A stripping flotation device and method for removing mixed extractants and carbon silicon impurities in the post-treatment process of phosphogypsum

Abstract

The present invention provides a stripping flotation device and method for removing mixed extractants and carbon-silicon impurities in the post-treatment process of phosphogypsum, wherein the stripping flotation device comprises a sedimentation separation unit and a bubble generating unit; the sedimentation separation unit comprises a thickener and a single-layer stirring paddle arranged inside the thickener; the side wall of the thickener is provided with an organic phase overflow port, and the bottom is provided with a slurry discharge port and at least two air inlets; the bubble generating unit is connected to each air inlet. The method is to pre-separate a three-phase mixed slurry of an extractant, phosphoric acid, and phosphogypsum to obtain an organic phase of the extractant and a solid-liquid mixed phase of phosphoric acid and phosphogypsum; the pre-separation process is accompanied by stripping flotation treatment. The present invention significantly reduces the entrainment of the organic phase extractant, realizes the efficient removal of carbon-silicon impurities, improves the processing efficiency, and reduces the production cost.

Description

Technical Field

[0001] The invention belongs to the technical field of phosphorus chemical industry, and relates to a stripping flotation device, in particular to a stripping flotation device and method for removing mixed extractants and carbon silicon impurities in a post-treatment process of phosphogypsum. Background Art

[0002] Most of my country's phosphate mines are medium- and low-grade phosphate mines with high impurity content. During the preparation of wet phosphoric acid, some impurities will dissolve into the liquid phase, affecting the quality of phosphoric acid. In addition, undissolved impurities will affect the crystal form and quality of calcium sulfate, and thus affect the comprehensive application of phosphogypsum. Therefore, coupling the impurity removal process in the acid hydrolysis process of wet phosphoric acid plays a significant role in improving the quality of phosphoric acid and phosphogypsum, and the design and establishment of the corresponding system in this process is crucial to improving the overall quality of the product.

[0003] During the acid hydrolysis of phosphate rock, after controlled acid hydrolysis using a synergistic extraction method for impurities, the acid, phosphogypsum and organic extract are mixed. How to achieve the entrainment of the organic phase extractant in the post-treatment process of the phosphogypsum and the steam stripping separation of carbon and silicon is the key to reducing the overall process cost.

[0004] It can be seen that how to provide a device and method for the post-treatment process of phosphogypsum, reduce the entrainment of the organic phase extractant, achieve the removal of carbon and silicon impurities, improve the processing efficiency, and reduce production costs has become an urgent problem that technical personnel in this field need to solve. Summary of the invention

[0005] The object of the present invention is to provide a steam stripping flotation device and method for removing entrained extractants and carbon-silicon impurities in the post-treatment process of phosphogypsum, the method significantly reduces the entrainment amount of the organic phase extractant, achieves efficient removal of carbon-silicon impurities, improves treatment efficiency, and reduces production costs.

[0006] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a stripping flotation device for removing entrained extractants and carbon-silicon impurities in a post-treatment process of phosphogypsum, wherein the stripping flotation device comprises a sedimentation separation unit and a bubble generating unit.

[0008] The sedimentation separation unit includes a thickener and a single-layer stirring paddle arranged inside the thickener.

[0009] The side wall of the thickener is provided with an organic phase overflow port, and the bottom is provided with a slurry discharge port and at least two air inlets, for example, 2, 3, 4, 5 or 6, but are not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0010] The bubble generating unit is connected to each air inlet.

[0011] In the present invention, the sedimentation separation unit is used for rapid pre-separation of the extractant, phosphoric acid and phosphogypsum to obtain an organic phase and a solid-liquid mixed phase. The organic phase is returned to the stripping system of the reaction process; the solid-liquid mixed phase enters the subsequent solid-liquid separation unit for solid-liquid separation to obtain phosphoric acid and phosphogypsum.

[0012] In the present invention, the bubble generating unit is used to blow bubbles into the sedimentation separation unit, and the entrained tiny organic droplets and carbon silicon impurities are brought to the upper layer of the slurry through the stripping flotation effect, thereby achieving the synergistic removal of the extractant and carbon silicon impurities.

[0013] Preferably, the bubble generating unit comprises a micro-nano bubble generator.

[0014] The present invention utilizes the micro-nano bubble generator to process process water, thereby preparing process water containing a large number of micro-nano bubbles, which is subsequently transported to a sedimentation separation unit for stripping flotation.

[0015] Preferably, the thickener comprises a cylindrical side wall and a conical bottom.

[0016] Preferably, the ratio of the overall height of the thickener to the diameter of the cylindrical side wall is (1-10):1, for example, it can be 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1 or 10:1, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0017] In the present invention, the ratio of the overall height of the thickener to the diameter of the cylindrical side wall has a significant effect on the separation efficiency of the sedimentation separation unit. When the ratio is less than 1:1, the cross-section of the thickener is large, while the height is relatively low, and the three-phase substances in the slurry cannot be fully separated during the sedimentation process; when the ratio is greater than 10:1, the height of the thickener is too high, which not only increases the equipment cost, but also occupies a large space.

[0018] In the present invention, the overall height of the thickener is the sum of the height of the cylindrical side wall and the height of the conical bottom.

[0019] Preferably, the cone angle of the conical bottom is 120-150°, for example, it can be 120°, 125°, 130°, 135°, 140°, 145° or 150°, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0020] Preferably, the material inlet of the thickener is arranged at 1 / 2-3 / 4 of the overall height of the thickener, for example, 1 / 2, 3 / 5, 2 / 3, 7 / 10 or 3 / 4, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0021] In the present invention, the material inlet of the thickener is arranged at 1 / 2-3 / 4 of the overall height of the thickener, which can significantly reduce phase disturbance, achieve rapid separation of the organic phase and the solid-liquid mixed phase, reduce mutual entrainment between the two phases, and thus improve phase separation efficiency.

[0022] Preferably, the single-layer stirring paddle comprises an anchor-type stirring paddle or a rake-type stirring paddle.

[0023] In the present invention, due to the use of a micro-nano bubble generator, the entrainment of the organic phase in the solid-liquid mixed phase is significantly reduced, and the removal of carbon and silicon impurities is achieved simultaneously. Therefore, only a single-layer stirring paddle is needed in the thickener to achieve sufficient washing of the phosphogypsum, which simplifies the stirring form, reduces the production cost and improves the separation efficiency.

[0024] Preferably, the stripping flotation device further comprises a premixing unit and a solid-liquid separation unit.

[0025] Preferably, the material outlet of the premixing unit is connected to the material inlet of the thickener.

[0026] Preferably, the solid-liquid separation unit is connected to the slurry discharge port of the thickener.

[0027] Preferably, the premixing unit comprises a premixing tank.

[0028] Preferably, the solid-liquid separation unit comprises a filtering-washing device.

[0029] In the present invention, the premixing unit is used to fully mix process water and the phosphogypsum filter cake obtained from the reaction system to obtain a three-phase mixed slurry of extractant, phosphoric acid and phosphogypsum; the solid-liquid separation unit is used to separate the solid-liquid mixed phase of phosphoric acid and phosphogypsum.

[0030] In a second aspect, the present invention provides a method for removing mixed extractants and carbon-silicon impurities in a post-treatment process of phosphogypsum using a stripping flotation device as described in the first aspect, wherein the method comprises pre-separating a three-phase mixed slurry of extractant, phosphoric acid, and phosphogypsum to obtain an organic phase of the extractant and a solid-liquid mixed phase of phosphoric acid and phosphogypsum; the pre-separation process is accompanied by stripping flotation treatment.

[0031] The present invention accompanies the stripping flotation treatment in the pre-separation stage of the three-phase mixed slurry, and utilizes the emulsification effect to more significantly reduce the entrainment amount of the organic phase in the solid-liquid mixed phase, and simultaneously realizes the efficient removal of carbon and silicon impurities, further improving the quality of phosphogypsum.

[0032] Preferably, the stripping flotation treatment is carried out using micro-nano bubble flotation technology.

[0033] In the present invention, the micro-nano bubble flotation technology is to accelerate the process water and air through a high-speed vortex to form a gas-liquid mixed liquid. During the acceleration process, high pressure is formed inside the liquid, and bubbles with larger particle sizes are compressed to form nano-sized bubbles. Such bubbles have very high energy and can produce local ionization on water after being injected into the water. After stabilization, a layer of positive and negative ions surrounds some of the bubbles, so that the bubbles have a charging function. Since the micro-nano bubbles are very small, they have the surface energy of any tiny particles of an object, and have a surface adsorption effect on other objects. In addition, the charging function of some bubbles, the entrained tiny organic droplets and carbon and silicon impurities can be brought to the upper layer of the slurry through the micro-nano bubble flotation effect, thereby realizing the synergistic removal of the extractant and the carbon and silicon impurities.

[0034] Preferably, the method further comprises a premixing process.

[0035] Preferably, the premixing treatment is specifically mixing process water and phosphogypsum filter cake.

[0036] Preferably, the mixing mass ratio of the process water and the phosphogypsum filter cake is (0.2-5):1, for example, it can be 0.2:1, 0.4:1, 0.6:1, 0.8:1, 1:1, 2:1, 3:1, 4:1 or 5:1, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0037] Preferably, the solid-liquid mixed phase is subsequently subjected to solid-liquid separation.

[0038] As a preferred technical solution of the second aspect of the present invention, the method is to mix process water and phosphogypsum filter cake in a mass ratio of (0.2-5):1, and pre-separate the three-phase mixed slurry of extractant, phosphoric acid and phosphogypsum obtained by premixing to obtain an organic phase of the extractant and a solid-liquid mixed phase of phosphoric acid and phosphogypsum, and the obtained solid-liquid mixed phase is subsequently subjected to solid-liquid separation; the pre-separation process is accompanied by steam stripping flotation treatment, and the steam stripping flotation treatment is carried out using micro-nano bubble flotation technology.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] (1) The method provided by the present invention adds a stripping flotation operation during the post-treatment of phosphogypsum, which significantly reduces the entrainment of the organic phase extractant, and can be reduced to 0.001wt% at the lowest, achieving efficient removal of carbon and silicon impurities. The whiteness of the obtained phosphogypsum can reach up to 84.1%, thereby improving the treatment efficiency and reducing the production cost;

[0041] (2) The device provided by the present invention appropriately increases the height-to-diameter ratio of the sedimentation separation unit on the basis of traditional equipment, and adopts a micro-nano bubble generator to improve the separation efficiency, simplify the form of the stirring paddle, reduce the equipment cost, and has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 is a schematic structural diagram of the steam stripping flotation device provided in Examples 1-5;

[0043] Figure 2 This is a schematic diagram of the device structure provided in Example 1.

[0044] Among them: 10-sedimentation separation unit; 11-thickener; 12-single-layer stirring paddle; 20-bubble generating unit; 30-premixing unit; 40-solid-liquid separation unit. DETAILED DESCRIPTION

[0045] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only used to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0046] Example 1

[0047] This embodiment provides a stripping flotation device for removing the impurities of the extractant and carbon silicon impurities in the post-treatment process of phosphogypsum. Figure 1 As shown, the steam stripping flotation device includes a sedimentation separation unit 10 and a bubble generating unit 20; the sedimentation separation unit 10 includes a thickener 11 and a single-layer stirring paddle 12 arranged inside the thickener 11, the side wall of the thickener 11 is provided with an organic phase overflow port, and the bottom is provided with a slurry discharge port and two air inlets; the bubble generating unit 20 is a ZJN-NM-06 micro-nano bubble generator produced by Shanghai Zhongjing Environmental Protection Technology Co., Ltd.

[0048] In this embodiment, the thickener 11 includes a cylindrical side wall and a conical bottom. The ratio of the overall height of the thickener 11 to the diameter of the cylindrical side wall is 5:1. The cone angle of the conical bottom is 135°. The material inlet of the thickener 11 is set at 2 / 3 of the overall height of the thickener 11. The single-layer stirring paddle 12 includes an anchor stirring paddle.

[0049] In this embodiment, the steam stripping flotation device also includes a premixing unit 30 and a solid-liquid separation unit 40, the material outlet of the premixing unit 30 is connected to the material inlet of the thickener 11, and the solid-liquid separation unit 40 is connected to the slurry discharge port of the thickener 11; the premixing unit 30 is a premixing tank, and the solid-liquid separation unit 40 is a filtering-washing integrated machine.

[0050] Example 2

[0051] This embodiment provides a stripping flotation device for removing the impurities of the extractant and carbon silicon impurities in the post-treatment process of phosphogypsum. Figure 1 As shown, the steam stripping flotation device includes a sedimentation separation unit 10 and a bubble generating unit 20; the sedimentation separation unit 10 includes a thickener 11 and a single-layer stirring paddle 12 arranged inside the thickener 11, the side wall of the thickener 11 is provided with an organic phase overflow port, and the bottom is provided with a slurry discharge port and two air inlets; the bubble generating unit 20 is a ZJN-NM-06 micro-nano bubble generator produced by Shanghai Zhongjing Environmental Protection Technology Co., Ltd.

[0052] In this embodiment, the thickener 11 includes a cylindrical side wall and a conical bottom. The ratio of the overall height of the thickener 11 to the diameter of the cylindrical side wall is 1:1. The cone angle of the conical bottom is 150°. The material inlet of the thickener 11 is set at 1 / 2 of the overall height of the thickener 11. The single-layer stirring paddle 12 includes a rake-type stirring paddle.

[0053] In this embodiment, the steam stripping flotation device also includes a premixing unit 30 and a solid-liquid separation unit 40, the material outlet of the premixing unit 30 is connected to the material inlet of the thickener 11, and the solid-liquid separation unit 40 is connected to the slurry discharge port of the thickener 11; the premixing unit 30 is a premixing tank, and the solid-liquid separation unit 40 is a filtering-washing integrated machine.

[0054] Example 3

[0055] This embodiment provides a stripping flotation device for removing the impurities of the extractant and carbon silicon impurities in the post-treatment process of phosphogypsum. Figure 1 As shown, the steam stripping flotation device includes a sedimentation separation unit 10 and a bubble generating unit 20; the sedimentation separation unit 10 includes a thickener 11 and a single-layer stirring paddle 12 arranged inside the thickener 11, the side wall of the thickener 11 is provided with an organic phase overflow port, and the bottom is provided with a slurry discharge port and two air inlets; the bubble generating unit 20 is a ZJN-NM-06 micro-nano bubble generator produced by Shanghai Zhongjing Environmental Protection Technology Co., Ltd.

[0056] In this embodiment, the thickener 11 includes a cylindrical side wall and a conical bottom. The ratio of the overall height of the thickener 11 to the diameter of the cylindrical side wall is 10:1. The cone angle of the conical bottom is 120°. The material inlet of the thickener 11 is set at 3 / 4 of the overall height of the thickener 11. The single-layer stirring paddle 12 includes an anchor stirring paddle.

[0057] In this embodiment, the steam stripping flotation device also includes a premixing unit 30 and a solid-liquid separation unit 40, the material outlet of the premixing unit 30 is connected to the material inlet of the thickener 11, and the solid-liquid separation unit 40 is connected to the slurry discharge port of the thickener 11; the premixing unit 30 is a premixing tank, and the solid-liquid separation unit 40 is a filtering-washing integrated machine.

[0058] Example 4

[0059] This embodiment provides a stripping flotation device for removing the impurities of the extractant and carbon silicon impurities in the post-treatment process of phosphogypsum. Figure 1 As shown, in the stripping flotation device, except that the ratio of the overall height of the thickener 11 to the diameter of the cylindrical side wall is 0.75:1, the remaining structures and conditions are the same as those in Example 1, so they are not described here.

[0060] Example 5

[0061] This embodiment provides a stripping flotation device for removing the impurities of the extractant and carbon silicon impurities in the post-treatment process of phosphogypsum. Figure 1 As shown, in the stripping flotation device, except that the ratio of the overall height of the thickener 11 to the diameter of the cylindrical side wall is 12:1, the remaining structures and conditions are the same as those in Example 1, so they are not described here in detail.

[0062] Comparative Example 1

[0063] This comparative example provides a device for removing the impure extractant in the post-treatment process of phosphogypsum, such as Figure 2 As shown, the device includes a sedimentation separation unit 10; the sedimentation separation unit 10 includes a thickener 11 and a single-layer stirring paddle 12 arranged inside the thickener 11, the side wall of the thickener 11 is provided with an organic phase overflow port, and the bottom is provided with a slurry discharge port and two air inlets.

[0064] In this comparative example, the thickener 11 includes a cylindrical side wall and a conical bottom. The ratio of the overall height of the thickener 11 to the diameter of the cylindrical side wall is 5:1. The cone angle of the conical bottom is 135°. The material inlet of the thickener 11 is arranged at 2 / 3 of the overall height of the thickener 11. The single-layer agitator 12 includes an anchor agitator.

[0065] In this comparative example, the device also includes a premixing unit 30 and a solid-liquid separation unit 40, the material outlet of the premixing unit 30 is connected to the material inlet of the thickener 11, and the solid-liquid separation unit 40 is connected to the slurry discharge port of the thickener 11; the premixing unit 30 is a premixing tank, and the solid-liquid separation unit 40 is a filtering-washing integrated machine.

[0066] Application Example 1

[0067] This application example uses the stripping flotation device provided in Example 1 to carry out the post-treatment process of phosphogypsum to remove the mixed extractant and carbon silicon impurities. The specific process is: the process water and the phosphogypsum filter cake are mixed in the premixing tank at a mass ratio of 2.5:1, and the three-phase mixed slurry of the premixed extractant, phosphoric acid and phosphogypsum is transported to the thickener 11 for pre-separation to obtain the organic phase of the extractant and the solid-liquid mixed phase of phosphoric acid and phosphogypsum, and the obtained solid-liquid mixed phase is subsequently subjected to solid-liquid separation in a filtering-washing integrated machine; the pre-separation process is accompanied by stripping flotation treatment, and the gas-liquid mixed liquid required for the stripping flotation treatment is prepared in the ZJN-NM-06 micro-nano bubble generator.

[0068] The entrainment amount of the organic phase extractant in the solid-liquid mixed phase of this application example is 0.005wt%, and the whiteness of the obtained phosphogypsum is 82.9%.

[0069] Application Example 2

[0070] This application example uses the stripping flotation device provided in Example 2 to carry out the post-treatment process of phosphogypsum to remove the mixed extractant and carbon silicon impurities. The specific process is: the process water and the phosphogypsum filter cake are mixed in the premixing tank at a mass ratio of 0.2:1, and the three-phase mixed slurry of the premixed extractant, phosphoric acid and phosphogypsum is transported to the thickener 11 for pre-separation to obtain the organic phase of the extractant and the solid-liquid mixed phase of phosphoric acid and phosphogypsum, and the obtained solid-liquid mixed phase is subsequently subjected to solid-liquid separation in a filtering-washing integrated machine; the pre-separation process is accompanied by stripping flotation treatment, and the gas-liquid mixed liquid required for the stripping flotation treatment is prepared in the ZJN-NM-06 micro-nano bubble generator.

[0071] The entrainment amount of the organic phase extractant in the solid-liquid mixed phase of this application example is 0.03wt%, and the whiteness of the obtained phosphogypsum is 75.3%.

[0072] Application Example 3

[0073] This application example uses the stripping flotation device provided in Example 3 to carry out the post-treatment process of phosphogypsum to remove the mixed extractant and carbon silicon impurities. The specific process is: the process water and the phosphogypsum filter cake are mixed in the premixing tank at a mass ratio of 5:1, and the three-phase mixed slurry of the premixed extractant, phosphoric acid and phosphogypsum is transported to the thickener 11 for pre-separation to obtain the organic phase of the extractant and the solid-liquid mixed phase of phosphoric acid and phosphogypsum, and the obtained solid-liquid mixed phase is subsequently subjected to solid-liquid separation in a filtering-washing integrated machine; the pre-separation process is accompanied by stripping flotation treatment, and the gas-liquid mixed liquid required for the stripping flotation treatment is prepared in the ZJN-NM-06 micro-nano bubble generator.

[0074] The entrainment amount of the organic phase extractant in the solid-liquid mixed phase of this application example is 0.001wt%, and the whiteness of the obtained phosphogypsum is 84.1%.

[0075] Application Example 4

[0076] This application example uses the stripping flotation device provided in Example 4 to carry out the post-treatment process of phosphogypsum to remove the mixed extractant and carbon silicon impurities. The specific process is: the process water and the phosphogypsum filter cake are mixed in the premixing tank at a mass ratio of 2.5:1, and the three-phase mixed slurry of the premixed extractant, phosphoric acid and phosphogypsum is transported to the thickener 11 for pre-separation to obtain the organic phase of the extractant and the solid-liquid mixed phase of phosphoric acid and phosphogypsum, and the obtained solid-liquid mixed phase is subsequently subjected to solid-liquid separation in a filtering-washing integrated machine; the pre-separation process is accompanied by stripping flotation treatment, and the gas-liquid mixed liquid required for the stripping flotation treatment is prepared in the ZJN-NM-06 micro-nano bubble generator.

[0077] The entrainment amount of the organic phase extractant in the solid-liquid mixed phase of this application example is 0.1wt%, and the whiteness of the obtained phosphogypsum is 65.5%.

[0078] Compared with Application Example 1, the entrainment amount of the organic phase in the solid-liquid mixed phase of this application example is increased, and the whiteness of the obtained phosphogypsum is reduced, indicating that the height-to-diameter ratio of the thickener in Example 4 is less than 1:1, which will cause the three-phase materials in the slurry to be unable to be fully separated during the sedimentation process, thereby reducing the separation efficiency.

[0079] Application Example 5

[0080] This application example uses the stripping flotation device provided in Example 5 to carry out the post-treatment process of phosphogypsum to remove the mixed extractant and carbon silicon impurities. The specific process is: the process water and the phosphogypsum filter cake are mixed in the premixing tank at a mass ratio of 2.5:1, and the three-phase mixed slurry of the premixed extractant, phosphoric acid and phosphogypsum is transported to the thickener 11 for pre-separation to obtain the organic phase of the extractant and the solid-liquid mixed phase of phosphoric acid and phosphogypsum, and the obtained solid-liquid mixed phase is subsequently subjected to solid-liquid separation in a filtering-washing integrated machine; the pre-separation process is accompanied by stripping flotation treatment, and the gas-liquid mixed liquid required for the stripping flotation treatment is prepared in the ZJN-NM-06 micro-nano bubble generator.

[0081] The entrainment amount of the organic phase extractant in the solid-liquid mixed phase of this application example is 0.005wt%, and the whiteness of the obtained phosphogypsum is 82.3%.

[0082] Compared with Application Example 1, the entrainment amount of the organic phase in the solid-liquid mixed phase and the whiteness of the obtained phosphogypsum in this application example did not show obvious improvement. However, the height-to-diameter ratio of the thickener in Example 5 is greater than 10:1, which not only increases the equipment cost, but also occupies a large space.

[0083] Comparative application example 1

[0084] This comparative application example uses the device provided in comparative example 1 to carry out the post-treatment process of phosphogypsum to remove the mixed extractant. The specific process is: the process water and the phosphogypsum filter cake are mixed in the premixing tank at a mass ratio of 2.5:1, and the three-phase mixed slurry of the premixed extractant, phosphoric acid and phosphogypsum is transported to the thickener 11 for pre-separation to obtain the organic phase of the extractant and the solid-liquid mixed phase of phosphoric acid and phosphogypsum, and the obtained solid-liquid mixed phase is subsequently subjected to solid-liquid separation in a filtering-washing integrated machine.

[0085] The entrainment amount of the organic phase extractant in the solid-liquid mixed phase of this comparative application example is 0.2wt%, and the whiteness of the obtained phosphogypsum is 60.3%.

[0086] Compared with Application Example 1, the entrainment amount of organic phase in the solid-liquid mixed phase of this comparative application example is significantly increased, and the whiteness of the obtained phosphogypsum is significantly reduced. This is because Comparative Example 1 removes the bubble generating unit on the basis of Example 1, that is, no steam stripping flotation operation is performed, which leads to more organic phase extractant and carbon silicon impurities being mixed in the solid-liquid mixed phase.

[0087] It can be seen that the method provided by the present invention adds steam stripping flotation operation during the post-treatment of phosphogypsum, which significantly reduces the entrainment of the organic phase extractant, and can be reduced to a minimum of 0.001wt%, achieving efficient removal of carbon and silicon impurities, and the whiteness of the obtained phosphogypsum can reach up to 84.1%, thereby improving the treatment efficiency and reducing the production cost; in addition, the device provided by the present invention appropriately increases the height-to-diameter ratio of the sedimentation separation unit on the basis of traditional equipment, and adopts a micro-nano bubble generator to improve the separation efficiency, simplify the form of the stirring paddle, reduce the equipment cost, and has good application prospects.

[0088] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A stripping flotation device for removing impurities such as extractants and carbon and silicon impurities in the post-treatment process of phosphogypsum, characterized in that: The stripping flotation device comprises a sedimentation separation unit and a bubble generating unit; The sedimentation separation unit includes a thickener and a single-layer stirring paddle arranged inside the thickener; The thickener is provided with an organic phase overflow port on the side wall, a slurry discharge port and at least two air inlets on the bottom; The bubble generating unit is connected to each air inlet; The bubble generating unit comprises a micro-nano bubble generator; The thickener comprises a cylindrical side wall and a conical bottom; The ratio of the overall height of the thickener to the diameter of the cylindrical side wall is (1-10):1; The cone angle of the conical bottom is 120-150°; The material inlet of the thickener is arranged at 1 / 2-3 / 4 of the overall height of the thickener.

2. The stripping flotation device according to claim 1, characterized in that: The single-layer stirring paddle includes an anchor-type stirring paddle or a rake-type stirring paddle.

3. The stripping flotation device according to claim 1, characterized in that: The stripping flotation device further comprises a premixing unit and a solid-liquid separation unit.

4. The steam stripping flotation device according to claim 3, characterized in that: The material outlet of the premixing unit is connected to the material inlet of the thickener.

5. The steam stripping flotation device according to claim 3, characterized in that: The solid-liquid separation unit is connected to the slurry discharge port of the thickener.

6. The stripping flotation device according to claim 3, characterized in that: The premixing unit includes a premixing tank.

7. The stripping flotation device according to claim 3, characterized in that: The solid-liquid separation unit includes a filtering-washing device.

8. A method for removing the inclusion of extractants and carbon-silicon impurities in the post-treatment process of phosphogypsum using the stripping flotation device according to any one of claims 1 to 7, characterized in that: The method comprises pre-separating a three-phase mixed slurry of an extractant, phosphoric acid and phosphogypsum to obtain an organic phase of the extractant and a solid-liquid mixed phase of phosphoric acid and phosphogypsum; The pre-separation process is accompanied by stripping flotation treatment; The stripping flotation treatment is carried out using micro-nano bubble flotation technology.

9. The method according to claim 8, characterized in that The method further comprises a premixing process.

10. The method according to claim 9, characterized in that The premixing treatment specifically includes mixing process water and phosphogypsum filter cake.

11. The method according to claim 10, characterized in that The mixing mass ratio of the process water and the phosphogypsum filter cake is (0.2-5):

1.

12. The method according to claim 8, characterized in that The solid-liquid mixed phase is subsequently subjected to solid-liquid separation.

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