An efficient phosphogypsum treatment system

Abstract

The present invention relates to phosphogypsum. In order to improve the processing efficiency of phosphogypsum, an efficient phosphogypsum processing system is provided, comprising a phosphoric acid extraction system, a first processing system connected to a waste material discharge end of the phosphoric acid extraction system, and a second processing system connected to the first processing system; the waste material outlet end of the phosphoric acid extraction system is connected to the second processing system. The efficient phosphogypsum processing system of the present invention can process phosphogypsum more efficiently and systematically, and has a higher utilization rate of phosphogypsum.

Description

Technical Field

[0001] The present invention relates to the technical field of phosphogypsum, and in particular to an efficient phosphogypsum processing system. Background Art

[0002] There are two main types of phosphogypsum: gray-black and gray-white. The particle diameter is generally 5-50um and the crystal water content is 20%-25%. Phosphogypsum is a solid waste produced in the wet phosphoric acid process, and its main component is calcium sulfate dihydrate. The composition of phosphogypsum is relatively complex. In addition to calcium sulfate, there are also incompletely decomposed phosphate ore, residual phosphoric acid, fluoride, acid insoluble matter, organic matter, etc. Among them, the presence of fluorine and organic matter has the greatest impact on the resource utilization of phosphogypsum. The random discharge and accumulation of phosphogypsum has seriously damaged the ecological environment, not only polluting groundwater resources, but also causing waste of land resources.

[0003] In the existing treatment systems, phosphogypsum is basically piled up as waste and then recycled when needed. However, the recycling of phosphogypsum is relatively cumbersome and has low economic benefits, so the utilization rate of phosphogypsum has always been low. In addition, in the process of recycling phosphogypsum, the removal of phosphorus, fluorine, organic matter, etc. in the phosphogypsum also involves the emission of pollutants. Therefore, the common phosphogypsum recycling and treatment system cannot achieve a high utilization rate.

[0004] In summary, designing a more systematic and more efficient phosphogypsum treatment system can better solve the phosphogypsum problem. Summary of the invention

[0005] The object of the present invention is to provide an efficient phosphogypsum processing system, which can process phosphogypsum more efficiently and systematically and has a higher utilization rate of phosphogypsum.

[0006] An embodiment of the present invention is achieved through the following technical scheme: the efficient phosphogypsum treatment system of the present invention includes a phosphoric acid extraction system, a first treatment system connected to the waste discharge end of the phosphoric acid extraction system, and a second treatment system connected to the first treatment system; the waste outlet end of the phosphoric acid extraction system is connected to the second treatment system.

[0007] Furthermore, the first treatment system includes a water washing device connected to the phosphoric acid extraction system. The first treatment system also includes a first mixing device connected to the discharge end of the water washing device, and the discharge end of the first mixing device is connected to the feed end of the second treatment system. The first treatment system is mainly used to remove impurities such as soluble phosphorus, eutectic phosphorus, fluorine, and organic matter in phosphogypsum, and the present invention is treated by combining water washing + lime neutralization, but there are many known methods for treating phosphogypsum, so the first treatment system of the present invention can also use lime neutralization + ball milling, lime neutralization + flotation, lime neutralization + calcination, flotation + ball milling, acid leaching + water washing and other combined processes.

[0008] Furthermore, the second processing system comprises a second mixing device, and a feed end of the second mixing device is connected to a discharge end of the first mixing device.

[0009] Furthermore, the waste material discharge end of the water washing device is connected to the feed end of the second mixing device.

[0010] Furthermore, the waste material discharge end of the first mixing device is connected to the feed end of the second mixing device.

[0011] Furthermore, the waste material discharge end of the phosphoric acid extraction system is connected to the feed end of the second mixing device.

[0012] Furthermore, the phosphoric acid extraction system includes a plurality of raw material tanks, an extraction tank connected to the raw material tanks, and a phosphoric acid storage tank connected to the extraction tank; the waste material discharge end of the extraction tank is connected to the first processing system.

[0013] Furthermore, it also includes a first storage tank connected to the discharge end of the first mixing device and a second storage tank connected to the discharge end of the second mixing device.

[0014] The technical solution of the embodiment of the present invention has at least the following advantages and beneficial effects: the efficient phosphogypsum treatment system of the present invention uses the production process of wet phosphoric acid (i.e., phosphoric acid extraction system) to produce phosphoric acid, and then directly discharges the phosphogypsum after extraction into the first treatment system, removes soluble phosphorus, eutectic phosphorus, fluorine, organic matter and other impurities in the phosphogypsum in the first treatment system, so that the phosphogypsum treated by the squeezed steel pipe can be directly used in the construction field, and then the phosphogypsum can also be directly discharged into the second treatment system, and the heavy metals in the phosphogypsum are treated in the second treatment system, so that the treated phosphogypsum can be used as fertilizer in agricultural production, such as special fertilizer for saline-alkali land improvement and special fertilizer for heavy metal passivation. According to the different demand for finished products, the phosphogypsum treated by the first treatment system can also be discharged into the second treatment system, so that the content of each element in the phosphogypsum can be adjusted to a certain extent. Therefore, this system can not only efficiently process phosphogypsum and reduce its accumulation, but also treat phosphogypsum as a product rather than waste or by-product from the very beginning during the wet production of phosphoric acid. In addition, the various components in phosphogypsum can be fully utilized, thereby minimizing the additional pollutant emissions caused by the treatment of phosphogypsum. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic structural diagram of an efficient phosphogypsum processing system provided in an embodiment of the present invention.

[0016] Icons: 10-raw material tank, 11-extraction tank, 12-phosphoric acid storage tank, 21-water washing device, 22-first mixing device, 23-first storage tank, 31-second mixing device, 32-additive storage tank, 33-second storage tank. DETAILED DESCRIPTION

[0017] Example

[0018] The following is further described in conjunction with specific embodiments. Figure 1As shown (the arrows in the figure indicate the flow direction of the material), the phosphogypsum treatment system of this embodiment includes a phosphoric acid extraction system, a first treatment system connected to the waste discharge end of the phosphoric acid extraction system, and a second treatment system connected to the first treatment system; the waste outlet end of the phosphoric acid extraction system is connected to the second treatment system. Specifically, the production process of wet phosphoric acid (i.e., phosphoric acid extraction system) is used to produce phosphoric acid, and then the phosphogypsum after the extraction is directly discharged into the first treatment system, and the soluble phosphorus, eutectic phosphorus, fluorine, organic matter and other impurities in the phosphogypsum are removed in the first treatment system, so that the phosphogypsum treated by the squeezed steel pipe can be directly used in the construction field, and then the phosphogypsum can also be directly discharged into the second treatment system, and the heavy metals in the phosphogypsum are treated in the second treatment system, so that the treated phosphogypsum can be used as fertilizers in agricultural production, such as special fertilizers for saline-alkali land improvement and special fertilizers for heavy metal passivation. According to the different demand for finished products, the phosphogypsum treated by the first treatment system can also be discharged into the second treatment system, so that the content of each element in the phosphogypsum can be adjusted to a certain extent. Therefore, this system can not only efficiently process phosphogypsum and reduce its accumulation, but also treat phosphogypsum as a product rather than waste or by-product from the very beginning during the wet production of phosphoric acid. In addition, the various components in phosphogypsum can be fully utilized, thereby minimizing the additional pollutant emissions caused by the treatment of phosphogypsum.

[0019] The first treatment system in this embodiment includes a water washing device 21 connected to the phosphoric acid extraction system. The first treatment system also includes a first mixing device 22 connected to the discharge end of the water washing device 21, and the discharge end of the first mixing device 22 is connected to the feed end of the second treatment system. The first treatment system is mainly used to remove impurities such as soluble phosphorus, eutectic phosphorus, fluorine, and organic matter in phosphogypsum, and the present invention is treated by combining water washing + lime neutralization, but there are many known methods for treating phosphogypsum, so the first treatment system of the present invention can also use lime neutralization + ball milling, lime neutralization + flotation, lime neutralization + calcination, flotation + ball milling, acid leaching + water washing and other combined processes. Therefore, in this embodiment, the water washing device 21 is used to wash away phosphorus, fluorine and organic matter in the phosphogypsum, and then it is mixed with lime in the first mixing device 22, and the remaining impurities in the phosphogypsum are converted into precipitates by lime and filtered out. So that the final phosphogypsum can meet the standards of building gypsum.

[0020] The second treatment system in this embodiment includes a second mixing device 31, and the feed end of the second mixing device 31 is connected to the discharge end of the first mixing device 22. Specifically, the phosphogypsum can be used as building gypsum after passing through the first treatment system, and part or all of the phosphogypsum treated by the first treatment system can also be discharged into the second treatment system for further treatment. Therefore, the second mixing device 31 is mainly used to remove the remaining heavy metals in the phosphogypsum. In this embodiment, by adding kaolin, montmorillonite, etc. to the phosphogypsum (kaolin can be stored in the additive storage tank 32 as an additive), the heavy metal ions in the phosphogypsum can be chelated into the kaolin, montmorillonite, etc., to achieve in-situ treatment of the heavy metal ions. When the treated phosphogypsum can be used as a fertilizer in agriculture, the heavy metal ions therein will be released from it at an extremely slow rate. When the release rate of heavy metals is slow enough, it will not be harmful to the soil and crops. Therefore, the phosphogypsum obtained by this method has the value of being directly applied to agricultural production, and no excess waste is discharged in the process, so no waste of resources and environmental pollution are generated.

[0021] The waste discharge end of the washing device 21 in this embodiment is connected to the feed end of the second mixing device 31. The waste discharge end of the first mixing device 22 is connected to the feed end of the second mixing device 31. Specifically, the wastes such as phosphorus, fluorine, and organic matter discharged after being treated by the first treatment system can be directly discharged into the second mixing device 31 and used as agricultural fertilizers, thereby reducing the discharge of waste.

[0022] The waste discharge end of the phosphoric acid extraction system in this embodiment is connected to the feed end of the second mixing device 31. Specifically, the phosphogypsum produced after the production of phosphoric acid can be directly discharged into the second mixing device 31 for treatment without passing through the first treatment system. This is because the phosphorus, fluorine, aluminum, organic matter and other substances contained in the phosphogypsum are what the soil needs, so it only needs to remove the heavy metal ions to apply it in agriculture. The amount of phosphogypsum discharged into the first treatment system and the second system can be adjusted according to actual market demand. And according to actual needs, different proportions of waste treated by the first treatment system can be added to the second mixing device 31 to achieve the purpose of adjusting the content of each element in the phosphogypsum.

[0023] The phosphoric acid extraction system in this embodiment includes a plurality of raw material tanks 10, an extraction tank 11 connected to the raw material tank 10, and a phosphoric acid storage tank 12 connected to the extraction tank 11; the waste material discharge end of the extraction tank 11 is connected to the first processing system. Specifically, the raw material tank 10 is mainly used to store raw materials such as phosphate rock and sulfuric acid.

[0024] In this embodiment, a first storage tank 23 connected to the discharge end of the first mixing device 22 is further included. A second storage tank 33 connected to the discharge end of the second mixing device 31 is further included. Specifically, the first storage tank 23 is mainly used to store phosphogypsum that can be used for construction after passing through the first treatment system, and the second storage tank 33 is used to store phosphogypsum that can be used for agriculture after passing through the second treatment system.

[0025] The technical solution of the embodiment of the present invention has at least the following advantages and beneficial effects: the efficient phosphogypsum treatment system of the present invention uses the production process of wet phosphoric acid (i.e., phosphoric acid extraction system) to produce phosphoric acid, and then directly discharges the phosphogypsum after extraction into the first treatment system, removes soluble phosphorus, eutectic phosphorus, fluorine, organic matter and other impurities in the phosphogypsum in the first treatment system, so that the phosphogypsum treated by the squeezed steel pipe can be directly used in the construction field, and then the phosphogypsum can also be directly discharged into the second treatment system, and the heavy metals in the phosphogypsum are treated in the second treatment system, so that the treated phosphogypsum can be used as fertilizer in agricultural production, such as special fertilizer for saline-alkali land improvement and special fertilizer for heavy metal passivation. According to the different demand for finished products, the phosphogypsum treated by the first treatment system can also be discharged into the second treatment system, so that the content of each element in the phosphogypsum can be adjusted to a certain extent. Therefore, this system can not only efficiently process phosphogypsum and reduce its accumulation, but also treat phosphogypsum as a product rather than waste or by-product from the very beginning during the wet production of phosphoric acid. In addition, the various components in phosphogypsum can be fully utilized, thereby minimizing the additional pollutant emissions caused by the treatment of phosphogypsum.

[0026] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An efficient phosphogypsum processing system, characterized by: It includes a phosphoric acid extraction system, a first treatment system and a second treatment system; The phosphoric acid extraction system is used to extract phosphoric acid and phosphogypsum; The first treatment system comprises a water washing device (21) and a first mixing device (22), wherein: the water washing device (21) is connected to the phosphoric acid extraction system and is used to wash away phosphorus, fluorine and organic matter in the phosphogypsum; the first mixing device (22) is connected to the discharge end of the water washing device (21), the washed phosphogypsum is mixed with lime in the first mixing device (22), and the remaining impurities in the phosphogypsum are converted into precipitates by the lime and filtered out, so that the phosphogypsum meets the standards of building gypsum; the second treatment system comprises a second mixing device (31) whose feed end is connected to the discharge end of the first mixing device (22), and the second mixing device (31) is connected to an additive storage tank (32) for storing kaolin; the second mixing device (31) is used to pass part of the phosphogypsum treated by the first mixing device and pass kaolin into the mixture, so as to achieve in-situ treatment of heavy metal ions in the phosphogypsum, so that the phosphogypsum can be used as a fertilizer in agriculture; The feed end of the second mixing device (31) is also connected to the waste discharge end of the water washing device (21) and the waste discharge end of the first mixing device (22) for introducing the waste discharged from the first treatment system to adjust the content of each element in the phosphogypsum.

2. The efficient phosphogypsum treatment system according to claim 1, characterized in that: The waste material discharge end of the phosphoric acid extraction system is connected to the feed end of the second mixing device.

3. The efficient phosphogypsum treatment system according to claim 1, characterized in that: The phosphoric acid extraction system comprises a plurality of raw material tanks, an extraction tank connected to the raw material tanks, and a phosphoric acid storage tank connected to the extraction tank; the waste material discharge end of the extraction tank is connected to the first processing system.

4. The efficient phosphogypsum treatment system according to claim 1, characterized in that: Also included is a first storage tank connected to the discharge end of the first mixing device.

5. The efficient phosphogypsum treatment system according to claim 1, characterized in that: Also included is a second storage tank connected to the discharge end of the second mixing device.

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