A lithium hydroxide carbonation continuous reactor

Abstract

This application relates to the fields of environmental protection chemical equipment and lithium salt production, and discloses a continuous lithium hydroxide carbonization reactor. The reactor includes a carbonization tower, a feed preheating unit, a circulating stirring unit, a tail gas recovery unit, a discharge anti-clogging unit, a discharge transfer unit, and a gas distribution unit. This invention improves gas-liquid contact efficiency by employing an anti-clogging gas distribution structure at the bottom of the tower; the tail gas is further absorbed by the feed buffer tank and dehumidified by the condenser before being discharged, improving carbon dioxide utilization; a corrosion-resistant filter screen is installed at the discharge port to prevent scale buildup, and an online switching and cleaning system is adopted using multiple towers in parallel with a two-on-one standby mode. This invention has advantages such as continuous carbonization, anti-clogging and scale prevention, high efficiency and energy saving, tail gas recovery, and stable operation. It effectively solves the problems of easy scaling and clogging, intermittent inefficiency, low carbon dioxide utilization, and poor product stability in traditional devices, and is suitable for the industrial production of lithium carbonate from continuous lithium hydroxide carbonization.

Description

Technical Field

[0001] This application relates to the fields of environmental protection chemical equipment and lithium salt production technology, and in particular to a continuous reactor for the carbonization of lithium hydroxide. Background Technology

[0002] In the current context of the rapid development of the new energy lithium battery industry, lithium salt production belongs to the field of environmental protection chemical supporting engineering. As the core raw material for the production of lithium battery cathode and electrolyte, the environmental protection, energy conservation and consumption reduction, clean construction and stable operation of its production process are important concerns for environmental protection engineering construction and chemical equipment application.

[0003] Currently, the production of lithium carbonate from lithium hydroxide generally adopts the carbonization reaction process. Traditional carbonization reaction equipment mostly uses batch reactors and simple tower structures, which have obvious environmental and process shortcomings: First, the gas-liquid contact effect is poor, the reaction conversion rate is low, the carbon dioxide emissions are large, and the resource waste is serious, which does not meet the clean emission reduction requirements of environmental protection projects; Second, the reaction process is prone to crystal adhesion and equipment scaling and blockage, resulting in unstable production conditions, frequent shutdowns for cleaning, increased operation and maintenance costs, and is not conducive to the standardized construction of environmental protection sites in chemical plants; Third, traditional equipment lacks a complete tail gas recovery and purification supporting structure, and unreacted waste gas is directly emitted, which wastes raw materials and causes air pollution, resulting in poor environmental compliance; Fourth, most of them are single-tower batch production, without parallel backup and online switching design, resulting in weak continuous production capacity, which is difficult to adapt to the large-scale, intensive, and low-emission production and construction standards of modern environmental protection projects.

[0004] Meanwhile, traditional carbonization equipment mostly adopts a mechanical stirring structure, which is prone to environmental hazards such as seal leakage and material spillage. It also lacks environmentally friendly and energy-saving designs such as closed-loop circulation, gas distribution, and waste heat utilization, making it impossible to balance production efficiency, product quality, and environmental compliance. Therefore, there is an urgent need to design a continuous lithium hydroxide carbonization reactor that is adapted to the requirements of environmental engineering construction, has tail gas recovery, anti-clogging and anti-scaling functions, waste heat utilization, and continuous and stable operation, so as to meet the engineering application needs of clean production, energy conservation and emission reduction, and environmental compliance in the lithium salt chemical industry. Summary of the Invention

[0005] This application proposes a continuous carbonization reactor for lithium hydroxide, which has the advantages of continuous carbonization, online switching between anti-clogging and anti-scaling, high efficiency and energy saving, tail gas recovery and stable high production, in order to solve the problems of easy scaling and clogging, intermittent inefficiency of equipment, low carbon dioxide utilization rate and unstable products in the prior art.

[0006] To achieve the above objectives, this application adopts the following technical solution: a continuous lithium hydroxide carbonization reactor, comprising: A carbonization tower, wherein the top of the carbonization tower is provided with a feed inlet, a tail gas outlet and a circulation reflux outlet, and the bottom of the carbonization tower is provided with a discharge outlet; The feed preheating unit is connected to the feed inlet; A circulating mixing unit is connected to both the circulating return port and the discharge port. The exhaust gas recovery unit is connected to the exhaust gas outlet; The discharge anti-clogging unit includes a filter screen installed inside the discharge port; The discharge transfer unit includes a discharge transfer tank connected to the carbonization tower and a carbonization transfer discharge pump; A gas distribution unit for introducing carbon dioxide into the inner cavity of the carbonization tower includes a connecting pipeline between the carbon dioxide inlet, the carbonization tower body, and the feed buffer tank.

[0007] Preferably, the preheating unit includes a primary preheater, a secondary preheater, a feed buffer tank, and a carbonization feed pump. The primary preheater uses lithium-ion mother liquor for heat exchange, and the secondary preheater uses saturated steam or cooling water for heat exchange. The feed buffer tank is also used to absorb the tail gas produced from the carbonization tower and is connected to the tail gas discharge port. The carbonization feed pump is used to connect the feed buffer tank and the feed port and to directly transport the lithium hydroxide solution after heat exchange in the feed buffer tank to the carbonization tower.

[0008] Preferably, the top of the carbonization tower cavity is equipped with a tower top diversion mechanism communicating with the feed inlet. The tower top diversion mechanism includes a guide tube, a diversion plate, and a diversion cylinder. The guide tube is horn-shaped. The diversion plate is used to connect the guide tube and the diversion cylinder. Multiple sets of annular channels are formed between the guide tube and the diversion cylinder. The surfaces of the guide tube, the diversion cylinder, and the diversion plate are all provided with an anti-sticking inner lining layer.

[0009] Preferably, the circulating stirring unit includes a circulating pump and a carbonization discharge pump externally located in the carbonization tower. The carbonization discharge pump is used to connect the discharge port, the circulating return port and the discharge transfer tank. The circulating pump is used to directly connect the discharge port and the inner cavity of the carbonization tower to form a forced circulating flow field from top to bottom inside the carbonization tower, replacing mechanical stirring.

[0010] Preferably, the exhaust gas recovery unit includes a condenser, which is connected to the exhaust gas outlet and also to the feed buffer tank.

[0011] Preferably, the filter screen is made of one or more of the following materials: stainless steel, Hastelloy, Monel alloy, titanium alloy, nickel-based alloy, polytetrafluoroethylene, ceramic, and duplex steel.

[0012] Preferably, the carbonization towers are configured as three groups connected in parallel, and each group of carbonization towers is connected to the discharge transfer tank.

[0013] Preferably, the inner wall of the carbonization tower is provided with a heat exchange layer, which is used to circulate cooling water.

[0014] Preferably, the discharge transfer tank is connected to the carbonization transfer discharge pump, and the carbonization tower is configured as three sets in parallel, adopting an online switching operation mode of two on and one on standby.

[0015] The beneficial effects of this invention are as follows: This invention replaces traditional mechanical stirring with an external circulating flow field, effectively reducing dead zones and material deposition within the reactor, and lowering the risk of scaling and clogging. Simultaneously, a top-of-tower diversion mechanism diffuses the lithium hydroxide solution entering the carbonization tower, achieving uniform and stable gas-liquid contact, thus improving carbonization reaction efficiency and carbon dioxide utilization. The exhaust gas undergoes secondary absorption in the feed buffer tank and then dehumidification via a condenser, not only improving raw material gas recovery efficiency but also achieving clean emissions. A filter screen at the discharge port prevents the formation of hard scale deposits, and the multi-tower parallel online switching mode ensures long-term continuous and stable operation of the unit, comprehensively improving the system's automation level, operational stability, and production efficiency. Attached Figure Description

[0016] The accompanying drawings, which form part of this specification, illustrate embodiments disclosed in this application and, together with the specification, serve to explain the principles of this application in a clear and understandable manner.

[0017] This disclosure will become clearer with reference to the accompanying drawings and the following detailed description, wherein: Figure 1 This is a schematic diagram of the overall structure of the present invention. Figure 2 For the present invention Figure 1 Enlarged schematic diagram of the structure at point A; Figure 3 For the present invention Figure 1 Enlarged schematic diagram of the structure at point B; Figure 4 This is a partial cross-sectional view of the interior of the carbonization tower of the present invention; Figure 5 This is a schematic diagram of the internal structure of the top flow diversion mechanism of the present invention.

[0018] The components are as follows: 1. Primary preheater; 2. Secondary preheater; 3. Feed buffer tank; 4. Condenser; 5. Carbonization feed pump; 6. Carbonization tower; 61. Feed inlet; 62. Discharge outlet; 63. Tail gas discharge outlet; 64. Circulation return outlet; 65. Air inlet; 66. Guide tube; 67. Flow divider; 68. Flow divider; 69. Filter screen; 7. Circulation pump; 8. Carbonization discharge pump; 9. Discharge transfer tank; 10. Carbonization transfer discharge pump. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0020] Please see Figures 1-5 This embodiment discloses a continuous lithium hydroxide carbonization reactor, comprising: The carbonization tower 6 has a feed inlet 61, a tail gas outlet 63 and a circulation return outlet 64 at the top, and a discharge outlet 62 at the bottom. A feed preheating unit is connected to the feed inlet 61; A circulating stirring unit is connected to the circulating return port 64 and the discharge port 62, respectively. An exhaust gas recovery unit is connected to the exhaust gas outlet 63; The discharge anti-blocking unit includes a filter screen 69 disposed inside the discharge port 62; The discharge transfer unit includes a discharge transfer tank 9 connected to the carbonization tower 6 and a carbonization transfer discharge pump 10. The gas distribution unit is used to introduce carbon dioxide into the inner cavity of the carbonization tower 6, and includes a connecting pipeline connecting the carbon dioxide inlet, the carbonization tower 6 body and the feed buffer tank 3.

[0021] This redesigned device boasts advantages such as continuous carbonization, anti-clogging and anti-scaling, high efficiency and energy saving, exhaust gas recovery, and stable high production. Its main features are: The lithium hydroxide solution in the carbonization tower 6 is circulated and pumped through an external circulating stirring unit, namely the circulating pump 7 and the carbonization discharge pump 8 connected to the carbonization tower 6. This creates a forced circulating flow field inside the carbonization tower 6, replacing the traditional mechanical stirring structure and eliminating the stirring shaft and mechanical seal. This avoids problems such as seal leakage, equipment wear and material contamination from the source. At the same time, it eliminates the stirring dead zone, significantly reduces the tendency of lithium carbonate crystal deposition and scaling on the inner wall of the equipment, and extends the continuous operation cycle.

[0022] Secondly, by utilizing the top diversion mechanism at the top of the inner cavity of the carbonization tower 6, the lithium hydroxide solution entering the device through the feed inlet 61 is guided to fully expand, and the diversion through the diversion plate 67 and the diversion cylinder 68 greatly increases the contact area between the lithium hydroxide solution and carbon dioxide, thereby increasing the reaction rate.

[0023] Furthermore, the exhaust gas first enters the feed buffer tank 3 for absorption, and then passes through the condenser 4 for dehumidification, so that unreacted carbon dioxide is fully recovered and utilized, which greatly improves gas utilization, reduces raw material consumption, and achieves clean exhaust gas emission, making it more energy-efficient and environmentally friendly.

[0024] Finally, by setting a filter screen 69 at the bottom of the discharge port 62 to block the hardened crystal deposits, and in conjunction with the multi-tower parallel operation mode with two operating and one backup, various pipe and pump blockages are avoided, and online switching and online cleaning are supported, further improving system stability, reducing maintenance costs and manual operation intensity.

[0025] In this embodiment, the preheating unit includes a primary preheater 1, a secondary preheater 2, a feed buffer tank 3, and a carbonization feed pump 5. The primary preheater 1 uses lithium-ion hot mother liquor for heat exchange, and the secondary preheater 2 uses saturated steam or cooling water for heat exchange. The feed buffer tank 3 is also used to absorb the tail gas produced from the carbonization tower 6 and is connected to the tail gas discharge port 63. The carbonization feed pump 5 is used to connect the feed buffer tank 3 and the feed port 61 and is used to directly transport the lithium hydroxide solution after heat exchange in the feed buffer tank 3 to the carbonization tower 6.

[0026] The preheating unit is used to preheat the lithium hydroxide solution so that it can quickly reach the temperature required for efficient carbonization. After preheating, the lithium hydroxide solution can enter the carbonization tower 6 under the delivery of the carbonization feed pump 5.

[0027] In this embodiment, a top diversion mechanism communicating with the feed inlet 61 is installed at the top of the inner cavity of the carbonization tower 6. The top diversion mechanism includes a guide cylinder 66, a diversion plate 67, and a diversion cylinder 68. The guide cylinder 66 is trumpet-shaped. The diversion plate 67 is used to connect the guide cylinder 66 and the diversion cylinder 68. Multiple sets of annular channels are formed between the guide cylinder 66 and the diversion cylinder 68. The surfaces of the guide cylinder 66, the diversion cylinder 68, and the diversion plate 67 are all provided with an anti-sticking inner lining layer.

[0028] The top diversion mechanism consists of a guide tube 66, a diversion tube 68, and a diversion plate 67. It diverts the lithium hydroxide solution entering the carbonization tower 6. The surface of the mechanism is provided with an anti-stick lining layer to prevent scaling of the solution. Through the diversion of the guide tube 66, the diversion tube 68, and the diversion plate 67, the lithium hydroxide solution can increase its contact area with carbon dioxide, thereby improving the efficiency of the entire carbonization reaction.

[0029] In this embodiment, the circulating stirring unit includes a circulating pump 7 and a carbonization discharge pump 8 externally placed in the carbonization tower 6. The carbonization discharge pump 8 is used to connect the discharge port 62, the circulating return port 64 and the discharge transfer tank 9. The circulating pump 7 is used to directly connect the discharge port 62 and the inner cavity of the carbonization tower 6 to form a forced circulating flow field from top to bottom inside the carbonization tower 6, replacing mechanical stirring. The circulating stirring unit utilizes the circulating pump 7 and the carbonization discharge pump 8 to directly drive the flow and form a forced circulating flow field, thereby avoiding problems such as sealing leakage, equipment wear and material contamination from the source. At the same time, it eliminates the stirring dead zone and significantly reduces the tendency of lithium carbonate crystal deposition and scaling on the inner wall of the equipment.

[0030] In this embodiment, the exhaust gas recovery unit includes a condenser 4, which is connected to the exhaust gas outlet 63 and also connected to the feed buffer tank 3.

[0031] The exhaust gas recovery unit is used to process carbon dioxide that has not yet been consumed and to directly discharge or recycle the carbon dioxide through dehumidification.

[0032] In this embodiment, the filter screen 69 is made of one or more combinations of stainless steel, Hastelloy, Monel alloy, titanium alloy, nickel-based alloy, polytetrafluoroethylene, ceramic, and duplex steel.

[0033] like Figure 4 As shown, filter screen 69 can be used to filter crystalline or lumpy materials in a solution, thereby achieving the function of filtration.

[0034] In this embodiment, the carbonization towers 6 are configured as three groups connected in parallel, and each group of carbonization towers 6 is connected to the discharge transfer tank 9.

[0035] The carbonization tower 6 is configured as three sets connected in parallel. This design allows the entire unit to operate with two units on standby and one unit on standby, thereby enabling online cleaning of the carbonization tower 6.

[0036] In this embodiment, the inner wall of the carbonization tower 6 is provided with a heat exchange layer, which is used to circulate cooling water. The heat exchange layer on the inner wall of carbonization tower 6 is mainly used to connect the circulating cooling water to exchange heat with the reaction solution inside carbonization tower 6, ensuring the normal temperature of the reaction.

[0037] In this embodiment, the discharge transfer tank 9 is connected to the carbonization transfer discharge pump 10, and the carbonization tower 6 is set as three sets in parallel, and adopts an online switching operation mode of two on and one on standby. The three sets of carbonization towers in this device, combined with the multi-tower parallel operation and the two-on-one-backup operation mode, can effectively avoid various pipe and pump blockages, support online switching and online cleaning, further improve system stability, reduce maintenance costs and manual operation intensity.

[0038] Working principle: In operation, as shown in Figure 1, the lithium hydroxide solution from the front end exchanges heat with the lithium precipitation mother liquor through the primary preheater 1, and then exchanges heat with saturated steam through the secondary preheater 2 to raise its temperature. When cooling is required, it can be switched to circulating cooling water to cool down before entering the feed buffer tank 3. Then, it is transported to different carbonization towers 6 by the carbonization feed pump 5. The lithium hydroxide solution enters the top diversion mechanism of the tower from the feed inlet 61, as shown in Figure 1. Figure 4As shown, the annular area formed between the guide tube 66 and the diverter tube 68 guides the lithium hydroxide solution, allowing it to diffuse in the carbonization tower 6 and increase the contact area with carbon dioxide, thereby improving the reaction efficiency. Subsequently, the lithium hydroxide solution flows to the bottom of the inner cavity of the carbonization tower 6, and is then transported to the discharge transfer tank 9 by the carbonization discharge pump 8, and finally to the next process by the carbonization transfer discharge pump 10. Then, the gas distribution unit introduces carbon dioxide gas into the interior of the carbonization tower 6 through the gas inlet 65, so that the lithium hydroxide solution reacts fully with the carbon dioxide. The tail gas, which is the excess carbon dioxide that has not yet been consumed in the reaction, rises through the tail gas outlet 63 and enters the feed buffer tank 3 for absorption. The condensed gas is discharged after being dehumidified by the condenser 4. The lithium hydroxide solution that has been carbonized in the carbonization tower 6 is directly circulated back into the carbonization tower 6 by the circulation pump 7. A portion of the carbonized lithium hydroxide solution is circulated back into the carbonization tower 6 through the carbonization discharge pump 8 along the circulation return port 64. This is used to form a forced circulation flow field from top to bottom inside the carbonization tower 6, replacing mechanical stirring, improving the reaction efficiency of the lithium hydroxide solution and carbon dioxide, reducing the mechanical wear of the equipment, and keeping the gas inside the carbonization tower 6 in a flowing state.

[0039] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A continuous reactor for the carbonization of lithium hydroxide, characterized in that, include: The carbonization tower (6) has a feed inlet (61), a tail gas discharge outlet (63) and a circulation return outlet (64) at the top, and a discharge outlet (62) at the bottom. A feed preheating unit is connected to the feed inlet (61); The circulating stirring unit is connected to the circulating return port (64) and the discharge port (62) respectively; The exhaust gas recovery unit is connected to the exhaust gas outlet (63); The discharge anti-blocking unit includes a filter screen (69) disposed inside the discharge port (62). The discharge transfer unit includes a discharge transfer tank (9) connected to the carbonization tower (6) and a carbonization transfer discharge pump (10). The gas distribution unit is used to introduce carbon dioxide into the inner cavity of the carbonization tower (6), and includes a connecting pipe connecting the carbon dioxide inlet, the carbonization tower (6) body and the feed buffer tank (3).

2. The lithium hydroxide carbonization continuous reactor according to claim 1, characterized in that, The preheating unit includes a primary preheater (1), a secondary preheater (2), a feed buffer tank (3), and a carbonization feed pump (5). The primary preheater (1) uses lithium-ion mother liquor for heat exchange, and the secondary preheater (2) uses saturated steam or cooling water for heat exchange. The feed buffer tank (3) is used to absorb the tail gas produced from the carbonization tower (6) and is connected to the tail gas discharge port (63). The carbonization feed pump (5) is used to connect the feed buffer tank (3) and the feed port (61).

3. A continuous lithium hydroxide carbonization reactor according to claim 2, characterized in that, The top of the inner cavity of the carbonization tower (6) is equipped with a tower top diversion mechanism that communicates with the feed inlet (61). The tower top diversion mechanism includes a guide cylinder (66), a diversion plate (67), and a diversion cylinder (68). The guide cylinder (66) is horn-shaped. The diversion plate (67) is used to connect the guide cylinder (66) and the diversion cylinder (68). Multiple sets of annular channels are formed between the guide cylinder (66) and the diversion cylinder (68). The surfaces of the guide cylinder (66), the diversion cylinder (68), and the diversion plate (67) are all provided with an anti-sticking inner lining layer.

4. A continuous lithium hydroxide carbonization reactor according to claim 3, characterized in that, The circulating stirring unit includes a circulating pump (7) and a carbonization discharge pump (8) externally placed in the carbonization tower (6). The carbonization discharge pump (8) is used to connect the discharge port (62), the circulating return port (64) and the discharge transfer tank (9). The circulating pump (7) is used to directly connect the discharge port (62) and the inner cavity of the carbonization tower (6).

5. A continuous lithium hydroxide carbonization reactor according to claim 4, characterized in that, The exhaust gas recovery unit includes a condenser (4), which is connected to the exhaust gas outlet (63) and is also connected to the feed buffer tank (3).

6. A continuous lithium hydroxide carbonization reactor according to claim 5, characterized in that, The filter screen (69) is made of one or more of the following materials: stainless steel, Hastelloy, Monel alloy, titanium alloy, nickel-based alloy, polytetrafluoroethylene, ceramic, and duplex steel.

7. A continuous lithium hydroxide carbonization reactor according to claim 6, characterized in that, The carbonization towers (6) are configured as three groups in parallel, and each group of carbonization towers (6) is connected to the discharge transfer tank (9).

8. A continuous lithium hydroxide carbonization reactor according to claim 7, characterized in that, The inner wall of the carbonization tower (6) is provided with a heat exchange layer, which is used to circulate cooling water.

9. A continuous lithium hydroxide carbonization reactor according to claim 8, characterized in that, The discharge transfer tank (9) is connected to the carbonization transfer discharge pump (10), and the carbonization tower (6) is set as three sets in parallel, and adopts an online switching operation mode of two on and one on standby.

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