Wide-particle-size coal slime high-recovery-rate flotation system and method

Abstract

The invention provides a wide-particle-size-fraction coal slime high-recovery-rate flotation system which comprises a flotation device, the flotation device comprises a flotation tank, an ore feeding opening, a fine particle overflow collecting tank, a foam clean coal collecting tank and two partition plates, the upper area of the flotation tank is divided into three adjacent areas by the two partition plates, and the three adjacent areas are arranged in the flotation tank. The fine particle overflow collecting tank is provided with three areas, the three areas are a first foam area, an overflow area and a second foam area respectively, the number of the foam clean coal collecting tanks is two, and the two foam clean coal collecting tanks are adjacent to the fine particle overflow collecting tank and are communicated with the corresponding first foam area and the second foam area respectively. The invention further discloses a wide-particle-size coal slime high-recovery-rate flotation method. The novel flotation equipment is improved and designed, coarse coal and fine coal can be floated out at the same time by using one flotation equipment under the condition that the recovery rate and the ash content are guaranteed, and additional requirements caused by particle size fraction flotation in the prior art are reduced.

Description

Technical Field

[0001] The invention relates to the technical field of mineral separation and processing, and in particular to a high-recovery flotation system and method for wide-size coal slime. Background Art

[0002] As the conditions of coal mining become more and more complex and large-scale mechanized mining equipment becomes more popular, the slime content in coal preparation plants increases. At present, coal preparation plants mainly reduce the processing volume of flotation and slime water treatment links and improve the slime recovery rate by increasing the recovery of coarse slime and the equipment and process of coarse slime sorting. However, the sorting process is relatively long. If the coarse slime content of some coal preparation plants is low, adding separate recovery and sorting processes will increase production costs and reduce efficiency. In addition, the recovery of coarse particles and fine particles requires completely different flotation fluid mechanics conditions. Fine particles require high stirring intensity and micro-fine bubbles to improve the collision and attachment efficiency of fine particles; while coarse particles require lower stirring intensity and relatively large bubbles to ensure that coarse particles float and do not fall off from the bubbles. There is a certain contradiction between the two, which makes it difficult for existing flotation equipment to achieve flotation recovery of coarse particles and fine particles at the same time. Summary of the invention

[0003] The purpose of the present invention is to overcome the above-mentioned deficiencies in the prior art and provide a wide-size coal slime high recovery rate flotation system and method. By improving and designing a new flotation device, the coarse coal and fine coal can be simultaneously floated out by using one flotation device while ensuring the recovery rate and ash content, thereby reducing the additional need for flotation by particle size classification in the existing process.

[0004] In order to solve the above problems, the present invention provides a high recovery rate flotation system for wide particle size coal slime, characterized in that it comprises a flotation device, the flotation device comprises a flotation tank, a feed port, a fine particle overflow collection tank, a foam clean coal collection tank and a partition, the partition is arranged at the upper part of the flotation tank, one end of the partition is connected to one side of the flotation tank, and the other end of the partition is connected to the other side of the flotation tank, the number of the partitions is two, and the two partitions divide the upper area of ​​the flotation tank into three adjacent areas, and the three areas are respectively a first area, a second area, a third area, a fourth area, a fifth ... A foam zone, an overflow zone and a second foam zone, the feed port is arranged at the inlet of the overflow zone, and the feed port is connected to the overflow zone, the fine particle overflow collecting tank is arranged at the outlet of the overflow zone, and the fine particle overflow collecting tank is connected to the overflow zone, the number of the foam clean coal collecting tanks is two, the two foam clean coal collecting tanks are both arranged on the flotation tank, the two foam clean coal collecting tanks are adjacent to the fine particle overflow collecting tank, and the two foam clean coal collecting tanks are respectively connected to the corresponding first foam zone and the second foam zone.

[0005] The above-mentioned wide particle size coal slime high recovery rate flotation system is characterized in that: the flotation device also includes a false bottom, an impeller stirring mechanism, a flow stabilizer, a frother pipe, a suction pipe, a stator guide plate, a tailings pipe and a foam scraper, the false bottom is arranged at the lower part of the flotation tank, the impeller stirring mechanism is arranged above the false bottom, the number of the flow stabilizer is multiple, and the multiple flow stabilizers are evenly arranged along the circumference of the center of the impeller stirring mechanism, the suction pipe is arranged at the bottom of the impeller stirring mechanism, the lower end of the frother pipe is connected to the suction pipe, the stator guide plate is arranged at the bottom of the impeller stirring mechanism, the tailings pipe is arranged at the bottom of the flotation tank, and the tailings pipe is used to discharge the tailings after sorting in the flotation tank, the foam scraper is arranged above the first foam zone) and the second foam zone, and the foam scraper is used to collect the clean coal floated in the first foam zone) and the second foam zone into the foam clean coal collection tank.

[0006] The above-mentioned wide particle size coal slime high recovery rate flotation system is characterized in that: the wide particle size coal slime high recovery rate flotation system also includes a slurry mixing barrel, the discharge port of the slurry mixing barrel is connected to the ore feeding port through a pipeline, and the slurry mixing barrel is used to stir and mix the coal slime water and the flotation agent.

[0007] The above-mentioned high-recovery flotation system for wide-size coal slime is characterized in that: the high-recovery flotation system for wide-size coal slime also includes a centrifugal dewatering machine, and the feed inlet of the centrifugal dewatering machine is connected to the foam clean coal collection tank.

[0008] The above-mentioned high-recovery flotation system for wide particle size coal slime is characterized in that: the high-recovery flotation system for wide particle size coal slime also includes a flotation column, and the feed inlet of the flotation column is respectively connected to the filtrate outlet of the centrifugal dehydrator and the fine particle overflow collection tank.

[0009] The above-mentioned high-recovery flotation system for wide-size coal slime is characterized in that: the high-recovery flotation system for wide-size coal slime also includes a membrane filter press, and the feed inlet of the membrane filter press is connected to the concentrate outlet of the flotation column.

[0010] The above-mentioned high-recovery flotation system for wide particle size coal slime is characterized in that: the high-recovery flotation system for wide particle size coal slime also includes a concentrator, and the feed inlet of the concentrator is respectively connected to the tailings outlet of the flotation column and the tailings pipeline.

[0011] The present invention also discloses a high recovery rate flotation method for wide particle size coal slime, which is characterized by comprising the following steps:

[0012] Step 1: Slurry preparation: coal slurry water is passed into a slurry mixing barrel at a predetermined flow rate, and flotation reagents are added to the slurry mixing barrel at a predetermined ratio. The stirring mechanism in the slurry mixing barrel stirs and mixes the coal slurry water and the flotation reagents at a preset speed to achieve a selective flocculation and agglomeration effect on the gangue particles in the slurry;

[0013] Step 2: Sorting by a first-stage flotation device, wherein the slurry mixed in step 1 is transported to a flotation device through a ore feeding port, and then flotated by the flotation device. The flotation in the flotation device is a first-stage flotation;

[0014] Step 3, clean coal dehydration. The clean coal in the first flotation foam area in step 2 enters the centrifugal dehydrator for dehydration. The dehydrated product is part of the final clean coal product. The centrifugal liquid merges with the clean coal in the overflow area of ​​the flotation device and enters the flotation column for concentrating.

[0015] Step 4: Second stage flotation column selection. The second stage flotation uses the centrifugal liquid produced by dehydration of the overflow area concentrate and the foam area concentrate of the first stage flotation device as raw material, and further removes the gangue particles to ensure that the ash content of the final clean coal product is further reduced;

[0016] Step 5, second-stage clean coal dehydration, the clean coal product obtained by the second-stage flotation column enters the membrane filter press for dehydration treatment and then passes into the final clean coal product to obtain all the clean coal products, and the membrane filter press removes water and reuses it as circulating water;

[0017] Step six, dehydration of tail coal. The tail coal from the second-stage flotation column and the first-stage flotation device are all concentrated in the concentrator to obtain all the tail coal products. The bottom flow water of the concentrator is reused as circulating water.

[0018] The above-mentioned high recovery rate flotation method for wide particle size coal slime is characterized in that the flotation reagent in step 1 includes a regulator, a dispersant and a flocculant.

[0019] The above-mentioned method for flotation of wide-size coal slime with high recovery rate is characterized in that: the specific steps of sorting by a flotation device in step 1 include:

[0020] The slurry treated by the slurry mixing barrel in step 1 is transported to the overflow area in the flotation tank through the ore feeding port at a predetermined flow rate. Small coal particles are directly overflowed under the action of water flow in the water surface flowing layer, enter the fine-grained overflow collection tank, and become concentrate in the overflow area. Small gangue particles in the slurry sink from the flowing layer to the flotation area under the action of flocculation and agglomeration to participate in the flotation process. Large coal particles and gangue particles in the slurry also sink from the flowing layer together to participate in subsequent flotation.

[0021] The stirring mechanism in the impeller stirring mechanism rotates and generates negative pressure, sucking air, collector and foaming agent from the air and foaming agent pipes, and cutting the air into bubbles of appropriate size, and finally rising to the first foam zone or the second foam zone through the false bottom and the flow stabilizer plate. In the slurry-gas mixing zone, the suction pipe and the stator guide plate suck the slurry for mixing and circulation, so that the coarse coal particles complete mineralization, collide with bubbles of appropriate size and float to the flotation zone and the foam zone, and are finally scraped out by the foam scraper to the foam clean coal collection tank to become the foam zone concentrate. The gangue particles finally enter the tailings pipeline for discharge under the action of the flow field.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] 1. The present invention can ensure that the recovery rate of clean coal in the washed slurry is close to or even exceeds the recovery rate after strict particle size classification by designing a two-stage concentrating process; at the same time, different flotation processes are set according to different particle sizes to achieve the maximum recovery rate of clean coal of different particle sizes.

[0024] 2. The present invention improves and designs a new type of flotation equipment, so that coarse coal and fine coal can be floated out simultaneously with one flotation equipment while ensuring the recovery rate and ash content, effectively widening the flotation width, expanding the coal slime particle size to 1mm, and reducing the additional needs brought by the existing process of particle size grade flotation.

[0025] 3. The present invention can save the need for a large number of flotation machines and transportation pipelines during the design and establishment of a coal preparation plant by simplifying the existing flotation process. The equipment required for the process occupies a smaller area than the existing process equipment, which can save more resources and bring greater economic benefits.

[0026] The invention is further described in detail below through the accompanying drawings and examples. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0028] Figure 1 It is a front view schematic diagram of the structural principle of the flotation device in an embodiment of the present invention.

[0029] Figure 2 It is a left schematic diagram of the structural principle of the flotation device in an embodiment of the present invention.

[0030] Figure 3 It is a schematic diagram of the position and connection relationship of the feed port, fine particle overflow collection tank, foam clean coal collection tank, and partition and flotation tank in the flotation device in an embodiment of the present invention.

[0031] Figure 4 The structure principle flow chart of the high recovery rate flotation system for wide particle size coal slime in the embodiment of the present invention.

[0032] Description of reference numerals:

[0033] 10—flotation device; 11—flotation tank; 12—feeding port; 13—fine particle overflow collection tank;

[0034] 14—foam clean coal collecting tank; 15—partition plate; 16—tailings pipeline; 17—false bottom;

[0035] 18—impeller stirring mechanism; 19—flow stabilizing plate; 20—foaming agent pipeline; 21—suction pipe;

[0036] 22—stator guide plate; 23—first foam area; 24—overflow area; 25—second foam area;

[0037] 30—slurry mixing barrel; 31—centrifugal dehydrator; 32—flotation column; 33—diaphragm filter press;

[0038] 34—Thickener. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] like Figures 1 to 4As shown, the present invention discloses a high recovery rate flotation system for wide particle size coal slime, characterized in that it comprises a flotation device 10, the flotation device 10 comprises a flotation cell 11, a feed port 12, a fine particle overflow collection tank 13, a foam clean coal collection tank 14 and a partition 15, the partition 15 is arranged at the upper part of the flotation cell 11, one end of the partition 15 is connected to one side of the flotation cell 11, and the other end of the partition 15 is connected to the other side of the flotation cell 11, the number of the partitions 15 is two, and the two partitions 15 divide the upper area of ​​the flotation cell 11 into three adjacent areas, and the three areas are respectively a first foam area 23, The overflow zone 24 and the second foam zone 25, the feed port 12 is arranged at the inlet of the overflow zone 24, and the feed port 12 is connected to the overflow zone 24, the fine particle overflow collecting tank 13 is arranged at the outlet of the overflow zone 24, and the fine particle overflow collecting tank 13 is connected to the overflow zone 24, the number of the foamed clean coal collecting tanks 14 is two, the two foamed clean coal collecting tanks 14 are both arranged on the flotation tank 11, the two foamed clean coal collecting tanks 14 are adjacent to the fine particle overflow collecting tank 13, and the two foamed clean coal collecting tanks 14 are respectively connected to the corresponding first foam zone 23 and the second foam zone 25.

[0041] In this embodiment, two oppositely arranged partitions 15 are provided in the flotation device 10. The prepared slurry enters the overflow area 24 from the upper part of one side of the flotation tank 11 through the ore feeding port 12. Since the slurry has a certain flow rate, small coal particles are affected by the water flow in the water surface flowing layer, and enter the fine particle overflow collection tank 13 from the overflow port on the other side of the flotation tank 11 along with the water flow, and become the overflow area concentrate. The small gangue particles in the slurry sink from the fluidized layer to the flotation zone under the action of flocculation and participate in the flotation process. The large coal particles and gangue particles in the slurry also sink from the fluidized layer together and participate in the subsequent flotation. The principle of subsequent flotation is the same as the existing flotation technology. The bubbles at the bottom of the flotation tank 11 rise, collide with the descending medium and large coal particles and gangue particles, and float to the flotation zone and the foam zone, and are finally scraped by the foam scraper to the foam clean coal collection tank 14 to become the foam zone concentrate. The gangue particles finally enter the tailings pipeline 16 for discharge under the action of the flow field. The wide particle size grade coal slime mentioned in the present invention refers to the coal slime with a particle size range of less than 1mm. By improving and designing a new flotation equipment, it is possible to use a flotation equipment to float out coarse coal and fine coal at the same time under the condition of ensuring the recovery rate and ash content, which effectively broadens the width of flotation and reduces the additional needs brought by the existing process particle size grade flotation.

[0042] like Figures 1 to 4 As shown, in this embodiment, the lower part of the area separated by the two oppositely arranged partitions 15 is in an inverted cone shape, which is conducive to the foam rising from the bottom carrying the clean coal into the first foam area 23 and the second foam area 25 on both sides of the overflow area 24.

[0043] like Figure 1 and Figure 2 As shown, the flotation device 10 further includes a false bottom 17, an impeller stirring mechanism 18, a flow stabilizing plate 19, a frother pipe 20, a suction pipe 21, a stator guide plate 22, a tailings pipe 16 and a foam scraper. The false bottom 17 is arranged at the lower part of the flotation tank 11, the impeller stirring mechanism 18 is arranged above the false bottom 17, the number of the flow stabilizing plates 19 is multiple, and the multiple flow stabilizing plates 19 are evenly arranged along the circumference of the center of the impeller stirring mechanism 18, and the suction pipe 21 is arranged on the impeller stirring mechanism 1 8, the lower end of the foaming agent pipe 20 is connected to the suction pipe 21, the stator guide plate 22 is arranged at the bottom of the impeller stirring mechanism 18, the tailings pipe 16 is arranged at the bottom of the flotation tank 11, and the tailings pipe 16 is used to discharge the tailings after sorting in the flotation tank 11, the foam scraper is arranged above the first foam zone 23 and the second foam zone 25, and the foam scraper is used to collect the clean coal floated in the first foam zone 23 and the second foam zone 25 into the foam clean coal collecting tank 14.

[0044] In this embodiment, the impeller stirring mechanism 18 is the same as the stirring mechanism in the impeller stirring flotation tank in the prior art. The stirring shaft is driven by a motor, and the stirring shaft drives the stirring blades to stir. The stirring blades rotate and generate negative pressure, sucking air, collector and foaming agent from the air and foaming agent pipeline 20, and cutting the air into bubbles of appropriate size, and finally passing through the false bottom 17 and the flow stabilizer 19 to rise to the first foam zone 23 or the second foam zone 25. In the slurry-gas mixing zone, the suction pipe 21 and the stator guide plate 22 suck the slurry for mixing and circulation, so that the coarse coal particles are mineralized, collide with bubbles of appropriate size, attach to them, float to the flotation zone and the foam zone, and are finally scraped out by the foam scraper to the foam clean coal collection tank 14 to become the foam zone concentrate, and the gangue particles finally enter the tailings pipeline 16 for discharge under the action of the flow field.

[0045] like Figure 4 As shown, the wide particle size grade coal slime high recovery rate flotation system further includes a slurry mixing barrel 30, the discharge port of the slurry mixing barrel 30 is connected to the ore feeding port 12 through a pipeline, and the slurry mixing barrel 30 is used for stirring and mixing coal slime water and flotation reagents.

[0046] In this embodiment, a stirring device is provided in the slurry mixing barrel 30, which is mainly used for stirring and mixing the coal slurry water and the flotation reagent.

[0047] like Figure 4 As shown, the wide-size coal slime high-recovery flotation system further includes a centrifugal dewatering machine 31 , and the feed inlet of the centrifugal dewatering machine 31 is connected to the foam clean coal collecting tank 14 .

[0048] In this embodiment, the centrifugal dehydrator 31 is mainly used to dehydrate the clean coal collected in the foam clean coal collection tank 14. The dehydrated product is used as part of the final clean coal product. The centrifugal liquid merges with the clean coal in the overflow area of ​​the flotation device 10 and enters the flotation column 32 for further cleaning.

[0049] like Figure 4 As shown, the wide-size coal slime high-recovery flotation system further includes a flotation column 32 , and the feed inlet of the flotation column 32 is respectively connected to the filtrate outlet of the centrifugal dehydrator 31 and the fine particle overflow collection tank 13 .

[0050] In this embodiment, the flotation column 32 is used as a two-stage flotation, and the centrifugal liquid produced by dehydrating the overflow area concentrate and the foam area concentrate of the first flotation device 10 is used as a raw material, and the gangue particles are further removed to ensure that the ash content of the final clean coal product is further reduced. It is ensured that the recovery rate of the final clean coal product reaches a higher index and the ash content in the product is reduced.

[0051] like Figure 4 As shown, the wide-size coal slime high-recovery flotation system further includes a membrane filter press 33 , and the feed inlet of the membrane filter press 33 is connected to the concentrate outlet of the flotation column 32 .

[0052] In this embodiment, the membrane filter press 33 is mainly used to dehydrate the clean coal product obtained from the second-stage flotation column. The dehydrated product is introduced into the final clean coal product to obtain a complete clean coal product. The water separated by the membrane filter press 33 can be reused as circulating water to ensure a closed-loop circulation of the washing water.

[0053] like Figure 4 As shown, the wide-size coal slime high-recovery flotation system further includes a concentrator 34 , and the feed inlet of the concentrator 34 is respectively connected to the tailings outlet of the flotation column 32 and the tailings pipeline 16 .

[0054] In this embodiment, the concentrator 34 is mainly used to concentrate the tail coal of the second-stage flotation column and the tail coal of the first-stage flotation device 10 to obtain all the tail coal products. At the same time, the bottom flow water of the concentrator 34 can be used as circulating water again to ensure the closed-loop circulation of the washing water and ensure that the flotation process will not affect the local water source and other environmental factors.

[0055] The present invention also discloses a high-recovery flotation method for wide-particle-size coal slime, which is characterized in that the high-recovery flotation method for wide-particle-size coal slime is realized based on the above-mentioned high-recovery flotation system for wide-particle-size coal slime, and specifically comprises the following steps:

[0056] Step 1: Slurry preparation: coal slurry water is introduced into the slurry mixing barrel 30 at a predetermined flow rate, and flotation reagents are added into the slurry mixing barrel 30 at a predetermined ratio. The stirring mechanism in the slurry mixing barrel 30 stirs and mixes the coal slurry water and the flotation reagents at a preset speed to achieve a selective flocculation and agglomeration effect on the gangue particles in the slurry;

[0057] Step 2: Sorting by a flotation device. The slurry treated by the slurry mixing barrel 30 in step 1 is transported to the overflow area 24 in the flotation tank 11 through the ore feeding port 12 at a predetermined flow rate. Small coal particles are directly overflowed by the water flow in the flowing layer on the water surface and enter the fine-grained overflow collection tank 13 to become concentrate in the overflow area. Small gangue particles in the slurry sink from the flowing layer to the flotation area under the action of flocculation and agglomeration to participate in the flotation process. Large coal particles and gangue particles in the slurry also sink from the flowing layer to participate in subsequent flotation.

[0058] The stirring mechanism in the impeller stirring mechanism 18 rotates and generates negative pressure, sucking air, collector and foaming agent from the air and foaming agent pipeline 20, and cutting the air into bubbles of appropriate size, and finally rising to the first foam zone 23 or the second foam zone 25 through the false bottom 17 and the flow stabilizer 19, and sucking the slurry into the slurry-gas mixing zone suction pipe 21 and the stator guide plate 22 for mixing and circulation, so that the coarse coal particles complete mineralization, collide with bubbles of appropriate size, attach to and float to the flotation zone and the foam zone, and are finally scraped out by the foam scraper to the foam clean coal collection tank 14 to become the foam zone concentrate, and the gangue particles finally enter the tailings pipeline 16 for discharge under the action of the flow field.

[0059] Step 3, clean coal dehydration. The clean coal in the first flotation foam area in step 2 enters the centrifugal dehydrator 31 for dehydration. The dehydrated product is used as part of the final clean coal product. The centrifugal liquid merges with the clean coal in the overflow area of ​​the flotation device 10 and enters the flotation column 32 for concentrating.

[0060] Step 4: Second stage flotation column selection. The second stage flotation uses the centrifugal liquid produced by dehydration of the overflow area concentrate and the foam area concentrate of the first stage flotation device 10 as raw material, and further removes the gangue particles to ensure that the ash content of the final clean coal product is further reduced;

[0061] Step 5, second-stage clean coal dehydration: the clean coal product obtained by the second-stage flotation column enters the membrane filter press 33 for dehydration treatment and then passes into the final clean coal product to obtain all clean coal products. The membrane filter press 33 removes water and reuses it as circulating water;

[0062] Step 6: Dehydration of tail coal: the tail coal from the second stage flotation column and the tail coal from the first stage flotation device 10 are all concentrated in the concentrator 34 to obtain all the tail coal products. The bottom flow water from the concentrator 34 is reused as circulating water.

[0063] In step 1 of this embodiment, the slurry performs interface regulation on the surface of gangue and coal particles under the action of specific adjusting agents, dispersants, and flocculants, so that the interfacial force on the surface of gangue is expressed as attraction and flocculation occurs, and the interfacial force on the coal particles is expressed as repulsion and dispersed, thereby improving its selective flocculation effect, and controlling the rotation speed of the stirring mechanism of the stirring barrel to generate a certain fluid force field and shear rate. According to relevant research, since the floc size of coal is larger than that of quartz, when the shear rate is constant, the coal flocs will be sheared and stretched by the microscopic vortex at the same time and are more easily destroyed, while the quartz flocs are only sheared by the microscopic vortex, so the degree of destruction of the quartz flocs is relatively small. By adjusting the shear rate, the size of the microscopic vortex in the flow field can be regulated, and then the coal and quartz flocs are destroyed to different degrees, and the selective flocculation of quartz is achieved. The expected gangue selective flocculation effect is achieved through interface regulation and flow field regulation.

[0064] In step 2 described in this embodiment, the inside of the flotation tank 11 can be divided into four areas according to different functions: a foam area, an overflow area, a flotation area, and a slurry-gas mixing area. The feed port 12 is located at the inlet of the overflow area, and the fine-grained overflow collection tank 13 is located at the outlet of the overflow area, which can collect a large amount of overflow water and coal particles. There is a flowing layer at the water surface of the overflow area, and the particles are subjected to the force of water flow and gravity in the flowing layer. If the particles do not leave the flowing layer, it is believed that they will become overflow products and enter the fine-grained overflow collection tank 13. If the particles leave the flowing layer, they will sink to the flotation area and the slurry-gas mixing area to participate in subsequent flotation. The two foam areas are each provided with a foam scraper, which can scrape the foam to the foam clean coal collection tank. A flushing device can be appropriately added to the top of the two foam areas to further reduce the ash content of the clean coal in the foam area. In the slurry-gas mixing zone, negative pressure is mainly generated by the mechanical stirring mechanism, air is sucked from the suction pipe 21, and the air intake is increased or controlled by the air pump. The collector and frother required for flotation are added through the dosing pipeline, so that the slurry circulates in the stator and rotor system and the bubbles adhere to each other to complete mineralization. The large coal particles that have completed mineralization in the flotation stage rise to the foam layer to complete a flotation stage.

[0065] In this embodiment, the flotation feed is connected to the slurry mixing barrel 30, and a partition 15 is added to the foam zone of the flotation device 10 to divide the flotation foam zone into two areas, namely the overflow zone 24 and the foam zone. The foam zone includes a first foam zone 23 and a second foam zone 25. The fine-grained low-ash product enters the overflow zone 24 through the feed port 12, and flows to the fine-grained overflow collection tank 13 along the horizontal flow layer formed by the water flow in the overflow zone 24; the coarse particles sink into the impeller stirring flotation tank under the action of their own gravity for flotation, and collide with the rising bubbles. Finally, the foam formed by this part of the clean coal is scraped out in the foam zone.

[0066] Then, the concentrate in the froth zone of the flotation device 10 flows into the centrifugal dewatering machine 31, the concentrate in the overflow zone enters the flotation column 32 for selection, the tailings flow into the concentrator 34, the filtered product of the centrifugal dewatering machine 31 is discharged as the concentrate, the centrifugal liquid of the centrifugal dewatering machine 31 merges with the concentrate in the overflow zone of the flotation device 10 and flows into the flotation column 32 together, the concentrate of the flotation column 32 flows into the membrane filter press 33, the tailings of the flotation column 32 flows into the concentrator 34, the filtered material of the membrane filter press 33 is discharged as the concentrate, the filtered water of the membrane filter press 33 flows into the circulating water for subsequent sorting, the filtered product of the concentrator 34 is the tailings, and the concentrated water flows into the circulating water for subsequent sorting.

[0067] In this embodiment, the slurry processed by the slurry mixing barrel is transported to the flotation device 10 according to a certain flow rate requirement, the concentrate in the froth area of ​​the flotation device 10 enters the centrifugal dehydrator 31 for dehydration, and the concentrate in the overflow area of ​​the flotation device 10 and the centrifugal liquid enter the flotation column 32 for concentration; the flotation column 32 uses the centrifugal liquid generated by the dehydration of the overflow area concentrate and the froth area concentrate of the flotation device 10 as a raw material, and the clean coal product obtained by the flotation column 32 enters the membrane filter press 33 to complete the dehydration treatment and then passes into the final clean coal product to obtain all the clean coal products, and the water separated from the membrane filter press 33 is reused as circulating water, and the tail coal of the flotation column 32 and the tail coal of the flotation device 10 are all concentrated in the concentrator 34 to obtain all the tail coal products, and the bottom flow water of the concentrator 34 is reused as circulating water.

[0068] The present invention improves the recovery rate by more than 5% by designing a two-stage concentrating process, namely, the first stage flotation of the flotation device 10 and the second stage flotation of the flotation column 32, which can ensure that the recovery rate of the clean coal in the washed slurry is close to or even exceeds the maximum recovery rate of clean coal of different particle sizes by strictly following the particle size classification and setting different flotation processes according to different particle sizes; it can use one flotation device to float out coarse coal and fine coal at the same time under the condition of ensuring the recovery rate and ash content, reducing the additional need for particle size flotation of the existing process, and by simplifying the existing flotation process, it can save the demand for a large number of flotation machines and transportation pipelines in the design and establishment of the coal preparation plant, and the equipment required for the process has a smaller footprint than the existing process equipment, which can save more resources and bring greater economic benefits.

[0069] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A high recovery rate flotation system for wide particle size coal slime, characterized in that: The invention comprises a flotation device (10), wherein the flotation device (10) comprises a flotation tank (11), a ore feed port (12), a fine particle overflow collection tank (13), a foam clean coal collection tank (14) and a partition (15), wherein the partition (15) is arranged at the upper part of the flotation tank (11), one end of the partition (15) is connected to one side of the flotation tank (11), and the other end of the partition (15) is connected to the other side of the flotation tank (11), and the number of the partitions (15) is two, and the two partitions (15) divide the upper area of ​​the flotation tank (11) into three adjacent areas, wherein the three areas are respectively a first foam area (23), an overflow area (24) and a second foam area (25). The feed port (12) is arranged at the inlet of the overflow area (24), and the feed port (12) is connected to the overflow area (24); the fine particle overflow collection tank (13) is arranged at the outlet of the overflow area (24), and the fine particle overflow collection tank (13) is connected to the overflow area (24); the number of the foam clean coal collection tanks (14) is two, and the two foam clean coal collection tanks (14) are both arranged on the flotation tank (11), the two foam clean coal collection tanks (14) are adjacent to the fine particle overflow collection tank (13), and the two foam clean coal collection tanks (14) are respectively connected to the corresponding first foam area (23) and second foam area (25).

2. A high recovery rate flotation system for wide particle size coal slime according to claim 1, characterized in that: The flotation device (10) further comprises a false bottom (17), an impeller stirring mechanism (18), a flow stabilizing plate (19), a frother pipe (20), a material suction pipe (21), a stator guide plate (22), a tailings pipe (16) and a foam scraper, wherein the false bottom (17) is arranged at the lower part of the flotation tank (11), the impeller stirring mechanism (18) is arranged above the false bottom (17), the number of the flow stabilizing plates (19) is plural, and the plurality of flow stabilizing plates (19) are evenly arranged along the circumference of the center of the impeller stirring mechanism (18), and the material suction pipe (21) is arranged at the impeller stirring mechanism (18). 8), the lower end of the foaming agent pipe (20) is connected to the suction pipe (21), the stator guide plate (22) is arranged at the bottom of the impeller stirring mechanism (18), the tailings pipe (16) is arranged at the bottom of the flotation tank (11), and the tailings pipe (16) is used to discharge the tailings after sorting in the flotation tank (11), the foam scraper is arranged above the first foam zone (23)) and the second foam zone (25), and the foam scraper is used to collect the clean coal floated in the first foam zone (23)) and the second foam zone (25) into the foam clean coal collection tank (14).

3. A high recovery rate flotation system for wide particle size coal slime according to claim 1, characterized in that: The wide-size coal slime high-recovery flotation system also includes a slurry mixing barrel (30), the discharge port of the slurry mixing barrel (30) is connected to the ore feed port (12) through a pipeline, and the slurry mixing barrel (30) is used to stir and mix coal slime water and flotation reagents.

4. A high recovery rate flotation system for wide particle size coal slime according to claim 3, characterized in that: The wide-size coal slime high-recovery flotation system also includes a centrifugal dewatering machine (31), and the feed inlet of the centrifugal dewatering machine (31) is connected to the foam clean coal collection tank (14).

5. A high recovery rate flotation system for wide particle size coal slime according to claim 4, characterized in that: The wide-size coal slime high-recovery flotation system further comprises a flotation column (32), wherein the feed inlet of the flotation column (32) is respectively connected to the filtrate outlet of the centrifugal dehydrator (31) and the fine particle overflow collection tank (13).

6. A high recovery rate flotation system for wide particle size coal slime according to claim 5, characterized in that: The wide-size coal slime high-recovery flotation system further comprises a membrane filter press (33), wherein an inlet of the membrane filter press (33) is connected to a concentrate outlet of the flotation column (32).

7. A high recovery rate flotation system for wide particle size coal slime according to claim 6, characterized in that: The wide-size coal slime high-recovery flotation system further comprises a concentrator (34), the feed inlet of the concentrator (34) being respectively connected to the tailings outlet of the flotation column (32) and the tailings pipeline (16).

8. A method for flotation of wide-size coal slime with high recovery rate based on the flotation system for wide-size coal slime with high recovery rate as claimed in claim 7, characterized in that: The following steps are involved: Step 1, slurry preparation, coal slurry water is introduced into the slurry mixing barrel (30) at a predetermined flow rate, and a flotation agent is added into the slurry mixing barrel (30) at a predetermined ratio, and a stirring mechanism in the slurry mixing barrel (30) stirs and mixes the coal slurry water and the flotation agent at a preset speed to achieve a selective flocculation and agglomeration effect on the gangue particles in the slurry; Step 2: sorting by a first-stage flotation device, wherein the ore pulp mixed in step 1 is transported to a flotation device (10) through a ore feeding port (12), and flotation is performed by the flotation device (10). The flotation in the flotation device (10) is a first-stage flotation; Step 3, clean coal dehydration, the clean coal in the first flotation foam area in step 2 enters the centrifugal dehydrator (31) for dehydration, and the dehydrated product is used as part of the final clean coal product. The centrifugal liquid and the clean coal in the overflow area of ​​the flotation device (10) are combined and enter the flotation column (32) for fine cleaning; Step 4: Second-stage flotation column selection. The second-stage flotation uses the centrifugal liquid produced by dehydration of the overflow zone concentrate and the foam zone concentrate of the first-stage flotation device (10) as raw material, and further removes the gangue particles to ensure that the ash content of the final clean coal product is further reduced; Step 5, second-stage clean coal dehydration, the clean coal product obtained by the second-stage flotation column enters the membrane filter press (33) for dehydration treatment and then passes into the final clean coal product to obtain all the clean coal products, and the membrane filter press (33) separates the water and reuses it as circulating water; Step 6: Dehydration of tail coal: the tail coal from the second-stage flotation column and the tail coal from the first-stage flotation device (10) are all concentrated in the concentrator (34) to obtain all the tail coal products. The bottom flow water from the concentrator (34) is reused as circulating water.

9. A high recovery rate flotation method for wide particle size coal slime according to claim 8, characterized in that: The flotation reagents in step 1 include a regulator, a dispersant and a flocculant.

10. A high recovery rate flotation method for wide particle size coal slime according to claim 8, characterized in that: The specific steps of the first stage flotation device sorting in step 1 include: The ore pulp processed by the slurry mixing barrel (30) in step 1 is transported to the overflow area (24) in the flotation tank (11) through the ore feeding port (12) at a predetermined flow rate. Small coal particles are directly overflowed under the action of water flow in the water surface flowing layer and enter the fine particle overflow collecting tank (13) to become the concentrate in the overflow area. Small gangue particles in the ore pulp sink from the flowing layer to the flotation area under the action of flocculation and participate in the flotation process. Large coal particles and gangue particles in the ore pulp also sink from the flowing layer together to participate in the subsequent flotation. The stirring mechanism in the impeller stirring mechanism (18) rotates and generates negative pressure, sucking air, collector and foaming agent from the air and foaming agent pipeline (20), and cutting the air into bubbles of suitable size, and finally passing through the false bottom (17) and the flow stabilizing plate (19) to rise to the first foam area (23) or the second foam area (25), and sucking the slurry into the slurry-gas mixing area suction pipe (21) and the stator guide plate (22) for mixing and circulation, so that the coarse coal particles are mineralized, collide with bubbles of suitable size, attach to and float to the flotation area and the foam area, and are finally scraped out by the foam scraper to the foam clean coal collection tank (14) to become the foam area concentrate, and the gangue particles finally enter the tailings pipeline (16) under the action of the flow field and are discharged.

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