A phosphogypsum pretreatment device

Abstract

This invention provides a phosphogypsum pretreatment device, applied in the technical field of phosphogypsum pretreatment devices. The key technical features are: a frame, a screening mechanism, and a washing mechanism; the washing mechanism includes a housing, a perforated inner cylinder, and a first driving component; the housing is equipped with an inlet pipe and an outlet pipe, and a feeding pipe; the first driving component drives the inner cylinder to intermittently rotate forward and reverse at a first speed to agitate the phosphogypsum, achieving thorough washing and full reaction between the phosphogypsum and alkaline substances; the first driving component drives the inner cylinder to rotate at a second speed to spin-dry the phosphogypsum; a drying mechanism is used to dry the spin-dried phosphogypsum; and a pouring mechanism is used to pour the washed and neutralized phosphogypsum from the inner cylinder into the drying mechanism. The technical advantages are: initial screening, washing, neutralization, and drying are integrated into the same device, reducing equipment footprint; continuous production is achieved through the speed switching of the first driving component and the pouring mechanism, reducing manual intervention.

Description

Technical Field

[0001] This invention relates to the technical field of phosphogypsum pretreatment equipment, and in particular to a phosphogypsum pretreatment equipment. Background Technology

[0002] In the phosphorus chemical production process, phosphogypsum (mainly composed of CaSO4·2H2O) is a byproduct of the wet-process phosphoric acid production. Its large-scale stockpiling not only occupies land resources but may also cause environmental pollution due to its free acid, fluoride, heavy metals, and organic impurities. Therefore, the resource utilization of phosphogypsum has become a key research focus in the industry, especially with the increasing demand for its application in building materials (such as gypsum board and cement retarders). However, phosphogypsum has a high impurity content and unstable physicochemical properties, and must undergo pretreatment to meet the quality requirements of building material production.

[0003] In industrial production, phosphogypsum is typically pretreated. Pretreatment facilitates subsequent calcination at different temperatures and grinding to different fineness requirements for various applications. Currently, phosphogypsum pretreatment usually includes steps such as primary screening, washing, neutralization, and drying. Traditional pretreatment processes require multiple pieces of equipment to complete the process step by step (such as vibrating screens, washing tanks, neutralization reaction tanks, and dryers). Each step operates independently, resulting in large equipment footprint, high energy consumption, and frequent manual intervention, making continuous production difficult and leading to low efficiency in phosphogypsum pretreatment. Summary of the Invention

[0004] The purpose of this invention is to provide a phosphogypsum pretreatment device, which has the advantages of integrating primary screening, washing, neutralization and drying, with a high degree of automation, thereby improving the pretreatment efficiency of phosphogypsum.

[0005] To achieve the above and other related objectives, the present invention provides the following technical solution:

[0006] A phosphogypsum pretreatment apparatus includes a frame;

[0007] A screening mechanism is used to screen phosphogypsum raw materials;

[0008] A washing mechanism is provided for washing and neutralizing sieved phosphogypsum. The washing mechanism includes a housing hinged to a frame, a perforated inner cylinder rotatably connected to the housing, and a first driving component mounted on the housing for rotating the perforated inner cylinder. The housing is equipped with an inlet pipe and an outlet pipe, and a feeding pipe for adding alkaline substances into the housing. The first driving component drives the perforated inner cylinder to intermittently rotate forward and reverse at a first rotational speed to agitate the phosphogypsum, ensuring thorough rinsing and reaction between the phosphogypsum and the alkaline substances. The first driving component also drives the inner cylinder to rotate at a second rotational speed to remove excess water from the phosphogypsum.

[0009] A drying mechanism for drying phosphogypsum that has been dehydrated;

[0010] A pouring mechanism is used to pour the washed and neutralized phosphogypsum from the inner cylinder into the drying mechanism.

[0011] In one embodiment of the present invention, the screening mechanism includes a screening box slidably disposed on a frame and a screening drive assembly for driving the screening box to slide left and right to achieve screening of phosphogypsum raw materials.

[0012] A sieve plate is fixedly installed at the bottom of the screening box, and a feed pipe is installed on the screening box to guide phosphogypsum to the middle of the sieve plate;

[0013] Waste discharge pipes are connected to the screening boxes located on both the left and right sides of the sieve plate.

[0014] In one embodiment of the present invention, the screening drive assembly includes a connecting frame slidably connected to the frame, a first screening drive component fixed to the connecting frame, a first connecting rod with one end fixedly connected to the actuating end of the first screening drive component, and a second connecting rod hinged to the other end of the first connecting rod, the other end of the second connecting rod being hinged to the screening box.

[0015] In one embodiment of the present invention, a second screening drive is provided between the frame and the connecting frame.

[0016] In one embodiment of the present invention, the outlet pipe is located above the inlet pipe.

[0017] In one embodiment of the present invention, a drain pipe is provided at the bottom of the box.

[0018] In one embodiment of the present invention, one side of the bottom of the housing is hinged to the frame.

[0019] In one embodiment of the present invention, the tilting mechanism includes a winch fixed to the frame, a hook fixed to the side wall of the housing, and a wire rope with one end connected to the winch and the other end connected to the hook.

[0020] In one embodiment of the present invention, a tilting assist mechanism for assisting the tilting of the box is also included, the tilting assist mechanism including a cylinder fixed on the frame and a rubber block fixed on the piston rod of the cylinder;

[0021] The cylinder piston rod releases to drive the rubber block to press down on the tilting box, thereby increasing the tilting angle of the box.

[0022] In one embodiment of the present invention, the drying mechanism is a rotary dryer.

[0023] As described above, the phosphogypsum pretreatment apparatus of the present invention has the following beneficial effects:

[0024] The screening mechanism is used to screen the phosphogypsum raw material to remove large particles of impurities. Water enters the box and the perforated inner drum through the water inlet pipe. The first drive unit drives the perforated inner drum to rotate intermittently forward and reverse at a first speed, thereby agitating the phosphogypsum inside the inner drum and ensuring full contact between the phosphogypsum and water, thus thoroughly rinsing the phosphogypsum. The rinsed water is then discharged through the water outlet pipe. After rinsing the phosphogypsum, alkaline substances are added to the box through the feeding pipe. The first drive unit again drives the inner drum to rotate intermittently forward and reverse at the first speed to agitate the phosphogypsum inside the inner drum, allowing the acidic and alkaline substances in the phosphogypsum to fully react and achieve neutralization. The water in the box and the perforated inner drum is then discharged through the drain pipe. The first drive unit then drives the inner drum to rotate at a second speed to spin dry the phosphogypsum. The pouring mechanism is used to pour the washed and neutralized phosphogypsum from the perforated inner drum into the drying mechanism for drying, realizing the integration of primary screening, washing, neutralization, and drying, with a high degree of automation and improved pretreatment efficiency of phosphogypsum. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the overall structure of the box in the flat state according to an embodiment of the present invention;

[0026] Figure 2 This is a schematic diagram showing the relationship between the screening mechanism, the washing mechanism, and the tilting mechanism in the case of the box being laid flat according to an embodiment of the present invention.

[0027] Figure 3 This is a schematic diagram of the overall structure of the box in the tilted state according to an embodiment of the present invention;

[0028] Figure 4 This is a schematic diagram showing the relationship between the screening mechanism, the washing mechanism, and the tilting mechanism in the tilted state of the box according to an embodiment of the present invention.

[0029] Figure 5 This is a cross-sectional schematic diagram of the screening box and water tank structure according to an embodiment of the present invention.

[0030] Reference numerals: 1. Frame; 2. Support frame; 3. Screening mechanism; 31. Screening box; 32. Screening drive assembly; 33. Screen plate; 34. Feed pipe; 35. Waste discharge pipe; 321. Connecting frame; 322. First screening drive component; 323. First connecting rod; 324. Second connecting rod; 36. Second screening drive component; 37. Drain pipe; 4. Washing mechanism; 41. Box body; 42. Perforated inner cylinder; 43. First drive component; 44. Water inlet pipe; 45. Water outlet pipe; 46. Feeding pipe; 5. Drying mechanism; 6. Tilting mechanism; 61. Winch; 62. Hook; 63. Wire rope; 7. Tilting auxiliary mechanism; 71. Cylinder; 72. Rubber block. Detailed Implementation

[0031] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0032] Please see Figures 1 to 5 It should be understood that the structures, proportions, sizes, etc., illustrated in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and to facilitate understanding and reading. They are not intended to limit the scope of the invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of the invention, should still fall within the scope of the technical content disclosed in this invention. Furthermore, the terms such as "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity and not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention's implementation.

[0033] Please see Figure 1 and Figure 2 The present invention provides a phosphogypsum pretreatment device, including a frame 1, a screening mechanism 3, a washing mechanism 4, a drying mechanism 5, and a tilting mechanism 6. The mechanisms work together to realize continuous pretreatment of phosphogypsum.

[0034] The screening mechanism 3 is used to perform preliminary screening of phosphogypsum raw materials to remove large particulate impurities, such as unreacted phosphate slag and SiO2. The support frame 2 is bolted to the frame 1, and the screening mechanism 3 is slidably mounted on the support frame 2. The second screening drive component 36 is bolted to the screening mechanism 3. In this embodiment, the second screening drive component 36 can be a linear motor module.

[0035] Please see Figure 1 and Figure 2 The screening mechanism includes a screening box 31 and a screening drive assembly 32. The screening drive assembly 32 includes a connecting frame 321, a first screening drive component 322, a first connecting rod 323, and a second connecting rod 324. The linear motor module drives the connecting frame 321 to slide back and forth on the support frame 2. In this embodiment, the first screening drive component 322 can be a motor bolted to the connecting frame 321. One end of the first connecting rod 323 is fixedly connected to the output shaft of the motor, and one end of the second connecting rod 324 is hinged to the other end of the first connecting rod. The other end of the second connecting rod 324 is hinged to the side wall of the screening box 31. When the motor works, it drives the screening box 31 to vibrate left and right through the first connecting rod 323 and the second connecting rod 324.

[0036] The top of the screening box 31 is integrally formed with a T-shaped slider, and the connecting frame 321 is provided with a sliding groove that cooperates with the sliding of the T-shaped slider. The screening box 31 is slidably connected to the connecting frame 321 through the cooperation of the T-shaped slider and the sliding groove. The drive component drives the screening box 31 to reciprocate left and right to realize the screening of phosphogypsum raw materials and improve the screening efficiency.

[0037] Please see Figure 1 , Figure 2 and Figure 5 A screen plate 33 is bolted to the bottom of the screening box 31. In this embodiment, the diameter of the screen holes on the screen plate 33 can be 2-5mm. An infeed pipe 34 is inclinedly arranged on the side wall of the screening box 31 to guide the phosphogypsum to the middle of the screen plate 33. Waste discharge pipes 35 are connected to the screening boxes 31 on both the left and right sides of the screen plate 33. The waste discharge pipes 35 are used to discharge coarse particle impurities after screening.

[0038] Please see Figure 3 , Figure 4 and Figure 5 The washing mechanism 4 is used to wash and neutralize the phosphogypsum after screening. The washing mechanism 4 includes a housing 41, a perforated inner cylinder 42, and a first driving component 43. The housing 41 is located below the screening box 31, and one side of the bottom of the housing 41 is hinged to the frame 1. The perforated inner cylinder 42 is rotatably disposed inside the housing 41. The filter holes on the cylinder wall of the perforated inner cylinder 42 have a diameter of 0.5-1mm and are used for solid-liquid separation. Furthermore, the diameter of the perforated inner cylinder 42 is larger than the sieve hole area of ​​the sieve plate 33, so that the sieve plate 33 can also be used for solid-liquid separation when it moves left and right. The material falls into the perforated inner cylinder 42; in this embodiment, the first driving component 43 can be a variable frequency motor, wherein the variable frequency motor is bolted to the bottom of the housing 41 and the output shaft of the servo motor is fixedly connected to the perforated inner cylinder 42; the variable frequency motor drives the perforated inner cylinder 42 to run at different speeds; the first speed is 30-60 r / min, intermittently rotating forward and reverse, stirring the phosphogypsum to make it fully contact with water or alkaline solution; the second speed is 800-1000 r / min, high-speed rotation, using centrifugal force to dry the water in the phosphogypsum;

[0039] The first driving component 43 drives the perforated inner cylinder 42 to rotate intermittently in the forward and reverse directions at a first speed, thereby agitating the phosphogypsum inside the inner cylinder, allowing the phosphogypsum to come into full contact with water, and thus enabling the phosphogypsum to be thoroughly rinsed. The rinsed water is then discharged through the outlet pipe 45.

[0040] The first drive unit 43 drives the inner cylinder to rotate intermittently in the first rotation speed to stir the phosphogypsum inside the inner cylinder, so that the acidic and alkaline substances in the phosphogypsum can react fully.

[0041] The first driving component 43 then drives the inner cylinder to rotate at a second speed to spin dry the moisture in the phosphogypsum.

[0042] The bottom of the tank 41 is equipped with a drain pipe 37, which is connected to a solenoid valve. The drain pipe 37 is used to drain wastewater. The side wall of the tank 41 near the bottom is equipped with an inlet pipe 44 and an outlet pipe 45, which is connected to a solenoid valve. The side wall of the tank 41 near the top is also equipped with an outlet pipe 45, which is located above the inlet pipe 44 to facilitate overflow flushing water, so that floating impurities can be discharged through the outlet pipe 45. The side wall of the tank 41 is also equipped with a feeding pipe 46 for adding alkaline substances into the tank 41. The alkaline substance can be lime milk, which is used to neutralize free acid. (The possible chemical reactions are: H3PO4 + Ca(OH)2 → CaHPO4 + 2H2O; 2HF + Ca(OH)2 → CaF2↓ + 2H2O).

[0043] Please see Figure 1 and Figure 2 The tilting mechanism 6 is used to tilt the washed and neutralized phosphogypsum from the perforated inner cylinder 42 to the drying mechanism 5. The tilting mechanism 6 includes a winch 61, a hook 62, and a wire rope 63. The winch 61 is bolted above the washing mechanism 4, the hook 62 is welded to the side wall near the top of the housing 41, one end of the wire rope 63 is fixed to the hook 62, and the other end is fixed to the winch 61. The housing 41 is pulled by the wire rope 63. The housing 41 is tilted by releasing the wire rope 63, and the tilt angle is greater than 90 degrees.

[0044] Please see Figure 3 and Figure 4 The support frame 2 is also equipped with a tilting auxiliary mechanism 7, which includes a cylinder 71 and a rubber block 72. The rubber block 72 is attached to the piston rod of the cylinder 71. When the piston rod of the cylinder 71 is released, the rubber block 72 presses down on the box 41, increasing the tilting angle of the box 41 and ensuring that the phosphogypsum is completely tilted.

[0045] Please see Figure 1 and Figure 3 The drying unit 5 is a rotary dryer, which receives the poured phosphogypsum and performs continuous drying. The neutralized phosphogypsum is sent into the rotary dryer, and the temperature inside the rotary dryer can be adjusted to 105-120℃ to reduce the moisture content to <5%. This facilitates subsequent calcination of the phosphogypsum at different temperatures and grinding with different fineness requirements for different applications.

[0046] Brief description of the usage process: Primary screening: Phosphogypsum raw material enters screening box 31 through feed pipe 34. Screening drive component 32 drives screen plate 33 to vibrate. Fine material under screening falls into water washing mechanism 4, and coarse slag is discharged from waste discharge pipe 35.

[0047] Water washing: Water is injected into the tank 41 and the perforated inner cylinder 42 through the water inlet pipe 44. The solid-liquid ratio is 1:2 to 1:3 for rinsing. The first drive unit 43 drives the perforated inner cylinder 42 to rotate intermittently in the forward and reverse directions at the first speed to stir the phosphogypsum in the inner cylinder. The phosphogypsum is rinsed for 10 to 15 minutes, and the wastewater from the cleaning overflows from the water outlet pipe 45.

[0048] Neutralization: Lime slurry is added through the feed pipe 46, and the first drive unit 43 drives the inner cylinder to rotate intermittently in the first rotation speed to stir the phosphogypsum in the inner cylinder. The reaction is stirred for 30 minutes, and the pH is adjusted to 6.5-7.5.

[0049] Spin-drying: After the neutralization treatment is completed, the wastewater from the box 41 and the perforated inner cylinder 42 is discharged through the drain pipe 37. The first drive unit 43 switches to the second speed to drive the inner cylinder to rotate for spin-drying the water in the phosphogypsum. The centrifugation dehydrates the water content to ≤20%.

[0050] Tilting: The winch 61 releases the wire rope 63 to tilt the box 41, and the piston rod of the cylinder 71 releases the drive rubber block 72 to press down the box 41, increasing the tilting angle of the box 41 and ensuring that the phosphogypsum is completely tilted. The phosphogypsum falls into the rotary dryer to complete the drying process.

[0051] In summary, this invention features an integrated design: primary screening, washing, neutralization, and drying are integrated into the same device, reducing equipment footprint and energy consumption; and automated control: continuous production is achieved through drive speed switching and tilting mechanism 6, reducing manual intervention.

[0052] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A device for pre-treating phosphogypsum, characterized by: The machine frame (1) is provided with a screening mechanism (3) for screening the phosphogypsum raw materials, a water washing mechanism (4) for washing and neutralizing the screened phosphogypsum, a drying mechanism (5) for drying the phosphogypsum, and a pouring mechanism (6) for pouring the washed and neutralized phosphogypsum into the drying mechanism (5). The screening mechanism (3) is used for screening the phosphogypsum raw materials. The screening mechanism (3) comprises a screening box (31) slidingly arranged on the machine frame (1) and a screening drive assembly (32) for driving the screening box (31) to slide left and right to realize the screening of the phosphogypsum raw materials. The screening box (31) is fixedly provided with a screen plate (33) at the bottom, and the screening box (31) is provided with a feeding pipe (34) for guiding the phosphogypsum to the middle of the screen plate (33). The screening box (31) is provided with a waste discharge pipe (35) on both sides of the screen plate (33). The screening drive assembly (32) comprises a connecting frame (321) slidingly connected to the machine frame (1), a first screening drive member (322) fixedly arranged on the connecting frame (321), a first connecting rod (323) fixedly connected to one end of the first screening drive member (322), a second connecting rod (324) hingedly connected to the other end of the first connecting rod (323), and the other end of the second connecting rod (324) is hingedly connected to the screening box (31). The water washing mechanism (4) is used for washing and neutralizing the screened phosphogypsum, and the water washing mechanism (4) comprises a box body (41) hingedly arranged on the machine frame (1), a perforated inner cylinder (42) rotatably arranged in the box body (41), and a first drive member (43) arranged on the box body (41) and used for driving the perforated inner cylinder (42) to rotate. The box body (41) is provided with a water inlet pipe (44) and a water outlet pipe (45), and the box body (41) is provided with a feeding pipe (46) for adding alkaline substances into the box body (41). The first drive member (43) drives the perforated inner cylinder (42) to rotate intermittently at a first rotating speed and a second rotating speed to stir the phosphogypsum to realize sufficient flushing of the phosphogypsum and sufficient reaction of the phosphogypsum and the alkaline substances. The drying mechanism (5) is used for drying the phosphogypsum after the water is spun off. The pouring mechanism (6) is used for pouring the washed and neutralized phosphogypsum from the inner cylinder into the drying mechanism (5).

2. A device for pre-treating phosphogypsum according to claim 1, characterized in that: The pouring auxiliary mechanism (7) is used for assisting the pouring of the box body (41), and the pouring auxiliary mechanism (7) comprises a pneumatic cylinder (71) fixedly arranged on the machine frame (1) and a rubber block (72) fixedly arranged on the piston rod of the pneumatic cylinder (71).

3. The device for pretreating ardealite according to claim 1, characterized in that: The piston rod of the pneumatic cylinder (71) is released to drive the rubber block (72) to press down the box body (41) to increase the pouring angle of the box body (41).

4. The device for pretreating ardealite according to claim 1, characterized in that: The machine frame (1) and the connecting frame (321) are provided with a second screening drive member (36).

5. The device for pretreating ardealite according to claim 1, characterized in that: The water outlet pipe (45) is located above the water inlet pipe (44). The box body (41) is provided with a drain pipe (37) at the bottom. One side of the bottom of the box body (41) is hingedly connected to the machine frame (1).

6. A device for pre-treating phosphogypsum according to claim 1, characterized in that: The pouring mechanism (6) comprises a winch (61) fixed on the frame (1), a hook (62) fixed on the side wall of the box (41), and a steel wire rope (63) with one end connected with the winch (61) and the other end connected with the hook (62).

7. A device for pre-treating phosphogypsum according to claim 1, characterized in that: The drying mechanism (5) is a rotary dryer.

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