Continuous leaching reaction device for lithium carbonate

Abstract

The invention relates to a continuous leaching reaction device for lithium carbonate, which is characterized by comprising a slurry tank, a chemical cleaning and flushing water tank, a discharging tank, a discharging pipeline, a feeding pipeline, a plurality of slurry heat exchangers and a plurality of leaching reactors connected in sequence, the slurry heat exchangers are defined as a first slurry heat exchanger, a second slurry heat exchanger... an Nth slurry heat exchanger, the leaching reactors are defined as a first leaching reactor, a second leaching reactor... an Lth leaching reactor, and N and L are positive integers not smaller than 3; the pipe paths of the first slurry heat exchanger, the second slurry heat exchanger... the Nth slurry heat exchanger are sequentially connected to the feeding pipeline in series, the discharging end of the feeding pipeline is connected with the first leaching reactor, and the leaching reaction device further comprises a heating device connected with the first leaching reactor; the method solves the problem of scabbing of the heat exchange surface in the lithium-containing slurry heating process, and avoids the problem of saturated precipitation of lithium carbonate in the lithium carbonate leachate waste heat utilization process.

Description

Technical Field

[0001] The invention relates to the field of metallurgy and chemical industry, and in particular to a lithium carbonate continuous leaching reaction device. Background Art

[0002] In recent years, with the increasing demand for lithium in industries such as lithium batteries, grease, and tire rubber, as well as the growing demand for lithium and its alloys in high-tech fields such as aerospace, aviation, and nuclear energy, the output of metallic lithium has also continued to grow. Lithium carbonate is the basic material for the production of secondary lithium salts and metallic lithium, and is the most basic and important product in the lithium industry. Lithium carbonate is widely used in many fields such as electronic materials, chemistry, medicine, industrial ceramics, and metallurgy. With the rapid development of high-tech industries such as information technology, electric vehicles, and green energy, the market demand for lithium and its compounds has increased dramatically, and the demand has been in short supply, and the price remains high.

[0003] In the Bayer process of alumina production, about 80% of lithium enters the solution during the Bayer process. Alumina is the raw material for aluminum electrolysis. Long-term use of alumina with a high lithium content will have a serious impact on the aluminum electrolysis process, such as reduced electrolysis temperature, deterioration of furnace regularity, reduced electrolysis production stability, reduced current efficiency, and increased energy consumption. Efficient recycling of lithium resources in the alumina production process not only helps to improve the quality of alumina products and eliminate adverse effects on downstream aluminum electrolysis, but also opens up new ways for the economic and efficient utilization of low-grade lithium-rich bauxite. Patents CN 115124052 A A method for preparing battery-grade lithium carbonate and CN 107500318 A A method for extracting lithium carbonate from sodium aluminate solution in an alumina plant disclose methods for extracting lithium carbonate from the alumina production process. Both use a process of first adsorbing lithium in the alumina production process onto aluminum hydroxide solids and then performing high-temperature wet leaching. Due to the early stage of industrialization of this technology, there is no report on a complete set of equipment for removing lithium carbonate from lithium-rich solids into solution.

[0004] The spodumene soda pressure cooking process is a method for preparing lithium carbonate from spodumene proposed in the 1960s. It mainly involves reacting β-spodumene with a sodium carbonate solution at a relatively high temperature and pressure. The lithium in the spodumene is replaced by the sodium ions in the solution and precipitated in the form of lithium carbonate. The insoluble lithium carbonate generated by the pressure cooking reaction is converted into lithium bicarbonate through a carbonization reaction, which is dissolved in water and separated from the reaction residue (sodalite). Finally, the lithium bicarbonate is converted into lithium carbonate by heating and precipitated. The soda pressure cooking process has a short production process, a small material flow rate during the production process, high product purity, and low corrosion to equipment during the process. However, so far, there has been no report on the application of this technology in industrial practice, nor a mature set of processes and equipment for soda pressure cooking and leaching lithium carbonate.

[0005] The spodumene soda pressure cooking method is used to leach lithium carbonate, and the lithium-containing aluminum hydroxide is used to leach lithium carbonate. The main purpose of the leaching process is to leach the lithium in the slurry to form a lithium-containing solution, which provides the raw material basis for subsequent liquid-solid separation, impurity removal and other processes.

[0006] The traditional leaching device is mainly similar to the pipeline dissolution device in the alumina industry. The lithium-containing raw ore slurry is preheated by a multi-stage exhaust steam preheater. After being indirectly heated to the leaching temperature by steam, it enters the leaching reactor for heat preservation and leaching. The slurry after leaching lithium carbonate is cooled by multi-stage flash evaporation and then enters the discharge trough. The exhaust steam generated by flash evaporation is used to preheat the raw ore slurry.

[0007] The existing problems are: lithium carbonate has a low solubility, and its solubility decreases with increasing temperature. During the heating and preheating of the slurry, lithium carbonate is prone to form scars on the heat exchange surface; the leachate in the leaching reactor is mostly a saturated solution of lithium carbonate. During the flash evaporation process, the concentration of the leachate will gradually increase, and lithium carbonate will precipitate due to supersaturation, causing crystallization and blockage of the flash evaporator discharge pipe, affecting the normal operation of the system. Summary of the invention

[0008] The purpose of the present invention is to provide a pipelined continuous leaching reaction device for lithium carbonate, so as to solve the problems in the prior art of severe scarring of the heat exchange surface during the leaching of lithium carbonate from lithium-containing slurry and saturated precipitation of lithium carbonate during the utilization of waste heat of the leaching solution.

[0009] In order to solve the above technical problems, the technical solution of a pipelined continuous leaching reaction device of lithium carbonate in the present invention is as follows: A lithium carbonate continuous leaching reaction device, comprising a slurry tank, a chemical cleaning tank, a flushing water tank and a discharge tank, and also comprising a discharge pipeline and a feed pipeline. The leaching reaction device also comprises a plurality of slurry heat exchangers and a plurality of leaching reactors connected in sequence, wherein each slurry heat exchanger is defined as a first slurry heat exchanger, a second slurry heat exchanger ... an Nth slurry heat exchanger, the slurry heat exchanger is a shell-and-tube heat exchanger having a tube side and a shell side, and each leaching reactor is defined as a first leaching reactor, a second leaching reactor ... an Lth leaching reactor, N and L are positive integers not less than 3, the tube sides of the first slurry heat exchanger, the second slurry heat exchanger ... the Nth slurry heat exchanger are connected in series in sequence to the feed pipeline, and the discharge end of the feed pipeline is connected to the first The leaching reactor is connected, the leaching reaction device also includes a heating device connected to the first leaching reactor, the Nth slurry heat exchanger, the N-1th slurry heat exchanger...the shell side of the first slurry heat exchanger is serially connected to the discharge pipeline, the feed end of the discharge pipeline is connected to the discharge port of the Lth leaching reactor, the discharge end of the discharge pipeline is connected to the flushing water tank and the discharge tank through the discharge branch, each discharge branch is provided with a discharge branch switch valve, the feed end of the feed pipeline is connected to the slurry tank and the flushing water tank through the feed branch, each feed branch is provided with a feed branch switch valve, the discharge end of the feed pipeline is connected to the feed port of the first leaching reactor, and the fluid flow direction in the tube side is opposite to the fluid flow direction in the shell side.

[0010] Furthermore, the leaching reaction device also includes a chemical cleaning tank, the feed end of the feed pipeline is connected to the water outlet of the chemical cleaning tank through a feed branch, and the discharge end of the discharge pipeline is connected to the water inlet of the chemical cleaning tank through a discharge branch.

[0011] Furthermore, each feed branch line is also provided with a delivery pump, and a high-pressure feeding pump is provided on the feed pipeline upstream of the first slurry heat exchanger.

[0012] Furthermore, the delivery pump and the high-pressure feeding pump are diaphragm pumps, plunger pumps or centrifugal pumps.

[0013] Furthermore, the heating device comprises a steam buffer, which is respectively connected to the steam inlet of each leaching reactor through steam pipes arranged in parallel, and the steam heating method of the leaching reactor is direct mixing heating of steam and materials.

[0014] Further, the operating temperature of the leaching reactor is 180-260°C; Furthermore, each steam pipeline is serially connected with a steam regulating valve, a cut-off valve and a check valve.

[0015] Furthermore, each leaching reactor includes a reactor and a feed pipe and a discharge pipe connected to the reactor, the lower end of the feed pipe is located at the upper middle side of the reactor, and the lower end of the discharge pipe is located at the lower middle side of the reactor.

[0016] Furthermore, a pressure regulating valve is provided on the discharge pipeline downstream of the first slurry heat exchanger, and the pressure regulating valve is interlocked with the Lth leaching reactor, and the control condition is that the pressure of the Lth leaching reactor is achieved by the pressure regulating valve to be higher than the saturated vapor pressure of the slurry at the material working temperature by more than 0.1 MPa.

[0017] Furthermore, an isolation valve is provided on the discharge pipeline between the shell side of the Nth slurry heat exchanger and the Lth leaching reactor, a reflux pipeline is provided between the feed pipeline connected between the tube side of the Nth slurry heat exchanger and the first leaching reactor and the discharge pipeline between the shell side of the Nth slurry heat exchanger and the Lth leaching reactor, and a reflux pipeline valve is provided on the reflux pipeline.

[0018] Furthermore, each slurry heat exchanger adopts a multi-stage series shell and tube heater.

[0019] The beneficial effects of the present invention are as follows: when in use, the slurry tank contains the batching slurry containing lithium ore slurry, the lithium-containing batching slurry is transported to the first leaching reactor through the feed pipeline, and the lithium carbonate solution produced by each level of leaching reactor flows back to the discharge tank through the discharge pipeline. Under the action of the heating device, the lithium carbonate solution has residual heat, and the lithium carbonate solution flows through the tube side of the Nth slurry heat exchanger, the N-1th slurry heat exchanger... the first slurry heat exchanger in sequence, so the batching slurry flowing through the shell side of the slurry heat exchanger can be heated, and the heated batching slurry flows to the first slurry heat exchanger. The first leaching reactor increases the temperature of the lithium-containing ingredient slurry entering the leaching reactor, realizes the utilization of waste heat, and can save the energy consumption of the heating process of the leaching reactor; the saturated lithium carbonate solution discharged from the Lth leaching reactor is cooled by liquid heat exchange in the shell and tube sides. During the cooling process, the solubility of the lithium carbonate solution is increased, so it is not easy to form lithium carbonate scars in the shell side. Compared with the conventional flash evaporation to recover the leaching slurry and utilize the waste heat of flash evaporation, it can avoid the concentration of the leaching slurry during the flash evaporation process, and avoid the supersaturated precipitation of lithium carbonate and the problem of flash condensed water carrying material.

[0020] Furthermore, the solution of the present invention eliminates facilities such as a slurry flash evaporator and a condensate tank, thereby simplifying the process and reducing investment.

[0021] Furthermore, the preheated slurry is directly heated by introducing fresh steam into the reactor, which eliminates the problem of heat exchange surface scarring and greatly extends the device operation cycle. Since the solubility of lithium carbonate decreases with increasing temperature, the conventional indirect heating method has a high temperature of the heat exchange surface, and lithium carbonate is easy to crystallize on the heat exchange surface, resulting in very serious scarring of the device, making it difficult for the device to achieve long-term safe operation.

[0022] Furthermore, since the solubility of lithium carbonate increases with decreasing temperature, the temperature level of lithium carbonate slurry decreases during the preheating of raw ore slurry in the heat exchanger shell, and its solubility increases continuously. Since the temperature of the heat exchange surface is lower than the leaching slurry temperature, the solubility of lithium carbonate is higher in the area close to the heat exchange surface. Therefore, lithium carbonate scars will not form on the shell heat exchange surface.

[0023] Furthermore, during the operation of the device, other scars such as aluminum hydroxide scars and calcium silicate scars may be deposited or accumulated in the shell. These scars are difficult to remove by mechanical cleaning or hydraulic cleaning, but these scars are easy to react with acids and alkalis. The chemical cleaning method used in the present invention can dissolve the scars, thereby achieving regeneration of the heat exchange surface.

[0024] Furthermore, the clean water in the flushing tank can flush out the materials in the inner tube of the slurry heat exchanger when the device is shut down, thereby preventing the slurry heat exchanger from accumulating materials.

[0025] Furthermore, the cleaning liquid in the chemical cleaning tank can chemically clean the scars of the slurry heat exchanger to achieve regeneration of the heat exchange surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] By reading the following detailed description with reference to the accompanying drawings, the above and other objects, features and advantages of the exemplary embodiments of the present disclosure will become readily understood. In the accompanying drawings, several embodiments of the present disclosure are shown in an exemplary and non-limiting manner, and the same or corresponding reference numerals represent the same or corresponding parts, wherein: Figure 1 It is a schematic structural diagram of an embodiment of the present invention; 1. Feed pipeline; 2. Discharge pipeline; 3. High-pressure feeding pump; 4. First slurry heat exchanger; 5. Second slurry heat exchanger; 6. Nth slurry heat exchanger; 7. Pressure regulating valve; 8. Isolation valve; 9. Reflux pipeline; 10. Steam pipeline; 11. Steam buffer; 12. First leaching reactor; 13. Second leaching reactor; 14. Lth leaching reactor; 15. Feed pipe; 16. Discharge pipe; 17. Discharge branch; 18. Discharge branch switch valve; 19. Feed branch; 20. Delivery pump; 21. Feed branch switch valve; 22. Flushing water tank; 23. Discharge tank; 24. Slurry tank; 25. Chemical cleaning tank. DETAILED DESCRIPTION

[0027] In order to facilitate the understanding of the present invention, the present invention is described in more detail below in conjunction with the accompanying drawings and specific embodiments. Preferred embodiments of the present invention are provided in the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described in this specification. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0028] It should be noted that, unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0029] An embodiment of a lithium carbonate continuous leaching reaction device of the present invention is as follows: Figure 1 As shown: It includes a slurry tank 24, a chemical cleaning tank 25, a flushing tank 22 and a discharge tank 23. The flushing tank 22 is used to hold clean water, the slurry tank 24 is used to hold the batching slurry containing lithium ore slurry, and the chemical cleaning tank 25 is used to hold the cleaning liquid, such as liquid caustic soda, sulfuric acid, hydrochloric acid or nitric acid.

[0030] The lithium carbonate continuous leaching reaction device further includes a discharge pipeline 2 and a feed pipeline 1, and the leaching reaction device further includes a plurality of slurry heat exchangers and a plurality of leaching reactors connected in sequence, wherein each slurry heat exchanger is defined as a first slurry heat exchanger 4, a second slurry heat exchanger 5 ... an Nth slurry heat exchanger 6, and each leaching reactor is defined as a first leaching reactor 12, a second leaching reactor 13 ... an Lth leaching reactor 14, wherein N and L are positive integers not less than 3. The slurry heat exchanger is a shell-and-tube heat exchanger having a tube side and a shell side.

[0031] The tube path of each slurry heat exchanger is composed of a single inner tube (or multiple inner tubes connected in parallel).

[0032] The tube sides of the first slurry heat exchanger 4, the second slurry heat exchanger 5...the Nth slurry heat exchanger 6 are serially connected to the feed pipeline, and the shell sides of the Nth slurry heat exchanger 6, the N-1th slurry heat exchanger...the first slurry heat exchanger 4 are serially connected to the discharge pipeline 2.

[0033] The feed end of the feed pipeline is connected to the slurry tank 24, the flushing tank 22 and the chemical cleaning tank 25 through the feed branch 19, and each feed branch is provided with a feed branch switch valve 21, and the discharge end of the feed pipeline is connected to the feed port of the first leaching reactor 12. The feed end of the discharge pipeline 2 is connected to the discharge port of the Lth leaching reactor, and the discharge end of the discharge pipeline is connected to the flushing tank 22, the discharge tank 23 and the chemical cleaning tank 25 through the discharge branch 17, and each discharge branch is provided with a discharge branch switch valve 18.

[0034] Each feed branch is also provided with a delivery pump 20, and a high-pressure feed pump 3 is provided on the feed pipeline upstream of the first slurry heat exchanger. The delivery pump and the high-pressure feed pump are diaphragm pumps, plunger pumps or centrifugal pumps, preferably diaphragm pumps.

[0035] Each leaching reactor is a steam-heated reactor with stirring. The lithium carbonate continuous leaching reaction device also includes a heating device connected to the first leaching reactor. The heating device includes a steam buffer 11. Hot steam first enters the steam buffer. The steam buffer is connected to the steam inlet of each leaching reactor through a steam pipeline 10 arranged in parallel. A steam regulating valve, a cut-off valve and a check valve are sequentially connected in series on each steam pipeline. Each leaching reactor includes a reactor and a feed pipe 15 and a discharge pipe 16 connected to the reactor. The lower end of the feed pipe is located at the middle and upper side of the reactor, and the lower end of the discharge pipe is located at the middle and lower side of the reactor. The material enters the corresponding leaching reactor through the feed pipe and then is discharged from the corresponding leaching reactor through the discharge pipe.

[0036] A pressure regulating valve 7 is provided on the discharge pipeline downstream of the first slurry heat exchanger, and the pressure regulating valve is located between the first slurry heat exchanger 4 and the discharge tank. The pressure regulating valve is interlocked with the pressure of the L-stage leaching reactor to prevent the material in the leaching reactor from vaporizing due to high temperature and low pressure. The pressure regulating valve is interlocked with the L-stage leaching reactor, and the control condition is that the pressure of the L-stage leaching reactor is higher than the saturated vapor pressure of the slurry at the material working temperature by more than 0.1MPa through the pressure regulating valve.

[0037] An isolation valve 8 is provided on the discharge pipeline between the shell side of the Nth slurry heat exchanger and the Lth leaching reactor, and a reflux pipeline 9 is provided between the feed pipeline connected between the tube side of the Nth slurry heat exchanger and the first leaching reactor and the discharge pipeline between the shell side of the Nth slurry heat exchanger and the Lth leaching reactor. A reflux pipeline valve is provided on the reflux pipeline 9 to isolate each leaching reactor from the system during water flushing and chemical cleaning. The operating temperature of each leaching reactor is 180~260℃.

[0038] When in use, the batch slurry containing lithium ore flows through the feed pipeline and passes through the tube side of the corresponding slurry heat exchanger in sequence. The lithium carbonate solution produced by the leaching reactor passes through the shell side of the corresponding slurry heat exchanger in sequence when it flows to the discharge trough through the discharge pipeline, realizing heat exchange, increasing the temperature of the slurry entering the first leaching reactor, and recovering the waste heat of the leaching slurry at the same time, which can greatly reduce the energy consumption of the system. Compared with the conventional flash evaporation to recover the waste heat of the leaching slurry, it can avoid the supersaturated precipitation of lithium carbonate and the problem of flash condensation water carrying material during the flash evaporation process; the preheated slurry is directly heated by introducing new steam into the leaching reactor, and there is no problem of scarring on the heat exchange surface, which can greatly extend the operation cycle of the device. Because the solubility of lithium carbonate decreases with increasing temperature, the conventional indirect heating method will cause severe scarring of lithium carbonate on the heat exchange surface, making it difficult for the device to achieve long-term safe operation.

[0039] The clean water flushing device set up can flush out the materials in the slurry heat exchanger when the device is shut down to prevent material accumulation in the heat exchanger. For example, close the isolation valve and the switch valve on the feed pipe downstream of the Nth slurry heat exchanger, and the clean water passes through the first slurry heat exchanger, the second slurry heat exchanger... the Nth slurry heat exchanger in sequence, and then passes through the return pipe, and then flows through the Nth slurry heat exchanger, the N-1th slurry heat exchanger... the shell side of the first slurry heat exchanger in sequence to clean each slurry heat exchanger, and the cleaning waste liquid can flow back to the slurry tank or the discharge tank; by the same token, the chemical cleaning tank can realize chemical cleaning of each slurry heat exchanger. In actual use, each slurry heat exchanger can be cleaned with clean water separately, or each slurry heat exchanger can be chemically cleaned first, and then cleaned with clean water.

[0040] In the above description of this specification, unless otherwise clearly specified and limited, the terms "fixed", "installed", "connected" or "connected" should be understood in a broad sense. For example, with regard to the term "connection", it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal connection of two elements or the interaction relationship between two elements. Therefore, unless otherwise clearly defined in this specification, those skilled in the art can understand the specific meanings of the above terms in the present invention according to the specific circumstances.

[0041] According to the above description of this specification, those skilled in the art may also understand that the terms used below, such as "up", "down", "front", "back", "left", "right", "length", "width", "thickness", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential", "center", "longitudinal", "lateral", "clockwise" or "counterclockwise", etc., which indicate the orientation or position relationship, are based on the orientation or position relationship shown in the drawings of this specification, and are only for the purpose of facilitating the explanation of the scheme of the present invention and simplifying the description, rather than explicitly or implicitly indicating that the device or element involved must have the specific orientation, be constructed and operate in a specific orientation. Therefore, the above-mentioned orientation or position relationship terms cannot be understood or interpreted as limitations on the scheme of the present invention.

[0042] In addition, the terms "first" or "second" used in this specification to refer to numbers or ordinals are only used for descriptive purposes and cannot be understood as explicitly or implicitly indicating relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of this specification, the meaning of "plurality" is at least two, such as two, three or more, etc., unless otherwise clearly and specifically defined.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A lithium carbonate continuous leaching reaction device, characterized in that: The invention comprises a slurry tank, a chemical cleaning tank, a flushing water tank and a discharge tank, and also comprises a discharge pipeline and a feed pipeline. The leaching reaction device also comprises a plurality of slurry heat exchangers and a plurality of leaching reactors connected in sequence. It is defined that each slurry heat exchanger is respectively a first slurry heat exchanger, a second slurry heat exchanger ... an Nth slurry heat exchanger. The slurry heat exchanger is a shell-and-tube heat exchanger having a tube side and a shell side. Each leaching reactor is respectively a first leaching reactor, a second leaching reactor ... an Lth leaching reactor. N and L are positive integers not less than 3. The tube sides of the first slurry heat exchanger, the second slurry heat exchanger ... the Nth slurry heat exchanger are sequentially connected in series on the feed pipeline. The discharge end of the feed pipeline is connected to the first leaching reactor. The leaching reaction device also includes a heating device connected to the first leaching reactor, an Nth slurry heat exchanger, an N-1th slurry heat exchanger...the shell side of the first slurry heat exchanger is serially connected to the discharge pipeline, the feed end of the discharge pipeline is connected to the discharge port of the Lth leaching reactor, the discharge end of the discharge pipeline is connected to the flushing water tank and the discharge tank through the discharge branch, each discharge branch is provided with a discharge branch switch valve, the feed end of the feed pipeline is connected to the slurry tank and the flushing water tank through the feed branch, each feed branch is provided with a feed branch switch valve, the discharge end of the feed pipeline is connected to the feed port of the first leaching reactor, and the fluid flow direction in the tube side is opposite to the fluid flow direction in the shell side.

2. The lithium carbonate continuous leaching reaction device according to claim 1, characterized in that: The leaching reaction device also includes a chemical cleaning tank, the feed end of the feed pipeline is connected to the water outlet of the chemical cleaning tank through a feed branch, and the discharge end of the discharge pipeline is connected to the water inlet of the chemical cleaning tank through a discharge branch.

3. The lithium carbonate continuous leaching reaction device according to claim 1, characterized in that: Each feed branch line is also provided with a delivery pump, and a high-pressure feeding pump is provided on the feed pipeline upstream of the first slurry heat exchanger.

4. The lithium carbonate continuous leaching reaction device according to claim 3, characterized in that: The delivery pump and high-pressure feeding pump are diaphragm pumps, plunger pumps or centrifugal pumps.

5. The lithium carbonate continuous leaching reaction device according to claim 1, characterized in that: The heating device comprises a steam buffer, which is respectively connected to the steam inlet of each leaching reactor through a parallel arranged steam pipeline. The steam heating method of the leaching reactor is direct mixing heating of steam and materials.

6. The lithium carbonate continuous leaching reaction device according to claim 1, characterized in that: The operating temperature of the leaching reactor is 180-260°C.

7. The lithium carbonate continuous leaching reaction device according to claim 5, characterized in that: Each steam pipeline is serially connected with a steam regulating valve, a cut-off valve and a check valve.

8. The lithium carbonate continuous leaching reaction device according to claim 1, characterized in that: Each leaching reactor comprises a reactor and a feed pipe and a discharge pipe connected to the reactor. The lower end of the feed pipe is located at the upper middle side of the reactor, and the lower end of the discharge pipe is located at the lower middle side of the reactor.

9. The lithium carbonate continuous leaching reaction device according to claim 1, characterized in that: A pressure regulating valve is provided on the discharge pipeline downstream of the first slurry heat exchanger. The pressure regulating valve is interlocked with the Lth leaching reactor, and the control condition is that the pressure of the Lth leaching reactor is higher than the saturated vapor pressure of the slurry at the material working temperature by more than 0.1 MPa through the pressure regulating valve.

10. The lithium carbonate continuous leaching reaction device according to any one of claims 1 to 9, characterized in that: An isolation valve is provided on the discharge pipeline between the shell side of the Nth slurry heat exchanger and the Lth leaching reactor, a reflux pipeline is provided between the feed pipeline connected between the tube side of the Nth slurry heat exchanger and the first leaching reactor and the discharge pipeline between the shell side of the Nth slurry heat exchanger and the Lth leaching reactor, and a reflux pipeline valve is provided on the reflux pipeline.

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