CN109942112A - A kind of recycling and processing equipment of ardealite storage yard percolate and its processing method - Google Patents

Abstract

The invention provides a recycling treatment device for phosphogypsum storage yard leachate and a treatment method thereof. The treatment device includes a pretreatment system, an ultrafiltration treatment system and an RO treatment system which are connected in sequence. The method can effectively concentrate and recycle the phosphorus and fluorine resources in the leachate, the produced water can be reused for production water, reduce the cost of production water intake, the system does not produce or greatly reduces the production of sludge, and the water quality of the system is stable. The operating cost is significantly lower than the traditional method, and the system is easy to manage and operate.

Description

A kind of recycling treatment device of phosphogypsum storage yard leachate and its treatment method

technical field

The invention belongs to the technical field of waste water treatment, and in particular relates to a treatment device and method for the recycling and utilization technology of phosphogypsum storage yard leachate resources.

Background technique

Phosphogypsum is a solid waste residue produced when phosphate rock is treated with sulfuric acid in the production of phosphoric acid, and its main component is calcium sulfate. Impurities such as fluoride, free phosphoric acid, P ₂ O ₅ , and phosphate contained in phosphogypsum are the main factors that cause environmental pollution during the storage process of phosphogypsum. A large number of phosphogypsum deposits not only occupy land resources, but also pollute the atmosphere, water system and soil due to wind erosion and rain erosion. Prolonged exposure to phosphogypsum may cause death or disease in humans. In the process of phosphogypsum landfill or stacking, leachate will be produced due to the action of rainwater. The content of phosphorus and fluorine in the leachate is very high, and the pH is very low. Once infiltrated into the ground, it will not only waste a lot of phosphorus and fluorine resources, but also seriously pollute the nearby groundwater and surface water resources, which will have a very serious impact on the nearby watershed and residents' lives. If it can be effectively reused, it is of great significance to pollution prevention, economic benefits, sustainable development and other aspects.

At present, most of the processes for phosphogypsum leachate treatment choose the following methods:

Neutralization and precipitation method: use quicklime to neutralize and precipitate, and finally obtain a waste residue with calcium phosphate and calcium fluoride as the main components. The disadvantage of this method is that the high content of phosphorus and fluorine results in a large amount of quicklime required and a large amount of slag produced. Not only the cost of chemicals is high, but also in the mode of slag-based production, it seriously affects the survival and development of enterprises.

Closed recycling method: The utilization method is mixed with the sewage of the production system, and then enters the ball mill for wet grinding to make pulp, which is then reacted in the extraction tank and enters the filtration system. The filtrate of the gypsum yard is closed and recycled. The disadvantage of this method is that the impurity content in the phosphogypsum is continuously accumulated, the effective mass concentration of the pulp will be greatly reduced, and it cannot be effectively used for long-term continuous operation, and the filtered phosphogypsum still has pollution. question.

SUMMARY OF THE INVENTION

The object of the present invention is to overcome the above-mentioned shortcomings and provide a method that can effectively concentrate and recycle the phosphorus and fluorine resources in the leachate, and the produced water can be reused for production water, reducing the cost of production water, and the system does not generate or greatly reduce The production of sludge, the stable reuse of the water quality of the system, the operating cost is greatly lower than the traditional method, the system is easy to manage and operate, and can fully realize automatic control of a phosphogypsum storage yard leachate recycling treatment device and its Approach.

Purpose of the present invention and solving its main technical problem are to adopt the following methods to realize:

A phosphogypsum storage yard leachate recycling treatment device includes a pretreatment system, an ultrafiltration treatment system, and an RO treatment system connected in sequence; the pretreatment system includes a coagulation reaction pool and an intermediate pool connected in sequence; the The ultrafiltration treatment system includes a high-efficiency filter device, a heat exchange device, a self-cleaning filter device, an ultrafiltration device, and an ultrafiltration pool connected in sequence; the RO treatment system includes a security filter device one connected in sequence, a first-level RO device, Primary RO production pool, primary RO concentrated pool, security filter device 2, secondary RO device, secondary RO production pool, secondary RO concentrated pool, desalination device;

The intermediate pool in the pretreatment system enters the high-efficiency filtration device of the ultrafiltration treatment system through the ultrafiltration lifting pump;

The ultrafiltration pool enters the security filter device 1 through the first-level RO inlet pump, and the effluent of the security filter device 1 enters the first-level RO device through high-pressure pump-pressurization; the concentrated water of the first-level RO device is reused to phosphoric acid. During the production process, the produced water of the first-stage RO device enters the first-stage RO production pool, and the pH of the produced water is adjusted to be controlled between 7-8; the first-stage RO production pool enters the first-stage RO water pump through the second-stage RO water inlet pump. Security filter device 2, the effluent of security filter device 2 is pressurized by the high-pressure pump 2 and enters the secondary RO device for treatment and then enters the secondary RO production pool; the concentrated water of the secondary RO device is returned to the ultrafiltration tank for reprocessing, so the The produced water of the secondary RO device is reused after entering the desalination device for treatment;

A recycling treatment device for phosphogypsum storage yard leachate further includes a regeneration water system, the regeneration water system includes a regeneration water collection tank for collecting backwash water of a high-efficiency filter device, backwash water of an ultrafiltration device, and concentrated water, The regenerated water collection tank enters the coagulation reaction tank through the regenerated water lift pump for further treatment.

In the above-mentioned recycling treatment device for phosphogypsum stockyard leachate, the pretreatment system further includes a sludge treatment device, which collects the sludge in the coagulation reaction tank and transports it to the outside after treatment.

In the above-mentioned recycling treatment device for phosphogypsum stockyard leachate, the coagulation reaction tank is provided with a submersible mixer at the bottom of the pool near the pool wall for continuous stirring.

The above-mentioned recycling treatment device for phosphogypsum stockyard leachate, wherein the coagulation reaction tank is coagulated by adding specific coagulants and flocculants that can have better treatment effects under the condition of PH<3. The agent is modified tan polyaluminum chloride, and the flocculant is cationic polyacrylamide with a molecular weight of about 1000. The coagulant and flocculant pass through the groups with positive (negative) electricity and the water with negative (positive) ) Some particles or particles that are electrically difficult to separate are close to each other, reduce their potential, make them in an unstable state, and use their polymerization properties to concentrate these particles, so that fine suspensions or colloidal particles in the acid leachate can be adsorbed and combined with each other. settle into larger particles.

The above-mentioned recycling treatment device for phosphogypsum storage yard leachate, wherein the ultrafiltration system further retains fine particles, colloids, bacteria, heat sources in the acid leachate under the action of pressure and microporous membranes and organic matter to ensure the water quality entering the first-level RO device; the filter material of the high-efficiency filter device in the ultrafiltration system is acid-resistant anthracite, nut shell filter material, foam filter beads, granular activated carbon, fiber filter material, etc.; The ultrafiltration membrane of the ultrafiltration device in the ultrafiltration system is made of cellulose acetate or nitrocellulose or a mixture of the two, which are both resistant to acid at pH<3, or polysulfone membrane, polysulfone amide membrane and polyacrylonitrile membrane, etc. .

The above-mentioned recycling treatment device for phosphogypsum storage yard leachate, wherein the primary RO device is pressurized by a high-pressure pump, and the raw water is concentrated and reused in the production process, and the produced water enters the primary RO production pool By adjusting the pH between 7-8, it enters the secondary RO device for treatment, the concentrated water of the secondary RO device is returned to the ultrafiltration tank for further treatment, and the produced water enters the desalination device for treatment and reuse.

The above-mentioned recycling treatment device for phosphogypsum storage yard leachate, wherein: the RO membranes of the primary RO device and the secondary RO device are special acid-resistant and anti-pollution reverse osmosis membranes; the primary RO is operated The pressure is between 1.3-2.2MPa, and the operating pressure of the secondary RO is between 0.3-1.0MPa.

A method for reusing phosphogypsum storage yard leachate of the present invention comprises the following steps:

(1) Pretreatment: The pretreatment of the phosphogypsum storage yard leachate is to make the fine suspended solids or colloidal particles in the acid leachate adsorb and combine with each other to precipitate larger particles by adding a coagulant and a flocculant to react. , the supernatant liquid enters the intermediate tank, the sludge enters the sludge treatment device and is transported out after treatment, the coagulant is modified tan polyaluminum chloride, and the flocculant is cationic polyacrylamide with a molecular weight of about 1000;

(2) Ultrafiltration treatment: it is discharged into the intermediate water tank, lifted by an ultrafiltration lift pump, and added with cationic polyacrylamide, sodium hypochlorite or isothiazoline and other bactericides, and then sent to a high-efficiency filtration device to remove suspended solids, organic matter, bacteria, and reduce turbidity, etc. After the indicator, it enters the heat exchange device for heat exchange, and then the turbidity is further reduced by the self-cleaning filter device to meet the water quality requirements of the ultrafiltration process; the self-cleaning filter device intercepts fine particulate matter to prevent the ultrafiltration membrane from being blocked or scratched by large particulate matter. The effluent from the self-cleaning filtration device enters the ultrafiltration membrane to remove SS, colloid and most of the bacteria. The turbidity of the ultrafiltration effluent is less than 0.2NTU, and the produced water is collected to the ultrafiltration tank after the SDI is less than 3;

(3) RO treatment: The clean water of the ultrafiltration production tank is lifted by the first-stage RO inlet pump and then added with phosphorus-containing small molecule or organic polymer linear polymer or dendrimer scale inhibitor and sodium bisulfite or sulfur Sodium sulfate and other reducing agents pass through the security filter device 1 and the high-pressure pump in turn, and then enter the primary RO device for concentration; the concentrated water of the primary RO device is recycled; the fresh water of the primary RO device enters the primary RO production pool and then adjusts the pH after After being upgraded by the secondary RO, the anti-scaling agent is added and passed through the security filter device 2 and the high-pressure pump 2 in turn, and then enters the secondary RO device for desalination. Reuse after treatment in desalination device;

(4) Reclaimed water treatment: The high-efficiency filter backwash water, ultrafiltration backwash water and concentrated water enter the reclaimed water collection tank and are lifted by the reclaimed water lift pump into the coagulation reaction tank for further treatment.

Compared with the prior art, the present invention has obvious advantages and beneficial effects. It can be seen from the above technical solutions that the present invention has the following advantages: the leachate of the phosphogypsum storage yard is pretreated to ensure the stability of water quality; Concentrate to meet the requirements of production and reuse, effectively recover phosphorus and fluorine resources, and avoid pollution; the leachate has strong acidity, and by adjusting the pH to enter the secondary RO treatment, it can effectively further remove the phosphorus in the primary RO water. The fluorine content can also produce desalinated water that meets the needs of production, which improves the utilization rate of water and avoids secondary pollution; the ultrafiltration device and RO treatment device are fully automatic control equipment, which is convenient for operation and maintenance; the entire treatment system occupies The land area is small, the investment is low, and the operating cost is low; it can ensure efficient and stable water output.

Description of drawings

Fig. 1 is the process flow diagram of the present invention;

Detailed ways

The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings.

As shown in FIG. 1, the above-mentioned recycling treatment device for phosphogypsum storage yard leachate includes a pretreatment system, an ultrafiltration treatment system, an RO treatment system, and a reclaimed water system; the pretreatment system includes a coagulation system connected in sequence. Reaction tank and intermediate water tank; the ultrafiltration treatment system includes a high-efficiency filter device, a heat exchange device, a self-cleaning filter device, an ultrafiltration device, and an ultrafiltration tank connected in sequence; the RO treatment system includes a security filter connected in sequence Device 1, primary RO device, primary RO production pool, security filter device 2, secondary RO device, secondary RO production pool, desalination device; the regenerated water system includes a recycled water collection tank; the pretreatment The system also includes a sludge treatment unit separately.

The coagulation reaction tank is provided with a submersible mixer for continuous stirring; the sludge in the coagulation reaction tank enters the sludge treatment device for processing and is transported out, and the intermediate pool in the pretreatment system is lifted by ultrafiltration The pump enters the high-efficiency filtration device of the ultrafiltration treatment system.

The ultrafiltration pool enters the security filter device 1 through the primary RO inlet pump, and the effluent of the security filter device 1 enters the primary RO device through the high pressure pump 1.

The concentrated water of the first-stage RO device is reused in the phosphoric acid production process, and the produced water of the first-stage RO device enters the first-stage RO production pool, and the pH of the produced water is adjusted and controlled between 7-8.

The first-stage RO production pool enters the security filter device 2 through the secondary RO inlet pump, and the effluent of the security filter device 2 is pressurized by the high-pressure pump 2 and enters the secondary RO device for processing and then enters the secondary RO production pool.

The concentrated water of the secondary RO device is returned to the ultrafiltration tank for reprocessing, and the produced water of the secondary RO device is treated and reused after entering the desalination device.

The regenerated water collection tank of the regenerated water system collects the backwash water of the high-efficiency filter device, the backwash water of the ultrafiltration device and the concentrated water, and then enters the coagulation reaction tank through the regenerated water lift pump for further treatment.

In the coagulation reaction tank, by adding a coagulant and a flocculant, the fine suspended solids or colloidal particles in the acid leachate are adsorbed and combined with each other to form larger particles and precipitate. The ultrafiltration system further intercepts the fine particles, colloids, bacteria, heat sources and organic matter in the acid leachate under the action of pressure and microporous membrane to ensure the water quality entering the primary RO device. The first-level RO device is processed by high pressure pump, and the raw water is concentrated and reused in the production process, and the produced water enters the first-level RO production pool and enters the second-level RO device for processing by adjusting the pH between 7-8. The concentrated water of the stage RO device is returned to the ultrafiltration tank for further treatment, and the produced water enters the desalination device for treatment and reuse. The coagulant and flocculant of the coagulation reaction tank are special pharmaceuticals with good effect under the condition of PH of 1-3. The RO membranes of the primary RO device and the secondary RO device are all specially made acid-resistant and anti-pollution reverse osmosis membranes.

As shown in Figure 1, a method for recycling phosphogypsum storage yard leachate is the pretreatment of phosphogypsum storage yard leachate by adding coagulant and flocculant to react with fine suspended solids or particles in the acid leachate. The colloidal particles are adsorbed and combined with each other to form larger particles that settle down, the supernatant liquid enters the intermediate pool, and the sludge enters the sludge treatment device for processing and then transported out.

After being discharged into the intermediate pool, the flocculants and bactericides are added to the high-efficiency filtration device to remove suspended solids, organic matter, bacteria, and turbidity and other indicators, and then enter the heat exchange device for heat exchange, and then pass through the self-cleaning filter device. Further reduce the turbidity to meet the water quality requirements of the ultrafiltration process. The self-cleaning filter device intercepts fine particulate matter to prevent the ultrafiltration membrane from being blocked or scratched by large particulate matter; the effluent from the self-cleaning filter device enters the ultrafiltration membrane to remove SS, colloids and most bacteria, and the ultrafiltration effluent has a turbidity <0.2NTU, After SDI<3, the produced water is collected into the ultrafiltration tank; the clean water of the ultrafiltration production tank is lifted by the first-stage RO inlet pump, and then the antiscalants and reducing agents are added to the first-stage RO device through the security filter device 1 and the high-pressure pump 1. concentrate. The concentrated water of the primary RO unit is recycled. The fresh water from the primary RO unit enters the primary RO production pool, and then after adjusting the pH, it is elevated by the secondary RO, and then the scale inhibitor is added to the secondary RO unit for desalination. The concentrated water is returned to the ultrafiltration production tank for reprocessing, and the fresh water from the secondary RO unit enters the desalination unit for treatment and reuse;

The high-efficiency filter backwash water, ultrafiltration backwash water and concentrated water enter the regenerated water collection tank and are lifted by the regenerated water lift pump into the coagulation reaction tank for further treatment.

The main control points of this treatment method are the dosage of coagulants and flocculants in the pretreatment system, the pressure and water production rate of the RO treatment system when the water quality changes, and the PH control of the primary RO production pool: 1. During the flood season, the raw water When the suspended solids rise sharply (>5000mg/L), it is necessary to adjust the dosage of coagulants and flocculants online to ensure the clarification of the effluent quality; in the dry season, the quality of the raw water is in good condition, and the dosing can be reduced or stopped; 2. During the flood season When entering the RO system, the phosphorus and fluorine content in the water is low. When entering the RO system, the pressure and concentrated water flow need to be adjusted to ensure the water production rate and concentration effect. The primary RO pressure is between 1.3-2.2MPa, and the secondary RO pressure is between 0.3- 1.0MPa; 3. During the dry season, the pH of the raw water is low, and the amount of liquid alkali added to the primary RO production tank should be increased to ensure that the pH entering the secondary RO treatment system is between 7-8.

Incoming and outgoing water quality table

index pH Total phosphorus mg/L Fluoride mg/L ConductivityμS/cm water intake 1 to 3 ≤4000 ≤600 ≤9000 out of water 7～8 ≤0.5 ≤10 ≤60

The above are only preferred embodiments of the present invention, and do not limit the present invention in any form. Any simple modifications made to the above embodiments according to the technical essence of the present invention without departing from the technical solution content of the present invention, Equivalent changes and modifications still fall within the scope of the technical solutions of the present invention.

Claims (7)

1. a kind of recycling and processing equipment of ardealite storage yard percolate, which is characterized in that including sequentially connected pretreatment system, Hyperfiltration treatment system, RO processing system；The pretreatment system includes sequentially connected coagulation reaction tank, intermediate pool；Institute The hyperfiltration treatment system stated include sequentially connected effective filter, heat-exchanger rig, self-cleaning filter device, ultrafiltration apparatus, Ultrafiltration pond；The RO processing system includes sequentially connected security personnel's filter device one, level-one RO device, level-one RO production water Pond, level-one RO concentrated water pond, cartridge filter device two, second level RO device, second level RO produce pond, second level RO concentrated water pond, desalted water Device；

Intermediate pool in the pretreatment system enters the effective filter of hyperfiltration treatment system by ultrafiltration elevator pump In；

The ultrafiltration pond enters security personnel's filter device one by level-one RO intake pump, and the water outlet of security personnel's filter device one passes through The pressurization of high-pressure pump one enters level-one RO device；The NF concentrated water reuse of the level-one RO device is described into production process of phosphoric acid The production water of level-one RO device enters level-one RO and produces pond, adjusts the PH for producing water, controls between 7-8；The level-one RO produces water Pond enters security personnel's filter device two by second level RO intake pump, and the water outlet of security personnel's filter device two is entered by the pressurization of high-pressure pump two Enter second level RO after the processing of second level RO device and produces pond；The concentrate recirculation of the second level RO device to ultrafiltration pond is reprocessed, The production water of the second level RO device enters reuse after removal bitter and fishiness processing；

A kind of recycling and processing equipment of ardealite storage yard percolate further includes regeneration water system, the regeneration water system It is described for collecting the backwash water of effective filter and the backwash water and concentrated water of ultrafiltration apparatus including recycled water collecting pit Recycled water collecting pit by recycled water elevator pump enter coagulation reaction tank reprocessing.

2. a kind of recycling and processing equipment of ardealite storage yard percolate according to claim 1, which is characterized in that described Pretreatment system further includes sludge treatment equipment, collects the sludge in coagulation reaction tank, transports outward after processing.

3. a kind of recycling and processing equipment of ardealite storage yard percolate according to claim 1, which is characterized in that described Diving mixer is provided in coagulation reaction tank to continuously stir.

4. a kind of recycling and processing equipment of ardealite storage yard percolate according to claim 1, which is characterized in that described Coagulation reaction tank can specifically have the coagulant and flocculant of preferable treatment effect by being added under the conditions of PH < 3, pass through band There are some particles for being difficult to separate for having positive negative electrical property in positive/negative electrical group and water or particle close to each other, reduces Its potential is at unstable state, and using its aggregation property these particles is concentrated, and makes tiny in acid percolate Suspended matter or colloidal particles, which adsorb mutually, to be combined into larger particles and precipitates.

5. a kind of recycling and processing equipment of ardealite storage yard percolate according to claim 1, which is characterized in that described The filtering material of effective filter selects acidproof anthracite, shell filtrate, foam filter pearl, seed activity in ultrafiltration system Charcoal, fiber filtering；The ultrafiltration membrane of ultrafiltration apparatus is selected in PH < 3 energy acidproof acetate fiber or nitre in the ultrafiltration system Sour fiber or this both mixture be made or PS membrane, Polysulfonamide and polyacrylonitrile film.

6. a kind of recycling and processing equipment of ardealite storage yard percolate according to claim 1, which is characterized in that described The RO film of level-one RO device and second level RO device is special acidproof anti-pollution reverse osmosis membrane；The level-one RO operating pressure Between 1.3-2.2MPa, second level RO operating pressure is between 0.3-1.0MPa.

7. a kind of processing method of the recycling and processing equipment of ardealite storage yard percolate according to claim 1, feature It is, comprising the following steps:

(1) pre-process: the pretreatment of the ardealite storage yard percolate is by making acid after dosing coagulant and flocculant reaction Fine suspension or colloidal particles, which adsorb mutually, in property percolate is combined into larger particles and precipitates, and supernatant enters centre Pond, sludge are transported outward after entering sludge treatment equipment processing；

(2) it hyperfiltration treatment: is discharged into intermediate pool and is filled after the promotion of ultrafiltration elevator pump adds flocculant and fungicide to high efficiency filter Enter heat-exchanger rig heat exchange after being placed in the indexs such as oil removal, organic matter, bacterium, reduction turbidity, then passes through self-cleaning filtering Device further decreases turbidity, meets it and enters ultrafiltration technology water quality requirement；Self-cleaning filter device retains fine particle Matter avoids ultrafiltration membrane from being blocked or scratched by large particulate matter；Self-cleaning filter device water outlet enters ultrafiltration membrane, removes SS, colloid And most of bacterium, ultra-filtration water turbidity < 0.2NTU produce water behind SDI < 3 and are collected to ultrafiltration pond；

(3) RO is handled: ultrafiltration production pond clear water adds antisludging agent after being promoted by level-one RO intake pump and reducing agent passes sequentially through guarantor Enter level-one RO device after peace filter device one, high-pressure pump one to be concentrated；Level-one RO device concentrated water recycles；Level-one RO device Fresh water enter level-one RO produce pond pass through again adjust PH after through second level RO promotion after add antisludging agent pass sequentially through security personnel filter device Two, enter second level RO device after high-pressure pump two and carry out desalination, second level RO device concentrated water returns to ultrafiltration and produces pond reprocessing, second level RO Device fresh water enters reuse after removal bitter and fishiness processing；

(4) reused water processing: high efficiency particulate air filter backwash water, hyperfiltration reverse-rinsing water and concentrated water enter recycled water collecting pit and mention through recycled water It rises pump and is lifted into coagulation reaction tank reprocessing.