阅读说明：本技术 一种用于萃取剂、磷酸、磷石膏三相分离及协同脱碳脱硅的装置与方法 (Device and method for three-phase separation and synergistic decarburization and desilication of extracting agent, phosphoric acid and phosphogypsum ) 是由 李会泉 朱干宇 李少鹏 于 2021-04-19 设计创作，主要内容包括：本发明提供一种用于萃取剂、磷酸、磷石膏三相分离及协同脱碳脱硅的装置与方法,所述装置包括沉降分离单元、反萃循环单元和固液分离单元；所述沉降分离单元包括浓密机和设置在所述浓密机内部的双层搅拌系统；所述反萃循环单元与有机相溢流口连接；所述固液分离单元与浆液出料口连接。所述方法包括以下步骤：(1)将萃取剂、磷酸、磷石膏的三相混合浆液进行预分离,得到萃取剂的有机相和磷酸与磷石膏的固液混合相；(2)将步骤(1)所得有机相进行反萃处理,得到循环萃取剂；(3)将步骤(1)所得固液混合相进行固液分离,得到磷酸和磷石膏。本发明实现了萃取剂、磷酸和磷石膏的高效分离,且提升了磷石膏的质量,有利于大规模推广应用。(The invention provides a device and a method for three-phase separation and synergistic decarburization and desilication of an extracting agent, phosphoric acid and phosphogypsum, wherein the device comprises a settlement separation unit, a back extraction circulation unit and a solid-liquid separation unit; the sedimentation separation unit comprises a thickener and a double-layer stirring system arranged in the thickener; the back extraction circulating unit is connected with an organic phase overflow port; the solid-liquid separation unit is connected with the slurry discharge port. The method comprises the following steps: (1) pre-separating the three-phase mixed slurry of the extracting agent, the phosphoric acid and the phosphogypsum to obtain an organic phase of the extracting agent and a solid-liquid mixed phase of the phosphoric acid and the phosphogypsum; (2) carrying out back extraction treatment on the organic phase obtained in the step (1) to obtain a circulating extractant; (3) and (3) carrying out solid-liquid separation on the solid-liquid mixed phase obtained in the step (1) to obtain phosphoric acid and phosphogypsum. The invention realizes the high-efficiency separation of the extracting agent, the phosphoric acid and the phosphogypsum, improves the quality of the phosphogypsum and is beneficial to large-scale popularization and application.)

1. The device for three-phase separation and synergetic decarburization and desilication of the extractant, the phosphoric acid and the phosphogypsum is characterized by comprising a settlement separation unit, a back extraction circulation unit and a solid-liquid separation unit;

the sedimentation separation unit comprises a thickener and a double-layer stirring system arranged in the thickener;

the side wall of the thickener is provided with 1 organic phase overflow port, and the bottom of the thickener is provided with 1 slurry discharge port and at least 2 air blowing ports;

the back extraction circulating unit is connected with an organic phase overflow port;

the solid-liquid separation unit is connected with the slurry discharge port.

2. The apparatus of claim 1, wherein the thickener comprises a cylindrical sidewall and a conical bottom;

preferably, the ratio of the overall height of the thickener to the diameter of the cylindrical sidewall is (1-10): 1;

preferably, the conical angle of the conical bottom is 120-150 °;

preferably, the material inlet of the thickener is arranged at the junction of phase interfaces in the thickener;

preferably, the phase interface junction is located at 1/3-2/3 of the overall height of the thickener.

3. The apparatus of claim 1 or 2, wherein the double layer stirring system comprises a plug flow type stirring paddle and an anchor type stirring paddle on the same stirring rod;

preferably, the plug flow type stirring paddle is arranged in an organic phase area of the thickener;

preferably, the anchor type stirring paddle is arranged in a solid-liquid mixed phase area of the thickener.

4. The apparatus according to any one of claims 1 to 3, wherein the lower edge of the organic phase overflow port is arranged in the organic phase region of the thickener;

preferably, the distance between the lower edge of the overflow port of the organic phase and the liquid level of the organic phase is 1/5-1/4 of the height of the organic phase region.

5. The apparatus of any one of claims 1-4, wherein the distance between the center point of the air blowing opening and the central axis of the thickener is 1/4-3/4 of the radius of the cylindrical sidewall;

preferably, the included angle between the central line of the air blowing opening and the central axis of the thickener is 10-45 degrees.

6. The apparatus according to any one of claims 1 to 5, wherein the stripping circulation unit comprises a particle filtering device and an impurity stripping system which are connected in sequence;

preferably, the particle filtering device is connected with an organic phase overflow port;

preferably, the impurity stripping system comprises a stripping column.

7. The apparatus according to any one of claims 1-6, wherein the solid-liquid separation unit comprises a filtration-washing apparatus.

8. A method for carrying out three-phase separation of an extracting agent, phosphoric acid and phosphogypsum and synergistic decarburization and desilication by using the device as defined in any one of claims 1 to 7, which is characterized by comprising the following steps:

(1) pre-separating the three-phase mixed slurry of the extracting agent, the phosphoric acid and the phosphogypsum to obtain an organic phase of the extracting agent and a solid-liquid mixed phase of the phosphoric acid and the phosphogypsum;

(2) carrying out back extraction treatment on the organic phase obtained in the step (1) to obtain a circulating extractant;

(3) carrying out solid-liquid separation on the solid-liquid mixed phase obtained in the step (1) to obtain phosphoric acid and phosphogypsum;

wherein, the steps (2) and (3) are not in sequence.

9. The method of claim 8, wherein said pre-separating of step (1) is accompanied by agitation and air blowing;

preferably, the rotation speed of the stirring is 10-200 rpm;

preferably, the air blowing speed is 0.1-50L/min.

10. The method according to claim 8 or 9, characterized in that the back extraction treatment of the step (2) is further subjected to solid-liquid separation;

preferably, the solid-liquid separation in step (3) is further followed by a washing treatment.

Technical Field

The invention belongs to the technical field of phosphorus chemical industry, relates to a three-phase separation device, and particularly relates to a device and a method for three-phase separation and collaborative decarburization and desilication of an extracting agent, phosphoric acid and phosphogypsum.

Background

The phosphoric chemical products are widely applied to producing fertilizers and composite functional materials containing phosphorus, while the preparation of wet-process phosphoric acid is an important component of the phosphorus chemical industry and is the most basic process for preparing downstream products of the phosphorus chemical industry, and the main process is to decompose phosphorite by adopting sulfuric acid to obtain phosphoric acid and phosphogypsum (solid-phase calcium sulfate). However, most of phosphorite in China is medium-low grade phosphorite, the impurity content is high, and in the preparation process of wet-process phosphoric acid, part of impurities can be dissolved into a liquid phase to influence the quality of the phosphoric acid; in addition, undissolved impurities can affect the crystal form and quality of calcium sulfate, and further affect the comprehensive application of phosphogypsum. Therefore, the coupling of the impurity removal link in the acidolysis process of wet-process phosphoric acid has a great effect on the quality improvement of phosphoric acid and phosphogypsum, and the design and establishment of a corresponding system in the process are very important for the overall quality improvement of the product.

The traditional production process is that acidolysis reaction and impurity separation unit phase separate, and whole process flow is longer, and the process is complicated, and impurity exists always and influences holistic reaction sequence in the system, can cause mix with and wrap up the scheduling problem after the reaction finishes simultaneously, has promoted the processing degree of difficulty by a wide margin, therefore whole impurity separation in phosphoric acid and the ardealite is all comparatively difficult with the purification.

CN202011324547.9 provides a method for preparing low-impurity wet-process phosphoric acid and calcium sulfate by controlled acidolysis synchronous extraction of phosphorite, which carries out in-situ extraction on the basis of traditional acidolysis of phosphorite, realizes the rapid and efficient separation of impurities in the phosphorite, omits the rear-end extraction, purification and impurity removal process of crude phosphoric acid in the prior art, simplifies the process flow and reduces the production cost. CN202110068196.8 provides a device system and a method for preparing wet process phosphoric acid by synchronously extracting and separating impurities in acid hydrolysis of phosphorite, provides a relevant system for coupling impurity removal in the acid hydrolysis process of the wet process phosphoric acid, improves the quality of phosphoric acid and calcium sulfate, simplifies the process flow and reduces the treatment difficulty.

However, it can be found from the actual system operation process that although the impurity extraction in the acidolysis reaction process can be realized in the process, in the key three-phase separation process, the existing device and stirring cannot realize the effective separation of the extracting agent, phosphoric acid and phosphogypsum, a part of carbon and silicon particles carried in the phosphogypsum cannot be separated, and meanwhile, the quality of the phosphogypsum is reduced due to incomplete organic phase separation, so that the gypsum utilization is influenced. Therefore, how to carry out three-phase high-efficiency separation and the synergistic decarburization and desilication of the phosphogypsum by a separation device after the reactive extraction is a key problem for realizing the large-scale application of the process.

Disclosure of Invention

The invention aims to provide a device and a method for three-phase separation and synergistic decarburization and desilication of an extracting agent, phosphoric acid and phosphogypsum.

In order to achieve the purpose, the invention adopts the following technical scheme:

in a first aspect, the invention provides a device for three-phase separation and synergistic decarburization and desilication of an extracting agent, phosphoric acid and phosphogypsum, which comprises a settlement separation unit, a back extraction circulation unit and a solid-liquid separation unit.

The sedimentation separation unit comprises a thickener and a double-layer stirring system arranged in the thickener.

The thickener is provided with 1 overflow port for organic phase on the side wall, 1 discharge port for slurry and at least 2 air blowing ports on the bottom, such as 2, 3, 4, 5 or 6, but not limited to the values listed, and other values not listed in the range of values are also applicable.

And the back extraction circulating unit is connected with an organic phase overflow port.

The solid-liquid separation unit is connected with the slurry discharge port.

In the invention, the settling separation unit is used for quickly pre-separating the extracting agent, the phosphoric acid and the phosphogypsum to obtain an organic phase and a solid-liquid mixed phase. Wherein, the organic phase enters the back extraction circulating unit for back extraction treatment to obtain a circulating extractant; and the solid-liquid mixed phase enters the solid-liquid separation unit for solid-liquid separation to obtain the phosphoric acid and the phosphogypsum. The sedimentation separation unit, the back extraction circulation unit and the solid-liquid separation unit are matched with each other, so that the efficient separation of the extracting agent, the phosphoric acid and the phosphogypsum is realized, the quality of the phosphogypsum is improved, and the large-scale popularization and application are facilitated.

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

Preferably, the ratio of the overall height of the thickener to the diameter of the cylindrical side wall is (1-10):1, and may be, for example, 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 recited values, and other values not recited within this range of values are equally applicable.

In the 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.

Preferably, the conical bottom has a cone angle of 120-150 °, such as 120 °, 125 °, 130 °, 135 °, 140 °, 145 ° or 150 °, but is not limited to the recited values, and other values not recited in this range are equally applicable.

Preferably, the material inlet of the thickener is arranged at the junction of phase interfaces inside the thickener.

Preferably, the phase interface junction is located at 1/3-2/3 of the overall height of the thickener, which may be, for example, 1/3, 2/5, 7/15, 8/15, 3/5 or 2/3, but is not limited to the recited values, and other values not recited within this range are equally applicable.

According to the invention, the material inlet of the thickener is arranged at the joint of the phase interface in the thickener, so that the organic phase and the solid-liquid mixed phase can be quickly separated, the mutual entrainment between the two phases is reduced, and the phase separation efficiency is improved.

Preferably, the double-layer stirring system comprises a plug flow type stirring paddle and an anchor type stirring paddle on the same stirring rod.

Preferably, the plug flow type stirring paddle is arranged in the organic phase area of the thickener.

Preferably, the anchor type stirring paddle is arranged in a solid-liquid mixed phase area of the thickener.

According to the invention, different stirring paddle styles are adopted according to the material properties of different phases, and mutual interference does not exist between phases, so that the phase separation efficiency is greatly improved, and the loss of an organic phase band and an organic phase extractant in a solid-liquid mixed phase is reduced.

Preferably, the lower edge of the organic phase overflow port is arranged in the organic phase area of the thickener.

Preferably, the distance between the lower edge of the overflow port of the organic phase and the liquid level of the organic phase is 1/5-1/4, such as 1/5, 21/100, 11/50, 23/100, 6/25 or 1/4, but not limited to the values listed, and other values not listed in this range are also applicable.

Preferably, the distance between the center point of the air blowing opening and the central axis of the thickener is 1/4-3/4, such as 1/4, 1/3, 5/12, 1/2, 7/12, 2/3 or 3/4, of the radius of the cylindrical side wall, but is not limited to the values listed, and other values not listed in the range of values are equally applicable.

Preferably, the angle between the centre line of the air blowing opening and the central axis of the thickener is 10-45 °, for example 10 °, 15 °, 20 °, 25 °, 30 °, 35 °, 40 ° or 45 °, but is not limited to the values listed, and other values not listed in this range are equally applicable.

In the invention, the position and the orientation of the air blowing openings have obvious influence on the decarburization and desilication effect of the gas flotation. When the distance between the center point of the air blowing port and the central axis of the thickener is 1/4-3/4 of the radius of the cylindrical side wall and the included angle between the center line of the air blowing port and the central axis of the thickener is 10-45 degrees, the combination of the two conditions can reduce the content of carbon silicon carried in the phosphogypsum to the maximum extent, thereby greatly improving the quality of the phosphogypsum.

Preferably, the back extraction circulation unit comprises a particle filtering device and an impurity back extraction system which are connected in sequence.

Preferably, the particle filtering device is connected with an organic phase overflow port.

Preferably, the impurity stripping system comprises a stripping column.

Preferably, the solid-liquid separation unit comprises a filtration-washing apparatus.

In a second aspect, the invention provides a method for three-phase separation of an extracting agent, phosphoric acid and phosphogypsum and synergistic decarburization and desilication by using the device in the first aspect, wherein the method comprises the following steps:

(1) pre-separating the three-phase mixed slurry of the extracting agent, the phosphoric acid and the phosphogypsum to obtain an organic phase of the extracting agent and a solid-liquid mixed phase of the phosphoric acid and the phosphogypsum;

(2) carrying out back extraction treatment on the organic phase obtained in the step (1) to obtain a circulating extractant;

(3) carrying out solid-liquid separation on the solid-liquid mixed phase obtained in the step (1) to obtain phosphoric acid and phosphogypsum;

wherein, the steps (2) and (3) are not in sequence.

In the present invention, step (1) is carried out in the sedimentation separation unit described in the first aspect, step (2) is carried out in the stripping circulation unit described in the first aspect, and step (3) is carried out in the solid-liquid separation unit described in the first aspect. The three steps are mutually matched, so that the efficient separation of the extracting agent, the phosphoric acid and the phosphogypsum is realized, the quality of the phosphogypsum is improved, and the large-scale popularization and application are facilitated.

Preferably, the pre-separation in step (1) is accompanied by stirring and air blowing.

According to the invention, the rapid phase separation of the three-phase mixed slurry is realized by stirring, the mutual entrainment between the organic phase and the solid-liquid mixed phase is reduced, and the phase separation efficiency is improved; and the air blowing is to blow air into the solid-liquid mixed phase, and the carbon and silicon in the solid-phase phosphogypsum are synchronized to the liquid phase in a gas flotation mode, so that the content of carbon and silicon carried in the phosphogypsum is reduced, and the quality of the phosphogypsum is improved.

Preferably, the stirring speed is 10-200rpm, for example, 10rpm, 20rpm, 40rpm, 60rpm, 80rpm, 100rpm, 120rpm, 140rpm, 160rpm, 180rpm or 200rpm, but is not limited to the recited values, and other values not recited in the range of the values are also applicable.

Preferably, the blowing rate is 0.1-50L/min, such as 0.1L/min, 1L/min, 10L/min, 20L/min, 30L/min, 40L/min or 50L/min, but is not limited to the recited values, and other values not recited in the range of values are equally applicable.

In the present invention, the air velocity of the air blowing needs to be maintained within a reasonable range. When the gas velocity is less than 0.1L/min, the gas flotation effect is not obvious, and carbon and silicon in the solid-phase phosphogypsum cannot be effectively brought into a liquid phase, so that the quality of the phosphogypsum is reduced; when the gas speed is higher than 50L/min, the gas-liquid mixed phase is brought into the organic phase by the excessively fast gas flow, so that mutual interference exists among phases, the phase separation efficiency is reduced, the loss of the organic phase is increased, and the energy waste is caused.

Preferably, the back extraction treatment in the step (2) is also subjected to solid-liquid separation.

Preferably, the solid-liquid separation in step (3) is further followed by a washing treatment.

Compared with the prior art, the invention has the following beneficial effects:

(1) in the three-phase separation process of the extracting agent, the phosphoric acid and the phosphogypsum, different stirring forms are adopted according to the material properties of different phases, mutual interference does not exist among the phases, only 0.5 hour is needed for continuously treating 1000kg of three-phase mixed slurry, the phase separation efficiency is greatly improved, and the organic phase entrainment and the loss of the organic phase extracting agent in a solid phase are reduced;

(2) in the three-phase separation process, a gas flotation mode is adopted to synchronize carbon and silicon in the solid-phase phosphogypsum into a liquid phase, so that the content of carbon and silicon in the phosphogypsum is reduced, the minimum content of carbon can be reduced to 0.05 wt%, the minimum content of silicon dioxide in the phosphogypsum can be reduced to 1.0 wt%, and the quality of the phosphogypsum is improved.

Drawings

FIG. 1 is a schematic diagram of the device for three-phase separation and synergistic decarburization and desilication of the extracting agent, phosphoric acid and phosphogypsum provided by the invention.

Wherein: 10-a settling separation unit; 11-a thickener; 12-double layer stirring system; 13-organic phase overflow port; 14-slurry outlet; 15-air blowing port; 16-a material inlet; 17-plug flow type stirring paddle; 18-anchor type stirring paddle; 20-a stripping circulation unit; 21-a particulate filter; 22-a stripping column; 30-solid-liquid separation unit.

Detailed Description

The technical solution of the present invention is further explained by the following embodiments. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.

Example 1

The embodiment provides a device for three-phase separation and synergetic decarburization and desilication of an extracting agent, phosphoric acid and phosphogypsum. As shown in fig. 1, the apparatus comprises a settling separation unit 10, a stripping circulation unit 20 and a solid-liquid separation unit 30; the sedimentation separation unit 10 comprises a thickener 11 and a double-layer stirring system 12 arranged inside the thickener 11; the side wall of the thickener 11 is provided with 1 organic phase overflow port 13, and the bottom of the thickener is provided with 1 slurry discharge port 14 and 2 air blowing ports 15; the back extraction circulating unit 20 is connected with an organic phase overflow port 13; the solid-liquid separation unit 30 is connected to the slurry outlet 14.

In this embodiment, the thickener 11 includes a cylindrical side wall and a conical bottom, the ratio of the overall height to the diameter of the cylindrical side wall is 5:1, the taper angle of the conical bottom is 135 °, the material inlet 16 is disposed at the junction of the phase interfaces in the thickener 11, and the junction of the phase interfaces is located at 1/5 of the overall height of the thickener 11. The double-layer stirring system 12 comprises a plug flow type stirring paddle 17 and an anchor type stirring paddle 18 on the same stirring rod, the plug flow type stirring paddle 17 is arranged in an organic phase area of the thickener 11, and the anchor type stirring paddle 18 is arranged in a solid-liquid mixed phase area of the thickener 11. The lower edge of the organic phase overflow port 13 is arranged in the organic phase area of the thickener 11, and the distance between the lower edge and the liquid level of the organic phase is 1/5 of the height of the organic phase area. The distance between the central point of the air blowing port 15 and the central axis of the thickener 11 is 1/2 of the radius of the cylindrical side wall, and the included angle between the central line of the air blowing port 15 and the central axis of the thickener 11 is 30 degrees. The stripping circulation unit 20 comprises a particle filter 21 and a stripping tower 22 which are connected in sequence, and the particle filter 21 is connected with the organic phase overflow port 13. The solid-liquid separation unit 30 is a filtration-washing integrated machine.

Example 2

The embodiment provides a device for three-phase separation and synergetic decarburization and desilication of an extracting agent, phosphoric acid and phosphogypsum. As shown in fig. 1, the apparatus comprises a settling separation unit 10, a stripping circulation unit 20 and a solid-liquid separation unit 30; the sedimentation separation unit 10 comprises a thickener 11 and a double-layer stirring system 12 arranged inside the thickener 11; the side wall of the thickener 11 is provided with 1 organic phase overflow port 13, and the bottom of the thickener is provided with 1 slurry discharge port 14 and 3 air blowing ports 15; the back extraction circulating unit 20 is connected with an organic phase overflow port 13; the solid-liquid separation unit 30 is connected to the slurry outlet 14.

In this embodiment, the thickener 11 includes a cylindrical side wall and a conical bottom, the ratio of the overall height to the diameter of the cylindrical side wall is 1:1, the taper angle of the conical bottom is 120 °, the material inlet 16 is disposed at the junction of the phase interfaces in the thickener 11, and the junction of the phase interfaces is located at 1/3 of the overall height of the thickener 11. The double-layer stirring system 12 comprises a plug flow type stirring paddle 17 and an anchor type stirring paddle 18 on the same stirring rod, the plug flow type stirring paddle 17 is arranged in an organic phase area of the thickener 11, and the anchor type stirring paddle 18 is arranged in a solid-liquid mixed phase area of the thickener 11. The lower edge of the organic phase overflow port 13 is arranged in the organic phase area of the thickener 11, and the distance between the lower edge and the liquid level of the organic phase is 1/4 of the height of the organic phase area. The distance between the central point of the air blowing port 15 and the central axis of the thickener 11 is 1/4 of the radius of the cylindrical side wall, and the included angle between the central line of the air blowing port 15 and the central axis of the thickener 11 is 10 degrees. The stripping circulation unit 20 comprises a particle filter 21 and a stripping tower 22 which are connected in sequence, and the particle filter 21 is connected with the organic phase overflow port 13. The solid-liquid separation unit 30 is a filtration-washing integrated machine.

Example 3

The embodiment provides a device for three-phase separation and synergetic decarburization and desilication of an extracting agent, phosphoric acid and phosphogypsum. As shown in fig. 1, the apparatus comprises a settling separation unit 10, a stripping circulation unit 20 and a solid-liquid separation unit 30; the sedimentation separation unit 10 comprises a thickener 11 and a double-layer stirring system 12 arranged inside the thickener 11; the side wall of the thickener 11 is provided with 1 organic phase overflow port 13, and the bottom of the thickener is provided with 1 slurry discharge port 14 and 4 air blowing ports 15; the back extraction circulating unit 20 is connected with an organic phase overflow port 13; the solid-liquid separation unit 30 is connected to the slurry outlet 14.

In this embodiment, the thickener 11 includes a cylindrical side wall and a conical bottom, the ratio of the overall height to the diameter of the cylindrical side wall is 10:1, the taper angle of the conical bottom is 150 °, the material inlet 16 is disposed at the junction of the phase interfaces in the thickener 11, and the junction of the phase interfaces is located at 2/3 of the overall height of the thickener 11. The double-layer stirring system 12 comprises a plug flow type stirring paddle 17 and an anchor type stirring paddle 18 on the same stirring rod, the plug flow type stirring paddle 17 is arranged in an organic phase area of the thickener 11, and the anchor type stirring paddle 18 is arranged in a solid-liquid mixed phase area of the thickener 11. The lower edge of the organic phase overflow port 13 is arranged in the organic phase area of the thickener 11, and the distance between the lower edge and the liquid level of the organic phase is 1/5 of the height of the organic phase area. The distance between the central point of the air blowing port 15 and the central axis of the thickener 11 is 3/4 of the radius of the cylindrical side wall, and the included angle between the central line of the air blowing port 15 and the central axis of the thickener 11 is 45 degrees. The stripping circulation unit 20 comprises a particle filter 21 and a stripping tower 22 which are connected in sequence, and the particle filter 21 is connected with the organic phase overflow port 13. The solid-liquid separation unit 30 is a filtration-washing integrated machine.

Example 4

The present embodiment provides a device for three-phase separation and synergistic decarburization and desilication of an extracting agent, phosphoric acid and phosphogypsum, wherein the device is the same as that in embodiment 1 except that the distance between the central point of an air blowing port 15 and the central axis of a thickener 11 is changed to 4/5 with the radius of a cylindrical side wall, and thus, the detailed description is omitted here.

Example 5

The embodiment provides a device for three-phase separation and synergistic decarburization and desilication of an extracting agent, phosphoric acid and phosphogypsum, and the device is the same as the device in the embodiment 1 except that an included angle between a central line of an air blowing port 15 and a central axis of a thickener 11 is changed to 60 degrees, so that the detailed description is omitted.

Application example 1

The application example uses the device provided in the embodiment 1 to perform three-phase separation and collaborative decarburization and desilication of the extracting agent, the phosphoric acid and the phosphogypsum, and mainly comprises the following steps:

(1) pre-separating the three-phase mixed slurry of the extracting agent, the phosphoric acid and the phosphogypsum in a settling separation unit 11, and obtaining an organic phase of the extracting agent and a solid-liquid mixed phase of the phosphoric acid and the phosphogypsum along with stirring at a rotating speed of 100rpm and air blowing at an air speed of 25L/min;

(2) sequentially filtering and back-extracting the organic phase obtained in the step (1) in a back-extraction circulating unit 20 to obtain a circulating extractant;

(3) sequentially filtering and washing the solid-liquid mixed phase obtained in the step (1) in a solid-liquid separation unit 30 to obtain phosphoric acid and phosphogypsum;

wherein, the steps (2) and (3) are not in sequence.

In the application example, only 0.6h is needed for continuously treating 800kg of three-phase mixed slurry, the phase separation efficiency is obviously improved, the content of entrained carbon in the solid-phase phosphogypsum is only 0.1 wt%, and the content of silicon dioxide is only 1.8 wt%.

Application example 2

The application example uses the device provided by the embodiment 2 to carry out three-phase separation and collaborative decarburization and desilication of the extracting agent, the phosphoric acid and the phosphogypsum, and mainly comprises the following steps:

(1) pre-separating the three-phase mixed slurry of the extracting agent, the phosphoric acid and the phosphogypsum in a settling separation unit 11, and obtaining an organic phase of the extracting agent and a solid-liquid mixed phase of the phosphoric acid and the phosphogypsum along with stirring at a rotating speed of 10rpm and air blowing at an air speed of 50L/min;

(2) sequentially filtering and back-extracting the organic phase obtained in the step (1) in a back-extraction circulating unit 20 to obtain a circulating extractant;

(3) sequentially filtering and washing the solid-liquid mixed phase obtained in the step (1) in a solid-liquid separation unit 30 to obtain phosphoric acid and phosphogypsum;

wherein, the steps (2) and (3) are not in sequence.

In the application example, only 0.5h is needed for continuously treating 1000kg of three-phase mixed slurry, the phase separation efficiency is obviously improved, the content of entrained carbon in the solid-phase phosphogypsum is only 0.3 wt%, and the content of silicon dioxide is only 2.4 wt%.

Application example 3

The application example uses the device provided by the embodiment 3 to carry out three-phase separation and collaborative decarburization and desilication of the extracting agent, the phosphoric acid and the phosphogypsum, and mainly comprises the following steps:

(1) pre-separating the three-phase mixed slurry of the extracting agent, the phosphoric acid and the phosphogypsum in a settling separation unit 11, and obtaining an organic phase of the extracting agent and a solid-liquid mixed phase of the phosphoric acid and the phosphogypsum along with stirring at the rotating speed of 200rpm and air blowing at the air speed of 0.1L/min;

(2) sequentially filtering and back-extracting the organic phase obtained in the step (1) in a back-extraction circulating unit 20 to obtain a circulating extractant;

(3) sequentially filtering and washing the solid-liquid mixed phase obtained in the step (1) in a solid-liquid separation unit 30 to obtain phosphoric acid and phosphogypsum;

wherein, the steps (2) and (3) are not in sequence.

In the application example, only 1 hour is needed for continuously treating 500kg of three-phase mixed slurry, the phase separation efficiency is obviously improved, the content of entrained carbon in the solid-phase phosphogypsum is only 0.05 wt%, and the content of silicon dioxide is only 1.0 wt%.

Application example 4

In the application example, the device provided in example 4 is used to perform three-phase separation of the extractant, the phosphoric acid and the phosphogypsum and synergistic decarburization and desilication, and the specific steps and conditions are the same as those in application example 1, so that the detailed description is omitted here.

In the application example, only 0.6h is needed for continuously treating 800kg of three-phase mixed slurry, the phase separation efficiency is obviously improved, however, the content of entrained carbon in the solid-phase phosphogypsum is 0.7 wt%, the content of silicon dioxide is 4.3 wt%, and the quality of the phosphogypsum is not as good as that of the application example 1.

Application example 5

The device provided in example 5 is applied to three-phase separation of the extractant, the phosphoric acid and the phosphogypsum and synergistic decarburization and desilication, and the specific steps and conditions are the same as those in example 1, so that the detailed description is omitted here.

In the application example, only 1 hour is needed for continuously treating 500kg of three-phase mixed slurry, the phase separation efficiency is obviously improved, but the content of entrained carbon in the solid-phase phosphogypsum is 0.2 wt%, the content of silicon dioxide is 2.3 wt%, and the quality of the phosphogypsum is not as good as that of the application example 1.

Application example 6

In the application example, the device provided in example 1 is applied to three-phase separation of the extractant, the phosphoric acid and the phosphogypsum and synergistic decarburization and desilication, and the specific steps are the same as those in example 1 except that the gas velocity of the blowing gas is reduced to 0.08L/min, so that the details are not repeated herein.

In the application example, only 0.5h is needed for continuously treating 1000kg of three-phase mixed slurry, the phase separation efficiency is obviously improved, but the content of entrained carbon in the solid-phase phosphogypsum is 0.7 wt%, the content of silicon dioxide is 5.6 wt%, and the quality of the phosphogypsum is not as good as that of the application example 1.

Application example 7

In the application example, the device provided in example 1 is applied to three-phase separation of the extractant, the phosphoric acid and the phosphogypsum and synergistic decarburization and desilication, and the specific steps are the same as those in example 1 except that the gas velocity of the blowing gas is increased to 55L/min, so that the details are not repeated herein.

In the application example, 1.2 hours are needed for continuously treating 800kg of three-phase mixed slurry, the phase separation efficiency is not as good as that of the application example 1, however, the content of entrained carbon in the solid-phase phosphogypsum is only 0.08 wt%, the content of silicon dioxide is only 1.5 wt%, and the quality of the phosphogypsum is obviously improved.

Therefore, in the three-phase separation process of the extracting agent, the phosphoric acid and the phosphogypsum, different stirring forms are adopted according to the material properties of different phases, mutual interference does not exist between the phases, only 0.5 hour is needed for continuously treating 1000kg of three-phase mixed slurry, the phase separation efficiency is greatly improved, and the organic phase entrainment and the loss of the organic phase extracting agent in a solid phase are reduced; in addition, in the three-phase separation process, the carbon and silicon in the solid-phase phosphogypsum are synchronized to the liquid phase in a gas flotation mode, so that the content of carbon and silicon in the phosphogypsum is reduced, the carbon content can be reduced to 0.05 wt% at least, the content of silicon dioxide in the phosphogypsum is reduced to 1.0 wt% at least, and the quality of the phosphogypsum is improved.

The applicant declares that the above description is only a specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and it should be understood by those skilled in the art that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are within the scope and disclosure of the present invention.