Device for efficiently and comprehensively utilizing waste heat of lithium precipitation mother liquor

Abstract

The invention belongs to the technical field of waste heat recycling, and particularly discloses a lithium precipitation mother liquor waste heat efficient comprehensive utilization device which comprises a high-temperature lithium precipitation mother liquor storage tank, and the outlet end of the high-temperature lithium precipitation mother liquor storage tank is connected with a high-purity water heat exchange structure and a sodium carbonate heat exchange structure in parallel; the high-purity water heat exchange structure is communicated with a washing heat exchange structure; the sodium carbonate heat exchange structure is communicated with a refined liquid heat exchange structure, and liquid in the high-temperature lithium precipitation mother liquid storage tank is fed into the low-temperature lithium precipitation mother liquid storage tank after heat exchange. The method is applied to lithium precipitation mother liquor waste heat recycling in the battery-grade lithium carbonate production process, efficient utilization of the lithium precipitation mother liquor waste heat is achieved, and the energy consumption in the lithium carbonate production process is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of waste heat recovery and utilization, and specifically discloses a device for efficient comprehensive utilization of waste heat from lithium precipitation mother liquor. Background Art

[0002] In the field of producing lithium carbonate from salt lake brine, refined lithium chloride solution reacts with sodium carbonate solution to form lithium carbonate, which is then separated according to different solubilities. During the production process, to ensure high-quality product quality, a large amount of steam heating is required for process media and raw materials such as high-purity water, washing water, soda solution, and refined solution to guarantee the process stability of continuous production. Especially in the salt lake area, the average temperature is low and the temperature difference between day and night is large. Steam, as a heat source, is particularly important. The salt lake is located in the desert with harsh natural conditions, resulting in a relatively high steam price and a large steam consumption, thus significantly increasing the energy use and further increasing the cost of lithium extraction from the salt lake. Especially in winter, under the influence of ensuring balanced gas use, emission reduction and limit, and the "coal-to-gas" reform in the north, the gas consumption of enterprises in winter is strictly controlled. To ensure normal and high-quality production in winter, the rational utilization of heat energy affects the high-quality development of enterprises.

[0003] As the filtrate after the reaction of lithium chloride and sodium carbonate to form lithium carbonate, the lithium precipitation mother liquor has a high temperature and a large output as a by-product. The lithium content in the mother liquor exceeds 1 g / L and the temperature exceeds 70 °C. If directly treated, it will cause waste of lithium resources and heat, which does not meet the requirements of cost reduction, efficiency increase and efficient comprehensive utilization of resources. The utility model patent CN217025368U proposes a device for recovering waste heat from lithium precipitation mother liquor in a lithium carbonate system. This utility model uses the lithium precipitation mother liquor to exchange heat with lithium-rich brine to heat the lithium-rich brine, thereby recovering the heat of the lithium precipitation mother liquor. This set of devices can achieve the purpose of recovering waste heat from the lithium precipitation mother liquor. However, due to the characteristics of the device, it cannot reach a high heat utilization rate, and there is still waste of heat. There is still a large room for development in reducing energy consumption and further reducing production costs. Summary of the Invention

[0004] The purpose of the present invention is to provide a device for efficient comprehensive utilization of waste heat from lithium precipitation mother liquor to solve the above problems, which is applied to the recovery and utilization of waste heat from lithium precipitation mother liquor in the production process of battery-grade lithium carbonate, realizing the efficient utilization of waste heat from lithium precipitation mother liquor to reduce the energy consumption in the production process of lithium carbonate.

[0005] To achieve the above purpose, the present invention provides the following solutions:

[0006] A device for highly efficient comprehensive utilization of waste heat from lithium precipitation mother liquor, including a high-temperature lithium precipitation mother liquor storage tank. The outlet end of the high-temperature lithium precipitation mother liquor storage tank is connected in parallel with a high-purity water heat exchange structure and a soda ash heat exchange structure. The high-purity water heat exchange structure is connected to a water washing heat exchange structure. The soda ash heat exchange structure is connected to a refined liquid heat exchange structure. The liquid in the high-temperature lithium precipitation mother liquor storage tank is sent to a low-temperature lithium precipitation mother liquor storage tank after heat exchange.

[0007] Preferably, the high-purity water heat exchange structure includes a first high-purity water heat exchanger and a second high-purity water heat exchanger. The refrigerant inlet of the first high-purity water heat exchanger is connected to a low-temperature high-purity water tank. The refrigerant inlet end of the second high-purity water heat exchanger is connected in series to the refrigerant outlet end of the first high-purity water heat exchanger. The liquid outlet of the high-temperature lithium precipitation mother liquor storage tank is connected in parallel to the heat medium inlets of the first high-purity water heat exchanger and the second high-purity water heat exchanger respectively.

[0008] Preferably, the soda ash heat exchange structure includes a second soda ash liquid heat exchanger and a first soda ash liquid heat exchanger. The refrigerant inlet of the first soda ash liquid heat exchanger is connected to a low-temperature soda ash liquid storage tank. The refrigerant inlet end of the second soda ash liquid heat exchanger is connected in series to the refrigerant pipeline outlet end of the first soda ash liquid heat exchanger. The liquid outlet of the high-temperature lithium precipitation mother liquor storage tank is connected in parallel to the heat medium inlets of the second soda ash liquid heat exchanger and the first soda ash liquid heat exchanger respectively.

[0009] Preferably, the water washing heat exchange structure includes a water washing water heat exchanger. The heat medium inlets of the water washing water heat exchanger are connected in parallel to the heat medium outlets of the first high-purity water heat exchanger and the second high-purity water heat exchanger respectively. The refrigerant inlet of the water washing water heat exchanger is connected to a water washing water tank.

[0010] Preferably, the refined liquid heat exchange structure includes a refined liquid heat exchanger. The heat medium inlets of the refined liquid heat exchanger are connected in parallel to the heat medium outlets of the second soda ash liquid heat exchanger and the first soda ash liquid heat exchanger respectively. The refrigerant inlet of the refined liquid heat exchanger is connected to a low-temperature refined liquid storage tank.

[0011] Preferably, the refrigerant outlet of the second high-purity water heat exchanger is connected to a high-temperature high-purity water tank.

[0012] Preferably, the refrigerant outlet of the second soda ash liquid heat exchanger is connected to a high-temperature soda ash liquid storage tank.

[0013] Preferably, the refrigerant outlet of the refined liquid heat exchanger is connected to a high-temperature refined liquid storage tank.

[0014] The present invention has the following technical effects:

[0015] In the present invention, the high-efficiency comprehensive device for waste heat of lithium precipitation mother liquor can efficiently utilize waste heat to preheat various process media and process raw materials, greatly broadening the heat exchange network, increasing the waste heat utilization efficiency. Heating the process media and process raw materials can greatly reduce the use of process steam, which conforms to the characteristics of energy conservation and consumption reduction. In addition, the high-efficiency comprehensive utilization device for waste heat of lithium precipitation mother liquor described in the present invention only generates a small amount of power transportation energy consumption and does not generate waste water or waste gas. The device provided by the present invention can effectively reduce the temperature of the lithium precipitation mother liquor, and the cooled lithium precipitation mother liquor can be directly reused to generate economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0017] Figure 1 It is a schematic structural diagram of the present invention.

[0018] Among them, 1. High-temperature lithium precipitation mother liquor storage tank; 2. Low-temperature lithium precipitation mother liquor storage tank; 3. High-purity water heat exchanger I; 4. High-purity water heat exchanger II; 5. Washing water heat exchanger; 6. Soda ash solution heat exchanger II; 7. Soda ash solution heat exchanger I; 8. Refined liquid heat exchanger; 9. Low-temperature high-purity water tank; 10. High-temperature high-purity water tank; 11. Washing water tank; 12. Low-temperature soda ash solution storage tank; 13. High-temperature soda ash solution storage tank; 14. Low-temperature refined liquid storage tank; 15. High-temperature refined liquid storage tank. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0020] In order to make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below with reference to the drawings and specific embodiments.

[0021] Refer to Figure 1As shown in the figure, this embodiment provides a device for efficient comprehensive utilization of waste heat from lithium precipitation mother liquor, including a high-temperature lithium precipitation mother liquor storage tank 1. The outlet end of the high-temperature lithium precipitation mother liquor storage tank 1 is connected in parallel with a high-purity water heat exchange structure and a soda ash heat exchange structure; the high-purity water heat exchange structure is connected to a water washing heat exchange structure; the soda ash heat exchange structure is connected to a refined liquid heat exchange structure. The liquid in the high-temperature lithium precipitation mother liquor storage tank 1 is sent to a low-temperature lithium precipitation mother liquor storage tank 2 after heat exchange.

[0022] In a further optimized solution, the high-purity water heat exchange structure includes a first high-purity water heat exchanger 3 and a second high-purity water heat exchanger 4. The refrigerant inlet of the first high-purity water heat exchanger 3 is connected to a low-temperature high-purity water tank 9. The refrigerant inlet end of the second high-purity water heat exchanger 4 is connected in series to the refrigerant outlet end of the first high-purity water heat exchanger 3. The liquid outlet of the high-temperature lithium precipitation mother liquor storage tank 1 is connected in parallel to the heat medium inlets of the first high-purity water heat exchanger 3 and the second high-purity water heat exchanger 4 respectively.

[0023] In a further optimized solution, the soda ash heat exchange structure includes a second soda ash liquid heat exchanger 6 and a first soda ash liquid heat exchanger 7. The refrigerant inlet of the first soda ash liquid heat exchanger 7 is connected to a low-temperature soda ash liquid storage tank 12. The refrigerant inlet end of the second soda ash liquid heat exchanger 6 is connected in series to the refrigerant pipeline outlet end of the first soda ash liquid heat exchanger 7. The liquid outlet of the high-temperature lithium precipitation mother liquor storage tank 1 is connected in parallel to the heat medium inlets of the second soda ash liquid heat exchanger 6 and the first soda ash liquid heat exchanger 7 respectively.

[0024] In a further optimized solution, the water washing heat exchange structure includes a water washing water heat exchanger 5. The heat medium inlet of the water washing water heat exchanger 5 is connected in parallel to the heat medium outlets of the first high-purity water heat exchanger 3 and the second high-purity water heat exchanger 4 respectively. The refrigerant inlet of the water washing water heat exchanger 5 is connected to a water washing water tank 11.

[0025] In a further optimized solution, the refined liquid heat exchange structure includes a refined liquid heat exchanger 8. The heat medium inlet of the refined liquid heat exchanger 8 is connected in parallel to the heat medium outlets of the second soda ash liquid heat exchanger 6 and the first soda ash liquid heat exchanger 7 respectively. The refrigerant inlet of the refined liquid heat exchanger 8 is connected to a low-temperature refined liquid storage tank 14.

[0026] In a further optimized solution, the refrigerant outlet of the second high-purity water heat exchanger 4 is connected to a high-temperature high-purity water tank 10.

[0027] In a further optimized solution, the refrigerant outlet of the second soda ash liquid heat exchanger 6 is connected to a high-temperature soda ash liquid storage tank 13.

[0028] In a further optimized solution, the refrigerant outlet of the refined liquid heat exchanger 8 is connected to a high-temperature refined liquid storage tank 15.

[0029] The first heat exchange system consists of equipment such as the high-temperature lithium precipitation mother liquor storage tank 1, the high-purity water heat exchanger 1, the high-purity water heat exchanger 2, the washing water heat exchanger 5, the low-temperature high-purity water tank 9, the high-temperature high-purity water tank 10, the washing water tank 11, and auxiliary pipelines. The second heat exchange system consists of equipment such as the high-temperature lithium precipitation mother liquor storage tank 1, the soda ash solution heat exchanger 2, the soda ash solution heat exchanger 1, the refined liquid heat exchanger 8, the low-temperature soda ash solution storage tank 12, the high-temperature soda ash solution storage tank 13, the low-temperature refined liquid storage tank 14, the high-temperature refined liquid storage tank 15, and auxiliary pipelines.

[0030] Both of the two heat exchange systems use the lithium precipitation mother liquor as the heat medium. The two heat exchange systems can operate independently. The first system uses high-purity water and washing water as the heat sources to be heated, and the second system uses soda ash solution and refined liquid as the heat sources to be heated.

[0031] Taking the lithium precipitation mother liquor as the heat source, it is transported from the outlet of the high-temperature lithium precipitation mother liquor storage tank 1 to the high-purity water heat exchanger 1, the high-purity water heat exchanger 2, the soda ash solution heat exchanger 2, and the soda ash solution heat exchanger 1. The lithium precipitation mother liquor flows in from the upper part and out from the lower part of the heat exchanger to conduct countercurrent heat exchange with the cold source, realizing the waste heat utilization of the first-stage lithium precipitation mother liquor.

[0032] The high-purity water heat exchanger 1 and the high-purity water heat exchanger 2 are in parallel. High-purity water, as the cold source, is connected to the cold source interface of the high-purity water heat exchanger 1 through the outlet of the low-temperature high-purity water tank 9 and is connected in series and countercurrently with the high-purity water heat exchanger 2. After two-stage heat exchange, the high-purity water is transported to the high-temperature high-purity water tank 10. A steam pipeline mixer is connected to the inlet pipeline of the high-temperature high-purity water tank 10, and a steam regulating valve and a thermometer are configured to realize the temperature adjustment of the high-purity water.

[0033] The soda ash solution heat exchanger 2 and the soda ash solution heat exchanger 1 are also in parallel. The soda ash solution, as the heat source to be heated, is connected to the cold source interface of the soda ash solution heat exchanger 1 through the outlet of the low-temperature soda ash solution storage tank 12 and is connected in series and countercurrently with the soda ash solution heat exchanger 2. After two-stage heat exchange, the soda ash solution is transported to the high-temperature soda ash solution storage tank 13. A steam pipeline mixer is also connected to the inlet pipeline of the high-temperature soda ash solution storage tank 13, and a steam regulating valve and a thermometer are configured to realize the temperature adjustment of the soda ash solution.

[0034] In the first heat exchange system, the outlets of the two parallel high-purity water heat exchangers are connected to the inlet pipeline of the washing water heat exchanger 5. The washing water, as the cold source, enters the washing water heat exchanger 5 through the outlet of the washing water tank 11. The lithium precipitation mother liquor serves as the heat source again to conduct heat exchange with the washing water through the heat exchanger, realizing the waste heat utilization of the second-stage lithium precipitation mother liquor.

[0035] In the second heat exchange system, the outlets of two parallel soda solution heat exchangers are connected to the inlet pipeline of the refined liquid heat exchanger 8. The refined liquid enters the refined liquid heat exchanger 8 as a cold source through the outlet of the low-temperature refined liquid storage tank 14, and enters the high-temperature refined liquid storage tank 15 after heat exchange. The lithium precipitation mother liquor also serves as a heat source again to exchange heat with the refined liquid through the heat exchanger, realizing the waste heat utilization of the lithium precipitation mother liquor at the second stage.

[0036] A steam pipeline mixer is also connected to the inlet pipeline of the high-temperature refined liquid storage tank 15, and a steam regulating valve and a thermometer are configured to adjust the temperature of the refined liquid.

[0037] After the secondary waste heat utilization of the lithium precipitation mother liquor through two sets of heat exchange systems, the lithium precipitation mother liquor at the outlets of the washing water heat exchanger 5 and the refined liquid heat exchanger 8 meet, and the cooled lithium precipitation mother liquor enters the low-temperature lithium precipitation mother liquor storage tank 2 for subsequent processes.

[0038] All the cold and heat source connection ports of the heat exchangers are connected by flanges. All the heat exchangers are plate heat exchangers and are provided with expansion joints.

[0039] In particular, the lithium precipitation mother liquor and the soda solution are alkaline. Moreover, the lithium precipitation mother liquor, the soda solution, and the refined liquid are all electrolyte solutions and have certain electrochemical corrosiveness. Therefore, the internal material of the heat exchanger is preferably titanium alloy, and zinc blocks are installed on the metal surface to reduce electrochemical corrosion by the method of sacrificial anode protection.

[0040] Moreover, in this embodiment, thermometers and pressure gauges are installed inside and at the outlets of all the tanks, and thermometers and pressure gauges are installed on the pipelines of the four inlet and outlet interfaces of all the heat exchangers. The heat exchange temperature can be adjusted according to the temperature, pressure, and flow rate, thereby controlling the entire heat exchange network.

[0041] A process for the efficient comprehensive utilization of the waste heat of the lithium precipitation mother liquor is a process for the efficient comprehensive utilization of waste heat realized by using the device for the efficient comprehensive utilization of the waste heat of the lithium precipitation mother liquor as described above, and includes the following steps:

[0042] Step 1: The lithium precipitation mother liquor generated by the battery-grade lithium carbonate production process enters the parallel high-purity water heat exchanger 1 3 and high-purity water heat exchanger 2 4 and the parallel soda solution heat exchanger 2 6 and soda solution heat exchanger 1 7 respectively through the high-temperature lithium precipitation mother liquor storage tank 1.

[0043] Specifically, the lithium precipitation mother liquor serves as a heat source, with a temperature of 70 °C and a total feed flow rate of 150 m 3 / h, and the inlet and outlet flows are the same. The lithium precipitation mother liquor leaving the high-temperature lithium precipitation mother liquor storage tank 1 is divided into two streams. One stream enters the high-purity water heat exchanger, with a total flow rate of 120 m 3 / h, and the other stream enters the soda solution heat exchanger, with a total flow rate of 30 m 3 / h, to achieve the first-stage waste heat utilization of the lithium precipitation mother liquor. Two high-purity water heat exchangers and two soda ash solution heat exchangers are in parallel, and the flow rates are evenly distributed. Specifically, the flow rates of high-purity water heat exchanger 1-3 and high-purity water heat exchanger 2-4 are both 60 m 3 / h, and the flow rates of soda ash solution heat exchanger 2-6 and soda ash solution heat exchanger 1-7 are both 15 m 3 / h. To meet the heat exchange requirements, different pipe sizes are configured in this embodiment. Coupled with changing the pump frequency and regulating valve opening, the pressure of the lithium precipitation mother liquor entering the heat exchanger remains at about 0.45 MPa.

[0044] Step 2: High-purity water enters high-purity water heat exchanger 1-3 through the low-temperature high-purity water tank 9 to achieve the first-stage heat exchange, and then enters high-purity water heat exchanger 2-4 to achieve the second-stage heat exchange. The heated high-purity water is transported to the high-temperature high-purity water tank 10. Soda ash solution enters soda ash solution heat exchanger 2-6 through the low-temperature soda ash solution storage tank 12 to achieve the first-stage heat exchange, and then enters soda ash solution heat exchanger 1-7 to achieve the second-stage heat exchange. The heated soda ash solution is transported to the high-temperature soda ash solution storage tank 13.

[0045] Specifically, during the first-stage waste heat utilization of the lithium precipitation mother liquor, the high-purity water in the first heat exchange system serves as the cold source, with a temperature of 20 °C and a flow rate of 40 m 3 / h. The pressure entering high-purity water heat exchanger 1-3 is about 0.5 MPa. Both the first-stage and second-stage heat exchanges of high-purity water are in countercurrent mode. The heated high-purity water is transported to the high-temperature high-purity water tank 10. The soda ash solution in the second heat exchange system serves as the cold source, with a temperature of 40 °C and a flow rate of 15 m 3 / h. The pressure entering soda ash solution heat exchanger 2-6 is about 0.2 MPa. Both the first-stage and second-stage heat exchanges of soda ash solution are in countercurrent mode. The heated soda ash solution is transported to the high-temperature soda ash solution storage tank 13.

[0046] Step 3: After the lithium precipitation mother liquor is heat-exchanged by the parallel high-purity water heat exchanger 1-3 and high-purity water heat exchanger 2-4, it enters the washing water heat exchanger 5 to exchange heat with the washing water from the washing water tank 11. After the lithium precipitation mother liquor is heat-exchanged by the parallel soda ash solution heat exchanger 2-6 and soda ash solution heat exchanger 1-7, it enters the refined liquid heat exchanger 8 to exchange heat with the refined liquid from the low-temperature refined liquid storage tank 14 and then enters the high-temperature refined liquid storage tank 15.

[0047] Specifically, the washing water heat exchange and the refined liquid heat exchange are the second-stage waste heat utilization of the lithium precipitation mother liquor. In this embodiment, the washing water is the heat source to be heated, with a temperature of 20 °C and a flow rate of 250 m 3 / h. The pipe flow pressure is 0.6 MPa. The preheated washing water is used for the washing process of adsorption. The refined liquid is the heat source to be heated, with a temperature of 30 °C and a flow rate of 25 m 3 / h. The pipe flow pressure is 0.35 MPa. The heated refined liquid is transported to the high-temperature refined liquid storage tank 15.

[0048] Step 4: The high-temperature pure water tank 10, the high-temperature sodium carbonate solution storage tank 13, and the high-temperature refined liquid storage tank 15 are all connected to steam through a pipeline mixer. The lithium precipitation mother liquor is heat-exchanged by the water washing water heat exchanger 5 and the refined liquid heat exchanger 8 and then transported to the low-temperature lithium precipitation mother liquor storage tank 2 for extraction use.

[0049] Specifically, steam pipeline mixers are connected to the inlet pipelines of the high-temperature pure water tank 10, the high-temperature sodium carbonate solution storage tank 13, and the high-temperature refined liquid storage tank 15, and steam regulating valves and thermometers are configured to adjust the mixing temperature to be greater than 80°C. In this embodiment, the heated pure water is used as a process medium in the alkali preparation and washing processes during the production of battery-grade lithium carbonate, and the heated sodium carbonate solution and refined liquid are used as process raw materials in the production of battery-grade lithium carbonate.

[0050] The selection of heat exchangers greatly affects the heat exchange efficiency of the heat exchange network. To achieve the maximum heat utilization efficiency, in this embodiment, the heat exchange area of the heat exchangers for the efficient comprehensive utilization of the waste heat of the lithium precipitation mother liquor is limited. Specifically: the heat exchange area of the first high-purity water heat exchanger 3 and the second high-purity water heat exchanger 4 is 80 square meters, the heat exchange area of the water washing water heat exchanger 5 is 180 square meters, the heat exchange area of the second sodium carbonate solution heat exchanger 6 and the first sodium carbonate solution heat exchanger 7 is 20 square meters, and the heat exchange area of the refined liquid heat exchanger 8 is 180 square meters.

[0051] According to the above device and process for the efficient comprehensive utilization of the waste heat of the lithium precipitation mother liquor in this embodiment, the effective cooling of the lithium precipitation mother liquor and the effective heating of the process medium and process materials can be achieved. Specifically, the high-purity water is heated from 20°C to 63.2°C, the sodium carbonate solution is heated from 40°C to 68.9°C, the water washing water is heated from 20°C to 28.8°C, the refined liquid is heated from 30°C to 60.7°C. The lithium precipitation mother liquor of the first heat exchange system is cooled from 70°C to 31°C, and the lithium precipitation mother liquor of the second heat exchange system is cooled from 70°C to 38.8°C.

[0052] In view of the above embodiments and data results, the present invention provides a device and process for the efficient comprehensive utilization of the waste heat of the lithium precipitation mother liquor, which has the advantages of being able to efficiently utilize the waste heat of the lithium precipitation mother liquor to preheat various process media and process raw materials, greatly reducing the use of steam in the production process of battery-grade lithium carbonate, achieving the efficient cooling of the pre-treatment of the lithium precipitation mother liquor extraction process. The present invention can reduce the consumption of public works, reduce the production cost of battery-grade lithium carbonate, and increase economic benefits.

[0053] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0054] The embodiments described above are only for describing the preferred embodiments of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A device for efficient and comprehensive utilization of waste heat from lithium precipitation mother liquor, characterized in that: The invention comprises a high-temperature lithium precipitation mother liquid storage tank (1), wherein the outlet end of the high-temperature lithium precipitation mother liquid storage tank (1) is connected in parallel with a high-purity water heat exchange structure and a soda ash heat exchange structure; the high-purity water heat exchange structure is connected with a water washing heat exchange structure; the soda ash heat exchange structure is connected with a refined liquid heat exchange structure, and the liquid in the high-temperature lithium precipitation mother liquid storage tank (1) is sent to a low-temperature lithium precipitation mother liquid storage tank (2) after heat exchange.

2. The device for efficient and comprehensive utilization of waste heat of lithium precipitation mother solution according to claim 1 is characterized in that: The high-purity water heat exchange structure comprises a high-purity water heat exchanger 1 (3) and a high-purity water heat exchanger 2 (4). The refrigerant inlet of the high-purity water heat exchanger 1 (3) is connected to a low-temperature high-purity water tank (9). The refrigerant inlet end of the high-purity water heat exchanger 2 (4) is connected in series to the refrigerant outlet end of the high-purity water heat exchanger 1 (3). The liquid outlet of the high-temperature lithium precipitation mother liquid storage tank (1) is connected in parallel to the heat medium inlet of the high-purity water heat exchanger 1 (3) and the heat medium inlet of the high-purity water heat exchanger 2 (4).

3. The device for efficient comprehensive utilization of waste heat of lithium precipitation mother solution according to claim 2 is characterized in that: The soda ash heat exchange structure comprises a soda ash liquid heat exchanger 2 (6) and a soda ash liquid heat exchanger 1 (7); the refrigerant inlet of the soda ash liquid heat exchanger 1 (7) is connected to a low-temperature soda ash liquid storage tank (12); the refrigerant inlet end of the soda ash liquid heat exchanger 2 (6) is connected in series to the refrigerant pipeline outlet end of the soda ash liquid heat exchanger 1 (7); and the liquid outlet of the high-temperature lithium precipitation mother liquor storage tank (1) is connected in parallel to the heat medium inlet of the soda ash liquid heat exchanger 2 (6) and the heat medium inlet of the soda ash liquid heat exchanger 1 (7), respectively.

4. The device for efficient comprehensive utilization of waste heat of lithium precipitation mother solution according to claim 2, characterized in that: The water washing heat exchange structure comprises a water washing heat exchanger (5), the heat medium inlet of the water washing heat exchanger (5) being respectively connected in parallel with the heat medium outlet of the high-purity water heat exchanger 1 (3) and the heat medium outlet of the high-purity water heat exchanger 2 (4), and the cooling medium inlet of the water washing heat exchanger (5) being connected with a water washing tank (11).

5. The device for efficient and comprehensive utilization of waste heat of lithium precipitation mother solution according to claim 3 is characterized in that: The refined liquid heat exchange structure comprises a refined liquid heat exchanger (8), the heat medium inlet of the refined liquid heat exchanger (8) being connected in parallel with the heat medium outlet of the second pure ash liquid heat exchanger (6) and the heat medium outlet of the first pure ash liquid heat exchanger (7), respectively, and the refrigerant inlet of the refined liquid heat exchanger (8) being connected with a low-temperature refined liquid storage tank (14).

6. The device for efficient comprehensive utilization of waste heat of lithium precipitation mother solution according to claim 2, characterized in that: The refrigerant outlet of the second high-purity water heat exchanger (4) is connected to a high-temperature high-purity water tank (10).

7. The device for efficient comprehensive utilization of waste heat of lithium precipitation mother solution according to claim 6, characterized in that: The refrigerant outlet of the second pure ash liquid heat exchanger (6) is connected to a high-temperature pure ash liquid storage tank (13).

8. The device for efficient comprehensive utilization of waste heat of lithium precipitation mother solution according to claim 5, characterized in that: The refrigerant outlet of the refined liquid heat exchanger (8) is connected to a high-temperature refined liquid storage tank (15).

Images