A defluorination device and method for wet-process phosphoric acid dilute acid

Abstract

The present application relates to the field of wet-process phosphoric acid defluorination, and specifically discloses a defluorination device and method for wet-process phosphoric acid dilute acid, which includes: a reactor for adding phosphate slurry and sulfuric acid to generate a reaction liquid and fluorine gas; a reaction tower; a defluorination filler arranged at the top of the reaction tower; a fluorine gas conveying member and a reaction liquid conveying member; the fluorine gas conveying member forms a plurality of air intake areas for outputting axial flow wind at the bottom of the reaction tower; the plurality of air intake areas are distributed in a circular array around a fixed axis so that the fluorine gas conveying member forms a spiral wind along the length direction of the fixed axis; the reaction liquid conveying member forms a plurality of discharge ports along the extension direction of the fixed axis for discharging the reaction liquid in the form of mist into the spiral wind. The present application has the effect of increasing the speed of defluorination or defluorination, and improving the recovery rate of fluorine gas.

Description

Technical Field

[0001] The present application relates to the field of wet-process phosphoric acid defluorination, and in particular to a device and method for defluorination of dilute wet-process phosphoric acid. Background Art

[0002] Wet-process phosphoric acid defluorination primarily involves treating phosphate rock slurry with sulfuric acid in a reactor. The reaction liquid in the reactor is then sprayed onto the tail gas in the reactor. Fluorine is absorbed in a spray tower to achieve defluorination. After the reaction is complete, defluorinated phosphoric acid is obtained from the reactor and the fluorine gas is recycled as defluorinated phosphoric acid. The tail gas is primarily fluorine gas.

[0003] When spraying the tail gas with the reaction liquid, the reaction liquid and fluorine gas are mainly used to pass through the defluorination packing, and in a countercurrent manner to ensure full contact between the two, so as to fully recover the fluorine gas. The reaction liquid will form a liquid film in the pores of the defluorination packing. The liquid film is the liquid accumulated in the pores. As the reaction liquid continuously flows into and out of the pores, the reaction liquid will fill the pores. Then, the fluorine gas will penetrate the pores and blow the reaction liquid away, which can increase the degree of contact between the fluorine gas and the reaction liquid.

[0004] However, the applicant believes that there are the following disadvantages: when the fluorine gas blows away the liquid film formed by the reaction liquid, it is difficult for the reaction liquid to completely fill the pores again, so the reaction liquid will only partially flow through the edges of the pores, resulting in uneven contact between the fluorine gas and the reaction liquid when they pass through the defluorination filler, ultimately leading to a slow defluorination or fluorine reduction rate and a low fluorine gas recovery rate. Summary of the Invention

[0005] In order to improve the problems of slow defluorination or fluorine reduction and low fluorine gas recovery rate, the present application provides a wet-process phosphoric acid dilute acid fluorine reduction device.

[0006] The present application provides a defluorination device for wet-process dilute phosphoric acid, which adopts the following technical solution: a defluorination device for wet-process dilute phosphoric acid, comprising: a reactor for adding phosphate slurry and sulfuric acid to generate reaction liquid and fluorine gas; a reaction tower for receiving the reaction liquid and fluorine gas through a conveying component, and adding both the fluorine gas and the reaction liquid to the reaction tower; a defluorination filler, arranged at the upper part of the reaction tower; wherein the conveying component comprises: a fluorine gas conveying member and a reaction liquid conveying member; the fluorine gas conveying member forms a plurality of air inlet areas for outputting axial flow wind at the bottom of the reaction tower; the plurality of air inlet areas are distributed in a circular array around a fixed axis, so that the fluorine gas conveying member forms a spiral wind along the length direction of the fixed axis; the reaction liquid conveying member forms a plurality of exhaust ports along the extension direction of the fixed axis for discharging the reaction liquid in the form of mist into the spiral wind; some of the exhaust ports are located above the defluorination filler.

[0007] By adopting the above technical solution, fluorine gas is made to flow upward in a spiral manner in the reaction tower, then an empty area will be formed in the middle of the fluorine gas, and the objects in this empty area will be sucked into the spiral wind under the action of air pressure. What is provided in this empty area is a reaction liquid conveying part, so that the reaction liquid is discharged outward, so that the reaction liquid can flow quickly into the spiral wind, and the spiral wind slows down the speed of fluorine gas flowing in the reaction tower, thereby increasing the time for the reaction liquid to contact with fluorine gas, making the reaction liquid absorb fluorine gas more time, and the degree of both reactions is more thorough. The arrangement of the partial outlet above the defluorination filler is to form a liquid film of the reaction liquid in the defluorination filler, and the liquid film needs to be broken when fluorine gas passes through the defluorination filler. The moment the liquid film is broken, multiple droplets will be splashed, so that the reaction liquid is mixed into multiple corners in the fluorine gas, and fluorine gas is better reacted with the reaction liquid. In addition, the present application discharges the reaction liquid into the spiral wind because the outlet can prevent fluorine gas from contacting the outlet, thereby avoiding the outlet from being corroded by fluorine gas, and can ensure the use effect and improve the service life for a long time. Part of the reaction liquid is mixed with fluorine gas below the defluorination filler, and then part of the fluorine gas reacts with part of the reaction liquid, while the other part is mixed together without reacting, so that what breaks through the liquid membrane is the mixture of reaction liquid and fluorine gas. After breaking through the liquid membrane, part of the reaction liquid will remain, and the liquid membrane will be quickly blocked, thereby avoiding the fluorine gas directly breaking through the liquid membrane and forming a pore. When the pore is not filled and blocked, the reaction liquid in the fluorine gas can fill part of the pore when passing through the pore, helping to quickly recover, thereby increasing the degree of contact and reaction between the fluorine gas and the reaction liquid when the fluorine gas breaks through the liquid membrane.

[0008] Optionally, the reaction liquid conveying component includes: a fixed tube and a connecting tube; the connecting tube is used to connect the fixed tube with the reactor so that the reaction liquid in the reactor is added to the fixed tube; the fixed tube is used to form an infusion cavity and the discharge port connected to the infusion cavity; the discharge port is located on the side wall of the fixed tube; a driving component is provided on the fixed tube, and the driving component is used to add the reaction liquid into the fixed tube and discharge the reaction liquid outward at the discharge port.

[0009] By adopting the above technical solution, a fixed rod is used to guide the reaction liquid, and the discharge port is opened on the side wall of the fixed tube, so that the reaction liquid can be discharged in a direction perpendicular to the fixed axis, thereby facilitating rapid addition to the spiral wind.

[0010] Optionally, the fixed tube portion is located outside the reaction tower; the driving member includes: a spiral conveying piece and a power structure for driving the spiral conveying piece to rotate; the spiral conveying piece is located at the lower part of the fixed tube; the spiral conveying piece abuts against the inner wall surface of the fixed tube.

[0011] By adopting the above technical solution, the driving member adopts a spiral conveying piece arranged in a fixed tube. Then, after a long period of use, the spiral conveying piece will be in contact with the reaction liquid for a long time. Even if it is corroded, the normal use of the spiral conveying piece can still be guaranteed. On the contrary, if a pump body is used, the seals, bearings and other components of the pump body will be easily corroded after a long period of use, leading to problems such as leakage and wear. In addition, acidic liquids may also accelerate scaling and clogging inside the pump body, reducing the efficiency of the water pump. The design using a spiral conveying piece can avoid the appearance of components such as seals and bearings, and scaling and clogging on the spiral conveying piece will not affect its normal use due to the large pores in the spiral cavity of the spiral conveying piece.

[0012] Optionally, the spiral conveying piece is arranged at the lower part of the fixed tube, and a pressure control structure is arranged at the upper part of the fixed tube, and the pressure control structure is used to increase and decrease the pressure of the infusion cavity in the fixed tube.

[0013] By adopting the above technical solution, the lower part of the fixed tube is a spiral conveyor. As the spiral conveyor rotates continuously, the reaction liquid is gradually transported upward from the bottom of the fixed tube until the height of the reaction liquid exceeds the spiral. However, due to the continuous rotation of the spiral, the reaction liquid is continuously added to the fixed tube, regardless of the height of the spiral. After the height of the reaction liquid in the fixed tube reaches a certain level, the pressure control structure applies pressure to the upper part of the fixed tube, which causes the reaction liquid in the fixed tube to be squeezed outward. At this time, the conveying force provided by the spiral conveyor and the pressure provided by the pressure control structure increase the force of the reaction liquid in the fixed tube to be discharged outward from the discharge port. Therefore, when the rotation speed of the spiral conveyor reaches the maximum, the pressure control structure can also increase the speed of drainage at the discharge port.

[0014] Optionally, a plurality of inclined slots are provided on the defluorination filler; the extension direction of the inclined slots matches the spiral direction of the spiral wind, so that when the spiral wind enters the inclined slots, the flow direction of the spiral wind is the same as the guide direction of the inclined slots; a liquid receiving area is formed above the defluorination filler; the liquid receiving area is used to receive the reaction liquid and fill the reaction liquid into the inclined slots.

[0015] By adopting the above technical solution, the setting of the chute can increase the time for the mixture of fluorine gas and reaction liquid to pass through the defluorination filler, and the direction in which the spiral wind enters the chute is the same as the flow direction of the spiral wind. Therefore, the spiral wind will not encounter resistance when passing through the chute, and the fluorine gas can better pass through the chute, thereby further increasing the degree of complete contact between the fluorine gas and the reaction liquid and increasing the degree of fluorine reduction and defluorination.

[0016] Optionally, the projection of the chute on the end surface of the defluorination filler is constructed to have an arc-shaped edge line and a straight edge line; the arc-shaped edge line and the straight edge line are connected.

[0017] By adopting the above technical solution, the inclined groove is in an arc shape, which further increases the contact time between the fluorine gas and the defluorination filler, and also increases the contact time between the fluorine gas and the reaction liquid.

[0018] Optionally, an inlet and an outlet are formed on the defluorination filler; both the inlet and the outlet are connected to the edges of the chute; an injection port is also formed on the defluorination filler; the injection port is connected to the middle of the chute.

[0019] By adopting the above technical solution, the injection port is connected to the middle of the chute, so the reaction liquid can penetrate into the middle of the chute through the injection port, thereby forming a liquid film in the middle of the chute. Since the reaction liquid discharged from the discharge port is below the defluorination filler, the reaction liquid enters the chute together with the spiral wind, thereby forming a liquid film at the outlet of the chute. There is also a discharge port above the defluorination filler, and the reaction liquid discharged from the discharge port falls directly on the defluorination filler, thereby forming a liquid film on the inlet, thereby forming a multi-layer liquid film in the chute, which greatly improves the contact time between fluorine gas and reaction liquid, and the effect of the defluorination filler on the defluorination and defluorination process.

[0020] Optionally, along the fixed axis direction, the inclined groove has multiple circles in the defluorination filler; the injection port passes through the multiple circles of the inclined groove, so that multiple layers of reaction liquid films in contact with fluorine gas are formed in the inclined groove.

[0021] By adopting the above technical solution, when the injection port is connected to the chute, there will be multiple connecting positions between the injection port and the chute, thereby forming more liquid films in the chute, and further increasing the time for the fluorine gas to pass through the chute, thereby improving the degree of defluorination and fluorine reduction of the fluorine gas.

[0022] Optionally, the spiral wind has a spiral wind forming area and a spiral wind shaping area in the reaction tower; a temperature control component is provided in the reaction tower, and the temperature control component is used to form a heating area in the spiral wind shaping area to increase the temperature of the fluorine gas.

[0023] By adopting the above technical solution, the spiral wind is heated after it is formed. When the fluorine gas has not formed a spiral wind, the fluorine gas will contact the fixed tube. At this time, the fluorine gas is not heated in order to avoid the problem of increased corrosiveness caused by the temperature increase of the fluorine gas, thereby avoiding the problem of corrosion of the discharge port of the fixed tube due to the excessive corrosiveness of the fluorine gas when the fluorine gas contacts the discharge port of the fixed tube.

[0024] The present application also provides a method for defluorination of wet-process phosphoric acid dilute acid, comprising adding phosphate slurry and sulfuric acid into a reactor; forming a plurality of air inlet areas for outputting axial flow wind through a fluorine gas conveying member, so that the fluorine gas conveying member forms a spiral wind along the length direction of a fixed axis; forming a plurality of discharge ports along the extension direction of the fixed axis through a reaction liquid conveying member, so that the reaction liquid is discharged into the spiral wind in the form of mist; the spiral wind carries the mist reaction liquid upward and flows toward the defluorination filler in the reaction tower; the discharge port also discharges the reaction liquid above the defluorination filler, so that the reaction liquid on the defluorination filler flows downward.

[0025] In summary, this application includes at least one of the following beneficial technical effects:

[0026] 1. While the fluorine gas is being treated by the defluorination filler, the fluorine gas is collected below the defluorination filler in the form of a spiral wind. The spiral wind is mainly concentrated at the edge of the reaction tower. Then, the reaction liquid is discharged into the spiral wind in the form of mist through multiple discharge ports formed along the fixed axis. The spiral wind carries the mist reaction liquid through the defluorination filler, allowing the fluorine gas to contact the reaction liquid for a long time, thereby increasing the speed of fluorine gas treatment and the efficiency of fluorine gas recovery.

[0027] 2. Fluorine gas carrying the mist reaction liquid passes through the defluorination filler, causing the mist reaction liquid to come into contact with the reaction liquid in the pores of the defluorination filler, thereby blowing away the liquid film formed in the defluorination filler. The mist reaction liquid can then cooperate with the reaction liquid on the defluorination filler to re-form a liquid film.

[0028] 3. By discharging the reaction liquid from the center to the surrounding areas, the fluorine gas in the spiral wind will not come into contact with the discharge port, thereby ensuring that the discharge port will not be corroded and increasing its service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is an overall schematic diagram according to an embodiment of the present application;

[0030] Figure 2 This is a structural diagram of a part of the embodiment, mainly showing the Figure 1 structure;

[0031] Figure 3 It is a schematic structural diagram of a part of the embodiment, mainly showing the internal structure of the reaction tower;

[0032] Figure 4 This is a structural diagram of a part of the embodiment, mainly showing the Figure 2 structure;

[0033] Figure 5 It is a structural schematic diagram of a part of the embodiment, mainly showing the structure inside the fixed tube, and is presented in an exploded view;

[0034] Figure 6 This is a schematic structural diagram of a portion of the embodiment, mainly showing the structure of the solution of Example 8;

[0035] Figure 7 It is a schematic structural diagram of a part of the embodiment, mainly showing the internal structure of the reaction tower of Example 8;

[0036] Figure 8 This is a schematic structural diagram of a portion of the embodiment, mainly showing the internal structure of the fixed tube of embodiment 8;

[0037] Figure 9 yes Figure 8 A magnified view of part A;

[0038] Figure 10 It is a schematic structural diagram of a part of the embodiment, mainly showing the structure of the defluorinated filler;

[0039] Figure 11 This is a schematic structural diagram of a portion of an embodiment, mainly showing the structure of a fixed tube, a heat dissipation plate, and some surrounding parts;

[0040] Figure 12 This is a schematic structural diagram of a part of the embodiment, mainly showing Figure 1 Cross-sectional structure;

[0041] Figure 13 This is a structural diagram of a part of the embodiment, mainly showing the Figure 12 structure;

[0042] Figure 14 yes Figure 13 A magnified view of part B;

[0043] Figure 15 This is a schematic structural diagram of a part of the embodiment, mainly showing Figure 6 Cross-sectional structure;

[0044] Figure 16 yes Figure 15 Magnified view of part C;

[0045] Figure 17 It is a structural schematic diagram of a part of the embodiment, mainly showing the structure when the defluorination filler is located above all the discharge ports.

[0046] Figure numerals: 1. reactor; 2. reaction tower; 3. defluorination filler; 31. inclined chute; 32. arc edge; 33. straight edge; 34. injection port; 4. treatment tower; 5. fluorine gas conveying member; 51. air inlet area; 52. fluorine gas conveying pipe; 53. fluorine gas pump body; 54. fluorine gas axial flow fan; 6. reaction liquid conveying member; 61. fixed pipe; 611. discharge port; 612. sealing plate; 613. spiral wind forming area; 614. spiral wind forming area; 62. connecting pipe; 63. driving member; 631. spiral conveying sheet; 632. power structure; 64. support area; 7. fixed axis; 8. pressure control structure; 81. piston block; 82. heat sink; 83. water supply pipe; 84. water pump; 85. water tank; 86. spare pump body; 87. spare pipe; 88. spiral blade; 9. reaction liquid injection pipe. DETAILED DESCRIPTION

[0047] The following is combined with Figure 1-17 This application is described in further detail. Example 1

[0048] A defluorination device for wet-process phosphoric acid dilute acid comprises: a reactor 1, a reaction tower 2, a defluorination filler 3 and a treatment tower 4; wherein the reaction tower 2 adopts a large or small spray tower according to the size of the reactor 1, and the treatment tower 4 adopts a fluorine gas absorption treatment tank, which is mainly used to absorb and treat the fluorine gas that overflows.

[0049] Specifically, reactor 1 is used to add phosphate slurry and sulfuric acid, stirring the phosphate slurry and sulfuric acid to generate a reaction liquid and fluorine gas. The reaction liquid collects at the bottom of reactor 1, and the fluorine gas collects at the top of reactor 1. Reaction tower 2 is used to receive the reaction liquid and fluorine gas through a conveying assembly and add both the fluorine gas and reaction liquid to reaction tower 2. Defluorination packing 3 is disposed at the top of reaction tower 2.

[0050] The conveying assembly includes a fluorine gas conveying member 5 and a reaction liquid conveying member 6. The fluorine gas conveying member 5 forms multiple air intake areas 51 at the bottom of the reaction tower 2 for outputting axial airflow. The multiple air intake areas 51 are arranged in a circular array around a fixed axis 7, so that the fluorine gas conveying member 5 forms a spiral airflow along the length of the fixed axis 7. The fluorine gas conveying member 5 includes a fluorine gas conveying pipe 52, a fluorine gas pump body 53, and a fluorine gas axial flow fan 54. The fluorine gas conveying pipe 52 is used to connect the top of the reactor 1 with the lower part of the reaction tower 2. The fluorine gas pump body 53 is used to pump air to ensure that the fluorine gas is discharged into the reaction tower 2 with sufficient force. The fluorine gas axial flow fan 54 is located at the outlet of the fluorine gas conveying pipe 52. The fluorine gas conveying pipe 52 has multiple outlets, namely, the outlet of the fluorine gas conveying pipe 52 is the air intake area 51, and the air intake area 51 is where the fluorine gas is added to the reaction tower 2. The multiple outlets of the fluorine gas delivery pipe 52 are achieved by dividing the fluorine gas delivery pipe 52 into a main pipeline and multiple branch pipelines, each branch pipeline representing an outlet of the fluorine gas delivery pipe 52. Each branch pipeline is connected to the reaction tower 2. The fluorine gas axial flow fan 54 is provided at the end of the branch pipeline. Preferably, the fluorine gas axial flow fan 54 is located inside the reaction tower 2. The multiple axial flow fans discharge the fluorine gas outward and blow it in opposite directions, thereby forming a spiral wind in the reaction tower 2 after the multiple fluorine gases are blown in opposite directions. The spiral wind is mainly distributed in the edge area of ​​the reaction tower 2 and forms an empty area in the middle of the reaction tower 2. This empty area is where the fixed axis 7 is located.

[0051] The reaction liquid conveying member 6 forms a plurality of discharge ports 611 along the extension direction of the fixed axis 7 for discharging the reaction liquid in the form of mist into the spiral wind. Some of the discharge ports 611 are located above the defluorination filler 3. The reaction liquid conveying member 6 is composed of a fixed pipe 61 and a reaction liquid pump body. The reaction liquid pump body connects the reactor 1 with the fixed pipe 61 through a hose, and the reaction liquid pump body adds the reaction liquid in the reactor 1 to the fixed pipe 61. The fixed pipe 61 is used to form the discharge port 611. The discharge port 611 is a hole on the side wall of the fixed pipe 61 or a nozzle provided at the end of the fixed pipe 61. The nozzle is used to discharge the reaction liquid outward in a direction different from the extension direction of the fixed axis 7. Preferably, the discharge port 611 discharges the reaction liquid outward in a direction perpendicular to the extension direction of the fixed axis 7. The fixed axis 7 matches the axis of the fixed pipe 61, and the fixed axis 7 also matches the center line of the reaction tower 2.

[0052] By adopting the above technical solution, the fluorine gas flows upward in a spiral manner in the reaction tower 2, forming an empty area in the middle of the fluorine gas. Objects in this empty area are sucked into the spiral wind under the action of air pressure. The reaction liquid conveying member 6 is provided in this empty area to discharge the reaction liquid outward, so that the reaction liquid can flow quickly into the spiral wind. The spiral wind slows the flow of fluorine gas in the reaction tower 2, thereby increasing the contact time between the reaction liquid and the fluorine gas, allowing the reaction liquid to absorb the fluorine gas more time and the degree of reaction between the two to be more thorough. The partial discharge port 611 is arranged above the defluorination packing 3 to form a liquid film of the reaction liquid in the defluorination packing 3. When the fluorine gas penetrates the defluorination packing, it needs to break through the liquid film. The moment the liquid film is broken, multiple droplets will splash, thereby mixing the reaction liquid into multiple corners of the fluorine gas, better allowing the fluorine gas and the reaction liquid to react. In addition, the present application discharges the reaction liquid into the spiral wind because the outlet 611 can prevent the fluorine gas from contacting the outlet 611, thereby preventing the outlet 611 from being corroded by the fluorine gas, and can ensure the use effect and improve the service life for a long time. Below the defluorination filler 3, part of the reaction liquid is mixed with the fluorine gas, and then part of the fluorine gas reacts with part of the reaction liquid, and the other part is mixed together without reacting, so that the mixture of the reaction liquid and the fluorine gas will be broken through the liquid film. After breaking through the liquid film, the reaction liquid will have a residual part, and the liquid film will be quickly blocked, thereby avoiding the fluorine gas from directly breaking through the liquid film and forming a pore. When the pore is not filled and blocked, the reaction liquid in the fluorine gas can fill part of the pore when passing through the pore, helping to recover quickly, thereby improving the degree of contact reaction between the fluorine gas and the reaction liquid when the fluorine gas breaks through the liquid film.

[0053] In addition, the treatment tower 4 is connected to the top of the reaction tower 2, and the unreacted fluorine gas is discharged into the treatment tower 4 for treatment to prevent air pollution. Example 2

[0054] The difference between the reaction liquid transport member 6 and Example 1 is that the reaction liquid transport member 6 includes a fixed tube 61, a connecting tube 62, and a driving member 63. The connecting tube 62 is used to connect the fixed tube 61 with the reactor 1 so that the reaction liquid in the reactor 1 is added to the fixed tube 61. The fixed tube 61 is used to form an infusion channel and the discharge port 611 connected to the infusion channel. The infusion channel is the hollow part in the middle of the fixed tube 61. The discharge port 611 is located on the side wall of the fixed tube 61, and the opening direction of the discharge port 611 is perpendicular to the fixed axis 7. The driving member 63 is used to add the reaction liquid to the fixed tube 61 and discharge the reaction liquid outward at the discharge port 611.

[0055] The specific solution of the driving member 63 is as follows: the driving member 63 includes a spiral conveying piece 631 and a power structure 632 for driving the spiral conveying piece 631 to rotate. The spiral conveying piece 631 is located at the lower part of the fixed tube 61. The spiral conveying piece 631 abuts against the inner wall surface of the fixed tube 61. The spiral conveying piece 631 rotates in the fixed tube 61. After the reaction liquid is added to the spiral conveying piece 631, the spiral conveying piece 631 contacts the reaction liquid. In addition, the spiral conveying piece 631 rotates, which will convey the reaction liquid. In addition, the spiral conveying piece 631 abuts against the inner wall of the fixed tube 61. Therefore, in the process of conveying the reaction liquid, the reaction liquid can no longer overflow outward from the edge of the spiral conveying piece 631. The spiral conveying piece 631 is used to realize the conveyance of the reaction liquid in the fixed tube 61. According to the rotation direction of the spiral conveying piece 631, the reaction liquid can be conveyed from bottom to top or from top to bottom. It is preferred to add the reaction liquid to the bottom of the fixed tube 61 and then convey the reaction liquid from bottom to top.

[0056] The advantage of using spiral conveyor sheet 631 is that even if it corrodes over time due to prolonged contact with the reaction solution, it can still function properly. In contrast, using a pump body can lead to corrosion of components such as seals and bearings over time, causing leakage, wear, and other problems. Furthermore, acidic liquids can accelerate scaling and clogging within the pump body, reducing the efficiency of water pump 84. The design of spiral conveyor sheet 631 avoids scaling and clogging of components such as seals and bearings, and due to the large pores in the spiral cavity of spiral conveyor sheet 631, scaling and clogging on spiral conveyor sheet 631 are not affected.

[0057] More specifically, the fixed tube 61 is partially located outside the reaction tower 2, and preferably, the fixed tube 61 is partially located outside below the reaction tower 2. A support tower is provided below the reaction tower 2, so that the fixed tube 61 is partially located in the support tower, thereby realizing that the fixed tube 61 is partially located outside the support tower, and the support tower can be formed below the reaction tower 2 by providing a sealing plate 612 in the reaction tower 2. The purpose is to install a power structure 632 below the reaction tower 2. The power structure 632 includes a drive motor and a drive shaft transmission component. The drive shaft is fixed to the spiral conveying piece 631. The drive motor is connected to the drive shaft through the transmission component, so that the drive motor drives the spiral conveying piece 631 to rotate through the transmission component and the drive shaft.

[0058] Among them, the transmission component adopts one of gear transmission, belt transmission and chain transmission. Example 3

[0059] The difference between the reaction liquid conveying member 6 and the embodiment 2 is that the spiral conveying piece 631 is arranged at the lower part of the fixed tube 61. The upper part of the fixed tube 61 is provided with a pressure control structure 8, which is used to increase and decrease the pressure of the infusion channel in the fixed tube 61.

[0060] The pressure control structure 8 includes: a piston block 81, a counterweight, a rope and a winch. The winch is connected to the piston block 81 through a rope, and the counterweight is set on the piston block 81. The winch is set on the ground, the piston block 81 is set on the upper part of the fixed tube 61, the piston block 81 abuts against the inner wall of the fixed tube 61, and the rope is connected to the piston block 81 by being wound around the guide wheel. The winch drives the piston block 81 upward through the rope, or the winch loosens part of the rope and the weight of the counterweight to move the piston block 81 downward. In this way, it is convenient to repair the winch in the event of a fault, and the reaction tower 2 also has a certain height, so compared with some other control methods, it can avoid high-altitude maintenance.

[0061] Because the lower portion of the fixed tube 61 is provided with a spiral conveying piece 631, as the spiral conveying piece 631 rotates continuously, the reaction liquid is gradually transported upward from the bottom of the fixed tube 61 until the height of the reaction liquid exceeds the spiral piece. However, due to the continuous rotation of the spiral piece, the reaction liquid is continuously added to the fixed tube 61, regardless of the height of the spiral piece. After the height of the reaction liquid in the fixed tube 61 reaches a certain level, the piston block 81 moves downward to apply pressure to the reaction liquid in the fixed tube 61, thereby forcing the reaction liquid in the fixed tube 61 outward. At this time, the conveying force provided by the spiral conveying piece 631 and the pressure provided by the pressure control structure 8 increase the force with which the reaction liquid in the fixed tube 61 is discharged outward from the discharge port 611. Therefore, when the rotation speed of the spiral conveying piece 631 reaches the maximum, the pressure control structure 8 can also increase the speed of drainage from the discharge port 611. Example 4

[0062] The defluorinating filler 3 differs from Example 1 in that: Multiple chute slots 31 are formed on the defluorinating filler 3; the extension direction of the chute slots 31 matches the spiral direction of the spiral wind, so that when the spiral wind enters the chute slots 31, the flow direction of the spiral wind is the same as the flow direction of the chute slots 31. A liquid receiving area is formed above the defluorinating filler 3; the liquid receiving area is used to receive the reaction liquid and allow the reaction liquid to be filled into the chute slots 31. The projection of the chute slots 31 on the end surface of the defluorinating filler 3 is constructed with an arcuate edge 32 and a straight edge 33; the arcuate edge 32 and the straight edge 33 are connected. Therefore, the inclined grooves 31 are distributed along an arc in the defluorination filler 3, so that the inclined grooves 31 can match the flow direction of the spiral wind throughout the entire process, reducing the resistance of the fluorine gas passing through the inclined grooves 31, and achieving the same effect as when the fluorine gas passes through the holes on the traditional defluorination filler 3. However, the use of the inclined grooves 31 and the distribution of the inclined grooves 31 along the arc prolongs the time for the fluorine gas to pass through the defluorination filler 3, thereby increasing the effect of the liquid film formed by the fluorine gas and the reaction liquid on the defluorination filler 3.

[0063] In other embodiments, the defluorinating filler 3 further comprises an inlet and an outlet, both of which communicate with the edges of the chute 31. The defluorinating filler 3 further comprises an injection port 34, which communicates with the center of the chute 31. The injection port 34 is perpendicular to the end of the defluorinating filler 3. The chute 31 has multiple turns along the fixed axis 7 within the defluorinating filler 3. The injection port 34 penetrates multiple turns of the chute 31, thereby forming multiple layers of reaction liquid films in contact with the fluorine gas within the chute 31.

[0064] The injection port 34 is connected to the middle of the chute 31, so the reaction liquid can penetrate into the middle of the chute 31 through the injection port 34, thereby forming a liquid film in the middle of the chute 31. Since the reaction liquid is discharged from the outlet 611 below the defluorination filler 3, the reaction liquid enters the chute 31 along with the spiral wind, thereby forming a liquid film at the outlet of the chute 31. There is also a outlet 611 above the defluorination filler 3. The reaction liquid discharged from the outlet 611 falls directly on the defluorination filler 3, thereby forming a liquid film at the inlet, thereby forming a multi-layer liquid film in the chute 31. The injection port 34 will have multiple communication locations with the chute 31, thereby forming more liquid films in the chute 31, and more to increase the time for the fluorine gas to pass through the chute 31, thereby improving the degree of defluorination and fluorine reduction of the fluorine gas. Example 5

[0065] The difference from Example 1 is that the spiral wind has a spiral wind forming area 613 and a spiral wind forming area 614 in the reaction tower 2. The spiral wind forming area 613 refers to a space where the fluorine gas in multiple branch pipes is blown outward and blown together through the fluorine gas axial flow fan 54 to form a spiral wind. The spiral wind forming area 614 refers to an area where the spiral wind has been formed. A temperature control component is provided in the reaction tower 2, and the temperature control component is used to form a heating area in the spiral wind forming area 614 to heat the fluorine gas. In this example, the temperature control component adopts a method of winding multiple circles of heating tubes around the outside of the reaction tower 2, and can also wind multiple circles of heating tubes around the inside of the reaction tower 2, thereby heating the spiral wind forming area 614. The spiral wind is heated after it is formed. When the fluorine gas has not formed a spiral wind, the fluorine gas will contact the fixed tube 61. The fluorine gas is not heated at this time to avoid the problem of increased corrosiveness caused by the increase in temperature of the fluorine gas, thereby avoiding the problem of fluorine gas corroding the exhaust port 611 on the fixed tube 61 due to its excessive corrosiveness when the fluorine gas contacts the exhaust port 611 on the fixed tube 61. Example 6

[0066] The difference from Example 5 is that the temperature control component is a heat sink 82 arranged on the outer wall of the fixed tube 61. The pressure control structure 8 in this example includes: a water supply pipe 83, a water pump 84, a water tank 85 and a heating element. The heating element is used to heat the water, and the heating element adopts the existing technology. The water pump 84 is connected to the water tank 85, and the heating element is used to heat the water in the water tank 85. The water supply pipe 83 is used to connect the water pump 84 with the upper part of the fixed tube 61, so that the water pump 84 can add the water in the water tank 85 to the fixed tube 61. The water temperature in the water tank 85 is high, so after entering the fixed tube 61, it will heat the fixed tube 61. The fixed tube 61 allows the heat of the water to be quickly dissipated outward through the heat sink 82, thereby achieving the temperature increase of the spiral wind forming area 614.

[0067] In addition, the pressure control device also includes a piston block 81, which is arranged inside the fixed tube 61 and abuts against the inner wall of the fixed tube 61. The water pump 84 injects water above the piston block 81, so that the pressure inside the fixed tube 61 can be changed by injecting water, that is, controlling the movement of the piston block 81. The water can also be used to heat the fixed tube 61, thereby heating the spiral wind forming area 614. Among them, the degree to which the pressure of the fixed tube 61 is increased by controlling the movement of the piston block 81 with water pressure is much higher than the degree to which the pressure of the fixed tube 61 is increased by the pressure applied to the piston block 81 by the counterweight block. Therefore, a better pressure control effect can be achieved.

[0068] During normal use, the piston block 81 can be located at a relatively low position in the fixed tube 61, so that the hot water in the fixed tube 61 can be more heat-exchanged with the fluorine gas in the spiral wind forming area 614 through the fixed tube 61 and the heat sink 82. When it is necessary to control the pressure in the reaction liquid, the piston block 81 can be moved up and then down, thereby achieving the effect of increasing the pressure in the reaction liquid and at the same time taking into account the function of heating the spiral wind forming area 614.

[0069] Specifically, the driving shaft in this embodiment is only located at the lower portion of the fixed tube 61 , and the length of the driving shaft is limited so that the piston block 81 does not interfere with the driving shaft when moving in the fixed tube 61 . Example 7

[0070] The difference from Example 3 is that the drive motor is arranged at the top of the fixed tube 61. A sealing plate 612 is provided at the top of the fixed tube 61. The sealing plate 612 has a through-hole formed in the middle and a communication port formed at the edge thereof. The water supply pipe 83 is connected to the communication port. The drive shaft passes through the through-hole and is fixed to the spiral conveying piece 631 at the bottom of the fixed tube 61.

[0071] When the drive motor is arranged below the fixed tube 61, the drive shaft needs to pass through the lower end of the fixed tube 61, and the lower part of the fixed tube 61 will contain the reaction liquid. After a long period of use, problems will occur in the sealing between the drive shaft and the lower end of the fixed tube 61, which will cause leakage of the reaction liquid. The leakage of the reaction liquid will overlook the surrounding parts and cause great economic losses.

[0072] When the driving motor is arranged above the fixed pipe 61, even if leakage occurs, it is water that leaks outward, which can better protect the surrounding components. Example 8

[0073] The difference from Example 6 is that the pressure control structure 8 further includes a backup pump body 86 and a backup pipe 87 based on Example 6. The backup pipe 87 is connected to the fixed pipe 61, and the backup pump body 86 is connected to the water tank 85. The backup pump body 86 is used to add water in the fixed pipe 61 to the water tank 85, so that the water is added to the fixed pipe 61 and then discharged from the fixed pipe 61. The water forms a water flow in the fixed pipe 61 and flows in one direction. The drive shaft extends to the upper part of the fixed pipe 61, and the piston block 81 is tightly sealed against the drive shaft. The drive shaft can rotate relative to the piston block 81. The drive shaft is provided with a spiral blade 88, which drives the drive shaft to rotate under the action of the water flow. The backup pump body 86 and the water pump 84 are both located on the ground, which is more convenient for maintenance and can also better ensure the sealing of the fixed pipe 61 to avoid leakage.

[0074] In other embodiments, a reaction liquid injection pipe 9 is further provided. The reaction liquid injection pipe 9 directly penetrates the reaction tower 2 at the top of the reaction tower 2 and drips the reaction liquid onto the defluorination filler 3 at the top of the reaction tower 2. In this case, the defluorination filler 3 is located above all the outlets 611, so that hot water can pass through the fixed pipe 61 to better exchange heat with the spiral wind forming area 614 below the defluorination filler 3.

[0075] In other solutions, the reaction liquid in the reaction tower will fall to the bottom of the reaction tower. By setting corresponding pipelines and pumps at the bottom of the reaction tower, the reaction liquid is re-added to the reactor 1, thereby realizing the recycling of the reaction liquid and collecting the defluorinated phosphoric acid in the reactor 1. In other solutions, a discharge port can also be directly set in the reaction tower 2 to discharge and collect the reaction liquid, and the reaction liquid can be re-added to the reactor 1 at regular intervals. Example 9

[0076] This embodiment provides a method for defluorination of wet-process dilute phosphoric acid.

[0077] The defluorination method of wet-process phosphoric acid dilute acid includes: adding phosphate slurry and sulfuric acid into a reactor 1; forming multiple air inlet areas 51 for outputting axial flow wind through a fluorine gas conveying member 5, so that the fluorine gas conveying member 5 forms a spiral wind along the length direction of a fixed axis 7; forming multiple discharge ports 611 along the extension direction of the fixed axis 7 through a reaction liquid conveying member 6, so that the reaction liquid is discharged into the spiral wind in the form of mist; the spiral wind carries the mist reaction liquid upward and passes through the defluorination filler 3 in the reaction tower 2; the discharge port 611 also discharges the reaction liquid above the defluorination filler 3, so that the reaction liquid on the defluorination filler 3 flows downward.

[0078] One of the implementation principles of the wet-process phosphoric acid dilute acid defluorination device and method of the present application is: adding phosphate slurry and sulfuric acid into a reactor 1 for reaction to obtain a reaction liquid and fluorine gas.

[0079] The reaction liquid is connected to the fixed tube 61 by the action of the connecting tube 62. The power structure 632 drives the spiral conveying piece 631 to rotate, thereby placing the portion of the fixed tube 61 connected to the connecting tube 62 and the connecting tube 62 under negative pressure, thereby conveying the reaction liquid into the fixed tube 61. The height difference between the reactor 1 and the fixed tube 61 can also be utilized to allow the reaction liquid to flow into the fixed tube 61. The rotation of the spiral conveying piece 631 will continuously add the reaction liquid to the fixed tube 61, and then the reaction liquid will be discharged outward through the discharge port 611 in the fixed tube 61.

[0080] The fluorine gas is fed into the fixed pipe 61 by the action of the fluorine gas pump body 53 and the fluorine gas axial flow fan 54 , and then forms a spiral wind in the fixed pipe 61 .

[0081] The reaction liquid is discharged from the outlet 611 and then added to the spiral wind. Thus, the reaction liquid flows along with the spiral wind, and the reaction liquid and fluorine gas can react directly. The unreacted part passes through the defluorination filler 3 and further reacts, thereby increasing the defluorination and defluorination effects.

[0082] In addition, when there is enough reaction liquid in the fixed tube 61, the pressure control structure 8 can apply pressure to or reduce the pressure of the fixed tube 61, and then the pressure in the fixed tube 61 will increase or decrease, thereby increasing or decreasing the pressure of the reaction liquid discharged outward from the outlet 611.

[0083] Finally, the fluorine gas in the reaction tower 2 will be discharged into the treatment tower 4 to be treated to prevent environmental pollution.

[0084] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A defluorination device for wet-process phosphoric acid dilute acid, characterized in that: include: A reactor is used to add phosphate slurry and sulfuric acid to generate reaction liquid and fluorine gas; The reaction tower is used to receive the reaction liquid and fluorine gas through a conveying assembly, and add the fluorine gas and the reaction liquid into the reaction tower; A defluorination filler is arranged at the upper part of the reaction tower; Wherein, the conveying assembly includes: a fluorine gas conveying component and a reaction liquid conveying component; The fluorine gas conveying member forms a plurality of air inlet areas for outputting axial flow wind at the bottom of the reaction tower; the plurality of air inlet areas are distributed in a circular array around a fixed axis, so that the fluorine gas conveying member forms a spiral wind along the length direction of the fixed axis; The reaction liquid conveying member is formed with a plurality of discharge ports along the extension direction of the fixed axis for discharging the reaction liquid into the spiral wind in the form of mist; Part of the discharge port is located above the defluorination filler; The defluorination filler is provided with a plurality of inclined slots; the extension direction of the inclined slots matches the spiral direction of the spiral wind, so that when the spiral wind enters the inclined slots, the flow direction of the spiral wind is the same as the guide direction of the inclined slots; A liquid receiving area is formed above the defluorination filler; the liquid receiving area is used to receive the reaction liquid and fill the reaction liquid into the chute; The projection of the chute on the end surface of the defluorination filler is constructed to have an arc-shaped edge line and a straight edge line; the arc-shaped edge line and the straight edge line are connected; The spiral wind has a spiral wind forming area and a spiral wind shaping area in the reaction tower; A temperature control component is provided in the reaction tower, and the temperature control component is used to form a heating area in the spiral wind forming area to increase the temperature of the fluorine gas.

2. A defluorination device for wet-process phosphoric acid dilute acid according to claim 1, characterized in that: The reaction liquid conveying member includes: a fixed pipe and a connecting pipe; the connecting pipe is used to connect the fixed pipe with the reactor so that the reaction liquid in the reactor is added to the fixed pipe; The fixed tube is used to form an infusion channel and the discharge port communicated with the infusion channel; the discharge port is located on the side wall of the fixed tube; A driving member is provided on the fixed tube, and the driving member is used to add the reaction liquid into the fixed tube and discharge the reaction liquid outwardly from the discharge port.

3. A defluorination device for wet-process phosphoric acid dilute acid according to claim 2, characterized in that: The fixed pipe portion is located outside the reaction tower; The driving member includes: a spiral conveying piece and a power structure for driving the spiral conveying piece to rotate; The spiral conveying piece is located at the lower part of the fixed tube; the spiral conveying piece abuts against the inner wall surface of the fixed tube.

4. A defluorination device for wet-process phosphoric acid dilute acid according to claim 3, characterized in that: The spiral conveying piece is arranged at the lower part of the fixed tube, and a pressure control structure is arranged at the upper part of the fixed tube. The pressure control structure is used to increase and decrease the pressure of the infusion cavity in the fixed tube.

5. The defluorination device for wet-process phosphoric acid dilute acid according to claim 1, characterized in that: An inlet and an outlet are also formed on the defluorination filler; the inlet and the outlet are both connected to the edge of the chute; An injection port is also formed on the defluorination filler; the injection port is communicated with the middle of the chute.

6. A defluorination device for wet-process phosphoric acid dilute acid according to claim 5, characterized in that: Along the fixed axis direction, the inclined groove has multiple circles in the defluorination filler; the injection port penetrates the multiple circles of the inclined groove, so that multiple layers of reaction liquid films in contact with fluorine gas are formed in the inclined groove.

7. A defluorination method using the defluorination device for wet-process phosphoric acid dilute acid according to any one of claims 1 to 6, characterized in that: include: Adding phosphate slurry and sulfuric acid into the reactor; A plurality of air inlet areas for outputting axial flow wind are formed by the fluorine gas conveying member, so that the fluorine gas conveying member forms a spiral wind along the length direction of the fixed axis; A plurality of discharge ports are formed along the extension direction of the fixed axis by the reaction liquid conveying member, so that the reaction liquid is discharged into the spiral wind in the form of mist; The spiral wind carries the mist reaction liquid upward and leads to the defluorination filler in the reaction tower; The discharge port also allows the reaction liquid to be discharged above the defluorination filler, so that the reaction liquid on the defluorination filler flows downward.

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