Phosphogypsum purification treatment system

Abstract

The utility model relates to a phosphogypsum purification treatment system which comprises a vacuum belt filter, a connecting guide pipe, a first water inlet pipe, a second water inlet pipe, a first water outlet pipe and a second water outlet pipe. The first filtering area is provided with a solid feeding hole, a first liquid feeding hole and a first liquid discharging hole, and the first liquid discharging hole is communicated with the first water outlet pipe; the second filtering area is provided with a second liquid feeding hole and a second liquid discharging hole, the second liquid feeding hole is communicated with the first water inlet pipe, and the second liquid discharging hole is communicated with the second water outlet pipe; the third filtering area is provided with a third liquid feeding hole, a third liquid discharging hole and a solid discharging hole, and the third liquid feeding hole is communicated with the second water inlet pipe; and the first liquid feeding hole is communicated with the third liquid discharging hole through a connecting guide pipe. The ardealite is cleaned by the vacuum belt filter in a partitioned and graded manner, the purification effect is excellent, the equipment is simple and easy to operate, and the production cost is low.

Description

Technical Field

[0001] The present application relates to the technical field of solid waste purification and treatment, and in particular to a phosphogypsum purification and treatment system. Background Art

[0002] With the rapid development of the phosphate fertilizer industry, phosphogypsum emissions have increased dramatically. Currently, the comprehensive utilization rate of phosphogypsum is low, and the primary method of disposal is storage, which not only occupies a large amount of land but also poses environmental pollution risks. Untreated phosphogypsum contains numerous hazardous substances, such as phosphorus impurities, fluorine impurities, and organic matter. Soluble phosphorus and fluorine, when exposed to the natural environment, can easily enter soil, groundwater, and rivers, causing soil and water pollution. Therefore, effectively removing impurities from phosphogypsum is a prerequisite for its effective and harmless use. Furthermore, phosphogypsum also contains a large amount of valuable phosphoric acid. Recovering phosphoric acid from phosphogypsum waste would further reduce production costs and achieve significant economic benefits.

[0003] Currently, technologies for harmless treatment of phosphogypsum include chemical treatments. The basic principle of chemical treatment is to react certain cations with soluble phosphorus and fluorine to form insoluble compounds, thereby achieving passivation. However, the raw materials used are all chemical products, resulting in high material costs, and the treated gypsum is not effectively utilized. Patent application number 200820174900.8 discloses a method for removing P2O5 using water, but this method is not ideal and cannot meet purification requirements. Patent application number 201110188922.6 discloses a method for harmless treatment of phosphogypsum through steps such as cleaning, neutralization, dehydration, calcination, and packaging. This technical solution requires high equipment investment and fails to achieve an effective combination of phosphogypsum recycling and harmless treatment. Utility Model Content

[0004] The embodiment of the present application provides a phosphogypsum purification system to solve the problems of high cost and poor harmless treatment effect of phosphogypsum purification in related technologies.

[0005] The technical solutions provided in this application are as follows:

[0006] A phosphogypsum purification system includes a vacuum belt filter, a connecting conduit, a first water inlet pipe, a second water inlet pipe, a first water outlet pipe, and a second water outlet pipe. The vacuum belt filter includes a first filter zone, a second filter zone, and a third filter zone connected in sequence. The first filter zone is provided with a solid feed port, a first liquid feed port, and a first liquid outlet port. The first liquid outlet port is connected to the first water outlet pipe.

[0007] The second filtration zone is provided with a second liquid feed port and a second liquid discharge port, the second liquid feed port is connected to the first water inlet pipe, and the second liquid discharge port is connected to the second water outlet pipe;

[0008] The third filtration zone is provided with a third liquid feed port, a third liquid discharge port and a solid discharge port, and the third liquid feed port is connected to the second water inlet pipe;

[0009] The first liquid feed port and the third liquid discharge port are communicated with each other through the connecting conduit.

[0010] In some embodiments, a first slurrying tank, a cyclone and a second slurrying tank are further included. The cyclone is arranged between the first slurrying tank and the second slurrying tank, and is respectively connected to the first slurrying tank and the second slurrying tank. The second slurrying tank is arranged between the cyclone and the vacuum belt filter, and is connected to the solid feed port.

[0011] In some embodiments, a water supply system is further included, and the water supply system is connected to the first pulping tank and the second pulping tank respectively.

[0012] In some embodiments, a third water outlet pipe is further included, and the third water outlet pipe is connected to the cyclone.

[0013] In some embodiments, a first conveying system is further included, and the first conveying system is connected to the third water outlet pipe.

[0014] In some embodiments, a heater is further included, and the heater is connected to the second liquid feed port through the first water inlet pipe.

[0015] In some embodiments, a magnetizing device is further included, and the magnetizing device is disposed between the first water inlet pipe and the heater.

[0016] In some embodiments, a heat exchanger is further included, and the heat exchanger is connected to the second liquid outlet through the second water outlet pipe.

[0017] In some embodiments, the heat exchanger is in communication with the first water outlet pipe;

[0018] The heat exchanger is communicated with the third liquid feed port through the second water inlet pipe.

[0019] In some embodiments, a drum screen and a blower are further included, wherein the drum screen is connected to the solid discharge port, and the blower outlet points to the inner cavity of the drum screen.

[0020] The beneficial effects of the technical solution provided by the present application include: the embodiment of the present application provides a phosphogypsum purification system, in which phosphogypsum is cleaned in zones and grades through a vacuum belt filter, and the water inlet and outlet systems of each filter zone are independently set, effectively improving the purification efficiency of phosphogypsum. After treatment, the calcium sulfate dihydrate content of the phosphogypsum can reach more than 90%, the pH value can reach more than 6, and the water-soluble phosphorus pentoxide is less than 0.1%, fully meeting the requirements for harmless treatment of phosphogypsum;

[0021] The filtrate produced in the third filter zone of the vacuum belt filter is highly clean and can be recycled back to the first filter zone for use, effectively reducing production costs. No additional additives are used, and no pollutants are discharged during the entire process. It is energy-saving and environmentally friendly, with good economic and environmental benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0023] Figure 1 This is a schematic diagram of the structure of the phosphogypsum purification system provided in an embodiment of the present application.

[0024] In the figure: 1. Vacuum belt filter; 110. First filter zone; 111. Solid feed port; 112. First liquid feed port; 113. First liquid discharge port; 120. Second filter zone; 121. Second liquid feed port; 122. Second liquid discharge port; 130. Third filter zone; 131. Third liquid feed port; 132. Third liquid discharge port; 133. Solid discharge port; 2. Connecting conduit; 3. First water inlet pipe; 4. Second water inlet pipe; 5. First water outlet pipe; 6. Second water outlet pipe; 7. First pulping tank; 8. Cyclone; 9. Second pulping tank; 10. Water supply system; 11. Third water outlet pipe; 12. First conveying system; 13. Heater; 14. Magnetization device; 15. Heat exchanger; 16. Second conveying system; 17. Drum screen; 18. Blower. DETAILED DESCRIPTION

[0025] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0026] The embodiment of the present application provides a phosphogypsum purification system, which can solve the problems of high phosphogypsum purification cost and poor harmless treatment effect in related technologies.

[0027] like Figure 1 As shown, the phosphogypsum purification system provided in an embodiment of the present application includes a vacuum belt filter 1, a connecting conduit 2, a first water inlet pipe 3, a second water inlet pipe 4, a first water outlet pipe 5, and a second water outlet pipe 6. The vacuum belt filter 1 includes a first filter area 110, a second filter area 120, and a third filter area 130 connected in sequence. The first filter area 110 is provided with a solid feed port 111, a first liquid feed port 112, and a first liquid discharge port 113. The first liquid discharge port 113 is connected to the first water outlet pipe 5;

[0028] The second filtering area 120 is provided with a second liquid feed port 121 and a second liquid discharge port 122 , the second liquid feed port 121 is connected to the first water inlet pipe 3 , and the second liquid discharge port 122 is connected to the second water outlet pipe 6 ;

[0029] The third filtration zone 130 is provided with a third liquid feed port 131 , a third liquid discharge port 132 and a solid discharge port 133 , and the third liquid feed port 131 is connected to the second water inlet pipe 4 ;

[0030] The first liquid feed port 112 and the third liquid discharge port 132 are connected via the connecting conduit 2 .

[0031] The phosphogypsum is cleaned in different zones and grades by a vacuum belt filter 1. The water inlet and outlet systems of each filter zone are independently set, which effectively improves the purification efficiency of the phosphogypsum. After treatment, the calcium sulfate dihydrate content of the phosphogypsum can reach more than 90%, the pH value can reach more than 6, and the water-soluble phosphorus pentoxide is less than 0.1%, fully meeting the requirements for harmless treatment of phosphogypsum.

[0032] The filtrate produced in the third filter zone 130 in the vacuum belt filter 1 is highly clean and can be recycled back to the first filter zone 110 for use, effectively reducing production costs, without the use of additional additives, and without pollutants being discharged during the entire process. It is energy-saving and environmentally friendly, and has good economic and environmental benefits.

[0033] In this application, in order to achieve higher economic benefits and phosphogypsum purification effects, the washing solvent used in the purification of phosphogypsum is water.

[0034] It should be noted that the phosphogypsum purification system provided in this application has high universality and is suitable for the purification of most solid wastes, including but not limited to the purification of phosphogypsum, the purification of red mud, etc.

[0035] In some embodiments, the phosphogypsum purification system also includes a first slurrying tank 7, a cyclone 8 and a second slurrying tank 9. The cyclone 8 is arranged between the first slurrying tank 7 and the second slurrying tank 9, and is respectively connected to the first slurrying tank 7 and the second slurrying tank 9. The second slurrying tank 9 is arranged between the cyclone 8 and the vacuum belt filter 1, and is connected to the solid feed port 111.

[0036] The first slurrying tank 7 can be directly connected to the upstream production line, so that the solid waste phosphogypsum generated on the production line can be discharged into the first slurrying tank 7 through the filter press. The first slurrying tank 7 is mainly used to mix the solid phosphogypsum with water to form a slurry, thereby achieving full dissolution of soluble impurities such as phosphorus, fluorine, and sulfuric acid in the phosphogypsum, and purifying and separating organic impurities through the cyclone 8. The wastewater generated in the cyclone 8 contains a large amount of impurities and effectively recoverable components, which can be returned to the recovery process, such as the mineral processing process, for subsequent treatment, which is beneficial to improving the recovery and utilization rate of phosphogypsum, reducing the discharge of pollutants, and achieving greater economic and environmental benefits.

[0037] The phosphogypsum is subjected to the first-stage cleaning by the cyclone 8, and most of the impurities have been separated. In order to further improve the harmless purification effect of the phosphogypsum, the phosphogypsum that has completed the first-stage cleaning is slurried in the second slurry tank 9 and then passed into the first filtering zone 110 of the vacuum belt filter 1 for the second-stage cleaning.

[0038] In some embodiments, the phosphogypsum purification system further includes a water supply system 10 , and the water supply system 10 is connected to the first slurry making tank 7 and the second slurry making tank 9 respectively.

[0039] The water supply system 10 is used to provide water to the first slurry making tank 7 and the second slurry making tank 9, in order to form a mixed slurry with solid phosphogypsum so that soluble impurities in the phosphogypsum can be dissolved in water, thereby achieving purification of the phosphogypsum.

[0040] Specifically, the water supply system may adopt a commonly used water supply system in the art, which is not particularly limited herein. For example, the water supply system may include a circulating water pump, a conduit, a water storage tank, and the like.

[0041] In a preferred embodiment, the filtrate produced by the third filtration zone 130 is used to replace the water supply system 10, that is, the third liquid discharge port 132 of the third filtration zone 130 is connected to the first pulping tank 7 and the second pulping tank 9 respectively, so that the filtrate with higher cleanliness produced by the third filtration zone 130 can be circulated back to the first pulping tank 7 and the second pulping tank 9 for use. This design can significantly reduce the water consumption of the enterprise, thereby achieving lower-cost production.

[0042] In some embodiments, the phosphogypsum purification system further includes a third water outlet pipe 11 , and the third water outlet pipe 11 is connected to the cyclone 8 .

[0043] The third water outlet pipe 11 is used to discharge the filtrate containing a large amount of impurities separated in the cyclone 8 out of the phosphogypsum purification system, thereby improving the subsequent purification effect of the phosphogypsum.

[0044] In some embodiments, the phosphogypsum purification system further includes a first conveying system 12 , and the first conveying system 12 is connected to the third water outlet pipe 11 .

[0045] The first conveying system 12 is used to convey the recyclable filtrate discharged from the third outlet pipe 11 to the wastewater treatment process, such as the mineral processing process, thereby avoiding the direct discharge of wastewater generated by the purification system into the environment. It is green and pollution-free, and improves the recovery rate of phosphogypsum.

[0046] In some embodiments, the phosphogypsum purification system further includes a heater 13 , and the heater 13 is connected to the second liquid feed port 121 through the first water inlet pipe 3 .

[0047] The heater 13 is used to heat the water entering the second filtering zone 120 to increase the dissolution rate of soluble impurities in the phosphogypsum and further improve the harmless treatment effect of the phosphogypsum.

[0048] In a preferred embodiment, the water entering the second filtration zone 120 is heated to above 90° C. by the heater 13 and is then passed through a washer (not shown) to perform a third-stage cleaning of the phosphogypsum.

[0049] Specifically, the heater 13 may include but is not limited to a boiler. In a preferred embodiment, waste heat generated by upstream phosphoric acid production may be used to heat the boiler, thereby effectively reducing the production cost of the enterprise and being energy-saving and environmentally friendly.

[0050] In some embodiments, the phosphogypsum purification system further includes a magnetizing device 14 , which is disposed between the first water inlet pipe 3 and the heater 13 .

[0051] The magnetizing device 14 is used to magnetize the clean water entering the second filtration zone 120 into magnetized water. Using the ultra-high-intensity magnetic field generated by the magnet, the magnetizing device 14 alters the physical structure of the minerals in the water without altering the water's original chemical composition. This breaks down the previously chain-like macromolecules into individual small molecules, causing the dipole moment of the water molecules to shift. This allows the positive and negative ions of soluble impurities such as phosphoric acid in the phosphogypsum to be surrounded by individual water molecules, disrupting their adhesion and aggregation. Furthermore, the increased dipole moment of the water molecules increases the attraction between the positive and negative ions and the soluble impurities, making it easier for the soluble impurities adhering to the phosphogypsum to be separated and dissolved in the water for removal, thus improving the purification of the phosphogypsum.

[0052] In conjunction with the use of the heater 13, the hot water close to the boiling point enhances the activity of the magnetized water, thereby achieving a better purification effect.

[0053] In some embodiments, the phosphogypsum purification system further includes a heat exchanger 15 , and the heat exchanger 15 is connected to the second liquid outlet 122 through the second water outlet pipe 6 .

[0054] Since the temperature of the filtrate generated in the second filtration zone 120 is still relatively high, in order to improve the economic benefits of the enterprise, the heat exchanger 15 is used to recover part of the waste heat of the filtrate generated in the second filtration zone 120 .

[0055] In some embodiments, the heat exchanger 15 is connected to the third liquid feed port 131 through the second water inlet pipe 4 .

[0056] The heat exchanger 15 absorbs the heat of the filtrate generated by the second filtering zone 120 and can heat the water entering the third filtering zone 130, which is beneficial to increasing the dissolution rate of soluble impurities in the phosphogypsum and further improving the harmless treatment effect of the phosphogypsum.

[0057] In a preferred embodiment, the water entering the third filtering zone 130 is heated to above 50° C. by the heat exchanger 15 and passes through a washer (not shown) to perform a fourth-stage cleaning of the phosphogypsum.

[0058] In some embodiments, the phosphogypsum purification system further includes a second conveying system 16 , which is connected to the heat exchanger 15 and the first water outlet pipe 5 , respectively.

[0059] Since the filtrate produced in the first filtration zone 110 and the second filtration zone 120 still contains a large amount of recyclable material - phosphoric acid, in order to reduce the company's production costs, improve economic benefits, and avoid the discharge of pollutants, the second conveying system 16 is used to convey the filtrate produced in the first filtration zone 110 and the second filtration zone 120 to other sections, such as the phosphoric acid recovery process.

[0060] In some embodiments, the phosphogypsum purification system further includes a drum screen 17 and a blower 18 . The drum screen 17 is connected to the solid discharge port 133 , and the air outlet of the blower 18 points to the inner cavity of the drum screen 17 .

[0061] Since the phosphogypsum after filtration and purification by the vacuum belt filter 1 still has a moisture content of about 20% and a residual temperature of 50-70°C, in order to further reduce the moisture content and temperature of the phosphogypsum, the drum screen 17 and the blower 18 are used to effectively and quickly reduce the moisture content of the phosphogypsum to 5-10%, meeting subsequent storage requirements.

[0062] After the treatment of the utility model, the organic impurities in the phosphogypsum are separated in the cyclone, and the water-soluble substances are filtered by the cyclone and the vacuum belt filter and then transferred to the water to be separated out. The harmful substances in the phosphogypsum obtained after filtration are greatly reduced, and no pollution is caused to the environment during the storage process.

[0063] In the description of this application, it should be noted that the terms "upper" and "lower" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply 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 a limitation on this application. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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 an indirect connection through an intermediate medium, or it can be internal communication between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0064] It should be noted that, in this application, relational terms such as "first" and "second" are used solely to distinguish one entity or operation from another, and do not necessarily require or imply any actual relationship or order between these entities or operations. Furthermore, the terms "comprise," "include," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or device comprising a set of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. Without further limitation, an element defined by the phrase "comprising a..." does not preclude the presence of additional identical elements in the process, method, article, or device comprising the recited element. The foregoing description is intended only to provide specific embodiments of the present application, intended to enable those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to be accorded the broadest scope consistent with the principles and novel features of the present application.

Claims

1. A phosphogypsum purification system, characterized in that: The invention comprises a vacuum belt filter (1), a connecting conduit (2), a first water inlet pipe (3), a second water inlet pipe (4), a first water outlet pipe (5) and a second water outlet pipe (6); the vacuum belt filter (1) comprises a first filter area (110), a second filter area (120) and a third filter area (130) connected in sequence; the first filter area (110) is provided with a solid feed port (111), a first liquid feed port (112) and a first liquid outlet port (113); the first liquid outlet port (113) is connected to the first water outlet pipe (5); The second filtration zone (120) is provided with a second liquid feed port (121) and a second liquid discharge port (122), the second liquid feed port (121) is connected to the first water inlet pipe (3), and the second liquid discharge port (122) is connected to the second water outlet pipe (6); The third filtration zone (130) is provided with a third liquid feed port (131), a third liquid discharge port (132) and a solid discharge port (133), and the third liquid feed port (131) is in communication with the second water inlet pipe (4); The first liquid feed port (112) and the third liquid discharge port (132) are connected via the connecting conduit (2).

2. The phosphogypsum purification system according to claim 1, characterized in that: The invention also includes a first pulping trough (7), a cyclone (8) and a second pulping trough (9), wherein the cyclone (8) is arranged between the first pulping trough (7) and the second pulping trough (9), and is communicated with the first pulping trough (7) and the second pulping trough (9) respectively; the second pulping trough (9) is arranged between the cyclone (8) and the vacuum belt filter (1), and is communicated with the solid feed port (111).

3. The phosphogypsum purification system according to claim 2, characterized in that: It also includes a water supply system (10), which is communicated with the first pulping tank (7) and the second pulping tank (9) respectively.

4. The phosphogypsum purification system according to claim 3, characterized in that: It also includes a third water outlet pipe (11), and the third water outlet pipe (11) is connected to the cyclone (8).

5. The phosphogypsum purification system according to claim 4, characterized in that: It also includes a first conveying system (12), wherein the first conveying system (12) is in communication with the third water outlet pipe (11).

6. The phosphogypsum purification system according to claim 1, characterized in that: The invention also comprises a heater (13), wherein the heater (13) is connected to the second liquid feed port (121) through the first water inlet pipe (3).

7. The phosphogypsum purification system according to claim 6, characterized in that: It also includes a magnetizing device (14), which is arranged between the first water inlet pipe (3) and the heater (13).

8. The phosphogypsum purification system according to claim 1, characterized in that: It also includes a heat exchanger (15), and the heat exchanger (15) is connected to the second liquid discharge port (122) through the second water outlet pipe (6).

9. The phosphogypsum purification system according to claim 8, characterized in that: It also includes a second conveying system (16), wherein the second conveying system (16) is communicated with the heat exchanger (15) and the first water outlet pipe (5) respectively; The heat exchanger (15) is connected to the third liquid feed port (131) via the second water inlet pipe (4).

10. The phosphogypsum purification system according to claim 1, characterized in that: It also includes a drum screen (17) and a blower (18), wherein the drum screen (17) is communicated with the solid material discharge port (133), and the air outlet of the blower (18) points to the inner cavity of the drum screen (17).

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