Efficient dehydration method for ardealite

Abstract

The invention provides an efficient dewatering method for phosphogypsum, and relates to the technical field of washing, dewatering and recycling phosphogypsum generated by industrial treatment of phosphorite. According to the method, a membrane breaking device, a scattering device and an air blowing device are newly added on the basis of a traditional belt filter and are combined with vacuum filtration; the method comprises the following steps: after solid-liquid mixed phosphogypsum is subjected to vacuum filtration, redundant free water is pumped out, so that the phosphogypsum is hardened, and an organic medicament film is formed on the surface to influence the suction filtration efficiency; an organic medicament film on the surface of the material is broken through the film breaking device, so that air can penetrate through phosphogypsum, and the water content of the material is further reduced; fully scattering the phosphogypsum subjected to suction filtration by a scattering device; and hot air generated by the air blowing device is used for drying the fully-scattered phosphogypsum, so that dried phosphogypsum powder is obtained. A set of efficient phosphogypsum suction filtration mechanism is established, the water content of the phosphogypsum finished product is reduced, the industrial cost is effectively reduced, and the efficiency is improved.

Description

[0001] The invention relates to the technical field of phosphogypsum treatment, and in particular to a method for efficiently dehydrating phosphogypsum. Background Art

[0002] Phosphogypsum is a byproduct of phosphoric acid production, and its main component is calcium sulfate dihydrate. Since phosphogypsum contains a large amount of water and impurities, its direct discharge not only occupies a large amount of land resources, but also causes serious environmental pollution. Therefore, the dehydration treatment of phosphogypsum has become the focus of research and engineering application.

[0003] The dehydration process of phosphogypsum can not only reduce its moisture content, making it suitable for resource utilization such as building materials and agricultural fertilizers, but also reduce the occupation of storage sites and reduce environmental risks. Common methods for dehydrating phosphogypsum include natural drying, hot air drying, filter press dehydration and chemical dehydration. Among them, filter press dehydration has been widely used due to its high dehydration efficiency and simple operation. However, problems such as filter cloth clogging and slow filtration speed are prone to occur during the filter press process, which affects the dehydration effect.

[0004] Chemical dehydration methods have also received extensive attention and research in the field of phosphogypsum treatment. For example, acid treatment or salting out can effectively remove impurities and some water in phosphogypsum, thereby improving its physical properties and facilitating subsequent utilization. In addition, new technologies such as microwave drying and ultrasonic-assisted dehydration are also gradually being applied to the dehydration process of phosphogypsum, showing good application prospects, but the operation is difficult and the cost is high.

[0005] Therefore, it is necessary to provide a method for efficiently dehydrating phosphogypsum to overcome the above problems. Summary of the invention

[0006] In view of this, the present invention proposes a method for efficiently dehydrating phosphogypsum, which is used to solve the problems of low efficiency and high cost in the dehydration process of phosphogypsum. The present invention adopts the following technical scheme: A method for efficiently dehydrating phosphogypsum, characterized in that it includes the following steps: S1. Add the phosphogypsum byproduct obtained from the treatment of phosphate rock into the stirring tank for slurry treatment, and the concentration of the slurry is 65%~75%; S2. Pump the slurry into the distributor of the new high-efficiency phosphogypsum filter and spread it evenly on the filter cloth by the distributor; S3. The free water in the slurry is extracted by a new high-efficiency phosphogypsum filter, making the material in a solid compacted state; S4. An organic agent film is formed on the surface of the hardened phosphogypsum, which affects the dehydration efficiency. The film breaking device effectively cuts the organic agent film apart; S5. The material cut by the organic agent film is transported to the dispersing device, and the dispersing device fully disperses the compacted phosphogypsum; S6. The phosphogypsum that is fully dispersed in step S5 is transported to a box-type air distribution device for hot air drying to effectively reduce the water content of the phosphogypsum.

[0007] A further technical solution is that the solid content of phosphogypsum in the phosphogypsum slurry in step S1 is 60% to 70%.

[0008] A further technical solution is: the membrane breaking device described in step S4 uses pneumatic power and shares a set of pneumatic devices with the new high-efficiency phosphogypsum filter, and the movement form of the membrane breaking device is back and forth reciprocating motion.

[0009] A further technical solution is that the breaking up device described in step S5 is a roller with staggered blades, which can effectively break up the compacted phosphogypsum.

[0010] A further technical solution is that the box-type air distribution device described in step S6 needs to continue to blow hot air to disperse the phosphogypsum for 2 minutes to 3 minutes.

[0011] A further technical solution is: the heating system of the cassette air distribution device described in step S6 needs to control the air source outlet temperature at 60°C~80°C.

[0012] Working principle: The prepared phosphogypsum slurry is pumped to the distributor and evenly spread on the filter cloth. After vacuum filtration, a layer of organic agent film is formed on the surface of the phosphogypsum, which prevents air from entering and affects the efficiency of vacuum filtration. The organic agent film is completely cut open by the film breaking device, so that air can enter the interior of the phosphogypsum, improving the effectiveness of vacuum filtration. The breaking device fully breaks up the phosphogypsum, and the box-type air distribution device performs hot air blowing on the broken materials to minimize the moisture content of the phosphogypsum.

[0013] Compared with the prior art, the beneficial effects of the present invention are: the present invention innovates a new method for dehydrating phosphogypsum, combines membrane breaking, breaking up, and drying with a belt filter for the first time, establishes a set of mechanisms for efficient extraction and filtration of phosphogypsum, and effectively solves the problem of high moisture content of the finished phosphogypsum during extraction by a traditional belt filter; the combination of a membrane breaking device, a breaking up device, and a cassette-type air distribution device can reduce the moisture content of the phosphogypsum to the greatest extent, thereby simplifying the work process, reducing production costs, improving efficiency, and facilitating industrial transformation. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 :It is the process flow chart of the present invention.

[0015] Figure 2 : It is the structural diagram of the novel high-efficiency phosphogypsum filter using the method of the present invention.

[0016] In the figure, 1. distributor; 2. film breaking device; 3. breaking device; 4. box-type blowing device; 5. new high-efficiency phosphogypsum filter; 6. filter cloth. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0018] In order to achieve the above technical objectives, the technical solution of the present invention provides a method for efficiently dehydrating phosphogypsum, which specifically comprises the following steps: S1. Add the phosphogypsum byproduct obtained from the treatment of phosphate rock into the stirring tank for slurry treatment, and the concentration of the slurry is 65%~75%; S2. The slurry is pumped into the distributor 1 of the new high-efficiency phosphogypsum filter 5, and is evenly spread on the filter cloth 6 by the distributor 1; S3. The free water in the slurry is extracted by a new high-efficiency phosphogypsum filter 5, so that the material is in a solid state; S4. A layer of organic agent film is formed on the surface of the hardened phosphogypsum, which affects the efficiency of dehydration, and the film breaking device 2 effectively cuts the organic agent film; S5. The material cut by the organic agent film is transported to the dispersing device 3, and the dispersing device 3 is used to fully disperse the hardened phosphogypsum; S6. The phosphogypsum that is fully dispersed in step S5 is transported to the box-type air distribution device 4 for hot air drying treatment, thereby effectively reducing the water content of the phosphogypsum.

[0019] The specific process includes the following:

[0020] 1. Distribution: The evenly stirred phosphogypsum slurry with a solid content of 60% to 70% is distributed to the front end of the new high-efficiency phosphogypsum filter to form a phosphogypsum layer of uniform thickness, with a thickness of 2 to 3 cm.

[0021] 2. Film breaking: The film breaking device is driven by pressurized gas generated by air pressure, which makes it reciprocate on the surface of the phosphogypsum layer to break the organic agent film formed on the surface of the phosphogypsum layer, so that the phosphogypsum layer is more breathable.

[0022] 3. Breakup: The breaking device is driven by a motor, which drives the breaking blades to break up the filtered phosphogypsum layer to make it loose and porous for subsequent drying operations.

[0023] 4. Drying: The box-type air distribution device blows air evenly to dry the dispersed phosphogypsum. The outlet temperature is controlled at 60℃~80℃, and the crawler speed of the new high-efficiency phosphogypsum filter is controlled to make the blowing and drying time 2min~3min, and the hot air outlet volume is 325m 3 / min, to prepare phosphogypsum products with different moisture contents.

[0024] Example 1.

[0025] This embodiment uses phosphogypsum from a certain place in Hubei as raw material. The specific steps are as follows: (1) Distribution: The phosphogypsum slurry with a solid content of 60% to 70% that has been evenly stirred is distributed to the front end of the new high-efficiency phosphogypsum filter to form a phosphogypsum layer of uniform thickness, with a thickness of 2 to 3 cm; (2) Film breaking: The film breaking device is driven by the pressurized gas generated by the air compressor, causing it to reciprocate on the surface of the phosphogypsum layer, breaking the organic agent film formed on the surface of the phosphogypsum layer so that the phosphogypsum layer is more permeable; (3) Breaking up: The breaking up device is driven by a motor, which drives the breaking up blades to break up the phosphogypsum layer after filtration, making it loose and porous for subsequent drying operations; (4) Drying: The box-type air distribution device blows air evenly to dry the dispersed phosphogypsum. The outlet temperature is controlled at 70°C, and the crawler speed of the new high-efficiency phosphogypsum filter is controlled so that the drying time is 2.5 minutes and the hot air outlet volume is 325m 3 / min, the moisture content of the prepared phosphogypsum product is about 17.5%.

[0026] Example 2.

[0027] This embodiment uses phosphogypsum from a certain place in Hubei as raw material. The specific steps are as follows: (1) Distribution: The phosphogypsum slurry with a solid content of 60% to 70% that has been evenly stirred is distributed to the front end of the new high-efficiency phosphogypsum filter to form a phosphogypsum layer of uniform thickness, with a thickness of 2 to 3 cm; (2) Film breaking: The film breaking device is driven by the pressurized gas generated by the air compressor, causing it to reciprocate on the surface of the phosphogypsum layer, breaking the organic agent film formed on the surface of the phosphogypsum layer so that the phosphogypsum layer is more permeable; (3) Breaking up: The breaking up device is driven by a motor, which drives the breaking up blades to break up the phosphogypsum layer after filtration, making it loose and porous for subsequent drying operations; (4) Drying: The box-type air distribution device blows air evenly to dry the dispersed phosphogypsum. The outlet temperature is controlled at 70°C, and the crawler speed of the new high-efficiency phosphogypsum filter is controlled so that the drying time is 3 minutes and the hot air outlet volume is 325m 3 / min, the moisture content of the prepared phosphogypsum product is about 16%.

[0028] Example 3.

[0029] This embodiment uses phosphogypsum from a certain place in Hubei as raw material. The specific steps are as follows: (1) Distribution: The phosphogypsum slurry with a solid content of 60% to 70% that has been evenly stirred is distributed to the front end of the new high-efficiency phosphogypsum filter to form a phosphogypsum layer of uniform thickness, with a thickness of 2 to 3 cm; (2) Film breaking: The film breaking device is driven by the pressurized gas generated by the air compressor, causing it to reciprocate on the surface of the phosphogypsum layer, breaking the organic agent film formed on the surface of the phosphogypsum layer so that the phosphogypsum layer is more permeable; (3) Breaking up: The breaking up device is driven by a motor, which drives the breaking up blades to break up the phosphogypsum layer after filtration, making it loose and porous for subsequent drying operations; (4) Drying: The box-type air distribution device blows air evenly to dry the dispersed phosphogypsum. The outlet temperature is controlled to be the ambient temperature, and the crawler speed of the new high-efficiency phosphogypsum filter is controlled to make the drying time of blowing air 3 minutes and the hot air outlet volume 325m 3 / min, the moisture content of the prepared phosphogypsum product is about 22%.

[0030] Example 4.

[0031] This embodiment uses phosphogypsum from a certain place in Hubei as raw material. The specific steps are as follows: (1) Distribution: The phosphogypsum slurry with a solid content of 60% to 70% that has been evenly stirred is distributed to the front end of the new high-efficiency phosphogypsum filter to form a phosphogypsum layer of uniform thickness, with a thickness of 2 to 3 cm; (2) Film breaking: The film breaking device is driven by the pressurized gas generated by the air compressor, causing it to reciprocate on the surface of the phosphogypsum layer, breaking the organic agent film formed on the surface of the phosphogypsum layer so that the phosphogypsum layer is more permeable; (3) Breaking up: The breaking up device is driven by a motor, which drives the breaking up blades to break up the phosphogypsum layer after filtration, making it loose and porous for subsequent drying operations; (4) Drying: The box-type air distribution device blows air evenly to dry the dispersed phosphogypsum. The outlet temperature is controlled at 70°C, and the crawler speed of the new high-efficiency phosphogypsum filter is controlled so that the drying time is 2.5 minutes and the hot air outlet volume is 325m 3 / min, the moisture content of the prepared phosphogypsum product is about 18%.

[0032] Example 5.

[0033] This embodiment uses phosphogypsum from a certain place in Hubei as raw material. The specific steps are as follows: (1) Distribution: The phosphogypsum slurry with a solid content of 60% to 70% that has been evenly stirred is distributed to the front end of the new high-efficiency phosphogypsum filter to form a phosphogypsum layer of uniform thickness, with a thickness of 2 to 3 cm; (2) Film breaking: The film breaking device is driven by the pressurized gas generated by the air compressor, causing it to reciprocate on the surface of the phosphogypsum layer, breaking the organic agent film formed on the surface of the phosphogypsum layer so that the phosphogypsum layer is more permeable; (3) Breaking up: The breaking up device is driven by a motor, which drives the breaking up blades to break up the phosphogypsum layer after filtration, making it loose and porous for subsequent drying operations; (4) Drying: The box-type air distribution device blows air evenly to dry the dispersed phosphogypsum. The outlet temperature is controlled at 70°C, and the crawler speed of the new high-efficiency phosphogypsum filter is controlled so that the drying time is 2.5 minutes and the hot air outlet volume is 325m 3 / min, the moisture content of the prepared phosphogypsum product is about 16.5%.

[0034] Example 6.

[0035] This embodiment uses phosphogypsum from a certain place in Hubei as raw material. The specific steps are as follows: (1) Distribution: The phosphogypsum slurry with a solid content of 60% to 70% that has been evenly stirred is distributed to the front end of the new high-efficiency phosphogypsum filter to form a phosphogypsum layer of uniform thickness, with a thickness of 2 to 3 cm; (2) Film breaking: The film breaking device is driven by the pressurized gas generated by the air compressor, causing it to reciprocate on the surface of the phosphogypsum layer, breaking the organic agent film formed on the surface of the phosphogypsum layer so that the phosphogypsum layer is more permeable; (3) Breaking up: The breaking up device is driven by a motor, which drives the breaking up blades to break up the phosphogypsum layer after filtration, making it loose and porous for subsequent drying operations; (4) Drying: The box-type air distribution device blows air evenly to dry the dispersed phosphogypsum. The outlet temperature is controlled to be the ambient temperature, and the crawler speed of the new high-efficiency phosphogypsum filter is controlled to make the drying time of blowing air 3 minutes and the hot air outlet volume 325m 3 / min, the moisture content of the prepared phosphogypsum product is about 22.7%.

[0036] Comparative example 1.

[0037] This comparative example uses phosphogypsum from a certain place in Hubei as raw material. The specific steps are as follows: (1) Distribution: The phosphogypsum slurry with a solid content of 60% to 70% that has been evenly stirred is distributed to the front end of the new high-efficiency phosphogypsum filter to form a phosphogypsum layer of uniform thickness, with a thickness of 2 to 3 cm; (2) Filtration: Without opening the membrane breaking device, the breaking device and the non-interval box-type air distribution device, the moisture content of the prepared phosphogypsum product is about 25.6%.

[0038] Comparative example 2.

[0039] This comparative example uses phosphogypsum from a certain place in Hubei as raw material. The specific steps are as follows: (1) Distribution: The phosphogypsum slurry with a solid content of 60% to 70% that has been evenly stirred is distributed to the front end of the new high-efficiency phosphogypsum filter to form a phosphogypsum layer of uniform thickness, with a thickness of 2 to 3 cm; (2) Filtration: Without opening the membrane breaking device, the breaking device and the non-interval box-type air distribution device, the moisture content of the prepared phosphogypsum product is about 25.3%.

[0040] It should be noted that the present invention is a method for efficiently dehydrating phosphogypsum. Before use, the air tightness and installation tightness of the pipeline must be checked, and the installation positions of the film breaking device, the breaking device, and the non-spaced box-type air distribution device must be checked. During the dehydration and drying process, the state of the phosphogypsum must be observed, and the installation positions of the film breaking device, the breaking device, and the non-spaced box-type air distribution device must be checked and adjusted at any time to ensure the efficient operation of the new high-efficiency phosphogypsum filter and to produce phosphogypsum products that meet the requirements.

[0041] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Although the present invention is described herein with reference to a plurality of illustrative embodiments of the present invention, it should be understood that a person skilled in the art can design many other modifications and implementations, which will fall within the scope disclosed in the present application. More specifically, within the scope disclosed in the present application, the drawings and the claims, a variety of deformations and improvements may be made to the components or layout. In addition to the deformations and improvements made to the components or layout, other uses will also be obvious to a person skilled in the art, and should all be included in the scope of protection of the claims of the present invention.

Claims

1. A method for efficiently dehydrating phosphogypsum, characterized in that The steps include: S1. Add the phosphogypsum byproduct obtained from the treatment of phosphate rock into the stirring tank for slurry treatment, and the slurry concentration is 65%~75%; S2. The slurry is pumped into the distributor (1) of the new high-efficiency phosphogypsum filter (5), and the distributor (1) evenly spreads the slurry on the filter cloth (6); S3. The free water in the slurry is extracted by a new high-efficiency phosphogypsum filter (5), so that the material is in a solid state; S4. A layer of organic agent film is formed on the surface of the hardened phosphogypsum, which affects the dehydration efficiency. The film breaking device (2) effectively cuts the organic agent film; S5. The material cut by the organic agent film is transported to the dispersing device (3), and the dispersing device (3) fully disperses the compacted phosphogypsum; S6. The phosphogypsum that has been fully dispersed in step S5 is transported to the box-type air distribution device (4) for hot air drying, thereby effectively reducing the water content of the phosphogypsum.

2. A method for efficiently dehydrating phosphogypsum according to claim 1, characterized in that: The solid content of phosphogypsum in the phosphogypsum slurry described in step S1 is 60% to 70%.

3. A method for efficiently dehydrating phosphogypsum according to claim 1, characterized in that: The membrane breaking device (2) described in step S4 uses pneumatic power and shares a set of pneumatic devices with the new high-efficiency phosphogypsum filter (5). The movement form of the membrane breaking device (2) is a back-and-forth reciprocating motion.

4. A method for efficiently dehydrating phosphogypsum according to claim 1, characterized in that: The breaking up device (3) in step S5 is a roller with staggered blades, which can effectively break up the compacted phosphogypsum.

5. The method for efficiently dehydrating phosphogypsum according to claim 1, characterized in that: The box-type air distribution device (4) described in step S6 needs to continue to blow hot air to disperse the phosphogypsum for 2 minutes to 3 minutes.

6. The method for efficiently dehydrating phosphogypsum according to claim 1, characterized in that: The heating system of the cassette air distribution device (4) described in step S6 needs to control the air source outlet temperature to 60° C. to 80° C.

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