this embodiment includes four carbonization kettles 10, a feeding pipeline 20, a gas feeding pipeline 30, an exhaust pipeline 40 and a delivery pump 50.

[0025] A feed port 11 and an exhaust port 13 are provided on the top of each carbonization kettle 10 , an air inlet pipe 12 is provided inside each carbonization kettle 10 , and a discharge port 14 is provided on the side wall of each carbonization kettle 10 . The four carbonization kettles 10 are arranged in sequence and the placement heights are successively reduced.

[0026] The feed port 11 of the carbonization kettle 10 placed at the highest height is connected to the feeding pipe 20, which is used to feed the lithium hydroxide solution into the carbonization kettle 10, and a ball valve 21 is provided on the pipeline between the feed port 11 of the carbonization kettle 10 placed at the highest height and the feeding pipe 20.

[0027] The discharge port 14 of any carbonization kettle 10 is connected to the feed port 11 of the adjacent carbonization kettle 10 placed at a lower height than itself, and the discharge port 14 of any carbonization kettle 10 is higher than the feed port 11 of the adjacent carbonization kettle 10 placed at a lower height than itself, so that the liquid in any carbonization kettle 10 can overflow through the discharge port 14 into the adjacent carbonization kettle 10 placed at a lower height than itself.

[0028] The air inlet pipe 12 in each carbonizing kettle 10 is connected to the air supply pipe 30. The air inlet pipe 12 is used to input the carbon dioxide gas in the air supply pipe 30 into the carbonizing kettle 10 so that the carbon dioxide gas contacts the lithium hydroxide solution in the carbonizing kettle 10. The exhaust port 13 of each carbonizing kettle 10 is connected to the exhaust pipe 40. In this way, the carbon dioxide gas is fed into the carbonizing kettle 10 through the air inlet pipe 12 and reacts with the lithium hydroxide solution in the carbonizing kettle 10. The excess carbon dioxide gas is discharged through the exhaust port 13.

[0029] The discharge port 14 of the carbonizing kettle 10 placed at the lowest height is close to the bottom of the carbonizing kettle 10, and the discharge port 14 of the carbonizing kettle 10 placed at the lowest height is connected to the inlet of the delivery pump 50, and the outlet of the delivery pump 50 is used to deliver the lithium carbonate slurry to the outside. In this way, the lithium carbonate slurry obtained by the reaction in the carbonizing kettle 10 placed at the lowest height is delivered to the outside through the delivery pump 50, and the lithium carbonate slurry is heat treated, filtered and dried to obtain a solid lithium carbonate product.

[0030] Each carbonization kettle 10 is provided with a plurality of air inlet pipes 12, the upper end of each air inlet pipe 12 is connected to the air supply pipe 30, the lower end of each air inlet pipe 12 is located near the bottom of the carbonization kettle 10, the lower end of each air inlet pipe 12 is closed, and the wall of each air inlet pipe 12 is covered with air outlet holes, so that when the carbon dioxide gas enters the carbonization kettle 10 through the air inlet pipe 12, the carbon dioxide gas can be in contact with the solution in the carbonization kettle 10 more evenly, so that the reaction between the carbon dioxide and the lithium hydroxide solution is more sufficient.

[0031] A heat exchange tube 101 is spirally wound on the outer wall of each of the carbonization kettles 10 except the carbonization kettle 10 placed at the lowest height. One end of each heat exchange tube 101 is connected to the steam main pipe 60 through the first solenoid valve 61, and the other end of each heat exchange tube 101 is connected to the condensate recovery pipe 70 through the second solenoid valve 71. The steam main pipe 60 is used to transport water vapor to each heat exchange tube 101, and the heat exchange tube 101 is used to heat the carbonization kettle 10. The condensate recovery pipe 70 is used to recover the condensate in the heat exchange tube 101. In this way, water vapor can bring heat to the heat exchange tube 101, so as to heat the carbonization kettle 10 through the heat exchange tube 101, so as to increase the temperature of the lithium hydroxide solution in the carbonization kettle 10, thereby making the reaction effect of carbon dioxide in the carbonization kettle 10 and the lithium hydroxide solution better.

[0032] The bottom of the carbonization kettle 10 placed at the lowest height is tilted to form a low-lying side 102, and the discharge port 14 of the carbonization kettle 10 is close to the low-lying side 102. In this way, due to the tilt of the bottom of the carbonization kettle 10, the lithium carbonate slurry in the carbonization kettle 10 can accumulate in the low-lying side 102, so that the lithium carbonate slurry can be discharged from the discharge port 14 more smoothly.

[0033] Each carbonization kettle 10 is provided with a stirring shaft 103 and a stirring blade 104 fixed on the stirring shaft 103. The top of each carbonization kettle 10 is provided with a motor 105 for driving the stirring shaft 103 to rotate. In this way, the motor 105 drives the stirring shaft 103 to rotate, thereby driving the stirring blade 104 to rotate. The stirring blade 104 can stir the carbon dioxide gas and the lithium hydroxide solution in the carbonization kettle 10 evenly, which is more conducive to the reaction between the two.

[0034] A bracket 15 is provided in the area near the discharge port 14 of the inner wall of the carbonizing kettle 10, and the bracket 15 is directly opposite to the discharge port 14. A rotating member 17 is provided on the bracket 15, and the rotating member 17 is Z-shaped. The rotating member 17 includes a first rotating rod 171, a second rotating rod 172 and a third rotating rod 173. The first rotating rod 171 is rotatably installed on the bracket 15, and the first rotating rod 171 is coaxially arranged with the discharge port 14, and the third rotating rod 173 extends into the pipeline 141 coaxially connected with the discharge port 14, and the third rotating rod 173 is parallel to the axis of the pipeline 141, and the third rotating rod 173 is attached to the inner wall of the pipeline 141, and the second rotating rod 172 connects the first rotating rod 171 with the third rotating rod 173, and the second rotating rod 172 is fixedly connected to the first rotating rod 171 and the third rotating rod 173 respectively. The gear 16 is fixedly connected, and the first rotating rod 171 is coaxially arranged with the gear 16; an end face gear 18 is fixedly arranged on the stirring shaft 103, and the end face gear 18 is coaxially arranged with the stirring shaft 103. The stirring shaft 103 can drive the end face gear 18 to rotate, and an annular ring gear 181 is provided on the end face of the end face gear 18. The gear 16 is meshed with the annular ring gear 181, and the axis of the gear 16 is perpendicular to the axis of the annular ring gear 181. When the end face gear 18 rotates, the rotating member 17 can be driven to rotate through the gear 16, so that the third rotating rod 173 rotates around the axis of the pipeline 14, so that when the stirring shaft 103 rotates, the third rotating rod 173 can continuously rotate in the discharge port 14 to scrape the inner walls of the discharge port 14 and the pipeline 141 to avoid clogging of the discharge port 14 and the inner wall of the pipeline 141 near the discharge port 14 due to material adhesion.

[0035] Moreover, there is a gap between the end gear 18 and the inner wall of the carbonizing kettle 10, and the air inlet pipe 12 can enter under the end gear 18 through the gap between the end gear 18 and the inner wall of the carbonizing kettle 10. Adjacent carbonizing kettles 10 are connected by pipelines 141 for overflow.

[0036] It should be noted that the above-mentioned sequence of the embodiments of the present application is only for description and does not represent the advantages and disadvantages of the embodiments. And the above-mentioned specific embodiments of this specification are described. Other embodiments are within the scope of the attached claims. In some cases, the actions or steps recorded in the claims can be performed in an order different from that in the embodiments and still achieve the desired results. In addition, the processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0037] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

[0038] This specification and drawings are merely exemplary illustrations of the present application and are deemed to cover any and all modifications, variations, combinations or equivalents within the scope of the present application. Obviously, a person skilled in the art may make various modifications and variations to the present application without departing from the scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the present application and its equivalents, the present application intends to include these modifications and variations.

Claims

1. A continuous production system for lithium carbonate production, characterized in that, It comprises a plurality of carbonization kettles (10), a material feeding pipeline (20), a gas feeding pipeline (30), an exhaust pipeline (40) and a delivery pump (50); A feed port (11) and an exhaust port (13) are provided on the top of each carbonization kettle (10), an air inlet pipe (12) is provided inside each carbonization kettle (10), and a discharge port (14) is provided on the side wall of each carbonization kettle (10), and a plurality of carbonization kettles (10) are arranged in sequence and the placement heights are successively reduced; The feed inlet (11) of the carbonization kettle (10) placed at the highest height is connected to a feeding pipe (20), and the feeding pipe (20) is used to feed the lithium hydroxide solution into the carbonization kettle (10); The discharge port (14) of any carbonization kettle (10) is connected to the feed port (11) of an adjacent carbonization kettle (10) placed at a lower height than the carbonization kettle (10), and the discharge port (14) of any carbonization kettle (10) is higher than the feed port (11) of an adjacent carbonization kettle (10) placed at a lower height than the carbonization kettle (10); The air inlet pipe (12) in each carbonization kettle (10) is connected to the air supply pipe (30), and the air inlet pipe (12) is used to input the carbon dioxide gas in the air supply pipe (30) into the carbonization kettle (10) so that the carbon dioxide gas contacts the lithium hydroxide solution in the carbonization kettle (10), and the exhaust port (13) of each carbonization kettle (10) is connected to the exhaust pipe (40); The discharge port (14) of the carbonization kettle (10) placed at the lowest height is close to the bottom of the carbonization kettle (10), and the discharge port (14) of the carbonization kettle (10) placed at the lowest height is connected to the inlet of the delivery pump (50), and the outlet of the delivery pump (50) is used to deliver lithium carbonate slurry to the outside.

2. The continuous production system according to claim 1, characterized in that: A plurality of air inlet pipes (12) are arranged in each carbonization kettle (10), the upper end of each air inlet pipe (12) is connected to the air supply pipe (30), the lower end of each air inlet pipe (12) is located near the bottom of the carbonization kettle (10), the lower end of each air inlet pipe (12) is closed, and the pipe wall of each air inlet pipe (12) is covered with air outlet holes.

3. The continuous production system according to claim 1, characterized in that: A heat exchange tube (101) is spirally wound on the outer wall of each of the remaining carbonization kettles (10) except the carbonization kettle (10) placed at the lowest height. One end of each heat exchange tube (101) is connected to the steam main pipe (60), and the other end of each heat exchange tube (101) is connected to the condensate recovery pipe (70). The steam main pipe (60) is used to transport water vapor to each heat exchange tube (101), the heat exchange tube (101) is used to heat the carbonization kettle (10), and the condensate recovery pipe (70) is used to recover the condensate in the heat exchange tube (101).

4. The continuous production system according to claim 1, characterized in that: The bottom of the carbonization kettle (10) placed at the lowest height is inclined to form a low-lying side (102), and the discharge port (14) of the carbonization kettle (10) is close to the low-lying side (102).

5. The continuous production system according to claim 1, characterized in that: Each carbonization kettle (10) is provided with a stirring shaft (103) and a stirring blade (104) fixedly arranged on the stirring shaft (103), and a motor (105) for driving the stirring shaft (103) to rotate is provided on the top of each carbonization kettle (10).

6. The continuous production system according to claim 5, characterized in that: A bracket (15) is provided in an area near the discharge port (14) on the inner wall of the carbonization kettle (10), and a rotating member (17) is provided on the bracket (15). The rotating member (17) includes a first rotating rod (171), a second rotating rod (172) and a third rotating rod (173). The first rotating rod (171) is rotatably mounted on the bracket (15). The first rotating rod (171) is coaxially arranged with the discharge port (14). The third rotating rod (173) extends into a pipeline (141) coaxially connected with the discharge port (14). The third rotating rod (173) is parallel to the axis of the pipeline (141), and the third rotating rod (173) fits closely to the pipeline. On the inner wall of the mixing shaft (141), a second rotating rod (172) connects the first rotating rod (171) and the third rotating rod (173), and the first rotating rod (171) is fixedly connected to a gear (16); an end face gear (18) is fixedly arranged on the mixing shaft (103), and the mixing shaft (103) can drive the end face gear (18) to rotate. An annular gear ring (181) is provided on the end face of the end face gear (18), and the gear (16) is meshed with the annular gear ring (181). When the end face gear (18) rotates, it can drive the rotating member (17) to rotate through the gear (16), so that the third rotating rod (173) rotates around the axis of the pipeline (14).

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