Coal slime flotation system and coal slime flotation process

Abstract

The application discloses a slime flotation system and a slime flotation process, wherein the clean coal magnetic tail is classified into coarse slime and fine slime through a grading device, the coarse slime is directly sent to a first centrifuge for dewatering treatment to directly obtain low-ash clean coal, the fine slime is sent to a roughing flotation machine and a primary cleaning flotation machine and then enters the first centrifuge for dewatering treatment to obtain low-ash clean coal, centrifugal liquid after dewatering of the first centrifuge is sent to a secondary cleaning flotation machine for secondary flotation, and the clean coal after the secondary flotation is sent to a clean coal filter press for dewatering treatment to obtain low-ash clean coal. Thus, the workload of the roughing flotation machine and the primary cleaning flotation machine is reduced, the primary flotation time is shortened, and the loss of qualified coarse clean slime is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of coal slime flotation, in particular to a coal slime flotation system and a coal slime flotation process. BACKGROUND

[0002] At present, the gangue content of coal gradually increases, the sliming phenomenon intensifies, and the high-ash fine slime content in the flotation feed shows an upward trend. The high-ash fine slime is mainly composed of two parts: one part is fine clay minerals, and the other part is micro-fine minerals produced after argillaceous minerals sliming, including clay minerals, oxides, etc. In the flotation process, a large amount of reagents are adsorbed on the surface of high-ash fine slime, and at the same time, the surface of foam and coarse particles is occupied, which increases the slime content of clean coal and intensifies the coarse running of flotation tailings, is the main reason for the over-standard of clean coal ash, the low ash content of flotation tailings, and the low added value of coal slime, causing great economic losses to the coal preparation plant.

[0003] In the prior art, during the coal slime flotation, all the clean coal magnetic tailings are subjected to flotation by the cleaning flotation machine, the flotation feed amount is large, the working load of the cleaning flotation machine is large, the flotation time is long, and in the flotation process, coarse clean slime loss may also be caused. SUMMARY

[0004] The present application aims to overcome the shortcomings of the prior art, and provides a coal slime flotation system and a coal slime flotation process, which reduces the working load of the roughing flotation machine and the primary cleaning flotation machine, shortens the primary flotation time, and reduces the loss of qualified coarse clean slime.

[0005] The technical scheme of the present application provides a coal slime flotation system, which comprises a clean coal magnetic tail treatment system, a medium coal magnetic tail treatment system, and a tailings treatment system.

[0006] The clean coal magnetic tail treatment system comprises a classification device, a pre-treater, a roughing flotation machine, a primary cleaning flotation machine, a first centrifuge, a secondary cleaning flotation machine, and a clean coal filter press, which are connected in sequence.

[0007] The medium coal magnetic tail treatment system comprises a first thickener, a second centrifuge, a second thickener, and a medium coal filter press, which are connected in sequence.

[0008] The tailings treatment system comprises a third thickener and a tail coal filter press, which are connected in sequence.

[0009] The coarse slime output port of the classification device is connected with the first centrifuge, and the fine slime output port of the classification device is connected with the pre-treater.

[0010] The clean coal output port of the roughing flotation machine is connected with the primary cleaning flotation machine, the middlings output port of the roughing flotation machine is connected with the second centrifuge, and the tailings output port of the roughing flotation machine is connected with the third thickener.

[0011] The concentrate output port of the primary cleaning flotation machine is connected with the first centrifuge, and the tailing output port of the primary cleaning flotation machine is connected with the first thickener;

[0012] The concentrate output port of the secondary cleaning flotation machine is connected with the clean coal filter press, and the tailing output port of the secondary cleaning flotation machine is connected with the first thickener.

[0013] In one of the optional technical solutions, the first centrifuge and the second centrifuge are both sedimentation filtration type centrifuges.

[0014] In one of the optional technical solutions, the classification particle size of the first centrifuge and the second centrifuge is between 0.04mm-0.05mm.

[0015] In one of the optional technical solutions, the classification equipment includes an arc-shaped screen, and the screen gap or screen hole of the arc-shaped screen is between 0.15mm-0.2mm.

[0016] The technical solution of the present application also provides a slime flotation process, which adopts the slime flotation system according to any one of the preceding technical solutions.

[0017] The slime flotation system includes the following steps:

[0018] S1: treating the clean coal magnetic tail by a clean coal magnetic tail treatment system to obtain low-ash clean coal;

[0019] S2: treating the medium-ash coal slime by a medium-ash coal slime treatment system, and treating the middlings and tailings generated by the clean coal magnetic tail treatment system by the medium-ash coal slime treatment system to obtain the medium-ash coal slime;

[0020] S3: treating the high-ash tailings generated by the clean coal magnetic tail treatment system by a tailings treatment system to obtain high-ash coal slime;

[0021] In step S1, the following steps are included:

[0022] S11: the clean coal magnetic tail enters the classification equipment to remove coarse coal, and the coarse coal output from the coarse coal slime output port of the classification equipment is conveyed to the first centrifuge, and the fine coal slime output from the fine coal slime output port of the classification equipment is conveyed to the pre-treater;

[0023] S12: the coal slime treated by the pre-treater enters the roughing flotation machine;

[0024] S13: the high-ash tailings output from the tailings output port of the roughing flotation machine are conveyed to the third thickener;

[0025] The middlings output from the middlings output port of the roughing flotation machine are conveyed to the second centrifuge;

[0026] The concentrate output from the concentrate output port of the roughing flotation machine is conveyed to the primary cleaning flotation machine;

[0027] S14: The concentrate output from the concentrate outlet of the primary cleaning flotation machine is conveyed to the first centrifuge, and the tailings output from the tailings outlet of the primary cleaning flotation machine are conveyed to the first thickener.

[0028] S15: The first centrifuge dewaters to obtain low-ash clean coal, and the centrifugal liquid produced by the first centrifuge is sent to the secondary cleaning flotation machine;

[0029] S16: The concentrate output from the secondary flotation machine is transported to the clean coal filter press, and the tailings output from the secondary flotation machine are transported to the first thickener.

[0030] S17: Low-ash clean coal is obtained by dewatering clean coal using a coal filter press.

[0031] In one of the alternative technical solutions, in step S17: the overflow generated during the dewatering of the clean coal filter press is used as circulating water.

[0032] In one of the optional technical solutions, step S2 includes:

[0033] S21: Tailings from the primary flotation unit, tailings from the secondary flotation unit, and middlings magnetic tailings enter the first thickener;

[0034] S22: The underflow from the first thickener and the middlings from the roughing flotation machine are respectively conveyed to the second centrifuge;

[0035] S23: The second centrifuge dewaters to obtain medium-ash coal slime, and the centrifuged liquid from the second centrifuge is sent to the second thickener;

[0036] S24: The underflow from the second thickener is conveyed to the medium-coal filter press;

[0037] S25: Medium-ash coal slime is obtained by dewatering and recovering coal slime using a coal filter press.

[0038] In one of the alternative technical solutions, in step S25: the overflow generated during the dewatering of the coal filter press is used as circulating water.

[0039] In one of the optional technical solutions, step S3 includes:

[0040] S31: The high-ash tailings from the roughing flotation machine are output to the third thickener;

[0041] S32: The underflow from the third thickener is pumped into the tailings filter press by a slurry pump;

[0042] S33: High-ash coal slime is obtained by dewatering and recovering tailings using a filter press.

[0043] In one of the alternative technical solutions, in step S33: the overflow generated during the dewatering of the tailings filter press is used as circulating water.

[0044] The above technical solution has the following beneficial effects:

[0045] The coal slime flotation system and process provided by this invention classify clean coal into coarse and fine coal slime using a classifying device. The coarse coal slime is directly dewatered in a first centrifuge to obtain low-ash clean coal. The fine coal slime passes through a roughing flotation machine and a primary cleaning flotation machine before entering the first centrifuge for dewatering to obtain low-ash clean coal. The dewatered liquid from the first centrifuge then enters a secondary cleaning flotation machine for secondary flotation. The concentrate after secondary flotation is then dewatered in a clean coal filter press to obtain low-ash clean coal. This reduces the workload of the roughing and primary cleaning flotation machines, shortens the primary flotation time, and minimizes the loss of qualified coarse and clean coal slime.

[0046] The coal slime flotation system and process provided by this invention include a rougher flotation machine that outputs middlings to the second centrifuge of the middlings magnetic tailings treatment system, and a primary and secondary cleaning flotation machine that outputs tailings to the first thickener, where the middlings magnetic tailings treatment system recovers and obtains mid-ash coal slime.

[0047] The coal slime flotation system and process provided by this invention allow the tailings flotated by the rougher flotation machine to be output to the third thickener, where the tailings are recovered by the tailings treatment system to obtain high-ash coal slime.

[0048] The coal slime flotation system and process provided by this invention not only improve the yield of clean coal from flotation, but also classify and process the coal slime for subsequent processing and management. Attached Figure Description

[0049] The disclosure of this invention will become more readily understood by referring to the accompanying drawings. It should be understood that these drawings are for illustrative purposes only and are not intended to limit the scope of protection of this invention. In the drawings:

[0050] Figure 1 This is a schematic diagram of a coal slime flotation system provided in an embodiment of the present invention. Detailed Implementation

[0051] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings. Identical components are indicated by the same reference numerals. It should be noted that the terms "front," "rear," "left," "right," "up," and "down" used in the following description refer to directions in the accompanying drawings, while the terms "inner" and "outer" refer to directions toward or away from the geometric center of a specific component, respectively.

[0052] like Figure 1 As shown, an embodiment of the present invention provides a coal slime flotation system, including a clean coal magnetic tailings treatment system 1, a middlings magnetic tailings treatment system 2, and a tailings treatment system 3.

[0053] The clean coal magnetic tail processing system 1 comprises a grading device 11, a pre-treater 12, a roughing flotation machine 13, a primary cleaning flotation machine 14, a first centrifuge 15, a secondary cleaning flotation machine 16 and a clean coal filter press 17 connected in sequence.

[0054] The middling coal magnetic tail processing system 2 comprises a first thickener 21, a second centrifuge 22, a second thickener 23 and a middling coal filter press 24 connected in sequence.

[0055] The tailing processing system 3 comprises a third thickener 31 and a tail coal filter press 32 connected in sequence.

[0056] The coarse slime output port 111 of the grading device 11 is connected with the first centrifuge 15, and the fine slime output port 112 of the grading device 11 is connected with the pre-treater 12.

[0057] The concentrate output port 131 of the roughing flotation machine 13 is connected with the primary cleaning flotation machine 14, the middling output port 132 of the roughing flotation machine 13 is connected with the second centrifuge 22, and the tailing output port 133 of the roughing flotation machine 13 is connected with the third thickener 31.

[0058] The concentrate output port 141 of the primary cleaning flotation machine 14 is connected with the first centrifuge 15, and the tailing output port 142 of the primary cleaning flotation machine 14 is connected with the first thickener 21.

[0059] The concentrate output port 161 of the secondary cleaning flotation machine 16 is connected with the clean coal filter press 17, and the tailing output port 162 of the secondary cleaning flotation machine 16 is connected with the first thickener 21.

[0060] The coal slime flotation system provided by the application is used for floating coking coal slime, and comprises the clean coal magnetic tail processing system 1, the middling coal magnetic tail processing system 2 and the tailing processing system 3.

[0061] Coal is divided into:

[0062] Raw coal - coal that has not been sorted.

[0063] Middling coal - a 2nd grade product that has been sorted.

[0064] Washed coal - coal that has been sorted.

[0065] Clean coal - the final coal that has been sorted according to customer needs.

[0066] The tailings produced by the clean coal magnetic separator are called clean coal magnetic tailings, and the tailings produced by the middling coal magnetic separator are called middling coal magnetic tailings.

[0067] The clean coal magnetic tailings are processed by the clean coal magnetic tail processing system 1 to obtain low-ash clean coal.

[0068] The middlings and tailings produced by the middlings magnetic tail treatment system 2 and the clean coal magnetic tail treatment system 1 are treated to obtain medium-ash slime.

[0069] The high-ash tailings produced by the clean coal magnetic tail treatment system 1 are treated by the tailings treatment system 3 to obtain high-ash slime.

[0070] The classification device 11 is used for screening and classifying the clean coal magnetic tail to separate coarse slime and fine slime. The coarse slime has little ash content and has already met the requirements, and can be directly recovered by the first centrifugal machine 15 to produce low-ash clean coal. The fine slime still needs to be treated by at least two times of flotation. The coarse slime is directly output to the first centrifugal machine 15 through the coarse slime output port 111 of the classification device 11.

[0071] The fine slime is output to the pretreater 12 through the fine slime output port 112 of the classification device 11. After being diluted by water, the fine slime is mixed with flotation reagents in the pretreater 12, and then output to the roughing flotation machine 13 in the tailings treatment system 3.

[0072] The roughing flotation machine 13 includes five flotation chambers, the concentrate is floated out in the first to third chambers, the flotation reagents are added again in the fourth chamber, and the middlings are floated out in the fourth to fifth chambers.

[0073] The high-ash tailings floated out by the roughing flotation machine 13 are output to the third thickener 31 through the tailings output port 133. The ash content of the high-ash tailings is as high as 80% or more. The underflow of the third thickener 31 is pumped into the tailings filter press 32 by a slurry pump, and the high-ash slime is obtained by dehydration recovery of the tailings filter press 32. The overflow produced by the tailings filter press 32 during dehydration is used as circulating water. The ash content of the high-ash slime is high, and the calorific value is almost zero, which can be directly discarded.

[0074] The middlings floated out by the roughing flotation machine 13 are output to the second centrifugal machine 22 through the middlings output port 132. The ash content of the middlings is about 20%-40%. The middlings floated out by the roughing flotation machine 13 are treated by the middlings magnetic tail treatment system 2, and finally the medium-ash slime is obtained.

[0075] The concentrate floated out by the roughing flotation machine 13 is output to the primary cleaning flotation machine 14 through the concentrate output port 131 for re-flotation.

[0076] The concentrate floated out by the roughing flotation machine 13 is diluted and then enters the primary cleaning flotation machine 14, from which the high-ash fine slime is removed, and the concentrate and tailings are re-fl oated or separated.

[0077] The tailings selected by the primary cleaning flotation machine 14 are output to the first thickener 21 through the tailings output port 142, and finally the medium-ash slime is obtained by the middlings magnetic tail treatment system 2.

[0078] The concentrate floated by the primary cleaning flotation machine 14 is output to the first centrifuge 15 through a concentrate output port 141.

[0079] Specifically, the concentrate floated by the primary cleaning flotation machine 14 is fed into the first centrifuge 15 together with the coarse slime screened by the classification device 11 for dewatering and recovery, so as to obtain low-ash clean coal.

[0080] The first centrifuge 15 can be a sedimentation filtration type centrifuge.

[0081] The first centrifuge 15 can also perform classification according to particle size while dewatering, and the classification particle size is between 0.04 mm and 0.05 mm, i.e. about 0.045 mm. Therefore, the fine particle centrifugal liquid can be fed into the secondary cleaning flotation machine 16 for re-flotation, so as to improve the selectivity of fine particle slime and ensure that the fine particle clean coal meets the ash content requirement.

[0082] The concentrate floated by the secondary cleaning flotation machine 16 is output to the clean coal filter press 17 through a concentrate output port 161, and the clean coal filter press 17 dewatering obtains low-ash clean coal. The overflow produced by the clean coal filter press 17 during dewatering can be used as circulating water.

[0083] The tailings screened by the secondary cleaning flotation machine 16 are output to the first thickener 21 through a tailings output port 162. The tailings are processed by the medium-ash coal slime processing system 2, and finally medium-ash coal slime is obtained.

[0084] The tailings of the primary cleaning flotation machine 14 and the secondary cleaning flotation machine 16 are both cleaning tailings, and this part of material is high-ash fine slime and part of medium coal removed, and the ash content is generally between 30% and 60%. This part of coal slime has recovery value, and therefore the tailings are input to the first thickener 21 together with the medium-ash coal tailings. The underflow of the first thickener 21 and the middlings screened by the roughing flotation machine 13 are output to the second centrifuge 22 for dewatering and recovery, so as to obtain medium-ash coal slime. The second centrifuge 22 can be a sedimentation filtration type centrifuge.

[0085] The second centrifuge 22 can also perform classification according to particle size while dewatering, and the classification particle size is between 0.04 mm and 0.05 mm, i.e. about 0.045 mm. Therefore, the fine particle centrifugal liquid can be fed into the second thickener 23 for dewatering. The underflow of the second thickener 23 is fed into the medium coal filter press 24 for dewatering and recovery, so as to obtain medium-ash coal slime. The overflow produced by the medium coal filter press 24 during dewatering can be used as circulating water.

[0086] Thus, the coal slime flotation system provided by the present application classifies the clean coal magnetic tail into coarse slime and fine slime through the grading device 11, the coarse slime is directly sent to the first centrifuge 15 for dewatering treatment to directly obtain low-ash clean coal, the fine slime is sent to the roughing flotation machine 13 and the primary cleaning flotation machine 14 and then enters the first centrifuge 15 for dewatering treatment to obtain low-ash clean coal, the centrifugal liquid after the dewatering of the first centrifuge 15 is sent to the secondary cleaning flotation machine 16 for secondary flotation, and the concentrate after the secondary flotation is sent to the clean coal filter press 17 for dewatering treatment to obtain low-ash clean coal. Thus, the workload of the roughing flotation machine 13 and the primary cleaning flotation machine 14 is reduced, the primary flotation time is shortened, and the loss of qualified coarse clean slime is reduced.

[0087] The coal slime flotation system provided by the present application, the middlings floated out by the roughing flotation machine 13 are output to the second centrifuge 22 of the medium coal magnetic tail treatment system 2, and the tailings of the primary cleaning flotation machine 14 and the secondary cleaning flotation machine 16 are output to the first thickener 21, and the medium-ash slime is recovered and obtained from the medium coal magnetic tail treatment system 2.

[0088] The coal slime flotation system provided by the present application, the tailings floated out by the roughing flotation machine 13 are output to the third thickener 31, and the high-ash slime is recovered and obtained from the tailings treatment system 3.

[0089] The coal slime flotation system provided by the present application not only improves the yield of the flotation clean coal, but also classifies the slime, which is convenient for subsequent treatment and classified management.

[0090] In one of the embodiments, the first centrifuge 15 and the second centrifuge 22 are both sedimentation filtration type centrifuges, which have both dewatering function and filtration function, and can also grade according to particle size while dewatering to screen out suitable ore or centrifugal liquid.

[0091] In one of the embodiments, the grading particle size of the first centrifuge 15 and the second centrifuge 22 is between 0.04mm-0.05mm, the material with particle size less than 0.04mm will enter the centrifugal liquid, and the material with particle size greater than 0.05mm will be dewatered.

[0092] In one of the embodiments, the grading device 11 includes an arc screen, and the screen gap or screen hole of the arc screen is between 0.15mm-0.2mm. The slime with particle size greater than 0.2mm is coarse slime, and the slime with particle size less than 0.15mm is fine slime.

[0093] The coal slime flotation system provided by the present application relates to coking coal flotation and is used for separating three products of low-ash clean coal, medium-ash slime and high-ash slime.

[0094] Specifically, the clean coal magnetic tail is separated and recovered into three different ash slurry products through the classification device 11, the roughing flotation machine 13, the first cleaning flotation machine 14, the first centrifuge 15 (a sedimentation filtration type centrifugal dehydrator), the second cleaning flotation machine 16, the clean coal filter press 17, the first thickener 21, the second centrifuge 22 (a sedimentation filtration type centrifugal dehydrator), the second thickener 23, the medium coal filter press 24, the third thickener 31, and the tail coal filter press 32.

[0095] The present application selects coal in the following manner:

[0096] The clean coal magnetic tail is coarsely separated by the classification device 11, and the fine particle slurry mixture is fed into the roughing flotation machine 13 (5 chambers in total) as the flotation feed; the concentrate floated in the first three chambers of the roughing flotation machine 13 is fed into the first cleaning flotation machine 14, and the middlings floated in the last two chambers are fed into the second centrifuge 22 for dehydration and recovery; the tailings of the roughing flotation machine 13 are fed into the third thickener 31, and the underflow of the third thickener 31 is pumped into the tail coal filter press 32 by a slurry pump for dehydration and recovery to obtain high-ash slurry. The concentrate floated by the first cleaning flotation machine 14 is combined with the coarse particle slurry mixture screened by the classification device 11 and fed into the first centrifuge 15 for dehydration and recovery. The centrifugal liquid of the first centrifuge 15 is fed into the second cleaning flotation machine 16, the concentrate floated by the second cleaning flotation machine 16 is fed into the clean coal filter press 17 for dehydration and recovery, and the dehydration products of the first centrifuge 15 and the clean coal filter press 17 are combined as the final low-ash clean coal. The tailings and middlings of the first cleaning flotation machine 14 and the second cleaning flotation machine 16, and the clean coal magnetic tail are fed into the first thickener 21, the slurry water in the first thickener 21 is flocculated and settled, the underflow is pumped into the second centrifuge 22 by a slurry pump, the overflow is used as circulating water, the centrifugal liquid of the second centrifuge 22 is fed into the second thickener 23, the underflow of the second thickener 23 is pumped into the medium coal filter press 24 by a slurry pump, and the dehydration products of the medium coal filter press 24 and the second centrifuge 22 are combined as medium-ash slurry.

[0097] As shown in FIG. 1, an embodiment of the present application provides a coal slurry flotation process. Figure 1

[0098] The coal slurry flotation system includes the following steps:

[0099] S1: processing the clean coal magnetic tail by the clean coal magnetic tail processing system 1 to obtain low-ash clean coal.

[0100] S2: processing the clean coal magnetic tail, the middlings and tailings generated by the clean coal magnetic tail processing system 1 by the medium coal magnetic tail processing system 2 to obtain medium-ash slurry.

[0101] S3: processing the high-ash tailings generated by the clean coal magnetic tail processing system 1 by the tailings processing system 3 to obtain high-ash slurry.

[0102] ​Step S1 includes:

[0103] S11: The coarse coal enters the classifier 11 for coarsening. The coarse coal output from the coarse coal slurry output port 111 of the classifier 11 is transported to the first centrifuge 15, and the fine coal slurry output from the fine coal slurry output port 112 of the classifier 11 is transported to the preprocessor 12.

[0104] S12: The coal slime processed by the preprocessor 12 enters the roughing flotation machine 13.

[0105] S13: High-ash tailings output from tailings outlet 133 of roughing flotation machine 13 are transported to third thickener 31.

[0106] The middlings output from the middlings output port 132 of the roughing flotation machine 13 are transported to the second centrifuge 22.

[0107] The concentrate output from the concentrate output port 131 of the roughing flotation machine 13 is transported to the primary cleaning flotation machine 14.

[0108] S14: The concentrate output from the concentrate output port 141 of the primary flotation machine 14 is conveyed to the first centrifuge 15, and the tailings output from the tailings output port 142 of the primary flotation machine 14 are conveyed to the first thickener 21.

[0109] S15: The first centrifuge 15 dewaters to obtain low-ash clean coal, and the centrifugal liquid generated by the first centrifuge 15 is sent to the secondary cleaning flotation machine 16.

[0110] S16: The concentrate output from the concentrate output port 161 of the secondary cleaning flotation machine 16 is transported to the clean coal filter press 17, and the tailings output from the tailings output port 162 of the secondary cleaning flotation machine 16 are transported to the first thickener 21.

[0111] S17: Coal filter press 17 dewaters to obtain low-ash clean coal.

[0112] In one embodiment, such as Figure 1 As shown, in step S17: the overflow generated during the dewatering of the clean coal filter press 17 is used as circulating water.

[0113] In one embodiment, such as Figure 1 As shown, step S2 includes:

[0114] S21: The tailings from the primary flotation machine 14, the secondary flotation machine 16, and the middlings magnetic tailings enter the first thickener 21.

[0115] S22: The underflow from the first thickener 21 and the middlings from the rougher flotation machine 13 are respectively transported to the second centrifuge 22.

[0116] S23: The second centrifuge 22 is used to dewater to obtain medium-ash slime, and the centrifugal liquid of the second centrifuge 22 is delivered to the second thickener 23.

[0117] S24: The underflow of the second thickener 23 is delivered to the medium-coal filter press 24.

[0118] S25: The medium-coal filter press 24 is used to dewater to obtain medium-ash slime.

[0119] In one of the embodiments, as shown in FIG. 5, in step S25, the overflow generated when the medium-coal filter press 24 is dewatered is used as circulating water. Figure 1

[0120] In one of the embodiments, as shown in FIG. 3, in step S3, the following steps are included: Figure 1

[0121] S31: The high-ash tailings of the roughing flotation machine 13 are output to the third thickener 31.

[0122] S32: The underflow of the third thickener 31 is pumped into the tail-coal filter press 32 by a slurry pump.

[0123] S33: The tail-coal filter press 32 is used to dewater to obtain high-ash slime.

[0124] In one of the embodiments, as shown in FIG. 5, in step S33, the overflow generated when the tail-coal filter press 32 is dewatered is used as circulating water. Figure 1

[0125] In summary, the coal slime flotation process provided by the present application is as follows:

[0126] The clean coal magnetic tailings are treated by the clean coal magnetic tail treatment system 1 to obtain low-ash clean coal.

[0127] The medium-coal magnetic tailings and the middlings and tailings generated by the clean coal magnetic tail treatment system 1 are treated by the medium-coal magnetic tail treatment system 2 to obtain medium-ash slime.

[0128] The high-ash tailings generated by the clean coal magnetic tail treatment system 1 are treated by the tailings treatment system 3 to obtain high-ash slime.

[0129] The grading device 11 is used to screen and grade the clean coal magnetic tailings to separate coarse slime and fine slime. The fine slime is output to the pretreater 12 through the fine slime output port 112 of the grading device 11. After being diluted by water, the fine slime water is mixed with flotation reagents in the pretreater 12, and then output to the roughing flotation machine 13 in the tailings treatment system 3.

[0130] ​​​The high-ash tailings floated by the roughing flotation machine 13 are output to the third thickener 31 through a tailings output port 133. The underflow of the third thickener 31 is pumped into the tailings filter press 32 by a slurry pump, and the tailings filter press 32 is used for dewatering and recycling to obtain high-ash slime. The overflow produced during the dewatering of the tailings filter press 32 is used as circulating water. The high-ash slime has high ash content and almost zero calorific value, and can be directly discarded.

[0131] The middlings floated by the roughing flotation machine 13 are output to the second centrifuge 22 through a middlings output port 132.

[0132] The middlings floated by the roughing flotation machine 13 are output to the second centrifuge 22 through a middlings output port 132.

[0133] The middlings floated by the roughing flotation machine 13 are output to the second centrifuge 22 through a middlings output port 132.

[0134] The middlings floated by the roughing flotation machine 13 are output to the second centrifuge 22 through a middlings output port 132.

[0135] The middlings floated by the roughing flotation machine 13 are output to the second centrifuge 22 through a middlings output port 132.

[0136] The middlings floated by the roughing flotation machine 13 are output to the second centrifuge 22 through a middlings output port 132.

[0137] Compared with the prior art, the present application has the following advantages:

[0138] The coal slime flotation system and the coal slime flotation process can effectively improve the separation efficiency and ensure the low-ash clean coal and high-ash coal slime quality. Firstly, the low-ash coarse particle coal slime qualified in ash content is intercepted through the grading equipment 11, the coal slime is not put into the flotation, the flotation feed quantity is reduced, and the loss of the coarse clean coal slime qualified in ash content in the flotation process is avoided. A large amount of high-ash coal slime is excluded through the roughing, the coal slime is directly discarded without causing resource waste; the concentrate is floated through the primary cleaning flotation machine 14, and the coarse particle coal slime is recovered through the first centrifugal machine 15, the coarse clean coal is recovered, and the fine particle coal slime smaller than 0.045 mm is excluded to the centrifugal liquid. The ash reduction is performed again through the secondary cleaning flotation machine 16, the clean coal filter pressing coal slime ash content is ensured, and the clean coal is maximally recovered. The medium coal slime is recovered through the second centrifugal machine 22 and the medium coal filter pressing machine 24, the medium coal slime moisture is reduced, and the medium coal slime added value is increased.

[0139] According to the needs, the above technical solutions can be combined to achieve the best technical effect.

[0140] The above is only the principle and the preferred embodiment of the present application. It should be noted that, for those skilled in the art, on the basis of the principles of the present application, a number of other variants can also be made, which should also be considered as the protection scope of the present application.

Claims

1. A coal slime flotation system, characterized in that, The coal slime flotation system comprises a clean coal magnetic tail processing system, a middling coal magnetic tail processing system and a tailing processing system. The clean coal magnetic tail processing system comprises, in sequence, a classification device, a pre-treater, a roughing flotation machine, a primary cleaning flotation machine, a first centrifuge, a secondary cleaning flotation machine and a clean coal filter press. The middling coal magnetic tail processing system comprises, in sequence, a first thickener, a second centrifuge, a second thickener and a middling coal filter press. The tailing processing system comprises, in sequence, a third thickener and a tailing filter press. The classification device is used for screening and classifying the clean coal magnetic tail, a coarse slime output port of the classification device is connected with the first centrifuge, and coarse particle slime screened by the classification device is directly recovered by the first centrifuge to produce low-ash clean coal. A fine slime output port of the classification device is connected with the pre-treater, fine slime screened by the classification device is output to the pre-treater, diluted, mixed with a flotation reagent in the pre-treater, and then output to the roughing flotation machine. A concentrate output port of the roughing flotation machine is connected with the primary cleaning flotation machine, and concentrate floated by the roughing flotation machine is diluted and output to the primary cleaning flotation machine for re-flotation to float or separate concentrate and tailings. A middlings output port of the roughing flotation machine is connected with the second centrifuge, and middlings floated by the roughing flotation machine are output to the second centrifuge of the middling coal magnetic tail processing system for processing to finally obtain medium-ash slime. A tailings output port of the roughing flotation machine is connected with the third thickener, and high-ash tailings floated by the roughing flotation machine are output to the third thickener of the tailing processing system for dewatering and recovery to obtain high-ash slime. A concentrate output port of the primary cleaning flotation machine is connected with the first centrifuge, and concentrate floated by the primary cleaning flotation machine is fed into the first centrifuge together with coarse slime screened by the classification device for dewatering and recovery to obtain low-ash clean coal. A tailings output port of the primary cleaning flotation machine is connected with the first thickener, and tailings selected by the primary cleaning flotation machine are output to the first thickener of the middling coal magnetic tail processing system for processing to finally obtain medium-ash slime. A concentrate output port of the secondary cleaning flotation machine is connected with the clean coal filter press, and concentrate floated by the secondary cleaning flotation machine is output to the clean coal filter press for dewatering and processing to obtain low-ash clean coal. A tailings output port of the secondary cleaning flotation machine is connected with the first thickener, and tailings selected by the secondary cleaning flotation machine are output to the first thickener of the middling coal magnetic tail processing system for processing to finally obtain medium-ash slime.

2. The coal slurry flotation system of claim 1, wherein, The first centrifuge and the second centrifuge are both sedimentation filtration type centrifuges.

3. The coal slurry flotation system of claim 2, wherein, The classification particle size of the first centrifuge and the second centrifuge is between 0.04 mm and 0.05 mm.

4. The coal slurry flotation system of claim 1, wherein, The classification device comprises an arc-shaped screen, and the screen gap or screen hole of the arc-shaped screen is between 0.15 mm and 0.2 mm.

5. A coal slime flotation process characterised in that, The coal slime flotation system comprises a coal slime flotation system according to any one of claims 1-4. The coal slime flotation system comprises the following steps: S1: processing clean coal magnetic tail by the clean coal magnetic tail processing system to obtain low-ash clean coal; S2: treating the middlings and tailings generated by the middlings magnetic tail treatment system and the clean coal magnetic tail treatment system to obtain medium-ash slime; S3: treating the high-ash tailings generated by the clean coal magnetic tail treatment system to obtain high-ash slime; wherein step S1 comprises: S11: the clean coal magnetic tail enters the classification equipment to cut off coarse coal, the coarse coal output from the coarse slime output port of the classification equipment is transported to the first centrifuge, and the fine coal slime output from the fine slime output port of the classification equipment is transported to the pre-treater; S12: the slime treated by the pre-treater enters the rough flotation machine; S13: the high-ash tailings output from the tailings output port of the rough flotation machine are transported to the third thickener; the middlings output from the middlings output port of the rough flotation machine are transported to the second centrifuge; the clean coal output from the clean coal output port of the rough flotation machine is transported to the primary cleaning flotation machine; S14: the clean coal output from the clean coal output port of the primary cleaning flotation machine is transported to the first centrifuge, and the tailings output from the tailings output port of the primary cleaning flotation machine are transported to the first thickener; S15: the first centrifuge is dehydrated to obtain low-ash clean coal, and the centrifugal liquid generated by the first centrifuge is transported to the secondary cleaning flotation machine; S16: the clean coal output from the clean coal output port of the secondary cleaning flotation machine is transported to the clean coal filter press, and the tailings output from the tailings output port of the secondary cleaning flotation machine are transported to the first thickener; S17: the clean coal filter press is dehydrated to obtain low-ash clean coal.

6. The slime flotation process according to claim 5, wherein, in step S17, the overflow generated during the dehydration of the clean coal filter press is used as circulating water.

7. The slime flotation process according to claim 5, wherein, step S2 comprises: S21: the tailings of the primary cleaning flotation machine, the tailings of the secondary cleaning flotation machine, and the middlings magnetic tail enter the first thickener; S22: the underflow of the first thickener and the middlings of the rough flotation machine are respectively transported to the second centrifuge; S23: the second centrifuge is dehydrated to obtain medium-ash slime, and the centrifugal liquid of the second centrifuge is transported to the second thickener; S24: the underflow of the second thickener is transported to the middlings filter press; S25: the middlings filter press is dehydrated to recover medium-ash slime.

8. The slime flotation process according to claim 7, wherein, in step S25, the overflow generated during the dehydration of the middlings filter press is used as circulating water.

9. The slime flotation process according to claim 5, wherein, step S3 comprises: S31: the high-ash tailings of the rough flotation machine are output to the third thickener; S32: the underflow of the third thickener is pumped into the tailings filter press by a slurry pump; S33: the tailings filter press is dehydrated to recover high-ash slime.

10. The slime flotation process according to claim 9, wherein, in step S33, the overflow generated during the dehydration of the tailings filter press is used as circulating water.

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