Coal gangue quality-based separation treatment system based on calorific value classification and use method of coal gangue quality-based separation treatment system

Abstract

The invention relates to the technical field of coal gangue grading separation, in particular to a coal gangue grading separation treatment system based on calorific value classification and a use method of the coal gangue grading separation treatment system. Comprising a front conveying unit used for conveying and drying coal gangue raw materials, a quality separation unit used for crushing, grinding, separating and sorting organic matter and inorganic matter of the coal gangue, a storage unit used for classified storage of finished coal gangue products and a central control unit used for full-process control of the coal gangue. The central control unit calculates suitable system control parameters by receiving test data of coal gangue raw materials and finished products, and preparation of various coal gangue finished products is achieved. According to the coal gangue quality separation treatment system based on calorific value classification, efficient separation of organic matter and inorganic matter of the coal gangue can be achieved, and therefore the high-valued resource utilization rate of the coal gangue is increased, the technical field of coal gangue treatment is expanded, and the treatment progress of stockpiled coal gangue is promoted.

Description

Technical Field

[0001] The present invention relates to the technical field of coal gangue disposal, and in particular to a coal gangue quality separation and disposal system based on calorific value classification and a use method thereof. Background Art

[0002] Gangue is a product of coal seam sedimentation in coal-bearing basins. It is a mixture of organic and inorganic compounds deposited with the coal during coal formation. It typically occurs as a thin layer within, at the top or bottom of, the coal seam. Due to long-term infiltration and diffusion, it also contains a certain amount of carbon, resulting in a dark gray color. Gangue is solid waste discharged during mine excavation, mining, and coal washing.

[0003] At present, gangue crushing technology has been developed for many years at home and abroad. According to the different properties and particle sizes of gangue, the gangue crushing process can be divided into three stages, mainly coarse crushing, medium crushing and fine crushing; with the improvement of crushing equipment, the crushing ratio gradually increases. In order to simplify the process flow, medium crushing and fine crushing will also be merged into one stage to form a two-stage crushing process flow.

[0004] After the gangue is crushed, the coal is enriched in the fine particle size, while the gangue is enriched in the coarse particle size. At the same time, the study found that after multiple crushing and screening and grading by jaw and hammer, the results of each crushing showed that the smaller the particle size, the lower the ash content and the higher the calorific value. In order to study the effective utilization of gangue, crushing, grinding and sorting process equipment were introduced from the ore processing, machine-made sand preparation and other industries, but the existing equipment and processes cannot achieve the separation of the quality of gangue, resulting in a low utilization rate of gangue disposal.

[0005] While gangue can damage the ecological environment, its rich mineral composition, chemical ingredients and special physical properties make it a resource. Currently, many places adopt a mine-power plant regional distribution method to efficiently utilize coal resources. Gangue whose calorific value does not meet the combustion requirements after coal mining and sorting is used as aggregate for underground filling. Gangue with a certain calorific value is mixed with thermal coal and then enters the power plant for combustion, which improves the comprehensive utilization of gangue.

[0006] The selection of coal gangue for underground filling is based on the calorific value of the gangue, resulting in low calorific value (calorific value less than 6270kJ / kg) coal gangue being directly used as filling aggregate, and high calorific value (calorific value above 6270kJ / kg) coal gangue being mixed with thermal coal for combustion. The organic matter (especially C element) and inorganic matter in the coal gangue are not effectively separated, which affects the strength of the coal gangue itself and the extraction and sorting of high calorific value organic matter. The economic value of the coal gangue itself is not fully utilized, which limits the comprehensive utilization efficiency of the coal gangue and causes great waste of coal resources. At the same time, the high calorific value coal gangue does not fully separate the inorganic matter, resulting in a large amount of ash after combustion, which increases the equipment cost of the power plant and increases the risk of secondary pollution. Summary of the Invention

[0007] The present invention provides a coal gangue separation and disposal system based on calorific value classification and its use method, which are used to solve the problem of difficulty in separating different components in coal gangue materials used for underground filling in the prior art and improve the high-value utilization of coal gangue materials.

[0008] In order to solve the above technical problems, the present invention adopts the following technical solutions: A coal gangue separation and disposal system based on calorific value classification includes a front conveying unit, a separation unit, a storage unit and a central control unit respectively connected to the first three units by electrical signals.

[0009] Preferably, the front conveying unit includes a dryer, a buffer bin, a conveying metering device and a corridor connected in sequence, wherein the buffer bin is provided with a weighing sensor, a height sensor and a material moisture detector, which monitor and feed back data to the central control unit in real time, one end of the dryer is connected to the external conveying equipment, and the other end is connected to the buffer bin feed port, the top of the dryer is connected to a hydrocondenser, the end of the buffer bin away from the feed port is connected to the conveying metering device, the conveying metering device is also connected to the crusher of the separation unit, and a first iron remover and a second iron remover are respectively installed at the dryer inlet and the buffer bin outlet to adsorb ferromagnetic impurities in the coal gangue.

[0010] Preferably, the buffer bin has a weighing and height sensor and a material moisture detector. By measuring the gangue pile in the buffer bin, the feeding speed of the gangue entering the buffer bin is adjusted to ensure the feeding speed of the gangue entering the subsequent quality separation unit and maintain the stability of the system's disposal level. The material moisture detector is built into the discharge port of the buffer bin and feeds back to the central control unit to feed back the operation of the material layer stabilization device.

[0011] Preferably, the quality separation unit includes a vertical mill and a dynamic and static classifier, which sprays dry ice as a hydrocoagulant and grinding aid through a material layer stabilization device arranged inside the vertical mill, and the dynamic and static classifier uses wind power to effectively separate the various components of the coal gangue into storage units for separate storage; the quality separation unit also includes a crusher, a static classifier, a grading screen arranged in sequence at the front end of the vertical mill, and a high-frequency classifier and a dynamic and static classifier arranged at the rear end of the vertical mill, wherein the static classifier is connected to the powder collector through a conveying device, and the high-frequency classifier is connected to the vertical mill through another set of conveying devices.

[0012] Preferably, the vertical mill includes a drop pipe, a crushing roller, a grinding roller, a retaining ring, a grinding disc and a material layer stabilizing device; gangue particles with r≤30mm fall to the center of the grinding disc through the drop pipe on the top plate of the vertical mill, and the grinding disc moves, causing the gangue particles to undergo centrifugal motion. When the crushing interval is reached, the crushing roller crushes the gangue particles. Due to the selective crushing characteristics of the material layer, the lower hardness part of the gangue is crushed and separated, and then the particles continue to move toward the edge of the grinding disc under centrifugal motion, and the internal retaining ring classes the material layer. Particles with r≥5mm will continue to be crushed by the crushing roller in the crushing area, and particles with r<5mm will pass through the internal retaining ring and reach the grinding area with centrifugal motion, and be ground by the grinding roller. Due to the selective crushing characteristics of the material layer in this area, the particles of different hardness inside the particles are further separated to form a particle material layer, which reaches the edge of the grinding disc as the material layer moves and falls into the collecting port of the vertical mill, and is then sent to the high-frequency classifier by conveying equipment.

[0013] Preferably, the material layer stabilizing device includes a support structure for leveling the material layer, one side of the support structure is fixedly connected to the edge of the grinding disc, and the other side of the support structure is fixed with an adjusting frame through an electric cylinder, the bottom of the adjusting frame is connected to a material stabilizing roller, and the top of the material stabilizing roller is provided with a plurality of dry ice nozzles that can electrically adjust the injection flow and angle, and the electric cylinder can drive the adjusting frame to change the height of the material stabilizing roller and the dry ice nozzle, and the dry ice nozzle is connected to a dry ice storage device through a dry ice connecting pipe, wherein the spray direction of the dry ice nozzle of the material layer stabilizing device is aligned with the material layer movement path of the grinding disc.

[0014] Preferably, the central control unit collects, analyzes, judges and regulates the data of other working units, so as to ensure the stability of the system's separation and disposal functions, drive the separation by the calorific value of the gangue and form a closed-loop control; the gangue is sent to the separation unit through the front conveying unit, and the gangue first enters the crusher for the first crushing. The crusher crushes the material to ≤30mm, and uses the conveying equipment to enter the static classifier. The static classifier collects the particles with a particle size of r≤0.075mm and enters the powder collector. The particles with a particle size of r>0.075mm are introduced into the grading screen. A layer of sieve with an aperture of 30mm is set in the grading screen, and the screening particle size r>30 mm coal gangue blocks return to the crusher for further crushing, and the coal gangue particles with a particle size of 0.075mm<r≤30mm enter the vertical mill for fine grinding. The vertical mill realizes hardness layer separation through the material layer stabilization device and the grinding roller, and then performs secondary screening through a high-frequency classifier with a 5mm aperture, so that the coal gangue particles with a particle size of r≥5mm return to the vertical mill for further crushing and grinding, and the coal gangue particles with a particle size of r<5mm enter the dynamic and static classifier, and the dynamic and static classifier is wind-sorted according to the particle size: r≤0.08mm to the gangue powder storage, 0.08mm<r≤0.15mm to the gangue particle storage, and 0.15<r<5mm to the aggregate storage.

[0015] Preferably, the central control unit dynamically controls the dry ice delivery amount of the dry ice storage device based on the data of the material moisture detector at the outlet of the buffer bin of the front conveying unit, combined with the material layer vibration data, so as to adjust the humidity and stability of the material layer in the vertical mill; the height of the electric cylinder and the injection flow and angle of the dry ice nozzle are adjusted in real time by the central control unit according to the thickness of the material layer, and the pressure parameter of the dry ice storage device is linked to the speed of the grinding disc. When the speed is increased to the threshold, the dry ice injection amount increases by 10% to 15% year-on-year.

[0016] Preferably, the storage unit includes a gangue powder storage, a gangue particle storage and an aggregate storage; the grading logic of the quality separation unit is: the static classifier separates r≤0.075mm particles to the powder collector, and r>0.075mm particles to the grading screen; the grading screen is provided with a 30mm screen, 0.075mm<r≤30mm particles enter the vertical mill, and r>30mm stones return to the stone crusher; the high-frequency classifier is provided with a 5mm screen, r<5mm particles enter the dynamic and static classifier, and r≥5mm particles return to the vertical mill; the dynamic and static classifier is wind-forced sorting according to particle size: r≤0.08mm to the gangue powder storage, 0.08mm<r≤0.15mm to the gangue particle storage, and 0.15<r<5mm to the aggregate storage; wherein, this specification The r appearing in the figure is the particle size of the coal gangue. According to the above logic, the dynamic and static classifiers of the separation unit separate the particles of different sizes through wind screening and enter the corresponding warehouse of the storage unit; the storage unit also includes a transportation device, and the gangue powder warehouse and the gangue particle warehouse are both provided with an online calorific value detection device. The online calorific value detection device and the transportation device are both electrically connected to the central control unit. The transportation device is connected to a high calorific value material warehouse and a low calorific value material warehouse. The online calorific value detection device can detect the calorific value of the coal gangue in the gangue powder warehouse and the gangue particle warehouse, and transmit the value to the central control unit. The central control unit decides according to the preset value whether to transport the coal gangue in the gangue powder warehouse and the gangue particle warehouse to the high calorific value material warehouse or the low calorific value material warehouse through the transportation equipment.

[0017] A method for using a coal gangue separation and disposal system based on calorific value classification includes the following steps: Parameter calibration stage: sampling and calorific value analysis of coal gangue, determination of initial calorific value, moisture content and hardness distribution, and grindability testing and parameter setting; Pre-treatment stage: The central control unit determines the operating parameters of each system device based on the calorific value. The equipment starts up, the system operates, and the gangue raw material enters the separation system. After drying and iron removal in the pre-conveyor unit, it enters the separation unit. The gangue is transported through the corridor to the first iron remover to remove iron impurities, enters the dryer, and then enters the buffer silo. The buffer silo uses feedback from the height sensor and moisture detector to adjust the drying temperature and residence time of the dryer to reduce the moisture content of the material. Separation stage: After the gangue is crushed, ground and sorted in the separation unit, it enters the gangue powder storage, gangue particle storage and aggregate storage of the storage unit respectively; the crusher crushes the material to ≤30mm and uses the conveying equipment to enter the static classifier. The static classifier collects the particles with a particle size of r≤0.075mm and enters the powder collector. The particles with a particle size of r>0.075mm are introduced into the grading screen. A layer of 30mm aperture screen is set in the grading screen to screen the gangue pieces with a particle size of r>30mm and return to the crusher for further processing. After continuous crushing, the gangue particles with a particle size of 0.075mm<r≤30mm enter the vertical mill for fine grinding. The vertical mill realizes hardness layer separation through the material layer stabilization device and the grinding roller, and then performs secondary screening through a high-frequency classifier with a 5mm aperture, so that the gangue particles with a particle size of r≥5mm return to the vertical mill for continued crushing and grinding, and the gangue particles with a particle size of r<5mm enter the dynamic and static classifier, which performs precise dynamic air separation according to the threshold values ​​of 0.08mm and 0.15mm.

[0018] Classification and storage stage: After each component material is transported to the gangue powder warehouse, gangue pellet warehouse and aggregate warehouse of the corresponding storage unit, the central control unit monitors the material level of each warehouse in real time and records the storage quantity through the intelligent metering system; the calorific value of the materials in the gangue powder warehouse and gangue pellet warehouse is measured by online calorific value detection equipment, and the result is transmitted to the central control unit. The central control unit controls the finished product conveying device in the storage unit to transport the materials in the gangue powder warehouse and gangue pellet warehouse to the low calorific value material warehouse or the high calorific value material warehouse according to the material preparation plan set by the system.

[0019] Preferably, in the pre-pretreatment stage, the residence time is dynamically adjusted according to the initial moisture content of the gangue, the drying temperature is 120° C. to 180° C., and the generated hot water vapor is recovered through a condenser.

[0020] It can be seen from the above technical solution that the present invention has the following beneficial effects: coal gangue products are classified according to different calorific values, coal gangue is separated by quality, and the calorific value of gangue powder is improved; and equipment parameters are controlled based on the dual variables of calorific value and particle size to achieve product control and improve product added value; using dry ice as a hydrocoagulant / grinding aid can better separate the gangue and stabilize the material layer. Through the above innovations, the effective separation of the various components of coal gangue can be achieved, the added value of coal gangue products can be improved, the scale of coal gangue disposal and the downstream product market can be expanded, and environmental pollution can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a block diagram of the system unit composition of the present invention; Figure 2 This is a diagram showing the modular composition of the conveying unit, mass separation unit, storage unit, and central control unit of the present invention; Figure 3 A schematic structural diagram of a vertical mill according to an embodiment of the present invention; Figure 4 This is a functional schematic diagram of the gangue crushing zone of a vertical mill according to an embodiment of the present invention; Figure 5 This is a functional schematic diagram of the gangue grinding area of ​​a vertical mill according to an embodiment of the present invention; Figure 6 Schematic diagram of the movement of gangue on the grinding plate of a vertical mill according to an embodiment of the present invention; Figure 7 This is a schematic structural diagram of a device for stabilizing a material layer in a vertical mill according to an embodiment of the present invention; Figure 8 This is a schematic diagram of the use of a device for stabilizing a material layer in a vertical mill according to an embodiment of the present invention; Figure 9 This is a carbon element distribution diagram of the coal gangue raw material before treatment according to an embodiment of the present invention; Figure 10 This is a carbon element distribution diagram of the treated coal gangue liver powder according to an embodiment of the present invention.

[0022] Figure: 1. Pre-conveyor unit; 101. Dryer; 102-01. First iron remover; 102-02. Second iron remover; 103. Buffer bin; 104. Conveying and metering device; 105. Hydrocondenser; 2. Separation unit; 201. Crusher; 202. Static classifier; 203. Classifying screen; 204. Vertical mill; 205. High-frequency classifier; 206. Dynamic and static classifier; 207. Powder collector; 208. Dropping pipe; 209 , grinding roller; 210, grinding disc; 211, material blocking ring; 212, crushing roller; 213, material layer stabilizing device; 214, supporting structure; 215, material stabilizing roller; 216, dry ice nozzle; 217, dry ice connecting pipe; 218, dry ice storage device; 3, storage unit; 301, gangue powder warehouse; 302, gangue particle warehouse; 303, aggregate warehouse; 304, high calorific value material warehouse; 305, low calorific value material warehouse; 306, transportation equipment; 4, central control unit. DETAILED DESCRIPTION

[0023] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is further described below in conjunction with specific embodiments.

[0024] Example: Figures 1-10 As shown, the coal gangue separation and disposal system based on calorific value classification described in the present invention includes a front conveying unit 1, a separation unit 2, a storage unit 3 and a central control unit 4 electrically connected to the first three units respectively; wherein, the central control unit 4 collects, analyzes, judges and regulates the data of each working unit to ensure the stability of the separation and disposal function, drives the separation by the calorific value of the coal gangue and forms a closed-loop control.

[0025] Specifically, the front conveying unit 1 includes a dryer 101, a buffer bin 103, a conveying metering device 104 and a corridor connected in sequence, wherein the buffer bin 103 is provided with a weighing sensor, a height sensor and a material moisture detector, which monitors in real time and feeds back data to the central control unit 4. One end of the dryer 101 is connected to the external conveying equipment, and the other end is connected to the inlet of the buffer bin 103. A hydrocondenser 105 is connected to the top of the dryer 101, and the end of the buffer bin 103 away from the inlet is connected to the conveying metering device 104. The conveying metering device 104 is also connected to the crusher 201 of the separation unit 2, and a first iron remover 102-01 and a second iron remover 102-02 are respectively installed at the inlet of the dryer 101 and the outlet of the buffer bin 103 to adsorb ferromagnetic impurities in the coal gangue.

[0026] In this embodiment, the mass separation unit 2 includes a vertical mill 204 and a dynamic and static classifier 206. The material layer stabilization device 213 provided inside the vertical mill 204 sprays dry ice as a hydrogel and a grinding aid, and the spraying direction is in the same direction as the rotation direction of the grinding disc 210 of the vertical mill 204 to stabilize the material layer (with water content and vibration as the main parameters). Dry ice adding equipment and gas recovery equipment can also be added to the vertical mill 204 to achieve gas recovery. The dynamic and static classifier 206 utilizes The various components of the coal gangue are effectively separated by wind power and stored in the storage unit 3 respectively; the quality separation unit 2 also includes a crusher 201, a static classifier 202, a grading screen 203 arranged in sequence at the front end of the vertical mill 204, and a high-frequency classifier 205 and a dynamic and static classifier 206 arranged at the rear end of the vertical mill 204, wherein the static classifier 202 is connected to the powder collector 207 through a conveying device, and the high-frequency classifier 205 is connected to the vertical mill 204 through another set of conveying devices.

[0027] Specifically, the vertical mill 204, such as Figure 3-Figure 6As shown, it includes a drop pipe 208, a grinding roller 209, a grinding disc 210, a blocking ring 211, a crushing roller 212 and a material layer stabilizing device 213, r≤30mm (r here and in the following text is the particle size of coal gangue). The coal gangue particles fall to the center of the grinding disc 210 through the drop pipe 208 on the top plate of the vertical mill 204. The grinding disc 210 rotates and the coal gangue particles undergo centrifugal motion. When they reach the crushing zone (that is, the crushing roller 212 can crush the coal gangue particles), the coal gangue particles are crushed. The crushing roller 212 crushes the gangue particles. Due to the selective crushing characteristics of the material layer, that is, during the crushing process, the material undergoes non-uniform crushing under the action of mechanical external forces (such as extrusion, shearing, and impact) due to the hardness, brittleness or structural differences between the particles. The organic matter in the gangue has a lower hardness (1-2) and is crushed and separated, while the inorganic matter has a higher hardness (4-7), resulting in interface microcracks. The gangue particles are subjected to centrifugal force to form a material layer. The low-hardness coal particles are preferentially crushed into fine powder, while the high-hardness gangue particles retain a larger particle size. A retaining ring 211 is provided between the crushing zone and the grinding zone, wherein the retaining ring 211 is provided with a 5mm screen. The crushed particles with a particle size r≤5mm can reach the grinding zone (that is, the position interval where the grinding roller 209 can grind the gangue particles) through the gap of the retaining ring 211 and are ground by the grinding roller 209. At the same time, with the assistance of low-temperature embrittlement of dry ice, the different hardness inorganic and organic substances inside the particles are The carbon is further separated, and the organic matter is separated from the gangue matrix. As the material layer moves, it reaches the edge of the grinding disc 210 and falls into the aggregate port of the vertical mill 204. It is then sent to the high-frequency classifier 205 by conveying equipment to achieve physical separation; through selective crushing, it is divided into gangue powder (r≤0.08mm enriched high calorific value coal), gangue particles (0.08mm<r≤0.15mm), and aggregates (0.15<r<5mm mainly gangue), providing a basis for subsequent calorific value classification.

[0028] Specifically, the material layer stabilizing device 213 is as follows: Figure 7 As shown, it includes a support structure 214 for leveling the material layer, one side of the support structure 214 is fixedly connected to the edge of the grinding disc 210, and the other side of the support structure 214 is fixed with an adjustment frame through an electric cylinder, and the bottom of the adjustment frame is connected to a material stabilizing roller 215. According to the required material layer thickness, the adjustment frame can adjust the height of the material stabilizing roller 215 from the grinding disc 210 through the electric cylinder, and a plurality of dry ice nozzles 216 are fixed on the top of the material stabilizing roller 215. The dry ice nozzles 216 are connected to a dry ice storage device 218 through a dry ice connecting pipe 217, wherein the spray direction of the dry ice nozzle 216 of the material layer stabilizing device 213 is aligned with the material layer movement path of the grinding disc 210.

[0029] In this embodiment, if Figure 7-Figure 8The core mechanism of the material layer stabilization device 213 is to use the heat absorption of dry ice volatilization to achieve temperature control and brittleness enhancement, optimize powder fluidity and control the thickness and density of the material layer; among them, the low-temperature embrittlement effect (after the dry ice is sprayed onto the coal gangue material layer at -78.5℃, it absorbs heat by sublimation and absorbs about 573kJ / kg of heat, which quickly reduces the material temperature, causing the organic matter in the coal gangue, such as residual coal, and the inorganic matter, such as clay minerals, to produce microcracks due to the difference in thermal expansion coefficient, and the hardness is reduced by 20%~40%), selective crushing promotion (organic matter is more brittle at low temperatures, and is crushed first during grinding, achieving efficient dissociation of organic matter and gangue matrix), dry ice particles The dry ice particles have a lubricating effect (the dry ice particles with a diameter of 0.5~2mm act as "micro bearings" in the material layer, reducing the friction coefficient between particles by 30%~50%, preventing the material from adhering to the grinding disc), static elimination (the CO2 gas generated by the sublimation of dry ice can neutralize the static electricity on the powder surface and avoid uneven material layer caused by agglomeration of fine powder), and a dynamic compensation mechanism (the material layer status is monitored in real time through weighing sensors and vibration sensors; that is, the central control unit 4 needs to adjust the dry ice spraying amount according to the porosity feedback of the material layer. When the porosity is greater than 40%, the dry ice spraying amount is increased to fill the gaps; when the porosity is less than 25%, the dry ice is reduced to avoid over-compaction).

[0030] Among them, the central control unit 4 dynamically controls the dry ice delivery amount of the dry ice storage device 218 based on the data of the material moisture detector at the discharge port of the buffer bin 103 of the front conveying unit 1, combined with the material layer vibration data, to adjust the humidity and stability of the material layer in the vertical mill 204; the height of the electric cylinder, the injection flow rate and angle of the dry ice nozzle 216 are adjusted in real time by the central control unit 4 according to the thickness of the material layer, and the pressure parameters of the dry ice storage device 218 are linked to the rotation speed of the grinding disc 210. When the rotation speed increases to a threshold, the dry ice injection amount increases by 10% to 15% year-on-year.

[0031] Specifically, the storage unit 3 includes a gangue powder storage 301, a gangue particle storage 302 and an aggregate storage 303; wherein, the grading logic of the quality separation unit 2 is as follows: the static classifier 202 separates particles with r≤0.075mm to the powder collector 207, and particles with r>0.075mm to the grading screen 203; the grading screen 203 is provided with a 30mm screen, and stones with r>30mm return to the crusher 201, and particles with r≤30mm enter the vertical mill 204; the high-frequency classifier 205 is provided with a 5m m sieve, particles with r≥5mm return to the vertical mill 204, and particles with r<5mm enter the dynamic and static classifier 206; the dynamic and static classifier 206 sorts according to particle size: r≤0.08mm to the gangue powder bin 301, 0.08<r≤0.15mm to the gangue particle bin 302, 0.15<r≤5mm to the aggregate bin 303; according to the above logic, the dynamic and static classifier 206 of the quality separation unit 2 screens particles of different particle sizes through wind power and enters the corresponding bin of the storage unit 3.

[0032] Specifically, the storage unit 3 also includes a transportation device 306. The gangue powder warehouse 301 and the gangue particle warehouse 302 are both provided with an online calorific value detection device. The online calorific value detection device and the transportation device 306 are both electrically connected to the central control unit 4. The transportation device 306 is connected to the high calorific value material warehouse 304 and the low calorific value material warehouse 305. The online calorific value detection device can detect the calorific value of the coal gangue in the gangue powder warehouse 301 and the gangue particle warehouse 302, and transmit the value to the central control unit 4. The central control unit 4 decides whether to transport the coal gangue in the gangue powder warehouse 301 and the gangue particle warehouse 302 into the high calorific value material warehouse 304 or the low calorific value material warehouse 305 through the transportation device 306 according to the preset value.

[0033] A method for using a gangue separation and disposal system, the steps of which are as follows: S1. Parameter calibration stage: Sampling and calorific value analysis of coal gangue, determination of initial calorific value, moisture content and hardness distribution, and grindability test and parameter setting. It should be noted that different batches of coal gangue need to be re-sampled and calorific value analyzed before entering the system; specifically including: S1.1: Randomly sample 2 kg of the gangue entering the system, crush it with a jaw crusher, sieve it with standard sieves of different particle sizes, and collect the gangue particles in different particle size ranges, number them x1, x2, x3...xn, measure their calorific values ​​and record Qx1, Qx2, Qx3...Qxn respectively. Let Q0(x) = ; S1.2: Determine the grindability of coal gangue according to the GB / T cement grindability method and record G(x). Let the standard operating parameter array of the coal gangue separation system be Ps= , then the system operation parameter array can be obtained according to the relevant initial parameters:

[0034] Where μ(x) is the correction function for the calorific value of gangue in different particle size ranges.

[0035] in is the average particle size in a certain particle size range, is the optimal particle size expected by the system, is the benchmark calorific value of coal gangue. Since μ(x) is based on the data obtained from the production system, it also needs to be adjusted in time according to the following three stages.

[0036] S2, pre-processing stage: The central control unit 4 determines the operating parameters of each device in the system according to the calorific value. The equipment is started, the system is in operation, and the gangue raw materials enter the separation system. After the moisture drying and iron removal operations of the pre-transporting unit 1, they enter the separation unit 2. Specifically, it includes: S2.1: The central control unit 4 determines the operating parameters of each device in the system based on the calorific value, starts the device, and the system operates; S2.2: The gangue is transported via a corridor to the first iron remover 102-01 to remove iron impurities. It then enters the dryer 101 and then the buffer bin 103. The buffer bin 103 receives feedback from a height sensor and a moisture detector. The central control unit 4 regulates the drying temperature and residence time in the dryer 101 to reduce the moisture content of the material. The residence time is dynamically adjusted based on the initial moisture content of the gangue. The drying temperature is 120°C to 180°C. The generated hot water vapor is recovered by the condenser 105. S2.3: The dried gangue material enters the buffer bin 103, and after the gangue temperature cools to 60°C, it passes through the second iron remover 102-02 and is sent out of the front conveying unit 1 by the conveying and metering device 104.

[0037] S3, separation stage: After the gangue is crushed, ground and sorted by the separation unit 2, it enters the gangue powder storage 301, gangue particle storage 302 and aggregate storage 303 of the storage unit 3 respectively; specifically, it includes: S3.1: Gangue from pre-conveyor unit 1 enters crusher 201 for initial crushing. Crusher 201 crushes the material to ≤30 mm. The material is then conveyed to static classifier 202. Static classifier 202 collects particles with a size of r ≤ 0.075 mm and sends them to powder collector 207. Particles with a size of r > 0.075 mm are then fed to grading screen 203. Grading screen 203 is equipped with a 30 mm mesh. The sieved gangue particles with a size of r > 30 mm are then returned to crusher 201 for further crushing. S3.2: Gangue particles with a particle size of 0.075 mm < r ≤ 30 mm enter the vertical mill 204 for fine grinding. The vertical mill 204 uses the material layer stabilizer 213 and the grinding roller 209 to separate the hardness layers. Subsequently, the high-frequency classifier 205 with a 5 mm aperture performs secondary screening. The gangue particles with a particle size of r ≥ 5 mm return to the vertical mill 204 for further crushing and grinding. S3.3: Gangue particles with a particle size of r < 5 mm enter the dynamic and static classifier 206, which is then wind-sorted according to the particle size. Particles with r ≤ 0.08 mm are sent to the gangue powder bin 301, those with 0.08 mm < r ≤ 0.15 mm are sent to the gangue particle bin 302, and those with 0.15 < r < 5 mm are sent to the aggregate bin 303.

[0038] S4, classification and storage stage: After each component material is transported to the gangue powder warehouse 301, gangue particle warehouse 302 and aggregate warehouse 303 of the corresponding storage unit 3, the central control unit 4 monitors the material level of each warehouse in real time and records the storage quantity through the intelligent metering system; the calorific value of the materials in the gangue powder warehouse 301 and gangue particle warehouse 302 is measured by the online calorific value detection equipment, and the result is transmitted to the central control unit 4. The central control unit 4 controls the finished product conveying device in the storage unit 3 to transport the materials in the gangue powder warehouse 301 and gangue particle warehouse 302 to the low calorific value material warehouse 305 or the high calorific value material warehouse 304 according to the material preparation plan set by the system; specifically, the following steps are performed: S4.1: Use online calorific value detection equipment (the specific model can be selected according to actual needs and budget in Table 1, and other equipment that can replace any of the equipment in Table 1) to test the calorific value of the materials in the gangue powder storage 301 and the gangue particle storage 302, and record the calorific value Q respectively. i1 , Q i2 , refer to Table 2, according to Q i1 , Q i2 Is the value greater than 6270kJ / kg? It is determined whether the materials in the gangue powder warehouse 301 and the gangue particle warehouse 302 need to be transported by the transportation equipment 306 to the high calorific value material warehouse 304 or the low calorific value material warehouse 305. For example, if the calorific value test result in the gangue powder warehouse 301 is Q i1 ≥6270kJ / kg, the materials in the gangue storehouse 301 need to be transported to the high calorific value material storehouse 304 through the transportation equipment 306. i1 <6270kJ / kg, it is transported to the low calorific value material warehouse 305; Table 1 Mainstream online calorific value detection equipment types and indicators

[0039] Note: All the above-mentioned types of online calorific value detection equipment can meet the scenario of judging whether the calorific value of coal gangue is above or below 6270kJ / kg. Among them, the LIBS equipment has a faster response time and is more in line with the usage scenario of the present invention, so it can be preferred.

[0040] Table 2 Calorific value judgment of gangue powder storage and gangue particle storage

[0041] S4.2: Determine the mass proportion of the materials in the gangue bin 301, gangue granule bin 302 and aggregate bin 303 through the weighing devices of each finished product bin, and record the proportion as k i1 、k i2 、k i3 ; S4.3: Calculation According to the control content of Table 3, determine which material is suitable for this batch of gangue to produce and output, understand its material properties (high and low calorific value materials, aggregates) and their respective proportions. For example, in the table below, number D2, its Q i >0, K=0, which means that this batch of coal gangue can be used to prepare both high calorific value materials (gangue powder and gangue particles) and aggregates, and the proportions of the two are the same.

[0042] Table 3 Control parameter group of coal gangue separation and disposal system

[0043] In this embodiment, in the "S1, parameter calibration stage" of a method for using a gangue separation and disposal system, each time a batch of gangue is replaced, it is necessary to re-prepare gangue samples and perform parameter calibration experiments, and calibrate and correct parameter formulas to optimize the operating parameters of the gangue separation system. The specific test experimental process is as follows: Step 1: Sample grouping and pretreatment. The same batch of coal gangue raw materials was selected and initially crushed by a jaw crusher (model PE-250×400). The samples were then sieved using a standard sieve (GB / T 6003.1-2022 "Technical requirements and inspection of test sieves - Part 1: Wire mesh test sieves") into five particle size ranges: 0-1mm, 1-3mm, 3-5mm, 5-8mm, and 8-10mm. The average particle size of each group was recorded. Each particle size sample was further divided into three subgroups by adding high calorific value coal gangue. ≥6.27MJ / kg) or low calorific value coal gangue ≤6.27MJ / kg), adjust the subgroup calorific value to three levels: low (1.5~2.09MJ / kg), medium (2.09~6.27MJ / kg), and high (6.27~12.25MJ / kg) to ensure that the calorific value gradient covers the actual operating range.

[0044] Step 2: Determination of key parameters. Calorific value determination: According to GB / T213-2008 "Determination of calorific value of coal", use oxygen bomb calorimeter (model ZDHW-8) to determine the calorific value of each subgroup , accurate to 0.1MJ / kg; Grindability determination: According to GB / T26567-2011 "Test method for grindability of cement raw materials", a Φ305×305mm standard ball mill is used to determine the Bond work index G (x), unit kWh / t; System operation parameter collection: Each sub-group of coal gangue is input into the separation system, and the actual operation parameters (including the speed of the main motor of the vertical mill 204, the speed of the main motor of the powder concentrator, feeding speed, etc.) are recorded.

[0045] Step 3: Data collection and processing. Each experiment was repeated 3 times, resulting in a total of 45 sets of data (5 sets of particle size × 3 sets of calorific value × 3 repetitions). After removing outliers, the average was taken and the final reference value was set: =0.5mm (median particle size), =15MJ / kg (industry benchmark value).

[0046] Step 4: Parameter fitting and verification. Based on the formula, the theoretical value is deduced. Using the nonlinear least squares method, multiple regression is performed and k=1.25, α=0.68, β=0.15 are obtained. The fitting determination coefficient R 2 =0.92.

[0047] Verification: 20% of the data (9 groups) were randomly selected for cross-validation, and the prediction error was ≤8%, meeting the engineering accuracy requirements.

[0048] Implementation effect: After parameter calibration, the system operating parameters The calculation error of the original model was reduced from 22% to 9%, significantly improving the system's mass separation efficiency and energy consumption control accuracy; In this embodiment, product element spectrum detection was performed on the gangue raw materials, the low calorific value material library 305, and the high calorific value material library 304. The Thermo Fisher QuattroS equipped with a field emission electron gun (with a spatial resolution of nanometers) suitable for micro-area element analysis was used in conjunction with the EDAX ELECTPLUS spectrometer to achieve rapid surface scanning and element distribution imaging, as shown below. Figure 9 and Figure 10 The carbon element distribution diagram shown is used to determine the calorific value of the sample through testing, and the following two Tables 4 and 5 are obtained for reference.

[0049] Table 4 Element weight and calorific value of coal gangue raw materials

[0050] Table 5 Material element weight and calorific value of coal gangue powder storage

[0051] The above-described embodiments are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should fall within the scope of protection determined by the claims of the present invention.

Claims

1. A coal gangue separation and disposal system based on calorific value classification, characterized by: It comprises a front conveying unit (1), a mass separation unit (2), a storage unit (3), and a central control unit (4) connected to the first three units by electrical signals respectively; The mass separation unit (2) includes a vertical mill (204) and a dynamic and static classifier (206). The material layer stabilizing device (213) provided inside the vertical mill (204) sprays dry ice in the same direction as the rotation direction of the grinding disc (210) of the vertical mill (204) to stabilize the material layer. The dynamic and static classifier (206) uses wind power to separate the various components of the coal gangue into the storage unit (3) and store them separately. The central control unit (4) collects, analyzes, judges and regulates the data of each working unit to ensure the stability of the separation and disposal function, drives the separation through the calorific value of the coal gangue and forms a closed-loop control.

2. The coal gangue separation and disposal system based on calorific value classification according to claim 1 is characterized by: The material layer stabilizing device (213) includes a support structure (214) for leveling the material layer, one side of the support structure (214) is fixedly connected to the edge of the grinding disc (210), and the other side of the support structure (214) is fixed with an adjustment frame via an electric cylinder, the bottom of the adjustment frame is connected to a material stabilizing roller (215), and the top of the material stabilizing roller (215) is fixed with a plurality of dry ice nozzles (216) capable of electrically adjusting the injection flow rate and angle, and the dry ice nozzles (216) are connected to a dry ice storage device (218) via a dry ice connecting pipe (217), wherein the injection direction of the dry ice nozzles (216) of the material layer stabilizing device (213) is in the same direction as the material layer movement path of the grinding disc (210).

3. The coal gangue separation and disposal system based on calorific value classification according to claim 2 is characterized by: The mass separation unit (2) further comprises a crusher (201), a static classifier (202), a grading screen (203) and a high-frequency classifier (205) arranged in sequence at the front end of the vertical mill (204) and the dynamic and static classifier (206), wherein the static classifier (202) is connected to the powder collector (207) via a conveying device, and the high-frequency classifier (205) is connected to the vertical mill (204) via another set of conveying devices.

4. The coal gangue separation and disposal system based on calorific value classification according to claim 3 is characterized by: The central control unit (4) dynamically controls the dry ice delivery amount of the dry ice storage device (218) based on data from a material moisture detector at the outlet of the buffer bin (103) of the front conveying unit (1) and combined with material layer vibration data, so as to adjust the humidity and stability of the material layer in the vertical mill (204).

5. The coal gangue separation and disposal system based on calorific value classification according to claim 4 is characterized by: The storage unit (3) includes a gangue powder storage (301), a gangue particle storage (302) and an aggregate storage (303); the hierarchical logic of the quality separation unit (2) is: The static classifier (202) separates particles with r≤0.075 mm to a powder collector (207), and particles with r>0.075 mm to a grading screen (203); The grading screen (203) is provided with a 30 mm screen, and particles with a diameter of 0.075 mm < r ≤ 30 mm enter the vertical mill (204), while stones with a diameter of r > 30 mm return to the crusher (201); The high-frequency classifier (205) is equipped with a 5 mm screen, and particles with r < 5 mm enter the dynamic and static classifier (206), while particles with r ≥ 5 mm return to the vertical mill (204); The dynamic and static classifier (206) is used to separate particles by wind power according to particle size: r≤0.08mm is sent to the gangue dust storage (301), 0.08mm<r≤0.15mm is sent to the gangue particle storage (302), and 0.15<r<5mm is sent to the aggregate storage (303); Wherein, r is the particle size of the coal gangue. According to the above logic, the separation unit (2) screens particles of different particle sizes and enters the corresponding reservoir of the storage unit (3).

6. The coal gangue separation and disposal system based on calorific value classification according to claim 5 is characterized by: The storage unit (3) further includes a transport device (306), the gangue powder storage (301) and the gangue particle storage (302) are both provided with an online calorific value detection device, the online calorific value detection device and the transport device (306) are both electrically connected to a central control unit (4), and the transport device (306) is connected to a high calorific value material storage (304) and a low calorific value material storage (305).

7. The coal gangue separation and disposal system based on calorific value classification according to claim 4 is characterized by: The height of the electric cylinder and the spray flow rate and angle of the dry ice nozzle (216) are adjusted in real time by the central control unit (4) according to the thickness of the material layer, and the spray pressure parameter of the dry ice storage device (218) of the material layer stabilization device (213) is linked to the rotation speed of the grinding disk (210) of the vertical mill (204).

8. The coal gangue separation and disposal system based on calorific value classification according to claim 3 is characterized by: The front conveying unit (1) includes a dryer (101), a buffer bin (103), a conveying metering device (104) and a corridor connected in sequence, wherein the buffer bin (103) is provided with a weighing sensor, a height sensor and a material moisture detector, which monitors in real time and feeds back data to a central control unit (4). One end of the dryer (101) is connected to an external conveying device, and the other end is connected to an inlet of the buffer bin (103). A hydrocondenser (105) is connected to the top of the dryer (101). The end of the buffer bin (103) away from the inlet is connected to the conveying metering device (104). The conveying metering device (104) is also connected to a crusher (201) of the mass separation unit (2). A first iron remover (102-01) and a second iron remover (102-02) are respectively installed at the inlet of the dryer (101) and the outlet of the buffer bin (103) to absorb ferromagnetic impurities in the coal gangue.

9. The method for using the coal gangue separation and disposal system based on calorific value classification according to any one of claims 1 to 8, characterized in that: The following steps are included: Parameter calibration stage: sampling and calorific value analysis of coal gangue, determination of initial calorific value, moisture content and hardness distribution, and grindability testing and parameter setting; Pre-processing stage: The central control unit (4) determines the operating parameters of each device in the system according to the calorific value, starts the equipment, and the system operates. The gangue raw materials enter the separation system and pass through the moisture drying and iron removal operations of the pre-transport unit (1) before entering the separation unit (2). Separation stage: after the gangue is crushed, ground and sorted in the separation unit (2), it enters the gangue powder storage (301), gangue particle storage (302) and aggregate storage (303) of the storage unit (3); Classification storage stage: After each component material is transported to the gangue powder warehouse (301), gangue particle warehouse (302) and aggregate warehouse (303) of the corresponding storage unit (3), the central control unit (4) monitors the material level of each warehouse in real time and records the storage quantity through the intelligent metering system; the calorific value of the materials in the gangue powder warehouse (301) and gangue particle warehouse (302) is measured by the online calorific value detection equipment, and the result is transmitted to the central control unit (4). The central control unit (4) controls the finished product transportation equipment (306) in the storage unit (3) to transport the materials in the gangue powder warehouse (301) and gangue particle warehouse (302) to the low calorific value material warehouse (305) or the high calorific value material warehouse (304) according to the material preparation plan set by the system.

10. The method for using the coal gangue separation and disposal system based on calorific value classification according to claim 9 is characterized in that: In the pre-treatment stage, the residence time is dynamically adjusted according to the initial moisture content of the gangue, the drying temperature is 120°C to 180°C, and the generated hot water vapor is recovered through the condenser (105).

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