A process for reseparating waste coal gangue

Abstract

The application discloses a kind of waste coal gangue reseparation processes, it is related to coal gangue sorting technical field, for solving present coal gangue sorting process sorting precision low, poor adaptability, cannot realize the effective sorting of refractory slime or very refractory slime technical problem, a kind of waste coal gangue reseparation process, including coal gangue crushing, grading desliming, coarse slime dense medium separation, coarse slime recovery, heavy medium recovery, fine slime flotation, fine slime and tail slime dewatering, the sorting precision of this sorting process is good, overall recovery rate is high, the adaptability of coal gangue and slime is strong, can effectively sort refractory slime or very refractory slime, effectively recover the useful components of coarse, fine particle size in crushing coal gangue, greatly improve the utilization rate of coal gangue, solve the present coal gangue sorting process sorting precision low, poor adaptability, cannot realize the effective sorting of refractory slime or very refractory slime technical problem.

Description

Technical Field

[0001] This invention relates to the field of coal gangue sorting technology, and in particular to a waste coal gangue re-sorting process. Background Technology

[0002] Coal gangue is a solid waste generated during coal production and processing, and it is a type of rock that is associated with and coexists with coal during coal formation. Currently, under the conditions of coal mine production in my country, the amount of gangue discharged during coal mining is approximately 10% to 20% of the raw coal output; the amount of gangue discharged during coal washing and processing is approximately 15% to 20% of the raw coal input. Statistics show that my country currently has over 5 billion tons of coal gangue stockpiles, with an annual discharge of approximately 750 million tons. Coal gangue is the largest solid waste in terms of discharge volume and land occupation among various industrial wastes. Open-air stockpiling of coal gangue not only impacts the natural landscape of mining areas but also causes serious environmental pollution, making it one of the main sources of pollution in the ecological environment of mining areas, and sometimes even leading to disasters such as landslides and mudslides.

[0003] Although coal gangue is a type of solid waste, it also contains several useful components, making it a usable resource. Coal gangue typically has a lime content greater than 50%, containing a certain amount of combustible materials (such as residual coal, pyrite, and carbonaceous shale). The fixed carbon content is generally between 10% and 30%, with a calorific value ranging from over 12,000 kJ / kg to approximately 6,000 kJ / kg. For coal gangue with a high fixed carbon content, further sorting can be performed to extract useful fixed carbon. Developing and utilizing coal gangue as a resource is not only an effective way to address the environmental hazards caused by coal gangue stockpiling, but also a way to turn waste into treasure and maximize its economic value.

[0004] Patent CN101869877B, authorized on January 25, 2012, entitled "A Sorting Process for Coal Gangue," discloses a sorting process for coal gangue. This process separates coal gangue using main and rewash hydrocyclones, producing a sulfur concentrate with a sulfur content ≥28.4%, blister coal ash content <70%, and kaolin ash content >80%, thus improving the recovery rate of the sulfur concentrate and reducing the sulfur content of the blister coal. The drawback of this sorting process is its low sorting accuracy for fine-grained coal slime, and it cannot achieve full-scale recovery of useful components from the ground coal gangue.

[0005] The authorized patent CN103861725B, published on January 13, 2016, entitled "Sorting and Processing Technology for the Full Resource Utilization of Coal Gangue," discloses a sorting and processing technology for the full resource utilization of coal gangue. This technology employs both gravity separation and flotation, achieving zero waste in the sorted coal gangue products, converting all sorted products into directly usable industrial products or raw materials. Compared with the patent application No. 201010195059.2, the most significant feature of this technology is the use of a flotation mode consisting of coarse selection, scavenging, and two cleaning stages, achieving effective recovery of fine-grained coal slime. However, the technology has shortcomings. It uses a trapezoidal jig as a gravity separation device to separate coarse-grained coal slime. The trapezoidal jig has low separation accuracy and poor adaptability to coal slime, making it unable to effectively separate difficult or extremely difficult-to-separate coal slime.

[0006] Therefore, in view of the shortcomings of the above-mentioned solutions in actual production and implementation, modifications and improvements have been made. At the same time, in the spirit and concept of seeking excellence, and with the assistance of professional knowledge and experience, and after much ingenuity and experimentation, a waste coal gangue re-sorting process is provided to solve the technical problems of low sorting accuracy, poor adaptability and inability to effectively sort difficult or extremely difficult coal slime in the current coal gangue sorting process. Summary of the Invention

[0007] The purpose of this invention is to provide a waste coal gangue re-sorting process to solve the technical problems of low sorting accuracy, poor adaptability, and inability to effectively sort difficult or extremely difficult coal slime in current coal gangue sorting processes.

[0008] The technical solution of this invention is implemented as follows:

[0009] A waste coal gangue re-sorting process includes coal gangue crushing, classification and desliming, coarse coal slime heavy medium separation, coarse coal slime recovery, heavy medium recovery, fine coal slime flotation, and dewatering of fine coal slime and tailings slime.

[0010] S1: Coal gangue crushing:

[0011] To fix carbon embedded in coal gangue, the coal gangue is crushed to a particle size of less than 3.0 mm. Only by crushing the coal gangue to a particle size of less than 3.0 mm can the fixed carbon be fully dissociated.

[0012] S2: Staged desliming:

[0013] Coal gangue pulverized material with a particle size of less than 3.0 mm is mixed with water in a mixing tank to form coal slurry. The slurry is then pumped into a first-stage hydrocyclone for classification and desliming. After classification by the first-stage hydrocyclone, the underflow from the first-stage hydrocyclone enters a second-stage hydrocyclone for further classification. The underflow from the second-stage hydrocyclone, which contains coarse particles, enters the heavy medium separation operation, while the overflow from the first-stage and second-stage hydrocyclones, which contains fine particles, enters the flotation operation together.

[0014] S3: Coarse coal slime heavy media separation:

[0015] The underflow from the two-stage hydraulic classifier enters the coarse coal slime bucket and is mixed with the heavy medium. It is then pumped into the coal slime heavy medium hydrocyclone for separation. The overflow from the coal slime heavy medium hydrocyclone after separation is used for coarse coal slime recycling.

[0016] S4: Coarse coal slime recovery:

[0017] The overflow from the coal slime heavy medium hydrocyclone enters a high-frequency screen for dewatering. The material on the high-frequency screen then enters a coal slime centrifugal dewatering machine for further dewatering, becoming coarse and fine coal slime.

[0018] S5: Heavy Media Recovery

[0019] The underflow of the coal slime heavy medium hydrocyclone containing heavy medium and the underflow of the high frequency screen enter the magnetic separator for heavy medium recovery. After recovery, the concentrate of the magnetic separator and the filtrate of the coal slime centrifugal dewatering machine are sent together to the coarse coal slime bucket for recycling.

[0020] S6: Fine coal slime flotation:

[0021] The overflow from the first-stage and second-stage hydrocyclones, along with the tailings from the magnetic separator, enter the fine coal slime bucket. After being pumped into the slurry pre-processor and mixed evenly with flotation reagents, the slurry enters the roughing flotation machine for pre-separation.

[0022] To improve the flotation effect, the overflow of the roughing flotation machine enters the cleaning flotation machine for further separation, the overflow of the cleaning flotation machine enters the next dewatering operation, and the underflow of the cleaning flotation machine is returned to the roughing flotation machine for further separation.

[0023] To prevent the coal slime from becoming coarse, the underflow from the roughing flotation machine enters the scavenging flotation machine for further separation, the overflow from the scavenging flotation machine is returned to the cleaning flotation machine for further separation, and the underflow from the scavenging flotation machine enters the next dewatering operation.

[0024] S7: Fine coal slime and tailings dewatering and recovery:

[0025] The overflow from the fine flotation machine enters the coal slime filter press for dewatering and becomes fine coal slime filter cake; the underflow from the scavenging flotation machine enters the tailings filter press for dewatering and becomes tailings filter cake; the filtrate from the coal slime filter press and the tailings filter press is returned to the mixing tank for recycling.

[0026] The inherent properties of coal gangue can be adjusted by changing the number of two-stage hydrocyclones, fine flotation machines, and scavenging flotation machines to improve the separation quality of coarse coal slime, fine coal slime, and tailings slime.

[0027] In one preferred embodiment, the coal gangue crushing in S1 adopts a two-stage closed crushing method: the coal gangue first enters the coarse crusher, and after preliminary crushing, it enters the coarse crushing and grading screen. The material on the coarse crushing and grading screen is returned to the coarse crusher for further crushing, and the material under the coarse crushing and grading screen enters the fine crusher for further crushing. After being crushed by the fine crusher, it enters the fine crushing and grading screen. The material on the fine crushing and grading screen is returned to the fine crusher for further crushing, and the material under the fine crushing and grading screen enters the pulverizer to be crushed to a particle size of less than 3.0 mm.

[0028] This waste coal gangue re-sorting process includes seven steps: coal gangue crushing, classification and desliming, coarse coal slime heavy medium separation, coarse coal slime recovery, heavy medium recovery, fine coal slime flotation, and dewatering and recovery of fine coal slime and tailings slime. It employs a two-stage closed crushing and pulverizing system to crush the coal gangue to below 3.0 mm. The crushed coal gangue is mixed with water in a mixing tank to form a coal slime solution of a certain concentration, which is then pumped into two-stage, series-connected hydrocyclones for classification and desliming. The underflow from the second-stage hydrocyclone enters the coarse coal slime tank and is mixed with the heavy medium, which is then pumped into the coal slime heavy medium. Hydrocyclone separation: The overflow of the heavy medium hydrocyclone for coal slime enters a high-frequency screen for dewatering. The oversize material from the high-frequency screen enters a coal slime centrifugal dewatering machine for further dewatering to become coarse and fine coal slime. The underflow of the heavy medium hydrocyclone containing heavy medium and the undersize material from the high-frequency screen enter a magnetic separator for heavy medium recovery. The concentrate from the magnetic separator and the filtrate from the coal slime centrifugal dewatering machine are sent together to a coarse coal slime tank for recycling. The overflow of the first and second stage hydraulic classification hydrocyclones and the tailings from the magnetic separator enter the flotation operation. After roughing, scavenging and cleaning stages, the coal slime is separated into fine coal slime and tailings.

[0029] The waste coal gangue re-sorting process of this invention mainly includes three stages: coal gangue crushing, coarse particle heavy medium separation, and fine particle flotation. It can effectively recover coarse and fine-grained clean coal from the crushed coal gangue, greatly improving the clean coal recovery rate. Before separation, a two-stage closed crushing and pulverizing process is used to crush the coal gangue to below 3.0 mm to ensure that the fixed carbon embedded in the coal gangue is fully dissociated. A two-stage hydraulic classifier is used to classify and deslim the coal slime water in advance, providing a suitable feed particle size for heavy medium separation and flotation, improving the separation efficiency and accuracy of heavy medium separation and flotation. The coal slime heavy medium cyclone separation has strong adaptability to coal slime and can effectively separate difficult-to-separate coal slime. The three-stage flotation mode of coarsening, scavenging, and cleaning maximizes the recovery rate of fine-grained coal slime.

[0030] Waste coal gangue is separated into three products—coarse clean coal slime, fine clean coal slime, and tailings slime—using the separation process described in this invention. The quality of the clean coal slime is related to the hydrocyclone classifier. When the heavy medium hydrocyclone is unavailable, the quality of the clean coal slime can be effectively improved by changing the number of hydrocyclones connected in series. Similarly, the quality of the fine clean coal slime and tailings slime can be improved by changing the number of cleaning and scavenging flotation machines. Therefore, this separation process is highly flexible.

[0031] In summary, this sorting process offers high sorting accuracy and overall recovery rate. It is highly adaptable to coal gangue and coal slime, effectively sorting difficult or extremely difficult coal slime. It effectively recovers useful components from both coarse and fine particles in crushed coal gangue, greatly improving the utilization rate of coal gangue. This process solves the technical problems of low sorting accuracy, poor adaptability, and inability to effectively sort difficult or extremely difficult coal slime in current coal gangue sorting processes. It enables the sorting and reuse of waste coal gangue while avoiding environmental pollution caused by large-scale coal gangue accumulation. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a flowchart of the process of the present invention.

[0034] The markings in the image are as follows:

[0035] 1-Coarse crusher, 2-Coarse crushing and grading screen, 3-Fine crusher, 4-Fine crushing and grading screen, 5-Pulverizer, 6-Agitator, 7-First-stage hydrocyclone, 8-Second-stage hydrocyclone, 9-Coarse coal slime bucket, 10-Coal slime heavy medium hydrocyclone, 11-High frequency screen, 12-Coal slime centrifugal dewatering machine, 13-Magnetic separator, 14-Fine coal slime bucket, 15-Slurry preprocessor, 16-Roughing flotation machine, 17-Finishing flotation machine, 18-Scavenging flotation machine, 19-Coal slime filter press, 20-Tailings filter press.

[0036] In the diagram, "+" represents the underflow, the oversize of the coarse and fine crushing grading screen, the oversize of the high-frequency screen, the filter cake of the coal slime centrifugal dewatering machine, the tailings of the magnetic separator, and the filter cake of the filter press; "-" represents the overflow, the undersize of the coarse and fine crushing grading screen, the undersize of the high-frequency screen, the filtrate of the coal slime centrifugal dewatering machine, the concentrate of the magnetic separator, and the filtrate of the filter press. Detailed Implementation

[0037] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0038] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0039] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features.

[0040] In the description of the embodiments, unless otherwise explicitly specified and limited, the terms "set," "connect," etc., should be interpreted broadly. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or a connection through an intermediate medium, or it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0041] like Figure 1 As shown, a waste coal gangue re-sorting process includes coal gangue crushing, grading and desliming, coarse coal slime heavy medium separation, coarse coal slime recovery, heavy medium recovery, fine coal slime flotation, and dewatering of fine coal slime and tailings slime.

[0042] S1: Coal gangue crushing:

[0043] To fix carbon embedded in coal gangue, the coal gangue is crushed to a particle size of less than 3.0 mm. Only by crushing the coal gangue to a particle size of less than 3.0 mm can the fixed carbon be fully dissociated.

[0044] The coal gangue in S1 is crushed using a two-stage closed crushing method: the coal gangue first enters the coarse crusher 1, and after preliminary crushing, it enters the coarse crushing and grading screen 2. The material oversized by the coarse crushing and grading screen 2 is returned to the coarse crusher 1 for further crushing. The material undersized by the coarse crushing and grading screen 2 enters the fine crusher 3 for further crushing. After being crushed by the fine crusher 3, it enters the fine crushing and grading screen 4. The material oversized by the fine crushing and grading screen 4 is returned to the fine crusher 3 for further crushing. The material undersized by the fine crushing and grading screen 4 enters the pulverizer 5 and is pulverized to a particle size of less than 3.0 mm.

[0045] S2: Staged desliming:

[0046] Coal gangue pulverized material with a particle size of less than 3.0 mm is mixed with water in a mixing tank 6 to form coal slurry water. It is then pumped into a first-stage hydrocyclone 7 for classification and desliming. After classification by the first-stage hydrocyclone 7, the underflow of the first-stage hydrocyclone 7 enters the second-stage hydrocyclone 8 for further classification. The underflow of the second-stage hydrocyclone 8 with coarse particles enters the heavy medium separation operation, while the overflow of the first-stage hydrocyclone 7 and the second-stage hydrocyclone 8 with fine particles enters the flotation operation together.

[0047] S3: Coarse coal slime heavy media separation:

[0048] The underflow from the second-stage hydraulic classifier 8 enters the coarse coal slime bucket 9 and is mixed with the heavy medium. It is then pumped into the coal slime heavy medium hydrocyclone 10 for separation. The overflow from the coal slime heavy medium hydrocyclone 10 after separation enters the coarse coal slime recycling operation.

[0049] S4: Coarse coal slime recovery:

[0050] The overflow of the coal slime heavy medium hydrocyclone 10 enters the high frequency screen 11 for dewatering. The material on the high frequency screen 11 enters the coal slime centrifugal dewatering machine 12 for further dewatering and becomes coarse and fine coal slime.

[0051] S5: Heavy Media Recovery

[0052] The underflow of coal slime from the heavy medium hydrocyclone 10 containing heavy media and the underflow from the high frequency screen 11 enter the magnetic separator 13 for heavy medium recovery. After recovery, the concentrate from the magnetic separator 13 and the filtrate from the coal slime centrifugal dewatering machine 12 are sent together to the coarse coal slime bucket 9 for recycling.

[0053] S6: Fine coal slime flotation:

[0054] The overflow from the first-stage hydrocyclone 7 and the second-stage hydrocyclone 8, along with the tailings from the magnetic separator 13, enter the fine coal slime bucket 14. After being pumped into the slurry pre-processor 15 and mixed evenly with the flotation reagents, the slurry enters the roughing flotation machine 16 for pre-separation.

[0055] To improve the flotation effect, the overflow of the roughing flotation machine 16 enters the cleaning flotation machine 17 for further separation, the overflow of the cleaning flotation machine 17 enters the next dewatering operation, and the underflow of the cleaning flotation machine 17 is returned to the roughing flotation machine 16 for further separation.

[0056] To prevent the coal slime from becoming coarse, the underflow from the roughing flotation machine 16 enters the scavenging flotation machine 18 for further separation. The overflow from the scavenging flotation machine 18 is returned to the cleaning flotation machine 17 for further separation. The underflow from the scavenging flotation machine 18 enters the next dewatering operation.

[0057] S7: Fine coal slime and tailings dewatering and recovery:

[0058] The overflow from the fine flotation machine 17 enters the coal slime filter press 19 for dewatering and becomes fine coal slime filter cake; the underflow from the scavenging flotation machine 18 enters the tailings filter press 20 for dewatering and becomes tailings filter cake; the filtrate from the coal slime filter press 19 and the tailings filter press 20 is returned to the mixing tank 6 for recycling.

[0059] The inherent properties of coal gangue can be improved by changing the number of two-stage hydraulic cyclones 8, fine flotation machines 17, and scavenging flotation machines 18, thereby improving the separation quality of coarse coal slime, fine coal slime, and tailings slime.

[0060] This waste coal gangue re-sorting process includes seven steps: coal gangue crushing, classification and desliming, coarse coal slime heavy medium separation, coarse coal slime recovery, heavy medium recovery, fine coal slime flotation, and dewatering and recovery of fine coal slime and tailings slime. It employs a two-stage closed crushing and pulverizing system to crush the coal gangue to below 3.0 mm. The crushed coal gangue is mixed with water in a mixing tank 6 to form a coal slime solution of a certain concentration, which is then pumped into two-stage, series-connected hydrocyclones 8 for classification and desliming. The underflow from the second-stage hydrocyclone 8 enters the coarse coal slime tank 9 and is mixed with the heavy medium, then pumped into the coal slime heavy medium hydrocyclone 10 for separation. The overflow of the heavy medium hydrocyclone 10 enters the high frequency screen 11 for dewatering. The oversize material of the high frequency screen 11 enters the coal slime centrifugal dewatering machine 12 for further dewatering to become coarse and fine coal slime. The underflow of the coal slime containing heavy medium from the heavy medium hydrocyclone 10 and the undersize material from the high frequency screen 11 enter the magnetic separator 13 for heavy medium recovery. The concentrate from the magnetic separator 13 and the filtrate from the coal slime centrifugal dewatering machine 12 are sent together to the coarse coal slime tank 9 for recycling. The overflow of the first and second stage hydraulic classification hydrocyclones 8 and the tailings from the magnetic separator 13 enter the flotation operation together. After roughing, scavenging and cleaning three-stage flotation molds, they are separated into fine coal slime and tailings coal slime.

[0061] This invention discloses a waste coal gangue re-sorting process, which mainly includes three stages: coal gangue crushing, coarse particle heavy medium separation, and fine particle flotation. It effectively recovers coarse and fine-grained clean coal from the crushed coal gangue, greatly improving the clean coal recovery rate. Before separation, a two-stage closed crushing and pulverizing process is used to crush the coal gangue to below 3.0 mm to ensure the complete dissociation of fixed carbon embedded in the coal gangue. A two-stage hydraulic classifier is used to pre-classify and deslim the coal slurry, providing a suitable feed particle size for heavy medium separation and flotation, thus improving the separation efficiency and accuracy of heavy medium separation and flotation. The use of a coal slurry heavy medium cyclone separator is highly adaptable to coal slurry and can effectively separate difficult-to-separate coal slurry. The three-stage flotation mode of coarsening, scavenging, and cleaning maximizes the recovery rate of fine-grained coal slurry.

[0062] Waste coal gangue is separated into three products—coarse clean coal slime, fine clean coal slime, and tailings slime—using the separation process of this invention. The quality of the clean coal slime is related to the hydrocyclone classifier. When the heavy medium hydrocyclone is unavailable, the quality of the clean coal slime can be effectively improved by changing the number of hydrocyclones connected in series. Similarly, the quality of the fine clean coal slime and tailings slime can be improved by changing the number of cleaning and scavenging flotation machines. Therefore, this separation process is highly flexible.

[0063] In summary, this sorting process offers high sorting accuracy and overall recovery rate. It is highly adaptable to coal gangue and coal slime, effectively sorting difficult or extremely difficult coal slime. It effectively recovers useful components from both coarse and fine particles in crushed coal gangue, greatly improving the utilization rate of coal gangue. This process solves the technical problems of low sorting accuracy, poor adaptability, and inability to effectively sort difficult or extremely difficult coal slime in current coal gangue sorting processes. It enables the sorting and reuse of waste coal gangue while avoiding environmental pollution caused by large-scale coal gangue accumulation.

[0064] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them; when the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope claimed by the present invention.

Claims

1. A waste coal gangue re-sorting process, characterized in that, This includes coal gangue crushing, classification and desliming, coarse coal slime heavy medium separation, coarse coal slime recovery, heavy medium recovery, fine coal slime flotation, and dewatering of fine coal slime and tailings slime; S1: Coal gangue crushing: Carbon is embedded in coal gangue, and the coal gangue is crushed to a particle size of less than 3.0 mm. The crushing of coal gangue in S1 adopts a two-stage closed crushing method: the coal gangue first enters the coarse crusher, and after preliminary crushing, it enters the coarse crushing and grading screen. The material on the coarse crushing and grading screen is returned to the coarse crusher for re-crushing, and the material under the coarse crushing and grading screen enters the fine crusher for further crushing. After being crushed by the fine crusher, it enters the fine crushing and grading screen. The material on the fine crushing and grading screen is returned to the fine crusher for re-crushing, and the material under the fine crushing and grading screen enters the pulverizer to be crushed to a particle size of less than 3.0 mm. S2: Staged desliming: Coal gangue pulverized material with a particle size of less than 3.0 mm is mixed with water in a mixing tank to form coal slurry. The slurry is then pumped into a first-stage hydrocyclone for classification and desliming. After classification by the first-stage hydrocyclone, the underflow from the first-stage hydrocyclone enters a second-stage hydrocyclone for further classification. The underflow from the second-stage hydrocyclone, which contains coarse particles, enters the heavy medium separation operation, while the overflow from the first-stage and second-stage hydrocyclones, which contains fine particles, enters the flotation operation together. S3: Coarse coal slime heavy media separation: The underflow from the two-stage hydraulic classifier enters the coarse coal slime bucket and is mixed with the heavy medium. It is then pumped into the coal slime heavy medium hydrocyclone for separation. The overflow from the coal slime heavy medium hydrocyclone after separation is used for coarse coal slime recycling. S4: Coarse coal slime recovery: The overflow from the coal slime heavy medium hydrocyclone enters a high-frequency screen for dewatering. The material on the high-frequency screen then enters a coal slime centrifugal dewatering machine for further dewatering, becoming coarse and fine coal slime. S5: Heavy Media Recovery The underflow of the coal slime heavy medium hydrocyclone containing heavy medium and the underflow of the high frequency screen enter the magnetic separator for heavy medium recovery. After recovery, the concentrate of the magnetic separator and the filtrate of the coal slime centrifugal dewatering machine are sent together to the coarse coal slime bucket for recycling. S6: Fine coal slime flotation: The overflow from the first-stage and second-stage hydrocyclones, along with the tailings from the magnetic separator, enter the fine coal slime bucket. After being pumped into the slurry pre-processor and mixed evenly with flotation reagents, the slurry enters the roughing flotation machine for pre-separation. The overflow from the roughing flotation machine enters the cleaning flotation machine for further separation, the overflow from the cleaning flotation machine enters the next dewatering operation, and the underflow from the cleaning flotation machine returns to the roughing flotation machine for further separation. The underflow from the roughing flotation machine enters the scavenging flotation machine for further separation, the overflow from the scavenging flotation machine is returned to the cleaning flotation machine for further separation, and the underflow from the scavenging flotation machine enters the next dewatering operation. S7: Fine coal slime and tailings dewatering and recovery: The overflow from the fine flotation machine enters the coal slime filter press for dewatering and becomes fine coal slime filter cake; the underflow from the scavenging flotation machine enters the tailings filter press for dewatering and becomes tailings filter cake; the filtrate from the coal slime filter press and the tailings filter press is returned to the mixing tank for recycling.

Images