System and method for preparing high-concentration coal water slurry by mixing and dewatering coarse and fine coal

Abstract

The application discloses a system and method for preparing high-concentration coal water slurry by mixing and dehydrating coarse and fine coal of pipe-conveyed coal slurry, comprising a coal slurry storage system, a coal slurry dehydration system, a coal slurry fine grinding system, a coal slurry kneading and mixing system, a dehydrated coal conveying system, an additive supply system and a process water supply system; the pipe-conveyed coal slurry is mixed with coal powder, which is all from the product of pipe-conveyed coal slurry dehydration; part of the pipe-conveyed coal slurry is dehydrated to prepare coarse and fine particle size dehydrated coal, and another part of the pipe-conveyed coal slurry is finely ground and mixed with the coarse and fine particle size dehydrated coal in a certain proportion to prepare high-concentration coal water slurry; the high-concentration coal water slurry product can be transported by pipeline or tank car to supply short-distance chemical users, and the system realizes the mode of slurry preparation, slurry use and one-to-many.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of coal water slurry preparation device, and particularly relates to a system for preparing high-concentration coal water slurry by mixing and dewatering coarse and fine coal, and a method for preparing high-concentration coal water slurry by mixing and dewatering coarse and fine coal. BACKGROUND

[0002] Currently, the users of coal water slurry gasification all adopt the one-time slurry preparation process of “pulverized coal dry crushing + wet grinding” or the multi-stage slurry preparation process of “dry crushing + classified grinding / reshaping grinding + shearing stirring” to realize the point-to-point preparation of high-concentration coal water slurry from raw coal to coal water slurry to meet the gasification demand, and the general concentration is 60-63%. However, there are disadvantages such as high matching degree requirement of raw materials and slurry preparation process, low product concentration, unreasonable particle size gradation, high viscosity, and limited layout distance of raw coal-slurry preparation-slurry use, which leads to low gasification efficiency, low effective gas yield, high specific coal consumption, high specific oxygen consumption, high CO2 emission, and the need for the user of slurry to have production systems of coal transportation, coal storage and slurry preparation at the same time.

[0003] The Shengwei Pipe Transportation Company adopts the two-stage slurry preparation method of “raw coal-conventional concentration coal water slurry-high concentration coal water slurry”. The conventional concentration coal water slurry is formed by dry crushing and wet grinding of raw coal, and is suitable for long-distance and large-diameter pipeline transportation due to its single-peak particle size gradation. According to the method for preparing gasification coal slurry from long-distance coal water slurry disclosed in “CN 115554908 A”, the medium-concentration coal water slurry with single-peak gradation is prepared into high-concentration coal water slurry with three-peak gradation through processes such as dewatering, two-stage concentration, dewatering, fine grinding, superfine grinding and kneading, and is delivered to the chemical user through the pipeline, which improves the concentration of the conventional concentration coal water slurry, reduces the average particle size, and meets the demand of the chemical user. However, this method has disadvantages such as complex thickening and slurry preparation process, high energy consumption, small consumption of dewatered coal, and unsatisfactory economic benefits.

[0004] CN 106987290 B discloses a method for thickening coal water slurry, that is, part of the pipeline transportation coal water slurry is finely ground with water and additives, part of the pipeline transportation coal water slurry is superfine ground with water and additives, the remaining pipeline transportation coal water slurry is mixed with part of the slurry formed by fine grinding and superfine grinding, raw coal, water and additives, and wet grinding, and the remaining slurry formed by fine grinding and superfine grinding is mixed with the coal slurry obtained by wet grinding to prepare high-concentration coal water slurry. However, this method has disadvantages such as complex process, and the need for mixing raw coal, fine grinding and superfine grinding with large energy consumption.

[0005] The current raw coal is transported by long-distance pipeline, which has become an unstoppable new logistics mode. Due to the limitation of pipeline transportation concentration and viscosity, the concentration of coal slurry transported by pipeline is generally conventional concentration. If the conventional concentration of coal slurry transported by pipeline is used as raw material, the following conditions need to be met: meeting the user's slurry demand, while meeting the preparation and switching of high-concentration coal water slurry and dewatered coal; simplifying the thickening and slurry preparation process, saving energy consumption; according to the transportation distance of chemical users, the layout of the original slurry preparation system, selecting pipeline slurry or 'carrying coal + wet slurry', realizing the slurry preparation-slurry use 'one-to-many' mode, saving the one-time investment cost of the slurry preparation device and the production cost, and solving the problem of single and limited transportation mode of high-concentration coal water slurry. SUMMARY

[0006] The purpose of the present application is to provide a system for preparing high-concentration coal water slurry by mixing and dewatering coarse and fine coal with pipeline coal slurry, which solves the problems of complex thickening and slurry preparation process and poor economic benefits in the existing high-concentration coal water slurry preparation process.

[0007] The purpose of the present application is to provide a system for preparing high-concentration coal water slurry by mixing and dewatering coarse and fine coal with pipeline coal slurry, which solves the problems of complex thickening and slurry preparation process and poor economic benefits in the existing high-concentration coal water slurry preparation process.

[0008] The technical scheme adopted by the present application is: a system for preparing high-concentration coal water slurry by mixing and dewatering coarse and fine coal with pipeline coal slurry, which comprises a coal slurry storage system, a coal slurry dewatering system, a coal slurry fine grinding system, a coal slurry kneading system, a dewatered coal conveying system, and an additive supply system. The pipeline coal slurry is mixed with dewatered coal powder, which is the product of pipeline coal slurry dewatering, to realize the slurry preparation, slurry use, and one-to-many mode.

[0009] The present application also has the following characteristics:

[0010] The coal slurry buffer tank outlet is connected to the inlet of the feed pump through a pipeline. The outlet of the feed pump is divided into two branch pipelines. One of the branch pipelines is connected to the inlet of the coarse coal dewatering machine. The coarse coal dewatering machine is directly below the coarse coal dewatering machine discharge port. The coarse coal dewatering machine discharge port is connected to the coarse coal conveying belt and the coarse coal kneading machine inlet. The coarse coal kneading machine outlet is connected to the finished slurry tank inlet through a pipeline. The coarse coal dewatering machine liquid discharge end is connected to the dilute liquid tank inlet through a pipeline. The dilute liquid tank outlet is connected to the thickening tank through a pipeline. The overflow of the thickening tank is discharged as coal slurry water, which is collected through a pipeline and discharged into the water treatment system. The coal slurry at the bottom of the thickening tank is transported into the fine coal dewatering machine by the underflow pump. The fine coal dewatering machine discharge port is directly below the fine coal dewatering belt. The fine coal dewatering belt discharge port is connected to the fine coal conveying belt and the screw material receiving bin inlet. The screw material receiving bin discharge port is connected to the fine coal kneading machine inlet through a pipeline. The fine coal kneading machine discharge port is connected to the kneading tank inlet through a pipeline. The kneading tank outlet is connected to the kneading pump through a pipeline. The kneading pump outlet is connected to the coarse coal kneading machine inlet.

[0011] The other branch pipeline of the feed pump is connected with the inlet of the fine coal kneader; the outlet of the additive buffer tank is connected with the inlet of the additive pump through a pipeline, and the outlet of the additive pump is divided into two branch pipelines, one of which is connected with the coarse coal kneader, and the other is connected with the fine coal kneader.

[0012] The main pipeline after the feed pump is provided with a total valve XV01, and the two branch pipelines are respectively provided with a flow regulating valve FV01 and a flow meter FT01, a flow regulating valve FV02 and a flow meter FT02.

[0013] The dewatered coarse coal scraper is provided with two discharge openings respectively leading to the coarse coal outward conveying belt and the coarse coal kneader, and the amount of the dewatered coarse coal for outward conveying and blending can be adjusted by adjusting the size of the discharge openings;

[0014] The dewatered fine coal belt is provided with two discharge openings respectively leading to the fine coal outward conveying belt and the screw receiving bin, and the amount of the dewatered fine coal for outward conveying and blending can be adjusted by adjusting the size of the discharge openings.

[0015] The production water supply system is further included.

[0016] The outlet of the coal slurry buffer tank is connected with the inlet of the feed pump through a pipeline, and the outlet of the feed pump is divided into two branch pipelines, one of which is connected with the inlet of the coarse coal dewatering machine, the discharge opening of the coarse coal dewatering machine is directly below the dewatered coarse coal scraper, one of the discharge openings of the dewatered coarse coal scraper is connected with the coarse coal outward conveying belt, and the other is connected with the inlet of the coarse coal kneader, the outlet of the coarse coal kneader is connected with the inlet of the finished slurry tank through a pipeline; the liquid outlet of the coarse coal dewatering machine is connected with the inlet of the dilute liquid tank through a pipeline, the outlet of the dilute liquid tank is connected with the thickening pool through a pipeline, the overflow of the thickening pool is discharged as sludge water, which is collected through a pipeline and discharged into the water treatment system, and the sludge at the bottom of the thickening pool is transported into the fine coal dewatering machine by a bottom flow pump, the discharge opening of the fine coal dewatering machine is directly below the dewatered fine coal belt, one of the discharge openings of the dewatered fine coal belt is connected with the fine coal outward conveying belt, and the other is connected with the inlet of the screw receiving bin, the outlet of the screw receiving bin is connected with the inlet of the fine coal kneader through a pipeline, the outlet of the fine coal kneader is connected with the inlet of the kneading tank through a pipeline, the outlet of the kneading tank is connected with the inlet of the kneading pump through a pipeline, and the outlet of the kneading pump is connected with the inlet of the coarse coal kneader;

[0017] The other branch pipeline of the feed pump is connected with the inlet of the coarse slurry tank, the outlet of the coarse slurry tank is connected with the inlet of the coarse slurry pump through a pipeline, the outlet of the coarse slurry pump is connected with the inlet of the fine grinder through a pipeline, the outlet of the fine grinder is connected with the inlet of the fine slurry tank through a pipeline, the outlet of the fine slurry tank is connected with the inlet of the fine slurry pump through a pipeline, the outlet of the fine slurry pump is connected with the inlet of the fine coal kneader through a pipeline; the outlet of the additive buffer tank is connected with the inlet of the additive pump through a pipeline, the outlet of the additive pump is divided into two branch pipelines, one of which is connected with the coarse coal kneader, and the other is connected with the inlet of the coarse slurry tank; the outlet of the production water buffer tank is connected with the inlet of the production water pump, and the outlet of the production water pump is connected with the inlet of the coarse slurry tank through a pipeline.

[0018] The second technical solution adopted by the present application is a method for preparing high-concentration coal water slurry by mixing and dewatering coarse and fine coal, and the specific operation steps are as follows:

[0019] Step 1, open the total valve XV01 and the flow regulating valve FV01, continuously stir the pipe-conveyed coal slurry stored in the coal slurry buffer tank, and transport it to the coarse coal dewatering machine for dewatering, and the flow regulating valve FV01 and the flow meter FT01 control and measure the dewatering flow;

[0020] Step 2, after dewatering by the coarse coal dewatering machine, dilute liquid and dewatered coarse coal are produced, wherein the dilute liquid is collected in the dilute liquid tank for stirring and storage, and the dewatered coarse coal falls onto the dewatered coarse coal scraper below the discharge port of the coarse coal dewatering machine, and then falls into the coarse coal external conveying belt and the coarse coal kneading machine through the discharge port, and is transported into the coal storage bin through the coarse coal external conveying belt for storage and external sale;

[0021] Step 3, the dilute liquid in the dilute liquid tank is transported to the concentration tank through the pipeline and the pump for concentration and precipitation, wherein the supernatant is overflowed into the water treatment system for deep treatment and discharge, and the concentrated underflow is transported to the fine coal dewatering machine through the underflow pump for dewatering;

[0022] Step 4, the dewatered fine coal produced by the fine coal dewatering machine falls onto the dewatered fine coal belt directly below, and then falls into the fine coal external conveying belt and the spiral receiving bin through the discharge port, and is transported into the coal storage bin through the fine coal external conveying belt for storage and external sale;

[0023] Step 5, open the flow regulating valve FV02, and the pipe-conveyed coal slurry is transported into the fine coal kneading machine through another branch pipeline after the feed pump, and the flow regulating valve FV02 and the flow meter FT02 control and adjust the flow of the pipe-conveyed coal slurry into the fine coal kneading machine, that is, control the mixing ratio of the pipe-conveyed coal slurry;

[0024] Step 6, the dewatered fine coal is buffered and stirred in the spiral receiving bin, and is transported to the fine coal kneading machine through the pipeline, and is strongly kneaded with the pipe-conveyed coal slurry transported through another branch pipeline after the feed pump and the additive solution transported by the additive pump to form dewatered fine slurry;

[0025] Step 7, after the dewatered fine slurry is kneaded in the fine coal kneading machine, it is transported into the kneading tank through the pipeline for buffering and stirring again, and is then transported into the kneading pump through the bottom discharge pipeline;

[0026] Step 8, the dewatered fine slurry is transported into the coarse coal kneading machine through the kneading pump, and is strongly kneaded with the dewatered coarse coal falling into the coarse coal kneading machine through the dewatered coarse coal scraper and the additive solution transported by the additive pump to form high-concentration coal water slurry, which is transported into the finished slurry tank for buffering according to the distance and requirements of the user for pipeline or tank truck transportation;

[0027] The pipe-conveyed coal slurry is dehydrated to form dehydrated coarse coal and dehydrated fine coal, the pipe-conveyed coal slurry, the dehydrated fine coal and an additive are kneaded and mixed to form dehydrated fine slurry, and the dehydrated fine slurry, the dehydrated coarse coal and an additive are kneaded and mixed to form high-concentration coal water slurry;

[0028] The ratio of the pipe-conveyed coal slurry, the dehydrated coarse coal and the dehydrated fine coal is:

[0029]

[0030]

[0031]

[0032] The concentration of the dehydrated fine slurry is:

[0033]

[0034] The concentration of the high-concentration coal water slurry is:

[0035]

[0036] The ash content of the high-concentration coal water slurry is:

[0037]

[0038] The particle size grading of the high-concentration coal water slurry is:

[0039]

[0040] The total amount of the additive (the ratio of the total coal amount) is:

[0041]

[0042] Among them, , The particle sizes of the pipe-conveyed coal slurry, the dehydrated coarse coal and the dehydrated fine coal are respectively; i Indicates the grade, and is 1-5; The +14 mesh oversize is the ratio; The +48 mesh oversize is the ratio; The +200 mesh oversize is the ratio; The +325 mesh oversize is the ratio; The -325 mesh undersize is the ratio; , , The sum of the particle sizes is 100;

[0043] Table 1 Particle size grading of raw materials, intermediate products and final products

[0044]

[0045] The additive dry powder accounts for a percentage of the total coal amount;

[0046]

[0047] wherein, C 1 is the pipe conveying coal slurry concentration, C 2 is the dewatering fine coal concentration, C 3 is the high-concentration coal water slurry concentration, C 4 is the additive solution concentration; is the pipe conveying coal slurry density; Q1 is the total flow of the pipe conveying coal slurry; is the pipe conveying coal slurry ash content, is the dewatering coarse coal ash content, is the dewatering fine coal ash content, is the flow of the pipe conveying coal slurry into the dewatering system, is the flow of the pipe conveying coal slurry into the fine coal kneader, is the total flow of the additive solution, is the flow of the additive solution into the fine coal kneader, is the flow of the additive solution into the coarse coal kneader, is the moisture content of the dewatering coarse coal, is the moisture content of the dewatering fine coal, is the flow of the dewatering coarse coal, is the flow of the dewatering fine coal, The additive dry powder accounts for a percentage of the total coal amount.

[0048] Another method for preparing high-concentration coal water slurry by mixing and dewatering coarse and fine coal in the pipe conveying coal slurry according to the present application is as follows:

[0049] Step 1, open the total valve XV01 and the flow regulating valve FV01, the pipe conveying coal slurry is stored in the coal slurry buffer tank and continuously stirred, is transported to the coarse coal dewatering machine by the feeding pump for dewatering, and the flow regulating valve FV01 and the flow meter FT01 control and measure the dewatering flow;

[0050] Step 2, after the coarse coal dewatering machine is dewatered, dilute liquid and dewatering coarse coal are generated, wherein the dilute liquid is collected into the dilute liquid tank through a pipeline for stirring and storage, the dewatering coarse coal falls onto the dewatering coarse coal scraper below the discharge port of the coarse coal dewatering machine, and then falls into the coarse coal external conveying belt and the coarse coal kneader through the discharge port, and is transported into the coal storage bin by the coarse coal external conveying belt for storage and external sale;

[0051] Step 3, the dilute liquid in the dilute liquid tank is transported to the concentration tank through a pipeline and a pump for concentration and precipitation, wherein the supernatant is collected into the water treatment system through overflow for deep treatment and discharge, and the concentrated underflow is transported to the fine coal dewatering machine through an underflow pump for dewatering;

[0052] Step 4, the fine coal dewatering machine dewatering produces fine coal falling into the dewatering fine coal belt below, and then falling into the fine coal external conveying belt and the screw receiving bin through the dropping opening, and being conveyed into the coal storage bin through the fine coal external conveying belt for storage and external sale;

[0053] Step 5, the flow regulating valve FV02 is opened, the pipe conveying coal slurry is conveyed into the coarse slurry tank through another branch line after the inlet pump, and the flow regulating valve FV02 and the flow meter FT02 control and regulate the pipe conveying coal slurry flow into the coarse slurry tank, that is, control the proportion of the pipe conveying coal slurry for fine slurry preparation by fine grinding;

[0054] Step 6, the additive solution is stored in the additive buffer tank and stirred uniformly, and is conveyed into the coarse slurry tank and the coarse coal kneading machine through two branch lines through the additive pump, for reducing the viscosity of the pipe conveying coal slurry into the coarse slurry tank and the high-concentration coal water slurry into the coarse coal kneading machine;

[0055] Step 7, the production water is stored in the production water buffer tank and is conveyed into the coarse slurry tank through the production water pump, for diluting the pipe conveying coal slurry into the coarse slurry tank;

[0056] Step 8, the pipe conveying coal slurry in the coarse slurry tank is diluted and viscosity-reduced, and is conveyed into the fine grinder through the coarse slurry pump for fine grinding, so as to reduce the particle size of the pipe conveying coal slurry to form fine slurry;

[0057] Step 9, the fine slurry grinded by the fine grinder is conveyed into the fine slurry tank through the pipeline for buffering and stirring, and is conveyed into the fine coal kneading machine through the fine slurry pump, and the fine slurry pump is provided with the flow regulating valve FV03 and the flow meter FT03 after the fine slurry pump, so as to control and adjust the fine slurry flow into the fine coal kneading machine, thereby adjusting the mixing proportion of the fine slurry grinded by the pipe conveying coal slurry;

[0058] Step 10, the dewatered fine coal is buffered and stirred in the screw receiving bin, and is conveyed into the fine coal kneading machine through the pipeline, and is strongly kneaded with the fine slurry conveyed through the fine slurry pump to form dewatered fine slurry;

[0059] Step 11, the dewatered fine slurry is conveyed into the fine coal kneading machine after being kneaded in the fine coal kneading machine, is buffered and stirred uniformly again through the pipeline, and is discharged through the bottom discharge pipeline into the kneading pump;

[0060] Step 12, the dewatered fine slurry is conveyed into the coarse coal kneading machine through the kneading pump, is strongly kneaded with the dewatered coarse coal falling into the coarse coal kneading machine through the dewatered coarse coal scraper and the additive solution conveyed through the additive pump to form high-concentration coal water slurry, is conveyed into the finished slurry tank through the pipeline for buffering, and is transported through the pipeline or tank truck according to the distance and requirements of the user;

[0061] The pipe conveying coal slurry is dewatered to form dewatered coarse coal and dewatered fine coal, the pipe conveying coal slurry, the dewatered fine coal and the additive are kneaded and viscosity-reduced to form dewatered fine slurry, and the dewatered fine slurry, the dewatered coarse coal and the additive are kneaded to form high-concentration coal water slurry;

[0062] Pipe coal slurry: ratio of dewatered coarse coal: dewatered fine coal

[0063]

[0064]

[0065]

[0066]

[0067] Dewatered fine slurry concentration:

[0068]

[0069] Fine grinding concentration of pipe coal slurry:

[0070]

[0071] High concentration coal water slurry concentration:

[0072]

[0073] High concentration coal water slurry ash content:

[0074]

[0075] High concentration coal water slurry particle size distribution:

[0076]

[0077] wherein, , Particle size of pipe coal slurry, dewatered coarse coal, and dewatered fine coal, respectively; i Indicates the grade, taking 1-5; +14 mesh sieve is the ratio of oversize; +48 mesh sieve is the ratio of oversize; +200 mesh sieve is the ratio of oversize; +325 mesh sieve is the ratio of oversize; -325 mesh sieve is the ratio of undersize; , , The sum of the particle sizes is 100;

[0078] Particle size distribution of intermediate products and final products in Table 2

[0079]

[0080] The percentage of the amount of additive dry powder to the total amount of coal:

[0081]

[0082] wherein, C 1 is the concentration of pipe conveying coal slurry, C 2 is the concentration of dewatered fine coal slurry, C 3 is the concentration of high-concentration coal water slurry, C 4 is the concentration of additive solution, C 9 is the concentration of fine coal slurry; is the density of pipe conveying coal slurry; Q1 is the total flow of pipe conveying coal slurry; is the ash content of pipe conveying coal slurry, is the ash content of dewatered coarse coal, is the ash content of dewatered fine coal, is the flow of pipe conveying coal slurry into the dewatering system, is the flow of pipe conveying coal slurry into the fine coal kneader, is the total flow of additive solution, is the flow of additive solution into the coarse coal tank, is the flow of additive solution into the coarse coal kneader, is the flow of fine coal slurry, is the flow of production water; is the moisture content of dewatered coarse coal, is the moisture content of dewatered fine coal, is the flow of dewatered coarse coal, is the flow of dewatered fine coal, is the percentage of additive dry powder in the total amount of coal.

[0083] The additive dry powder includes a compound of naphthalene series and lignin sulfonate or a single substance, and the additive solution is a solution with a mass concentration of 10% prepared by adding water to the additive dry powder.

[0084] The beneficial effects of the present application are:

[0085] (1) Part of the pipe conveying coal slurry is dewatered to prepare coarse and fine particle size dewatered coal, and another part of the pipe conveying coal slurry is mixed with coarse and fine particle size dewatered coal in proportion, kneaded, and prepared into high-concentration coal water slurry, which can be transported by pipeline or tank car to supply different distances of chemical users.

[0086] (2) Part of the pipe conveying coal slurry is dewatered to prepare coarse and fine particle size dewatered coal, and another part of the pipe conveying coal slurry is finely ground and mixed with coarse and fine particle size dewatered coal in proportion, kneaded, and prepared into high-concentration coal water slurry, which can be transported by pipeline or tank car to supply short-distance chemical users.

[0087] (3) Different mixing and slurry concentration processes and product transportation methods can be selected according to the distribution distance of chemical users, especially the pipeline slurry supply method for short-distance chemical users, which has the advantages of convenience, high efficiency, cleanliness, economy, safety, stability, and large transportation capacity.

[0088] (4) Realize the pulp supply "one to many" goal, one pulp, many pulp, simplify the user production process, save the pulp device investment cost and production cost.

[0089] (5) The problem of limited application of pipe coal slurry is solved, the user market of conventional concentration pipe coal slurry is enriched, and the development of the pipeline coal industry is promoted. BRIEF DESCRIPTION OF DRAWINGS

[0090] Figure 1 is a schematic diagram of the system structure of the embodiment 1 of the present application;

[0091] Figure 2 is a schematic diagram of the system structure of the embodiment 2 of the present application.

[0092] In the figure, 1. Coal slurry buffer tank, 2. Feeding pump, 3. Coarse coal dewatering machine, 4. Dilute liquid tank, 5. Concentration tank, 6. Water treatment system, 7. Underflow pump, 8. Fine coal dewatering machine, 9. Dewatered fine coal belt, 10. Fine coal delivery belt, 11. Spiral material receiving bin, 12. Fine coal kneading machine, 13. Kneading tank, 14. Kneading pump, 15. Dewatered coarse coal scraper, 16. Coarse coal delivery belt, 17. Coarse coal kneading machine, 18. Finished product slurry tank, 19. Additive buffer tank, 20. Additive pump, 21. Total valve XV01, 22. Flow regulating valve FV01, 23. Flow meter FT01, 24. Flow regulating valve FV02, 25. Flow meter FT02, 26. Flow regulating valve FV03, 27. Flow meter FT03, 28. Coarse slurry tank, 29. Coarse slurry pump, 30. Fine grinder, 31. Fine slurry tank, 32. Fine slurry pump, 33. Production water buffer tank, 34. Production water pump. DETAILED DESCRIPTION

[0093] The preferred embodiments described herein are used to illustrate and explain the present application, and are not used to limit the present application.

[0094] Embodiment 1

[0095] The present application provides a system for preparing high-concentration coal water slurry by mixing and dewatering coarse and fine coal from pipe coal slurry, as shown in the figure, which comprises a coal slurry storage system, a coal slurry dewatering system, a coal slurry kneading system, a dewatered coal delivery system, and an additive supply system. Figure 1 The pipe coal slurry mixing coal powder is all from the product of pipe coal slurry dewatering, realizing the mode of one pulp, one use, and one to many.

[0096] The coal slurry buffer tank 1 is connected to the inlet of the feeding pump 2 through a pipeline, and the outlet of the feeding pump 2 is divided into two branch pipelines, one of which is connected to the inlet of the coarse coal dewatering machine 3, and the other is connected to the inlet of the coarse coal kneading machine 17.

[0097] The other branch pipeline of the feeding pump 2 is connected to the inlet of the fine coal kneading machine 12; the outlet of the additive buffer tank 19 is connected to the inlet of the additive pump 20 through a pipeline, and the outlet of the additive pump 20 is divided into two branch pipelines, one of which is connected to the coarse coal kneading machine 17, and the other is connected to the fine coal kneading machine 12.

[0098] The main pipeline after the feeding pump 2 is provided with a total valve XV01 (21), and the two branch pipelines are respectively provided with a flow regulating valve FV01 (22) and a flow meter FT01 (23), a flow regulating valve FV02 (24) and a flow meter FT02 (25).

[0099] The dewatering coarse coal scraper 15 is provided with two discharge ports, which are connected to the coarse coal conveying belt 16 and the coarse coal kneading machine 17 respectively, and the amount of dewatered coarse coal for conveying and blending and thickening can be adjusted by adjusting the size of the discharge port;

[0100] The fine coal kneading machine has three kinds of feed, which are dewatered fine coal, pipeline coal slurry and additives; and the discharge is dewatered fine slurry.

[0101] The coarse coal kneading machine has three kinds of feed, which are dewatered coarse coal, dewatered fine slurry and additives; and the discharge is high-concentration coal water slurry.

[0102] The coal powder mixed by the pipeline coal slurry is all from the product of pipeline coal slurry dewatering, which can enter the thickening system for slurry preparation, or can not enter the thickening system for export.

[0103] Example 2

[0104] The application provides a system for preparing high-concentration coal water slurry by mixing and dewatering coarse and fine coal, which comprises a coal slurry storage system, a coal slurry dewatering system, a coal slurry fine grinding system, a coal slurry kneading and mixing system, a dewatered coal conveying system, an additive supply system and a production water supply system. Figure 2 As shown in the figure, the system comprises a coal slurry storage system, a coal slurry dewatering system, a coal slurry fine grinding system, a coal slurry kneading and mixing system, a dewatered coal conveying system, an additive supply system and a production water supply system.

[0105] The outlet of the coal slurry buffer tank 1 is connected to the inlet of the feeding pump 2 through a pipeline. The outlet of the feeding pump 2 is divided into two branch pipelines. One of the branch pipelines is connected to the inlet of the coarse coal dewatering machine 3. The outlet of the coarse coal dewatering machine 3 is directly below a dewatered coarse coal scraper 15. The outlet of the dewatered coarse coal scraper 15 is connected to the coarse coal conveying belt 16 and the inlet of the coarse coal kneading and mixing machine 17. The outlet of the coarse coal kneading and mixing machine 17 is connected to the inlet of the finished slurry tank 18 through a pipeline. The liquid outlet of the coarse coal dewatering machine 3 is connected to the inlet of the dilute liquid tank 4 through a pipeline. The outlet of the dilute liquid tank 4 is connected to the thickening tank 5 through a pipeline. The overflow of the thickening tank 5 is discharged as coal slurry water, which is collected through a pipeline and discharged into the water treatment system 6. The coal slurry at the bottom of the thickening tank 5 is conveyed into the fine coal dewatering machine 8 by the underflow pump 7. The outlet of the fine coal dewatering machine 8 is directly below the dewatered fine coal belt 9. The outlet of the dewatered fine coal belt 9 is connected to the fine coal conveying belt 10 and the inlet of the screw receiving bin 11. The outlet of the screw receiving bin 11 is connected to the inlet of the fine coal kneading and mixing machine 12 through a pipeline. The outlet of the fine coal kneading and mixing machine 12 is connected to the inlet of the kneading and mixing tank 13 through a pipeline. The outlet of the kneading and mixing tank 13 is connected to the inlet of the kneading and mixing pump 14 through a pipeline. The outlet of the kneading and mixing pump 14 is connected to the inlet of the coarse coal kneading and mixing machine 17.

[0106] The other branch pipeline of the feeding pump 2 is connected to the inlet of the coarse slurry tank 28. The outlet of the coarse slurry tank is connected to the inlet of the coarse slurry pump 29 through a pipeline. The outlet of the coarse slurry pump 29 is connected to the inlet of the fine grinding machine 30 through a pipeline. The outlet of the fine grinding machine 30 is connected to the inlet of the fine slurry tank 31 through a pipeline. The outlet of the fine slurry tank 31 is connected to the inlet of the fine slurry pump 29 through a pipeline. The outlet of the fine slurry pump 29 is connected to the inlet of the fine coal kneading and mixing machine 12 through a pipeline. The outlet of the additive buffer tank 19 is connected to the inlet of the additive pump 20 through a pipeline. The outlet of the additive pump 20 is divided into two branch pipelines. One of the branch pipelines is connected to the coarse coal kneading and mixing machine 17. The other branch pipeline is connected to the inlet of the coarse slurry tank 28. The outlet of the production water buffer tank 33 is connected to the inlet of the production water pump 34. The outlet of the production water pump 34 is connected to the inlet of the coarse slurry tank 28 through a pipeline.

[0107] The pipeline after the fine slurry pump 32 is provided with a flow regulating valve FV03 (reference numeral 26) and a flow meter FT03 (reference numeral 27) for controlling and adjusting the flow of the fine slurry into the fine coal kneading and mixing machine.

[0108] The fine grinding machine 30 has requirements for the particle size, concentration and outlet particle size of the feeding coal slurry, and the pipe-conveyed coal slurry needs to be diluted and viscosity-reduced by adding production water and additives.

[0109] The feed of the fine coal kneader has two kinds, which are dehydrated fine coal and fine slurry respectively; and the output is dehydrated fine slurry.

[0110] The feed of the coarse coal kneader has three kinds, which are dehydrated coarse coal, dehydrated fine slurry and additive respectively; and the output is high-concentration coal water slurry.

[0111] The feed of the coarse slurry tank has three kinds, which are pipe-transported coal slurry, additive and production water respectively; and the output is coarse slurry.

[0112] Example 3

[0113] In this example, the conventional-concentration pipe-transported coal slurry is prepared by using Hongliulin 5-2 washed and mixed coal, the pipe-transported coal slurry is transported to the thickening workshop through long-distance pipeline, the blending and thickening production process is carried out, the high-concentration coal water slurry is prepared according to the customer's slurry demand, and the concentrations, ash contents and particle size gradations of the pipe-transported coal slurry, dehydrated coarse coal, dehydrated fine coal, dehydrated fine slurry and high-concentration coal water slurry are shown in Table 3 below, which specifically includes the following steps:

[0114] Table 3 Properties of raw materials, intermediate products and final products

[0115]

[0116] Step 1, the pipe-transported coal slurry with a concentration of 51-55% is stored in the coal slurry buffer tank for continuous stirring, and is transported to the coarse coal dehydrator through the inlet pump, and the valve FV01 and the flow meter FT01 control and measure the dehydration flow rate;

[0117] Step 2, after the coarse coal is dehydrated, the dilute liquid with a concentration of 15-20% and the dehydrated coarse coal with a moisture content of 16-23% are produced, wherein the dilute liquid is collected into the dilute liquid tank for stirring and storage through the pipeline, and the dehydrated coarse coal falls into the dehydrated coarse coal scraper, and then falls into the coarse coal external conveying belt and the coarse coal kneader through the discharge port;

[0118] Step 3, the dilute liquid is transported to the concentration tank for concentration and sedimentation, wherein the supernatant (concentration about 5-10%) overflows into the water treatment system for deep treatment and discharge, and the concentrated underflow (concentration 15-30%) is transported to the fine coal dehydrator for dehydration through the underflow pump;

[0119] Step 4, the dehydration produces dehydrated fine coal with a moisture content of 22-29%, which falls into the dehydrated fine coal belt, and then falls into the fine coal external conveying belt and the spiral material receiving bin through the discharge port;

[0120] Step 5, the pipe-transported coal slurry is transported into the fine coal kneader through the inlet pump, and the valve FV02 and the flow meter FT02 control and adjust the pipe-transported coal slurry flow rate into the fine coal kneader 12;

[0121] Step 6, the dehydrated fine coal is stored and stirred in the spiral receiving bin, and is transported to the fine coal kneader to be kneaded with the pipe-conveyed coal slurry with a concentration of 51-55% and the additive solution with a concentration of 8-15% to form the dehydrated fine slurry with a concentration of 45-60%, wherein the additive (dry powder) is added in an amount of 0.1-0.2% of the total amount of the coal (dry basis).

[0122] Step 7, the dehydrated fine slurry is transported into the kneading tank after being kneaded in the fine coal kneader, and is stored and stirred uniformly, and is transported into the coarse coal kneader by the kneading pump to be kneaded with the dehydrated coarse coal with a moisture content of 16-23% and the additive solution with a concentration of 8-15% in the coarse coal kneader to form the high-concentration coal water slurry with a concentration of 64-68%, and is stored and transported in the finished slurry tank 18, wherein the additive (dry powder) is added in an amount of 0.1-0.2% of the total amount of the coal (dry basis).

[0123] In this embodiment, the pipe-conveyed coal slurry has a concentration of 52.39%, an ash content of 11.82%, a -325 mesh particle size ratio of 24.64%, a -200 mesh particle size ratio of 32.77%, a -48 mesh particle size ratio of 72.34%, a -14 mesh particle size ratio of 98.4%, and a +14 mesh particle size ratio of 1.59%.

[0124] The dehydrated coarse coal has a moisture content of 21.15%, an ash content of 9.34%, a -325 mesh particle size ratio of 12.34%, a -200 mesh particle size ratio of 20.42%, a -48 mesh particle size ratio of 67.38%, a -14 mesh particle size ratio of 97.71%, and a +14 mesh particle size ratio of 2.29%.

[0125] The dehydrated fine coal has a moisture content of 26.74%, an ash content of 14.38%, a -325 mesh particle size ratio of 49.4%, a -200 mesh particle size ratio of 61.22%, a -48 mesh particle size ratio of 83.26%, a -14 mesh particle size ratio of 99.51%, and a +14 mesh particle size ratio of 0.49%.

[0126] The dehydrated fine slurry has a concentration of 58.20%.

[0127] The high-concentration coal water slurry has a concentration of 65.14%, an ash content of 11.26%, a -325 mesh particle size ratio of 24.6%, a -200 mesh particle size ratio of 33.49%, a -48 mesh particle size ratio of 72.34%, a -14 mesh particle size ratio of 98.05%, and a +14 mesh particle size ratio of 1.65%.

[0128] In this embodiment, the dry basis amount ratio of the pipe-conveyed coal slurry, the dehydrated coarse coal and the dehydrated fine coal is 34.3:43.6:21.8.

[0129] In this embodiment, the total amount of the additive (dry powder) is 0.3% of the total amount of the coal (dry basis).

[0130] In this embodiment, after the pipe-conveyed coal slurry enters the dewatering system, the coarse coal dewatering recovery rate is 65-70%, the fine coal dewatering recovery rate is 30-35%, and the dewatering produces surplus dewatered coarse coal and dewatered fine coal which are stored in separate bins, and are classified and sold according to user requirements.

[0131] Embodiment 4

[0132] In this embodiment, the Hongliulin 5-2 washed mixed coal is used to prepare conventional concentration pipe-conveyed coal slurry, the pipe-conveyed coal slurry is transported by long-distance pipeline to the thickening workshop, the blending and thickening production process is carried out, the high-concentration coal water slurry is prepared according to the customer's slurry requirements, and the concentration, ash content and particle size distribution of the pipe-conveyed coal slurry, dewatered coarse coal, dewatered fine coal, fine slurry, dewatered fine slurry and high-concentration coal water slurry are shown in Table 4 below, which specifically includes the following steps:

[0133] Table 4 Properties of raw materials, intermediate products and final products

[0134]

[0135] Step 1, the pipe-conveyed coal slurry with a concentration of 51-55% is stored in the coal slurry buffer tank for continuous stirring, is transported to the coarse coal dewatering machine for dewatering by the feed pump, and the dewatering flow is controlled and metered by the valve FV01 and the flow meter FT01;

[0136] Step 2, the coarse coal dewatering machine produces dilute liquid with a concentration of 15-20% and dewatered coarse coal with a moisture content of 16-23%, wherein the dilute liquid is collected into the dilute liquid tank for stirring and storage, and the dewatered coarse coal falls into the dewatered coarse coal scraper, and then falls into the coarse coal external conveying belt and the coarse coal kneading machine through the discharge port;

[0137] Step 3, the dilute liquid is transported to the concentration tank for concentration and sedimentation, wherein the supernatant (concentration about 5-10%) overflows into the water treatment system for deep treatment and discharge, and the concentrated underflow (concentration 15-30%) is transported to the fine coal dewatering machine for dewatering by the underflow pump;

[0138] Step 4, the fine coal dewatering machine produces dewatered fine coal which falls into the dewatered fine coal belt, and then falls into the fine coal external conveying belt and the screw receiving bin through the discharge port;

[0139] Step 5, the pipe-conveyed coal slurry with a concentration of 51-55% is transported into the coarse slurry tank by the feed pump, and the valve FV02 and the flow meter FT02 control and adjust the pipe-conveyed coal slurry flow into the coarse slurry tank;

[0140] Step 6, the pipe-conveyed coal slurry with a concentration of 51-55% in the coarse slurry tank is mixed with additive solution with a concentration of 8-15% and production water to form coarse slurry with a concentration of 37-42%, which is transported to the fine grinder by the coarse slurry pump for grinding to form fine slurry with a concentration of 37-42%, wherein the additive (dry powder) is added in an amount of 0.1-0.2% of the total amount of coal (dry basis);

[0141] Step 7, the fine slurry is transported into the fine slurry tank for storage and stirring, and is transported into the fine coal kneader by the fine slurry pump 32, which is provided with a valve FV03 and a flow meter FT03 for controlling and adjusting the flow of the fine slurry into the fine coal kneader 12;

[0142] Step 8, the dewatered fine coal is stored and stirred in the spiral receiving bin, and is transported into the fine coal kneader to be strongly kneaded with the fine slurry to form dewatered fine slurry with a concentration of 45-60%;

[0143] Step 9, the dewatered fine slurry is stored and stirred in the kneading tank 13, and is transported into the coarse coal kneader by the kneading pump to be strongly kneaded with the dewatered coarse coal with a moisture content of 16-23% and the additive solution with a concentration of 8-15% in the coarse coal kneader to form high-concentration coal water slurry with a concentration of 64-68%, which is stored and transported in the finished slurry tank 18, wherein the additive (dry powder) is added in an amount of 0.1-0.2% of the total amount of coal (dry basis).

[0144] In this embodiment, the pipe-transported coal slurry has a concentration of 52.39%, an ash content of 11.82%, a -325 mesh particle size ratio of 24.64%, a -200 mesh particle size ratio of 32.77%, a -48 mesh particle size ratio of 72.34%, a -14 mesh particle size ratio of 98.4%, and a +14 mesh particle size ratio of 1.59%.

[0145] The dewatered coarse coal has a moisture content of 21.15%, an ash content of 9.34%, a -325 mesh particle size ratio of 12.34%, a -200 mesh particle size ratio of 20.42%, a -48 mesh particle size ratio of 67.38%, a -14 mesh particle size ratio of 97.71%, and a +14 mesh particle size ratio of 2.29%.

[0146] The dewatered fine coal has a moisture content of 26.74%, an ash content of 14.38%, a -325 mesh particle size ratio of 49.4%, a -200 mesh particle size ratio of 61.22%, a -48 mesh particle size ratio of 83.26%, a -14 mesh particle size ratio of 99.51%, and a +14 mesh particle size ratio of 0.49%.

[0147] The coarse slurry has a concentration of 40% and an ash content of 11.82%.

[0148] The fine slurry has a concentration of 40%, an ash content of 11.82%, a -325 mesh particle size ratio of 75.37%, a -200 mesh particle size ratio of 84.21%, a -48 mesh particle size ratio of 96.59%, a -14 mesh particle size ratio of 100%, and a +14 mesh particle size ratio of 0%.

[0149] The dewatered fine slurry has a concentration of 58.18%.

[0150] The high-concentration coal water slurry has a concentration of 64.68%, an ash content of 11.82%, a -325 mesh particle size ratio of 38.43%, a -200 mesh particle size ratio of 48.16%, a -48 mesh particle size ratio of 78.75%, a -14 mesh particle size ratio of 98.55%, and a +14 mesh particle size ratio of 1.45%.

[0151] In this embodiment, the dry basis amount ratio of the pipe-transported coal slurry, the dewatered coarse coal and the dewatered fine coal is 17.2:41.3:41.3.

[0152] In this embodiment, the total amount of the additive (dry powder) is 0.3% of the total amount of the coal (dry basis).

[0153] In this embodiment, after the pipe-transported coal slurry enters the dewatering system, the dewatering recovery rate is about 65-70%, the dewatering recovery rate is 30-35%, and the dewatering produces surplus dewatered coarse coal and dewatered fine coal which are stored in separate bins and sold according to user requirements.

[0154] Finally, it should be noted that the above only describes the preferred embodiments of the present application and is not intended to limit the present application. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent replacements to some technical features. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A system for preparing high-concentration coal-water slurry by blending and dewatering coarse and fine coal in pipeline coal slurry, characterized in that, The coal slurry storage system, the coal slurry dehydration system, the coal slurry fine grinding system, the coal slurry kneading system, the dehydrated coal conveying system, the additive supply system and the process water supply system are all connected with the pipeline transportation coal slurry. The coal slurry buffer tank (1) is connected with the inlet of the feeding pump (2) through a pipeline, and the outlet of the feeding pump (2) is divided into two branch pipelines, one of which is connected with the inlet of the coarse coal dehydration machine (3), and the other of which is connected with the inlet of the fine coal dehydration machine (8). The other branch pipeline of the feeding pump (2) is connected with the inlet of the fine coal kneading machine (12). The outlet of the additive buffer tank (19) is connected with the inlet of the additive pump (20) through a pipeline, and the outlet of the additive pump (20) is divided into two branch pipelines, one of which is connected with the coarse coal kneading machine (17), and the other of which is connected with the fine coal kneading machine (12).

2. The system for preparing high concentration coal water slurry from coal slurry mixing and dewatering coarse and fine coal according to claim 1, characterized in that, The main pipeline after the feeding pump (2) is provided with a total valve XV01 (21), and the two branch pipelines are respectively provided with a flow regulating valve FV01 (22) and a flow meter FT01 (23), and a flow regulating valve FV02 (24) and a flow meter FT02 (25).

3. The system for preparing high concentration coal water slurry from coal slurry mixing and dewatering coarse and fine coal according to claim 2, characterized in that, The dehydration coarse coal scraper (15) is provided with two discharge openings, which are connected with the coarse coal conveying belt (16) and the coarse coal kneading machine (17) respectively, and the amount of the dehydration coarse coal for conveying and blending is adjusted by adjusting the size of the discharge openings. The dehydration fine coal belt (9) is provided with two discharge openings, which are connected with the fine coal conveying belt (10) and the screw material receiving bin (11) respectively, and the amount of the dehydration fine coal for conveying and blending is adjusted by adjusting the size of the discharge openings.

4. The system for preparing high-concentration coal water slurry by mixing and dewatering coarse and fine coal, characterized in that, The coal slurry storage system, the coal slurry dehydration system, the coal slurry fine grinding system, the coal slurry kneading system, the dehydrated coal conveying system, the additive supply system and the process water supply system are all connected with the pipeline transportation coal slurry. The system further comprises a production water supply system; the coal slurry buffer tank (1) is connected with the inlet of the feeding pump (2) through a pipeline, the outlet of the feeding pump (2) is divided into two branch pipelines, one of the branch pipelines is connected with the inlet of the coarse coal dewatering machine (3), the coarse coal dewatering machine (3) is provided with a dewatering coarse coal scraper (15) below the discharge port of the coarse coal dewatering machine (3), one of the discharge ports of the dewatering coarse coal scraper (15) is connected with the coarse coal conveying belt (16), and the other is connected with the inlet of the coarse coal kneading machine (17); the liquid discharge end of the coarse coal dewatering machine (3) is connected with the inlet of the dilute liquid tank (4) through a pipeline, the outlet of the dilute liquid tank (4) is connected with the thickening tank (5) through a pipeline, the overflow port of the thickening tank (5) discharges coal slurry, the coal slurry is collected through a pipeline and discharged into the water treatment system (6), and the coal slurry at the bottom of the thickening tank (5) is transported into the fine coal dewatering machine (8) by the underflow pump (7); the fine coal dewatering machine (8) is provided with a dewatering fine coal belt (9) below the discharge port of the fine coal dewatering machine (8), one of the discharge ports of the dewatering fine coal belt (9) is connected with the fine coal conveying belt (10), and the other is connected with the inlet of the screw receiving bin (11); the discharge port of the screw receiving bin (11) is connected with the inlet of the fine coal kneading machine (12) through a pipeline, the discharge port of the fine coal kneading machine (12) is connected with the inlet of the kneading tank (13) through a pipeline, the outlet of the kneading tank (13) is connected with the inlet of the kneading pump (14) through a pipeline, and the outlet of the kneading pump (14) is connected with the inlet of the coarse coal kneading machine (17); the other branch pipeline of the feeding pump (2) is connected with the inlet of the coarse slurry tank (28), the outlet of the coarse slurry tank is connected with the inlet of the coarse slurry pump (29) through a pipeline, the outlet of the coarse slurry pump (29) is connected with the inlet of the fine grinder (30) through a pipeline, the outlet of the fine grinder (30) is connected with the inlet of the fine slurry tank (31) through a pipeline, the outlet of the fine slurry tank (31) is connected with the inlet of the fine slurry pump (32) through a pipeline, and the outlet of the fine slurry pump (32) is connected with the inlet of the fine coal kneading machine (12); the outlet of the additive buffer tank (19) is connected with the inlet of the additive pump (20) through a pipeline, the outlet of the additive pump (20) is divided into two branch pipelines, one of the branch pipelines is connected with the coarse coal kneading machine (17), and the other is connected with the inlet of the coarse slurry tank (28); the outlet of the production water buffer tank (33) is connected with the inlet of the production water pump (34), and the outlet of the production water pump (34) is connected with the inlet of the coarse slurry tank (28) through a pipeline.

5. The system for preparing high concentration coal water slurry from coal slurry mixing and dewatering coarse and fine coal according to claim 4, characterized in that, The fine slurry pump (32) is provided with a flow regulating valve FV03 (26) and a flow meter FT03 (27) after the fine slurry pump (32), which are used for adjusting and controlling the amount of fine slurry entering the fine coal kneading machine (12).

6. A method for preparing high concentration coal water slurry by mixing and dewatering coarse and fine coal, characterized in that, The system of claim 3 is used in the following specific operation: Step 1, open the total valve XV01 (21) and the flow regulating valve FV01 (22), the pipeline coal slurry is stored in the coal slurry buffer tank (1) and continuously stirred, is transported to the coarse coal dewatering machine (3) through the feeding pump (2) for dewatering, and the flow regulating valve FV01 (22) and the flow meter FT01 (23) control and measure the dewatering flow rate; Step 2, after the crude coal dewatering machine (3) dewatering, the dilute liquid is collected in the dilute liquid tank (4) and the dewatered crude coal is collected in the dewatered crude coal scraper (15) below the discharge port of the crude coal dewatering machine (3), and then is collected in the crude coal external conveying belt (16) and the crude coal kneading machine (17), and is conveyed into the coal storage bin for storage and external sale by the crude coal external conveying belt (16); Step 3, the dilute liquid in the dilute liquid tank (4) is conveyed into the concentration tank (5) by a pipe and a pump for concentration and precipitation, the supernatant is overflowed into the water treatment system (6) for deep treatment and discharge, and the concentrated underflow is conveyed into the fine coal dewatering machine (8) by the underflow pump (7) for dewatering; Step 4, the dewatered fine coal produced by the fine coal dewatering machine (8) is collected in the dewatered fine coal belt (9) below, and then is collected in the fine coal external conveying belt (10) and the spiral receiving bin (11) by the discharge port, and is conveyed into the coal storage bin for storage and external sale by the fine coal external conveying belt (10); Step 5, the flow regulating valve FV02 (24) is opened, the pipe-conveyed coal slurry is conveyed into the fine coal kneading machine (12) by another branch line after the inlet pump (2), and the flow regulating valve FV02 (24) and the flow meter FT02 (25) control and regulate the pipe-conveyed coal slurry flow into the fine coal kneading machine (12), that is, control and regulate the pipe-conveyed coal slurry blending ratio; Step 6, the dewatered fine coal is buffered and stirred in the spiral receiving bin (11), is conveyed into the fine coal kneading machine (12) by a pipe, and is strongly kneaded with the pipe-conveyed coal slurry conveyed by another branch line after the inlet pump (2) and the additive solution conveyed by the additive pump (20) to form dewatered fine slurry; Step 7, after the dewatered fine slurry is kneaded in the fine coal kneading machine (12), it is conveyed into the kneading tank (13) by a pipe, is buffered and stirred again, and is conveyed into the kneading pump (14) by the bottom discharge pipe; Step 8, the dewatered fine slurry is conveyed into the coarse coal kneading machine (17) by the kneading pump (14), is strongly kneaded with the dewatered coarse coal collected in the coarse coal kneading machine (17) by the dewatered coarse coal scraper (15) and the additive solution conveyed by the additive pump (20) to form high-concentration coal water slurry, and is conveyed into the finished slurry tank (18) by a pipe for buffering, and is transported by a pipe or a tank truck according to the distance and requirements of the user; The pipe-conveyed coal slurry is dewatered to form dewatered coarse coal and dewatered fine coal, the pipe-conveyed coal slurry, the dewatered fine coal and the additive are kneaded and viscosity-reduced to form dewatered fine slurry, and the dewatered fine slurry, the dewatered coarse coal and the additive are kneaded to form high-concentration coal water slurry; The ratio of the pipe-conveyed coal slurry, the dewatered coarse coal and the dewatered fine coal is: The concentration of the dewatered fine slurry is: The concentration of the high-concentration coal water slurry is: The ash content of the high-concentration coal water slurry is: The particle size grading of the high-concentration coal water slurry is: The ratio of the total additive amount to the total coal amount is: Wherein, , Respectively, the particle size of the pipe coal slurry, the dewatered coarse coal, and the dewatered fine coal; i Indicates the grade, taking 1-5; The +14 mesh screen oversize ratio; The +48 mesh screen oversize ratio; The +200 mesh screen oversize ratio; The +325 mesh screen oversize ratio; The -325 mesh screen undersize ratio; , , The sum of the particle sizes is 100; the percentage of the amount of additive dry powder to the total amount of coal: wherein, C 1 is the pipe-transported coal slurry concentration, C 2 is the dewatered fine coal concentration, C 3 is the high-concentration coal water slurry concentration, C 4 is the additive solution concentration; is the pipe-transported coal slurry density; Q1 is the total pipe-transported coal slurry flow rate; is the pipe-transported coal slurry ash content, is the dewatered coarse coal ash content, is the dewatered fine coal ash content, is the pipe-transported coal slurry flow rate into the dewatering system, is the pipe-transported coal slurry flow rate into the fine coal kneader-mixer, is the total additive solution flow rate, is the additive solution flow rate into the fine coal kneader-mixer, is the additive solution flow rate into the coarse coal kneader-mixer, is the dewatered coarse coal moisture content, is the dewatered fine coal moisture content, is the dewatered coarse coal flow rate, is the dewatered fine coal flow rate, is the additive dry powder usage percentage of the total coal amount.

7. A method for preparing high concentration coal water slurry by mixing and dewatering coarse and fine coal, characterized in that, The system of claim 5 is used, and the specific operation is as follows: Step 1, the total valve XV01 (21) and the flow regulating valve FV01 (22) are opened, the pipe-conveyed coal slurry is stored in the coal slurry buffer tank (1) for continuous stirring, is conveyed into the coarse coal dewatering machine (3) by the inlet pump (2) for dewatering, and the flow regulating valve FV01 (22) and the flow meter FT01 (23) control and measure the dewatering flow; Step 2, after the coarse coal dewatering machine (3) dewatering, the dilute liquid is collected in the dilute liquid tank (4) and the dewatered coarse coal is collected in the dewatered coarse coal scraper (15) below the discharge port of the coarse coal dewatering machine (3), and then falls into the coarse coal conveying belt (16) and the coarse coal kneading machine (17), and is conveyed into the coal storage bin by the coarse coal conveying belt (16) for storage and sale; Step 3, the dilute liquid in the dilute liquid tank (4) is pumped into the thickening tank (5) through a pipeline and a pump for concentration and sedimentation, the supernatant is overflowed into the water treatment system (6) for deep treatment and discharge, and the concentrated underflow is pumped into the fine coal dewatering machine (8) through the underflow pump (7) for dewatering; Step 4, the fine coal dewatering machine (8) dewatering produces fine coal which falls into the dewatered fine coal belt (9) below, and then falls into the fine coal conveying belt (10) and the spiral receiving bin (11) through the discharge port, and is conveyed into the coal storage bin by the fine coal conveying belt (10) for storage and sale; Step 5, open the flow regulating valve FV02 (24), and the pipeline coal slurry after the inlet pump (2) is conveyed into the coarse slurry tank (28) through another branch pipeline, the flow regulating valve FV02 (24) and the flow meter FT02 (25) control and adjust the pipeline coal slurry flow entering the coarse slurry tank (28), that is, control and adjust the fine grinding blending ratio of the pipeline coal slurry; Step 6, the additive solution is stored in the additive buffer tank (19) and stirred uniformly, and is conveyed into the coarse slurry tank (28) and the coarse coal kneading machine (17) through two branch pipelines by the additive pump (20) to reduce the viscosity of the pipeline coal slurry entering the coarse slurry tank (28) and the high-concentration coal water slurry entering the coarse coal kneading machine (17); Step 7, the production water is stored in the production water buffer tank (33) and is conveyed into the coarse slurry tank (28) by the production water pump (34) to dilute the concentration of the pipeline coal slurry entering the coarse slurry tank (28); Step 8, after the pipeline coal slurry in the coarse slurry tank (28) is diluted and the viscosity is reduced, the pipeline coal slurry is conveyed into the fine grinding machine (30) by the coarse slurry pump (29) to reduce the particle size of the pipeline coal slurry and form fine slurry; Step 9, the fine slurry ground by the fine grinding machine (30) is conveyed into the fine slurry tank (31) through a pipeline for buffering and stirring, and is conveyed into the fine coal kneading machine (12) by the fine slurry pump (32), and the fine slurry pump (32) is provided with a flow regulating valve FV03 (26) and a flow meter FT03 (27) to control and adjust the fine slurry flow entering the fine coal kneading machine (12), so as to adjust the fine slurry blending ratio of the pipeline coal slurry grinding; Step 10, the dewatered fine coal is buffered and stirred in the spiral receiving bin (11), is conveyed into the fine coal kneading machine (12) through a pipeline, and is strongly kneaded with the fine slurry conveyed by the fine slurry pump (32) to form dewatered fine slurry; Step 11, after the dewatered fine slurry is kneaded in the fine coal kneading machine (12), the dewatered fine slurry is conveyed into the kneading pump (14) through a pipeline for buffering and stirring again. Step 12, the dewatered fine slurry is transported into the coarse coal kneader (17) by the kneading pump (14), and is strongly kneaded with the dewatered coarse coal falling into the coarse coal kneader (17) by the dewatered coarse coal scraper (15) and the additive solution transported by the additive pump (20) to form high-concentration coal water slurry, which is transported into the finished slurry tank (18) by pipeline for buffering, and is transported by pipeline or tank truck according to the distance and requirements of users; The dewatered coarse coal and the dewatered fine coal are formed after the pipeline coal slurry is dewatered, the dewatered fine slurry is formed after the fine slurry, the dewatered fine coal and the additive are kneaded and the viscosity is reduced, the coarse slurry is formed after the pipeline coal slurry and the process water and the additive are diluted and the viscosity is reduced, the fine slurry is formed after the coarse slurry is ground by the fine grinder, and the high-concentration coal water slurry is formed after the dewatered fine slurry, the dewatered coarse coal and the additive are kneaded; The ratio of the pipeline coal slurry, the dewatered coarse coal and the dewatered fine coal is: The concentration of the dewatered fine slurry is: The concentration of the pipeline coal slurry is: The concentration of the high-concentration coal water slurry is: The ash content of the high-concentration coal water slurry is: The particle size grading of the high-concentration coal water slurry is: wherein, , are particle sizes of the pipe transported coal slurry, the dewatered coarse coal, and the dewatered fine coal, respectively; i represents a grade, and is taken as 1-5; is a proportion of +14 mesh oversize; is a proportion of +48 mesh oversize; is a proportion of +200 mesh oversize; is a proportion of +325 mesh oversize; is a proportion of -325 mesh undersize; , , the sum of the particle sizes is 100; The percentage of the additive dry powder in the total coal is: wherein, C 1 is the pipe-transported coal slurry concentration, C 2 is the dewatered coarse slurry concentration, C 3 is the high-concentration coal water slurry concentration, C 4 is the additive solution concentration, C 9 is the fine slurry concentration; is the pipe-transported coal slurry density; Q1 is the total flow rate of the pipe-transported coal slurry; is the ash content of the pipe-transported coal slurry, is the ash content of the dewatered coarse coal, is the ash content of the dewatered fine coal, is the flow rate of the pipe-transported coal slurry into the dewatering system, is the flow rate of the pipe-transported coal slurry into the coarse slurry tank, is the total flow rate of the additive solution, is the flow rate of the additive solution into the coarse coal kneader, is the flow rate of the additive solution into the coarse slurry tank, is the fine slurry flow rate, is the flow rate of the produced water; is the moisture content of the dewatered coarse coal, is the moisture content of the dewatered fine coal, is the flow rate of the dewatered coarse coal, is the flow rate of the dewatered fine coal, is the percentage of the total coal amount used for the additive dry powder.

8. The method according to claim 6 or 7, wherein the high concentration coal water slurry is prepared by mixing and dehydrating the coarse and fine coal slurry. The additive dry powder includes a naphthalene system and a lignin sulfonate compound or a single substance, and the additive solution is a solution with a mass concentration of 10% prepared by adding water to the additive dry powder.

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