Device for recovering and separating potassium and sodium salts generated in ore lithium extraction process

Abstract

The utility model discloses a device for recovering and separating potassium and sodium salts generated in the process of extracting lithium from ore, which is characterized in that an outlet of a salt dissolving tank is connected with a freezing buffer tank, an outlet of the freezing buffer tank is connected with a freezing crystallizer, a freezing crystal slurry outlet is connected with a freezing thickener, and an outlet of the freezing thickener is connected with a freezing centrifuge; a refrigerated centrifugal solid phase outlet is connected with a hot melting tank, a bottom outlet of the hot melting tank is connected with an anhydrous sodium sulphate crystallizer, an anhydrous sodium sulphate crystal slurry outlet is connected with an anhydrous sodium sulphate thickener and an anhydrous sodium sulphate centrifuge, and a centrifugal solid phase outlet is connected with an anhydrous sodium sulphate discharge pipe; the centrifugal liquid phase outlet is connected with an anhydrous sodium sulphate mother liquor tank; a liquid phase outlet of the freezing centrifuge is connected with a freezing mother liquor tank, freezing mother liquor flows back and enters the potassium sulfate crystallizer, a potassium sulfate crystallization magma outlet is connected with the potassium sulfate thickener and the potassium sulfate centrifuge, and a potassium sulfate centrifugal solid phase outlet is connected with a potassium sulfate salt discharge pipe. The device can be used for separating the mixed salt into sodium sulfate with extremely high purity and potassium sulfate with relatively high purity, so that the product yield is improved.

Description

Technical Field

[0001] The utility model relates to a potassium and sodium salt recovery and separation device, in particular to a potassium and sodium salt recovery and separation device produced in a lithium extraction process from an ore, and belongs to the technical field of comprehensive resource utilization. Background Art

[0002] The lithium battery industry has grown rapidly in recent years, with potassium-containing lithium ores such as lepidolite and feldspar becoming key raw materials for lithium mining companies. However, in lithium extraction lines using lepidolite as raw material, high impurity levels in the material can produce large amounts of mixed salts of sodium sulfate and potassium sulfate. This salt is primarily composed of sodium sulfate and potassium sulfate, with a small amount of lithium sulfate also present.

[0003] The industry typically returns this to the front-end roasting process. This method results in some potassium sulfate being lost with the slag, resulting in wasted by-products. Potassium sulfate also accumulates throughout the system, affecting the purity of the final lithium carbonate product. This, over time, can compromise product quality. Some manufacturers choose to add purchased pure sodium sulfate to the front-end roasting process, and the resulting potassium-sodium mixed salt is sold externally. However, the low potassium concentration (30-50%) in this mixed salt makes it difficult to sell, and the lithium sulfate it contains cannot be recycled, reducing product yield. Utility Model Content

[0004] The purpose of this section is to summarize some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract and utility model title of this application, and such simplifications or omissions shall not be used to limit the scope of the present invention.

[0005] In view of the above problems and / or the problems existing in the prior art, the present utility model is proposed.

[0006] The purpose of the utility model is to overcome the problems existing in the prior art and provide a potassium and sodium salt recovery and separation device produced in the ore lithium extraction process, which can separate the mixed salt into extremely high-purity sodium sulfate and relatively pure potassium sulfate, and enrich and recover the lithium sulfate contained in the mixed salt, thereby improving the product yield.

[0007] In order to solve the above technical problems, the utility model provides a potassium and sodium salt recovery and separation device produced in a lithium extraction process from an ore, comprising a salt dissolving tank, wherein the outlet of the salt dissolving tank is connected to the inlet of a freezing buffer tank through a salt dissolving pump, the outlet of the freezing buffer tank is connected to the feed port of a freezing crystallizer through a freezing feed pump, the slurry outlet of the freezing crystallizer is connected to the inlet of a freezing thickener through a freezing slurry pump, the bottom outlet of the freezing thickener is connected to the inlet of a refrigerated centrifuge, the solid phase outlet of the refrigerated centrifuge is connected to the inlet of a hot dissolving tank, the bottom outlet of the hot dissolving tank is connected to the salt leg inlet of a sulphur dioxide crystallizer through a hot dissolving discharge pump, the salt leg slurry outlet of the sulphur dioxide crystallizer is connected to the inlet of a sulphur dioxide thickener through a sulphur dioxide slurry pump, the bottom outlet of the sulphur dioxide thickener is connected to the inlet of a sulphur dioxide centrifuge, and the solid phase outlet of the sulphur dioxide centrifuge is connected to a sulphur dioxide external discharge pipe;

[0008] The liquid phase outlet of the sodium sulphate centrifuge is connected to the inlet of the sodium sulphate mother liquor tank, and the bottom outlet of the sodium sulphate mother liquor tank is connected to the inlet pipe of the sodium sulphate circulation pump through the sodium sulphate mother liquor pump;

[0009] The liquid phase outlet of the refrigerated centrifuge is connected to the inlet of the frozen mother liquor tank, the bottom outlet of the frozen mother liquor tank is connected to the reflux port of the frozen crystallizer and the feed port of the potassium sulfate crystallizer through a frozen mother liquor pump, the salt leg slurry outlet of the potassium sulfate crystallizer is connected to the inlet of the potassium sulfate thickener through a potassium sulfate slurry pump, the bottom outlet of the potassium sulfate thickener is connected to the inlet of the potassium sulfate centrifuge, and the solid phase outlet of the potassium sulfate centrifuge is connected to the potassium sulfate salt external discharge pipe.

[0010] As an improvement of the present invention, the liquid phase outlet of the potassium sulfate centrifuge is connected to the inlet of the potassium sulfate mother liquor tank, the bottom outlet of the potassium sulfate mother liquor tank is connected to the inlet of the potassium sulfate mother liquor pump, and the outlet of the potassium sulfate mother liquor pump is connected to the inlet pipe of the potassium sulfate circulation pump and the potassium sulfate mother liquor discharge pipe through the potassium sulfate mother liquor reflux pipe.

[0011] As a further improvement of the present invention, the circulation outlet of the dissolved salt tank is connected to the inlet of the dissolved salt circulation pump, the outlet of the dissolved salt circulation pump is connected to the pipe side inlet of the dissolved salt heater, and the pipe side outlet of the dissolved salt heater is connected to the circulation inlet of the dissolved salt tank.

[0012] As a further improvement of the present invention, the circulating liquid outlet of the freezing crystallizer is connected to the inlet of the freezing circulation pump, the outlet of the freezing circulation pump is connected to the pipe side inlet of the freezing heat exchanger, and the pipe side outlet of the freezing heat exchanger is connected to the circulating liquid inlet of the freezing crystallizer.

[0013] As a further improvement of the present invention, the circulating liquid outlet of the hot melt tank is connected to the inlet of the hot melt circulation pump, the outlet of the hot melt circulation pump is connected to the pipe side inlet of the hot melt heater, and the pipe side outlet of the hot melt heater is connected to the circulating liquid inlet of the hot melt tank through a pipeline.

[0014] As a further improvement of the present invention, the circulating liquid outlet of the sulphur dioxide crystallizer is connected to the inlet of the sulphur dioxide circulation pump, the outlet of the sulphur dioxide circulation pump is connected to the tube side inlet of the sulphur dioxide evaporator, and the tube side outlet of the sulphur dioxide evaporator is connected to the circulating liquid inlet of the sulphur dioxide crystallizer.

[0015] As a further improvement of the present invention, the circulating liquid outlet of the potassium sulfate crystallizer is connected to the inlet of the potassium sulfate circulating pump, the outlet of the potassium sulfate circulating pump is connected to the tube side inlet of the potassium sulfate evaporator, and the tube side outlet of the potassium sulfate evaporator and the outlet of the refrigerated centrifugal mother liquor effluent pipe are jointly connected to the feed port of the potassium sulfate crystallizer.

[0016] As a further improvement of the present invention, the secondary steam outlet of the alum salt crystallizer is connected to the inlet of the alum salt unit compressor, and the outlet pipe of the alum salt unit compressor is connected to the shell-side steam inlet of the alum salt evaporator; the shell-side condensate outlet of the alum salt evaporator is connected to the inlet of the alum salt condensate tank, and the outlet of the alum salt condensate tank is connected to the water inlet of the salt dissolving tank through the alum salt condensate pump and the condensate reflux pipe.

[0017] As a further improvement of the present invention, the secondary steam outlet of the potassium sulfate crystallizer is connected to the inlet of the potassium sulfate unit compressor, the outlet pipe of the potassium sulfate unit compressor is connected to the shell-side steam inlet of the potassium sulfate evaporator, the shell-side condensed water outlet of the potassium sulfate evaporator is connected to the inlet of the potassium sulfate condensed water tank, and the outlet of the potassium sulfate condensed water tank is connected to the water inlet of the salt dissolving tank through a potassium sulfate condensed water pump and a condensed water reflux pipe.

[0018] Compared with the existing technology, the utility model has achieved the following beneficial effects: 1. The device recovers industrial anhydrous sodium sulfate by freezing crystallization and evaporation crystallization, and can obtain sodium sulfate products that meet the "GB / T6009-2014" Class I first-class product standards and higher-purity potassium sulfate for sale, which has great economic benefits;

[0019] 2. During the mixed salt treatment process, the lithium sulfate in the salt will be enriched in the system. After it is enriched to a certain concentration, it will be uniformly transported to the decarbonized liquid tank for lithium extraction from ore for recycling and utilization to improve the product yield.

[0020] 3. During the operation of this device, waste heat is fully recovered many times, which effectively reduces energy consumption; and no waste water or waste gas is generated during the operation, which is energy-saving and environmentally friendly and has high environmental value. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work. The drawings are only provided for reference and explanation, and are not intended to limit the present invention. Among them:

[0022] Figure 1 This is a flow chart of the potassium and sodium salt recovery and separation device produced in the lithium extraction process of ore in the utility model;

[0023] In the figure: 1. Salt dissolving tank; 2. Salt dissolving heater; 3. Salt dissolving condensate tank; 4. Refrigerated buffer tank; 5. Refrigerated crystallizer; 6. Refrigerated heat exchanger; 7. Refrigerated thickener; 8. Refrigerated centrifuge; 9. Refrigerated mother liquor tank; 10. Hot melt tank; 11. Hot melt condensate tank; 12. Hot melt heater; 13. Sodium sulfate crystallizer; 14. Sodium sulfate evaporator; 15. Sodium sulfate condensate tank; 16. Sodium sulfate mother liquor tank; 17. Sodium sulfate centrifuge; 18. Sodium sulfate thickener; 19. Sodium sulfate unit liquid storage tank; 20. Sodium sulfate unit compressor; 21. Potassium sulfate condensate tank; 22. Potassium sulfate evaporator; 23. Potassium sulfate crystallizer; 24. Potassium sulfate mother liquor tank; 25. Potassium sulfate centrifuge; 26. Potassium sulfate thickener; 27. Potassium sulfate unit liquid storage tank; 28. Potassium sulfate unit compressor.

[0024] B1. Molten salt circulation pump; B2. Molten salt condensate pump; B3. Molten salt discharge pump; B4. Chilled feed pump; B5. Chilled slurry pump; B6. Chilled circulation pump; B7. Chilled mother liquor pump; B8. Hot melt discharge pump; B9. Hot melt circulation pump; B10. Hot melt condensate pump; B11. Sodium sulfate condensate pump; B12. Sodium sulfate circulation pump; B14. Sodium sulfate slurry pump; B15. Sodium sulfate unit effluent pump; B16. Potassium sulfate condensate pump; B17. Potassium sulfate circulation pump; B18. Potassium sulfate unit effluent pump; B19. Potassium sulfate slurry pump; B20. Potassium sulfate mother liquor pump;

[0025] G1. Dissolved salt inlet chute; G2. Dissolved salt heater condensate pipe; G3. Refrigerated discharge pipe; G4. Sodium sulfate discharge chute; G5. Refrigerated centrifuge mother liquor reflux pipe; G6. Refrigerated centrifuge mother liquor effluent pipe; G7. Hot melt condensate pipe; G8. Hot solution effluent pipe; G9. Sodium sulfate effluent pipe; G10. Sodium sulfate solution effluent pipe; G11. Sodium sulfate solution reflux pipe; G12. Sodium sulfate evaporation unit non-condensable steam discharge pipe; G13. Potassium sulfate salt effluent pipe; G14. Potassium sulfate mother liquor effluent pipe; G15. Potassium sulfate mother liquor reflux pipe; G16. Potassium sulfate evaporation unit non-condensable steam discharge pipe. DETAILED DESCRIPTION

[0026] In the following description of the present invention, the terms "upper", "lower", "front", "back", "left", "right", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not mean that the device must have a specific direction.

[0027] In order to make the technical means, creative features, objectives and effects of the present invention easier to understand, the present invention is further described below with reference to specific figures. Obviously, the embodiments described are only a part of the present invention, not all of the embodiments.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in the art of the present invention. The terms used herein 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] like Figure 1 As shown, the potassium and sodium salt recovery and separation device produced in the ore lithium extraction process of the present invention includes a salt dissolving tank 1, a salt dissolving heater, a salt dissolving condensate water tank 3, a freezing buffer tank 4, a freezing crystallizer 5, a freezing heat exchanger 6, a freezing thickener 7, a freezing centrifuge 8, a freezing mother liquor tank 9, a hot dissolving tank 10, a hot dissolving condensate water tank 11, a hot dissolving heater 12, a sulphur dioxide crystallizer 13, a sulphur dioxide evaporator 14, a sulphur dioxide condensate water tank 15, a sulphur dioxide mother liquor tank 16, a sulphur dioxide centrifuge 17, a sulphur dioxide thickener 18, a sulphur dioxide unit liquid storage tank 19, a sulphur dioxide unit compressor 20, a potassium sulfate condensate water tank 21, a potassium sulfate evaporator 22, a potassium sulfate crystallizer 23, a potassium sulfate mother liquor tank 24, a potassium sulfate centrifuge 25, a potassium sulfate thickener 26, a potassium sulfate unit liquid storage tank 27 and a potassium sulfate unit compressor 28.

[0030] The outlet of the dissolved salt inlet chute G1 is connected to the feed port of the dissolved salt tank 1. The circulation outlet of the dissolved salt tank 1 is connected to the inlet of the dissolved salt circulation pump B1. The outlet of the dissolved salt circulation pump B1 is connected to the tube-side inlet of the dissolved salt heater. The tube-side outlet of the dissolved salt heater is connected to the circulation inlet of the dissolved salt tank 1. The shell side of the dissolved salt heater uses steam as the heat source. The condensed water discharged from the shell side enters the dissolved salt condensate tank 3 through the dissolved salt heater condensate pipe G2 and is collected and sent out for recycling by the dissolved salt condensate pump B2.

[0031] The discharge outlet of the dissolved salt tank 1 is connected to the inlet of the dissolved salt discharge pump B3, the outlet of the dissolved salt discharge pump B3 is connected to the inlet of the frozen buffer tank 4, the outlet of the frozen buffer tank 4 is connected to the inlet of the frozen feed pump B4, the outlet of the frozen feed pump B4 is connected to the feed port of the frozen crystallizer 5, the circulating liquid outlet of the frozen crystallizer 5 is connected to the inlet of the frozen circulation pump B6, the outlet of the frozen circulation pump B6 is connected to the pipe-side inlet of the frozen heat exchanger 6, and the pipe-side outlet of the frozen heat exchanger 6 is connected to the circulating liquid inlet of the frozen crystallizer 5. The slurry outlet of the frozen crystallizer 5 is connected to the inlet of the frozen slurry pump B5, the outlet of the frozen slurry pump B5 is connected to the inlet of the frozen thickener 7 through the frozen discharge pipe G3, the bottom outlet of the frozen thickener 7 is connected to the inlet of the refrigerated centrifuge 8, and the solid phase outlet of the refrigerated centrifuge 8 is connected to the inlet of the hot melt tank 10 through the mirabilite discharge chute G4.

[0032] The circulating liquid outlet of the hot melt tank 10 is connected to the inlet of the hot melt circulation pump B9, the outlet of the hot melt circulation pump B9 is connected to the tube-side inlet of the hot melt heater 12, and the tube-side outlet of the hot melt heater 12 is connected to the circulating liquid inlet of the hot melt tank 10 via a pipeline. The bottom outlet of the hot melt tank 10 is connected to the inlet of the hot melt discharge pump B8, the outlet of the hot melt discharge pump B8 is connected to the salt leg inlet of the sulphur dioxide crystallizer 13 via the hot solution external discharge pipe G8, the circulating liquid outlet of the sulphur dioxide crystallizer 13 is connected to the inlet of the sulphur dioxide circulation pump B12, the outlet of the sulphur dioxide circulation pump B12 is connected to the tube-side inlet of the sulphur dioxide evaporator 14, and the tube-side outlet of the sulphur dioxide evaporator 14 is connected to the circulating liquid inlet of the sulphur dioxide crystallizer 13.

[0033] The salt leg slurry outlet of the alum crystallizer 13 is connected to the inlet of the alum slurry slurry pump B14, the outlet of the alum slurry pump B14 is connected to the inlet of the alum thickener 18, the bottom outlet of the alum thickener 18 is connected to the inlet of the alum centrifuge 17, and the solid phase outlet of the alum centrifuge 17 is connected to the alum discharge pipe G9.

[0034] The liquid phase outlet of the sodium sulfate centrifuge 17 is connected to the inlet of the sodium sulfate mother liquor tank 16. The overflow outlet of the sodium sulfate thickener 18 is connected to the inlet of the sodium sulfate mother liquor tank 16 via an overflow pipe. The bottom outlet of the sodium sulfate mother liquor tank 16 is connected to the inlet of the sodium sulfate mother liquor pump B13. The outlet of the sodium sulfate mother liquor pump B13 is connected to the inlet pipe of the sodium sulfate circulation pump B12 via the sodium sulfate solution reflux pipe G11. The outlet of the sodium sulfate mother liquor pump B13 is also connected to the sodium sulfate solution discharge pipe G10.

[0035] The liquid phase outlet of the refrigerated centrifuge 8 and the overflow port of the refrigerated thickener 7 are connected to the inlet of the refrigerated mother liquor tank 9, the bottom outlet of the refrigerated mother liquor tank 9 is connected to the inlet of the refrigerated mother liquor pump B7, the outlet of the refrigerated mother liquor pump B7 is connected to the refrigerated centrifuge mother liquor reflux pipe G5 and the refrigerated centrifuge mother liquor external discharge pipe G6, and the refrigerated centrifuge mother liquor reflux pipe G5 is connected to the reflux port of the refrigerated crystallizer 5.

[0036] The outlet of the refrigerated centrifugal mother liquor effluent pipe G6 is connected to the feed port of the potassium sulfate crystallizer 23, the circulating liquid outlet of the potassium sulfate crystallizer 23 is connected to the inlet of the potassium sulfate circulation pump B17, the outlet of the potassium sulfate circulation pump B17 is connected to the tube side inlet of the potassium sulfate evaporator 22, and the tube side outlet of the potassium sulfate evaporator 22 and the outlet of the refrigerated centrifugal mother liquor effluent pipe G6 are jointly connected to the feed port of the potassium sulfate crystallizer 23.

[0037] The salt leg slurry outlet of the potassium sulfate crystallizer 23 is connected to the inlet of the potassium sulfate slurry pump B19, the outlet of the potassium sulfate slurry pump B19 is connected to the inlet of the potassium sulfate thickener 26, the bottom outlet of the potassium sulfate thickener 26 is connected to the inlet of the potassium sulfate centrifuge 25, and the solid phase outlet of the potassium sulfate centrifuge 25 is connected to the potassium sulfate salt effluent pipe G13.

[0038] The liquid phase outlet of the potassium sulfate centrifuge 25 is connected to the inlet of the potassium sulfate mother liquor tank 24, the overflow port of the potassium sulfate thickener 26 is also connected to the inlet of the potassium sulfate mother liquor tank 24 through an overflow pipe, the bottom outlet of the potassium sulfate mother liquor tank 24 is connected to the inlet of the potassium sulfate mother liquor pump B20, and the outlet of the potassium sulfate mother liquor pump B20 is connected to the inlet pipeline of the potassium sulfate circulation pump B17 through the potassium sulfate mother liquor reflux pipe G15; the outlet of the potassium sulfate mother liquor pump B20 is also connected to the potassium sulfate mother liquor effluent pipe G14.

[0039] The shell side of the hot melt heater 12 is heated by raw steam. The shell side condensate outlet of the hot melt heater 12 is connected to the hot melt condensate tank 11 through the hot melt condensate pipe G7. The outlet of the hot melt condensate tank 11 is connected to the inlet of the hot melt condensate pump B10. The outlet of the hot melt condensate pump B10 is connected to the condensate reuse system.

[0040] The secondary steam outlet of the alum crystallizer 13 is connected to the inlet of the alum unit compressor 20, the outlet pipe of the alum unit compressor 20 is connected to the shell-side steam inlet of the alum evaporator 14, the condensed water precipitated from the inlet pipe of the alum unit compressor 20 enters the alum unit liquid storage tank 19 for collection, the volute condensed water outlet of the alum unit compressor 20 is also connected to the alum unit liquid storage tank 19, and the bottom outlet of the alum unit liquid storage tank 19 is connected to the condensed water reuse system through the alum unit liquid storage pump B15.

[0041] The shell-side condensate outlet of sodium sulfate evaporator 14 is connected to the inlet of sodium sulfate condensate tank 15. The outlet of sodium sulfate condensate tank 15 is connected to the inlet of sodium sulfate condensate pump B11. The outlet of sodium sulfate condensate pump B11 is connected to the water inlet of salt dissolving tank 1 via a condensate return pipe. The shell-side of sodium sulfate evaporator 14 is also connected to the vacuum system via the sodium sulfate evaporation unit non-condensable steam discharge pipe G12.

[0042] The secondary steam outlet of the potassium sulfate crystallizer 23 is connected to the inlet of the potassium sulfate unit compressor 28, the outlet pipe of the potassium sulfate unit compressor 28 is connected to the shell-side steam inlet of the potassium sulfate evaporator 22, and the condensed water precipitated from the inlet pipe of the potassium sulfate unit compressor 28 enters the potassium sulfate unit liquid accumulation tank 27 for collection. The volute condensed water outlet of the potassium sulfate unit compressor 28 is also connected to the potassium sulfate unit liquid accumulation tank 27, and the bottom outlet of the potassium sulfate unit liquid accumulation tank 27 is connected to the condensed water reuse system through the potassium sulfate unit liquid accumulation pump B18.

[0043] The shell-side condensate outlet of potassium sulfate evaporator 22 is connected to the inlet of potassium sulfate condensate tank 21, which is in turn connected to the inlet of potassium sulfate condensate pump B16. The outlet of potassium sulfate condensate pump B16 is connected to the water inlet of salt dissolving tank 1 via a condensate return pipe. The shell-side of potassium sulfate evaporator 22 is also connected to the vacuum system via potassium sulfate evaporation unit non-condensable steam discharge pipe G16.

[0044] The mixed salt enters the salt dissolving tank 1 through the salt dissolving inlet pipe G1, where it is mixed and dissolved with water at a rate of 1.75 to 2 times the salt content, dissolving at a temperature of 40 to 50°C. This solution is then circulated and heated by the salt dissolving circulation pump B1. After heating, the material is fed to the freezing buffer tank 4 via the salt dissolving discharge pump B3, and then enters the freezing crystallizer 5 via the freezing feed pump B4. The material in the freezing crystallizer 5 is cooled to 15 to 20°C by the freezing heat exchanger 6 and the freezing circulation pump B6, precipitating the saltcake. The material containing saltcake is then passed through the freezing slurry pump B5 and the freezing discharge pipe G3 to the freezing thickener 7 for sedimentation. The settled material enters the refrigerated centrifuge 8 for solid-liquid separation. After the salt-freezing mother liquor enters the freezing mother liquor tank 9, a portion of it is returned to the freezing crystallizer 5 via the freezing centrifuge mother liquor reflux pipe G5, and a portion of it is passed through the freezing centrifuge mother liquor effluent pipe G6 to enter the potassium sulfate crystallizer 23.

[0045] The centrifuged sodium sulfate has a purity greater than 98.6% by weight. It enters the hot melt tank 10 through the sodium sulfate discharge chute G4, where it mixes with water to form a sodium sulfate solution. This solution is heated to 70-80°C by the hot melt heater 12 and then fed to the glauber salt crystallizer 13 via the hot melt discharge pump B8 and the hot solution discharge pipe G8. Within the system, the sodium sulfate solution is heated and evaporated in the glauber salt evaporator 14 to precipitate sodium sulfate. The sodium sulfate-containing material is then fed by the glauber salt slurry pump B14 to the glauber salt thickener 18 for sedimentation. The settled material then enters the glauber salt centrifuge 17, where sodium sulfate is centrifuged and discharged through the glauber salt discharge pipe G9. The dried sodium sulfate product meets the Class I, first-grade standard for industrial anhydrous sodium sulfate (GB / T6009-2014).

[0046] The centrifuged mother liquor from the sodium sulfate centrifuge 17 enters the sodium sulfate mother liquor tank 16 for temporary storage, and is then sent out by the sodium sulfate mother liquor pump B13 and refluxed through the sodium sulfate solution reflux pipe G11. When the lithium in the material of the evaporation crystallization system reaches a certain concentration, the centrifuged mother liquor opens the sodium sulfate solution external discharge pipe G10 to the decarbonization liquid tank at the front end of the production line to recover lithium.

[0047] The secondary steam discharged from the sodium sulfate crystallizer 13 enters the sodium sulfate unit compressor 20 for compression and temperature increase, then returns to the shell-side inlet of the sodium sulfate evaporator 14 as a heat source. The condensed water produced after heat exchange flows from the shell-side outlet of the sodium sulfate evaporator 14 into the sodium sulfate condensate tank 15 for collection. The sodium sulfate condensate pump B11 returns the condensed water to the salt dissolving tank 1 to dissolve salt, thus achieving water recycling. The condensed water in the inlet pipe of the sodium sulfate unit compressor 20 and the condensed water generated in the volute enter the sodium sulfate unit liquid storage tank 19 for collection and is then pumped out for reuse by the sodium sulfate unit liquid storage pump B15.

[0048] The potassium sulfate solution entering the potassium sulfate crystallizer 23 is sent to the potassium sulfate evaporator 22 for circulation heating through the potassium sulfate circulation pump B17. The potassium sulfate evaporator 22 heats and evaporates to precipitate potassium sulfate. The potassium sulfate slurry is sent to the potassium sulfate thickener 26 for sedimentation through the potassium sulfate slurry pump B19. The settled material enters the potassium sulfate centrifuge 25 for centrifugal separation, and the solid phase is discharged through the potassium sulfate salt external discharge pipe G13. The mass of potassium sulfate accounts for 75~85%wt, and the mass of sodium sulfate accounts for 10~15%wt.

[0049] The mother liquor separated by the potassium sulfate centrifuge 25 enters the potassium sulfate mother liquor tank 24 for temporary storage, is sent out through the potassium sulfate circulation pump B17, and is refluxed through the potassium sulfate mother liquor reflux pipe G15. When the lithium in the material of the potassium sulfate crystallizer 23 reaches a certain concentration, the mother liquor is discharged through the potassium sulfate mother liquor effluent pipe G14 to the decarbonization liquid tank at the front end of the production line to recover lithium.

[0050] The secondary steam discharged from the potassium sulfate crystallizer 23 enters the potassium sulfate unit compressor 28 for compression and temperature increase, then returns to the shell-side inlet of the potassium sulfate evaporator 22 as a heat source. The condensed water produced after heat exchange is discharged from the shell-side drain of the potassium sulfate evaporator 22 and collected in the potassium sulfate condensate tank 21. The potassium sulfate condensate pump B16 then returns the condensed water to the salt dissolving tank 1 for dissolution, thus achieving water recycling. The condensed water in the secondary steam pipe and the volute condensed water from the potassium sulfate unit compressor 28 enter the potassium sulfate unit liquid storage tank 27 for collection and recovery via the potassium sulfate unit liquid storage pump B18.

[0051] The above description is only a preferred embodiment of the present invention, which shows and describes the basic principles, main features and advantages of the present invention, but does not limit the scope of patent protection of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. In addition to the above embodiments, the present invention may have other implementation methods without departing from the spirit and scope of the present invention. The present invention may also have various changes and improvements, and all technical solutions formed by equivalent replacement or equivalent transformation fall within the scope of protection required by the present invention. The scope of protection required by the present invention is defined by the attached claims and their equivalents. Technical features not described in the present invention can be achieved by or using existing technologies, and will not be described here.

Claims

1. A device for recovering and separating potassium and sodium salts produced in a lithium extraction process from an ore, comprising a salt dissolving tank, characterized in that: The outlet of the molten salt tank is connected to the inlet of the freezing buffer tank by a molten salt discharging pump, the outlet of the freezing buffer tank is connected to the feed port of the freezing crystallizer by a freezing feed pump, the slurry outlet of the freezing crystallizer is connected to the inlet of the freezing thickener by a freezing slurry pump, the bottom outlet of the freezing thickener is connected to the inlet of the refrigerated centrifuge, the solid phase outlet of the refrigerated centrifuge is connected to the inlet of the hot melt tank, the bottom outlet of the hot melt tank is connected to the salt leg inlet of the glauber salt crystallizer by the hot melt discharging pump, the salt leg slurry outlet of the glauber salt crystallizer is connected to the inlet of the glauber salt thickener by the glauber salt slurry pump, the bottom outlet of the glauber salt thickener is connected to the inlet of the glauber salt centrifuge, and the solid phase outlet of the glauber salt centrifuge is connected to the glauber salt external discharge pipe; The liquid phase outlet of the sodium sulphate centrifuge is connected to the inlet of the sodium sulphate mother liquor tank, and the bottom outlet of the sodium sulphate mother liquor tank is connected to the inlet pipe of the sodium sulphate circulation pump through the sodium sulphate mother liquor pump; The liquid phase outlet of the refrigerated centrifuge is connected to the inlet of the frozen mother liquor tank, the bottom outlet of the frozen mother liquor tank is connected to the reflux port of the frozen crystallizer and the feed port of the potassium sulfate crystallizer through a frozen mother liquor pump, the salt leg slurry outlet of the potassium sulfate crystallizer is connected to the inlet of the potassium sulfate thickener through a potassium sulfate slurry pump, the bottom outlet of the potassium sulfate thickener is connected to the inlet of the potassium sulfate centrifuge, and the solid phase outlet of the potassium sulfate centrifuge is connected to the potassium sulfate salt external discharge pipe.

2. The potassium and sodium salt recovery and separation device produced in the ore lithium extraction process according to claim 1, characterized in that: The liquid phase outlet of the potassium sulfate centrifuge is connected to the inlet of the potassium sulfate mother liquor tank, the bottom outlet of the potassium sulfate mother liquor tank is connected to the inlet of the potassium sulfate mother liquor pump, and the outlet of the potassium sulfate mother liquor pump is connected to the inlet pipe of the potassium sulfate circulation pump and the potassium sulfate mother liquor effluent pipe through the potassium sulfate mother liquor reflux pipe.

3. The potassium and sodium salt recovery and separation device produced in the ore lithium extraction process according to claim 1, characterized in that: The circulation outlet of the dissolved salt tank is connected to the inlet of the dissolved salt circulation pump, the outlet of the dissolved salt circulation pump is connected to the pipe side inlet of the dissolved salt heater, and the pipe side outlet of the dissolved salt heater is connected to the circulation inlet of the dissolved salt tank.

4. The potassium and sodium salt recovery and separation device produced in the ore lithium extraction process according to claim 1, characterized in that: The circulating liquid outlet of the freezing crystallizer is connected to the inlet of the freezing circulation pump, the outlet of the freezing circulation pump is connected to the pipe side inlet of the freezing heat exchanger, and the pipe side outlet of the freezing heat exchanger is connected to the circulating liquid inlet of the freezing crystallizer.

5. The potassium and sodium salt recovery and separation device produced in the ore lithium extraction process according to claim 1, characterized in that: The circulating liquid outlet of the hot melt tank is connected to the inlet of the hot melt circulation pump, the outlet of the hot melt circulation pump is connected to the pipe side inlet of the hot melt heater, and the pipe side outlet of the hot melt heater is connected to the circulating liquid inlet of the hot melt tank through a pipeline.

6. The potassium and sodium salt recovery and separation device produced in the ore lithium extraction process according to claim 1, characterized in that: The circulating liquid outlet of the sulphur sulfate crystallizer is connected to the inlet of the sulphur sulfate circulation pump, the outlet of the sulphur sulfate circulation pump is connected to the tube side inlet of the sulphur sulfate evaporator, and the tube side outlet of the sulphur sulfate evaporator is connected to the circulating liquid inlet of the sulphur sulfate crystallizer.

7. The potassium and sodium salt recovery and separation device produced in the ore lithium extraction process according to claim 1, characterized in that: The circulating liquid outlet of the potassium sulfate crystallizer is connected to the inlet of the potassium sulfate circulation pump, the outlet of the potassium sulfate circulation pump is connected to the tube side inlet of the potassium sulfate evaporator, and the tube side outlet of the potassium sulfate evaporator and the outlet of the refrigerated centrifugal mother liquor effluent pipe are jointly connected to the feed port of the potassium sulfate crystallizer.

8. The device for recovering and separating potassium and sodium salts produced in the process for extracting lithium from ore according to any one of claims 1 to 7, characterized in that: The secondary steam outlet of the sulphur dioxide crystallizer is connected to the inlet of the sulphur dioxide unit compressor, and the outlet pipe of the sulphur dioxide unit compressor is connected to the shell-side steam inlet of the sulphur dioxide evaporator; the shell-side condensed water outlet of the sulphur dioxide evaporator is connected to the inlet of the sulphur dioxide condensed water tank, and the outlet of the sulphur dioxide condensed water tank is connected to the water inlet of the salt dissolving tank through the sulphur dioxide condensed water pump and the condensed water reflux pipe.

9. The device for recovering and separating potassium and sodium salts produced in the process for extracting lithium from ore according to any one of claims 1 to 7, characterized in that: The secondary steam outlet of the potassium sulfate crystallizer is connected to the inlet of the potassium sulfate unit compressor, the outlet pipe of the potassium sulfate unit compressor is connected to the shell-side steam inlet of the potassium sulfate evaporator, the shell-side condensed water outlet of the potassium sulfate evaporator is connected to the inlet of the potassium sulfate condensed water tank, and the outlet of the potassium sulfate condensed water tank is connected to the water inlet of the salt dissolving tank through a potassium sulfate condensed water pump and a condensed water reflux pipe.

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