Fluorine reduction device and method for dilute acid of wet-process phosphoric acid

Abstract

The invention relates to the field of wet-process phosphoric acid defluorination, and particularly discloses a wet-process phosphoric acid dilute acid defluorination device and a method thereof.The device comprises a reaction kettle used for adding phosphoric ore pulp and sulfuric acid and generating reaction liquid and fluorine gas; a reaction tower; the defluorination filler is arranged at the upper part of the reaction tower; a fluorine gas conveying part and a reaction liquid conveying part; a plurality of air inlet areas for outputting axial flow air are formed at the bottom of the reaction tower by the fluorine conveying piece; the plurality of air inlet areas are distributed around a fixed axis in a circumferential array manner, so that the fluorine conveying piece forms spiral air along the length direction of the fixed axis; a plurality of discharge ports for discharging the reaction liquid into the spiral air in a vaporific form are formed in the reaction liquid conveying piece along the extension direction of the fixed axis. The method has the advantages that the defluorination or defluorination speed is increased, and the fluorine recovery rate is increased.

Description

Technical Field

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

[0002] Wet-process phosphoric acid defluorination mainly uses phosphate slurry and sulfuric acid to treat in a reactor, then uses the reaction liquid in the reactor to spray the tail gas in the reactor, and absorbs fluorine in a spray tower to achieve defluorination; after the reaction is completed, defluorinated phosphoric acid is obtained from the reactor, and the fluorine gas is recycled in the form of defluorinated phosphoric acid. The tail gas is mainly fluorine gas.

[0003] When the reaction liquid is used to spray the tail gas, the reaction liquid and fluorine gas are mainly used to pass through the defluorination filler, and the two are fully contacted in a countercurrent manner to fully recover the fluorine gas. The reaction liquid will form a liquid film in the pores of the defluorination filler. The liquid film is the liquid gathered in the pores. As the reaction liquid continuously flows into and out of the pores, the reaction liquid will fill the pores, and then the fluorine gas will pass through the pores and blow the reaction liquid away, which can increase the degree of contact between the fluorine gas and the reaction liquid; 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. Then 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 fluorination reduction rate and a low fluorine gas recovery rate. Summary of the invention

[0004] In order to improve the slow defluorination or fluorination reduction speed and the low recovery rate of fluorine gas, the present application provides a defluorination device for wet-process phosphoric acid dilute acid.

[0005] The present application provides a wet-process phosphoric acid dilute acid defluorination device that adopts the following technical solution: A defluorination device for wet-process phosphoric acid dilute acid comprises: 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 into 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 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 into the spiral wind in the form of mist; some of the discharge ports are located above the defluorination filler.

[0006] By adopting the above technical scheme, fluorine gas flows 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. The reaction liquid conveying part is arranged in this empty area, 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 the fluorine gas, so that the reaction liquid absorbs the fluorine gas more time, and the degree of the reaction of the two is more thorough. The arrangement of the partial discharge port 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 the fluorine gas passes through the defluorination filler. The moment the liquid film is broken, multiple droplets will splash, so that the reaction liquid is mixed into multiple corners in the fluorine gas, so that the fluorine gas and the reaction liquid react better. In addition, since the discharge port will discharge the reaction liquid into the spiral wind, the fluorine gas can be prevented from contacting the discharge port, thereby avoiding the discharge port from being corroded by fluorine gas, and the use effect can be guaranteed for a long time and the service life can be improved. 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 from 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.

[0007] Optionally, the reaction liquid conveying member 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 can be added into the fixed tube; the fixed tube is used to form an infusion channel and the discharge port connected to 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 outward at the discharge port.

[0008] By adopting the above technical solution, the 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, so as to be quickly added to the spiral wind.

[0009] Optionally, the fixed tube portion is located outside the reaction tower; the driving member includes: a spiral conveying plate and a power structure for driving the spiral conveying plate to rotate; the spiral conveying plate is located at the lower part of the fixed tube; the spiral conveying plate abuts against the inner wall surface of the fixed tube.

[0010] By adopting the above technical solution, the driving part adopts a spiral conveying piece arranged in a fixed tube. Then, after a long time of use, due to the long-term contact with the reaction liquid, even if the spiral conveying piece 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 parts of the pump body will be easily corroded after a long time of use, resulting in leakage, wear and other problems. In addition, acidic liquids may also accelerate scaling and clogging inside the pump body, reducing the efficiency of the water pump. The design of the spiral conveying piece can avoid the appearance of seals and bearings and other parts, and scaling and clogging on the spiral conveying piece will not affect its normal use due to the large pores of the spiral cavity on the spiral conveying piece.

[0011] Optionally, the spiral conveying sheet 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.

[0012] By adopting the above technical solution, the lower part of the fixed pipe is a spiral conveying piece. As the spiral conveying piece rotates continuously, the reaction liquid will be gradually transported upward from the bottom of the fixed pipe until the height of the reaction liquid exceeds the spiral piece. However, due to the continuous rotation of the spiral piece, the reaction liquid will be continuously added to the fixed pipe, regardless of the height of the spiral piece. After the height of the reaction liquid in the fixed pipe reaches a certain position, the pressure control structure applies pressure to the upper part of the fixed pipe, which will cause the reaction liquid in the fixed pipe to be squeezed outward. At this time, the reaction liquid in the fixed pipe will increase the force of the reaction liquid in the fixed pipe to be discharged outward at the discharge port under the action of the conveying force provided by the spiral conveying piece and the pressure provided by the pressure control structure. Therefore, when the rotation speed of the spiral conveying piece reaches the maximum, the speed of drainage at the discharge port can also be increased by the pressure control structure.

[0013] Optionally, a plurality of inclined grooves are provided on the defluorination filler; the extension direction of the inclined grooves matches the spiral direction of the spiral wind, so that when the spiral wind enters the inclined grooves, the flow direction of the spiral wind is the same as the guide direction of the inclined grooves; 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 grooves.

[0014] By adopting the above technical solution, the setting of the inclined slot 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 inclined slot is the same as the flow direction of the spiral wind, so the spiral wind will not encounter resistance when passing through the inclined slot, and the fluorine gas can better pass through the inclined slot, thereby further increasing the degree of complete contact between the fluorine gas and the reaction liquid and increasing the degree of defluorination.

[0015] Optionally, the projection of the inclined groove 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.

[0016] By adopting the above technical solution, the inclined groove is in an arc shape, which can further increase the contact time between the fluorine gas and the defluorination filler, and also increase the contact time between the fluorine gas and the reaction liquid.

[0017] 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.

[0018] By adopting the above technical solution, the injection port is connected with the middle part of the chute, so the reaction liquid can penetrate into the middle part of the chute through the injection port, thereby forming a liquid film in the middle part of the chute. Since the reaction liquid discharged from the discharge port is below the defluorination filler, the reaction liquid enters the chute along 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 directly falls on the defluorination filler, thereby forming a liquid film on the inlet, thereby forming a multi-layer liquid film in the chute, which greatly increases the contact time between the fluorine gas and the reaction liquid, and the effect of the defluorination filler on the defluorination and defluorination process.

[0019] Optionally, 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.

[0020] 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, so that more liquid films will be formed in the chute, and the time for fluorine gas to pass through the chute will be increased, thereby improving the degree of defluorination and fluorine reduction of fluorine gas.

[0021] 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 heat the fluorine gas.

[0022] 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 to avoid the problem of increased corrosiveness caused by the temperature rise of the fluorine gas, thereby avoiding the problem of corrosion of the discharge port of the fixed tube due to excessive corrosiveness when the fluorine gas contacts the discharge port on the fixed tube.

[0023] 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 through a reaction liquid conveying member along the extension direction of the fixed axis, 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 to 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.

[0024] In summary, the present application includes at least one of the following beneficial technical effects: 1. While the fluorine gas is being treated by the defluorination filler, the fluorine gas is collected under the defluorination filler in the form of 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 the multiple discharge ports formed along the fixed axis. The spiral wind carries the mist reaction liquid through the defluorination filler, so that the fluorine gas can be in contact with the reaction liquid for a long time, which increases the speed of fluorine gas treatment and the efficiency of fluorine gas recovery. 2. The fluorine gas carrying the mist reaction liquid passes through the defluorination filler, which makes the mist reaction liquid contact with the reaction liquid in the pores of the defluorination filler, so that the liquid film formed in the defluorination filler is blown away, and the mist reaction liquid can cooperate with the reaction liquid on the defluorination filler to re-form a liquid film; 3. By discharging the reaction liquid from the middle to the surroundings, the fluorine gas of the spiral wind will not contact the discharge port, thereby ensuring that the discharge port will not be corroded and increasing the service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is an overall schematic diagram according to an embodiment of the present application; Figure 2 It is a structural schematic diagram of a part of the embodiment, mainly showing the Figure 1 structure; Figure 3 It is a structural schematic diagram of a part of the embodiment, mainly showing the structure inside the reaction tower; Figure 4 It is a structural schematic diagram of a part of the embodiment, mainly showing the Figure 2 structure; Figure 5 It is a structural schematic diagram of a part of the embodiment, mainly showing the structure inside the fixed tube, which is shown in an exploded view; Figure 6 It is a schematic structural diagram of a part of the embodiment, mainly showing the structure of the solution of embodiment 8; Figure 7It is a schematic diagram of the structure of a part of the embodiment, mainly showing the structure inside the reaction tower of embodiment 8; Figure 8 It is a schematic structural diagram of a part of the embodiment, mainly showing the structure inside the fixed tube of embodiment 8; Fig. 9 yes Figure 8 A magnified view of part A Fig.10 It is a schematic structural diagram of a part of the embodiment, mainly showing the structure of the defluorinated filler; Fig.11 It is a structural schematic diagram of a part of the embodiment, mainly showing the structure of the fixed pipe, the heat sink and some surrounding parts; Fig.12 It is a structural diagram of a part of the embodiment, mainly showing Figure 1 The cross-sectional structure of Fig.13 It is a structural schematic diagram of a part of the embodiment, mainly showing the Fig.12 structure; Fig.14 yes Fig.13 A magnified view of part B Fig.15 It is a structural diagram of a part of the embodiment, mainly showing Figure 6 The cross-sectional structure of Fig.16 yes Fig.15 Enlarged view of part C Fig.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.

[0026] Reference numerals: 1. Reactor; 2. Reaction tower; 3. Defluorination filler; 31. Inclined trough; 32. Arc edge line; 33. Straight edge line; 34. Injection port; 4. Treatment tower; 5. Fluorine gas conveying parts; 51. Air inlet area; 52. Fluorine gas conveying pipe; 53. Fluorine gas pump body; 54. Fluorine gas axial flow fan; 6. Reaction liquid conveying parts; 61. Fixed pipe; 611. Discharge port; 612. Sealing plate; 613. Spiral wind forming area; 614. Spiral wind forming area; 62. Connecting pipe; 63. Driving part; 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 pipe; 84. Water pump; 85. Water tank; 86. Spare pump body; 87. Spare pipe; 88. Spiral blade; 9. Reaction liquid injection pipe. DETAILED DESCRIPTION

[0027] The following is combined with Figure 1-17This application is described in further detail.

[0028] 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 overflowing outward.

[0029] Specifically, the reactor 1 is used to add phosphate slurry and sulfuric acid, and the reactor 1 stirs the phosphate slurry and sulfuric acid to generate reaction liquid and fluorine gas, the reaction liquid is collected at the bottom of the reactor 1, and the fluorine gas is collected at the top of the reactor 1. The reaction tower 2 is used to receive the reaction liquid and fluorine gas through a conveying component, and add the fluorine gas and the reaction liquid to the reaction tower 2. The defluorination filler 3 is arranged on the upper part of the reaction tower 2.

[0030] The conveying assembly includes: a fluorine gas conveying member 5 and a reaction liquid conveying member 6. The fluorine gas conveying member 5 forms a plurality of air intake areas 51 for outputting axial flow wind at the bottom of the reaction tower 2, and the plurality of air intake areas 51 are distributed in a circular array around a fixed axis 7, so that the fluorine gas conveying member 5 forms a spiral wind along the length direction 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, wherein 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, and the fluorine gas pump body 53 is used to evacuate air so that the force of fluorine gas being discharged into the reaction tower 2 is large enough. The fluorine gas axial flow fan 54 is arranged at the outlet of the fluorine gas conveying pipe 52. The outlet of the fluorine gas conveying pipe 52 is arranged in plurality, that is, the outlet of the fluorine gas conveying pipe 52 is the air intake area 51, and the air intake area 51 refers to the fluorine gas added to the reaction tower 2. The multiple outlets of the fluorine gas delivery pipe 52 are realized by dividing the fluorine gas delivery pipe 52 into a main pipeline and multiple branch pipelines, and each branch pipeline represents 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 arranged 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 against each other, so that a spiral wind will be formed in the reaction tower 2 after the multi-channel fluorine gas blows against each other. The spiral wind is mainly distributed in the edge area of ​​the reaction tower 2, and an empty area will be formed in the middle of the reaction tower 2. This empty area is the location of the fixed axis 7.

[0031] The reaction liquid conveying member 6 forms a plurality of discharge ports 611 for discharging the reaction liquid in the form of mist into the spiral wind along the extension direction of the fixed axis 7. 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 a discharge port 611, which is a hole on the side wall of the fixed pipe 61 or a nozzle arranged at the end of the fixed pipe 61. The nozzle discharges 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.

[0032] By adopting the above technical solution, the fluorine gas flows upward in a spiral manner in the reaction tower 2, and then an empty area is formed in the middle of the fluorine gas. The objects in this empty area will be sucked into the spiral wind under the action of air pressure. The reaction liquid conveying member 6 is arranged in this empty area to discharge the reaction liquid outward, so that the reaction liquid can flow quickly into the spiral wind, and the spiral wind will slow down the flow speed of the fluorine gas in the reaction tower 2, thereby increasing the contact time between the reaction liquid and the fluorine gas, so that the reaction liquid absorbs the fluorine gas more time, and the degree of reaction between the two is more thorough. The arrangement of the partial discharge port 611 above the defluorination filler 3 is to form a liquid film of the reaction liquid in the defluorination filler 3. When the fluorine gas passes through the defluorination filler, the liquid film needs to be broken. At the moment when the liquid film is broken, multiple droplets will splash, so that the reaction liquid is mixed into multiple corners of the fluorine gas, so that the fluorine gas and the reaction liquid react better. In addition, the present application discharges the reaction liquid into the spiral wind because the discharge port 611 can prevent the fluorine gas from contacting the discharge port 611, thereby preventing the discharge port 611 from being corroded by the fluorine gas, and can ensure the use effect and improve the service life for a long time. Mix part of the reaction liquid with the fluorine gas below the defluorination filler 3, 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 break 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 a pore will appear. 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 increasing the degree of contact reaction between the fluorine gas and the reaction liquid when the fluorine gas breaks through the liquid film.

[0033] 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

[0034] The difference between the reaction liquid conveying member 6 and the embodiment 1 is as follows: The reaction liquid conveying 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. 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.

[0035] The specific solution for the driving member 63 is: 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, so after the reaction liquid is added to the spiral conveying piece 631, the spiral conveying piece 631 contacts the reaction liquid, and the spiral conveying piece 631 rotates, which will transport the reaction liquid. In addition, the spiral conveying piece 631 abuts against the inner wall of the fixed tube 61, so in the process of transporting the reaction liquid, the reaction liquid can no longer overflow from the edge of the spiral conveying piece 631, so that the spiral conveying piece 631 is used to transport the reaction liquid in the fixed tube 61. According to the rotation direction of the spiral conveying piece 631, the reaction liquid can be transported from bottom to top or from top to bottom. It is preferred that the reaction liquid is added to the bottom of the fixed tube 61 and then transported from bottom to top.

[0036] The advantage of using the spiral conveying sheet 631 is that after a long time of use, due to long-term contact with the reaction liquid, even if corrosion occurs, the normal use of the spiral conveying sheet 631 can still be guaranteed. On the contrary, if a pump body is used, the seals, bearings and other parts of the pump body will be easily corroded after a long time of use, resulting in leakage, wear and other problems. In addition, the acidic liquid may also accelerate the scaling and clogging inside the pump body, reducing the efficiency of the water pump 84. The design of the spiral conveying sheet 631 can avoid the appearance of seals and bearings and other parts, and scaling and clogging on the spiral conveying sheet 631 will not affect its normal use due to the large pores of the spiral cavity on the spiral conveying sheet 631.

[0037] 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 sheet 631, and the drive motor is connected to the drive shaft through the transmission component, so that the drive motor drives the spiral conveying sheet 631 to rotate through the transmission component and the drive shaft.

[0038] Among them, the transmission component adopts one of gear transmission, belt transmission and chain transmission. Example 3

[0039] The difference between the reaction liquid conveying member 6 and the embodiment 2 is that: The spiral conveying sheet 631 is disposed at the lower part of the fixed tube 61. A pressure control structure 8 is disposed at the upper part of the fixed tube 61, and the pressure control structure 8 is used to increase and decrease the pressure of the infusion cavity in the fixed tube 61.

[0040] 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 arranged on the piston block 81. The winch is arranged on the ground, the piston block 81 is arranged 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 winding around the guide wheel. The winch drives the piston block 81 to move up through the rope, or the winch loosens part of the rope and the weight of the counterweight to move the piston block 81 down. In this way, it is convenient to repair the winch when a fault occurs, and the reaction tower 2 also has a certain height, so compared with some other control methods, it can avoid high-altitude maintenance.

[0041] Since the lower part of the fixed pipe 61 is the spiral conveying piece 631, as the spiral conveying piece 631 rotates continuously, the reaction liquid will be gradually transported upward from the lower part of the fixed pipe 61 until the height of the reaction liquid exceeds the spiral piece, but due to the continuous rotation of the spiral piece, the reaction liquid will be continuously added to the fixed pipe 61, regardless of the height of the spiral piece. After the height of the reaction liquid in the fixed pipe 61 reaches a certain position, the piston block 81 moves downward to apply pressure to the reaction liquid in the fixed pipe 61, so that the reaction liquid in the fixed pipe 61 is squeezed outward. At this time, the reaction liquid in the fixed pipe 61 is increased by the conveying force provided by the spiral conveying piece 631 and the pressure provided by the pressure control structure 8. The force of the reaction liquid in the fixed pipe 61 to be discharged outward at the discharge port 611 increases, so that when the rotation speed of the spiral conveying piece 631 reaches the maximum, the pressure control structure 8 can also be used to increase the speed of drainage from the discharge port 611. Example 4

[0042] The difference between defluorinated filler 3 and Example 1 is: A plurality of inclined grooves 31 are provided on the defluorination filler 3; the extension direction of the inclined grooves 31 matches the spiral direction of the spiral wind, so that when the spiral wind enters the inclined grooves 31, the flow direction of the spiral wind is the same as the flow direction of the inclined grooves 31. A liquid receiving area is formed above the defluorination filler 3; the liquid receiving area is used to receive the reaction liquid and fill the reaction liquid into the inclined grooves 31. The projection of the inclined grooves 31 on the end surface of the defluorination filler 3 is constructed to have an arc-shaped edge line 32 and a straight edge line 33; the arc-shaped edge line 32 and the straight edge line 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 be matched with 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, by utilizing the inclined grooves 31 and the distribution of the inclined grooves 31 along the arc, the time for the fluorine gas to pass through the defluorination filler 3 is increased, and the effect of the liquid film formed by the fluorine gas and the reaction liquid on the defluorination filler 3 is increased.

[0043] In other embodiments, an inlet and an outlet are formed on the defluorination filler 3; the inlet and the outlet are both connected to the edge of the chute 31; an injection port 34 is formed on the defluorination filler 3; the injection port 34 is connected to the middle of the chute 31. The injection port 34 is opened perpendicular to the end of the defluorination filler 3. Along the direction of the fixed axis 7, the chute 31 has multiple turns in the defluorination filler 3; the injection port 34 penetrates multiple turns of the chute 31, so that multiple layers of reaction liquid films in contact with fluorine gas are formed in the chute 31.

[0044] 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 discharged from the outlet 611 is 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 directly falls on the defluorination filler 3, thereby forming a liquid film on the inlet, thereby forming a multi-layer liquid film in the chute 31. The injection port 34 will have multiple connected positions 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 defluorination of the fluorine gas. Example 5

[0045] 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 out and blown together through the fluorine gas axial flow fan 54, and a spiral wind is being formed. 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 outside the reaction tower 2, and multiple circles of heating tubes can also be wound inside the reaction tower 2, so that the spiral wind forming area 614 will be heated. After the spiral wind is formed, the spiral wind is heated again. When the fluorine gas does not form a spiral wind, the fluorine gas will contact the fixed tube 61. At this time, the fluorine gas is not heated to avoid the problem of increased corrosiveness caused by the temperature increase of the fluorine gas, thereby avoiding the problem of fluorine gas corroding the outlet 611 of the fixed tube 61 due to excessive corrosiveness when the fluorine gas contacts the outlet 611 on the fixed tube 61. Example 6

[0046] The difference from Example 5 is that: The temperature control component is a heat sink 82 disposed 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 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.

[0047] 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 fixed tube 61 can also be heated by water, thereby heating the spiral wind forming area 614. Among them, the degree of increasing the pressure of the fixed tube 61 by controlling the movement of the piston block 81 with water pressure is much higher than the degree of increasing the pressure of the fixed tube 61 by applying pressure to the piston block 81 by the counterweight block. Therefore, a better effect of pressure control can be achieved.

[0048] 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 exchange heat 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.

[0049] Specifically, the driving shaft in this embodiment is only located at the lower part 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

[0050] The difference from Example 3 is that: The driving motor is arranged at the top of the fixed tube 61. A sealing plate 612 is arranged at the top of the fixed tube 61, a through hole is formed in the middle of the sealing plate 612, a connecting port is formed at the edge of the sealing plate 612, the water delivery pipe 83 is connected to the connecting port, and the driving shaft passes through the through hole and is fixed to the spiral conveying sheet 631 at the bottom of the fixed tube 61.

[0051] When the driving motor is arranged below the fixed tube 61, the driving 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 time of use, problems will occur in the sealing between the driving 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.

[0052] 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

[0053] The difference from Example 6 is that: The pressure control structure 8 further includes a spare pump body 86 and a spare pipe 87 on the basis of Example 6. The spare pipe 87 is connected to the fixed pipe 61, and the spare pump body 86 is connected to the water tank 85. The spare pump body 86 is used to add the water in the fixed pipe 61 to the water tank 85, so that the water will be added to the fixed pipe 61 and then discharged from the fixed pipe 61. The water will form a water flow in the fixed pipe 61 and flow in one direction. The driving shaft extends to the upper part of the fixed pipe 61, and the piston block 81 is tightly sealed against the driving shaft. The driving shaft can rotate relative to the piston block 81. The driving shaft is provided with a spiral blade 88, and the spiral blade 88 will drive the driving shaft to rotate under the action of the water flow. The spare pump body 86 and the water pump 84 are both arranged on the ground, so as to be more convenient for maintenance, and at the same time, the sealing of the fixed pipe 61 can be better guaranteed to avoid leakage.

[0054] In other schemes, a reaction liquid injection pipe 9 is further provided, and the reaction liquid injection pipe 9 directly penetrates into the reaction tower 2 at the top of the reaction tower 2, and the reaction liquid is dripped onto the defluorination filler 3 at the top of the reaction tower 2. At this time, the defluorination filler 3 is located above all the discharge ports 611, so that the hot water can be better heat-exchanged with the spiral wind forming area 614 below the defluorination filler 3 through the fixed pipe 61.

[0055] In other schemes, the reaction liquid in the reaction tower will fall to the bottom of the reaction tower, and by setting corresponding pipelines and pumps at the bottom of the reaction tower, the reaction liquid is added back to the reactor 1, so as to realize the recycling of the reaction liquid and collect the defluorinated phosphoric acid in the reactor 1. In other schemes, a discharge port can also be directly set in the reaction tower 1 to discharge and collect the reaction liquid outward, and the reaction liquid can be added back to the reactor 1 at a regular time. Example 9

[0056] This embodiment provides a method for defluorination of wet-process dilute phosphoric acid.

[0057] The defluorination method of wet-process phosphoric acid dilute acid includes: adding phosphate slurry and sulfuric acid into a reactor 1; forming a plurality of 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 a plurality of 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.

[0058] One of the implementation principles of the wet-process phosphoric acid dilute acid defluorination device and method of the present application is: Phosphate slurry and sulfuric acid are added into the reactor 1 to react and obtain a reaction liquid and fluorine gas.

[0059] The reaction liquid will be connected to the fixed pipe 61 under the action of the connecting pipe 62, and the power structure 632 drives the spiral conveying piece 631 to rotate, so that the part of the fixed pipe 61 that is connected to the connecting pipe 62 and the connecting pipe 62 are in a negative pressure state, thereby conveying the reaction liquid to the fixed pipe 61. The height difference between the reactor 1 and the fixed pipe 61 can also be used to make the reaction liquid flow into the fixed pipe 61, and the rotation of the spiral conveying piece 631 will continuously add the reaction liquid to the fixed pipe 61, and then the reaction liquid will be discharged to the outside through the discharge port 611 in the fixed pipe 61.

[0060] Under the action of the fluorine gas pump body 53 and the fluorine gas axial flow fan 54 , the fluorine gas is added into the fixed pipe 61 , and then a spiral wind is formed in the fixed pipe 61 .

[0061] The reaction liquid is discharged from the outlet 611 and then added to the spiral wind, so that the reaction liquid flows along with the spiral wind, the reaction liquid and the fluorine gas can react directly, and the unreacted part passes through the defluorination filler 3 and further reacts, thereby increasing the defluorination and defluorination effects.

[0062] 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 discharge port 611.

[0063] Finally, the fluorine gas in the reaction tower 2 will be discharged into the treatment tower 4 to treat the fluorine gas and prevent environmental pollution.

[0064] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A defluorination device for wet-process phosphoric acid dilute acid, characterized in that: include: A reactor, used to add phosphate slurry and sulfuric acid and generate reaction liquid and fluorine gas; A reaction tower, used for receiving the reaction liquid and the fluorine gas through a conveying assembly, and adding 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 comprises: a fluorine gas conveying component and a reaction liquid conveying component; 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 into the spiral wind in the form of mist; Part of the discharge port is located above the defluorination filler.

2. A defluorination device for wet-process phosphoric acid dilute acid according to claim 1, characterized in that: The reaction liquid conveying member comprises: 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 can be added to the fixed pipe; The fixed tube is used to form an infusion channel and the outlet communicated with the infusion channel; the outlet is located on the side wall of the fixed tube; A driving member is arranged on the fixed tube, and the driving member is used to add the reaction liquid into the fixed tube and discharge the reaction liquid outward 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 pipe; the spiral conveying piece abuts against the inner wall surface of the fixed pipe.

4. A defluorination device for wet-process phosphoric acid dilute acid according to claim 3, characterized in that: The spiral conveying sheet 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. A defluorination device for wet-process phosphoric acid dilute acid according to any one of claims 1 to 4, characterized in that: A plurality of inclined grooves are provided on the defluorination filler; the extending direction of the inclined grooves matches the spiral direction of the spiral wind, so that when the spiral wind enters the inclined grooves, the flow direction of the spiral wind is the same as the guide direction of the inclined grooves; 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.

6. A defluorination device for wet-process phosphoric acid dilute acid according to claim 5, characterized in that: The projection of the inclined groove 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.

7. A defluorination device for wet-process phosphoric acid dilute acid according to claim 5, 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.

8. A defluorination device for wet-process phosphoric acid dilute acid according to claim 7, 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.

9. A defluorination device for wet-process phosphoric acid dilute acid according to claim 1, characterized in that: The spiral wind has a spiral wind forming area and a spiral wind shaping area in the reaction tower; A temperature control component is arranged 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.

10. A method for defluorination of wet-process phosphoric acid dilute acid, 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 misty reaction liquid upward and flows 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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