A continuous and efficient phosphogypsum purification treatment device

Abstract

This invention discloses a continuous and efficient phosphogypsum purification and treatment device. The device includes a feed inlet, a screw conveyor, a pre-washing tower, a hydrocyclone separator, a neutralization reactor, a settling tank, and a filter press, connected in sequence. The pre-washing tower features a unique staged stirring mechanism, including an upper shear dispersion paddle and a lower vortex propulsion paddle, combined with tangentially arranged spray units and tower wall baffles, to achieve efficient preliminary washing of the phosphogypsum. The hydrocyclone separator separates light impurities such as silica, and the neutralization reactor uses a pH sensor to control the dosage in real time for precise neutralization. After solid-liquid separation in the settling tank, the sludge is dewatered by the filter press to produce purified gypsum. This invention achieves continuous, multi-stage, deep purification of phosphogypsum, with advantages such as smooth process, high efficiency, low energy consumption, and high degree of automation, making it suitable for large-scale resource-based treatment of phosphogypsum.

Description

Technical Field

[0001] This utility model relates to the field of industrial solid waste resource utilization technology, specifically to a continuous and efficient phosphogypsum purification device. Background Technology

[0002] Phosphogypsum is a large-scale industrial solid waste generated during the wet-process phosphoric acid production process, producing approximately 4.5-5 tons of phosphogypsum for every ton of phosphoric acid produced. Its main component is calcium sulfate dihydrate (CaSO4·2H2O), but it typically contains impurities such as undecomposed phosphate rock, free phosphoric acid, fluorides, organic matter, and heavy metals. The presence of these impurities results in low-quality phosphogypsum with poor stability; large-scale stockpiling not only occupies land but also poses a serious threat to the environment, leading to extremely low resource utilization rates.

[0003] Currently, the purification of phosphogypsum mainly employs intermittent methods such as water washing, acid washing, and neutralization. These methods suffer from problems such as long process flows, high equipment investment, high energy consumption, low treatment efficiency, and significant risk of secondary pollution, making large-scale, continuous, and low-cost industrial applications difficult to achieve. Therefore, developing a purification device capable of continuously, efficiently, and deeply removing impurities from phosphogypsum is of great significance for promoting the resource utilization and environmental protection of phosphogypsum. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide a continuous and efficient phosphogypsum purification treatment device, which is reasonable in structure, easy to operate, has high processing efficiency and low operating cost, so as to realize the continuous and large-scale deep purification of phosphogypsum.

[0005] This utility model is achieved through the following scheme: a continuous and efficient phosphogypsum purification treatment device, including a feed inlet, a screw conveyor, a pre-washing tower, a hydrocyclone separator, a neutralization reactor, a settling tank, and a filter press; the screw conveyor is arranged between the feed inlet and the pre-washing tower; the pre-washing tower is equipped with a washing liquid spraying unit and an axial agitator; the bottom end of the pre-washing tower is connected to the feed inlet of the hydrocyclone separator through a wear-resistant pipe; the hydrocyclone separator has a clear liquid outlet at the top and a conical sludge outlet at the bottom; the sludge outlet of the hydrocyclone separator is connected to the feed area of ​​the neutralization reactor through a controllable flow rate conveying pipeline; the neutralization reactor is equipped with a multi-stage pH sensor and a mechanical agitator, and has a chemical dosing port at the top; the discharge end of the neutralization reactor is connected to the upper middle part of the settling tank; the settling tank has an annular overflow trough around the top periphery and a conical sludge collection hopper at the bottom; the sludge collection hopper outlet of the settling tank is connected to the feed inlet of the filter press through a sludge pump.

[0006] The pre-washing tower includes a tower body, a drive motor located at the top of the tower body, a central rotating shaft coaxially located inside the tower body, and a stirring mechanism fixed to the central rotating shaft.

[0007] The stirring mechanism includes multiple sets of stirring paddle units arranged from top to bottom, with shear dispersion paddles in the upper layer and vortex propulsion paddles in the lower layer; multiple fixed guide baffles are evenly arranged on the inner wall of the tower body; the tangentially arranged washing liquid spraying unit includes a spray ring pipe located above the shear dispersion paddle, and the spray ring pipe is provided with multiple fan-shaped nozzles facing the tower wall; the bottom of the tower body is designed as a W-shaped or conical bottom, and its lowest point is connected to the cyclone separator through the wear-resistant pipe.

[0008] The spray ring pipe has a concentric double-layer structure, including an outer spray ring pipe and an inner spray ring pipe. The outer spray ring pipe and the inner spray ring pipe are fixedly connected by radially distributed horizontal pipes to achieve fluid communication. The horizontal pipes are connected to the liquid inlet pipe of the pre-washing tower.

[0009] The angle between the axis of the fan-shaped nozzle on the outer spray ring pipe and the tangent to the inner wall of the tower is 10°-30°, and the angle between the axis of the fan-shaped nozzle on the inner spray ring pipe and the tangent to the inner wall of the tower is 30°-50°.

[0010] The number of guide baffles is 4-8, evenly distributed along the circumference of the tower body, and arranged vertically, interspersed with the blades of the shearing and dispersing impeller. A pneumatic clamp valve or an automatic sand discharge valve controlled by a densitometer is installed at the conical sludge outlet of the cyclone separator.

[0011] The angle between the conical sludge hopper sidewall of the settling tank and the horizontal plane is not less than 60°.

[0012] The beneficial effects of this utility model are as follows:

[0013] 1. The continuous and efficient phosphogypsum purification treatment device of this utility model adopts an integrated linkage design, realizing continuous operation of the entire process from feeding to output purified gypsum, with large processing capacity and high efficiency.

[0014] 2. The continuous and efficient phosphogypsum purification device of this utility model removes impurities of different properties and particle sizes step by step through a multi-stage combined process of "pre-washing tower initial washing + cyclone separation and classification + neutralization reaction deep purification". The purification effect is good and the product purity is significantly improved.

[0015] 3. The optimized stirring and spraying structure in the pre-washing tower of the continuous high-efficiency phosphogypsum purification treatment device of this utility model enhances the washing effect and reduces the consumption of water and reagents; the neutralization reactor realizes automatic and precise dosing through pH sensor, which reduces the intensity of manual operation and ensures the stability of reaction.

[0016] 4. The key equipment of this utility model's continuous and efficient phosphogypsum purification device, such as the bottom of the pre-washing tower, the sand discharge port of the hydrocyclone separator, and the sludge collection hopper of the settling tank, has been optimized for the characteristics of phosphogypsum slurry, effectively preventing clogging and wear, and ensuring the long-term stable operation of the device. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall system structure of a continuous and efficient phosphogypsum purification device according to the present invention.

[0018] Figure 2 This is a front view cross-sectional structural diagram of the pre-washing tower of a continuous and efficient phosphogypsum purification treatment device according to this utility model.

[0019] Figure 3 This is a schematic diagram of the spray ring pipe from the front and bottom view of Embodiment 2 of the continuous high-efficiency phosphogypsum purification treatment device of this utility model.

[0020] In the diagram: 1 is the feed inlet, 2 is the screw conveyor, 3 is the pre-washing tower, 31 is the tower body, 32 is the drive motor, 33 is the central rotating shaft, 34 is the shearing and dispersing paddle, 35 is the vortex propulsion paddle, 36 is the guide baffle, 37 is the spray ring pipe, 371 is the outer spray ring pipe, 372 is the inner spray ring pipe, 373 is the horizontal pipe, 38 is the fan-shaped nozzle, 4 is the hydrocyclone separator, 5 is the neutralization reactor, 6 is the settling tank, and 7 is the filter press. Detailed Implementation

[0021] The following is combined with Figure 1-3 The present invention will be further described below, but the scope of protection of the present invention is not limited to the contents described herein.

[0022] Example 1

[0023] Reference Figure 1 and Figure 2 This embodiment provides a continuous and efficient phosphogypsum purification treatment device, including a feed inlet 1, a screw conveyor 2, a pre-washing tower 3, a hydrocyclone separator 4, a neutralization reactor 5, a settling tank 6, and a filter press 7.

[0024] The feed inlet 1 is connected to the feed end of the pre-washing tower 3 via a screw conveyor 2, and is used to continuously and uniformly feed the phosphogypsum raw material into the pre-washing tower 3.

[0025] The pre-washing tower 3 is equipped with a washing liquid spraying unit and an axial agitator. Specifically, the pre-washing tower 3 includes a tower body 31, a drive motor 32, a central rotating shaft 33, and a stirring mechanism. The drive motor 32 is mounted on the top of the tower body 31 and drives the stirring mechanism to rotate via the central rotating shaft 33. The stirring mechanism includes multiple sets of stirring blade units arranged from top to bottom, with shear dispersion blades 34 in the upper layer and vortex propulsion blades 35 in the lower layer. Four to eight vertically arranged guide baffles 36 are uniformly fixed to the inner wall of the tower body 31. These guide baffles 36 are staggered with the blades of the shear dispersion blades 34 to enhance fluid turbulence and avoid washing dead zones.

[0026] The washing liquid spraying unit includes a spray ring pipe 37 located above the shear dispersion paddle 34. The spray ring pipe 37 is equipped with multiple fan-shaped nozzles 38 tangentially facing the tower wall to form a swirling liquid curtain and improve the washing coverage. The bottom of the tower body 31 is preferably a W-shaped or conical structure, and its lowest point is connected to the feed inlet of the cyclone separator 4 through a wear-resistant pipe to ensure that the material is discharged smoothly and does not easily settle.

[0027] The cyclone separator 4 is provided with a clear liquid outlet at the top and a conical sludge outlet at the bottom. A pneumatic clamp valve or an automatic sand discharge valve controlled by a densitometer is installed at the sludge outlet to achieve automatic adjustment and stable discharge of the underflow concentration.

[0028] The sludge outlet of the hydrocyclone separator 4 is connected to the feed area of ​​the neutralization reactor 5 via a controllable flow rate conveying pipeline. The neutralization reactor 5 is equipped with multi-stage pH sensors and mechanical stirrers, and has a dosing port at the top for automatically adding neutralizing agents based on pH feedback signals, ensuring precise and controllable reaction process.

[0029] The discharge end of the neutralization reactor 5 is connected to the upper middle part of the settling tank 6. The settling tank 6 has an annular overflow trough around its top perimeter for collecting the supernatant; the bottom is a conical sludge collection hopper with its sidewall forming an angle of not less than 60° with the horizontal plane to ensure smooth sludge collection. The sludge collection hopper outlet of the settling tank 6 is connected to the feed inlet of the filter press 7 via a sludge pump to complete the final dewatering of the sludge.

[0030] Example 2

[0031] Based on the structure of Example 1, this embodiment further optimizes the spray ring pipe in the pre-washing tower 3.

[0032] Reference Figure 3 The spray ring pipe 37 adopts a concentric double-layer structure, including an outer spray ring pipe 371 and an inner spray ring pipe 372. The outer spray ring pipe 371 and the inner spray ring pipe 372 are fixedly connected by multiple evenly distributed radial horizontal pipes 373 to achieve fluid communication. The horizontal pipes 373 are connected to the liquid inlet pipe of the pre-washing tower 3 to achieve uniform distribution of washing liquid.

[0033] To further optimize the spray flow field and improve cleaning efficiency, the fan-shaped nozzles 38 on the outer spray ring pipe 371 have an angle of 10° to 30° with the tangent to the inner wall of the tower body 31 to form a wall-adhering swirling flow; the fan-shaped nozzles 38 on the inner spray ring pipe 372 have an angle of 30° to 50° with the tangent to the inner wall of the tower body 31 to enhance the liquid curtain coverage and turbulent mixing in the central area. This structure effectively expands the washing area and significantly improves the uniformity of material cleaning and the efficiency of impurity removal.

[0034] Although the technical solutions of this utility model have been described and enumerated in detail, it should be understood that modifications to the above embodiments or the adoption of equivalent alternatives are obvious to those skilled in the art. Such modifications or improvements made without departing from the spirit of this utility model are all within the scope of protection claimed by this utility model.

Claims

1. A continuous high-efficiency phosphogypsum impurity removal and purification treatment device, characterized in that, The system includes a feed inlet (1), a screw conveyor (2), a pre-washing tower (3), a hydrocyclone separator (4), a neutralization reactor (5), a settling tank (6), and a filter press (7); the screw conveyor (2) is installed between the feed inlet (1) and the pre-washing tower (3); the pre-washing tower (3) is equipped with a washing liquid spraying unit and an axial agitator; the bottom of the pre-washing tower (3) is connected to the feed inlet of the hydrocyclone separator (4) through a wear-resistant pipe; the hydrocyclone separator (4) has a clear liquid outlet at the top and a conical sludge outlet at the bottom. The sludge outlet of the hydrocyclone separator (4) is connected to the feed area of ​​the neutralization reactor (5) via a controllable flow rate conveying pipeline. The neutralization reactor (5) is equipped with a multi-stage pH sensor and a mechanical stirrer, and has a dosing port at the top. The discharge end of the neutralization reactor (5) is connected to the upper middle part of the settling tank (6). The settling tank (6) has an annular overflow trough around the top periphery and a conical sludge collection hopper at the bottom. The sludge collection hopper outlet of the settling tank (6) is connected to the feed port of the filter press (7) via a sludge pump.

2. The continuous high-efficiency phosphogypsum purification device according to claim 1, characterized in that, The pre-washing tower (3) includes a tower body (31), a drive motor (32) disposed at the top of the tower body, a central rotating shaft (33) coaxially disposed in the tower body, and a stirring mechanism fixed on the central rotating shaft (33); The stirring mechanism includes multiple sets of stirring paddle units arranged from top to bottom, with a shear dispersion paddle (34) on the upper layer and a vortex propulsion paddle (35) on the lower layer; the inner wall of the tower body (31) is uniformly provided with multiple fixed flow guide baffles (36); the tangentially arranged washing liquid spraying unit includes a spray ring pipe (37) located above the shear dispersion paddle (34), and the spray ring pipe (37) is provided with multiple fan-shaped nozzles facing the tower wall; the bottom of the tower body (31) is designed as a W-shaped or conical bottom, and its lowest point is connected to the cyclone separator (4) through the wear-resistant pipe.

3. The continuous high-efficiency phosphogypsum purification device according to claim 2, characterized in that, The spray ring pipe (37) has a concentric double-layer structure, including an outer spray ring pipe (371) and an inner spray ring pipe (372). The outer spray ring pipe (371) and the inner spray ring pipe (372) are fixedly connected by radially distributed horizontal pipes (373) to achieve fluid communication. The horizontal pipes (373) are connected to the liquid inlet pipe of the pre-washing tower (3).

4. The continuous high-efficiency phosphogypsum impurity purification treatment device according to claim 3, characterized in that, The angle between the axis of the fan-shaped nozzle on the outer spray ring pipe (371) and the tangent of the inner wall of the tower body (31) is 10°-30°, and the angle between the axis of the fan-shaped nozzle on the inner spray ring pipe (372) and the tangent of the inner wall of the tower body (31) is 30°-50°.

5. The continuous high-efficiency phosphogypsum impurity purification treatment device according to claim 2, characterized in that, The number of the flow guide baffles (36) is 4-8, which are evenly distributed along the circumference of the tower body and are arranged vertically and staggered with the blades of the shearing and dispersing paddle (34).

6. The continuous high-efficiency phosphogypsum impurity purification treatment device according to claim 1, characterized in that: The conical sludge outlet of the cyclone separator (4) is equipped with a pneumatic clamp valve or an automatic sand discharge valve controlled by a densitometer.

7. The continuous high-efficiency phosphogypsum purification device according to claim 1, characterized in that: The angle between the conical sludge hopper sidewall of the settling tank (6) and the horizontal plane is not less than 60°.

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