Intelligent modular device for extracting calcium fluoride by using hydrofluoric acid wastewater

Abstract

The utility model belongs to the field of high-fluorine-containing wastewater treatment, and particularly relates to an intelligent modular device for extracting calcium fluoride by utilizing hydrofluoric acid wastewater, which comprises a primary coagulation reaction tank, a secondary coagulation reaction tank and a tertiary coagulation reaction tank which are communicated in sequence, a first water inlet flange is arranged at the inlet end of the primary coagulation reaction tank, and a second water outlet flange is arranged at the outlet end of the tertiary coagulation reaction tank; the outlet end of the third-stage coagulation reaction tank is sequentially connected with a PAC and citric acid flocculation reaction tank and a PAM flocculation reaction tank, and the outlet end of the PAM flocculation reaction tank is connected with a calcium fluoride storage and extraction module device; a spraying device is arranged in each of the primary coagulation reaction tank and the secondary coagulation reaction tank; each of the coagulation reaction tank, the PAC and citric acid flocculation reaction tank and the PAM flocculation reaction tank is provided with a first aeration device, a manhole, a bottom blow-off pipeline, an integrated bottom bracket and a chemical internal circulation pump. The intelligent modularized device disclosed by the utility model is convenient to transport, mount and operate accurately, and is small in occupied area, low in investment cost and high in product purity.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the field of high fluorine containing wastewater treatment, specifically relates to a kind of intelligent modular device for extracting calcium fluoride using hydrofluoric acid wastewater. BACKGROUND

[0002] Calcium fluoride is mainly used as raw material for the production of hydrofluoric acid and metallurgical flux. In the process of photovoltaic manufacturing industry, in order to corrode the oxide layer on the surface of silicon, a large amount of hydrofluoric acid wastewater is generated in the production process, thereby causing serious pollution to the environment and wasting resources. Therefore, in order to maintain the sustainable development of China's photovoltaic industry and reduce environmental pollution, it has great economic and social benefits to treat and recycle the wastewater containing hydrofluoric acid. For the treatment of fluorine-containing industrial wastewater, the precipitation method is generally used, that is, a large amount of lime and other reagents are added to the wastewater to generate CaF2 precipitate by the reaction of fluoride ions in the wastewater with calcium ions in the lime, so as to remove the fluoride ions. This process has the advantages of simple method, convenient treatment and low cost, but the biggest disadvantage is that the generated calcium fluoride precipitate will wrap on the surface of calcium hydroxide particles, and the purity of CaF2 is low, and it also contains the residues of other reagents, so secondary purification processing is needed to improve the purity of CaF2, and the secondary processing cost is high, the occupied area is large, and a large amount of solid waste is generated. SUMMARY

[0003] The utility model aims at overcoming the deficiencies in the prior art, and provides an intelligent modular device for extracting calcium fluoride using hydrofluoric acid wastewater. The intelligent modular device can efficiently extract high-purity (85-92%) calcium fluoride from high-fluorine-containing wastewater. The wastewater treatment and extraction device is convenient to transport, install and operate accurately, has small occupied area, low investment cost and high product purity.

[0004] To achieve the above technical purposes, the utility model embodiment adopts the technical scheme of:

[0005] An intelligent modular device for extracting calcium fluoride using hydrofluoric acid wastewater, comprising a coagulation reaction tank, the coagulation reaction tank comprising a primary coagulation reaction tank, a secondary coagulation reaction tank and a tertiary coagulation reaction tank connected in sequence, a first water inlet flange is arranged at the inlet end of the primary coagulation reaction tank, the outlet end of the tertiary coagulation reaction tank is connected with a PAC and citric acid flocculation reaction tank and a PAM coagulation reaction tank in sequence, and the outlet end of the PAM coagulation reaction tank is connected with a calcium fluoride storage and extraction module device;

[0006] A hydrofluoric acid content online detector is arranged in the primary coagulation reaction tank, the hydrofluoric acid content online detector is electrically connected with a control cabinet PLC, and the control cabinet PLC controls the calcium hydroxide addition amount of the primary reaction tank feeding pump;

[0007] The primary coagulation reaction tank and the secondary coagulation reaction tank are provided with a spraying device, the secondary coagulation reaction tank is provided with a pH value tester for detecting the calcium hydroxide adding amount of the secondary reaction tank feeding pump, the pH value tester is electrically connected with a control cabinet PLC, and the control cabinet PLC controls the calcium hydroxide adding amount of the secondary reaction tank feeding pump.

[0008] The tertiary coagulation reaction tank is provided with a pH value tester for detecting the calcium hydroxide adding amount of the tertiary reaction tank feeding pump, the pH value tester is electrically connected with a control cabinet PLC, and the control cabinet PLC controls the calcium hydroxide adding amount of the tertiary reaction tank feeding pump.

[0009] The tertiary coagulation reaction tank, the PAC and citric acid flocculation reaction tank and the PAM coagulation reaction tank are provided with a stirring device.

[0010] The primary coagulation reaction tank, the secondary coagulation reaction tank, the tertiary coagulation reaction tank, the PAC and citric acid flocculation reaction tank and the PAM coagulation reaction tank are provided with a first aeration device and a chemical internal circulating pump, and the first aeration device is connected with a first air compressor.

[0011] Further, the primary coagulation reaction tank, the secondary coagulation reaction tank, the tertiary coagulation reaction tank, the PAC and citric acid flocculation reaction tank and the PAM coagulation reaction tank are provided with an electromagnetic flowmeter for detecting the adding amount, and the electromagnetic flowmeter is electrically connected with the control cabinet PLC.

[0012] Further, the pH value in the secondary coagulation reaction tank is stabilized at 6-7.

[0013] If the pH value is less than 6, the secondary reaction tank feeding pump is started to add calcium hydroxide; if the pH value is greater than 7, the addition of calcium hydroxide is stopped.

[0014] Further, the pH value in the tertiary coagulation reaction tank is stabilized at 7.5-8.

[0015] If the pH value is less than 7.5, the tertiary reaction tank feeding pump is started to add calcium hydroxide; if the pH value is greater than 8, the addition of calcium hydroxide is stopped.

[0016] Further, the PAC and citric acid flocculation reaction tank is provided with a PAC automatic drug storage device and a citric acid automatic drug storage device, and the adding amount of the PAC automatic drug storage device and the citric acid automatic drug storage device is controlled by the control cabinet PLC.

[0017] Further, the PAM coagulation reaction tank is provided with a PAM automatic material device, and the adding amount of the PAM automatic material device is controlled by the control cabinet PLC.

[0018] Further, the calcium fluoride storage and extraction module device comprises a storage box, a pneumatic diaphragm pump and a filter press connected in sequence, the calcium fluoride flocculation liquid enters the storage box from the second water inlet flange, and a second aeration device is arranged in the storage box and connected with the second air compressor.

[0019] Further, the primary reaction tank feeding pump, the secondary reaction tank feeding pump and the tertiary reaction tank feeding pump are connected with a calcium hydroxide bucket, and the calcium hydroxide bucket is used for storing calcium hydroxide.

[0020] The beneficial effects brought by the technical scheme provided in the embodiment of the utility model are:

[0021] 1. The utility model discloses a primary reaction tank feeding pump, a secondary reaction tank feeding pump and a tertiary reaction tank feeding pump are connected with a calcium hydroxide bucket, and the calcium hydroxide bucket is used for storing calcium hydroxide.

[0022] 2. The hydrogen fluoride acid wastewater is reacted with calcium hydroxide in the primary coagulation reaction tank, the secondary coagulation reaction tank and the tertiary coagulation reaction tank, and the mixture is quantitatively added with PAC and mixed with citric acid to generate flocculation, and then is reacted with PAM to form calcium fluoride, and the mixture of the finished product calcium fluoride and water is squeezed by the high-pressure diaphragm plate and frame filter press, the finished product calcium fluoride (dry cake sludge with water content below 50%) is left between the filter plates after extrusion, the filtrate flows into the water collecting tank through the filter plate channel and is discharged into the sewage treatment station, and the purity of the finished product calcium fluoride reaches 85-92%. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is the structure schematic view of the intelligent modular device for extracting calcium fluoride from hydrogen fluoride acid wastewater in the embodiment of the utility model.

[0024] Figure 2 It is Figure 1 The structure schematic view of the coagulation reaction tank and the flocculation reaction tank in the intelligent modular device.

[0025] Figure 3 It is Figure 1 The structure schematic view of the calcium fluoride storage and extraction module device in the intelligent modular device.

[0026] Explanation of reference numerals in the attached drawings: 1-Primary coagulation reaction tank; 2-First inlet flange; 3-First aeration device; 4-Inspection hole; 5-Bottom drain pipe; 6-Integrated base support; 7-Chemical internal circulation pump; 8-Spraying device; 9-pH meter; 10-Stirring device; 11-Secondary coagulation reaction tank; 12-Tertiary coagulation reaction tank; 13-First air compressor; 14-PAC and citric acid flocculation reaction tank; 15-PAM coagulation reaction tank; 16-Primary reaction tank feed pump; 17-Secondary reaction tank feed pump; 18-Tertiary reaction tank feed pump; 19-Calcium hydroxide tank; 20-PAC automated chemical storage device; 21-Citral acid automated chemical storage device; 22-PAM automated material storage device; 23-Second inlet flange; 24-Storage tank; 25-Second aeration device; 26-Pneumatic diaphragm pump; 27-Second air compressor; 28-Filter press. Detailed Implementation

[0027] In the description of this utility model, it should be understood that the directional terms such as "inner" and "outer", "upper" and "lower", "left" and "right" indicate the orientation or positional relationship, which are usually based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the scope of protection of this utility model.

[0028] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this utility model and are not intended to limit this utility model.

[0029] Example 1

[0030] like Figures 1-3 As shown, an intelligent modular device for extracting calcium fluoride from hydrofluoric acid wastewater includes a coagulation reaction tank. The coagulation reaction tank includes a primary coagulation reaction tank 1, a secondary coagulation reaction tank 11, and a tertiary coagulation reaction tank 12 connected in sequence. The inlet end of the primary coagulation reaction tank 1 is provided with a first inlet flange 2. The outlet end of the tertiary coagulation reaction tank 12 is connected in sequence to a PAC and citric acid flocculation reaction tank 14 and a PAM coagulation reaction tank 15. The outlet end of the PAM coagulation reaction tank 15 is connected to a calcium fluoride storage and extraction module device.

[0031] An online hydrofluoric acid content detector is installed in the primary coagulation reaction tank 1. The online hydrofluoric acid content detector is electrically connected to the control cabinet PLC. The control cabinet PLC controls the amount of calcium hydroxide added by the primary reaction tank feed pump 16.

[0032] The primary coagulation reaction tank 1 and the secondary coagulation reaction tank 11 are provided with a spraying device 8, the secondary coagulation reaction tank 11 is provided with a pH value tester 9 for detecting the calcium hydroxide adding amount of the secondary reaction tank feeding pump 17, the pH value tester 9 is electrically connected with the control cabinet PLC, and the control cabinet PLC controls the calcium hydroxide adding amount of the secondary reaction tank feeding pump 17;

[0033] The tertiary coagulation reaction tank 12 is provided with a pH value tester 9 for detecting the calcium hydroxide adding amount of the tertiary reaction tank feeding pump 18, the pH value tester 9 is electrically connected with the control cabinet PLC, and the control cabinet PLC controls the calcium hydroxide adding amount of the tertiary reaction tank feeding pump 18;

[0034] The tertiary coagulation reaction tank 12, the PAC (polyaluminum chloride) and the citric acid flocculation reaction tank 14 and the PAM (polyacrylamide) coagulation reaction tank 15 are provided with a stirring device 10;

[0035] The primary coagulation reaction tank 1, the secondary coagulation reaction tank 11, the tertiary coagulation reaction tank 12, the PAC and the citric acid flocculation reaction tank 14 and the PAM coagulation reaction tank 15 are provided with a first aeration device 3 and a chemical internal circulating pump 7, and are also provided with an access hole 4, a bottom blowdown pipeline 5 and an integrated bottom support 6, and the first aeration device 3 is connected with a first air compressor 13.

[0036] The primary coagulation reaction tank 1, the secondary coagulation reaction tank 11, the tertiary coagulation reaction tank 12, the PAC and the citric acid flocculation reaction tank 14 and the PAM coagulation reaction tank 15 are provided with an electromagnetic flowmeter for detecting the adding amount, and the electromagnetic flowmeter is electrically connected with the control cabinet PLC.

[0037] The pH value in the secondary coagulation reaction tank 11 is stabilized at 6-7;

[0038] If the pH value is less than 6, the secondary reaction tank feeding pump 17 is started to add calcium hydroxide; if the pH value is greater than 7, the adding of calcium hydroxide is stopped.

[0039] The pH value in the tertiary coagulation reaction tank 12 is stabilized at 7.5-8;

[0040] If the pH value is less than 7.5, the tertiary reaction tank feeding pump 18 is started to add calcium hydroxide; if the pH value is greater than 8, the adding of calcium hydroxide is stopped.

[0041] The PAC and the citric acid flocculation reaction tank 14 is provided with a PAC automatic drug storage device 20 and a citric acid automatic drug storage device 21, and the adding amount of the PAC automatic drug storage device 20 and the citric acid automatic drug storage device 21 is controlled by the control cabinet PLC.

[0042] The PAM coagulation reaction tank 15 is provided with a PAM automatic material device 22, and the adding amount of the PAM automatic material device 22 is controlled by the control cabinet PLC.

[0043] The calcium fluoride storage and extraction module device comprises a storage box 24, a pneumatic diaphragm pump 26 and a filter press 28 connected in sequence. The calcium fluoride flocculation liquid enters the storage box 24 from the second water inlet flange 23. The second aeration device 25 is arranged in the storage box 24 and is connected with the second air compressor 27.

[0044] The primary coagulation reaction tank 1 is a primary reaction tank of raw water (hydrofluoric acid wastewater) and calcium hydroxide. The raw water is lifted to the primary coagulation reaction tank 1 through the first water inlet flange 2. The hydrogen fluoride content and the raw water flow data detected by the electromagnetic flowmeter and the hydrogen fluoride content online detector are transmitted to the control cabinet PLC. The control cabinet PLC automatically calculates the required setting amount of calcium hydroxide and controls the intelligent feeding of the primary reaction tank feeding pump 16. The first aeration device 3 and the circulating chemical pump 7 are used to ensure that the hydrogen fluoride and the calcium hydroxide are fully reacted. At the same time, the spraying device 8 sprays the circulating liquid in the primary coagulation reaction tank 1 to eliminate the foam generated in the mixing and circulating process. Part of the impurities and unreacted precipitates are automatically discharged through the bottom blowdown pipe 5 at regular intervals.

[0045] The effluent of the primary coagulation reaction tank 1 enters the secondary coagulation reaction tank 11. The pH value detector 9 is used to determine the amount of calcium hydroxide to be added. The secondary reaction tank feeding pump 17 is used for intelligent feeding to ensure that the pH value in the secondary coagulation reaction tank 11 is stable between 6 and 7. The first aeration device 3 and the circulating chemical pump 7 are used to ensure that the hydrogen fluoride and the calcium hydroxide are fully reacted. At the same time, the spraying device 8 sprays the circulating liquid in the secondary coagulation reaction tank 11 to eliminate the foam generated in the mixing and circulating process. Part of the impurities and unreacted precipitates are automatically discharged through the bottom blowdown pipe 5 at regular intervals.

[0046] The effluent of the secondary coagulation reaction tank 11 enters the tertiary coagulation reaction tank 12. The pH value detector 9 is used to determine the precise amount of calcium hydroxide to be added. The tertiary reaction tank feeding pump 18 is used for precise feeding to ensure that the pH value in the tertiary coagulation reaction tank 12 is stable between 7.5 and 8. The stirring pump 10 and the circulating chemical pump 7 are used to ensure that the hydrogen fluoride and the calcium hydroxide are fully reacted. Part of the impurities and unreacted precipitates are automatically discharged through the bottom blowdown pipe 5 at regular intervals.

[0047] The effluent of the tertiary coagulation reaction tank 12 enters the PAC and citric acid flocculation reaction tank 14. The electromagnetic flowmeter transmits the detected raw water flow data to the control cabinet PLC. The control cabinet PLC controls the PAC automatic drug storage tank 20 and the citric acid automatic drug storage device 21 to add drugs. After PAC polyaluminum chloride and citric acid are added at the same time, stirring and circulating mixing reaction are carried out. Part of the impurities and unreacted precipitates are automatically discharged through the bottom blowdown pipe 5 at regular intervals.

[0048] The water from the PAC and citric acid flocculation reaction tank 14 enters the PAM coagulation reaction tank 15, the electromagnetic flowmeter transmits the detected raw water flow data to the control cabinet PLC, the control cabinet PLC controls the PAM automatic feeding device 22 to add chemicals, after the addition of PAM macromolecules, stirring and circulating mixing reaction are carried out, part of sundries and precipitates not participating in the reaction are automatically discharged through the bottom blowdown pipe 5 at regular time;

[0049] The calcium fluoride flocculation liquid from the PAM coagulation reaction tank 15 enters the storage tank 24 through the second water inlet flange 23, is aerated by the second aeration device 25 in the storage tank 24, so that the calcium fluoride flocculation liquid is more uniform and stable, then enters the filter press 28 through the pneumatic diaphragm pump 26, the finished product calcium fluoride is left between the filter plates after extrusion, the purity of the finished product calcium fluoride is 85%-92%; the filtrate filtered out flows into the water collecting tank through the filter plate channel and is discharged into the sewage treatment station.

[0050] The primary reaction tank feeding pump 16, the secondary reaction tank feeding pump 17 and the tertiary reaction tank feeding pump 18 are connected with the calcium hydroxide tank 19, and the calcium hydroxide tank 19 is used for storing calcium hydroxide.

[0051] Finally, it should be explained that the above specific embodiments are only used to illustrate the technical solutions of the utility model and not to limit, although the utility model is described in detail with reference to examples, those skilled in the art should understand that the technical solutions of the utility model can be modified or replaced equivalently without departing from the spirit and scope of the technical solutions of the utility model, and they should be covered in the scope of the claims of the utility model.

Claims

1. An intelligent modular device for extraction of calcium fluoride using hydrofluoric acid wastewater characterized in that, The coagulation reaction tank comprises a primary coagulation reaction tank (1), a secondary coagulation reaction tank (11) and a tertiary coagulation reaction tank (12) connected in sequence, a first water inlet flange (2) is arranged at the inlet end of the primary coagulation reaction tank (1), the outlet end of the tertiary coagulation reaction tank (12) is connected with a PAC and citric acid flocculation reaction tank (14) and a PAM coagulation reaction tank (15) in sequence, and the outlet end of the PAM coagulation reaction tank (15) is connected with a calcium fluoride storage and extraction module device. A hydrogen fluoride content on-line detector is arranged in the primary coagulation reaction tank (1), the hydrogen fluoride content on-line detector is electrically connected with a control cabinet PLC, and the control cabinet PLC controls the calcium hydroxide addition amount of a primary reaction tank feeding pump (16). Spraying devices (8) are arranged in the primary coagulation reaction tank (1) and the secondary coagulation reaction tank (11), a pH value detector (9) is arranged in the secondary coagulation reaction tank (11) and used for detecting the calcium hydroxide addition amount of a secondary reaction tank feeding pump (17), the pH value detector (9) is electrically connected with the control cabinet PLC, and the control cabinet PLC controls the calcium hydroxide addition amount of the secondary reaction tank feeding pump (17). A pH value detector (9) is arranged in the tertiary coagulation reaction tank (12) and used for detecting the calcium hydroxide addition amount of a tertiary reaction tank feeding pump (18), the pH value detector (9) is electrically connected with the control cabinet PLC, and the control cabinet PLC controls the calcium hydroxide addition amount of the tertiary reaction tank feeding pump (18). Stirring devices (10) are arranged in the tertiary coagulation reaction tank (12), the PAC and citric acid flocculation reaction tank (14) and the PAM coagulation reaction tank (15). The primary coagulation reaction tank (1), the secondary coagulation reaction tank (11), the tertiary coagulation reaction tank (12), the PAC and citric acid flocculation reaction tank (14) and the PAM coagulation reaction tank (15) are all provided with first aeration devices (3) and chemical internal circulating pumps (7), and the first aeration devices (3) are connected with first air compressors (13).

2. The intelligent modular device for extraction of calcium fluoride using hydrofluoric acid wastewater as claimed in claim 1, wherein, The primary coagulation reaction tank (1), the secondary coagulation reaction tank (11), the tertiary coagulation reaction tank (12), the PAC and citric acid flocculation reaction tank (14) and the PAM coagulation reaction tank (15) are all provided with electromagnetic flowmeters for detecting the dosing amount, and the electromagnetic flowmeters are electrically connected with the control cabinet PLC.

3. The intelligent modular device for extraction of calcium fluoride using hydrofluoric acid wastewater as claimed in claim 1, wherein, The PAC and citric acid flocculation reaction tank (14) is provided with a PAC automatic drug storage device (20) and a citric acid automatic drug storage device (21), and the dosing amount of the PAC automatic drug storage device (20) and the citric acid automatic drug storage device (21) is controlled by the control cabinet PLC.

4. The intelligent modular device for extraction of calcium fluoride using hydrofluoric acid wastewater as claimed in claim 1, wherein, The PAM coagulation reaction tank (15) is provided with a PAM automatic material device (22), and the dosing amount of the PAM automatic material device (22) is controlled by the control cabinet PLC.

5. The intelligent modular device for extraction of calcium fluoride using hydrofluoric acid wastewater as claimed in claim 1, wherein, The calcium fluoride storage and extraction module device comprises a storage box (24), a pneumatic diaphragm pump (26) and a filter press (28) connected in sequence, calcium fluoride flocculation liquid enters the storage box (24) from the second water inlet flange (23), the second aeration device (25) is arranged in the storage box (24), and the second aeration device (25) is connected with the second air compressor (27).

6. The intelligent modular device for extraction of calcium fluoride using hydrofluoric acid wastewater as claimed in claim 1, wherein, The primary reaction pool feeding pump (16), the secondary reaction pool feeding pump (17) and the tertiary reaction pool feeding pump (18) are connected with the calcium hydroxide bucket (19), and the calcium hydroxide bucket (19) is used for storing calcium hydroxide.

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