Comprehensive treatment system for waste phosphoric acid

Abstract

The utility model relates to the technical field of waste liquid treatment, and particularly discloses a comprehensive treatment system for waste phosphoric acid, which comprises a waste phosphoric acid tank, an ammonia water tank, a reaction tank, a filtering device, an ion exchange device, a crystallization device, a centrifugal machine, a drying device and a concentration device, the waste phosphoric acid tank and the ammonia water tank are connected with the reaction tank, and the reaction tank is used for reacting waste phosphoric acid with ammonia water; the reaction tank, the filtering device, the ion exchange device, the crystallization device, the centrifugal machine and the drying device are connected in sequence, the filtering device is used for filtering a solution, the ion exchange device is used for removing metal ions in the solution, the crystallization device is used for crystallizing and separating out ammonium dihydrogen phosphate, and the centrifugal machine is used for centrifugally separating wet ammonium dihydrogen phosphate; the drying device is used for drying the wet ammonium dihydrogen phosphate to prepare the ammonium dihydrogen phosphate; the concentration device is respectively connected with the centrifugal machine and the crystallization device, and the concentration device is used for concentrating mother liquor and conveying the concentrated solution to the crystallization device. According to the utility model, the overall structure is simplified, and the system cost is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of waste liquid treatment, in particular to a comprehensive treatment system for waste phosphoric acid. Background Art

[0002] The manufacturing of liquid crystal panels and semiconductors requires the discharge of large quantities of waste phosphoric acid-nitric acid-acetic acid liquid (hereinafter referred to as "waste phosphoric acid"). Waste phosphoric acid is a hazardous waste with high acidity and strong corrosiveness. If discharged without treatment, it will cause significant environmental pollution. Furthermore, phosphorus is a critical element in industry, making the development of waste phosphoric acid treatment and utilization technologies essential.

[0003] To this end, existing technologies for treating and utilizing waste phosphoric acid are available. For example, Chinese invention patent publication number CN110844897A discloses a waste phosphoric acid treatment line. In this patent document, ion exchange and concentration treatment are performed separately for two types of waste acid, resulting in a relatively complex system structure and high costs. Utility Model Content

[0004] The utility model provides a comprehensive treatment system for waste phosphoric acid, which simplifies the overall structure and reduces the cost of the system.

[0005] In order to solve the above problems, the present invention adopts the following technical solutions:

[0006] An embodiment of the utility model provides a comprehensive treatment system for waste phosphoric acid, comprising a waste phosphoric acid tank, an ammonia water tank, a reaction tank, a filter, an ion exchange device, a crystallizer, a centrifuge, a drying device, and a concentrating device; the waste phosphoric acid tank and the ammonia water tank are both connected to the reaction tank, and the reaction tank is used for reacting the waste phosphoric acid with the ammonia water; the reaction tank, the filter, the ion exchange device, the crystallizer, the centrifuge, and the drying device are connected in sequence, the filter is used for filtering the solution after the reaction, the ion exchange device is used for removing metal ions in the solution, the crystallizer is used for crystallizing ammonium dihydrogen phosphate, the centrifuge is used for centrifugally separating wet ammonium dihydrogen phosphate, and the drying device is used for drying the wet ammonium dihydrogen phosphate to obtain ammonium dihydrogen phosphate; the concentrating device is respectively connected to the centrifuge and the crystallizer, and the concentrating device is used for concentrating the mother liquor after centrifugation and transporting the concentrated solution to the crystallizer.

[0007] In some embodiments, a waste gas collection device is further included, which is connected to the drying device to collect waste gas generated during the drying process.

[0008] In some embodiments, the system further includes an exhaust gas treatment system connected to the reaction tank for collecting and treating the exhaust gas in the reaction tank.

[0009] In some embodiments, the exhaust gas treatment system includes a spray tower and an air filter.

[0010] In some embodiments, a waste residue collection device is further included, and the waste residue collection device is connected to the filtering device to collect the filtered residue.

[0011] In some embodiments, the concentration device includes a heating device and a concentration evaporator, and the centrifuge, heating device, concentration evaporator and crystallization device are connected in sequence. The heating device is used to preheat the mother liquor after centrifugation, and the concentration evaporator is used to evaporate and concentrate the mother liquor.

[0012] In some embodiments, the heating device includes a heat exchanger, a water inlet pipe, a water outlet pipe, a circulation pump and a condenser. The heat exchanger includes two heat exchange channels for heat exchange, wherein the two ends of one heat exchange channel are respectively connected to the centrifuge and the concentrating evaporator, and one end of the other heat exchange channel, the water outlet pipe, the condenser, the water inlet pipe and the other end of the other heat exchange channel are connected in sequence, and the circulation pump is provided in the water outlet pipe.

[0013] In some embodiments, the concentrating evaporator is further connected to a condenser to transport steam generated by concentrating evaporation to the condenser.

[0014] In some embodiments, a condensed water collection tank is further included, which is connected to the condenser to collect condensed water.

[0015] The present invention has at least the following beneficial effects: the ion exchange device of the present invention is used to remove metal ions in the solution; the crystallization device performs crystallization treatment on the solution after ion exchange to precipitate ammonium dihydrogen phosphate; the centrifuge separates the wet ammonium dihydrogen phosphate; the drying device is used to dry the wet ammonium dihydrogen phosphate to obtain ammonium dihydrogen phosphate; and the mother liquor after centrifugation is concentrated by the concentrating device and then transported to the crystallization device for further crystallization; therefore, the present invention does not perform ion exchange and concentration on two types of waste phosphoric acid separately, but adopts the same production line for processing, thereby eliminating some devices, simplifying the overall structure, and reducing the construction cost of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a structural schematic diagram of a comprehensive treatment system for waste phosphoric acid according to an embodiment of the present invention.

[0017] Wherein, the accompanying drawings are marked as follows:

[0018] Waste phosphoric acid tank 110, ammonia water tank 120;

[0019] Reaction tank 200;

[0020] Filtering device 300, waste residue collecting device 310;

[0021] Ion exchange device 400;

[0022] Crystallization device 500;

[0023] Centrifuge 600;

[0024] Drying device 700, exhaust gas collection device 710;

[0025] Concentrating device 800, concentrating evaporator 810, heat exchanger 820, water outlet pipe 830, circulating pump 840, condenser 850, water inlet pipe 860, condensed water collection tank 870;

[0026] Exhaust gas treatment system 900, spray tower 910, air filter 920. DETAILED DESCRIPTION

[0027] The following description of the present invention, with reference to the accompanying drawings, is provided to facilitate a more comprehensive understanding of the various embodiments of the present invention as defined in the claims and their equivalents. The description includes various specific details to assist understanding, but these details should be construed as merely exemplary. Therefore, those skilled in the art will recognize that various changes and modifications may be made to the various embodiments described herein without departing from the scope and spirit of the present invention.

[0028] In the description of the present invention, descriptions of directions, such as up, down, front, back, left, right, etc., indicating directions or positional relationships, are 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 indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as a limitation on the present invention.

[0029] It will be understood that when one element (e.g., a first element) is “connected” to another element (e.g., a second element), the element may be directly connected to the other element or an intervening element (e.g., a third element) may be present between the element and the other element.

[0030] The embodiment of the present utility model provides a comprehensive treatment system for waste phosphoric acid, such as Figure 1As shown, the system includes a waste phosphoric acid tank 110, an ammonia water tank 120, a reaction tank 200, a filtration device 300, an ion exchange device 400, a crystallization device 500, a centrifuge 600, a drying device 700, and a concentration device 800. The waste phosphoric acid tank 110 is loaded with waste phosphoric acid, and the ammonia water tank 120 is loaded with ammonia water. Both the waste phosphoric acid tank 110 and the ammonia water tank 120 are connected to the reaction tank 200 to transport the waste phosphoric acid and ammonia water to the reaction tank 200. The reaction tank 200 allows the waste phosphoric acid and ammonia water to react and adjusts the pH value of the solution so that the pH value is preferably maintained between 3.5 and 4.0.

[0031] The reaction tank 200, the filter device 300, the ion exchange device 400, the crystallizer 500, the centrifuge 600, and the drying device 700 are connected in sequence. The filter device 300 filters the reacted solution to remove impurities, making the solution relatively clean. The ion exchange device 400 uses ion exchange resin to remove metal ions such as aluminum and copper from the solution. The filtered and ion exchanged solution is then transported to the crystallizer 500. The crystallizer 500 crystallizes ammonium dihydrogen phosphate, which is then transported along with the solution to the centrifuge 600. The centrifuge 600 separates the wet ammonium dihydrogen phosphate, which is then dried by the drying device 700 to produce solid ammonium dihydrogen phosphate. The concentrator 800 is connected to the centrifuge 600 and the crystallizer 500, respectively. The mother liquor separated by centrifugation is then transported to the concentrator 800. The concentrator 800 concentrates the mother liquor and transports the concentrated solution to the crystallizer 500, where the crystallizer 500 continues the crystallization process.

[0032] Therefore, this embodiment does not perform differentiated treatment on waste phosphoric acid. The ion exchange device 400 and the concentration device 800 are in the same treatment line. Compared with the traditional treatment system, some devices are omitted, thereby simplifying the overall structure of the system and reducing the construction cost of the system.

[0033] In some embodiments, the integrated waste phosphoric acid treatment system further includes a waste gas collection device 710, which is connected to the drying device 700 to collect waste gases generated during the drying process. Diammonium dihydrogen phosphate decomposes at 100°C to produce ammonia and phosphoric acid. While the drying temperature should be controlled between 80°C and 100°C, ammonia may occasionally be produced. Therefore, waste gas collection device 710 collects these gases, including ammonia, to prevent direct release into the atmosphere and reduce environmental pollution.

[0034] In some embodiments, the integrated waste phosphoric acid treatment system further includes a waste gas treatment system 900, which is connected to the reaction tank 200 to collect and treat waste gas from the reaction tank 200. Waste gases such as ammonia are generated in the reaction tank 200, and the waste gas treatment system 900 can collect and treat these waste gases to prevent them from being directly discharged into the atmosphere, thereby reducing environmental pollution.

[0035] Furthermore, the exhaust gas treatment system 900 includes a spray tower 910 and an air filter 920. The exhaust gas first passes through the spray tower 910 for spray treatment to remove dust. The sprayed gas then passes through the air filter 920, which filters out harmful gases. The treated gas can be directly discharged into the atmosphere. The air filter 920 can specifically include an activated carbon adsorption device.

[0036] In some embodiments, the integrated waste phosphoric acid treatment system further includes a waste residue collection device 310, which is connected to the filter device 300 to collect the filtered residue. The collected residue can be sent to a treatment plant or other treatment system for treatment, avoiding direct discharge and environmental pollution.

[0037] The filtering device 300 may be a filter press.

[0038] In some embodiments, the concentrating device 800 includes a heating device and a concentrating evaporator 810. The centrifuge 600, the heating device, the concentrating evaporator 810, and the crystallization device 500 are sequentially connected. The mother liquor after centrifugation is transported to the heating device, which preheats the centrifuged mother liquor to increase its temperature. The heated mother liquor then enters the concentrating evaporator 810, which evaporates and concentrates the mother liquor. Since the mother liquor is preheated, the evaporation and concentration time can be shortened, and the concentration efficiency can be improved.

[0039] Furthermore, the heating device includes a heat exchanger 820, a water inlet pipe 860, a water outlet pipe 830, a circulation pump 840 and a condenser 850. The heat exchanger 820 includes two heat exchange channels for heat exchange, wherein the two ends of one heat exchange channel are respectively connected to the centrifuge 600 and the concentrating evaporator 810, and one end of the other heat exchange channel, the water outlet pipe 830, the condenser 850, the water inlet pipe 860 and the other end of the other heat exchange channel are connected in sequence, and a circulation pump 840 is provided in the water outlet pipe 830.

[0040] When the circulation pump 840 is operating, the cold water in the outlet pipe 830 is fed into the condenser 850, which heats the cold water. This causes the inlet pipe 860 to feed hot water to the heat exchanger 820. The hot water then exchanges heat with the centrifuged mother liquor to preheat the centrifuged mother liquor. The preheated mother liquor is then fed to the concentrating evaporator 810. Due to the heat exchange, the hot water in the inlet pipe 860 cools down, flows out of the outlet pipe 830, and reenters the condenser 850 to continue heating the mother liquor.

[0041] Furthermore, the concentrating evaporator 810 is also connected to the condenser 850 to transport the steam generated by the concentrating evaporation to the condenser 850. The steam will exchange heat with the water in the water inlet pipe 860 to heat the water in the water inlet pipe 860. This makes rational use of the steam generated by the concentrating evaporator 810, and there is no need to configure an additional heating device for the condenser 850, thereby reducing energy consumption.

[0042] In some embodiments, the comprehensive treatment system for waste phosphoric acid further includes a condensate collection tank 870, which is connected to the condenser 850 to collect condensate. Since the steam from the concentrating evaporator 810 contains other substances during condensation and evaporation, these substances are collected by the condensate collection tank 870 for easy processing and reuse.

[0043] The terms and words used in the above description and claims are not limited to their literal meanings, but are merely used by the applicant to enable a clear and consistent understanding of the present invention. Therefore, it should be clear to those skilled in the art that the above description of various embodiments of the present invention is provided for illustration only and is not intended to limit the present invention as defined in the appended claims and their equivalents.

Claims

1. A comprehensive treatment system for waste phosphoric acid, characterized by: The invention comprises a waste phosphoric acid tank, an ammonia water tank, a reaction tank, a filter, an ion exchange device, a crystallizer, a centrifuge, a drying device and a concentrating device; the waste phosphoric acid tank and the ammonia water tank are both connected to the reaction tank, and the reaction tank is used for reacting the waste phosphoric acid with the ammonia water; the reaction tank, the filter, the ion exchange device, the crystallizer, the centrifuge and the drying device are connected in sequence, the filter is used for filtering the solution after the reaction, the ion exchange device is used for removing metal ions in the solution, the crystallizer is used for crystallizing and precipitating ammonium dihydrogen phosphate, the centrifuge is used for centrifugally separating wet ammonium dihydrogen phosphate, and the drying device is used for drying the wet ammonium dihydrogen phosphate to obtain ammonium dihydrogen phosphate; the concentrating device is respectively connected to the centrifuge and the crystallizer, and the concentrating device is used for concentrating the mother liquor after centrifugation and transporting the concentrated solution to the crystallizer.

2. The comprehensive treatment system for waste phosphoric acid according to claim 1, characterized in that: It also includes a waste gas collection device, which is connected to the drying device to collect waste gas generated during the drying process.

3. The comprehensive treatment system for waste phosphoric acid according to claim 1, characterized in that: The invention also comprises an exhaust gas treatment system, which is connected to the reaction tank and is used for collecting and treating the exhaust gas in the reaction tank.

4. The comprehensive treatment system for waste phosphoric acid according to claim 3, characterized in that: The exhaust gas treatment system includes a spray tower and an air filter.

5. The comprehensive treatment system for waste phosphoric acid according to claim 1, characterized in that: It also includes a waste residue collecting device, which is connected to the filtering device and is used to collect the filtered residue.

6. The comprehensive treatment system for waste phosphoric acid according to any one of claims 1 to 5, characterized in that: The concentrating device includes a heating device and a concentrating evaporator. The centrifuge, heating device, concentrating evaporator and crystallization device are connected in sequence. The heating device is used to preheat the mother liquor after centrifugation, and the concentrating evaporator is used to evaporate and concentrate the mother liquor.

7. The comprehensive treatment system for waste phosphoric acid according to claim 6, characterized in that: The heating device includes a heat exchanger, a water inlet pipe, a water outlet pipe, a circulation pump and a condenser. The heat exchanger includes two heat exchange channels for heat exchange, wherein the two ends of one heat exchange channel are respectively connected to the centrifuge and the concentrating evaporator, and one end of the other heat exchange channel, the water outlet pipe, the condenser, the water inlet pipe and the other end of the other heat exchange channel are sequentially connected, and the circulation pump is provided in the water outlet pipe.

8. The comprehensive treatment system for waste phosphoric acid according to claim 7, characterized in that: The concentrating evaporator is also connected to a condenser so as to transport the steam generated by concentrating evaporation to the condenser.

9. The comprehensive treatment system for waste phosphoric acid according to claim 8, characterized in that: The utility model further comprises a condensed water collecting tank, which is connected to the condenser and is used for collecting condensed water.

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