Ardealite double-reverse flotation purification system and process

Abstract

The invention provides a novel ardealite double-reverse flotation purification system and process, and the system comprises a size mixing tank which is used for mixing ardealite slurry; the first dosing container is communicated with the downstream of the size mixing tank; the first reverse flotation column is communicated with the downstream of the first dosing container, and a first outer guide hopper is arranged outside the top end of the first reverse flotation column and used for guiding materials overflowing from the top of the first reverse flotation column outwards; the second dosing container is communicated with the downstream of the first reverse flotation column; the second reverse flotation column is communicated with the downstream of the second dosing container, and a second outer guide hopper is arranged outside the top end of the second reverse flotation column and used for guiding materials overflowing from the top of the second reverse flotation column outwards; and the first filter press is communicated with the downstream of the second reverse flotation column and is used for carrying out filter pressing on materials at the bottom of the second reverse flotation column.

Description

Technical Field

[0001] The invention belongs to the technical field of phosphogypsum processing and relates to a system and process for double reverse flotation purification of phosphogypsum. Background Art

[0002] Phosphogypsum comes primarily in two colors: gray-black and off-white. Its particle diameter typically ranges from 5 to 50 μm, with a crystalline water content of 20% to 25%. Phosphogypsum is a solid waste generated during the wet-process phosphoric acid process. Its primary component is calcium sulfate dihydrate. Phosphogypsum has a complex composition, including calcium sulfate, incompletely decomposed phosphate rock, residual phosphoric acid, fluoride, acid-insoluble matter, and organic matter. The presence of fluorine and organic matter has the greatest impact on the resource utilization of phosphogypsum. The indiscriminate discharge and accumulation of phosphogypsum has severely damaged the ecological environment, polluting groundwater resources and wasting land resources.

[0003] At present, the flotation process of phosphogypsum is an important step in the purification of phosphogypsum. However, the existing phosphogypsum flotation process has some shortcomings. For example, some processes cannot effectively remove large particles of impurities in the slurry that cannot be separated by flotation, affecting product quality; when using the positive flotation process, the yield of phosphogypsum is relatively low and the tailings are high. Summary of the Invention

[0004] The purpose of the present invention is to provide a new system and process for double reverse flotation purification of phosphogypsum.

[0005] In order to achieve the above technical effects, the present invention provides a system for double reverse flotation purification of phosphogypsum, comprising:

[0006] A slurry mixing tank, which is used to mix phosphogypsum slurry;

[0007] a first dosing container, the first dosing container being in communication with the downstream of the slurry mixing tank;

[0008] a first reverse flotation column, the first reverse flotation column being in communication with the downstream of the first dosing container, and a first outer guide hopper being provided on the outer top of the first reverse flotation column for guiding outward the material overflowing from the top of the first reverse flotation column;

[0009] a second dosing container, the second dosing container being in communication with a downstream portion of the first reverse flotation column;

[0010] a second reverse flotation column, the second reverse flotation column being in communication with the downstream of the second dosing container, and a second outer guide hopper being provided on the outer top of the second reverse flotation column for guiding the material overflowing from the top of the second reverse flotation column outward;

[0011] A first filter press is communicated with the downstream of the second reverse flotation column and is used for filter pressing the material at the bottom of the second reverse flotation column.

[0012] The present invention is further configured to further include a buffer tank, wherein the upstream of the buffer tank is communicated with the downstream of the slurry mixing tank, and the downstream of the buffer tank is communicated with the first dosing container.

[0013] The present invention is further configured to include a storage tank, the capacity of the storage tank is larger than the buffer tank, the upstream of the storage tank is communicated with the downstream of the buffer tank, and the downstream of the storage tank is communicated with the first dosing container.

[0014] The present invention is further configured to include a screening structure, which is located between the storage tank and the first dosing container and is used to screen the material and allow the material passing through the screening structure to enter the first dosing container.

[0015] The present invention is further configured such that the screening structure comprises:

[0016] A supporting base, wherein a plurality of the supporting bases are vertically arranged, and a supporting spring is vertically arranged on the top of each supporting base;

[0017] A centralizing bucket, the centralizing bucket is in the shape of a trumpet with an upward opening, a material blocking member with a U-shaped cross section is provided on the top of the centralizing bucket, the opening of the material blocking member faces downstream, a third outer guide bucket is provided at the open end of the material blocking member, and the centralizing bucket is connected to the top ends of all the support springs;

[0018] A filter element, the filter element is arranged at the bottom of the material blocking element in an inclined shape, and the material in the storage tank is introduced into the top of the filter element during screening, and the third outer guide bucket is used to guide the material filtered by the filter element outward;

[0019] The receiving bucket has an opening at the bottom of the centralizing bucket for introducing the material passing through the filter into the receiving bucket, and the material in the receiving bucket is used to be introduced into the first dosing container.

[0020] The present invention is further configured such that the filter element includes a first filter portion and a second filter portion located downstream of the first filter portion, the first filter portion is porous, and the second filter portion includes:

[0021] A plurality of support columns are horizontally arranged on the inner wall of the material stopper, and an L-shaped end portion is provided at the bottom of each support column, and the bottoms of the end portions on two adjacent support columns are facing each other;

[0022] A hinged column, the hinged column being horizontally arranged on the inner wall of the material blocking member, and each of the two adjacent support columns is provided with a hinged column;

[0023] Filter strips, each hinge column is vertically hinged with a plurality of spaced filter strips. When the bottom of the top of the filter strip abuts against the upper side of the bottom of the corresponding termination part, the bottom of the filter strip is in a separated state from the corresponding termination part. When the bottom of the bottom of the filter strip abuts against the upper side of the bottom of the corresponding termination part, the top of the filter strip is in a separated state from the corresponding termination part.

[0024] The present invention is further configured such that an inertia portion is provided on the lower side of the filter strip, and the inertia portion is located upstream or downstream of the corresponding hinge column.

[0025] The present invention is further configured to include a separation trough, which is used to receive the material flowing into the second outer guide bucket. The separation trough includes a cylindrical upper separation part and a conical lower separation part that is larger at the top and smaller at the bottom. The material of the second outer guide bucket is introduced into the middle part of the upper separation part. The top of the upper separation part is open, and a fourth outer guide bucket is provided on the outside of the top of the upper separation part. The material at the bottom of the lower separation part is used to be introduced into the first dosing container.

[0026] The present invention is further configured to include:

[0027] a centralizing tank, into which the materials in the first outer guide hopper, the third outer guide hopper, and the fourth outer guide hopper are all introduced;

[0028] a second filter press, the second filter press being used to filter the material in the centralizing tank;

[0029] a first temporary storage tank, the first temporary storage tank being used to store the filtrate filtered out of the second filter press;

[0030] a plurality of infusion tubes, wherein the input ends of the infusion tubes are all connected to the first temporary storage tank, the output end of at least one of the infusion tubes is used to input filtrate to the screening structure, the output end of at least one of the infusion tubes is used to input filtrate to the first reverse flotation column, and the output end of at least one of the infusion tubes is used to input filtrate to the second reverse flotation column;

[0031] The second temporary storage tank, the output end of the first filter press is connected to a first branch pipe, a second branch pipe and a third branch pipe, the first branch pipe, the second branch pipe and the third branch pipe are all provided with valves, the first branch pipe is used to discharge the filtrate filtered out of the first filter press, the second branch pipe is used to introduce the liquid for cleaning the material in the first filter press into the slurry mixing tank, the output end of the third branch pipe is connected to the second temporary storage tank, and the second temporary storage tank is used to store the liquid for cleaning the material in the first filter press, and the second temporary storage tank is connected to the cleaning input end of the first filter press through a pipeline.

[0032] The present invention also provides a process for a double reverse flotation purification system for phosphogypsum as described in any one of the above items, comprising the following steps:

[0033] S1, mixing phosphogypsum raw materials and water in a slurry mixing tank to obtain phosphogypsum slurry;

[0034] S2, the slurry is introduced into the first dosing container, a flotation agent is added and stirred and mixed with the slurry;

[0035] S3, the slurry mixed with the flotation reagent is introduced into the first reverse flotation column, and bubbles are injected into the first reverse flotation column at the same time, wherein the injection point of the bubbles is lower than the inflow point of the slurry;

[0036] S4, part of the material overflows from the top of the first reverse flotation column and flows into the first outer guide bucket and then discharged outward, and the remaining part of the material flows into the second dosing container through the bottom of the first reverse flotation column;

[0037] S5, adding flotation reagent into the second dosing container and stirring and mixing;

[0038] S6, the slurry mixed with the flotation reagent is introduced into the second reverse flotation column, and bubbles are injected into the second reverse flotation column at the same time, wherein the injection point of the bubbles is lower than the inflow point of the slurry;

[0039] S7, part of the material overflows from the top of the second reverse flotation column and flows into the second outer guide bucket and then is discharged outward, and the remaining part of the material flows into the first filter press through the bottom of the second reverse flotation column;

[0040] S8, the first filter press filters the inflowing material to separate the filtrate from the material.

[0041] Compared with the prior art, the present invention provides a system and process for double reverse flotation purification of phosphogypsum. During the purification of phosphogypsum, the phosphogypsum raw material and water are first stirred in a slurry mixing tank to obtain phosphogypsum slurry; the slurry is then introduced into a first dosing container, a flotation agent (i.e., reverse flotation agent, the same below) is added and stirred with the slurry; the slurry mixed with the flotation agent is then introduced into a first reverse flotation column, and bubbles are simultaneously injected into the first reverse flotation column, wherein the bubble injection point is lower than the slurry inflow point; part of the material overflows through the top of the first reverse flotation column and flows into the first outer guide bucket. The slurry is then discharged outwards, and the remaining part of the material flows into the second dosing container through the bottom of the first reverse flotation column; flotation reagent is added to the second dosing container and stirred and mixed; the slurry mixed with the flotation reagent is introduced into the second reverse flotation column, and bubbles are injected into the second reverse flotation column at the same time, wherein the injection point of the bubbles is lower than the inflow point of the slurry; part of the material overflows out through the top of the second reverse flotation column and flows into the second outer guide bucket and then discharged outwards, and the remaining part of the material flows into the first filter press through the bottom of the second reverse flotation column; the first filter press filters the inflowing material to separate the filtrate and the material. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a schematic flow diagram of the present invention;

[0043] Figure 2 This is a schematic diagram of the structure of the present invention Figure 1 ;

[0044] Figure 3 yes Figure 2 Enlarged view of part A;

[0045] Figure 4 yes Figure 2 Enlarged view of part B;

[0046] Figure 5 yes Figure 4 Enlarged view of part C;

[0047] Figure 6 yes Figure 4 Enlarged view of part D in the middle;

[0048] Figure 7 This is a schematic diagram of the structure of the present invention Figure 2 ;

[0049] Figure 8 yes Figure 7 Enlarged view of part E in the middle;

[0050] Figure 9 is a cross-sectional view of the first reverse flotation column of the present invention;

[0051] Figure 10Schematic diagram of the separation tank of the present invention;

[0052] Figure 11 is a schematic diagram of the screening structure of the present invention;

[0053] Figure 12 yes Figure 11 Enlarged view of part F;

[0054] Figure 13 is a cross-sectional view of the screening structure of the present invention;

[0055] Figure 14 yes Figure 13 Enlarged view of section G;

[0056] Figure 15 yes Figure 13 Enlarged view of section H;

[0057] Figure 16 It is a schematic diagram of the support column part of the present invention;

[0058] Figure 17 yes Figure 16 Enlarged view of the middle J section;

[0059] Figure 18 Schematic diagram of the filter strip of the present invention.

[0060] Among them, 1. slurry mixing tank; 2. first dosing container; 3. first reverse flotation column; 4. first outer guide bucket; 5. second dosing container; 6. second reverse flotation column; 7. second outer guide bucket; 8. first filter press; 9. buffer tank; 10. storage tank; 11. support base; 12. support spring; 13. concentration bucket; 14. material blocking member; 15. third outer guide bucket; 16. filter element; 16a. first filter part; 16b. second filter part; 16b1. support column; 16b2. termination part; 16b3. hinged column; 16b4. filter strip; 16b5. inertia part; 17. separation tank; 17a. upper separation part; 17b. lower separation part; 18. fourth outer guide bucket; 19. second temporary storage tank; 20. first branch pipe; 21. second branch pipe; 22. third branch pipe. DETAILED DESCRIPTION

[0061] The following describes in further detail a system and process for double reverse flotation purification of phosphogypsum proposed by the present invention, with reference to the accompanying drawings and specific embodiments. The advantages and features of the present invention will become more apparent from the following description. It should be noted that the drawings are highly simplified and not to exact scale, and are intended solely to facilitate and clearly illustrate the embodiments of the present invention. Identical or similar reference numerals in the drawings represent identical or similar components.

[0062] A double reverse flotation purification system for phosphogypsum, such as Figures 1 to 18Shown, including:

[0063] A slurry mixing tank 1, which is used to mix phosphogypsum slurry;

[0064] a first dosing container 2, the first dosing container 2 being in communication with the downstream of the slurry mixing tank 1;

[0065] a first reverse flotation column 3, which is in communication with the downstream of the first dosing container 2; a first outer guide hopper 4 is provided on the top of the first reverse flotation column 3 to guide the material overflowing from the top of the first reverse flotation column 3 outward;

[0066] a second dosing container 5 , the second dosing container 5 being in communication with the downstream of the first reverse flotation column 3 ;

[0067] a second reverse flotation column 6, which is in communication with the downstream of the second dosing container 5; a second outer guide hopper 7 is provided on the top of the second reverse flotation column 6 for guiding the material overflowing from the top of the second reverse flotation column 6 outward;

[0068] The first filter press 8 is communicated with the downstream of the second reverse flotation column 6 and is used for filtering the material at the bottom of the second reverse flotation column 6 .

[0069] A buffer tank 9 is also included. The upstream of the buffer tank 9 is communicated with the downstream of the slurry mixing tank 1 , and the downstream of the buffer tank 9 is communicated with the first dosing container 2 .

[0070] The storage tank 10 is also included. The capacity of the storage tank 10 is larger than that of the buffer tank 9 . The upstream of the storage tank 10 is communicated with the downstream of the buffer tank 9 , and the downstream of the storage tank 10 is communicated with the first dosing container 2 .

[0071] A screening structure is also included, which is located between the storage tank 10 and the first dosing container 2 and is used to screen the material and allow the material passing through the screening structure to enter the first dosing container 2.

[0072] The screening structure comprises:

[0073] A supporting base 11, wherein a plurality of supporting bases 11 are vertically provided, and a supporting spring 12 is vertically provided on the top of each supporting base 11;

[0074] A centralizing bucket 13 is in the shape of a trumpet with an upward opening. A material blocking member 14 with a U-shaped cross section is provided on the top of the centralizing bucket 13. The opening of the material blocking member 14 faces downstream. A third outer guide bucket 15 is provided at the open end of the material blocking member 14. The centralizing bucket 13 is connected to the top ends of all the support springs 12.

[0075] The filter element 16 is provided at an angle at the bottom of the material retaining member 14. During screening, the material in the storage tank 10 is introduced into the top of the filter element 16. The third outer guide hopper 15 is used to guide the material filtered by the filter element 16 outward.

[0076] The receiving bucket, the bottom of the central bucket 13 is provided with an opening for introducing the material passing through the filter 16 into the receiving bucket, and the material in the receiving bucket is used to be introduced into the first dosing container 2.

[0077] The filter element 16 includes a first filter portion 16a and a second filter portion 16b located downstream of the first filter portion 16a. The first filter portion 16a is porous, and the second filter portion 16b includes:

[0078] Support columns 16b1, wherein a plurality of support columns 16b1 are horizontally arranged on the inner wall of the material stopper 14, and an L-shaped end portion 16b2 is provided at the bottom of each support column 16b1, and the bottoms of the end portions 16b2 on two adjacent support columns 16b1 are facing each other;

[0079] A hinge column 16b3, which is horizontally arranged on the inner wall of the material blocking member 14, and a hinge column 16b3 is provided between each of two adjacent support columns 16b1;

[0080] Filter strip 16b4, each hinge column 16b3 is vertically hinged with a plurality of filter strips 16b4 in an interval shape. When the bottom of the top end of the filter strip 16b4 abuts against the upper side of the bottom of the corresponding termination portion 16b2, the bottom end of the filter strip 16b4 and the corresponding termination portion 16b2 are in a separated state. When the bottom of the bottom end of the filter strip 16b4 abuts against the upper side of the bottom of the corresponding termination portion 16b2, the top end of the filter strip 16b4 and the corresponding termination portion 16b2 are in a separated state.

[0081] An inertia portion 16b5 is provided on the lower side of the filter strip 16b4, and the inertia portion 16b5 is located upstream or downstream of the corresponding hinge column 16b3.

[0082] It also includes a separation trough 17, which is used to receive the material flowing into the second outer guide hopper 7. The separation trough 17 includes a cylindrical upper separation part 17a and a conical lower separation part 17b that is larger at the top and smaller at the bottom. The material of the second outer guide hopper 7 is introduced into the middle part of the upper separation part 17a. The top of the upper separation part 17a is open, and a fourth outer guide hopper 18 is provided outside the top of the upper separation part 17a. The material at the bottom of the lower separation part 17b is used to be introduced into the first dosing container 2.

[0083] Also included are:

[0084] A centralizing tank, into which the materials in the first outer guide bucket 4, the third outer guide bucket 15 and the fourth outer guide bucket 18 are all introduced;

[0085] a second filter press, the second filter press being used to filter the material in the centralizing tank;

[0086] a first temporary storage tank, the first temporary storage tank being used to store the filtrate filtered out of the second filter press;

[0087] a plurality of infusion tubes, wherein the input ends of the infusion tubes are all connected to the first temporary storage tank, the output end of at least one of the infusion tubes is used to input filtrate to the screening structure, the output end of at least one of the infusion tubes is used to input filtrate to the first reverse flotation column 3, and the output end of at least one of the infusion tubes is used to input filtrate to the second reverse flotation column 6;

[0088] The second temporary storage tank 19, the output end of the first filter press 8 is connected to a first branch pipe 20, a second branch pipe 21 and a third branch pipe 22, the first branch pipe 20, the second branch pipe 21 and the third branch pipe 22 are all provided with valves, the first branch pipe 20 is used to discharge the filtrate filtered out of the first filter press 8, the second branch pipe 21 is used to introduce the liquid for cleaning the material in the first filter press 8 into the slurry mixing tank 1, the output end of the third branch pipe 22 is connected to the second temporary storage tank 19, and the second temporary storage tank 19 is used to store the liquid for cleaning the material in the first filter press 8, and the second temporary storage tank 19 is connected to the cleaning input end of the first filter press 8 through a pipeline.

[0089] The present invention also discloses a process for a double reverse flotation purification system for phosphogypsum as described in any one of the above items, comprising the following steps:

[0090] S1, mixing phosphogypsum raw materials and water in a slurry mixing tank 1 to obtain phosphogypsum slurry;

[0091] S2, the slurry is introduced into the first dosing container 2, a flotation agent is added and stirred and mixed with the slurry;

[0092] S3, the slurry mixed with the flotation reagent is introduced into the first reverse flotation column 3, and bubbles are injected into the first reverse flotation column 3 at the same time, wherein the injection point of the bubbles is lower than the inflow point of the slurry;

[0093] S4, part of the material overflows through the top of the first reverse flotation column 3, flows into the first outer guide hopper 4 and is then discharged outward, and the remaining part of the material flows through the bottom of the first reverse flotation column 3 into the second dosing container 5;

[0094] S5, adding flotation reagent into the second dosing container 5 and stirring and mixing;

[0095] S6, the slurry mixed with the flotation reagent is introduced into the second reverse flotation column 6, and bubbles are injected into the second reverse flotation column 6 at the same time, wherein the injection point of the bubbles is lower than the inflow point of the slurry;

[0096] S7, part of the material overflows through the top of the second reverse flotation column 6, flows into the second outer guide hopper 7 and is then discharged outward, and the remaining part of the material flows through the bottom of the second reverse flotation column 6 into the first filter press 8;

[0097] S8, the first filter press 8 performs filter pressing on the inflowing material to separate the filtrate from the material.

[0098] The present invention provides a system and process for double reverse flotation purification of phosphogypsum. During the purification of phosphogypsum, the phosphogypsum raw material and water are first stirred in a slurry mixing tank 1 to obtain phosphogypsum slurry. The slurry is then introduced into a first dosing container 2, and a flotation agent (i.e., reverse flotation agent, the same below) is added and stirred with the slurry. The slurry mixed with the flotation agent is then introduced into a first reverse flotation column 3, and bubbles are simultaneously injected into the first reverse flotation column 3, wherein the bubble injection point is lower than the slurry inflow point. Part of the material overflows through the top of the first reverse flotation column 3 and flows into a first outer guide hopper 4 before being discharged outward. The remaining material flows into the second dosing container 5 through the bottom of the first reverse flotation column 3; a flotation agent is added to the second dosing container 5 and stirred to mix; the slurry mixed with the flotation agent is introduced into the second reverse flotation column 6, and bubbles are injected into the second reverse flotation column 6 at the same time, wherein the bubble injection point is lower than the slurry inflow point; part of the material overflows through the top of the second reverse flotation column 6 and flows into the second outer guide hopper 7 and is then discharged outward, and the remaining material flows into the first filter press 8 through the bottom of the second reverse flotation column 6; the first filter press 8 performs filter pressure on the inflowing material to achieve separation of the filtrate and the material.

[0099] The tops of the slurry mixing tank 1, the buffer tank 9, the storage tank 10, the first dosing container 2, the second dosing container 5 and the separation tank 17 in this application are all provided with stirring motors, and the output shafts of the stirring motors are all provided with stirring tanks, so as to enable the materials in each container to be mixed more quickly and evenly. At the same time, the first reverse flotation column 3 and the second reverse flotation column 6 have the same structure, both including a tank body with an overflow port at the top and a pipe at the bottom for discharging material to the next process. At the same time, the reslurry tank, the buffer tank 9, and the storage tank 10 are all connected by pipes, and the pipes can be installed with a delivery pump (or gravity flow material, the same below) according to actual conditions. The material in the storage tank 10 is then input to the top of the first filter part 16a through a pipe for wet screening of the material. The material filtered by the first filter part 16a and the second filter part 16b enters the collecting bucket 13 and then flows into the receiving bucket. Thereafter, the receiving bucket, the first dosing container 2, the first reverse flotation column 3, the second dosing container 5, and the second reverse flotation column 6 are all connected by pipes, and the pipes can be installed with a delivery pump according to actual conditions.

[0100] The material at the bottom of the second reverse flotation column 6 is then pumped into the first filter press 8 for filtration. Both the first filter press 8 and the second filter press (not shown) are common commercially available plate and frame filter presses. The material overflowing from the top of the second reverse flotation column 6 is directed through the fourth outer guide 18 into the separation tank 17, where it undergoes separation. The overflow flows into the centralization tank. Simultaneously, the material discharged from the first and third outer guides 4 and 15 also flows into the centralization tank. The second filter press then filters the material in the centralization tank. The filtrate is replenished through a liquid feed line to the screening structure, the first dosing container 2, and the second dosing container 5, where it is used to dilute the slurry and facilitate reverse flotation. At the same time, the added water can also flush the pipes and prevent blockages. Moreover, the added water is at a higher position. After being added to the first reverse flotation column 3 and the second reverse flotation column 6, it can also flush the floating materials. In this way, even if some materials are lifted, the required materials can be better separated from the bubbles, reducing material waste and improving the material recovery rate. In this application, the filtrate of the tailings is used to replenish the water for the screening structure, the first reverse flotation column 3, and the second reverse flotation column 6, thereby improving the material recovery rate.

[0101] The present application uses two reverse flotation processes on the slurry, and the overflow from the first reverse flotation contains more impurities, so it is directly introduced into the second filter press for filtration, and the tailings filtered out by the second filter press are directly sent out for processing. During the second reverse flotation, the overflow contains a certain amount of recyclable materials. At this time, the material in the second reverse flotation column 6 is introduced into the separation tank 17, and further separation is achieved in the separation tank 17, so that the overflow at the top of the separation tank 17 enters the second filter press for filtration, thereby recovering useful materials to the greatest extent; while the material at the bottom contains a relatively large proportion of useful materials, this part of the material can be introduced into the first dosing container 2 and undergo two reverse flotation processes again, thereby further improving the recycling effect of the material.

[0102] The material in the slurry mixing tank 1 has poor stirring and mixing uniformity. In this case, the mixed material (for example, the slurry in the middle and / or top of the slurry mixing tank 1) can be introduced into the buffer tank 9. In this way, the uniformity of the material in the buffer tank 9 is improved. Secondly, the material in the buffer tank 9 can be introduced into the storage tank 10 for temporary storage. The storage tank 10 has a large capacity (only for illustration in the figure), which serves as a storage warehouse. In this way, the upstream slurry mixing tank 1 and buffer tank 9 can both operate continuously or intermittently, and then the slurry is introduced into the storage tank 10. Since there is more slurry in the storage tank 10, it can ensure that the subsequent processes can be carried out continuously and stably.

[0103] When the slurry enters the first filter section 16a, it contains a large number of large particles and the amount of slurry is also large. Therefore, the first filter section 16a is fixedly connected to the material retaining member 14, ensuring its structural strength and allowing large particles to be filtered out stably. Subsequently, the amount of slurry decreases and flows into the second filter section 16b. Because the filter strips 16b4 are strip-shaped and flow in the same direction as the slurry, the resistance to large particles and the slurry is low, allowing both large particles and the slurry to flow downward. However, because the filter strips 16b4 are spaced apart, they also ensure sufficient openings for the slurry to pass through. That is, the slurry and small particles can pass smoothly and efficiently through the second filter section 16b, while large particles can smoothly flow downward to the third outer guide hopper 15 and enter the collection tank.

[0104] During the filtration process, a vibrating motor is installed at the bottom of the collecting bucket 13, which can drive the collecting bucket 13, the material retaining member 14, and the filter element 16 to vibrate up and down, accelerating the filtration process. It also breaks up the granular material, reducing waste and facilitating subsequent reverse flotation. Furthermore, because the middle portion of the filter strip 16b4 is hinged to the hinge post 16b3 and its ends do not completely contact the end portions 16b2 at either end, the filter strip 16b4 will exhibit irregular up and down swinging during the filtration process, effectively preventing material from getting stuck between adjacent filter strips 16b4 and ensuring normal and efficient filtration. Furthermore, because the bottom of the filter strip 16b4 has an inertia portion 16b5, the inertia portion 16b5 increases the vibration effect of the filter strip 16b4 during the up and down filtration process, further preventing blockages. In another embodiment, the entire filter element 16 is shaped like a porous plate, i.e., the shape of the first filter portion 16a.

[0105] After the material in the second reverse flotation column 6 enters the first filter press 8, the material is filter-filtered, and the filtrate from the filter press is directly discharged to other plant buildings for recycling; subsequently, the first filter press 8 needs to be rinsed twice, wherein the liquid from the first rinse is led back to the pulping tank 1 for pulping (if there is not enough water, conventional reclaimed water can be used for pulping), and the water from the second rinse is introduced into the second temporary storage tank 19, and then when the material is rinsed for the next time, the washing water in the second temporary storage tank 19 (that is, the second washing water of the previous rinse) is used to wash the material in the first filter press 8 for the first time (the washing water will be led back to the pulping tank 1), that is, except for the water used for the first rinse of the first filter press 8, the other materials are rinsed twice, and the water after the two rinses is led back to the pulping tank 1, which can recover the required substances (such as phosphorus and acid) to the greatest extent.

[0106] It should also be noted that all references to "disposed" and similar descriptors in this application (especially in this specification) express that two structures have or exist in a connection relationship. However, the specific means by which the two structures are connected are not particularly limited, and are generally conventional connection means. In other words, such means should be understood as existing in the art and do not require further elaboration. For example, "n is disposed on m" simply expresses that structure n is present on structure m, while the two are specifically connected by welding, riveting, adhesive bonding, or integral molding, all of which are within the scope of protection of this application. Another example is "y is rotatably disposed on x" simply expresses that y and x are rotatable relative to each other, while whether the two are connected by a bearing, y directly passes through x and is rotatably connected to x, or other feasible methods are all within the scope of protection of this application.

[0107] The above description is only a description of the preferred embodiments of the present invention and does not limit the scope of the present invention. Any changes and modifications made by ordinary technicians in the field of the present invention based on the above disclosure shall fall within the scope of protection of the claims.

Claims

1. A double reverse flotation purification system for phosphogypsum, characterized in that: include: A slurry mixing tank (1), wherein the slurry mixing tank (1) is used to mix phosphogypsum slurry; a first dosing container (2), the first dosing container (2) being in communication with the downstream of the slurry mixing tank (1); a first reverse flotation column (3), the first reverse flotation column (3) being in communication with the downstream of the first dosing container (2), and a first outer guide hopper (4) being provided on the outside of the top of the first reverse flotation column (3) for guiding the material overflowing from the top of the first reverse flotation column (3) outward; a second dosing container (5), the second dosing container (5) being in communication with the downstream of the first reverse flotation column (3); a second reverse flotation column (6), the second reverse flotation column (6) being in communication with the downstream of the second dosing container (5), and a second outer guide hopper (7) being provided on the outside of the top of the second reverse flotation column (6) for guiding the material overflowing from the top of the second reverse flotation column (6) outward; A first filter press (8) is connected to the downstream of the second reverse flotation column (6) and is used for filtering the material at the bottom of the second reverse flotation column (6).

2. A double reverse flotation purification system for phosphogypsum according to claim 1, characterized in that: It also includes a buffer tank (9), the upstream of the buffer tank (9) is communicated with the downstream of the slurry mixing tank (1), and the downstream of the buffer tank (9) is communicated with the first dosing container (2).

3. A double reverse flotation purification system for phosphogypsum according to claim 2, characterized in that: The device further comprises a storage tank (10), the capacity of the storage tank (10) being greater than that of the buffer tank (9), the upstream of the storage tank (10) being in communication with the downstream of the buffer tank (9), and the downstream of the storage tank (10) being in communication with the first dosing container (2).

4. A double reverse flotation purification system for phosphogypsum according to claim 3, characterized in that: It also includes a screening structure, which is located between the storage tank (10) and the first dosing container (2) and is used to screen the material and allow the material passing through the screening structure to enter the first dosing container (2).

5. A double reverse flotation purification system for phosphogypsum according to claim 4, characterized in that: The screening structure comprises: A supporting base (11), wherein a plurality of the supporting bases (11) are vertically arranged, and a supporting spring (12) is vertically arranged on the top of each supporting base (11); A centralizing bucket (13) is in the shape of a trumpet with an opening facing upwards, a material blocking member (14) with a U-shaped cross section is provided on the top of the centralizing bucket (13), the opening of the material blocking member (14) faces downstream, a third outer guide bucket (15) is provided at the open end of the material blocking member (14), and the centralizing bucket (13) is connected to the top ends of all the support springs (12); A filter element (16) is provided at the bottom of the material blocking element (14) in an inclined shape. During screening, the material in the storage tank (10) is introduced into the top of the filter element (16). The third outer guide hopper (15) is used to guide the material filtered by the filter element (16) outwards. A receiving bucket, wherein the bottom of the centralizing bucket (13) is provided with an opening for introducing the material passing through the filter element (16) into the receiving bucket, and the material in the receiving bucket is used to be introduced into the first dosing container (2).

6. A double reverse flotation purification system for phosphogypsum according to claim 5, characterized in that: The filter element (16) comprises a first filter portion (16a) and a second filter portion (16b) located downstream of the first filter portion (16a), wherein the first filter portion (16a) is porous, and the second filter portion (16b) comprises: A plurality of support columns (16b1) are horizontally arranged on the inner wall of the material blocking member (14); an L-shaped end portion (16b2) is provided at the bottom of each support column (16b1); the bottoms of the end portions (16b2) on two adjacent support columns (16b1) are facing each other; A hinge column (16b3), the hinge column (16b3) being horizontally arranged on the inner wall of the material blocking member (14), and a hinge column (16b3) being provided between each of two adjacent support columns (16b1); A filter strip (16b4), each hinge column (16b3) is vertically hinged with a plurality of spaced filter strips (16b4), when the bottom of the top of the filter strip (16b4) abuts against the upper side of the bottom of the corresponding termination portion (16b2), the bottom of the filter strip (16b4) and the corresponding termination portion (16b2) are in a separated state, and when the bottom of the bottom of the filter strip (16b4) abuts against the upper side of the bottom of the corresponding termination portion (16b2), the top of the filter strip (16b4) and the corresponding termination portion (16b2) are in a separated state.

7. A double reverse flotation purification system for phosphogypsum according to claim 6, characterized in that: An inertia portion (16b5) is provided on the lower side of the filter strip (16b4), and the inertia portion (16b5) is located upstream or downstream of the corresponding hinge column (16b3).

8. The double reverse flotation purification system for phosphogypsum according to claim 5, characterized in that: The invention also includes a separation trough (17), wherein the separation trough (17) is used to receive the material flowing into the second outer guide hopper (7), and the separation trough (17) includes a cylindrical upper separation portion (17a) and a conical lower separation portion (17b) which is larger at the top and smaller at the bottom. The material of the second outer guide hopper (7) is introduced into the middle of the upper separation portion (17a), the top of the upper separation portion (17a) is open, and a fourth outer guide hopper (18) is provided outside the top of the upper separation portion (17a), and the material at the bottom of the lower separation portion (17b) is used to be introduced into the first dosing container (2).

9. A double reverse flotation purification system for phosphogypsum according to claim 8, characterized in that: Also included are: A centralizing tank, into which materials in the first outer guide bucket (4), the third outer guide bucket (15), and the fourth outer guide bucket (18) are all introduced; a second filter press, the second filter press being used to filter the material in the centralizing tank; a first temporary storage tank, the first temporary storage tank being used to store the filtrate filtered out of the second filter press; a plurality of infusion tubes, wherein the input ends of the infusion tubes are all connected to the first temporary storage tank, the output end of at least one of the infusion tubes is used to input filtrate to the screening structure, the output end of at least one of the infusion tubes is used to input filtrate to the first reverse flotation column (3), and the output end of at least one of the infusion tubes is used to input filtrate to the second reverse flotation column (6); A second temporary storage tank (19), the output end of the first filter press (8) is connected to a first branch pipe (20), a second branch pipe (21) and a third branch pipe (22), the first branch pipe (20), the second branch pipe (21) and the third branch pipe (22) are all provided with valves, the first branch pipe (20) is used to discharge the filtrate filtered out of the first filter press (8), the second branch pipe (21) is used to introduce the liquid for cleaning the material in the first filter press (8) into the slurry mixing tank (1), the output end of the third branch pipe (22) is communicated with the second temporary storage tank (19), and the second temporary storage tank (19) is used to store the liquid for cleaning the material in the first filter press (8), and the second temporary storage tank (19) is communicated with the cleaning input end of the first filter press (8) through a pipeline.

10. A process for the double reverse flotation purification of phosphogypsum according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1, mixing phosphogypsum raw materials and water in a slurry mixing tank (1) to obtain phosphogypsum slurry; S2, the slurry is introduced into the first dosing container (2), a flotation agent is added and stirred and mixed with the slurry; S3, the slurry mixed with the flotation reagent is introduced into the first reverse flotation column (3), and bubbles are injected into the first reverse flotation column (3), wherein the injection point of the bubbles is lower than the inflow point of the slurry; S4, part of the material overflows from the top of the first reverse flotation column (3), flows into the first outer guide bucket (4), and is then discharged outward, while the remaining part of the material flows into the second dosing container (5) through the bottom of the first reverse flotation column (3); S5, adding a flotation agent into the second dosing container (5) and stirring and mixing; S6, the slurry mixed with the flotation reagent is introduced into the second reverse flotation column (6), and bubbles are injected into the second reverse flotation column (6), wherein the injection point of the bubbles is lower than the inflow point of the slurry; S7, part of the material overflows from the top of the second reverse flotation column (6), flows into the second outer guide hopper (7) and is then discharged outward, and the remaining part of the material flows through the bottom of the second reverse flotation column (6) into the first filter press (8); S8, the first filter press (8) performs filter pressing on the inflowing material to separate the filtrate from the material.

Images