Zhundong coal water slurry and preparation method thereof

Abstract

The invention provides Zhundong coal water-coal slurry and a preparation method thereof, and particularly discloses the water-coal slurry which comprises the following components in parts by mass: 55-65 parts of mixed coal powder, 35-45 parts of water and 0.01-3 parts of a dispersing agent, the mixed pulverized coal comprises particles A, particles B and particles C; the particles A and the particles B are Zhundong pulverized coal particles, and the particles C are selected from one or more of Zhundong pulverized coal particles, Shenfu pulverized coal particles, petroleum coke, bituminous coal particles, anthracite particles, carbon spheres, silicon dioxide or aluminum oxide; the mass ratio of the particles A to the particles B to the particles C is 6: (0.7-1.3): (2-4); the dispersing agent is naphthalene sulfonate. The Zhundong coal water slurry provided by the invention is low in viscosity, good in fluidity, high in slurry concentration and high in carbon conversion rate when being used for gasification.

Description

Technical Field

[0001] The invention relates to a Zhundong coal-water slurry and a preparation method thereof. Background Art

[0002] Zhundong coal reserves are rich, with a total proven coal resource reserve of 213.6 billion tons, making it the largest integrated coalfield in my country. The development of Zhundong coal mines has promoted the rapid economic growth of the region through the extension of the coal-electricity and coal-chemical industry chain, providing solid support for the national energy strategy and regional economic development, and has important strategic significance. Therefore, the clean and efficient use of Zhundong coal has received widespread attention.

[0003] Gasification is one of the key technologies for clean and efficient utilization of coal. Large-scale water-coal slurry entrained-bed gasification is an advanced gasification technology currently used on a large scale. Since the quality of Zhundong coal is between bituminous coal and lignite, close to the characteristics of lignite, this type of coal has the characteristics of high moisture, high volatile matter, low ash content, and low sulfur content. It is difficult to prepare a water-coal slurry with a higher concentration, which is not conducive to the use of water-coal slurry gasification. The industry needs a water-coal slurry of Zhundong coal with high concentration and high carbon conversion rate. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the defect of low slurry concentration of Zhundong coal slurry in the prior art, and to provide a new Zhundong coal water slurry and a preparation method thereof. The Zhundong coal water slurry provided by the present invention has low viscosity, good fluidity, high slurry concentration, and high carbon conversion rate when used for gasification.

[0005] The present invention solves the above technical problems through the following technical solutions:

[0006] The present invention provides a water-coal slurry, which comprises the following components in parts by mass: 55-65 parts by mass of mixed coal powder, 35-45 parts by mass of water and 0.01-3 parts by mass of a dispersant;

[0007] The mixed coal powder comprises particles A, particles B and particles C;

[0008] The particles A are Zhundong coal powder particles, and the D32 particle size of the particles A ranges from 50 to 120 microns;

[0009] The particle B is Zhundong coal powder particle, and the particle size D32 of the particle B is in the range of 15-50 microns;

[0010] The particles C are selected from one or more of Zhundong coal powder particles, Shenfu coal powder particles, petroleum coke, bituminous coal particles, anthracite particles, carbon balls, silicon dioxide or aluminum oxide, and the particle size D32 of the particles C is in the range of 0.1-15 microns;

[0011] The mass fraction of the particle A accounts for more than 50% of the mixed coal powder, and the mass ratio of the particle A, particle B and particle C is 6: (0.7-1.3): (2-4);

[0012] The dispersant is naphthalene sulfonate.

[0013] The Zhundong coal powder is obtained by grinding or crushing Zhundong coal.

[0014] The Shenfu coal powder is obtained by grinding or crushing Shenfu coal.

[0015] In some embodiments, the mixed coal powder has an amount of 60-65 parts by mass; for example, 60 parts by mass or 65 parts by mass.

[0016] In some embodiments, the water has an amount of 35-40 parts by mass; for example, 35 parts by mass or 40 parts by mass.

[0017] In some embodiments, the mass part of the dispersant is 0.5-1.5 mass parts; for example, 1 mass part.

[0018] In some embodiments, the particles C are selected from one or both of Zhundong coal powder particles and Shenfu coal powder particles; preferably Shenfu coal powder particles.

[0019] In some embodiments, the mass ratio of particles A, particles B, and particles C is 6:1:3.

[0020] In some embodiments, the coal-water slurry further comprises a non-polar solvent, and the non-polar solvent is one or both of turpentine and kerosene.

[0021] In some embodiments, the mass fraction of the non-polar solvent is 0.01-3 mass fractions; such as 0.5-1.5 mass fractions; for example 0.5 or 1 mass fraction.

[0022] In some embodiments, the non-polar solvent is turpentine.

[0023] In some embodiments, the non-polar solvent is used by evenly applying it on the surface of particle C.

[0024] In some embodiments, the dispersant is a naphthalene-based dry powder dispersant.

[0025] In some embodiments, the solid content of the coal water slurry is 60-70 wt %; such as 60-65 wt % (for determination standard, see GB / T 18856.2-2002).

[0026] In some embodiments, the apparent viscosity of the coal water slurry is less than 1200 mPas (see GB / T18856.4-2002 for the determination standard).

[0027] In some embodiments, the moisture content of the Zhundong coal accounts for 0.5-15wt% of the total mass of the Zhundong coal, such as 5-10wt%; for example, 7wt%.

[0028] In some embodiments, the ash content of the Zhundong coal accounts for 1-25wt% of the total mass of the dry Zhundong coal, such as 5-10wt%; for example, 7wt%. (Dry Zhundong coal refers to Zhundong coal without moisture).

[0029] In some embodiments, the percentage of volatile matter of the Zhundong coal to the total mass of the dry Zhundong coal is 5-65wt%, such as 25-35wt%; for example, 34wt%.

[0030] In some embodiments, the percentage of fixed carbon in the Zhundong coal to the total mass of the dry Zhundong coal is 50-75wt%, such as 55-65wt%; for example 59wt%.

[0031] In some embodiments, the mass percentage of C element in the dried Zhundong coal is 60-85wt%, such as 70-80wt%; for example 74%.

[0032] In some embodiments, the mass percentage of O element in the dried Zhundong coal is 7-20wt%, such as 12-18wt%; for example, 14%.

[0033] In some embodiments, the mass percentage of H element in the dried Zhundong coal is 0.5-15wt%, such as 3-4wt%; for example, 3.5%.

[0034] In some embodiments, the mass percentage of N element in the dried Zhundong coal is 0.1-5wt%, such as 0.5-1.5 wt%; for example, 0.7%.

[0035] In some embodiments, the mass percentage of S element in the dried Zhundong coal is 0.01-5wt%, such as 0.2-0.8 wt%; for example, 0.5%.

[0036] In some embodiments, the moisture content of the Shenfu coal is 0.5-10wt%, such as 1-3wt%, or 2wt% based on the total mass of the Shenfu coal (dried Shenfu coal refers to Shenfu coal without moisture).

[0037] In some embodiments, the ash content of the Shenfu coal accounts for 1-25 wt %, such as 5-10 wt %, for example 6 wt %, of the total mass of the dry Shenfu coal.

[0038] In some embodiments, the percentage of volatile matter of the Shenfu coal to the total mass of the dry Shenfu coal is 10-55 wt%, such as 25-35 wt%; for example, 31 wt%.

[0039] In some embodiments, the percentage of fixed carbon in the Shenfu coal to the total mass of the dry Shenfu coal is 50-80 wt%, such as 58-68 wt%; for example 63 wt%.

[0040] In some embodiments, the mass percentage of C element in the dried Shenfu coal is 60-85wt%, such as 70-80wt%; for example 72%.

[0041] In some embodiments, the mass percentage of O element in the dried Shenfu coal is 7-20wt%, such as 12-18wt%; for example, 13%.

[0042] In some embodiments, the mass percentage of H element in the dried Shenfu coal is 0.5-15wt%, such as 3-4wt%; for example, 4%.

[0043] In some embodiments, the mass percentage of N element in the dried Shenfu coal is 0.5-5wt%, such as 1-3wt%; for example, 1.8%.

[0044] In some embodiments, the mass percentage of S element in the dried Shenfu coal is 0.01-5wt%, such as 1-2wt%; for example, 1.5%.

[0045] In some embodiments, the water-coal slurry is composed of the following components in parts by mass: 55-65 parts by mass of the mixed coal powder, 35-45 parts by mass of the water, 0.01-3 parts by mass of the dispersant, and 0-3 parts by mass of the non-polar solvent.

[0046] In some embodiments, the water-coal slurry includes the following components in parts by mass: 60-65 parts by mass of mixed coal powder, 35-40 parts by mass of water, 0.5-1.5 parts by mass of naphthalene sulfonate and 0-1.5 parts by mass of turpentine; in the mixed coal powder, the mass ratio of particles A, B and C is 6:1:3.

[0047] In some embodiments, the water-coal slurry is composed of the following components in parts by mass: 60-65 parts by mass of mixed coal powder, 35-40 parts by mass of water, 0.5-1.5 parts by mass of naphthalene sulfonate and 0-1.5 parts by mass of turpentine; in the mixed coal powder, the mass ratio of particles A, B and C is 6:1:3.

[0048] In some embodiments, the formula of the coal water slurry is Scheme 1 or Scheme 2:

[0049] Solution 1: The water-coal slurry is composed of 60 parts by mass of mixed coal powder, 39 parts by mass of water and 1 part by mass of pure naphthalene-based dry powder dispersant; the mixed coal powder is composed of particles A, particles B and particles C; the mass ratio of particles A, particles B and particles C is 6:1:3; particles A are Zhundong coal powder particles, and the D32 particle size range of particles A is 50-120 microns; particles B are Zhundong coal powder particles, and the D32 particle size range of particles B is 15-50 microns; particles C are Zhundong coal powder particles, and the D32 particle size range of particles C is 0.1-15 microns;

[0050] Option 2: The water-coal slurry is composed of 65 parts by mass of mixed coal powder, 34 parts by mass of water, 1 part by mass of pure naphthalene-based dry powder dispersant and 0.5 parts by mass of turpentine; the mixed coal powder is composed of particles A, particles B and particles C; the mass ratio of particles A, particles B and particles C is 6:1:3; the particles A are Zhundong coal powder particles, and the D32 particle size range of the particles A is 50-120 microns; the particles B are Zhundong coal powder particles, and the D32 particle size range of the particles B is 15-50 microns; the particles C are Shenfu coal powder particles, and the D32 particle size range of the particles C is 0.1-15 microns; the method of using the non-polar solvent is to evenly apply it on the surface of particle C.

[0051] In some embodiments, the coal water slurry is prepared by the following method, which includes the following steps: mixing mixed coal powder with water and a dispersant to obtain Zhundong coal water slurry; the mixed coal powder includes the particles A, the particles B and the particles C.

[0052] In some embodiments, the mixed coal powder is prepared by the following steps, which is method one or method two;

[0053] Method 1: mixing the particles A, B and C to obtain mixed coal powder;

[0054] Method 2: After mixing the particle C with the non-polar solvent, the mixture is mixed with the particle A and the particle B to obtain mixed coal powder.

[0055] In some embodiments, the particles A, B and C are obtained by crushing with a ball mill or a rod mill.

[0056] In some embodiments, the particles A, B and C are obtained by crushing and sieving using a ball mill or a rod mill.

[0057] The present invention also provides a method for preparing water-coal slurry, which comprises the following steps: mixing mixed coal powder with water and a dispersant to obtain Zhundong coal water-coal slurry; the raw materials, conditions and operations of the preparation method are as described in any of the above items.

[0058] The present invention also provides the use of any of the above-mentioned water-coal slurries in preparing synthesis gas.

[0059] In some embodiments, the effective components in the synthesis gas are ≥ 82%; the effective components are carbon monoxide and hydrogen.

[0060] In some embodiments, the carbon conversion of the syngas is ≥ 99%.

[0061] The positive progress of the present invention is that the Zhundong coal water slurry prepared by the preparation method of the present invention has high slurry concentration, high solid content, good stability, low viscosity, is convenient for pumping, storage and transportation, and is easy to atomize and gasify. Specifically, compared with the traditional pulping method:

[0062] (1) The coal water slurry of the present invention has a slurry concentration 5-10% higher than that of the existing Zhundong coal water slurry;

[0063] (2) The water-coal slurry of the present application is subjected to a shear rate of 100 s at 25 degrees Celsius. -1 Under the given conditions, the apparent viscosity is less than 1200 mPa·s, which is helpful for the development of water-coal slurry entrained-flow gasification technology using Zhundong coal as raw material;

[0064] (3) The water-coal slurry of the present application will not generate hard precipitation even if it is placed at room temperature and away from light for three days, and has high stability, which is conducive to storage and transportation. DETAILED DESCRIPTION

[0065] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples. The experimental methods in the following examples without specifying specific conditions are carried out according to conventional methods and conditions, or selected according to the product specifications.

[0066] Unless otherwise specified, the following measurement methods are used in the examples of this application:

[0067] For the determination of coal water slurry concentration (i.e. solid content), please refer to GB / T 18856.2-2002.

[0068] For the determination of viscosity of coal-water slurry, refer to GB / T 18856.4-2002.

[0069] The analysis method of raw coal is the national standard GB / T212-2008 "Coal Industry Analysis Method" and GB / T476-2001 "Elemental Analysis Method of Coal"

[0070] Example 1

[0071] 1. Raw materials: Zhundong coal

[0072] Symbols: moisture (M), ash (A), volatile matter (V) and fixed carbon (FC). Subscripts: as received (ar): the sample is in the state when the batch is received; dry (d): the sample is in a moisture-free state.

[0073] (1) The specific composition of Zhundong coal used in this example is shown in the following table.

[0074] .

[0075] (2) Pure naphthalene-based dry powder dispersant (Nanjing Nanda Environmental Protection Technology Co., Ltd., model NPDP).

[0076] (3) Water.

[0077] 2. Preparation of coal water slurry

[0078] (1) Grinding and crushing Zhundong coal through a ball mill;

[0079] (2) The crushed coal powder is passed through sieves of different mesh sizes to obtain Zhundong coal powder particles A with a D32 particle size range of 50-120 μm, Zhundong coal powder particles B with a D32 particle size range of 15-50 μm, and Zhundong coal powder particles C with a D32 particle size of 0.1-15 μm;

[0080] (3) mixing the obtained particles A, B and C in a mass ratio of 6:1:3 to obtain mixed coal powder;

[0081] (4) Mix the mixed coal powder, water and pure naphthalene-based dry powder dispersant in a mass ratio of 60:39:1 and stir for ten minutes to obtain Zhundong coal-water slurry.

[0082] 3. Product performance indicators

[0083] The properties of the prepared Zhundong coal-water slurry were tested:

[0084] (1) Appearance: Gray-black slurry. 25 degrees Celsius, at a shear rate of 100 s -1 Under certain conditions, the apparent viscosity is below 1200 mPa·s, with good fluidity and can be pumped;

[0085] (2) Solid content (wt%): 60; (determined by concentration test method)

[0086] (3) It can be stored stably at room temperature and away from light for 3 days without forming hard precipitation.

[0087] 4. Effect test

[0088] The prepared water-coal slurry is used in a multi-nozzle opposed water-coal slurry gasifier as described in patent application number 98110616.1 to prepare synthesis gas, the effective gas composition (carbon monoxide and hydrogen) is 82%, and the carbon conversion rate is above 99%.

[0089] Example 2

[0090] 1. Raw materials:

[0091] (1) Zhundong coal and Shenfu coal.

[0092] The specific composition of the Zhundong coal used in this embodiment is the same as that in Example 1.

[0093] The specific composition of the Shenfu coal used in this example is shown in the following table.

[0094] .

[0095] (2) Pure naphthalene-based dry powder dispersant.

[0096] (3) Turpentine (Shanghai Myrel Biochemical Technology Co., Ltd., model CAS 8006-64-2).

[0097] (4) Water.

[0098] 2. Preparation of coal water slurry

[0099] (1) Using different rod mills to crush Zhundong coal and Shenfu coal respectively, to obtain Zhundong coal powder particles A with a D32 particle size range of 50-120 μm, Zhundong coal powder particles B with a D32 particle size range of 15-50 μm, and Shenfu coal powder particles C with a D32 particle size of 0.1-15 μm;

[0100] (2) mixing the prepared particles C with turpentine in a mass ratio of 39:1, and stirring for ten minutes to obtain a particle C mixture;

[0101] (3) Mixing the mixture of particles A, particles B and particles C obtained in (1) and (2) to obtain mixed coal powder; the mass ratio of particles A, particles B and particles C is 6:1:3;

[0102] (4) The mixed coal powder obtained in (3), water and pure naphthalene-based dry powder dispersant were mixed in a mass ratio of 65:34:1 and stirred for ten minutes to obtain Zhundong coal-water slurry.

[0103] 3. Product performance indicators

[0104] The properties of the prepared Zhundong coal-water slurry were tested:

[0105] (1) Appearance: Gray-black slurry. 25 degrees Celsius, at a shear rate of 100 s -1Under certain conditions, the apparent viscosity is below 1200 mPa·s, with good fluidity and can be pumped;

[0106] (2) Solid content (wt%): 65;

[0107] (3) It can be stored stably at room temperature and away from light for 3 days without forming hard precipitation.

[0108] 4. Product Usage

[0109] The multi-nozzle opposed water-coal slurry gasifier described in patent application No. 98110616.1 is used to prepare synthesis gas, with effective gas components (carbon monoxide and hydrogen) of 85% and a carbon conversion rate of more than 99%.

[0110] Comparative Example 1

[0111] 1. Raw materials:

[0112] (1) Zhundong coal (the composition is the same as that of Example 1) and Shenfu coal (the composition is the same as that of Example 2).

[0113] (2) Sodium dodecylbenzene sulfonate (SDBS) dispersant.

[0114] (3) Silane non-polar solvent.

[0115] (4) Water.

[0116] 2. Preparation of coal water slurry

[0117] (1) Using different rod mills to crush Zhundong coal and Shenfu coal respectively, to obtain Zhundong coal powder particles A with a D32 particle size range of 50-120 μm, Zhundong coal powder particles B with a D32 particle size range of 15-50 μm, and Shenfu coal powder particles C with a D32 particle size of 0.1-15 μm;

[0118] (2) mixing the prepared particles C with turpentine in a mass ratio of 39:1, and stirring for ten minutes to obtain a particle C mixture;

[0119] (3) Mixing the mixture of particles A, particles B and particles C obtained in (1) and (2) to obtain mixed coal powder; the mass ratio of particles A, particles B and particles C is 6:1:3;

[0120] (4) The mixed coal powder obtained in (3), water and pure naphthalene-based dry powder dispersant were mixed in a mass ratio of 65:34:1 and stirred for ten minutes to obtain Zhundong coal-water slurry.

[0121] 3. Product performance indicators

[0122] The properties of the prepared Zhundong coal-water slurry were tested:

[0123] (1) Appearance: Gray-black slurry. 25 degrees Celsius, at a shear rate of 100 s -1 The apparent viscosity under the conditions was 2000 mPa·s, and the fluidity was poor;

[0124] (2) Solid content (wt%): 65%;

[0125] (3) After being placed at room temperature and away from light for 3 days, a hard precipitate was produced.

[0126] 4. Effect test

[0127] The prepared water-coal slurry is used in a multi-nozzle opposed water-coal slurry gasifier as described in patent application number 98110616.1 to prepare synthesis gas, with effective gas components (carbon monoxide and hydrogen) of 75% and a carbon conversion rate of 80%.

Claims

1. A coal-water slurry, characterized in that: The method comprises the following components in parts by mass: 55-65 parts by mass of mixed coal powder, 35-45 parts by mass of water and 0.01-3 parts by mass of a dispersant; The mixed coal powder comprises particles A, particles B and particles C; The particles A are Zhundong coal powder particles, and the D32 particle size of the particles A ranges from 50 to 120 microns; The particle B is Zhundong coal powder particle, and the particle size D32 of the particle B is in the range of 15-50 microns; The particles C are selected from one or more of Zhundong coal powder particles, Shenfu coal powder particles, petroleum coke, bituminous coal particles, anthracite particles, carbon balls, silicon dioxide or aluminum oxide, and the particle size D32 of the particles C is in the range of 0.1-15 microns; The mass fraction of the particle A accounts for more than 50% of the mixed coal powder, and the mass ratio of the particle A, particle B and particle C is 6: (0.7-1.3): (2-4); The dispersant is naphthalene sulfonate.

2. The coal-water slurry according to claim 1, characterized in that: It meets one or more of the following conditions: (1) The mass parts of the mixed coal powder is 60-65 mass parts; (2) The mass parts of water is 35-40 mass parts; (3) The mass part of the dispersant is 0.5-1.5 mass parts; (4) The particles C are selected from one or both of Zhundong coal powder particles and Shenfu coal powder particles; (5) The mass ratio of particles A, B and C is 6:1:3; (6) The water-coal slurry further comprises a non-polar solvent, wherein the non-polar solvent is one or both of turpentine and kerosene; (7) The dispersant is a naphthalene-based dry powder dispersant; (8) The solid content of the coal water slurry is 60-70wt%; (9) The apparent viscosity of the coal water slurry is less than 1200 mPas; (10) The Zhundong coal powder particles are obtained by grinding or crushing Zhundong coal; (11) The Shenfu coal powder particles are obtained by grinding or crushing Shenfu coal.

3. The coal-water slurry according to claim 2, characterized in that: It meets one or more of the following conditions: (1) The mass parts of the mixed coal powder is 60 mass parts or 65 mass parts; (2) The mass parts of water is 35 mass parts or 40 mass parts; (3) The mass part of the dispersant is 1 mass part; (4) The particles C are Shenfu coal powder particles; (5) The non-polar solvent is turpentine; (6) The non-polar solvent is used by evenly applying it on the surface of particle C; (7) The solid content of the coal water slurry is 60-65wt%; (8) The percentage of moisture in the Zhundong coal to the total mass of the Zhundong coal is 0.5-15wt%, such as 5-10wt%; for example, 7wt%; (9) The percentage of ash content of the Zhundong coal to the total mass of the dry Zhundong coal is 1-25wt%, such as 5-10wt%; for example, 7wt%; (10) The percentage of volatile matter in the Zhundong coal to the total mass of the dry Zhundong coal is 5-65wt%, such as 25-35wt%; for example, 34wt%; (11) The percentage of fixed carbon in the Zhundong coal to the total mass of the dry Zhundong coal is 50-75 wt%, such as 55-65 wt%; for example 59 wt%; (12) In the Zhundong coal, the mass of the C element accounts for 60-85wt% of the total mass of the dry Zhundong coal, such as 70-80wt%; for example, 74%; (13) In the Zhundong coal, the mass of the O element accounts for 7-20wt% of the total mass of the dry Zhundong coal, such as 12-18wt%; for example, 14%; (14) In the Zhundong coal, the mass of H element accounts for 0.5-15wt% of the total mass of the dry Zhundong coal, such as 3-4wt%; for example, 3.5%; (15) In the Zhundong coal, the mass of the N element accounts for 0.1-5wt% of the total mass of the dry Zhundong coal, such as 0.5-1.5 wt%; for example, 0.7%; (16) In the Zhundong coal, the mass of the S element accounts for 0.01-5 wt %, such as 0.2-0.8 wt % of the total mass of the dry Zhundong coal; for example, 0.5%; (17) The percentage of moisture in the Shenfu coal to the total mass of the Shenfu coal is 0.5-10wt%, such as 1-3wt%; for example, 2wt%; (18) The percentage of ash content of the Shenfu coal to the total mass of the dry Shenfu coal is 1-25 wt%, such as 5-10 wt%; for example, 6 wt%; (19) The percentage of volatile matter in the Shenfu coal to the total mass of the dry Shenfu coal is 10-55 wt%, such as 25-35 wt%; for example 31 wt%; (20) The percentage of fixed carbon in the Shenfu coal to the total mass of the dry Shenfu coal is 50-80 wt%, such as 58-68 wt%; for example 63 wt%; (21) In the Shenfu coal, the mass of the C element accounts for 60-85wt% of the total mass of the dry Shenfu coal, such as 70-80wt%; for example, 72%; (22) In the Shenfu coal, the mass of the O element accounts for 7-20wt% of the total mass of the dry Shenfu coal, such as 12-18wt%; for example, 13%; (23) In the Shenfu coal, the mass of H element accounts for 0.5-15wt% of the total mass of the dry Shenfu coal, such as 3-4wt%; for example, 4%; (24) In the Shenfu coal, the mass of the N element accounts for 0.5-5wt% of the total mass of the dry Shenfu coal, such as 1-3wt%; for example, 1.8%; (25) In the Shenfu coal, the mass of the S element accounts for 0.01-5wt% of the total mass of the dry Shenfu coal, such as 1-2wt%; for example, 1.5%.

4. The coal-water slurry according to claim 2, characterized in that: The water-coal slurry is composed of the following components in parts by mass: 55-65 parts by mass of the mixed coal powder, 35-45 parts by mass of the water, 0.01-3 parts by mass of the dispersant and 0-3 parts by mass of the non-polar solvent.

5. The coal-water slurry according to claim 2, characterized in that: The water-coal slurry comprises the following components in parts by mass: 60-65 parts by mass of mixed coal powder, 35-40 parts by mass of water, 0.5-1.5 parts by mass of naphthalene sulfonate and 0-1.5 parts by mass of turpentine; in the mixed coal powder, the mass ratio of particles A, particles B and particles C is 6:1:

3.

6. The coal-water slurry according to claim 2, characterized in that: The water-coal slurry consists of the following components in parts by mass: 60-65 parts by mass of mixed coal powder, 35-40 parts by mass of water, 0.5-1.5 parts by mass of naphthalene sulfonate and 0-1.5 parts by mass of turpentine oil; in the mixed coal powder, the mass ratio of the particles A, B and C is 6:1:

3.

7. The coal-water slurry according to claim 2, characterized in that: The formula of the water-coal slurry is scheme 1 or scheme 2: Solution 1: The water-coal slurry is composed of 60 parts by mass of mixed coal powder, 39 parts by mass of water and 1 part by mass of pure naphthalene-based dry powder dispersant; the mixed coal powder is composed of particles A, particles B and particles C; the mass ratio of particles A, particles B and particles C is 6:1:3; particles A are Zhundong coal powder particles, and the D32 particle size range of particles A is 50-120 microns; particles B are Zhundong coal powder particles, and the D32 particle size range of particles B is 15-50 microns; particles C are Zhundong coal powder particles, and the D32 particle size range of particles C is 0.1-15 microns; Option 2: The water-coal slurry is composed of 65 parts by mass of mixed coal powder, 34 parts by mass of water, 1 part by mass of pure naphthalene-based dry powder dispersant and 0.5 parts by mass of turpentine; the mixed coal powder is composed of particles A, particles B and particles C; the mass ratio of particles A, particles B and particles C is 6:1:3; the particles A are Zhundong coal powder particles, and the D32 particle size range of the particles A is 50-120 microns; the particles B are Zhundong coal powder particles, and the D32 particle size range of the particles B is 15-50 microns; the particles C are Shenfu coal powder particles, and the D32 particle size range of the particles C is 0.1-15 microns; the method of using the non-polar solvent is to evenly apply it on the surface of particle C.

8. The coal-water slurry according to claim 2, characterized in that: The coal water slurry is prepared by the following method, which includes the following steps: mixing mixed coal powder with water and a dispersant to obtain Zhundong coal water slurry; the mixed coal powder includes the particles A, the particles B and the particles C; Preferably, the mixed coal powder is prepared by the following steps, which is method one or method two; Method 1: mixing the particles A, B and C to obtain mixed coal powder; Method 2: After mixing the particle C with the non-polar solvent, the mixture is mixed with the particle A and the particle B to obtain a mixed coal powder; More preferably, the particles A, B and C are obtained by crushing with a ball mill or a rod mill; Alternatively, the particles A, B and C are obtained by crushing and sieving with a ball mill or a rod mill.

9. A method for preparing coal water slurry, characterized in that: It comprises the following steps: mixing mixed coal powder with water and dispersant to obtain Zhundong coal water slurry; the definitions and proportions of the mixed coal powder, water and dispersant are as described in any one of claims 1-7, and the conditions and operations of the preparation method are as described in claim 8.

10. Use of the coal water slurry according to any one of claims 1 to 8 in preparing synthesis gas; preferably, the synthesis gas satisfies one or more of the following conditions: (1) The effective components in the synthesis gas are ≥ 82%; the effective components are carbon monoxide and hydrogen; (2) The carbon conversion rate of the synthesis gas is ≥99%.