Salt separation and recovery device for sodium chloride and potassium chloride

Abstract

The utility model relates to the technical field of potassium chloride recovery devices, in particular to a salt separation and recovery device for sodium chloride and potassium chloride. The utility model provides a sodium chloride and potassium chloride salt separation and recovery device which comprises an evaporator, an evaporative cooler, a first thickener, a first centrifugal machine, a first mother liquor tank, a first condensate water tank, a first discharging pump, a first vacuum pump and a mother liquor pump which are sequentially connected through pipelines. The evaporators are three groups of triple-effect circulating evaporators which are arranged in series and can effectively improve the concentration of sodium chloride and potassium chloride, and the system further comprises a flash separator, a flash circulating pump, a flash cooler, a second vacuum pump, a second condensate water tank, a second thickener, a second centrifugal machine, a second mother liquor tank and a second discharge pump which are sequentially connected through pipelines; the first mother liquor tank is communicated with the flash separator through a first mother liquor pump; according to the recovery device, concentration and crystallization of sodium chloride can be achieved through the triple-effect circulation evaporator, and flash evaporation and crystallization of potassium chloride can be achieved through the flash evaporation evaporator.

Description

Technical Field

[0001] This application relates to the technical field of potassium chloride recovery devices, and particularly to a salt separation and recovery device for sodium chloride and potassium chloride. Background Art

[0002] In the resource recycling production of fly ash and blast furnace bag filter ash generated by steel mills, coking plants, biomass boilers, etc., potassium elements are recovered; the ash is prepared into an inorganic salt solution through water washing, adding flocculant for precipitation, etc., which contains sodium chloride, potassium chloride and other trace impurities. After plate and frame filtration and chemical impurity removal, the pH value is adjusted back to 7-8, and the resulting neutral solution contains two substances, potassium chloride and sodium chloride.

[0003] Among them, potassium chloride is a potassium fertilizer resource required for crop growth. If potassium fertilizer containing sodium chloride is used too much for land fertilization, it will cause land salinization and soil compaction, resulting in crop yield reduction. Therefore, in industrial production, it is necessary to separate and purify it to reduce the content of sodium salts in it. Since both sodium chloride and potassium chloride are salts, it is impossible to use displacement reaction for purification. Therefore, how to effectively separate the two is particularly important. Summary of the Utility Model

[0004] The problem to be solved by this application is that the existing neutral waste liquid contains potassium chloride and sodium chloride substances with similar properties. Since both sodium chloride and potassium chloride are salts, it is impossible to use displacement reaction to separate and purify the two.

[0005] To solve the above technical problems, this application provides a salt separation and recovery device for sodium chloride and potassium chloride, which includes an evaporator, an evaporation cooler, a first thickener, a first centrifuge, a first mother liquor tank, a first condensate tank, a first discharge pump, a first vacuum pump and a mother liquor pump connected in sequence through pipelines. The evaporator is a triple-effect circulation evaporator arranged in series with three groups, which can effectively improve the concentration of sodium chloride and potassium chloride. It also includes a flash separator, a flash circulation pump, an evaporation cooler, a second vacuum pump, a second condensate tank, a second thickener, a second centrifuge, a second mother liquor tank and a second discharge pump connected in sequence through pipelines. The first mother liquor tank is connected to the flash separator through a first mother liquor pump.

[0006] Since the recovery device of this application is designed with a triple-effect circulation evaporator and a flash evaporator, it can not only achieve the concentration and crystallization of sodium chloride through the triple-effect circulation evaporator, but also achieve the flash crystallization of potassium chloride through the flash evaporator, solving the problem that the existing neutral waste liquid contains potassium chloride and sodium chloride substances with similar properties. Since both sodium chloride and potassium chloride are salts, it is impossible to use displacement reaction to separate and purify the two. Brief Description of the Drawings

[0007] Figure 1Schematic diagram of the production process flow of the embodiment.

[0008] In the figure: 1. Primary heater; 2. Secondary heater; 3. Tertiary heater; 4. Primary separator; 5. Secondary separator; 6. Tertiary separator; 7. Evaporative cooler; 8. First thickener; 9. First centrifuge; 10. First mother liquor tank; 11. First condensate water tank; 12. Primary circulation pump; 13. Secondary circulation pump; 14. Tertiary circulation pump; 15. First discharge pump; 16. First vacuum pump; 17. Mother liquor pump; 18. Flash separator; 19. Flash circulation pump; 20. Flash discharge pump; 21. Evaporative cooler; 22. Second vacuum pump; 23. Second condensate water tank; 24. Second thickener; 25. Second centrifuge; 26. Second discharge pump; 27. Second mother liquor tank. Detailed implementation manners

[0009] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application. Embodiment

[0010] The present application relates to a salt separation and recovery device for sodium chloride and potassium chloride. As Figure 1 shown, the recovery device includes an evaporator, an evaporative cooler 7, a first thickener 8, a first centrifuge 9, a first mother liquor tank 10, a first condensate water tank 11, a first discharge pump 15, a first vacuum pump 16, and a mother liquor pump 17, which are sequentially connected by pipelines. In order to effectively increase the concentration of sodium chloride and lithium chloride, therefore, the evaporator is a triple-effect circulation evaporator with three groups arranged in series that can effectively increase the concentration of sodium chloride and potassium chloride. The triple-effect circulation evaporator includes a primary evaporator, a secondary evaporator, and a tertiary evaporator, which are sequentially connected by pipelines, so as to obtain solid sodium chloride salt through the above-mentioned cyclic evaporation operation.

[0011] The primary evaporator includes a primary heater 1, a primary separator 4, and a primary circulation pump 12, which are sequentially connected by pipelines. The secondary evaporator includes a secondary heater 2, a secondary separator 5, and a secondary circulation pump 13, which are sequentially connected by pipelines. The tertiary evaporator includes a tertiary heater 3, a tertiary separator 6, and a tertiary circulation pump 14, which are sequentially connected by pipelines.

[0012] The bottom side wall of the primary heater 1 is provided with a raw material inlet, the top side wall of the primary heater 1 is provided with a steam inlet, the top output end of the primary heater 1 is connected to the side wall input end of the primary separator 4 through a pipeline, the output end of the primary circulation pump 12 is connected to the input end of the primary heater 1 through a pipeline, and the input end of the primary circulation pump 12 is connected to the bottom output end of the primary separator 4 through a pipeline. Thus, by means of the rotation of the primary circulation pump 12, the raw material is evenly pushed into the primary heater 1 from the bottom, and then the heated raw material is pushed out from the top of the primary heater 1 and then enters the primary separator 4 to complete the gas-liquid separation operation.

[0013] The arrangement forms of the secondary evaporator and the tertiary evaporator are the same as that of the primary evaporator. The gas-liquid separated by the primary evaporator is the raw material and steam of the secondary evaporator, and the gas-liquid separated by the secondary evaporator is the raw material and steam of the tertiary evaporator. Thus, after the raw material undergoes three concentration operations, a crystal slurry liquid containing precipitated sodium chloride crystals is obtained.

[0014] In order to further obtain solid potassium chloride salt, the recovery device further includes a flash separator 18, a flash circulation pump 19, a flash cooler 21, a second vacuum pump 22, a second condensate tank 23, a second thickener 24, a second centrifuge 25, a second mother liquor tank 27 and a second discharge pump 26 that are connected in sequence through pipelines. The first mother liquor tank 10 is connected to the flash separator 18 through a first mother liquor pump 17. The input end of the flash circulation pump 19 is connected to the bottom output end of the flash separator 18 through a pipeline. Thus, by means of the rotation of the flash circulation pump 19, the raw material is evenly pushed into the flash heater from the bottom, and then the heated raw material is pushed out from the top of the flash heater and then enters the flash separator 18 to complete the gas-liquid separation operation.

[0015] Then, the mother liquor in the first mother liquor tank 10 enters the flash process, potassium chloride crystals are precipitated after flash cooling, and are sent to the second centrifuge 25 by the flash discharge pump 20 to complete dehydration to obtain potassium chloride crystals; the mother liquor in the second mother liquor tank 27 is pumped into the flash separator 18 by the second discharge pump 26 for recycle of the mother liquor; continuous and stable production is achieved, and the production efficiency is improved; the purity of potassium chloride after salt separation by this device can reach 60-80%, fully meeting the industry sales standard.

[0016] Generally speaking, terms should be understood at least in part by their use in context. For example, at least in part depending on the context, the term "one or more" used in the text can be used to describe any feature, structure or property with a singular meaning, or can be used to describe a combination of features, structures or properties with a plural meaning. Similarly, at least in part depending on the context, terms such as "a" or "the" can also be understood as conveying a singular usage or conveying a plural usage.

[0017] It should be easily understood that the terms "on", "above", and "over" in this disclosure should be interpreted in the broadest manner, such that "on" not only means "directly on something", but also includes the meaning of "on something" with intermediate features or layers therebetween, and "above" or "over" not only includes the meaning of "above" or "over something", but may also include the meaning of "above" or "over something" with no intermediate features or layers therebetween (i.e., directly on something).

[0018] In addition, for ease of description, spatial relative terms may be used in the text, such as "below", "beneath", "under", "above", "over", etc., to describe the relationship of one element or feature to other elements or features as shown in the figures. Spatial relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation shown in the figures. The device may have other orientations (rotated 90 degrees or in other orientations), and the spatial relative descriptors used in the text may be interpreted accordingly as well.

[0019] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A sodium chloride and potassium chloride salt recovery device, characterized in that: The invention comprises an evaporator, an evaporative cooler, a first thickener, a first centrifuge, a first mother liquid tank, a first condensate tank, a first discharge pump, a first vacuum pump and a mother liquid pump which are connected in sequence through pipelines. The evaporator is a triple-effect circulating evaporator which is arranged in series and can effectively improve the concentration of sodium chloride and potassium chloride. The invention also comprises a flash separator, a flash circulation pump, a flash cooler, a second vacuum pump, a second condensate tank, a second thickener, a second centrifuge, a second mother liquid tank and a second discharge pump which are connected in sequence through pipelines. The first mother liquid tank is connected to the flash separator through the first mother liquid pump.

2. The salt separation and recovery device for sodium chloride and potassium chloride according to claim 1, characterized in that: The three-effect circulation evaporator includes a primary evaporator, a secondary evaporator, and a tertiary evaporator which are connected in sequence through pipelines.

3. The salt separation and recovery device for sodium chloride and potassium chloride according to claim 2, characterized in that: The primary evaporator comprises a primary heater, a primary separator and a primary circulation pump which are sequentially connected through pipelines. The bottom side wall of the primary heater is provided with a raw material inlet, and the top side wall of the primary heater is provided with a steam inlet.

4. The salt separation and recovery device for sodium chloride and potassium chloride according to claim 2, characterized in that: The secondary evaporator comprises a secondary heater, a secondary separator and a secondary circulation pump which are connected in sequence through pipelines.

5. The salt separation and recovery device for sodium chloride and potassium chloride according to claim 2, characterized in that: The three-stage evaporator includes a three-stage heater, a three-stage separator, and a three-stage circulation pump which are sequentially connected through pipelines.

6. The salt separation and recovery device for sodium chloride and potassium chloride according to claim 3, characterized in that: The top output end of the primary heater is connected to the side wall input end of the primary separator through a pipeline, the output end of the primary circulation pump is connected to the input end of the primary heater through a pipeline, and the input end of the primary circulation pump is connected to the bottom output end of the primary separator through a pipeline.

7. The salt separation and recovery device for sodium chloride and potassium chloride according to claim 2, characterized in that: The layout of the secondary evaporator, the tertiary evaporator and the primary evaporator is the same.

8. The salt separation and recovery device for sodium chloride and potassium chloride according to claim 1, characterized in that: The input end of the discharge pump is connected to the output end of the tertiary circulation pump through a pipeline, the output end of the discharge pump is connected to the input end of the thickener through a pipeline, the output end of the thickener is connected to the input end of the centrifuge through a pipeline, the output end of the centrifuge is connected to the input end of the mother liquid tank through a pipeline, the input end of the mother liquid pump is connected to the output end of the mother liquid tank through a pipeline, and the output end of the mother liquid pump is connected to the tertiary separator through a pipeline.

9. The salt separation and recovery device for sodium chloride and potassium chloride according to claim 1, characterized in that: The input end of the flash circulation pump is connected to the bottom output end of the flash separator through a pipeline.

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