Sorting system and process for tailing slime

Abstract

The invention provides a separation system and process for tailing slime, relates to the technical field of mineral processing, and aims to solve the technical problem of excessive loss of valuable components in the utilization of the tailing slime. The separation system for the tailing slime comprises a first grading cyclone, a spiral separator, a second grading cyclone, first flotation equipment, second flotation equipment, concentration equipment and a first filter press, an underflow port of the first grading cyclone is in fluid connection with the spiral sorting machine, and an overflow port of the first grading cyclone is in fluid connection with the second grading cyclone; an underflow port of the second grading cyclone is in fluid connection with the first flotation equipment, and an overflow port of the second grading cyclone is in fluid connection with the second flotation equipment; an underflow port of the first flotation equipment and an underflow port of the second flotation equipment are both in fluid connection with the concentration equipment; an overflow port of the second flotation device is in fluid connection with the first filter press. The separation system can effectively improve the utilization rate of the coal slime, and energy conservation and consumption reduction of the whole production process are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of mineral processing, and in particular to a separation system and process for tailing coal slime. Background Art

[0002] my country's resource conditions of "rich in coal, little gas, and lack of oil" make coal's position as a basic energy source unshakable in the short term. How to achieve clean and efficient utilization of coal in my country is a major proposition worthy of in-depth research and innovative practice. With the gradual reduction in the number of high-quality coalfields, the gradual deterioration of geological conditions, and the development of heavy medium coal preparation technology, the coal slime content in coal is increasing.

[0003] By adopting technical means and management measures in the washing and processing links, we can recover the valuable components of coal to the maximum extent, carry out research on the comprehensive utilization and re-selection and recycling of tail coal slime, and make full use of the combustible materials in the coal resource processing link, which will help improve the competitiveness of enterprise products and promote the high-quality development of the coal industry. Summary of the invention

[0004] The object of the present invention is to provide a system and process for sorting tailings slime, so as to solve the technical problem of excessive loss of valuable components in the utilization of tailings slime.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] In a first aspect, the present invention provides a sorting system for tailings slime, comprising a first classifying cyclone, a spiral separator, a second classifying cyclone, a first flotation device, a second flotation device, a concentrating device and a first filter press;

[0007] The underflow port of the first classifying cyclone is fluidly connected to the spiral separator, and the overflow port of the first classifying cyclone is fluidly connected to the second classifying cyclone;

[0008] The underflow port of the second classifying cyclone is fluidly connected to the first flotation device, and the overflow port of the second classifying cyclone is fluidly connected to the second flotation device;

[0009] The underflow port of the first flotation device and the underflow port of the second flotation device are both fluidically connected to the concentration device;

[0010] An overflow of the second flotation device is fluidly connected to the first filter press.

[0011] According to at least one embodiment of the present invention, the first flotation device comprises a primary flotation machine and a secondary flotation machine; and / or,

[0012] The second flotation device includes a flotation column.

[0013] According to at least one embodiment of the present invention, the concentrating equipment includes a first tail coal concentrating unit and a first medium coal concentrating unit;

[0014] The underflow port of the main flotation machine is fluidly connected to the first tail coal thickening unit, and the overflow port of the main flotation machine is fluidly connected to the secondary flotation machine;

[0015] The bottom flow port of the re-selection flotation machine is fluidically connected to the first medium coal concentrator unit, and the overflow port of the re-selection flotation machine is fluidically connected to the first filter press.

[0016] According to at least one embodiment of the present invention, the overflow port of the flotation column and the overflow port of the re-flotation machine are both fluidically connected to the first filter press.

[0017] According to at least one embodiment of the present invention, the classification particle size of the tail coal slime of the first classification cyclone is 0.25 mm; and / or,

[0018] The classification particle size of the tail coal slime of the second classification cyclone is 0.075 mm.

[0019] According to at least one embodiment of the present invention, the sorting system further comprises a controller in communication with the second classifying cyclone, the controller being used to control the classification parameters of the second classifying cyclone so that the overflow product of the second classifying cyclone is mixed with a preset proportion of coal slime having a particle size greater than 0.075 mm, and the underflow product is mixed with a preset proportion of coal slime having a particle size less than 0.075 mm;

[0020] The classification parameters include at least one of a feed rate, an overflow pipe insertion depth or an underflow port diameter.

[0021] According to at least one embodiment of the present invention, the spiral separator is divided into a first gangue discharge port, a first medium coal discharge port and a first clean coal discharge port by two-stage cutters near the bottom;

[0022] The sorting system also includes three removal devices, and the first gangue discharge port, the first medium coal discharge port, and the first clean coal discharge port are respectively fluidically connected to one of the three removal devices.

[0023] According to at least one embodiment of the present invention, the removal device includes at least one of a curved screen, a high-frequency fine screen, a high-frequency screen or a first centrifuge,

[0024] The removal device is fluidically connected to the second classification cyclone to transport the undersize water or centrifuge liquid of the removal device into the second classification cyclone.

[0025] According to at least one embodiment of the present invention, the first tail coal concentrator unit includes a first stage tail coal concentrator, a second stage tail coal concentrator and a second filter press; the first medium coal concentrator unit includes a first stage medium coal concentrator and a second centrifuge;

[0026] The underflow port of the first stage middle coal concentrator is fluidically connected to the second centrifuge, and the overflow port of the first stage tail coal concentrator and the underflow port of the second centrifuge are both fluidically connected to the second stage tail coal concentrator;

[0027] The underflow port of the first-stage tail coal concentrator and the underflow port of the second-stage tail coal concentrator are both connected to the fluid of the second filter press.

[0028] According to at least one embodiment of the present invention, the sorting system further comprises a purifying concentrator, and the filtrate port of the first filter press, the filtrate port of the second filter press, and the overflow port of the second-stage tail coal concentrator are all fluidically connected to the purifying concentrator;

[0029] The overflow port of the purification concentrator is fluidically connected to the feed port of the first classification cyclone.

[0030] In a second aspect, the present invention further provides a sorting process, which uses the sorting system described in the first aspect to sort tailings slime.

[0031] Among the one or more technical solutions provided in the exemplary embodiments of the present invention, at least one of the following beneficial effects can be achieved.

[0032] The separation system for tailings slime of the exemplary embodiment of the present invention, the combination of the first classification cyclone and the spiral separator, removes coarse particles before the tailings slime is subjected to the flotation process, thereby avoiding the influence of coarse particles on the flotation effect and the flotation accuracy in the subsequent flotation process.

[0033] Furthermore, when removing coarse-grained coal slime, a spiral separator with extremely low energy consumption and no drug consumption is used to pre-sort the fine-grained coal slime, which can optimize the quality of the fine-grained coal slime that subsequently enters flotation, greatly alleviate the processing pressure of subsequent flotation equipment, and achieve reasonable configuration of the entire sorting system and energy saving and consumption reduction in the entire production process.

[0034] Before the flotation process, the second classifying cyclone is used to further subdivide the coal slime particle size, the first flotation equipment is used to sort and recover the coarser coal slime, and the second flotation equipment is used to sort and recover the finer coal slime, giving full play to the advantages of each equipment and realizing the collection of all valuable coal. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings illustrate exemplary embodiments of the present invention and together with the description serve to explain the principles of the present invention, and these drawings are included to provide a further understanding of the present invention and are incorporated in and constitute a part of this specification;

[0036] Figure 1 Schematic diagram of the structure of a sorting system according to an embodiment of the present invention.

[0037] Figure numerals: 11, first classification cyclone; 11a, coal slime bucket; 12, second classification cyclone; 12a, flotation bucket; 20, spiral separator; 31a, curved screen; 31b, high-frequency screen; 31c, high-frequency fine screen; 41, first centrifuge; 42, second centrifuge; 51, flotation column; 52a, primary flotation machine; 52b, secondary flotation machine; 61, first filter press; 62, second filter press; 71, first stage tail coal concentrator; 72, second stage tail coal concentrator; 73, first stage middle coal concentrator; 74, purification concentrator. DETAILED DESCRIPTION

[0038] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0039] Figure 1 Schematic diagram of the structure of the sorting system according to the embodiment of the present invention. Figure 1 As shown, the sorting system for tailings slime provided by the exemplary embodiment of the present invention comprises a first classifying cyclone 11, a spiral separator 20, a second classifying cyclone 12, a first flotation device, a second flotation device, a thickening device and a first filter press 61; the underflow port of the first classifying cyclone 11 is fluidly connected to the spiral separator 20, and the overflow port of the first classifying cyclone 11 is fluidly connected to the second classifying cyclone 12; the underflow port of the second classifying cyclone 12 is fluidly connected to the first flotation device, and the overflow port of the second classifying cyclone 12 is fluidly connected to the second flotation device; the underflow port of the first flotation device and the underflow port of the second flotation device are both fluidly connected to the thickening device; the overflow port of the second flotation device is fluidly connected to the first filter press 61.

[0040] Exemplarily, the first flotation device includes one or both of a primary flotation machine 52 a and a secondary flotation machine 52 b ; the following description will be given taking two flotation machines as an example; the second flotation device includes a flotation column 51 .

[0041] For example, the classification particle size of the tail coal slime of the first classification cyclone 11 is 0.25mm; the classification particle size of the tail coal slime of the first classification cyclone 11 is 0.075mm. For example, the first classification cyclone 11 classifies the tail coal slime into fine particles less than or equal to 0.25mm and coarse particles greater than 0.25mm; the second classification cyclone 12 classifies the fine particles into very fine particles less than or equal to 0.075mm and finer particles greater than 0.075mm and less than 0.25mm.

[0042] It should be noted that the above-mentioned classification particle size is only an example and is not a limitation on the classification particle size of the first classification cyclone 11 and the second classification cyclone 12 in the present invention, and can be adjusted according to actual needs.

[0043] In practical applications, the tail coal slime with insufficient recovery produced by the coking coal preparation plant, or the coal slime products produced by the thermal coal preparation plant without fine coal sorting link, are transported and unloaded into the coal slime stirring tank for preliminary slurry treatment. A slurry pump is installed under the coal slime tank to pump the pre-slurried coal slime to the coal slime barrel 11a for buffering, and circulating water of the sorting system is added to the coal slime barrel 11a to a suitable coal slime concentration, for example, 15% to 30%.

[0044] The coal slime enters the first classification cyclone 11 and is classified into coarse particles and fine particles. The fine particle coal slime is collected in the flotation material barrel 12a, and then enters the second classification cyclone 12, and is further classified into ultrafine particles and relatively fine particles. The ultrafine particle coal slime enters the slurry mixing barrel for slurry mixing treatment, for example, adding a suitable proportion of clean water to adjust the coal slime concentration to 40g / L~100g / L; according to the actual coal slime flotation reagent, the flotation reagents such as the adjusting agent, the collecting agent, the frother, etc. are added into the mixing barrel to complete the pretreatment of the coal slime before flotation.

[0045] Before flotation, the finer particles of coal slime are also put into the slurry mixing barrel for slurry mixing treatment, such as adding a suitable proportion of clean water to adjust the coal slime concentration to 30g / L~80g / L; according to the actual coal slime flotation reagents, adjusters, collectors, frothers and other flotation reagents are added into the mixing barrel to complete the pretreatment of the slurry before flotation.

[0046] It should be noted that, according to the actual flotation process, the above-mentioned flotation reagents can be added into the flotation equipment to achieve the expected flotation effect.

[0047] Furthermore, the pretreated ultrafine coal slime enters the flotation column 51 for flotation, wherein the flotation column 51 may be a cyclone microbubble flotation column, the underflow product of the flotation column 51 is dehydrated by a concentration device as the tail coal product T2, and the overflow product of the flotation column 51 is dehydrated by a first filter press 61 as the clean coal product C1.

[0048] Furthermore, the pretreated finer particle coal slime enters the main flotation machine 52a and the re-selection flotation machine 52b for two-stage flotation. Specifically, the overflow product of the main flotation machine 52a is adjusted to an appropriate concentration and then fed into the re-selection flotation machine 52b for secondary flotation. The underflow product of the main flotation machine 52a is dehydrated by a thickening device and used as the tail coal product T2, and the underflow product of the re-selection flotation machine 52b is dehydrated by a thickening device and used as the medium coal product M2.

[0049] Furthermore, the overflow product of the flotation machine 52b and the overflow product of the flotation column 51 are simultaneously fed into the first filter press 61 for dehydration treatment to obtain the final clean coal product C1.

[0050] Exemplarily, the first filter press 61 is a fast-opening filter press. Since the particle size of the overflow product of the reselection flotation machine 52b (greater than 0.075mm and less than 0.25mm) is different from the particle size of the overflow product of the flotation column 51 (less than or equal to 0.075mm), the two streams of clean coal products with different particle sizes are fed into the first filter press 61 for dehydration together, which can avoid the feed particle size being too small during the filtration, the filter cake pore size, pore area and porosity being reduced, and the pore ratio of small pores being increased, resulting in too slow a filtration speed; it also avoids the particles being too large due to the feed particle size being too large, which easily clogs the filter press feed hose, or easily gathers in the filter plate boss area and damages the filter cloth.

[0051] In some embodiments, the position near the bottom of the spiral classifier 20 is divided into a first gangue discharge port, a first medium coal discharge port and a first clean coal discharge port by two-stage cutters; the sorting system also includes three removal devices, and the first gangue discharge port, the first medium coal discharge port and the first clean coal discharge port are fluidically connected to one of the three removal devices respectively.

[0052] The working principle of the spiral separator 20 mainly relies on the centrifugal force on the materials in the separation tank. The heavier materials will move inwards towards the spiral shaft, while the lighter materials will move towards the outside of the separation tank. After the materials are separated in the separation tank, they are separated from different discharge devices according to their size and weight to form a separated material flow.

[0053] The spiral separator 20 is provided with two-stage cutters to separate the coal slime flow into a clean coal flow, a medium coal flow and a gangue flow, and then passes through corresponding removal equipment to separate the coarse coal slime.

[0054] For example, the material flowing out from the first gangue discharge port of the spiral separator 20 passes through the curved screen 31a and the high-frequency screen 31b to remove fine particles of coal slime and moisture, thereby forming a gangue product T1.

[0055] The material flowing out from the first medium coal discharge port of the spiral separator 20 passes through the curved screen 31a and the high-frequency screen 31b to remove fine particles of coal slime and moisture, thereby forming a medium coal product M1.

[0056] The material flowing out from the first clean coal discharge port of the spiral separator 20 passes through the high-frequency fine screen 31c and the first centrifuge 41 to remove fine particle coal slime and moisture to form a clean coal product C1, wherein the high-frequency fine screen 31c can be a laminated high-frequency fine screen.

[0057] Furthermore, the under-screen water, centrifugal liquid, etc. after being processed by the curved screen 31a, high-frequency screen 31b, high-frequency fine screen 31c and the first centrifuge 41 still contain a large amount of fine-particle coal slime. Therefore, the under-screen water, centrifugal liquid and overflow product of the first classification cyclone 11 all enter the flotation material bucket 12a to be flotated by the second classification cyclone 12 and the corresponding flotation equipment. Based on this, the sorting system of the exemplary embodiment of the present invention can achieve strict control of coal slime particle size before the flotation process to avoid the influence of coarse-particle coal slime on the flotation effect and flotation accuracy.

[0058] In some embodiments, Figure 1 As shown, the concentrating equipment in the sorting system of the exemplary embodiment of the present invention includes a first tail coal concentrating unit and a first middle coal concentrating unit; the bottom flow port of the main selection flotation machine 52a is fluidly connected to the first tail coal concentrating unit, and the overflow port of the main selection flotation machine 52a is fluidly connected to the re-selection flotation machine 52b; the bottom flow port of the re-selection flotation machine 52b is fluidly connected to the first middle coal concentrating unit, and the overflow port of the re-selection flotation machine 52b is fluidly connected to the first filter press 61.

[0059] Exemplarily, the first tail coal concentrator unit includes a first-stage tail coal concentrator 71, a second-stage tail coal concentrator 72 and a second filter press 62; the first medium coal concentrator unit includes a first-stage medium coal concentrator 73 and a second centrifuge 42; the bottom flow port of the first-stage medium coal concentrator 73 is fluidly connected to the second centrifuge 42, and the overflow port of the first-stage tail coal concentrator 71 and the bottom flow port of the second centrifuge 42 are both fluidly connected to the second-stage tail coal concentrator 72; the bottom flow port of the first-stage tail coal concentrator 71 and the bottom flow port of the second centrifuge 42 are both fluidly connected to the second filter press 62.

[0060] Exemplarily, the sorting system of the exemplary embodiment of the present invention also includes a purification concentrator 74, and the filtrate port of the first filter press 61, the filtrate port of the second filter press 62, and the overflow port of the second-stage tail coal concentrator 72 are all fluidly connected to the purification concentrator 74; the overflow port of the purification concentrator 74 is fluidly connected to the feed port of the first grading cyclone 11.

[0061] In actual applications, the underflow of the main flotation machine 52a and the underflow of the flotation column 51 are both concentrated and precipitated through the first-stage tailings concentrator 71, and the overflow of the first-stage tailings concentrator 71 is fed into the second-stage tailings concentrator 72; the underflow of the first-stage tailings concentrator 71 and the underflow of the second-stage tailings concentrator 72 are dehydrated through the second filter press 62 to form the tailings product T2.

[0062] The bottom flow of the flotation machine 52b is concentrated and precipitated by the first stage medium coal concentrator 73, and the bottom flow of the first stage medium coal concentrator 73 is dehydrated by the second centrifuge 42 to form the medium coal product M2. The centrifuge liquid of the second centrifuge 42 flows to the second stage tail coal concentrator 72 for processing.

[0063] The filtrate of the first filter press 61, the filtrate of the second filter press 62, and the overflow of the second-stage tail coal concentrator 72 enter the purification concentrator 74 together, which can be a purification concentrator tank for clarification and purification. The overflow can be used as circulating water and can be connected to the coal slime barrel 11a, thereby forming a closed-loop treatment of water circulation. Based on this, compared with the prior art, many coal preparation plants have excessively simplified the coal slime water treatment process, resulting in serious excess of solid content and residual reagents in clarified overflow water, which then accumulates and circulates in the production water of the coal preparation plant, causing the production conditions to deteriorate, the accuracy of the grading and sorting process to be seriously reduced, and the quality of the products produced to continue to decline.

[0064] In the sorting system of the exemplary embodiment of the present invention, the combination of the first stage tail coal concentrator 71, the second stage tail coal concentrator 72, the first stage medium coal concentrator 73, the second centrifuge 42, the second filter press 62 and the purification concentrator 74 realizes the efficient treatment of the coal slime water generated in the flotation link through step-by-step concentration and purification, and realizes the reasonable classification of coal slime and tail coal slime products in the coal slime water treatment link. At the same time, the primary closed-loop recycling of the production water of the coal preparation plant is realized, ensuring the long-term efficient and qualified production of the coal preparation plant.

[0065] In some embodiments, the sorting system of the exemplary embodiment of the present invention further includes a controller communicatively connected to the second classifying cyclone 12, and the controller is used to control the grading parameters of the second classifying cyclone 12 so that the overflow product of the second classifying cyclone 12 is mixed with a preset proportion of coal slime with a particle size greater than 0.075 mm, and the underflow product is mixed with a preset proportion of coal slime with a particle size less than 0.075 mm; the grading parameters include at least one of the feed rate, the overflow pipe insertion depth or the underflow port diameter.

[0066] In the flotation process, the flotation machine (primary flotation machine 52a, secondary flotation machine 52b) is used to float the finer particle coal slime, and the flotation column 51 is used to float the ultra-fine particle coal slime. The applicant has found that the flotation of coal slime with a single particle size and a narrow particle size range not only has a slow flotation rate but also a low recovery rate of the flotation combustibles. The flotation effect can be improved by adding a certain proportion (20%) of ultra-fine particles to the finer particles processed by the flotation machine and a certain proportion (20%) of finer particles to the ultra-fine particles processed by the flotation column 51.

[0067] In order to achieve the purpose of improving the flotation effect, the second classifying cyclone 12 is different from the first classifying cyclone 11. By controlling the feed pressure, overflow pipe insertion depth, bottom flow port diameter and other parameters of the second classifying cyclone 12 through a controller, a certain proportion of ultrafine particles can be mixed into finer particles, and a certain proportion of finer particles can be mixed into ultrafine particles.

[0068] For example, when the ratio of the overflow pipe diameter of the second classifying cyclone 12 to the cylinder diameter of the second classifying cyclone 12 is 0.3-0.6, by increasing the diameter of the overflow pipe mouth; reducing the insertion depth of the overflow pipe within the range of overflow pipe insertion depth / cyclone cylinder diameter of 0.5-1.5; reducing the diameter of the underflow pipe mouth within the range of underflow pipe diameter / cyclone cylinder diameter of 0.05-0.15; and reducing the feed pressure (feed speed), etc., a certain proportion, for example 20%, of finer particles (greater than 0.075 mm) can be mixed into the ultrafine particles (less than or equal to 0.075 mm).

[0069] In another optional embodiment, the sorting system of the exemplary embodiment of the present invention further includes a control device, a first barrel, a second barrel, and two guide pipes, each guide pipe is provided with a control valve that is communicatively connected to the control device, wherein the top of the first barrel is fluidly connected to the bottom flow port of the second classification cyclone 12, the bottom of the first barrel is fluidly connected to the feed port of the main flotation machine 52a, and is fluidly connected to the feed port of the flotation column 51 through one of the two guide pipes; the top of the second barrel is fluidly connected to the overflow port of the second classification cyclone 12, the bottom of the second barrel is fluidly connected to the feed port of the flotation column 51, and is fluidly connected to the feed port of the main flotation machine 52a through the other of the two guide pipes. The control device can be a computer, PLC, etc.

[0070] By controlling the flow rate of the corresponding diversion through the control equipment, it is possible to mix a certain proportion of ultrafine particles into finer particles, and vice versa, thereby giving full play to the respective advantages of the flotation machine process and the flotation column process.

[0071] In the graded flotation process, the ultrafine particles in the flotation column 51 are mixed with 20% of the finer particle coal slime, which can provide carriers for the ultrafine particles, increase the collision probability between the flotation bubbles and the particles, and improve the flotation effect of the ultrafine particle coal slime, so as to fully reflect the advantages of the cyclone microbubble flotation column 51 in the flotation of ultrafine particle coal slime. In the flotation machine (primary flotation machine 52a, secondary flotation machine 52b), such as the mechanical stirring flotation machine, the finer particles are mixed with 20% of the ultrafine particle coal slime, which can promote the adhesion probability of the finer coal slime and the bubble after the collision, and form stable armored bubbles of finer particles, avoid the desorption of finer particle clean coal caused by the high turbulent flow field inside the mechanical stirring flotation machine, and significantly improve the flotation effect of finer particle coal slime.

[0072] Through the coordinated cooperation of the above-mentioned second classification cyclone, cyclone microbubble flotation column, and mechanical stirring flotation machine (primary flotation machine, secondary flotation machine), the advantages of each equipment can be fully utilized to achieve the collection of valuable coal and avoid the loss of valuable components.

[0073] The exemplary embodiment of the present invention further provides a sorting process, which uses the sorting system of the above embodiment to sort tailings slime.

[0074] The technical advantages of the above-mentioned sorting process over the prior art are the same as the advantages of the above-mentioned sorting system, which will not be repeated here.

[0075] It should be understood by those skilled in the art that the above embodiments are only for the purpose of clearly illustrating the present invention, and are not intended to limit the scope of the present invention. For those skilled in the art, other changes or modifications may be made based on the above disclosure, and these changes or modifications are still within the scope of the present invention.

Claims

1. A sorting system for tailings slime, characterized in that: It includes a first classifying cyclone, a spiral separator, a second classifying cyclone, a first flotation device, a second flotation device, a concentration device and a first filter press; The underflow port of the first classifying cyclone is fluidly connected to the spiral separator, and the overflow port of the first classifying cyclone is fluidly connected to the second classifying cyclone; The underflow port of the second classifying cyclone is fluidly connected to the first flotation device, and the overflow port of the second classifying cyclone is fluidly connected to the second flotation device; The underflow port of the first flotation device and the underflow port of the second flotation device are both fluidically connected to the concentration device; An overflow of the second flotation device is fluidly connected to the first filter press.

2. The sorting system according to claim 1, characterized in that: The first flotation equipment includes a primary flotation machine and a secondary flotation machine; and / or, The second flotation device includes a flotation column.

3. The sorting system according to claim 2, characterized in that: The concentration equipment includes a first tail coal concentration unit and a first medium coal concentration unit; The underflow port of the main flotation machine is fluidly connected to the first tail coal thickening unit, and the overflow port of the main flotation machine is fluidly connected to the secondary flotation machine; The bottom flow port of the re-selection flotation machine is fluidically connected to the first medium coal concentrator unit, and the overflow port of the re-selection flotation machine is fluidically connected to the first filter press.

4. The sorting system according to claim 3, characterized in that: The classification particle size of the tail coal slime of the first classification cyclone is 0.25 mm.

5. The sorting system according to claim 3, characterized in that: The classification particle size of the tail coal slime of the second classification cyclone is 0.075 mm.

6. The sorting system according to claim 3, characterized in that: The position near the bottom of the spiral separator is divided into a first gangue discharge port, a first medium coal discharge port and a first clean coal discharge port by two-stage cutters; The sorting system also includes three removal devices, and the first gangue discharge port, the first medium coal discharge port, and the first clean coal discharge port are respectively fluidically connected to one of the three removal devices.

7. The sorting system according to claim 6, characterized in that: The removal device includes at least one of a curved screen, a high-frequency fine screen, a high-frequency screen or a first centrifuge, The removal device is fluidically connected to the second classification cyclone to transport the undersize water or centrifuge liquid of the removal device into the second classification cyclone.

8. The sorting system according to claim 6, characterized in that: The first tail coal concentrator unit includes a first stage tail coal concentrator, a second stage tail coal concentrator and a second filter press; the first medium coal concentrator unit includes a first stage medium coal concentrator and a second centrifuge; The underflow port of the first stage middle coal concentrator is fluidically connected to the second centrifuge, and the overflow port of the first stage tail coal concentrator and the underflow port of the second centrifuge are both fluidically connected to the second stage tail coal concentrator; The underflow port of the first-stage tail coal concentrator and the underflow port of the second-stage tail coal concentrator are both connected to the fluid of the second filter press.

9. The sorting system according to claim 8, characterized in that: The sorting system further comprises a purification concentrator, wherein the filtrate port of the first filter press, the filtrate port of the second filter press, and the overflow port of the second-stage tail coal concentrator are all fluidically connected to the purification concentrator; The overflow port of the purification concentrator is fluidically connected to the feed port of the first classification cyclone.

10. A sorting process, characterized in that: The tailings slime is sorted using the sorting system described in any one of claims 1 to 9.

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