Advanced treatment system for easily-argillized coal slime of gangue

Abstract

The utility model discloses an advanced treatment system for easily-argillized coal slime of gangue. Comprising an argillization stirring barrel, a first high-frequency screen, coarse slime separation equipment, a grading cyclone, a first size mixing device, a first flotation machine, a second size mixing device, a second flotation machine, a first-section thickener, a second-section thickener, a first feeding pump, a pressure filter, a filter press, an ultrahigh-pressure filter press, a second feeding pump and a second high-frequency screen. A dispersing agent adding device and a flocculating agent adding device. According to the utility model, pre-argillization is matched with two-stage desliming, so that the influence of easily-argillized gangue on the flotation process is effectively reduced, the particle size range of coarse-grain flotation and fine-grain flotation feeding materials is effectively controlled, and the advanced treatment process of the flotation feeding materials with different particle sizes is innovated by a method and a separation system; and therefore, the ash content of clean coal and the consumption of flotation reagents are reduced, the use efficiency of flotation system equipment is improved, and a new solution thought is provided for the problem of difficulty in deep treatment of the coal slime with easily-argillized gangue.

Description

Technical Field

[0001] The utility model belongs to the technical field of ore dressing, and in particular relates to a system for deep processing of gangue easily sludged coal slime. Background Art

[0002] Flotation is a common beneficiation method for coal slime with a particle size of less than 0.5 mm. When the coal contains gangue that is easy to be sludged, there is often a serious phenomenon of gangue sludge in the flotation process; according to statistics, the flotation feed of many coal preparation plants has a high content of particles less than 0.074 mm or less than 0.045 mm, and the ash content of these fine-grained coal slimes is much higher than that of coarse-grained coal slimes. In this case, there are usually problems such as high-ash fine slime deteriorating flotation, large consumption of flotation reagents, and affecting the floatability of coal slimes. For coal slime flotation, coarse-grained coal slime has good selectivity, fine-grained coal slime has poor selectivity, and medium-sized coal particles have good floatability. Coarse particles have less pollution to clean coal, while fine impurities have the most serious pollution to clean coal. Fine-grained coal slime "adsorbs flotation reagents first", which reduces the chance of coarse particles contacting with reagents, reduces hydrophobicity, and increases the difficulty of adhering to bubbles, thereby affecting the clean coal indicators. When the content of coarse and medium particles in the coal slime is high, the overall flotation speed is not fast, but the separation is relatively stable, and the clean coal yield is the highest. When the content of fine particles is high, the flotation speed and the final clean coal yield are both low. It is generally believed that the optimal coal slime flotation particle size range is 0.25mm~0.074mm or 0.045mm. Therefore, based on the above analysis, a deep treatment system and process system for gangue-prone coal slime is designed, in order to provide a certain reference for the problems of serious clean coal pollution and large reagent consumption in the flotation of gangue-prone coal slime, and further improve the technical and economic benefits of the enterprise. Utility Model Content

[0003] The utility model aims at the problems of serious pollution of flotation clean coal and large consumption of reagents in the deep treatment of gangue easily muddy coal slime, and provides a gangue easily muddy coal slime deep treatment system which can effectively control the particle size range of coarse particle flotation and fine particle flotation feed, effectively reduce the ash content of clean coal, flotation reagent consumption and improve the production efficiency of equipment.

[0004] In order to solve the above technical problems, the utility model adopts the following technical solutions: a deep processing system for coal slime easily sludged by gangue, comprising a sludge mixing barrel, a first high-frequency screen, a coarse coal slime sorting device, a grading cyclone, a first slurry mixing device, a first flotation machine, a second slurry mixing device, a second flotation machine, a first-stage thickener, a second-stage thickener, a first feed pump, a pressure filter, a filter press, an ultra-high-pressure filter press, a second feed pump and a second high-frequency screen;

[0005] The discharge port of the slime mixing barrel is connected to the feed port of the first high-frequency screen. The oversize discharge port of the first high-frequency screen is connected to the feed port of the coarse slime separation equipment. The undersize discharge port of the first high-frequency screen is connected to the feed port of the classification cyclone. The bottom discharge port of the classification cyclone is connected to the feed port of the second high-frequency screen. The overflow port of the classification cyclone and the undersize discharge port of the second high-frequency screen are connected to the feed port of the first thickener. The oversize discharge port of the second high-frequency screen is connected to the feed port of the first pulp mixing device. The discharge port of the first pulp mixing device is connected to the feed port of the first flotation machine. The bottom discharge port of the first thickener is connected to the feed port of the second pulp mixing device through the first feed pump. The overflow discharge port of the first thickener is connected to the feed port of the second thickener. The discharge port of the second pulp mixing device is connected to the feed port of the second flotation machine. The tailing discharge port of the second flotation machine is connected to the feed port of the second thickener. The clean coal discharge port of the second flotation machine is connected to the feed port of the filter press. The bottom discharge port of the second thickener is connected to the feed port of the ultra-high pressure filter press through the second feed pump. The clean coal discharge port of the first flotation machine is connected to the feed port of the pressure filter. The tailing discharge port of the first flotation machine is connected to the feed port of the ultra-high pressure filter press. The filtrate discharge port of the pressure filter is connected to the feed port of the first thickener.

[0006] The feed port of the first pulp mixing device is connected with a dispersant adding device through a first pipeline.

[0007] The feed port of the second pulp mixing device is connected with a flocculant adding device through a second pipeline.

[0008] It further includes a circulating water tank. The circulating water outlets of the filter press, the ultra-high pressure filter press and the second thickener are all connected to the water inlet of the circulating water tank. The water outlet of the circulating water tank is connected to the feed port of the second flotation machine.

[0009] Adopting the above technical solution, the process of the utility model for deeply treating the gangue-susceptible-to-slime slime includes the following steps:

[0010] (1) The coal slime to be floated is transported to the slime mixing barrel for stirring to fully slime the gangue.

[0011] (2) The slime-formed coal slime to be floated is screened and sized by the first high-frequency screen, and the sized material is transported to the coarse slime separation equipment.

[0012] (3) The undersize product of the first high-frequency screen enters the classification cyclone for preliminary classification.

[0013] (4) The bottom flow material of the classification cyclone enters the second high-frequency screen for strict classification; the oversize material after strict classification by the second high-frequency screen enters the first pulp mixing device for pulp mixing, and the dispersant adding device adds dispersant into the first pulp mixing device during the pulp mixing process; the overflow from the preliminary classification by the classification cyclone, the undersize product from the strict classification by the second high-frequency screen and the filtrate of the pressure filter enter the first thickener together.

[0014] (5) After the coarse coal slurry is slurried, it enters the first flotation machine for sorting. The sorted products are processed by a pressure filter and an ultra-high pressure filter press to obtain clean coal products and tail coal products. The filtrate of the pressure filter enters a first concentrator, and the filtrate of the ultra-high pressure filter press is used as circulating water;

[0015] (6) The overflow of the first-stage thickener enters the second-stage thickener, and the underflow of the first-stage thickener enters the second slurry mixing device to float the fine coal slime to a high concentration. During the slurry mixing process, the flocculant adding device adds flocculant to the second slurry mixing device; after slurry mixing, the fine coal slime enters the second flotation machine and is flotated at a low concentration by adding circulating water; the clean coal after flotation of the fine coal slime is dehydrated by a filter press to obtain fine clean coal and filtrate, and the filtrate is used as circulating water; the tail coal after flotation of the fine coal slime and the overflow of the first-stage thickener enter the second-stage thickener together, and the underflow of the second-stage thickener is filtered by an ultra-high pressure filter press, and the overflow of the second-stage thickener is used as circulating water.

[0016] Compared with the prior art, the utility model has outstanding substantive features and significant progress. Specifically, the utility model first takes into account that the coal slime that is easily muddied by gangue has a high content of high-ash fine-grained coal slime. In the continued processing process, this part of high-ash fine-grained coal slime will inevitably affect the overall coal slime sorting effect. Therefore, it is considered to remove the fine-grained coal slime in advance. Pre-removal of fine-grained coal slime will help avoid the problem of fine-grained coal slime "preemptively adsorbing flotation agents" and effectively reduce flotation agent consumption. Before removal, the floating coal slime first enters the mudification stirring barrel that is set. The mudification stirring barrel can fully muddy the part of the gangue that may continue to muddy in the subsequent sorting. After sufficient muddying, the fine-grained coal slime removal process can be considered.

[0017] Then consider the combination of grading cyclone + high-frequency screen in the process of removing fine-grained coal slime. This is because after sufficient mudification, the content of materials below 0.074 / 0.045mm particle size is relatively high, and the desludging effect is not good at one time. In addition, the grading process of the grading cyclone is based on the difference in particle settling velocity, so it is not strictly graded by particle size. Therefore, it is necessary to rely on two grading to achieve a relatively sufficient grading of coal slime. After two gradings, the fine mud content in the coarse-grained coal slime is effectively reduced, but a small part still exists. The material on the second high-frequency screen enters the coarse-grained flotation slurry mixing equipment for slurry mixing. Dispersants (water glass, sodium hexametaphosphate) are added during the slurry mixing process to prevent the fine-grained coal slime remaining after grading from non-selectively agglomerating during the flotation process of the coarse-grained coal slime, thereby affecting the flotation effect of the coarse-grained coal slime. In actual situations, the grading particle size (0.074mm or 0.045mm) should be comprehensively determined based on the particle content and ash content in the experimental results.

[0018] Finally, there is still some fine clean coal that has not been effectively separated in the clean coal filtrate after the separation of coarse clean coal slime. Returning the filtrate to the first-stage thickener can help to fully recover it in the flotation of fine clean coal slime. The main function of the first-stage thickener is to provide a suitable feed concentration (60%) for high-concentration pulp preparation in flotation. Among them, extremely fine ash particles and materials with slower floating or settling speeds enter the second-stage thickener with the overflow of the first-stage thickener. A suitable flocculant is added to the high-concentration pulp preparation in flotation to help the fine clean coal form flocs and perform flotation under low-concentration conditions. This is because fine clean coal slime is small in volume, light in weight, and difficult to mineralize. High-concentration pulp preparation is beneficial to increasing the collision probability between particles and reagents, and effective flocculation can also improve the flotation effect of fine particle sizes. After the flotation of fine clean coal slime, since the clean coal has a relatively fine particle size, filter pressing dehydration is used; the tail coal also has a relatively fine particle size, so it enters the second-stage thickener, and flocculants, coagulants, etc. are added during this process to achieve the effective settlement of fine tail coal particles. The underflow material of the second-stage thickener is also relatively fine, so ultra-high pressure filter pressing is required to complete the final dehydration.

[0019] Therefore, compared with conventional direct flotation, since the present utility model realizes sufficient agitation and slime-making and two-stage desliming processes before the coal slime is fed, the pollution of clean coal by materials smaller than 0.074 mm (0.045 mm) can be effectively reduced in the flotation of coarse clean coal slime, the ash content of flotation clean coal can be reduced, and the consumption of flotation reagents can be reduced. In the filtration of clean coal and the filter pressing of tail coal, since the content of materials smaller than 0.074 mm (0.045 mm) in the feed particle size is very small, the filter pressing and filtration efficiency are improved, and it helps to reduce the product moisture. In the flotation of fine clean coal slime, the method of high-concentration pulp preparation + flocculant flotation provides guarantee for the separation quality of fine particle size coal slime.

[0020] In summary, the present utility model adopts pre-slime-making combined with two-stage desliming to effectively reduce the influence of easily slime-forming gangue on the flotation process, effectively control the feed particle size range of coarse particle flotation and fine particle flotation, and innovate the methods and separation systems for the in-depth treatment process of flotation feed with different particle sizes. Furthermore, it helps to reduce the ash content of clean coal, the consumption of flotation reagents, improve the use efficiency of flotation system equipment, and provides a new solution idea for the difficult problem of in-depth treatment of gangue with easily slime-forming coal slime. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic structural diagram of the present utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the drawings in the embodiments of the present utility model.

[0023] Such as Figure 1As shown in the figure, a deep treatment system for gangue-susceptible slime coal slime of the present utility model includes a slime mixing tank 1, a first high-frequency screen 2, a coarse coal slime separation device 3, a classification cyclone 4, a first pulp adjusting device 5, a first flotation machine 6, a second pulp adjusting device 7, a second flotation machine 8, a first thickener 9, a second thickener 10, a first feed pump 11, a pressure filter 12, a filter press 13, an ultra-high pressure filter press 14, a second feed pump 15, and a second high-frequency screen 16;

[0024] The discharge port of the slime mixing tank 1 is connected to the feed port of the first high-frequency screen 2. The oversize discharge port of the first high-frequency screen 2 is connected to the feed port of the coarse coal slime separation device 3. The undersize discharge port of the first high-frequency screen 2 is connected to the feed port of the classification cyclone 4. The bottom discharge port of the classification cyclone 4 is connected to the feed port of the second high-frequency screen 16. The overflow port of the classification cyclone 4 and the undersize discharge port of the second high-frequency screen 16 are connected to the feed port of the first thickener 9. The oversize discharge port of the second high-frequency screen 16 is connected to the feed port of the first pulp adjusting device 5. The discharge port of the first pulp adjusting device 5 is connected to the feed port of the first flotation machine 6. The underflow outlet of the first thickener 9 is connected to the feed port of the second pulp adjusting device 7 through the first feed pump 11. The overflow outlet of the first thickener 9 is connected to the feed port of the second thickener 10. The discharge port of the second pulp adjusting device 7 is connected to the feed port of the second flotation machine 8. The tail coal outlet of the second flotation machine 8 is connected to the feed port of the second thickener 10. The clean coal outlet of the second flotation machine 8 is connected to the feed port of the filter press 13. The underflow outlet of the second thickener 10 is connected to the feed port of the ultra-high pressure filter press 14 through the second feed pump 15. The clean coal outlet of the first flotation machine 6 is connected to the feed port of the pressure filter 12. The tail coal outlet of the first flotation machine 6 is connected to the feed port of the ultra-high pressure filter press 14. The filtrate outlet of the pressure filter 12 is connected to the feed port of the first thickener 9.

[0025] The feed port of the first pulp adjusting device 5 is connected with a dispersant adding device 17 through a first pipeline.

[0026] The feed port of the second pulp adjusting device 7 is connected with a flocculant adding device 18 through a second pipeline.

[0027] The present utility model further includes a circulating water tank. The circulating water outlets of the filter press 13, the ultra-high pressure filter press 14, and the second thickener 10 are all connected to the water inlet of the circulating water tank. The water outlet of the circulating water tank is connected to the feed port of the second flotation machine 8.

[0028] The process of the present utility model for deeply treating gangue-susceptible slime coal slime includes the following steps:

[0029] (1) The coal slime to be floated is transported to the slime mixing tank 1 for stirring to fully slime the gangue;

[0030] (2) The slime-formed floatable slime is screened and coarseness-cut by the first high-frequency screen 2, and the coarseness-cut slime is conveyed to the coarse slime separation equipment 3;

[0031] (3) The undersize product passing through the first high-frequency screen 2 enters the classification cyclone 4 for preliminary classification;

[0032] (4) The underflow material of the classification cyclone 4 enters the second high-frequency screen 16 for strict classification; the oversize material after strict classification by the second high-frequency screen 16 enters the first pulp mixing device 5 for pulp mixing, and during the pulp mixing process, the dispersant adding device 17 adds dispersant into the first pulp mixing device 5; the overflow from the preliminary classification by the classification cyclone 4, the undersize product from the strict classification by the second high-frequency screen 16, and the filtrate of the pressure filter 12 all enter the first-stage thickener 9;

[0033] (5) After the coarse slime is pulped, it enters the first flotation machine 6 for separation. The separated products are respectively processed by the pressure filter 12 and the ultra-high pressure filter press 14 to obtain clean coal products and tail coal products. The filtrate of the pressure filter 12 enters the first-stage thickener 9, and the filtrate of the ultra-high pressure filter press 14 is used as circulating water;

[0034] (6) The overflow of the first-stage thickener 9 enters the second-stage thickener 10, and the underflow of the first-stage thickener 9 enters the second pulp mixing device 7 for high-concentration pulp mixing for the flotation of fine slime. During the pulp mixing process, the flocculant adding device 18 adds flocculant into the second pulp mixing device 7; after the fine slime is pulped, it enters the second flotation machine 8 for low-concentration flotation by adding circulating water; the clean coal after the flotation of the fine slime is dehydrated by the filter press 13 to obtain fine clean coal and filtrate, and the filtrate is used as circulating water; the tail coal after the flotation of the fine slime and the overflow of the first-stage thickener 9 enter the second-stage thickener 10 together. The underflow of the second-stage thickener 10 is filtered by the ultra-high pressure filter press 14, and the overflow of the second-stage thickener 10 is used as circulating water.

[0035] It should be emphasized that the slime mixing tank 1, the first high-frequency screen 2, the coarse slime separation equipment 3, the classification cyclone 4, the first pulp mixing device 5, the first flotation machine 6, the second pulp mixing device 7, the second flotation machine 8, the first-stage thickener 9, the second-stage thickener 10, the first feed pump 11, the pressure filter 12, the filter press 13, the ultra-high pressure filter press 14, the second feed pump 15, the dispersant adding device 17, and the flocculant adding device 18 in the present utility model are all existing equipment and can be purchased on the market. Therefore, the specific structure and working principle will not be elaborated herein.

[0036] The above two embodiments do not impose any formal restrictions on the shape, material, structure, etc. of the present utility model. Any simple modification, equivalent change, and modification made to the above embodiments based on the technical essence of the present utility model all fall within the protection scope of the technical solution of the present utility model.

Claims

1. A system for deep treatment of coal slime easily transformed from gangue, characterized by: It includes a mud-mixing barrel, a first high-frequency screen, a coarse coal slime sorting device, a grading cyclone, a first slurry mixing device, a first flotation machine, a second slurry mixing device, a second flotation machine, a first-stage thickener, a second-stage thickener, a first feed pump, a pressure filter, a filter press, an ultra-high-pressure filter press, a second feed pump, and a second high-frequency screen; The discharge port of the mud-forming mixing barrel is connected to the feed port of the first high-frequency screen, the upper discharge port of the first high-frequency screen is connected to the feed port of the coarse coal slime sorting equipment, the lower discharge port of the first high-frequency screen is connected to the feed port of the grading cyclone, the underflow discharge port of the grading cyclone is connected to the feed port of the second high-frequency screen, the overflow port of the grading cyclone and the lower discharge port of the second high-frequency screen are connected to the feed port of the first thickener, the upper discharge port of the second high-frequency screen is connected to the feed port of the first slurry mixing device, the discharge port of the first slurry mixing device is connected to the feed port of the first flotation machine, the underflow outlet of the first thickener is connected to the second slurry mixing device through the first feeding pump. The first thickener is connected to the feed port of the second thickener, the overflow outlet of the first thickener is connected to the feed port of the second thickener, the discharge port of the second slurry mixing device is connected to the feed port of the second flotation machine, the tail coal outlet of the second flotation machine is connected to the feed port of the second thickener, the clean coal outlet of the second flotation machine is connected to the feed port of the filter press, the underflow outlet of the second thickener is connected to the feed port of the ultra-high pressure filter press through the second feeding pump, the clean coal outlet of the first flotation machine is connected to the feed port of the pressure filter, the tail coal outlet of the first flotation machine is connected to the feed port of the ultra-high pressure filter press, and the filtrate outlet of the pressure filter is connected to the feed port of the first thickener.

2. A system for deep treatment of coal slime easily transformed from gangue according to claim 1, characterized in that: The feed inlet of the first slurry mixing device is connected with a dispersant adding device through a first pipeline.

3. The system for deep treatment of coal slime easily transformed from gangue according to claim 1, characterized in that: The feed inlet of the second slurry adjusting device is connected with a flocculant adding device through a second pipeline.

4. The system for deep treatment of coal slime easily transformed from gangue according to claim 1, characterized in that: It also includes a circulating water pool, the circulating water outlets of the filter press, the circulating water outlets of the ultrahigh pressure filter press and the circulating water outlets of the second stage concentrator are all connected to the water inlet of the circulating water pool, and the water outlet of the circulating water pool is connected to the feed port of the second flotation machine.

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