An integrated device for pretreatment of iron phosphate wastewater

Abstract

The utility model discloses an integrated device for pre-treatment of ferric phosphate wastewater, comprising a pH neutralization system, a heavy metal reaction system, a flocculation precipitation system and a clarification system arranged in sequence along the flow direction of the ferric phosphate wastewater; the clarification system is used to perform solid-liquid separation on the wastewater treated by the flocculation precipitation system. The utility model occupies a small area, can effectively reduce investment and operating costs, and realizes an effective combination of social value and economic value. At the same time, the utility model performs processes such as neutralization, reaction, flocculation, and clarification on the ferric phosphate wastewater through an integrated device, and can remove most of the metal ions, and finally achieve the water production reaching the water inlet standard of membrane concentration, so as to achieve the purpose of waste salt recovery for the subsequent evaporation and crystallization of monoammonium phosphate concentrated solution.

Description

Technical Field

[0001] The utility model relates to the technical field of high-salt chemical wastewater treatment, in particular to an integrated device for pre-treating iron phosphate wastewater. Background Art

[0002] With the rapid development of new energy technology, the market demand for lithium iron phosphate batteries has increased dramatically, and the demand for its raw material iron phosphate has also increased dramatically. However, in the production process of iron phosphate, the discharge of high-salt wastewater is increasing day by day. At present, the high-salt wastewater is mainly treated by a combination of membrane concentration and evaporation crystallization, with the goal of achieving zero discharge of high-salt wastewater and recycling of waste salt resources.

[0003] In traditional membrane concentration treatment, the double alkali method of sodium carbonate and sodium hydroxide is often used. However, this treatment method still has the following problems: first, the sodium sulfate and sodium phosphate produced in the end cannot be effectively utilized, which not only causes waste of resources but also generates high hazardous waste disposal costs; second, this method requires more equipment, occupies a large area and also increases investment and operating costs. Utility Model Content

[0004] In view of the deficiencies existing in the prior art, the utility model provides an integrated device for pre-treating iron phosphate wastewater.

[0005] The utility model discloses an integrated device for pre-treating ferric phosphate wastewater, comprising a pH neutralization system, a heavy metal reaction system, a flocculation precipitation system and a clarification system which are sequentially arranged along the flow direction of the ferric phosphate wastewater;

[0006] The clarification system is used to separate solid from liquid in the wastewater after being treated by the flocculation and sedimentation system.

[0007] As a further improvement of the utility model, the pH neutralization system includes a neutralization tank, the heavy metal reaction system includes a reaction tank, the flocculation precipitation system includes a flocculation tank, and the clarification system includes a clarifier;

[0008] The neutralization tank, the reaction tank and the flocculation tank are arranged side by side to form a triple box, and the triple box is connected with the clarifier through upper and lower baffles so that the water treated by the flocculation tank flows into the clarifier from bottom to top.

[0009] As a further improvement of the utility model, in the triple box, an upper baffle is provided between the neutralization tank and the reaction tank, and a lower baffle is provided between the reaction tank and the flocculation tank;

[0010] The bottom end of the upper baffle plate and the top end of the lower baffle plate form a channel for waste water to flow.

[0011] As a further improvement of the utility model, a wastewater inlet and a first dosing port for adding ammonia water are provided on the neutralization tank, a first agitator is provided in the neutralization tank, and a neutralization tank drain port is provided at the bottom of the neutralization tank.

[0012] As a further improvement of the utility model, a second dosing port for adding organic sulfur or sodium sulfide is provided on the reaction tank, and a second agitator is provided in the reaction tank.

[0013] As a further improvement of the utility model, a third dosing port for adding flocculant is provided on the flocculation tank, and a third agitator is provided in the flocculation tank.

[0014] As a further improvement of the utility model, the flocculant is polyaluminium ferric sulfate.

[0015] As a further improvement of the utility model, the clarifier is provided with a clear water zone, a honeycomb inclined plate filler layer and a sludge separation zone in order from top to bottom;

[0016] The clarifier is provided with a sawtooth overflow weir at a position corresponding to the clean water zone, and a clean water discharge port is provided at the outlet of the sawtooth overflow weir, and the clean water discharge port transports the treated clean water to other equipment or places through a clean water delivery pump; the clarifier is provided with a scraper in the sludge separation zone corresponding to the sludge separation zone, and a sludge discharge port is provided at the bottom of the clarifier corresponding to the sludge separation zone, and the scraper is used to transport the precipitated sludge to the sludge discharge port, and the sludge discharge port transports the treated sludge to other equipment or places through a sludge delivery pump; the clarifier is also provided with a sludge emptying port at a position corresponding to the sludge separation zone.

[0017] As a further improvement of the utility model, the height of the honeycomb inclined plate packing layer is 0.8-1m, and the inclination angle of the honeycomb inclined plate packing layer is 60°;

[0018] The distance between the honeycomb inclined plate filler layer and the sawtooth overflow weir is 1 m, and the distance between the honeycomb inclined plate filler layer and the sludge separation zone is 2-3 m.

[0019] As a further improvement of the utility model, the clarifier is further provided with a fourth dosing port for adding a coagulant aid at a position corresponding to the sludge separation zone.

[0020] Compared with the prior art, the beneficial effects of the utility model are:

[0021] The utility model realizes efficient pretreatment of iron phosphate wastewater by setting up a pH neutralization system, a heavy metal reaction system, a flocculation sedimentation system and a clarification system, and by using an integrated device, it saves equipment investment costs and also saves floor space, thus realizing an effective combination of social value and economic value;

[0022] The utility model is provided with a pH neutralization system, a heavy metal reaction system, a flocculation precipitation system and a clarification system, which can carry out neutralization, reaction, flocculation and clarification processes on iron phosphate wastewater, remove most of the metal ions, and finally achieve water production that meets the water inlet standard of membrane concentration, thus providing a guarantee for the subsequent evaporation and crystallization of monoammonium phosphate concentrated solution to achieve the purpose of waste salt recovery. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic structural diagram of an integrated device for pretreating iron phosphate wastewater disclosed in an embodiment of the utility model.

[0024] In the figure:

[0025] 1. Wastewater inlet; 2. Neutralization tank; 3. Neutralization tank outlet; 4. First agitator; 5. Reaction tank; 6. Second agitator; 7. Flocculation tank; 8. Third agitator; 9. Clarifier; 10. Sludge scraper; 11. Honeycomb inclined plate packing layer; 12. Clean water outlet; 13. Clean water delivery pump; 14. Sludge outlet; 15. Sludge discharge outlet; 16. Sludge delivery pump. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all of the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0027] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0028] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0029] The utility model is further described in detail below in conjunction with the accompanying drawings:

[0030] like Figure 1 As shown, an integrated device for pretreatment of ferric phosphate wastewater provided by the utility model comprises a pH neutralization system, a heavy metal reaction system, a flocculation sedimentation system and a clarification system which are sequentially arranged along the flow direction of the ferric phosphate wastewater; wherein the pH neutralization system is used to adjust the pH value of the ferric phosphate wastewater flowing therethrough; the heavy metal reaction system is used to precipitate the heavy metal ions in the ferric phosphate wastewater flowing therethrough, and the flocculation sedimentation system is used to further remove suspended matter and metal ions in the ferric phosphate wastewater flowing therethrough; and the clarification system is used to clarify and concentrate the sludge so as to perform solid-liquid separation on the wastewater after treatment by the flocculation sedimentation system.

[0031] In this embodiment, by setting up a pH neutralization system, a heavy metal reaction system, a flocculation and sedimentation system and a clarification system, efficient pretreatment of ferric phosphate wastewater is achieved, and by using an integrated treatment equipment, the equipment investment cost is saved while also saving floor space, thereby achieving an effective combination of social value and economic value; the ferric phosphate wastewater treated by the pH neutralization system, the heavy metal reaction system and the flocculation and sedimentation system can meet the water inlet standard of membrane concentration after being clarified by the clarification system, thus providing a guarantee for the subsequent evaporation and crystallization of ammonium phosphate concentrate to achieve the purpose of waste salt recovery.

[0032] Specific:

[0033] Example:

[0034] The TDS of the iron phosphate wastewater in this example is usually more than 50000 mg / L, and the cations are mainly Ca 2+ Mg 2+ , Fe 3 + , Mn 2+ Metal ions, anions are mainly SO4 2- and PO4 3- and a small amount of C l - The membrane concentration process and evaporation crystallization process are prone to scaling and clogging, and have high requirements for pretreatment.

[0035] like Figure 1 As shown, in the above embodiment, preferably, the pH neutralization system includes a neutralization tank 2, the heavy metal reaction system includes a reaction tank 5, the flocculation sedimentation system includes a flocculation tank 7, and the clarification system includes a clarifier 9; wherein the neutralization tank 2, the reaction tank 5 and the flocculation tank 7 are arranged side by side to form a triple box; in the triple box, the neutralization tank 2, the reaction tank 5 and the flocculation tank 7 are divided and connected by a baffle, specifically: in the triple box, the neutralization tank 2 and the reaction tank 5 share an upper baffle, the upper baffle is arranged in a vertical direction, and the top end is connected to the top wall of the triple box body; the reaction tank 5 and the flocculation tank 7 share a lower baffle, the lower baffle is arranged in a vertical direction, and the bottom end is connected to the bottom wall of the triple box body; the bottom end of the upper baffle and the top end of the lower baffle together form a channel for wastewater circulation.

[0036] In the above embodiment, preferably, the triple box is connected to the clarifier through upper and lower baffles. Specifically, a lower baffle and an upper baffle are arranged between the outlet side of the flocculation tank 7 in the triple box and the clarifier 9. In this embodiment, the triple box composed of the neutralization tank 2, the reaction tank 5 and the flocculation tank 7 is connected to the clarifier 9 through upper and lower baffles, which not only saves the box material, but also saves the pipeline and the delivery pump, and at the same time increases the residence time of the fluid, reduces the investment cost, reduces the maintenance cost of the equipment, and realizes the effective combination of social value and economic value.

[0037] In the above embodiment, preferably, the neutralization tank 2 of the integrated device is made of stainless steel because the pH of the influent is relatively low, generally less than 3, and the chloride ion content is relatively low.

[0038] In the above embodiment, preferably, the neutralization tank 2 is provided with a wastewater inlet 1 and a first dosing port for adding ammonia water, a first agitator 4 is provided in the neutralization tank 2, and a neutralization tank drain port 3 is provided at the bottom of the neutralization tank 2.

[0039] In this embodiment, ammonia water is added to the neutralization tank 2 through the first dosing port to adjust the pH value of the iron phosphate wastewater in the neutralization tank 2 to 9-10. Since the main cations in the iron phosphate wastewater are ammonium salts and some metal ions, adding ammonia water does not introduce new ions, so that the Ca 2+ Mg 2+ , Fe 3+ , Mn 2+ Metal ions such as Ca2+ can be precipitated to effectively remove Ca2+ from wastewater. 2+ Mg 2+ , Fe 3+ , Mn 2+The scaling of metal ions such as ions on the membrane elements and the purity of the evaporation and crystallization of the monoammonium phosphate product in the back end are affected. The traditional pretreatment system uses sodium carbonate for neutralization, and the sodium sulfate produced will mix with ammonium sulfate, affecting the purity of the subsequent crystallized salt and the recovery and reuse of waste salt, and increasing carbon dioxide emissions.

[0040] In the above embodiment, preferably, a second dosing port for adding organic sulfur or sodium sulfide is provided on the reaction tank 5, and a second agitator 6 is provided in the reaction tank.

[0041] In the above embodiment, preferably, the concentration of the organic sulfur or sodium sulfide added is 1% to 3% to ensure a better removal effect on heavy metal ions under alkaline conditions.

[0042] In this embodiment, organic sulfur or sodium sulfide is added into the reaction tank 5 through the second dosing port to precipitate heavy metal ions in the iron phosphate wastewater.

[0043] In the above embodiment, preferably, a third dosing port for adding flocculants is provided on the flocculation tank 7, and a third agitator 8 is provided in the flocculation tank 7. The flocculant in this embodiment is preferably polyaluminium ferric sulfate.

[0044] In this embodiment, since the anions in the iron phosphate wastewater are mainly SO4 2- and PO4 3- , polyaluminium ferric sulfate is added to the flocculation tank through the third dosing port to form large particles of alum, which further removes suspended matter, accelerates the sedimentation effect, saves residence time, and reduces the volume of the rear clarifier 9.

[0045] Furthermore, since polyaluminium ferric sulfate is added to the flocculation tank 7, no new anions are introduced, and cations such as aluminium and iron will flocculate and precipitate with the suspended matter, and sulfate will react with excess ammonium ions, and finally salt separation and crystallization through the nanofiltration membrane will generate ammonium sulfate, which can be sold as a fertilizer.

[0046] In the above embodiment, preferably, a clean water zone, a honeycomb inclined plate packing layer 11 and a sludge separation zone are sequentially arranged in the clarifier 9 from top to bottom; wherein, a serrated overflow weir is arranged at the position corresponding to the clean water zone of the clarifier 9, and a clean water outlet 12 is arranged at the outlet of the serrated overflow weir, and the clean water outlet 12 transports the treated clean water to other equipment or places through a clean water delivery pump 13; a scraper 10 is arranged in the sludge separation zone of the clarifier 9, and a sludge discharge port 15 is arranged at the bottom of the sludge separation zone of the clarifier 9, and the scraper 10 is used to transport the precipitated sludge to the sludge discharge port 15, and the sludge discharge port 15 transports the treated sludge to other equipment or places through a sludge delivery pump 16; a sludge emptying port 14 is also arranged at the position corresponding to the sludge separation zone of the clarifier 9.

[0047] In the above embodiment, preferably, the setting height of the honeycomb inclined plate packing layer 11 is 0.8-1m, and the inclination angle of the honeycomb inclined plate packing layer 11 is 60°; the spacing between the honeycomb inclined plate packing layer 11 and the serrated overflow weir is 1m, and the spacing between the honeycomb inclined plate packing layer 11 and the sludge separation zone is 2-3m.

[0048] In the above embodiment, preferably, the clarifier 9 is also provided with a fourth dosing port for adding coagulant PAM at a position corresponding to the sludge separation zone; when the sedimentation effect of the sludge does not meet the requirements, the coagulant PAM can be added to the clarifier 9 through the fourth dosing port, and the concentration of the coagulant PAM is preferably 0.1%.

[0049] In this embodiment, the alum flocs produced after adding flocculants to the flocculation tank 7 are separated from the water. When the wastewater after the flocculation tank 7 flows into the clarifier 9 from bottom to top, the supernatant enters the honeycomb inclined plate filler layer 11. The honeycomb inclined plate filler layer 11 will increase its residence time, making it easier for the sludge to aggregate and settle; the supernatant is discharged through the clean water outlet 12 after passing through the serrated overflow weir, and the treated clean water is transported to other equipment or locations through the clean water delivery pump 13; the sludge deposited at the bottom of the clarifier 9 is further concentrated with the help of the scraper 10 and discharged through the sludge discharge port 15, and the treated sludge is transported to other equipment or locations through the sludge delivery pump 16.

[0050] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may be subject to various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An integrated device for pretreatment of iron phosphate wastewater, characterized in that: It includes a pH neutralization system, a heavy metal reaction system, a flocculation sedimentation system and a clarification system which are sequentially arranged along the flow direction of the iron phosphate wastewater; The clarification system is used to separate solid from liquid in the wastewater treated by the flocculation and sedimentation system; The pH neutralization system comprises a neutralization tank (2), the heavy metal reaction system comprises a reaction tank (5), the flocculation precipitation system comprises a flocculation tank (7), and the clarification system comprises a clarifier (9); The neutralization tank (2), the reaction tank (5) and the flocculation tank (7) are arranged side by side to form a triple box, and the triple box is connected to the clarifier (9) through upper and lower baffles, so that the water treated by the flocculation tank (7) flows from bottom to top into the clarifier (9); The clarifier (9) is provided with a clear water zone, a honeycomb inclined plate filler layer (11) and a sludge separation zone in order from top to bottom; The clarifier (9) is provided with a sawtooth overflow weir at a position corresponding to the clean water zone, and a clean water outlet (12) is provided at the outlet of the sawtooth overflow weir, and the clean water outlet (12) transports the treated clean water through a clean water delivery pump (13); the clarifier (9) is provided with a sludge scraper (10) in the sludge separation zone corresponding to the clarifier (9), and a sludge discharge port (15) is provided at the bottom of the sludge separation zone corresponding to the sludge separation zone, and the sludge scraper (10) is used to transport the precipitated sludge to the sludge discharge port (15), and the sludge discharge port (15) transports the treated sludge through a sludge delivery pump (16); the clarifier (9) is also provided with a sludge emptying port (14) at a position corresponding to the sludge separation zone; The clarifier (9) is also provided with a fourth dosing port for adding a coagulant aid at a position corresponding to the sludge separation zone.

2. The integrated device according to claim 1, characterized in that: In the triple box, an upper baffle is provided between the neutralization tank (2) and the reaction tank (5), and a lower baffle is provided between the reaction tank (5) and the flocculation tank (7); The bottom end of the upper baffle plate and the top end of the lower baffle plate form a channel for waste water to flow.

3. The integrated device according to claim 1, characterized in that: The neutralization tank (2) is provided with a wastewater inlet (1) and a first dosing port for adding ammonia water, a first agitator (4) is provided in the neutralization tank (2), and a neutralization tank drain port (3) is provided at the bottom of the neutralization tank (2).

4. The integrated device according to claim 2, characterized in that: The reaction tank (5) is provided with a second dosing port for adding organic sulfur or sodium sulfide, and a second stirrer (6) is provided in the reaction tank (5).

5. The integrated device according to claim 1, characterized in that: The flocculation tank (7) is provided with a third dosing port for adding flocculants, and a third agitator (8) is provided in the flocculation tank.

6. The integrated device according to claim 5, characterized in that: The flocculant is polyaluminium ferric sulfate.

7. The integrated device according to claim 1, characterized in that: The height of the honeycomb inclined plate filling layer (11) is 0.8-1 m, and the inclination angle of the honeycomb inclined plate filling layer (11) is 60°; The distance between the honeycomb inclined plate filler layer (11) and the sawtooth overflow weir is 1 m, and the distance between the honeycomb inclined plate filler layer (11) and the sludge separation zone is 2-3 m.

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