System and method for removing sodium from high-sodium coal based on triboelectric separation of maceral

Abstract

The invention belongs to the technical field of high-sodium coal sodium removal, and particularly relates to a high-sodium coal sodium removal system and method based on maceral triboelectric separation. The device comprises a crushing and screening area, a friction separation area and a surface modification area, the crushing and screening area comprises a feeding device, a drying device, a crushing device, a screening device and a screening device which are connected in sequence; the friction separation area comprises two sets of friction separation systems, namely crushing equipment, friction electrification equipment, high-voltage separation equipment, a negative electrode clean coal product collector, a positive electrode tail coal product collector and a circulating pipeline. According to the method, the dual purposes of sodium removal of the high-sodium coal and separation of the macerals are achieved, and high-quality raw materials are provided for subsequent combustion and deep processing.

Description

Technical Field

[0001] The invention belongs to the technical field of high-sodium coal desodiumization, and in particular relates to a high-sodium coal desodiumization system and method based on microscopic component friction electric separation. Background Art

[0002] The coal belongs to low-rank coal, which is a typical high-sodium and high-inert group coal (sodium in ash basis>2%, inert group content 40-80%), and has the advantages of low ash and sulfur, strong combustion stability and high chemical reaction activity. It is an excellent thermal coal and coal for coal chemical industry. As thermal coal, high-sodium coal will release a large amount of sodium-containing gaseous substances during the combustion process, which makes the boiler heating surface very easy to be shut down for slagging and slagging, and in severe cases, the boiler needs to be shut down for slagging. As chemical coal, the inert group content in coal is high and fluctuates greatly, which not only affects the efficiency of coal liquefaction, but also is not conducive to the stable operation of other coal chemical projects such as gasification.

[0003] Current methods for removing sodium from high-sodium coal mostly use wet removal methods such as hydrothermal removal to target the high sodium characteristics of coal, which requires the use of a large amount of water resources. For drip extraction where water resources are scarce, this method ignores the actual water use conditions of the application area. Moreover, it only relies on the high sodium characteristics, and does not start from the characteristics of the high inert group content of high-sodium coal, lacking comprehensive consideration of the subsequent deep processing of coal chemical industry.

[0004] Therefore, there is an urgent need for a high-sodium coal desodiumization system and method based on triboelectric separation of microscopic components to solve the above problems. Summary of the invention

[0005] In order to overcome the defects in the prior art, the present invention provides a high sodium coal desodiumization system and method based on microscopic component triboelectric separation. The present invention has the characteristics of being able to simultaneously achieve microscopic component separation and desodiumization effects, targeted treatment, and saving water resources, costs, and energy.

[0006] To achieve one of the above purposes, the present invention adopts the following technical solution:

[0007] A high-sodium coal desodiumization system based on frictional electric separation of microscopic components comprises a crushing and screening zone and a frictional separation zone, wherein the crushing and screening zone is connected to the frictional separation zone; the crushing and screening zone comprises a first screening device and a second screening device with different screening particle sizes, and the frictional separation zone comprises two sets of frictional separation systems, namely a first frictional separation system and a second frictional separation system, wherein the first frictional separation system comprises a second crushing device, a first frictional electrification device, a first high-voltage separation device and a negative electrode clean coal product collector connected in sequence, and the second frictional separation system comprises a third crushing device, a second frictional electrification device, a second high-voltage separation device and a positive electrode clean coal product collector connected in sequence; the discharge port of the first high-voltage separation device is respectively connected to the first circulation pipeline and the second high-voltage separation device; and the discharge port of the second high-voltage separation device is respectively connected to the second circulation pipeline and the first high-voltage separation device.

[0008] Preferably, the system further comprises a surface modification zone, the surface modification zone comprises two sets of surface modification systems, namely a first surface modification system and a second surface modification system, the first surface modification system comprises a first stirring barrel, a first filtering device and a first drying device connected in sequence, the first stirring barrel is connected to the first dosing device, the feed port of the first stirring barrel is connected to the second crushing device, and the discharge port of the first drying device is connected to the first friction electrification device;

[0009] The second surface modification system includes a second stirring barrel, a second filtering device and a second drying device connected in sequence. The second stirring barrel is connected to the second dosing device, the feed port of the second stirring barrel is connected to the third crushing device, and the discharge port of the second drying device is connected to the second friction electrification device.

[0010] Preferably, the crushing and screening area includes a feeding device, a drying device, a first crushing device, a first screening device and a second screening device connected in sequence, and the discharge port of the second screening device is respectively connected to the second crushing device and the third crushing device; the screening particle size of the first screening device is 25 mm, and the screening particle size of the second screening device is 1 mm.

[0011] Preferably, the first friction electrification device and the second friction electrification device include an electrification chamber, which is divided into a blank electrification chamber and a friction rod insertion electrification chamber. The blank electrification chamber is suitable for the case where the surface potential difference between the vitrinite group and the inertinite group in the feed coal is large (>0.45V) and the raw coal has poor cohesiveness. If the surface potential difference between the vitrinite group and the inertinite group in the feed coal is large (≤0.45V) and the cohesiveness is good, a friction rod insertion type is used to increase the number of collisions and efficiency; the blank electrification chamber is divided into a cylindrical electrification chamber and a cubic electrification chamber. The cylindrical electrification chamber is similar to the inlet and outlet pipe design and is suitable for the sorting of the vitrinite group and the inertinite group in the feed coal. The surface potential difference (>0.45V) and the amount of feed coal are small. The circular diameter of the cross section is ≤ the diameter of the connecting pipe. If there is no special need, it is the same as the diameter of the connecting pipe. If the collision intensity and number between coal particles need to be strengthened, the cross-sectional diameter can be appropriately reduced. The cubic shape is suitable for the sorting situation where the surface potential difference between the vitrinite and inertinite groups in the feed coal is large (>0.45V) but the feed coal amount is high; the friction rod insertion type charging chamber is divided into a cylindrical insertion charging chamber and a cubic insertion charging chamber; the cylindrical insertion charging chamber is to insert the friction rod perpendicular to the cylindrical surface along the diameter outside the cylindrical charging chamber, the ratio of the friction rod radius r to the charging chamber cross-sectional radius R is ≤1 / 4, and the center line spacing of adjacent friction rods D≥5r (r=friction rod radius); the radius ratio of the friction rod to the charging chamber is less than 1 / 4, which can ensure that the coal particles collide and rub with the friction rod surface while avoiding the excessively wide rod surface blocking the airflow movement, and also leave space for the mutual collision and friction between the coal particles in the charging chamber; the center line spacing of adjacent friction rods D≥5r, and the restriction greater than 5r can fully guarantee the friction effect of a single friction rod on the coal particles, and avoid the coal particle group from being diverted from both sides of a single friction rod and no longer merging and following The situation of friction rod surface collision and friction; the cube-shaped insertion charging chamber is to insert the friction rod perpendicular to the side of the cube outside the cubic charging chamber, and the friction rod arrangement includes equilateral triangle and broken line type; among them, in the equilateral triangle type, the height H of the equilateral triangle formed by three friction rods ≥ 1 / 4L (the length of the cube), so as to avoid the overly dense arrangement of friction rods hindering the transportation of coal flow, reducing the coal flow speed, and thus reducing the collision charging efficiency; in the broken line type, the right angle side d (parallel to the long side of the cube) of the right triangle formed by two adjacent friction rods is d ≥ 1 / 5L, and the other right angle side m (parallel to the short side of the cube) is 3 / 5M ≥ m ≥ 1 / 3M (the width of the cube), that is, it can avoid the overly dense arrangement of friction rods hindering the transportation of coal flow, and thus reducing the collision charging efficiency, and at the same time ensure that the spacing between the two rows of friction rods is in an appropriate range, which will not be too wide to cause low collision efficiency, nor too narrow to cause the coal flow beside the friction rod to not increase the number of collisions;

[0012] Preferably, the cube is inserted into the electrification chamber, and the cross-section of the friction rod is designed to be circular, equilateral triangle and rhombus; the radius of the circle r≤1 / 8M, the height of the equilateral triangle h≤1 / 4M, and the diagonal spacing of the rhombus n≤1 / 4M, so as to avoid the negative obstruction of the coal flow caused by the friction rod being over-regulated. In the equilateral triangle cross-section design, the coal flow direction is perpendicular to one side of a certain equilateral triangle, ensuring that the coal particles and the friction rod have the maximum collision angle; in the rhombus design, the coal flow direction is perpendicular to the two adjacent sides of the rhombus, ensuring that the coal particles and the friction rod have the maximum collision angle; among the three cross-section designs, the circular cross-section design is suitable for the case where the raw coal has low moisture and low cohesion, which can ensure the full collision of single particles; the equilateral triangle cross-section design is suitable for the case where the raw coal has low moisture but high cohesion, so that the larger plane impact and collision of the triangle can be used to break up the agglomerated particles; the rhombus cross-section design is suitable for the case where the raw coal has high moisture and high cohesion, and makes full use of the plane impact in four directions to make the particle group as loose as possible. For the two separation systems of mirror coal-rich and silk charcoal-rich raw coal, since mirror coal is brittle and non-adhesive, it is suitable for round friction rod design to ensure comprehensive collision friction. Silk charcoal is loose, fragile and has adhesiveness, so it is suitable for equilateral triangle and diamond friction rod design.

[0013] Preferably, the materials of the inner wall surface and the friction rod surface of the electrification chamber can be selected according to the surface potential difference of the microscopic components in the feed coal. When the surface potential difference is greater than 0.45V, the inner wall surface and the friction rod surface of the electrification chamber are made of pure metal materials with high hardness, such as stainless steel and copper; when the surface potential is less than or equal to 0.45V, the inner wall surface and the friction rod surface are made of materials with surface potentials in the middle value of the microscopic components, ensuring that the surfaces of the vitrinite-rich coal particles and the inertinite-rich coal particles carry charges of opposite polarities, and the inner wall surface and the friction rod surface of the electrification chamber are pure metal materials with high hardness or organic materials, such as polyethylene (PE).

[0014] To achieve the second of the above objectives, the present invention provides a method for removing sodium from high-sodium coal based on triboelectric separation of microscopic components, comprising the following steps:

[0015] S1: Dry the raw high-sodium coal and crush it to less than 25mm, and then screen the crushed raw coal into A raw vitrinite-rich coal and B raw filament-rich coal; due to the different properties of the macroscopic and microscopic components of coal, vitrinite (mainly composed of the microscopic component vitrinite) and filament-rich coal (mainly composed of the microscopic component inertite), vitrinite is brittle and easy to break into angular small pieces, while filament-rich coal has many pores, is loose and easy to break into powder. After preliminary crushing, screening and grading, the raw high-sodium coal can be divided into A raw vitrinite-rich coal (particle size 1-25mm) and B raw filament-rich coal (particle size 0-1mm);

[0016] S2: A mirror-rich raw coal and B silk-rich raw coal are respectively sent to the first friction separation system and the second friction electric separation system to be crushed to less than 150 μm, and then subjected to high-voltage separation after friction charging;

[0017] S3: After the A vitrinite-rich raw coal enters the first friction separation system, the vitrinite-rich coal particles are enriched in the A negative electrode clean coal, and the inertinite-rich coal particles are enriched in the A positive electrode tail coal. The A negative electrode clean coal is collected, and the A positive electrode tail coal is not collected and directly sent to the second friction separation system for separation;

[0018] S4: After the B filamentous carbon raw coal enters the second friction separation system, the vitrinite-rich coal particles are enriched in the B negative electrode clean coal, and the inertinite-rich coal particles are enriched in the B positive electrode tail coal. The B positive electrode tail coal is collected, and the B negative electrode clean coal is not collected and directly sent to the first friction separation system for separation;

[0019] S5: The final collected negative electrode clean coal A is a low-sodium vitrinite-rich product, and the positive electrode tail coal B is a high-sodium inertinite-rich product.

[0020] Preferably, in step 1, A vitrinite-rich raw coal has a particle size of 1-25 mm, and B fusinite-rich raw coal has a particle size of 0-1 mm; the crushing particle size is determined according to the content change law of vitrinite and inertinite in different particle sizes; the content distribution of microscopic components in high-sodium raw coal and raw coal samples crushed and screened to different particle sizes (>50 mm, 50-25 mm, 25-13 mm, 13-6 mm, 6-3 mm, 3-1 mm, 1-0.5 mm, <0.5 mm) are compared.

[0021] Preferably, in step 2, the high-sodium coal raw coal is subjected to surface modification treatment before entering the first friction separation system and the second friction electric separation system: when the surface potential difference between the two is greater than 0.45V, no surface modification treatment is added; when the surface potential difference between the two is less than or equal to 0.45V, surface modification treatment is performed.

[0022] Preferably, the surface modifier for surface modification treatment is one of light diesel oil, kerosene, ammonia water and ethanol. When the surface potential difference of the hand-selected vitrinite group and inertinite group enriched samples in the high sodium coal raw coal is 0.45V, the surface modification reagents of A vitrinite-rich raw coal and B filament-rich raw coal are both light diesel oil. When the surface potential difference between the two is less than 0.45V, ethanol or kerosene is used for A vitrinite-rich raw coal, and ammonia water is used for B filament-rich raw coal; the surface modifier dosage of A and B raw coal is: 0.8-1.2kg / t.

[0023] The advantages of the present invention are:

[0024] (1) The friction sorting process for separating microscopic components of high-sodium coal in the present invention is divided into two parallel sorting systems A and B, which not only reduces the processing pressure of a single system, but also can pre-enrich vitrinite (a macroscopic coal rock component rich in vitrinite) and fusinite (a macroscopic coal rock component rich in inertinite) and carry out targeted sorting. The vitrinite-rich raw coal will obtain a vitrinite-rich low-sodium product (negative clean coal) with further enrichment of vitrinite in its first friction sorting system, while the positive tail coal with relatively enriched inertinite is directly sent to the B friction sorting system for special sorting of fusinite-rich raw coal to further enrich the inertinite. Similarly, the fusinite-rich raw coal will obtain an inertinite-rich high-sodium product (positive tail coal) with further enrichment of inertinite in its B friction sorting system, while the negative clean coal with relatively enriched vitrinite is directly sent to the first friction sorting system for special sorting of vitrinite-rich raw coal to further enrich the vitrinite, achieving the dual purpose of removing sodium from high-sodium coal and separating microscopic components, providing high-quality raw materials for subsequent combustion and deep processing.

[0025] (2) The present invention has the characteristics of clear method principle, simultaneous separation of microscopic components and sodium removal, targeted treatment, and saving of water resources, cost and energy.

[0026] (3) The present invention measures the surface potential of the microscopic component enriched sample of the high sodium coal raw coal in advance, and decides whether to add the surface modification link according to the surface potential difference between the inertin group and the vitrinite group. If the surface potential difference between the two is greater than 0.45V, the surface modification treatment link is not added; if the difference is ≤0.45V, the surface modification treatment link is added. At the same time, different surface modification agents are used for the vitrinite-rich coal and the fusinite-rich coal raw coal in the surface modification link, and the specific situation is specifically limited, and targeted treatment is carried out to increase the modification effect and improve the sorting efficiency.

[0027] (4) The friction electrification equipment of the two friction sorting systems of the present invention is designed differently. The electrification chamber and friction rod design are customized according to the characteristics of high-sodium coal or even mirror-rich coal and charcoal-rich coal, so as to improve the friction electrification efficiency and sorting effect.

[0028] (5) The main occurrence form of sodium in high-sodium coal is water-soluble sodium, which is easily distributed in the inerting group with well-developed pores and has a strong distribution and occurrence correlation with the inerting group. Therefore, sodium removal can be carried out by separating the microscopic components, achieving the dual effects of microscopic component separation and sodium removal. For areas with a lack of water resources and facing serious groundwater over-exploitation problems, the use of electrostatic dry separation technology to separate microscopic components for sodium removal complements the strategic development background of the local coal-fired power industry and the special sorting environment of drought and water shortage. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Schematic diagram of the system of the present invention.

[0030] Figure 2 It is a flow chart of the present invention.

[0031] Figure 3 It is a schematic diagram of the friction electrification device of the present invention - the electrification chamber.

[0032] Figure 4 It is a schematic diagram of the arrangement of the cubic ② friction rod insertion type in the friction electrification device of the present invention - the electrification chamber design, and the cubic ② friction rod insertion type friction rod arrangement (taking the circular friction rod as an example).

[0033] Figure 5 It is a schematic cross-sectional view of the cubic-shaped ② friction rod insertion type in the friction electrification device of the present invention - the electrification chamber design, and the cross-sectional design of the cubic-shaped ② friction rod insertion type friction rod (taking the broken line arrangement as an example).

[0034] The meanings of the symbols in the figure are as follows:

[0035] 1-feeding equipment, 2-drying equipment, 3-first crushing equipment, 4-first screening equipment, 5-second screening equipment, 6A-second crushing equipment, 6B-third crushing equipment, 7A-first friction electrification equipment, 7B-second friction electrification equipment, 8A-first high-pressure sorting equipment, 8B-second high-pressure sorting equipment, 9A-negative clean coal product collector, 9B-positive clean coal product collector, 10-first circulation pipeline, 11-second circulation pipeline, 12A-first stirring barrel, 12B-second stirring barrel, 13A-first dosing equipment, 13B-second dosing equipment, 14A-first filtering equipment, 14B-second filtering equipment, 15A-first drying equipment, 15B-second drying equipment. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present invention.

[0037] like Figure 1-5 As shown, a high sodium coal desodiumization system based on frictional electrostatic separation of microscopic components includes a crushing and screening zone, a frictional separation zone and a surface modification zone.

[0038] The crushing and screening area includes a feeding device 1, a drying device 2, a first crushing device 3, a first screening device 4 and a second screening device 5. The feed port of the drying device 2 is connected to the feeding device 1, and the discharge port is connected to the first crushing device 3; the feed port of the first crushing device 3 is connected to the discharge port of the drying device 2, and the discharge port is connected to the first screening device 4; the feed port of the first screening device 4 is connected to the discharge port of the first crushing device 3, the discharge port 4I is connected to the feed port of the first crushing device 3, and the discharge port 4II is connected to the feed port of the second screening device 5; the feed port of the second screening device 5 is connected to the discharge port 4II of the first screening device 4, the discharge port 5I is connected to the feed port of the friction separation area crushing device 6A, and the discharge port 5II is connected to the feed port of the friction separation area crushing device 6B.

[0039] The friction sorting area includes two sets of friction sorting systems: crushing equipment 6A and 6B, friction electrification equipment 7A and 7B, high-voltage sorting equipment 8A and 8B, negative electrode clean coal product collector 9A and positive electrode tail coal product collector 9B, and circulation pipelines 10 and 11. Take a single set of sorting system as an example: the feed port of the crushing equipment 6A is connected to the discharge port 5I of the second screening equipment 5 in the crushing and screening area, and the discharge port is connected to the feed port of the friction electrification equipment 7A. The feed port of the friction electrification device 7A is connected to the discharge port of the crushing equipment 6A, and the discharge port is connected to the feed port of the high-voltage sorting equipment 8A. The feed port of the high-voltage sorting equipment 8A is connected to the discharge port of the friction electrification equipment 7A, and the discharge port 8AI is connected to the circulation pipeline 10, and the discharge port 8AII is connected to the negative electrode clean coal product collector 9A. The two ends of the circulation pipeline 10 are respectively connected to the discharge port 8AI of the high-voltage sorting equipment 8A and the feed port of the high-voltage sorting equipment 8B. The connection sequence of the corresponding other set of sorting systems is the same, except that the discharge port 8BI of the high-pressure sorting equipment 8B is connected to the positive electrode tail coal product collector 9B, and the discharge port 8BII is connected to the circulation pipeline 11.

[0040] The surface modification area is optional and includes 2 sets of surface modification systems: stirring barrels 12A and 12B, dosing equipment 13A and 13B, filtering equipment 14A and 14B, and drying equipment 15A and 15B. If it is necessary to use it, take a single set of surface modification system as an example: the feed port of stirring barrel 12A is connected to the crushing equipment 6A in the friction separation area, and the discharge port is connected to the feed port of filtering equipment 14A. The discharge port of dosing equipment 13A is connected to the feed port of stirring barrel 12A. The feed port of filtering equipment 14A is connected to the discharge port of stirring barrel 12A, and the discharge port is connected to drying equipment 15A. The feed port of drying equipment 15A is connected to the discharge port of filtering equipment 14A, and the discharge port is connected to the feed port of friction electrification equipment 7A in the friction separation area. The connection order of the corresponding other set of surface modification systems is the same.

[0041] Furthermore, the areas and equipment are connected by pipelines.

[0042] Further, there is no specific limitation requirement for the feeding device 1, the drying device 2, 15A and 15B, the first crushing device 3, 6A and 6B, the first screening device 4 and 5, the dosing device 13A and 13B, and the filtering device 14A and 14B. The conventional feeding, drying, crushing and screening equipment in the field of mineral processing can be used, and only needs to be selected according to the properties of the coal and the specific feed amount. The screening particle size of the first screening device 4 is 25 mm, and the screening particle size of the second screening device 5 is 1 mm.

[0043] Furthermore, the friction electrification devices 7A and 7B are electrification chamber designs, and the electrification chamber designs are divided into ① blank type and ② friction rod insertion type. The blank type is suitable for the case where the surface potential difference between the vitrinite group and the inertinite group in the feed coal is large (>0.45V) and the raw coal has poor cohesiveness. If the surface potential difference between the vitrinite group and the inertinite group in the feed coal is large (≤0.45V) and the cohesiveness is good, the friction rod insertion type is used to increase the number of collisions and efficiency.

[0044] Furthermore, the electrification chamber design ① Blank type can be divided into cylindrical and cubic designs. The cylindrical electrification chamber is similar to the design of the inlet and outlet pipes, and is suitable for sorting situations where the surface potential difference between the vitrinite and inertinite groups in the feed coal is large (>0.45V) and the amount of feed coal is small. The circular diameter of the cross section is ≤ the diameter of the connecting pipe. If there is no special requirement, it is the same as the diameter of the connecting pipe. If the intensity and number of collisions between coal particles need to be enhanced, the cross-sectional diameter can be appropriately reduced. The cubic shape is suitable for sorting situations where the surface potential difference between the vitrinite and inertinite groups in the feed coal is large (>0.45V) but the amount of feed coal is high.

[0045] Furthermore, the electrification chamber design ② friction rod insertion type can be divided into cylindrical insertion and cubic insertion design. The cylindrical insertion is specifically to insert the friction rod perpendicular to the cylindrical surface along the diameter outside the cylindrical electrification chamber, the ratio of the friction rod radius r to the electrification chamber cross-sectional radius R is ≤1 / 4, and the center line spacing of adjacent friction rods D≥5r (r=friction rod radius); the radius ratio of the friction rod to the electrification chamber less than 1 / 4 can ensure that the coal particles collide and rub with the friction rod surface while avoiding the excessively wide rod surface blocking the air flow movement, and also leave space for the mutual collision and friction between the coal particles in the electrification chamber; the center line spacing of adjacent friction rods D≥5r, and the restriction of greater than 5r can fully guarantee the friction effect of a single friction rod on the coal particles, and avoid the situation where the coal particle group is diverted from both sides of a single friction rod and no longer converges to collide and rub with the subsequent friction rod surface.

[0046] Furthermore, in the cubic insertion design of the electrification chamber design ② friction rod insertion type, the cubic insertion is specifically to insert the friction rod vertically into the side of the cube outside the cubic electrification chamber. There are two types of friction rod arrangement: equilateral triangle and broken line. In the equilateral triangle, the height H of the equilateral triangle composed of three friction rods is ≥1 / 4L (the length of the cube), so as to avoid the overly dense arrangement of friction rods hindering the transportation of coal flow, reducing the coal flow speed, and thus reducing the collision charging efficiency. In the broken line, the right angle side d (parallel to the long side of the cube) of the right triangle composed of two adjacent friction rods needs to be d≥1 / 5L, and the other right angle side m (parallel to the short side of the cube) needs to be 3 / 5M≥m≥1 / 3M (the width of the cube), that is, it can avoid the overly dense arrangement of friction rods hindering the transportation of coal flow, thereby reducing the collision charging efficiency, and at the same time ensure that the spacing between the two rows of friction rods is in an appropriate range, which will not be too wide to cause low collision efficiency, nor too narrow to cause the coal flow beside the friction rod to not increase the number of collisions.

[0047] Furthermore, in the cubic insertion design of the electrification chamber design ② friction rod insertion type, the friction rod cross-section design is designed into three types: circular, equilateral triangle and rhombus. The circular radius r≤1 / 8M, the equilateral triangle height h≤1 / 4M, and the rhombus diagonal spacing n≤1 / 4M, to avoid the negative obstruction of the coal flow caused by the friction rod being over-regulated. In the equilateral triangle cross-section design, the coal flow direction must be perpendicular to a certain side of the equilateral triangle to ensure that the coal particles and the friction rod have the maximum collision angle. In the rhombus design, the coal flow direction must be perpendicular to the two adjacent sides of the rhombus to ensure that the coal particles and the friction rod have the maximum collision angle. Among the three cross-section designs, the circular cross-section design is suitable for the case where the raw coal has low moisture and low cohesion, which can ensure the full collision of single particles; the equilateral triangle cross-section design is suitable for the case where the raw coal has low moisture but high cohesion, so that the larger plane impact and collision of the triangle can be used to break up the agglomerated particles; the rhombus cross-section design is suitable for the case where the raw coal has high moisture and high cohesion, and the plane impact in four directions is fully utilized to make the particle group as loose as possible. For the two separation systems of mirror coal-rich and silk charcoal-rich raw coal, since mirror coal is brittle and non-adhesive, it is suitable for round friction rod design to ensure comprehensive collision friction. Silk charcoal is loose, fragile and has adhesiveness, so it is suitable for equilateral triangle and diamond friction rod design.

[0048] Furthermore, the materials of the inner wall surface and the friction rod surface of the electrification chamber can be selected according to the surface potential difference of the microscopic components in the feed coal. When the surface potential difference is greater than 0.45V, a pure metal material with high hardness such as stainless steel and copper can be selected to make the inner wall surface and the friction rod surface; when the surface potential is less than or equal to 0.45V, a material with a surface potential in the middle value of the microscopic components can be selected to make the inner wall surface and the friction rod surface, so as to ensure that the surfaces of the vitrinite-rich coal particles and the inertinite-rich coal particles carry charges of opposite polarities, and the material can be selected as an organic material such as polyethylene (PE).

[0049] A method for removing sodium from high-sodium coal based on triboelectric separation of microscopic components comprises the following steps:

[0050] 1: Dry the high-sodium raw coal and crush it to less than 25mm, and then screen the crushed raw coal into two particle sizes: A (1-25mm) and B (0-1mm). Due to the different properties of the macroscopic and microscopic components of coal, vitrinite (mainly composed of the microscopic component vitrinite) and fusinite (mainly composed of the microscopic component inertite), vitrinite is brittle and easy to break into angular small pieces, while fusinite has many pores, is loose and easy to break into powder. After preliminary crushing, screening and grading, the high-sodium raw coal can be divided into A vitrinite-rich raw coal (particle size 1-25mm) and B fusinite-rich raw coal (particle size 0-1mm);

[0051] 2: Send A mirror-rich raw coal and B silk-rich raw coal into two friction separation systems A and B respectively, and then crush them to less than 150μm, and then carry out high-voltage separation after friction charging;

[0052] 3: After the A vitrinite-rich raw coal enters the first friction separation system, the vitrinite-rich coal particles are enriched in the A negative electrode clean coal, and the inertinite-rich coal particles are enriched in the A positive electrode tail coal. The A negative electrode clean coal is collected, and the A positive electrode tail coal is not collected and directly sent to the second friction separation system for separation;

[0053] 4: After the B filamentous carbon raw coal enters the B friction separation system, the vitrinite-rich coal particles are enriched in the B negative electrode clean coal, and the inertinite-rich coal particles are enriched in the B positive electrode tail coal. The B positive electrode tail coal is collected, and the B negative electrode clean coal is not collected and directly sent to the first friction separation system for separation;

[0054] 6: The final collected A negative electrode clean coal is a low-sodium vitrinite-rich product, and B positive electrode tail coal is a high-sodium inertite-rich product.

[0055] Furthermore, the high-sodium raw coal in step 1 is dried in a blast drying device at a drying temperature of 80° C. The high-sodium coal in the Zhundong area is low-rank coal (non-sticky coal, weakly sticky coal, etc.) with a high water content, which is easy to affect the sorting effect.

[0056] Furthermore, in step 1, the crushing particle size of the high-sodium raw coal is set to 25mm and 1mm respectively. The crushing particle size is determined according to the content variation law of the vitrinite and inertinite in different particle sizes. The distribution of the content of macerals in the high-sodium raw coal and the raw coal samples crushed and screened to different particle sizes (>50mm, 50-25mm, 25-13mm, 13-6mm, 6-3mm, 3-1mm, 1-0.5mm, <0.5mm) is compared. Except that the inertinite content in the raw coal samples of 1-0.5mm and <0.5mm particle sizes is higher than that in the high-sodium raw coal, the vitrinite content in the raw coal samples of the remaining particle sizes is higher than that in the high-sodium raw coal. It shows that the particle size classification has a certain enrichment effect on the macerals, and the vitrinite is relatively enriched in the part above 1mm, and the inertinite is enriched in the part below 1mm. Therefore, the present invention sets the two-step crushing particle size to 25mm and 1mm. 25mm is for a certain crushing of the raw coal, and 1mm is to define the particle size enrichment boundary of the vitrinite group and the inertinite group. 1-25mm is the relative enrichment particle size of the vitrinite group, and the raw coal of this particle size is A-rich vitrinite raw coal (particle size 1-25mm); 1mm is the relative enrichment particle size of the inertinite group, and the raw coal of this particle size is B-rich charcoal raw coal (particle size 0-1mm);

[0057] Furthermore, the microscopic components of the high-sodium raw coal were quantitatively determined, and the vitrinite and inertinite enriched samples (purity ≥ 90%) were hand-selected, and the surface potential values ​​were measured using an atomic force microscope (AFM).

[0058] Further, according to the difference in surface potential values ​​of the hand-selected vitrinite group and inertinite group enriched samples of the high-sodium raw coal, a surface modification treatment step can be selectively added before the A and B raw coals enter the triboelectric separation system in step 2: when the surface potential difference between the two is greater than 0.45V, the surface modification treatment step is not added; when the surface potential difference between the two is less than or equal to 0.45V, the surface modification treatment step is added;

[0059] Furthermore, the surface modifiers are light diesel oil, kerosene, ammonia water and ethanol. When the surface potential difference of the hand-selected vitrinite group and inertinite group enriched samples in the high sodium raw coal is 0.45V, the surface modification reagents of A vitrinite-rich raw coal and B filament-rich raw coal are both light diesel oil. When the surface potential difference between the two is less than 0.45V, ethanol or kerosene is used for A vitrinite-rich raw coal, and ammonia water is used for B filament-rich raw coal;

[0060] Furthermore, the amount of surface modifier used for raw coals A and B is 0.8-1.2 kg / t. Since the specific surface area of ​​silk charcoal is greater than that of mirror coal, the amount of surface modifier used for raw coal B rich in silk charcoal is controlled to be greater than that for raw coal A rich in mirror coal in actual operation.

[0061] Example 1

[0062] A method for removing sodium from high-sodium coal based on triboelectric separation of microscopic components comprises the following steps:

[0063] The high-sodium raw coal first passes through the feeding equipment and enters the drying equipment. After drying at 80℃, it enters the crushing equipment for preliminary crushing. After crushing, it enters the screening equipment for 25mm particle size screening. Large coal samples above 25mm are returned to the crushing equipment for further crushing. Coal samples below 25mm enter the lower screening equipment for 1mm particle size screening. The 1-25mm vitrinite-rich raw coal enters the crushing equipment of the first friction sorting system and is crushed again to less than 150mm. The vitrinite-rich raw coal below 150μm enters the friction charging equipment for friction charging and then enters the high-pressure sorting equipment for sorting. The surface of the vitrinite-rich coal particles is easy to lose charge and become positively charged, and are enriched on the negative electrode, and are collected as the negative electrode clean coal product-low sodium vitrinite-rich product. The surface of the coal particles relatively rich in inertinite is easy to get charge and become negatively charged, and are easily enriched on the positive electrode and are directly sent to the high-pressure sorting equipment of the B friction sorting system for sorting. Correspondingly, the fusinite-rich raw coal with a size of less than 1 mm enters the crushing equipment of the B friction sorting system and is crushed again to less than 150 mm. The fusinite-rich raw coal with a size of less than 150 mm enters the friction charging equipment for friction charging and then enters the high-voltage sorting equipment for sorting. The surface of the coal particles rich in the inertinite group is easy to get a charge and become negatively charged, and is enriched on the positive electrode and collected as the positive electrode tail coal product - a high-sodium inertinite-rich product. The surface of the coal particles rich in the vitrinite group is relatively easy to lose a charge and become positively charged, and is easily enriched on the negative electrode and is directly sent to the high-voltage sorting equipment of the first friction sorting system for sorting.

[0064] In addition, the microscopic components of high-sodium raw coal are quantitatively determined, and the vitrinite and inertinite enriched samples (purity ≥ 90%) are hand-selected, and the surface potential value is measured using an atomic force microscope (AFM). When the surface potential difference between the two is ≤ 0.45V, a surface modification treatment step is added: A vitrinite-rich raw coal and B silk-rich raw coal are respectively sent to the A and B friction sorting systems, and then crushed to less than 150μm, and then sent to the mixing barrel to add surface modifier for modification, and then sent to the filtering equipment to filter out the agent and enter the drying equipment, and then connected to the friction electrification equipment for subsequent sorting after drying.

[0065] Example 2

[0066] It is used for separation and sodium removal of microscopic components of Zhundong high-sodium coal. The surface potential of the raw coal vitrinite enriched sample is -0.05V, and the surface potential of the inertinite enriched sample is 0.42V. The surface potential difference between the two is 0.47V>0.45V, and no surface modification link is used.

[0067] like Figure 1As shown, the high-sodium coal in the Jungar area is dried and crushed to less than 25 mm, the high-sodium coal below 25 mm is screened at 1 mm, and the raw coal with a particle size of 1-25 mm is sent to the first friction sorting system as mirror-rich coal, and the raw coal with a particle size of less than 1 mm is sent to the B friction sorting system as silk-rich charcoal. The vitrinite-rich raw coal enters the first friction sorting system, enters the friction charging equipment (the charging chamber is blank, circular in design, without friction rods, and the inner wall material of the charging chamber is stainless steel), and is sent to the high-voltage sorting equipment after friction charging. The positive electrode product is collected as a vitrinite-rich low-sodium product, and the negative electrode product is directly connected to the feed port of the high-voltage sorting equipment in the B friction sorting system for cyclic sorting; the silk charcoal-rich raw coal enters the B friction sorting system, enters the friction charging equipment (the charging chamber friction rod is inserted, cubic in design, folded line, diamond-shaped friction rod, and the inside of the charging chamber and the friction rod surface are made of stainless steel), and is sent to the high-voltage sorting equipment after friction charging. The negative electrode product is collected as an inert group-rich high-sodium product, and the positive electrode product is directly connected to the feed port of the high-voltage sorting equipment of the first friction sorting system for cyclic sorting.

[0068] The vitrinite content in the vitrinite-rich raw coal is high, and it is brittle and difficult to bond. In addition, the high-sodium raw coal belongs to the high-inert group coal, and the input amount of the vitrinite-rich raw coal is small, so the triboelectric charging equipment adopts a blank circular design of the charging chamber. In addition, the surface potential difference between the vitrinite group and the inertinite group enriched samples of the raw coal is large, so the friction rod design is no longer added to the charging chamber. At the same time, metal is used as the internal material, which is strong and wear-resistant, and organic materials with surface potentials between the vitrinite and inertinite components are no longer considered.

[0069] The charcoal-rich raw coal has a high charcoal content, is loose and fragile, and is easy to stick together. In addition, the high-sodium raw coal is a high-inert coal, and the charcoal-rich raw coal has a large input, so the friction electrification equipment adopts a cubic design of the electrification chamber. Although the surface potential difference between the mirror and inert components of the raw coal is large, the electrification chamber still chooses to use a friction rod insertion type because the charcoal-rich raw coal is easy to stick together. The friction rod adopts a diamond cross-section. The laboratory coal sorting capacity is limited, and the friction rod arrangement adopts a relatively loose broken line type.

[0070] The raw coal of Zhundong high-sodium coal has an ash content of 4.05%, a sodium content of 3200μg / g, a vitrinite content of 43.00%, and an inertinite content of 66.50% (without mineral basis); the vitrinite-rich low-sodium product obtained by sorting has a yield of 38.35%, an ash content of 3.44%, a sodium content of 2441μg / g, a vitrinite content of 59.00%, and an inertinite content of 41.00% (without mineral basis); the inertinite-rich high-sodium product has a yield of 61.53%, an ash content of 4.50%, a sodium content of 3907μg / g, a vitrinite content of 24.00%, and an inertinite content of 76.00% (without mineral basis). The vitrinite-rich low-sodium product has a high vitrinite content (close to 60%) and a low sodium content, and can be used as coal for combustion and liquefaction. The inertinite-rich high-sodium product has an inertinite content of >75%, and can be used for pyrolysis, gasification, and the production of activated carbon and graphite materials, etc.

[0071] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A high sodium coal desodiumization system based on triboelectric separation of microscopic components, characterized in that: The invention comprises a crushing and screening area and a friction separation area, wherein the crushing and screening area is connected to the friction separation area; the crushing and screening area comprises a first screening device (4) and a second screening device (5) having different screening particle sizes; the friction separation area comprises two sets of friction separation systems, namely a first friction separation system and a second friction separation system; the first friction separation system comprises a second crushing device (6A), a first friction electrification device (7A), a first high-pressure separation device (8A) and a negative electrode clean coal product collector (9A) connected in sequence; the second friction separation system comprises a third crushing device (6B), a second friction electrification device (7B), a second high-pressure separation device (8B) and a positive electrode clean coal product collector (9B) connected in sequence; the discharge port of the first high-pressure separation device (8A) is respectively connected to the first circulation pipeline (10) and the second high-pressure separation device (8B); the discharge port of the second high-pressure separation device (8B) is respectively connected to the second circulation pipeline (11) and the first high-pressure separation device (8A).

2. A high sodium coal desodiumization system based on microscopic component friction electric separation according to claim 1, characterized in that: The system also includes a surface modification zone, which includes two surface modification systems, namely a first surface modification system and a second surface modification system. The first surface modification system includes a first stirring barrel (12A), a first filtering device (14A) and a first drying device (14A)(2) which are connected in sequence. The first stirring barrel (12A) is connected to a first dosing device (13A). The feed port of the first stirring barrel (12A) is connected to a second crushing device (6A). The discharge port of the first drying device (14A)(2) is connected to a first friction electrification device (7A). The second surface modification system includes a second stirring barrel (12B), a second filtering device (14B) and a second drying device (15B)(2) which are connected in sequence. The second stirring barrel (12B) is connected to the second dosing device (13B), the feed port of the second stirring barrel (12B) is connected to the third crushing device (6B), and the discharge port of the second drying device (15B)(2) is connected to the second friction electrification device (7B).

3. A high sodium coal desodiumization system based on microscopic component triboelectric separation according to claim 1, characterized in that: The crushing and screening section comprises a feeding device (1), a drying device (2), a first crushing device (3), a first screening device (4) and a second screening device (5) which are connected in sequence, and the discharge port of the second screening device (5) is respectively connected to the second crushing device (6A) and the third crushing device (6B); the screening particle size of the first screening device (4) is 25 mm, and the screening particle size of the second screening device (5) is 1 mm.

4. A high sodium coal desodiumization system based on microscopic component triboelectric separation according to claim 1, characterized in that: The first friction electrification device (7A) and the second friction electrification device (7B) comprise electrification chambers, which are divided into blank electrification chambers and friction rod insertion electrification chambers; the blank electrification chambers are divided into cylindrical electrification chambers and cubic electrification chambers; the friction rod insertion electrification chambers are divided into cylindrical insertion electrification chambers and cubic insertion electrification chambers; The cylindrical insertion charging chamber is to insert the friction rod perpendicular to the cylindrical surface along the diameter outside the cylindrical charging chamber, the ratio of the friction rod radius r to the charging chamber cross-sectional radius R is ≤1 / 4, and the center line spacing D of adjacent friction rods is ≥5r (r=friction rod radius); the cube-shaped insertion charging chamber is to insert the friction rod perpendicular to the cube side outside the cubic charging chamber, and the friction rod arrangement includes equilateral triangle type and broken line type; among which, in the equilateral triangle type, the height H of the equilateral triangle formed by three friction rods is ≥1 / 4L; in the broken line type, the right angle side d of the right triangle formed by two adjacent friction rods is d≥1 / 5L, and the other right angle side m is 3 / 5M≥m≥1 / 3M.

5. A high sodium coal desodiumization system based on microscopic component friction electric separation according to claim 4, characterized in that: The cube is inserted into the electrification chamber, and the cross-section of the friction rod is designed to be circular, equilateral triangle and rhombus; the radius of the circle r≤1 / 8M, the height of the equilateral triangle h≤1 / 4M, the diagonal spacing of the rhombus n≤1 / 4M, and in the equilateral triangle cross-section design, the coal flow direction is perpendicular to a certain side of a certain equilateral triangle; in the rhombus design, the coal flow direction is perpendicular to two adjacent sides of the rhombus.

6. A high sodium coal desodiumization system based on microscopic component triboelectric separation according to claim 5, characterized in that: When the surface potential difference is greater than 0.45V, the inner wall surface of the electrification chamber and the friction rod surface are made of pure metal materials with high hardness; when the surface potential is less than or equal to 0.45V, the inner wall surface of the electrification chamber and the friction rod surface are made of pure metal materials with high hardness or organic materials.

7. A method for removing sodium from high sodium coal based on triboelectric separation of microscopic components as claimed in any one of claims 1 to 6, characterized in that: The steps include: S1: drying and crushing the high sodium coal into less than 25 mm, and then screening the crushed coal into A mirror-rich coal and B silk-rich coal; S2: A mirror-rich raw coal and B silk-rich raw coal are respectively sent to the first friction separation system and the second friction electric separation system to be crushed to less than 150 μm, and then subjected to high-voltage separation after friction charging; S3: After the A vitrinite-rich raw coal enters the first friction separation system, the vitrinite-rich coal particles are enriched in the A negative electrode clean coal, and the inertinite-rich coal particles are enriched in the A positive electrode tail coal. The A negative electrode clean coal is collected, and the A positive electrode tail coal is not collected and directly sent to the second friction separation system for separation; S4: After the B filamentous carbon raw coal enters the second friction separation system, the vitrinite-rich coal particles are enriched in the B negative electrode clean coal, and the inertinite-rich coal particles are enriched in the B positive electrode tail coal. The B positive electrode tail coal is collected, and the B negative electrode clean coal is not collected and directly sent to the first friction separation system for separation; S5: The final collected negative electrode clean coal A is a low-sodium vitrinite-rich product, and the positive electrode tail coal B is a high-sodium inertinite-rich product.

8. The method for removing sodium from high sodium coal based on triboelectric separation of microscopic components according to claim 7, characterized in that: In step 1, the A mirror-rich coal raw material has a particle size of 1-25 mm, and the B silk-rich coal raw material has a particle size of 0-1 mm.

9. The method for removing sodium from high sodium coal based on triboelectric separation of microscopic components according to claim 7, characterized in that: In step 2, the high-sodium coal raw coal is subjected to surface modification treatment before entering the first friction separation system and the second friction electric separation system: when the surface potential difference between the two is greater than 0.45V, no surface modification treatment is added; when the surface potential difference between the two is less than or equal to 0.45V, surface modification treatment is performed.

10. The method for removing sodium from high sodium coal based on triboelectric separation of microscopic components according to claim 9, characterized in that: The surface modifier used in the surface modification treatment is one of light diesel oil, kerosene, ammonia water and ethanol.

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