High-chlorine coal washing system and high-chlorine coal washing method

Abstract

The invention provides a high-chlorine coal washing system and a high-chlorine coal washing method, relates to the technical field of coal washing processing, and aims to solve the problem that chlorine elements in coal are difficult to remove at the front end of a boiler. The high-chlorine coal washing system comprises a raw coal crushing and screening device, a raw coal storage and leaching device, a coarse particle coal washing device and a fine particle coal washing device. The raw coal crushing and screening device is used for crushing raw coal, screening the raw coal into coarse particles and fine particles according to the particle size and conveying the coarse particles and the fine particles to different raw coal bins. The raw coal storage and leaching device comprises a plurality of raw coal bins, and water circulation mechanisms are arranged in the raw coal bins and used for supplying water to the raw coal bins. The coarse-particle coal washing device is used for screening coarse-particle low-chlorine clean coal from coarse-particle coal discharged from the raw coal bunker; and the fine-particle coal washing device is used for screening out flotation low-chlorine clean coal from fine-particle coal discharged from the raw coal bunker. The dechlorinating device can be used for dechlorinating coal before the coal enters a boiler for combustion.

Description

Technical Field

[0001] This invention relates to the field of coal washing and processing technology, and more specifically, to a high-chlorine coal washing system and a high-chlorine coal washing method. Background Technology

[0002] Chlorine is a common harmful element in coal. Chlorine-containing substances in coal are released as HCl, Cl2, and organochlorine compounds upon combustion. When the chlorine content in coal is too high, it can easily cause serious boiler fouling, coking, and corrosion during combustion, severely impacting the safe operation of power plants. my country's "Interim Measures for the Quality Management of Commercial Coal" requires that the chlorine content of commercial coal be below 0.3%. However, the Shaerhu coalfield in Hami, Xinjiang, is a marine sedimentary deposit with a high chlorine content, classifying it as high-chlorine coal (average 0.8%). Due to the harmful effects of chlorine, the development and utilization of this coalfield are restricted.

[0003] Leaching is a widely used process for dechlorination of fly ash, effectively removing chloride salts from waste incineration fly ash. The leaching process removes chlorine from fly ash essentially through a gas-solid acid-base neutralization reaction. Hydrogen chloride is a strongly acidic gas, and oxides, hydroxides, and their salts of alkali metals and alkaline earth metals have a strong affinity for it. Therefore, the active components of dechlorinating agents are mainly alkali metal and alkaline earth metal types. During dechlorination, 20-25 granular dechlorinating agents (approximately 5mm in length) are first loaded into the lower part of the dechlorination reactor in contact with the gas source, followed by 3-5 ml of 20-40 mesh granulated dechlorinating agent. However, this technology also dechlorinates flue gas after coal combustion, but cannot remove chlorine at the boiler front end. This inevitably leads to the release of chlorine from the coal during combustion, easily causing boiler fouling, coking, and corrosion problems, seriously affecting the safe and stable operation of coal-fired boilers. Summary of the Invention

[0004] The first objective of this invention is to provide a high-chlorine coal washing system to solve the technical problem that chlorine in existing coal is difficult to remove at the boiler front end.

[0005] The first aspect of this invention provides a high-chlorine coal washing system, comprising a raw coal crushing and screening device, a raw coal storage and leaching device, a coarse-particle coal washing device, and a fine-particle coal washing device; the raw coal crushing and screening device is used to crush the raw coal and screen it into coarse-particle coal and fine-particle coal according to the particle size and transport them to different raw coal bins; the raw coal storage and leaching device includes multiple raw coal bins, each raw coal bin is equipped with a water circulation mechanism for supplying water to the raw coal bins; the coarse-particle coal washing device is used to screen out coarse-particle low-chlorine clean coal from the coarse-particle coal discharged from the raw coal bins; the fine-particle coal washing device is used to screen out flotation low-chlorine clean coal from the fine-particle coal discharged from the raw coal bins.

[0006] The beneficial effects of the high-chlorine coal washing system of this invention are: By installing a water circulation mechanism in the raw coal bunker, coarse and fine coal particles can be immediately immersed in water after being separated, allowing the chlorine in the coal to be quickly released into the water or solution. At the same time, the ash content in the coal is reduced, increasing the economic value of coal resources. Thus, before entering the furnace, the chlorine in high-chlorine lump coal is effectively removed and the ash content of the raw coal is reduced, preventing corrosion of the boiler's heating surfaces and ensuring the safe and stable operation of the coal-fired boiler.

[0007] In an optional technical solution, the high-chlorine coal washing system further includes a slurry forming device, which is used to mix the coarse-particle low-chlorine clean coal, the flotation low-chlorine clean coal, and the dispersant.

[0008] In an optional technical solution, the high-chlorine coal washing system further includes an external discharge device. The coarse-particle coal washing device is also used to screen out coarse-particle tailings from the coarse-particle coal discharged from the raw coal bunker, and the fine-particle coal washing device is also used to float out flotation tailings from the fine-particle coal discharged from the raw coal bunker. The external discharge device is used to collect and transport the coarse-particle tailings and the flotation tailings to the gangue bunker.

[0009] In an optional technical solution, the raw coal bunker includes a bunker body and a water injection pipe. A first discharge port is opened at the bottom of the bunker body, and the first discharge port is connected to the coarse coal washing system and / or the fine coal washing system. A water injection port connected to the water injection pipe is opened in the middle of the bunker body.

[0010] In an optional technical solution, the coarse coal washing system includes a spiral separator for reducing ash and dechlorinating the coarse coal particles; the fine coal washing system includes a flotation machine for reducing ash and dechlorinating the fine coal particles.

[0011] The second objective of this invention is to provide a method for washing and beneficiating high-chlorine coal to solve the technical problem that chlorine in coal is difficult to remove at the boiler front end.

[0012] The second aspect of the present invention provides a method for washing and beneficiating high-chlorine coal, which includes the above-mentioned high-chlorine coal washing and beneficiation system.

[0013] The high-chlorine coal washing method uses any of the high-chlorine coal washing systems mentioned above.

[0014] By employing the aforementioned high-chlorine coal washing system in the high-chlorine coal washing method, the high-chlorine coal washing method accordingly possesses all the advantages of the aforementioned high-chlorine coal washing system, which will not be elaborated upon here.

[0015] In an optional technical solution, the high-chlorine coal washing method includes: the raw coal crushing and screening device crushes and classifies the raw coal into coarse particles and fine particles; the coarse particles are transported to a first raw coal bunker, and the fine particles are transported to a second raw coal bunker; water is injected into the first and second raw coal bunkers respectively; the coarse particles low-chlorine clean coal is screened from the coarse particles discharged from the first raw coal bunker using the coarse particles washing device; and the fine particles low-chlorine clean coal is screened from the fine particles discharged from the second raw coal bunker using the flotation device.

[0016] Among the optional technical solutions, the coal washing and beneficiation methods for high-chlorine coal also include: The coarse-grained low-chlorine clean coal, the flotation low-chlorine clean coal, water, and dispersant are mixed to prepare a low-ash, low-chlorine coal-water slurry. The water dispersant accounts for 0.5% to 2% of the total weight of the coarse-grained low-chlorine clean coal, the flotation low-chlorine clean coal, and the dispersant. The total weight of the coarse-grained low-chlorine clean coal, the flotation low-chlorine clean coal, and the dispersant accounts for 25% to 35% of the total mass of the low-ash, low-chlorine coal-water slurry.

[0017] In an optional technical solution, the coarse coal washing device further screens out coarse tailings from the coarse coal discharged from the raw coal bunker, and the fine coal washing device further floats out flotation tailings from the fine coal discharged from the raw coal bunker; the discharge device collects and transports the coarse tailings and the flotation tailings to the gangue bunker.

[0018] In an optional technical solution, water is injected into the first raw coal bunker and the second raw coal bunker respectively. In the first raw coal bunker and the second raw coal bunker, the ratio of coarse coal particles and fine coal particles to water is 2:8 to 1:10 respectively. The coarse coal particles and fine coal particles are soaked in water for 30 minutes to 40 minutes. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments or background art of the present invention, the drawings used in the description of the embodiments or background art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the high-chlorine coal washing system provided in Embodiment 1 of the present invention.

[0021] Figure 2 This is a schematic diagram of the raw coal silo in the high-chlorine coal washing system provided in Embodiment 1 of the present invention.

[0022] Figure 3 This is a schematic flowchart of the high-chlorine coal washing method provided in Embodiment 2 of the present invention.

[0023] Explanation of reference numerals in the attached figures: 110 - Raw coal crushing and screening device; 120 - Raw coal storage and leaching device; 130 - Coarse coal washing device; 140 - Fine coal washing device; 150 - Slurry forming device; 160 - Discharge device. Detailed Implementation

[0024] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0025] Example 1: Figure 1 This is a schematic diagram of the high-chlorine coal washing system provided in Embodiment 1 of the present invention. Figure 1 As shown, the high-chlorine coal washing system provided in Embodiment 1 of the present invention includes a raw coal crushing and screening device 110, a raw coal storage and leaching device 120, a coarse-particle coal washing device 130, and a fine-particle coal washing device 140. The raw coal crushing and screening device 110 is used to crush the raw coal and screen it into coarse-particle coal and fine-particle coal according to the particle size and transport them to different raw coal bins. The raw coal storage and leaching device 120 includes multiple raw coal bins, each equipped with a water circulation mechanism for supplying water to the raw coal bins. The coarse-particle coal washing device 130 is used to screen out coarse-particle low-chlorine clean coal from the coarse-particle coal discharged from the raw coal bins. The fine-particle coal washing device 140 is used to screen out flotation low-chlorine clean coal from the fine-particle coal discharged from the second raw coal bin.

[0026] By installing a water circulation mechanism in the raw coal bunker, coarse and fine coal particles can be immediately immersed in water after being separated, allowing the chlorine in the coal to be quickly released into the water or solution. At the same time, the ash content in the coal is reduced, increasing the economic value of coal resources. Thus, before entering the furnace, the chlorine in high-chlorine lump coal is effectively removed and the ash content of the raw coal is reduced, preventing corrosion of the boiler's heating surfaces and ensuring the safe and stable operation of the coal-fired boiler.

[0027] High-chlorine coal refers to coal with a chlorine content exceeding 0.3%, corresponding to coarse-grained low-chlorine clean coal and flotation low-chlorine clean coal. In this application, there can be two raw coal silos—a first raw coal silo and a second raw coal silo. The first raw coal silo is used to store coarse-grained coal, and the second raw coal silo is used to store fine-grained coal. In this embodiment, coarse-grained coal refers to coal with a size greater than 3 mm, and fine-grained coal refers to coal with a size less than 3 mm.

[0028] like Figure 1 As shown, optionally, the high-chlorine coal washing system also includes a slurry forming device 150, which is used to mix coarse-particle low-chlorine clean coal, flotation low-chlorine clean coal and dispersant.

[0029] By setting up a slurry forming device 150 to mix coarse-particle low-chlorine clean coal, flotation low-chlorine clean coal and dispersant into a low-ash, low-chlorine coal-water slurry, coal can be transported in a fluid manner, reducing dust pollution and coal loss during the transportation process.

[0030] In this embodiment, the slurry forming device 150 can be a ball mill. The ball mill can mix coarse low-chlorine clean coal, flotation low-chlorine clean coal and dispersant, so that they are fully mixed with water to prepare a low-ash and low-chlorine coal-water slurry.

[0031] like Figure 1 As shown, optionally, the high-chlorine coal washing system also includes an external discharge device 160. The coarse particle coal washing device 130 is also used to screen out coarse tailings from the coarse particles discharged from the raw coal bunker, and the fine particle coal washing device 140 is also used to float out flotation tailings from the fine particles discharged from the raw coal bunker. The external discharge device 160 is used to collect and transport the coarse tailings and flotation tailings to the gangue bunker.

[0032] By not directly utilizing coarse-grained tailings and flotation tailings, but instead transporting them to the gangue bin, they can be treated as waste along with the gangue. If gangue backfilling is required, the smaller size of the coarse-grained tailings and flotation tailings can be used to fill the gaps in the gangue, thereby reducing the deformation of the gangue after backfilling.

[0033] Specifically, the discharge device 160 includes a belt conveyor, which is used to transport coarse tailings and flotation tailings to the gangue bin.

[0034] Figure 2 This is a schematic diagram of the raw coal silo in the high-chlorine coal washing system provided in Embodiment 1 of the present invention. Figure 2 As shown, optionally, the raw coal bunker includes a bunker body and a water injection pipe. A first discharge port is opened at the bottom of the bunker body, and the first discharge port is connected to the coarse coal washing system and / or the fine coal washing system. A water injection port connected to the water injection pipe is opened in the middle of the bunker body.

[0035] By setting a first discharge port at the bottom of the silo body, the soaked coarse and fine coal particles can be directly discharged and sent to subsequent processing equipment. A water inlet is located in the middle of the silo body to soak most of the coarse or fine coal particles, thereby leaching out the chlorine from the coal.

[0036] Taking a cylindrical silo with a diameter of 10m and a height of 20m as an example, six water injection pipes, each with a diameter of 200mm, can be evenly spaced around the silo body. The water injection port on the silo body can be located in the middle of the silo body. The bottom of the water injection pipe connects to the bottom of the silo body, allowing water to enter from the bottom. A pump (not shown in the diagram) can pump the water from the bottom of the silo body upwards and then into the middle of the silo body, thus reusing the water at the bottom and reducing water consumption. Alternatively, the top of the water injection pipe can be connected to an external water source to supply fresh water to the silo body for soaking coarse or fine coal particles.

[0037] like Figure 1 As shown, optionally, the coarse coal washing system includes a spiral separator for reducing ash and dechlorinating coarse coal particles; the fine coal washing system includes a flotation machine for reducing ash and dechlorinating fine coal particles.

[0038] Spiral separators can not only separate coarse low-chlorine clean coal from coarse tailings using gravity, but also reduce ash and dechlorinate coarse coal particles. Flotation machines, on the other hand, can separate low-chlorine clean coal and tailings by utilizing the difference in surface hydrophilicity.

[0039] Example 2: Example 2 also provides a method for washing high-chlorine coal, including the above-mentioned high-chlorine coal washing system.

[0040] The high-chlorine coal washing method uses any of the high-chlorine coal washing systems mentioned above.

[0041] By incorporating the aforementioned high-chlorine coal washing system into the high-chlorine coal washing method, the high-chlorine coal washing method possesses all the advantages of the aforementioned high-chlorine coal washing system, which will not be elaborated upon here.

[0042] Figure 3 This is a schematic flowchart of the high-chlorine coal washing method provided in Embodiment 2 of the present invention. Figure 3As shown, optionally, the high-chlorine coal washing method includes: the raw coal crushing and screening device 110 crushes and classifies the raw coal into coarse particles and fine particles; the coarse particles are transported to the first raw coal bunker, and the fine particles are transported to the second raw coal bunker; water is injected into the first and second raw coal bunkers respectively; the coarse particle coal washing device 130 screens out coarse low-chlorine clean coal from the coarse particles discharged from the first raw coal bunker; and the fine particle coal washing device 140 screens out flotation low-chlorine clean coal from the fine particles discharged from the raw coal bunker.

[0043] Soaking coarse coal particles in the first raw coal bunker and fine coal particles in the second raw coal bunker allows for the rapid release of chlorine from the coal into water or solution. This also reduces the ash content of the coal, increasing the economic value of coal resources. Thus, before the coal is fed into the furnace, chlorine is effectively removed from high-chlorine lump coal, and the ash content of the raw coal is reduced, preventing corrosion of the boiler's heating surfaces and ensuring the safe and stable operation of the coal-fired boiler.

[0044] Specifically, in the crushing and grading of raw coal, two-stage crushing and two-stage screening can be carried out. Crushing involves breaking all the raw coal to below 10mm, while screening can separate the crushed raw coal into two grades: 0mm~3mm and 3mm~10mm. That is, coarse coal particles are 3mm~10mm, while fine coal particles are 0mm~3mm.

[0045] Alternatively, the coal washing method for high-chlorine coal also includes: A low-ash, low-chlorine coal slurry is prepared by mixing coarse-grained low-chlorine clean coal, flotation low-chlorine clean coal, water, and a dispersant. The water and dispersant account for 0.5% to 2% of the total weight of the coarse-grained low-chlorine clean coal, flotation low-chlorine clean coal, and dispersant. The total weight of the coarse-grained low-chlorine clean coal, flotation low-chlorine clean coal, and dispersant accounts for 25% to 35% of the total mass of the low-ash, low-chlorine coal slurry.

[0046] Mixing coarse-grained low-chlorine clean coal, flotation-selected low-chlorine clean coal, and a dispersant to form a low-ash, low-chlorine coal-water slurry allows for fluid transport of coal, reducing dust pollution and coal loss during transport. Furthermore, after the coarse-grained coal washing unit 130 washes out coarse-grained low-chlorine clean coal and the fine-grained coal washing unit 140 washes out fine-grained low-chlorine clean coal, these two particles are mixed with a dispersant and water, directly producing the coal-water slurry without dehydration. This reduces process steps and improves processing efficiency. Additionally, the moisture adhering to the surfaces of the coarse and fine low-chlorine clean coal reduces the total amount of water added during mixing, thereby lowering the total material input and production costs.

[0047] Specifically, in this embodiment, the dispersant can be sodium lignosulfonate or other sodium-containing dispersants. The weight ratio of coarse low-chlorine clean coal to flotation low-chlorine clean coal can be 1:5 to 1:1, preferably 1:4. During the mixing process, the material can be ground in a ball mill for 20 to 30 minutes to a particle size of 0.045 mm to facilitate water transport.

[0048] like Figure 3 As shown, optionally, the coarse coal washing device 130 also screens out coarse tailings from the coarse coal discharged from the raw coal bunker, and the fine coal washing device 140 also floats out flotation tailings from the fine coal discharged from the raw coal bunker; the discharge device 160 collects the coarse tailings and flotation tailings and transports them to the gangue bunker.

[0049] By not directly utilizing coarse-grained tailings and flotation tailings, but instead transporting them to the gangue bin, they can be treated as waste along with the gangue. If gangue backfilling is required, the smaller size of the coarse-grained tailings and flotation tailings can be used to fill the gaps in the gangue, thereby reducing the deformation of the gangue after backfilling.

[0050] Among them, the spiral separator can separate coarse-grained low-chlorine clean coal and coarse-grained tailings by utilizing the difference in density. For example, the density threshold can be selected as 1.6 kJ / cm³. 3 .

[0051] Optionally, water is injected into the first and second raw coal bunkers respectively, and the ratio of coarse coal particles to water in the first and second raw coal bunkers is 2:8 to 1:10 respectively; the coarse coal particles and fine coal particles are soaked in water for 30 to 40 minutes.

[0052] Taking a cylindrical silo with a diameter of 10m and a height of approximately 20m as an example, six water injection pipes are evenly spaced along the circumference of each silo. Each water injection pipe can inject 200m³ of water into the silo. 3 / h, while in the main body of the silo, the ratio of coal to water can be 1:9 to 1:11, and the coal can be soaked in water for 30 to 40 minutes and rinsed by circulating water about 5 to 8 times.

[0053] like Figure 3 As shown in the figure, the coal washing method for high-chlorine coal provided in this embodiment includes: The raw coal crushing and screening device 110 crushes and classifies the raw coal into coarse coal particles and fine coal particles. The coarse coal particles are transported to the first raw coal bunker, and the fine coal particles are transported to the second raw coal bunker.

[0054] Water was injected into the first and second raw coal bunkers respectively.

[0055] The coarse-particle coal washing device 130 is used to screen out coarse-particle low-chlorine clean coal and coarse-particle tailings from the coarse-particle coal discharged from the first raw coal bunker; the fine-particle coal washing device 140 is used to screen out flotation low-chlorine clean coal and flotation tailings from the fine-particle coal discharged from the second raw coal bunker.

[0056] The coarse-particle low-chlorine clean coal, flotation low-chlorine clean coal, water and dispersant are mixed using a slurry forming device 150 to prepare a low-ash, low-chlorine coal-water slurry.

[0057] The coarse tailings and flotation tailings are transported to the gangue bin using the external discharge device 160.

[0058] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

[0059] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the term "comprising" or any other variations thereof is intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0060] In the above embodiments, descriptions of directions such as "up" and "down" are based on the accompanying drawings.

[0061] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention.

[0062] Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A high-chlorine coal washing and beneficiation system, characterized in that, The system includes a raw coal crushing and screening device (110), a raw coal storage and leaching device (120), a coarse coal washing and beneficiation device (130), and a fine coal washing and beneficiation device (140). The raw coal crushing and screening device (110) is used to crush raw coal and screen it into coarse and fine coal particles according to their particle size, and transport them to different raw coal silos. The raw coal storage and leaching device (120) includes multiple raw coal silos, each of which is equipped with a water circulation mechanism for supplying water to the raw coal silos. The coarse coal washing and beneficiation device (130) is used to screen out coarse low-chlorine clean coal from the coarse coal particles discharged from the raw coal silos. The fine coal washing and beneficiation device (140) is used to screen out flotation low-chlorine clean coal from the fine coal particles discharged from the raw coal silos.

2. The high-chlorine coal washing system according to claim 1, characterized in that, The high-chlorine coal washing system also includes a slurry forming device (150) for mixing the coarse-particle low-chlorine clean coal, the flotation low-chlorine clean coal, and the dispersant.

3. The high-chlorine coal washing system according to claim 1, characterized in that, The high-chlorine coal washing system also includes an external discharge device (160). The coarse particle coal washing device (130) is also used to screen out coarse tailings from the coarse particles discharged from the raw coal bunker. The fine particle coal washing device (140) is also used to float out flotation tailings from the fine particles discharged from the raw coal bunker. The external discharge device (160) is used to collect the coarse tailings and the flotation tailings and transport them to the gangue bunker.

4. The high-chlorine coal washing system according to claim 1, characterized in that, The raw coal bunker includes a bunker body and a water injection pipe. A first discharge port is opened at the bottom of the bunker body, and the first discharge port is connected to the coarse coal washing system and / or the fine coal washing system. A water injection port connected to the water injection pipe is opened in the middle of the bunker body.

5. The high-chlorine coal washing system according to claim 1, characterized in that, The coarse-particle coal washing system includes a spiral separator for reducing ash and dechlorinating the coarse-particle coal; the fine-particle coal washing system includes a flotation machine for reducing ash and dechlorinating the fine-particle coal.

6. A method for washing and beneficiating high-chlorine coal, characterized in that, The high-chlorine coal washing method uses the high-chlorine coal washing system of any one of claims 1-5.

7. The method for washing and beneficiating high-chlorine coal according to claim 6, characterized in that, include: The raw coal crushing and screening device (110) crushes and classifies the raw coal into coarse coal particles and fine coal particles. The coarse coal particles are transported to the first raw coal bunker, and the fine coal particles are transported to the second raw coal bunker. Water is injected into the first and second raw coal bunkers respectively. The coarse coal washing device (130) screens out the coarse low-chlorine clean coal particles from the coarse coal particles discharged from the first raw coal bunker. The fine coal washing device (140) screens out the flotation low-chlorine clean coal particles from the fine coal particles discharged from the second raw coal bunker.

8. The method for washing and beneficiating high-chlorine coal according to claim 7, characterized in that, Also includes: The coarse-grained low-chlorine clean coal, the flotation low-chlorine clean coal, water, and a dispersant are mixed to prepare a low-ash, low-chlorine coal-water slurry. The water dispersant accounts for 0.5% to 2% of the total weight of the coarse-grained low-chlorine clean coal, the flotation low-chlorine clean coal, and the dispersant. The total weight of the coarse-grained low-chlorine clean coal, the flotation low-chlorine clean coal, and the dispersant accounts for 25% to 35% of the total mass of the low-ash, low-chlorine coal-water slurry.

9. The method for washing and beneficiating high-chlorine coal according to claim 7, characterized in that, The coarse coal washing device (130) also screens out coarse tailings from the coarse coal discharged from the raw coal bunker, and the fine coal washing device (140) also floats out flotation tailings from the fine coal discharged from the raw coal bunker; the discharge device (160) collects and transports the coarse tailings and the flotation tailings to the gangue bunker.

10. The method for washing and beneficiating high-chlorine coal according to claim 7, characterized in that, Water is injected into the first and second raw coal bunkers respectively. In the first and second raw coal bunkers, the ratio of coarse coal particles to water is 2:8 to 1:

10. The coarse coal particles and fine coal particles are soaked in water for 30 to 40 minutes.

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