A continuous production apparatus for producing lithium bicarbonate using CO2

Abstract

This invention provides a continuous production apparatus for preparing lithium bicarbonate using CO2, relating to the field of lithium carbonate preparation technology. It includes a feeding system, a mixing reaction unit, a clarification and separation unit, a frame, and a control system. The feeding system's organic phase feeding unit, aqueous phase feeding unit, and gas inlet unit enable precise proportioning and conveying of multiple materials. The preparation container of the mixing reaction unit is divided into multiple stirring chambers by annular baffles, each corresponding to a set of impellers. Optimized impeller parameters and axial spacing design, coupled with a microporous aeration device at the bottom of the preparation container, form a highly efficient composite flow field, enhancing three-phase mixing efficiency. The clarification and separation tank improves the gradient separation of the gas, liquid, and liquid phases through filter baffles. Through the coordinated operation of these systems, mixing reaction and product separation can be efficiently completed, achieving continuous production of lithium bicarbonate solution, ensuring product uniformity, and significantly improving CO2 utilization and gas-liquid mass transfer efficiency, which is of great significance for the industry's green and low-carbon transformation.

Description

Technical Field

[0001] This invention relates to the field of lithium carbonate preparation technology, and more particularly to a continuous production apparatus for preparing lithium bicarbonate using CO2. Background Technology

[0002] In the field of lithium resource development and utilization, with the rapid development of the new energy industry, the market demand for lithium products such as lithium carbonate and lithium hydroxide continues to rise. As a key intermediate product, lithium bicarbonate's efficient extraction technology is receiving increasing attention from the industry. Currently, lithium bicarbonate extraction technology mostly adopts a batch reaction mode, which occupies a mainstream position in the lithium salt production process.

[0003] Traditional batch processing typically involves adding CO2 gas, a lithium-rich organic phase, and pure water to a reaction vessel in a specific ratio. Under pressure, a stirrer is activated to mix the components for approximately 30 minutes to ensure sufficient contact between the CO2 and the organic phase, maximizing CO2 utilization. After the reaction is complete, the system is allowed to stand for at least 30 minutes to allow for three-phase separation of the CO2, organic phase, and lithium bicarbonate solution. The lithium bicarbonate, organic phase, and CO2 are then collected manually or using simple equipment, completing one batch of production.

[0004] This traditional batch reaction model has several drawbacks: First, the reaction process is discontinuous. Each batch of extraction requires a series of steps, including feeding, stirring, settling, and unloading, resulting in significant waiting intervals between batches and hindering continuous material processing, leading to low overall production efficiency. Second, product quality is unstable, primarily due to over-reliance on manual intervention. On one hand, manual operation is physically demanding, prone to errors due to fatigue, posing safety hazards. On the other hand, the randomness of human judgment and operation makes standardized control difficult, resulting in significant fluctuations in product quality and poor batch-to-batch consistency. In large-scale industrial production scenarios, this discontinuous production model struggles to meet growing market demands, severely restricting the improvement of enterprise capacity and the enhancement of product competitiveness.

[0005] To address the aforementioned issues of batch reaction methods, some companies have attempted to optimize stirring devices and adjust settling times, but true continuous production has not yet been achieved. Existing continuous production equipment still suffers from shortcomings such as low mass transfer efficiency and insufficient automation, making it difficult to adapt to complex and ever-changing production scenarios. With the market's increasing demands for lithium carbonate quality and capacity, coupled with increasingly stringent national environmental policies, traditional batch processes are no longer adequate for industry development. Developing a continuous production device for producing lithium bicarbonate from CO2 can achieve continuous production, ensure product quality uniformity, significantly improve CO2 utilization and gas-liquid mass transfer efficiency, and has significant practical implications and broad market prospects for promoting the industry's green and low-carbon transformation. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of the aforementioned technologies by providing a continuous production apparatus for preparing lithium bicarbonate using CO2. This solves the problems of low production efficiency, large fluctuations in product quality, and low CO2 utilization and gas-liquid-liquid mass transfer efficiency in traditional processes.

[0007] The technical solution of the present invention is as follows: a continuous production apparatus for preparing lithium bicarbonate using CO2 is provided, which includes five parts: a feeding system, a mixing reaction unit, a clarification and separation unit, a frame, and a control system.

[0008] The feeding system includes an organic phase feeding unit, an aqueous phase feeding unit, and an air intake unit. The organic phase feeding unit includes a metering pump and a flow meter. The metering pump is fixedly installed on the frame, and its outlet is connected to the inlet of the flow meter via a pipeline. The two are linked in a closed-loop control to achieve the delivery of the organic phase. The outlet of the flow meter is connected to the organic phase feed valve of the mixing reaction unit.

[0009] The water phase feed unit includes metering pump two and flow meter two. Metering pump two is fixedly installed on the frame adjacent to metering pump one. The outlet of metering pump two is connected to the inlet of flow meter two through a pipeline. The two are linked in a closed loop control to realize the delivery of pure water. The outlet of flow meter two is connected to the water supply valve of the mixing reaction unit.

[0010] The intake unit includes a CO2 storage tank, a pressure reducing valve, and a flow valve. The CO2 storage tank is located on one side of the frame. The outlet of the CO2 storage tank is connected to the inlet of the pressure reducing valve, and the outlet of the pressure reducing valve is connected to the inlet of the flow valve. The outlet of the flow valve is connected to the gas supply valve of the mixing reaction unit via a pipeline.

[0011] The mixing reaction unit includes a stirring device and a cylindrical preparation container. The stirring device includes a stirring motor, a stirring shaft, a sealing assembly, and impellers. The stirring motor is connected to the stirring shaft via a coupling. The stirring shaft has 5-20 sets of impellers, each set including 4-6 blades, which are evenly distributed and fixed to the stirring shaft. The sealing assembly is coaxially mounted with the stirring shaft to ensure the sealing performance of the preparation container. The stirring motor is fixed to the support of the preparation container via a bracket.

[0012] The preparation container is designed to withstand a pressure rating of not less than 0.3 MPa, and the preparation container is fixed to the frame by a bracket.

[0013] The upper part of the preparation container is provided with a discharge port 1. The discharge port 1 is connected in series with a pressure gauge and a back pressure valve through a pipeline, and is connected to the feed port 3 of the clarification and separation unit.

[0014] The lower part of the preparation container is provided with inlet 1 and inlet 2. Inlet 1 is connected to the organic phase feed valve and the water supply valve respectively through a three-way valve; inlet 2 is connected to the gas supply valve.

[0015] The preparation container is equipped with multiple annular baffles, which divide the container into multiple mixing chambers, each corresponding to a set of impellers. Several guide holes are evenly distributed on the annular baffles. This structure breaks the inherent trajectory of a single mixing flow field, promoting multidirectional turbulence in the mixture and enhancing the mixing effect.

[0016] The preparation container has 2-8 microporous aeration devices mounted on an aeration frame at the bottom. Each device is connected in series with the feed inlet via a pipe. The micron-sized fine bubbles generated by the microporous aeration devices can, to a certain extent, increase the gas-liquid contact area, improve the mixing rate, and enhance the mass transfer efficiency of CO2 with the organic phase and pure water.

[0017] An online pH monitor is installed on the side wall of the preparation container. The monitoring probe is directly immersed in the mixture, which can collect the pH data of the mixture in real time and feed it back to the control system. The control system dynamically controls the CO2 feed rate by automatically adjusting the flow valve. While ensuring a relatively stable pH in the reaction environment, it also effectively avoids the problem of resource waste caused by gas oversaturation.

[0018] The clarification and separation unit includes a clarification and separation tank. The clarification and separation tank has a horizontal structure and is fixed to the frame. The clarification and separation tank has three inlets, two gas outlets, one liquid outlet, and two liquid outlets. Inlet three is located at the feed end of the clarification and separation tank; gas outlet two is located at the top of the clarification and separation tank; liquid outlet one and liquid outlet two are both located at the discharge end of the clarification and separation tank. Liquid outlet one is used for the output of the organic phase solution; liquid outlet two is used for the output of the lithium bicarbonate solution. The clarification and separation tank is equipped with a dedicated filter baffle. The filter baffle has multiple evenly distributed holes, which can form a gradient separation and interception of the gas-liquid-liquid mixture composed of CO2, organic phase, and pure water. This structural design can significantly improve the separation efficiency of the mixture and significantly optimize the cleanliness of the separated product, ensuring more thorough and accurate separation.

[0019] The control system includes an electrical control cabinet, which is installed at the bottom of the frame.

[0020] Preferably, the ratio of the axial spacing between each group of impellers to the impeller stirring diameter size factor is 0.8-1.2.

[0021] Preferably, the ratio of the impeller stirring diameter to the container inner diameter is 0.4-0.8.

[0022] Compared with existing technologies, the beneficial effects of this invention are: 1. This invention achieves continuous mixing and reaction of organic phase, pure water, and CO2 through the synergistic action of the feeding system, mixing reaction unit, clarification and separation unit, and control system, ultimately obtaining a high-purity lithium bicarbonate solution through clarification and separation. Through fully automated continuous control, continuous feeding of raw materials and continuous discharge of products are achieved, effectively eliminating time losses caused by non-production stages such as feeding, settling, and unloading in traditional intermittent operations, significantly improving overall production efficiency and equipment utilization, and greatly increasing the production capacity per unit time. 2. The working mode of this invention, which features precise continuous feeding, efficient mixing, dynamic control, gradient separation, and continuous and stable product output, reduces reliance on manual operation, avoids batch-to-batch differences, and enables the prepared lithium bicarbonate products to exhibit excellent batch consistency and stable reliability, thus ensuring the uniformity of product quality. 3. This invention, through the structural design of setting an annular partition in the preparation container, combined with the micron-sized bubbles generated by the microporous aeration device, enables the mixed liquid to form multi-directional turbulence, which not only increases the gas-liquid contact area and improves the mass transfer efficiency, but also enhances the mixing efficiency; at the same time, it effectively avoids the problem of instantaneous crystallization and inner wall adhesion of lithium bicarbonate caused by excessively high local CO2 concentration, and realizes the efficient, stable and green operation of the lithium bicarbonate preparation process. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 : A schematic diagram of a continuous production apparatus for preparing lithium bicarbonate using CO2 according to the present invention.

[0025] Figure 2 : Schematic diagram of the mixed reaction unit structure of the present invention.

[0026] Figure 3 : 1-1 sectional view of the present invention.

[0027] Figure 4 : Schematic diagram of the filter partition structure of the present invention.

[0028] In the diagram: 1.11-Metering pump one, 1.12-Flow meter one, 1.21-Metering pump two, 1.22-Flow meter two, 1.31-CO2 storage tank, 1.32-Outlet one, 1.33-Pressure reducing valve, 1.34-Flow valve, 2.1-Agitator, 2.11-Agitator motor, 2.12-Agitator shaft, 2.13-Sealing assembly, 2.14-Impeller, 2.15-Coupling, 2.17-Blade, 2.18-Support, 2.2-Preparation container, 2.21-Annular baffle, 2.22-Agitator chamber, 2.23-Flow guide hole, 2.24-pH setting 2.25-Line monitoring instrument, 2.25-Microporous aeration device, 2.251-Aeration base frame, 2.26-Inlet 1, 2.261-Organic phase feed valve, 2.262-Water supply valve, 2.27-Inlet 2, 2.271-Air supply valve, 2.28-Three-way valve, 2.29-Outlet 1, 2.291-Pressure gauge, 2.292-Back pressure valve, 2.3-Support, 3.1-Clarification and separation tank, 3.11-Inlet 3, 3.12-Air outlet 2, 3.13-Liquid outlet 1, 3.14-Liquid outlet 2, 3.15-Filter plate, 4-Frame, 5.1-Electrical control cabinet. Detailed Implementation

[0029] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions in the embodiments of this invention are clearly and completely described below. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0030] Figures 1-4 As shown, the present invention provides a continuous production apparatus for preparing lithium bicarbonate using CO2, which includes five parts: a feeding system, a mixing reaction unit 2, a clarification and separation unit 3, a frame 4, and a control system.

[0031] The feeding system includes an organic phase feeding unit, an aqueous phase feeding unit, and an air intake unit. The organic phase feeding unit includes a metering pump 1.11 and a flow meter 1.12. The metering pump 1.11 is fixedly installed on the frame 4, and the outlet of the metering pump 1.11 is connected to the inlet of the flow meter 1.12 through a pipeline. The two are linked in a closed loop to realize the organic phase conveying. The outlet of the flow meter 1.12 is connected to the organic phase feed valve 2.261 of the mixing reaction unit 2.

[0032] The water phase feed unit includes metering pump 1.21 and flow meter 1.22. Metering pump 1.21 and metering pump 1.11 are fixedly installed on the frame 4 adjacent to each other. The outlet of metering pump 1.21 is connected to the inlet of flow meter 1.22 through a pipe. The two are linked in a closed loop to realize pure water delivery. The outlet of flow meter 1.22 is connected to the water supply valve 2.262 of the mixing reaction unit 2.

[0033] The air intake unit includes a CO2 storage tank 1.31, a pressure reducing valve 1.33, and a flow valve 1.34. The CO2 storage tank 1.31 is located on one side of the frame 4. The outlet 1.32 of the CO2 storage tank 1.31 is connected to the inlet of the pressure reducing valve 1.33, and the outlet of the pressure reducing valve 1.33 is connected to the inlet of the flow valve 1.34. The outlet of the flow valve 1.34 is connected to the air supply valve 2.271 of the mixing reaction unit 2 via a pipeline.

[0034] The mixing reaction unit includes a stirring device 2.1 and a cylindrical preparation container 2.2. The stirring device 2.1 includes a stirring motor 2.11, a stirring shaft 2.12, a sealing assembly 2.13, and impellers 2.14. The stirring motor 2.11 is connected to the stirring shaft 2.12 via a coupling 2.15. The stirring shaft 2.12 is equipped with 5-20 sets of impellers 2.14, each set of impellers 2.14 including 4-6 blades 2.17, which are evenly distributed and fixed on the stirring shaft 2.12. The sealing assembly 2.13 is coaxially arranged with the stirring shaft 2.12. The stirring motor 2.11 is fixed to the support 2.3 of the preparation container via a support 2.18.

[0035] The preparation container 2.2 is designed to withstand a pressure rating of not less than 0.3 MPa, and the preparation container 2.2 is fixed to the frame 4 by a bracket 2.3.

[0036] The upper part of the preparation container 2.2 is provided with a discharge port 2.29. The discharge port 2.29 is connected in series with a pressure gauge 2.291 and a back pressure valve 2.292 through a pipeline, and is connected to the feed port 3.11 of the clarification and separation unit 3.

[0037] The lower part of the preparation container 2.2 is provided with a first feed port 2.26 and a second feed port 2.27. The first feed port 2.26 is connected to the organic phase feed valve 2.261 and the water supply valve 2.262 respectively through a three-way valve 2.28. The second feed port 2.27 is connected to the air supply valve 2.271.

[0038] The preparation container 2.2 is internally equipped with multiple annular baffles 2.21, which divide it into multiple stirring chambers 2.22, each stirring chamber 2.22 corresponding to a set of impellers. Several guide holes 2.23 are evenly distributed on the annular baffles 2.21.

[0039] The bottom of the preparation container 2.2 is equipped with 2-8 microporous aeration devices 2.25 via an aeration base 2.251. Each device is connected in series with the feed inlet 2.27 via a pipe. A pH online monitor 2.24 is installed on the side wall of the preparation container 2.2, with the monitoring probe directly immersed in the mixture.

[0040] The clarification and separation unit 3 includes a clarification and separation tank 3.1. The clarification and separation tank 3.1 has a horizontal structure and is fixed on the frame 4. The clarification and separation tank 3.1 is provided with a third inlet 3.11, a second gas outlet 3.12, a first liquid outlet 3.13, and a second liquid outlet 3.14. The third inlet 3.11 is located at the feed end of the clarification and separation tank 3.1; the second gas outlet 3.12 is located at the top of the clarification and separation tank 3.1; the first liquid outlet 3.13 and the second liquid outlet 3.14 are both located at the discharge end of the clarification and separation tank 3.1. The clarification and separation tank 3.1 is equipped with a dedicated filter baffle 3.15, which has multiple holes evenly distributed on it, and can form a gradient separation and interception of the gas-liquid-liquid mixture composed of CO2, organic phase, and pure water.

[0041] The control system includes an electrical control cabinet 5.1, which is installed at the bottom of the frame.

[0042] The ratio of the axial spacing between each impeller group 2.14 to the impeller stirring diameter size factor is 0.8-1.2.

[0043] The ratio of the impeller 2.14 stirring diameter to the container inner diameter is 0.4-0.8.

[0044] Working principle: This device uses the chemical reaction formula: Li + The basic principle is (organic phase) + CO2 + H2O → LiHCO3 (aqueous phase). It adopts a working mode of "continuous feeding - efficient mixing - dynamic control - gradient separation - continuous and stable product output". Through the coordinated operation of the feeding system, mixing reaction unit, clarification separation unit, and control system, it achieves continuous mixing and reaction of organic phase, pure water, and CO2, ultimately clarifying and separating to obtain a high-purity lithium bicarbonate solution. During operation, CO2, the organic phase, and pure water are precisely metered into the mixing reaction unit via the feeding system in specific proportions. The molar flow ratio of the three phases is 6:20:1 - 120:200:1; the lithium concentration in the organic phase is 1.5g-2g / L. The control system automatically adjusts the flow valve dynamically to control the CO2 feed rate based on real-time feedback from online pH monitoring. Micron-sized bubbles are uniformly released through a bottom-mounted microporous aeration device, and the combined flow field and turbulence effect created by the stirring device significantly enhance the mixing efficiency of the gas-liquid-liquid three-phase mixture, thereby effectively improving CO2 utilization and mass transfer efficiency. The gas-liquid-liquid mixture generated by the rapid and efficient reaction is pressurized by a back pressure valve and then enters a clarification and separation tank. After gradient separation and interception by a filter baffle, CO2 gas, the organic phase, and the lithium bicarbonate solution are efficiently separated and discharged, ultimately completing the continuous preparation process of lithium bicarbonate. After clarification and separation, the Li in the organic phase... + The content can be reduced to below 0.1g / L.

[0045] Although this description has been given in detail with reference to the accompanying drawings and preferred embodiments, the invention is not limited thereto. Any variations and substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this invention without departing from the spirit and essence of the invention should be included within the protection scope of this invention. Therefore, the protection scope of this invention should be determined by the scope of the claims.

Claims

1. A continuous production apparatus for preparing lithium bicarbonate using CO2, comprising five parts: a feeding system, a mixing reaction unit 2, a clarification and separation unit 3, a frame 4, and a control system, characterized in that: The mixing reaction unit includes a stirring device 2.1 and a cylindrical preparation container 2.2; the stirring device 2.1 includes a stirring motor 2.11, a stirring shaft 2.12, and impellers 2.14; the stirring motor 2.11 is connected to the stirring shaft 2.12 via a coupling 2.15, and the stirring shaft 2.12 is provided with 5-20 sets of impellers 2.14, each set of impellers 2.14 including 4-6 blades 2.17, which are evenly distributed and fixed on the stirring shaft 2.12; the stirring motor 2.11 is fixed to the support 2.3 of the preparation container via a support 2.18; The preparation container 2.2 is designed to withstand a pressure rating of not less than 0.3 MPa, and the preparation container 2.2 is fixed to the frame 4 by a bracket 2.3; The upper part of the preparation container 2.2 is provided with a discharge port 2.

29. The discharge port 2.29 is connected in series with a pressure gauge 2.291 and a back pressure valve 2.292 through a pipeline, and is connected to the feed port 3.11 of the clarification and separation unit 3. The lower part of the preparation container 2.2 is provided with a first feed port 2.26 and a second feed port 2.

27. The first feed port 2.26 is connected to the organic phase feed valve 2.261 and the water supply valve 2.262 respectively through a three-way valve 2.

28. The second feed port 2.27 is connected to the air supply valve 2.

271. The preparation container 2.2 is provided with multiple annular baffles 2.21 inside, which divide it into multiple stirring chambers 2.

22. Each stirring chamber 2.22 corresponds to a set of impellers; a number of flow guide holes 2.23 are evenly opened on the annular baffles 2.

21. The bottom of the preparation container 2.2 is equipped with 2-8 microporous aeration devices via an aeration base 2.

251. 2.25, each device is connected in series through a pipe and connected to the feed inlet 2.27; a pH online monitor 2.24 is installed on the side wall of the preparation container 2.2, and the monitoring probe is directly immersed in the mixture.

2. The continuous production apparatus for preparing lithium bicarbonate using CO2 according to claim 1, characterized in that: The clarification and separation unit 3 includes a clarification and separation tank 3.1, which has a horizontal structure and is fixed on the frame 4. The clarification and separation tank 3.1 is provided with a third inlet 3.11, a second outlet 3.12, a first outlet 3.13, and a second outlet 3.

14. The third inlet 3.11 is located at the inlet end of the clarification and separation tank 3.

1. The second outlet 3.12 is located at the top of the clarification and separation tank 3.

1. The first outlet 3.13 and the second outlet 3.14 are both located at the outlet end of the clarification and separation tank 3.

1. The clarification and separation tank 3.1 is provided with a dedicated filter baffle 3.15, which has multiple holes evenly distributed on it, and can form a gradient separation and interception of the gas-liquid-liquid mixture composed of CO2, organic phase, and pure water.

3. The continuous production apparatus for preparing lithium bicarbonate using CO2 according to claim 1, characterized in that: The ratio of the axial spacing between each impeller group 2.14 to the impeller stirring diameter size factor is 0.8-1.

2.

4. A continuous production apparatus for preparing lithium bicarbonate using CO2 according to claim 1, characterized in that: The ratio of the impeller 2.14 stirring diameter to the container inner diameter is 0.4-0.8.

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