Coal gangue separation and disposal system based on calorific value classification and method of using same

Abstract

The present application relates to coal gangue quality separation technical field, specifically a kind of coal gangue quality separation disposal system based on calorific value classification and its use method, including the front conveying unit for conveying and drying coal gangue raw materials, the quality separation unit for coal gangue organic matter and inorganic matter crushing, grinding, separation and sorting, the storage unit for coal gangue finished product classification storage and the central control unit of coal gangue whole-process control, central control unit is calculated by receiving coal gangue raw materials, the test data of finished product suitable system control parameter, realize the preparation of multiple coal gangue finished product;The present application can realize the efficient separation of coal gangue organic matter and inorganic matter by the above-mentioned coal gangue quality separation disposal system based on calorific value classification, to improve coal gangue high-value resource utilization, expand coal gangue disposal technical field, promote the disposal progress of stockpiled coal gangue.

Description

TECHNICAL FIELD

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

[0002] Coal gangue is a product of coal accumulation in a coal basin, and is a rock mixed with organic and inorganic compounds deposited together with coal during coal formation. It is usually in the form of a thin layer in or on the top or bottom of a coal seam. Due to long-term infiltration and diffusion of the coal seam, it also has a certain carbon content, and the color is blackish gray coal gangue. Coal gangue is a solid waste discharged during mine excavation, mining and coal washing.

[0003] At present, the coal gangue crushing technology has been developed for many years at home and abroad. According to the different properties and particle sizes of coal gangue, the coal 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 are combined into one stage to form a two-stage crushing process.

[0004] After crushing, coal is enriched in the fine particle size, and gangue is enriched in the coarse particle size. Studies have found that after jaw and hammer multiple crushing and screening classification, the smaller the particle size, the lower the ash content, and the higher the calorific value. For the effective utilization of coal gangue, crushing, grinding and sorting process equipment are introduced from the ore processing and machine-made sand preparation industries. However, the existing equipment and process cannot realize the separation of coal gangue, resulting in low utilization rate of coal gangue.

[0005] Coal gangue not only destroys the ecological environment, but also has resource characteristics due to its rich mineral composition and chemical composition and special physical properties. At present, many places adopt the mode of regional distribution of coal mines and power plants to efficiently utilize coal resources. Coal gangue with a calorific value that does not meet the combustion requirements after mining and sorting is used as aggregate for underground filling. Coal gangue with a certain calorific value is mixed with power coal and then burned in power plants, which improves the comprehensive utilization degree of coal gangue.

[0006] The selection mode of the coal gangue for underground filling takes the calorific value of the coal gangue as the evaluation standard, and thus low-calorific-value (calorific value less than 6270 kJ / kg) coal gangue is directly used as filling aggregate, high-calorific-value (calorific value greater than 6270 kJ / kg) coal gangue is mixed with power coal for combustion, the organic matter (especially C element) and inorganic matter of the coal gangue are not effectively separated, the strength of the coal gangue itself and the extraction and separation of the high-calorific-value organic matter are affected, the economic value of the coal gangue itself is not fully utilized, the comprehensive utilization efficiency of the coal gangue is limited, and great waste of coal resources is caused; meanwhile, the high-calorific-value coal gangue is not fully separated from the inorganic matter, and thus a large amount of ash is generated after combustion, the equipment cost of the power plant is increased, and the risk of secondary pollution is increased. SUMMARY

[0007] The application provides a coal gangue separation and disposal system based on calorific value classification and a use method thereof, so as to solve the problem that different components in the coal gangue material for underground filling are difficult to separate in the prior art, and improve the high-value utilization degree of the coal gangue material.

[0008] To solve the above technical problems, the application adopts the following technical scheme:

[0009] A coal gangue separation and disposal system based on calorific value classification, comprising a front conveying unit, a separation and disposal unit, a storage unit, and a central control unit connected with the front three units in an electrical signal mode.

[0010] Preferably, the front conveying unit comprises, in sequence, a dryer, a buffer bin, a conveying and metering device, and a corridor, 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 with an external conveying device, and the other end is connected with a feeding port of the buffer bin; a water condenser is connected with the top of the dryer; the end of the buffer bin away from the feeding port is connected with the conveying and metering device, and the conveying and metering device is further connected with a rock crusher of the separation and disposal unit; and a first iron separator and a second iron separator are respectively arranged at the entrance of the dryer and the discharge port of the buffer bin to adsorb ferromagnetic impurities in the coal gangue.

[0011] Preferably, the buffer bin is provided with a weighing sensor, a height sensor, and a material moisture detector, which measure the coal gangue in the buffer bin, adjust the feeding speed of the coal gangue into the buffer bin, ensure the feeding speed of the coal gangue into the subsequent separation and disposal unit, and maintain the stability of the system disposal level; the material moisture detector is arranged at the discharge port of the buffer bin, feeds back data to the central control unit, and adjusts the operation of the material layer stabilizing device.

[0012] Preferably, the quality separation unit comprises a vertical mill and a dynamic-static classifier, which sprays dry ice as a water condensing agent and a grinding aid stabilizer through the material layer stabilizer arranged inside the vertical mill, and the dynamic-static classifier effectively separates each component of the coal gangue to the storage unit for storage; the quality separation unit also comprises a stone 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-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.

[0013] Preferably, the vertical mill comprises a material falling pipe, a crushing roller, a grinding roller, a material blocking ring, a grinding disc and a material layer stabilizer; the r≤30mm coal gangue particles fall into the center of the grinding disc through the material falling pipe on the top plate of the vertical mill, the grinding disc moves, the coal gangue particles move centrifugally, when reaching the crushing interval, the crushing roller crushes the coal gangue particles, due to the selective crushing characteristics of the material layer, the part with lower hardness in the coal gangue is crushed and separated, then the particles continue to move to the edge of the grinding disc under centrifugal motion, the internal material blocking ring classifies the material layer, the particles with r≥5mm will continue to be crushed by the crushing roller in the crushing area, and the particles with r<5mm pass through the internal material blocking ring and reach the grinding area under centrifugal motion, and are ground by the grinding roller, due to the selective crushing characteristics of the material layer, different hardness particles in the particles are further separated, forming a particle material layer, which moves to the edge of the grinding disc and falls into the material collecting port of the vertical mill, and then is sent into the high-frequency classifier by the conveying equipment.

[0014] Preferably, the material layer stabilizer comprises a support structure for leveling the material layer, one side of the support structure is fixedly connected to the edge of the grinding disc, the other side of the support structure is fixedly connected with an adjusting frame through an electric cylinder, the adjusting frame is connected with a material stabilizing roller at the bottom, a plurality of dry ice nozzles capable of electrically adjusting the jet flow and angle are arranged at the top of the material stabilizing roller, the electric cylinder can drive the adjusting frame to change the height of the material stabilizing roller and the dry ice nozzles, and the dry ice nozzles are connected with a dry ice storage device through a dry ice connecting pipe, wherein the jet direction of the dry ice nozzles of the material layer stabilizer is aligned with the material layer movement path of the grinding disc.

[0015] Preferably, the central control unit collects, analyzes, judges and regulates the data of other working units, so as to ensure the stable function of the system in the separation and treatment of different qualities, and to drive the separation of different qualities by the calorific value of coal gangue and form a closed-loop control; the coal gangue is sent into the separation unit by the pre-conveying unit, and the coal gangue first enters the stone crusher for primary crushing, the stone crusher crushes the material to ≤30mm, and the material is sent into the static classifier by the conveying equipment, the static classifier collects the particles with a particle size r≤0.075mm into the powder collector, and the particles with a particle size r>0.075mm are introduced into the grading screen, a layer of screen with a pore size of 30mm is arranged in the grading screen, the coal gangue with a particle size r>30mm is screened back to the stone crusher for further crushing, the coal gangue with a particle size 0.075mm

[0016] Preferably, the central control unit dynamically controls the dry ice conveying amount of the dry ice storage device according to the data of the material moisture detector at the discharge port of the buffer bin of the pre-conveying unit, combined with the material layer vibration data, to adjust the humidity and stability of the material layer in the vertical mill; the height of the electric cylinder and the spraying flow and angle of the dry ice nozzle are adjusted by the central control unit in real time according to the material layer thickness, and the pressure parameter of the dry ice storage device is linked with the grinding disc speed, when the speed increases to a threshold value, the dry ice spraying amount increases by 10%~15% compared with the previous period.

[0017] Preferably, the storage unit comprises a gangue powder warehouse, a gangue particle warehouse and an aggregate warehouse; the grading logic of the quality separation unit is that the static classifier separates the particles of r≤0.075 mm to the powder collector and the particles of r>0.075 mm to the grading screen; the grading screen is provided with a 30 mm screen, and the particles of 0.075 mm

[0018] A use method of a coal gangue quality separation and disposal system based on heat value classification, comprising the following steps,

[0019] Parameter calibration stage: sampling and heat value analysis of coal gangue, determination of initial heat value, moisture content and hardness distribution, and easy grinding test and parameter setting;

[0020] Pre-processing stage: the central control unit determines the operation parameters of each device of the system according to the heat value, the device is started, the system is operated, the coal gangue raw material enters the quality separation system, and after the water drying and iron removal operation of the pre-conveying unit, it enters the quality separation unit; the coal gangue is conveyed to the first iron remover to remove iron impurities, enters the dryer and then enters the buffer bin; the buffer bin feeds back data through the height sensor and the moisture detector, and the central control unit adjusts the drying temperature and residence time of the dryer to reduce the moisture of the material;

[0021] The coal gangue is respectively sent into the gangue powder warehouse, the gangue particle warehouse and the aggregate warehouse after the crushing, grinding and separation process of the quality separation unit is completed; the crusher crushes the material to be less than or equal to 30 mm, and the crushed material is sent into the static classifier by the conveying equipment; the static classifier collects the particles with a particle size r less than or equal to 0.075 mm into the powder collector, and the particles with a particle size r greater than 0.075 mm are introduced into the grading screen; a 30 mm mesh screen is arranged in the grading screen, and the coal gangue with a particle size r greater than 30 mm is returned to the crusher for further crushing; the coal gangue with a particle size of 0.075 mm to 30 mm is sent into the vertical mill for grinding; the vertical mill realizes the separation of different hardnesses by the layer stabilizing device and the grinding roller, and then the coal gangue with a particle size r greater than 5 mm is returned to the vertical mill for further crushing and grinding by the high-frequency classifier with a 5 mm aperture, and the coal gangue with a particle size r less than 5 mm is sent into the dynamic and static classifier for dynamic and accurate air separation according to the thresholds of 0.08 mm and 0.15 mm.

[0022] The classified storage stage: after the component materials are respectively conveyed to the gangue powder warehouse, the gangue particle warehouse and the aggregate warehouse, the central control unit monitors the material level of each warehouse in real time and records the storage quantity by the intelligent metering system; the material calorific value of the gangue powder warehouse and the gangue particle warehouse is measured by the 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 convey the materials in the gangue powder warehouse and the gangue particle warehouse to the low calorific value material warehouse or the high calorific value material warehouse according to the material preparation scheme set by the system.

[0023] Preferably, in the pre-treatment stage, the residence time is dynamically adjusted according to the initial moisture content of the coal gangue, the drying temperature is 120-180 DEG C, and the generated hot water vapor is recovered by the water condenser.

[0024] According to the above technical scheme, the coal gangue products are classified according to the calorific value, the coal gangue is separated according to the quality, and the calorific value of the gangue powder is improved; the equipment parameters are adjusted based on the calorific value and the particle size, the product is controlled, and the added value of the product is improved; the dry ice is used as the water condensing agent / abrasive, the coal gangue can be better separated, the material layer is stabilized, the effective separation of the components of the coal gangue is realized by the above innovative points, the added value of the coal gangue product is improved, the disposal scale of the coal gangue and the downstream product market are expanded, and the environmental pollution is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 The system unit of the present application is shown in the block diagram;

[0026] Figure 2 The conveying unit, the quality separation unit, the storage unit and the central control unit module of the present application are shown in the block diagram;

[0027] Figure 3Structure schematic diagram of vertical mill of the embodiment of the present application;

[0028] Figure 4 Function schematic diagram of gangue crushing area of vertical mill of the embodiment of the present application;

[0029] Figure 5 Function schematic diagram of gangue grinding area of vertical mill of the embodiment of the present application;

[0030] Figure 6 Motion schematic diagram of gangue on the grinding disc of vertical mill of the embodiment of the present application;

[0031] Figure 7 Structure schematic diagram of material layer stabilizing device of vertical mill of the embodiment of the present application;

[0032] Figure 8 Use schematic diagram of material layer stabilizing device of vertical mill of the embodiment of the present application;

[0033] Figure 9 Carbon element distribution diagram of raw coal gangue before disposal of the embodiment of the present application;

[0034] Figure 10 Carbon element distribution diagram of coal gangue liver powder after disposal of the embodiment of the present application.

[0035] In the figure: 1, front conveying unit; 101, dryer; 102-01, first iron remover; 102-02, second iron remover; 103, buffer bin; 104, conveying and metering device; 105, water condenser; 2, quality separation unit; 201, stone crusher; 202, static classifier; 203, classification screen; 204, vertical mill; 205, high-frequency classifier; 206, dynamic and static classifier; 207, powder collector; 208, material falling pipe; 209, grinding roller; 210, grinding disc; 211, material blocking ring; 212, crushing roller; 213, material layer stabilizing device; 214, support 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

[0036] In order to make the technical means, creative features, purposes and effects realized by the present application easy to understand, the present application is further described below in combination with specific embodiments.

[0037] Embodiment: as Figures 1-10As shown, the coal gangue quality separation and disposal system based on calorific value classification comprises a front conveying unit 1, a quality separation unit 2, a storage unit 3, and a central control unit 4 connected with the first three units in an electrical signal mode; the central control unit 4 collects, analyzes, judges and controls the data of each working unit, ensures the stability of the quality separation and disposal function, and drives the quality separation through the calorific value of the coal gangue and forms a closed-loop control.

[0038] Specifically, the front conveying unit 1 comprises a dryer 101, a buffer bin 103, a conveying and 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 can monitor and feed back data to the central control unit 4 in real time; one end of the dryer 101 is connected with an external conveying device, and the other end is connected with a feeding port of the buffer bin 103; a water condenser 105 is connected to the top of the dryer 101; the end of the buffer bin 103 away from the feeding port is connected with the conveying and metering device 104, and the conveying and metering device 104 is further connected with a rock crusher 201 of the quality separation unit 2; first and second iron removers 102-01 and 102-02 are respectively installed at the entrance of the dryer 101 and the discharge port of the buffer bin 103 to adsorb the ferromagnetic impurities in the coal gangue.

[0039] In the embodiment, the quality separation unit 2 comprises a vertical mill 204 and a dynamic-static classifier 206, which sprays dry ice as a water condensing agent and a grinding aid through a material layer stabilizing device 213 arranged inside the vertical mill 204, and the spraying direction is the same as the rotating direction of a grinding disc 210 of the vertical mill 204, so as to stabilize the material layer (mainly in terms of water content and vibration); the vertical mill 204 can be additionally provided with a dry ice adding device and a gas recycling device to recycle the gas; the dynamic-static classifier 206 effectively separates each component of the coal gangue by using wind power and saves them in the storage unit 3 respectively; the quality separation unit 2 further comprises a rock 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-static classifier 206 arranged at the rear end of the vertical mill 204; the static classifier 202 is connected with a powder collector 207 through a conveying device, and the high-frequency classifier 205 is connected with the vertical mill 204 through another set of conveying devices.

[0040] Specifically, the vertical mill 204, for example, Figures 3-6As shown, including blanking tube 208, grinding roller 209, grinding disc 210, blocking ring 211, broken roller 212 and material layer stabilizing device 213, r≤30mm (here and hereinafter, r is the particle size of coal gangue) coal gangue particles fall through the blanking tube 208 on the top plate of the vertical mill 204 to the center position of the grinding disc 210, the grinding disc 210 rotates, the coal gangue particles undergo centrifugal motion, when reaching the crushing zone (i.e. the position interval in which the broken roller 212 can crush the coal gangue particles), the broken roller 212 crushes the coal gangue particles, because of the selective crushing characteristics of the material layer, i.e. the phenomenon of non-uniform crushing of the material in the crushing process due to the hardness, brittleness or structural differences between particles under the action of external mechanical force (such as extrusion, shearing, impact), the hardness of the organic matter in the coal gangue is low (1-2), which is crushed and separated, the hardness of the inorganic matter is high (hardness 4-7), which produces interface microcracks, the coal gangue particles form a material layer under the action of centrifugal force, low-hardness coal particles are preferentially crushed into fine powder, high-hardness gangue particles remain large in size, a blocking ring 211 is arranged between the crushing zone and the grinding zone, wherein the blocking ring 211 is provided with a 5mm screen, and the crushed particles with a particle size r≤5mm can pass through the gap of the blocking ring 211 to reach the grinding zone (i.e. the position interval in which the grinding roller 209 can grind the coal gangue particles) and are ground by the grinding roller 209, and the different hardness inorganic matter and organic matter carbon inside the particles are further separated under the low-temperature brittle aid of dry ice, the organic matter is separated from the gangue matrix, and as the material layer moves to the edge of the grinding disc 210, it falls into the material collecting port of the vertical mill 204, and then is sent into the high-frequency classifier 205 by a conveying device to realize physical separation; through selective crushing, the coal gangue is divided into gangue powder (r≤0.08mm, rich in 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.

[0041] Specifically, the material layer stabilizing device 213, as shown in Figure 7 As shown, the support structure 214 for leveling the material layer is fixedly connected to one side of the edge of the grinding disc 210, the other side of the support structure 214 is fixedly connected with an adjusting frame through an electric cylinder, the bottom of the adjusting frame is connected with a material stabilizing roller 215, according to the required thickness of the material layer, the adjusting frame can adjust the height of the material stabilizing roller 215 from the grinding disc 210 through the electric cylinder, the top of the material stabilizing roller 215 is fixedly connected with a plurality of dry ice nozzles 216, the dry ice nozzles 216 are connected with a dry ice storage device 218 through a dry ice connecting pipe 217, wherein the dry ice nozzles 216 of the material layer stabilizing device 213 are aligned with the material layer movement path of the grinding disc 210.

[0042] In this embodiment, as shown in Figures 7-8The core mechanism of the material layer stabilizing device 213 is to use the heat absorption of dry ice evaporation to achieve temperature regulation and brittleness enhancement, powder flow optimization, and control of material layer thickness and density. The low-temperature embrittlement effect (after dry ice (-78.5°C) is sprayed to the coal gangue material layer, the material temperature is rapidly reduced by about 573 kJ / kg through sublimation heat absorption, causing micro-cracks in the organic matter such as residual coal and inorganic matter such as clay minerals in the coal gangue due to the difference in thermal expansion coefficient, and the hardness is reduced by 20%-40%), selective crushing promotion (organic matter is more prone to brittle at low temperature, and preferentially breaks during grinding, achieving efficient dissociation of organic matter and gangue matrix), lubricating effect of dry ice particles (dry ice particles with a particle size of 0.5-2 mm act as "micro bearings" in the material layer, reducing the friction coefficient between particles by 30%-50% and preventing material adhesion to the grinding disc), static electricity elimination (CO2 gas generated by dry ice sublimation can neutralize static electricity on the surface of the powder, avoiding uneven material layer caused by fine powder agglomeration), and dynamic compensation mechanism (the material layer state is monitored in real time through weighing sensors and vibration sensors; that is, the central control unit 4 needs to adjust the dry ice injection amount according to the porosity feedback of the material layer, and when the porosity is >40%, the dry ice injection amount is increased to fill the voids; when the porosity is <25%, the dry ice is reduced to avoid excessive compaction).

[0043] The central control unit 4 dynamically controls the dry ice delivery amount of the dry ice storage device 218 according to the data of the material moisture detector at the discharge port of the buffer bin 103 of the pre-conveying unit 1, combined with the vibration data of the material layer, to adjust the humidity and stability of the material layer in the vertical mill 204; the injection flow and angle of the height dry ice nozzle 216 of the electric cylinder are adjusted in real time by the central control unit 4 according to the material layer thickness, and the pressure parameter of the dry ice storage device 218 is linked with the rotation speed of the grinding disc 210, and when the rotation speed increases to a threshold value, the dry ice injection amount increases by 10%-15%.

[0044] Specifically, the storage unit 3 includes a gangue powder warehouse 301, a gangue particle warehouse 302, and an aggregate warehouse 303; wherein the grading logic of the quality separation unit 2 is: the static classifier 202 separates r≤0.075 mm particles to the powder collector 207, and r>0.075 mm particles to the grading screen 203; the grading screen 203 is provided with a 30 mm screen, and r>30 mm stones are returned to the stone crusher 201, and r≤30 mm particles enter the vertical mill 204; the high-frequency classifier 205 is provided with a 5 mm screen, and r≥5 mm particles are returned to the vertical mill 204, and r<5 mm particles enter the dynamic-static classifier 206; the dynamic-static classifier 206 sorts particles according to particle size: r≤0.08 mm to the gangue powder warehouse 301, 0.08

[0045] Specifically, the storage unit 3 further comprises a conveying device 306, the gangue powder warehouse 301 and the gangue particle warehouse 302 are provided with online calorific value detection devices, the online calorific value detection devices and the conveying device 306 are electrically connected to the central control unit 4, the conveying device 306 is connected with the high-calorific-value material warehouse 304 and the low-calorific-value material warehouse 305, the online calorific value detection devices 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, and the central control unit 4 determines whether to convey 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 conveying device 306 according to the preset value.

[0046] A use method of a coal gangue separation and disposal system, comprising the following steps:

[0047] S1, parameter calibration stage: coal gangue sampling and calorific value analysis, determination of initial calorific value, moisture content and hardness distribution, and easy grinding test and parameter setting, it should be noted that different batches of coal gangue need to be resampled and calorific value analyzed before entering the system; specifically including:

[0048] S1.1: randomly sample 2 kg of coal gangue entering the system, crush it with a jaw crusher, screen it with different particle size standard screens, and collect the gangue particles in different particle size intervals, numbered x1, x2, x3…xn, respectively measure their calorific values and record Qx1, Qx2, Qx3…Qxn. Let Q0(x) = ;

[0049] S1.2: determine the easy grinding of coal gangue according to GB / T cement easy grinding method, and record G(x), let the running standard parameter array of the coal gangue separation and disposal system be Ps= , then the system running parameter array can be obtained according to the related initial parameters:

[0050]

[0051] Wherein μ(x) is a correction function for the calorific value of gangue in different particle size intervals,

[0052]

[0053] Wherein is the average particle size of a certain particle size interval, is the expected optimal particle size of the system, is the reference calorific value of coal gangue, since μ(x) is obtained according to the data quantity of the production system, it also needs to be adjusted in time according to the following three stages.

[0054] S2, pre-treatment stage: the central control unit 4 determines the operating parameters of each device in the system according to the calorific value, the device is started, the system is running, the coal gangue raw material enters the quality separation system, and after the moisture drying and iron removal operation of the pre-conveying unit 1, it enters the quality separation unit 2; specifically including:

[0055] S2.1: the central control unit 4 determines the operating parameters of each device in the system according to the calorific value, the device is started, and the system is running;

[0056] S2.2: the coal gangue is conveyed to the first iron remover 102-01 to remove iron impurities, enters the dryer 101, and then enters the buffer bin 103; the buffer bin 103 feeds back data through the height sensor and the moisture detector, and the central control unit 4 adjusts and controls the drying temperature and the residence time of the dryer 101 to reduce the moisture of the material, wherein the residence time is dynamically adjusted according to the initial moisture content of the coal gangue, the drying temperature is 120℃~180℃, and the generated hot water vapor is recovered by the water condenser 105;

[0057] S2.3: the dried coal gangue material enters the buffer bin 103, and after the coal gangue temperature cools to 60℃, it is sent out of the pre-conveying unit 1 by the conveying and metering device 104 after passing through the second iron remover 102-02.

[0058] S3, quality separation stage: the coal gangue completes the crushing, grinding and separation process after passing through the quality separation unit 2, and respectively enters the gangue powder warehouse 301, the gangue particle warehouse 302 and the aggregate warehouse 303 of the storage unit 3; specifically including:

[0059] S3.1: the coal gangue from the pre-conveying unit 1 enters the stone crusher 201 for the first crushing, the stone crusher 201 crushes the material to ≤30mm, and uses the conveying equipment to enter the static classifier 202, the static classifier 202 collects the particles with a particle size r≤0.075mm into the powder collector 207, and the particles with a particle size r>0.075mm are introduced into the grading screen 203, which is provided with a layer of 30mm mesh screen, and the coal gangue block with a particle size r>30mm is returned to the stone crusher 201 for further crushing;

[0060] S3.2: the coal gangue particles with a particle size of 0.075mm

[0061] S3.3: The coal gangue particles with particle size r < 5 mm enter the dynamic-static classifier 206, and the dynamic-static classifier 206 performs wind separation according to particle size, r ≤ 0.08 mm to the gangue powder warehouse 301, 0.08 mm < r ≤ 0.15 mm to the gangue particle warehouse 302, and 0.15 < r < 5 mm to the aggregate warehouse 303.

[0062] S4, classification and storage stage: after the component materials are respectively transported to the gangue powder warehouse 301, the gangue particle warehouse 302 and the aggregate warehouse 303 of the corresponding storage unit 3, the central control unit 4 monitors the material level of each warehouse in real time through the intelligent metering system and records the storage quantity; the material calorific value of the gangue powder warehouse 301 and the gangue particle warehouse 302 is determined through the online calorific value detection equipment, and the result is transmitted to the central control unit 4, and 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 the gangue particle warehouse 302 to the low calorific value material warehouse 305 or the high calorific value material warehouse 304 according to the system set material preparation scheme; specifically including:

[0063] S4.1: The calorific value of the materials in the gangue powder warehouse 301 and the gangue particle warehouse 302 is tested through the online calorific value detection equipment (the specific model can be selected according to actual demand and budget in table 1 and other equipment that can replace any equipment in table 1), and the calorific value Q i1 , Q i2 is recorded respectively, and according to the content of table 2, whether the value of Q i1 , Q i2 is 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 to the high calorific value material warehouse 304 or the low calorific value material warehouse 305 by the transportation equipment 306, for example: if the calorific value detection result of the gangue powder warehouse 301 is Q i1 ≥6270kJ / kg, the materials in the gangue powder warehouse 301 need to be transported to the high calorific value material warehouse 304 by the transportation equipment 306, and if Q i1 <6270kJ / kg, it is transported to the low calorific value material warehouse 305.

[0064] Table 1: Mainstream online calorific value detection equipment types and indicators

[0065]

[0066] Note: The above each type of online calorific value detection equipment can meet the judgment scene of the calorific value of coal gangue being greater than or less than 6270kJ / kg, among them, the LIBS equipment has faster response time, and is more suitable for the use scene of the present application, and can be preferentially selected.

[0067] Table 2: Gangue powder warehouse and gangue particle warehouse calorific value judgment

[0068]

[0069] S4.2: Determine the mass specific gravity of the materials in the gangue powder warehouse 301, the gangue particle warehouse 302 and the aggregate warehouse 303 by the respective finished product warehouse weighing device, and record the specific gravity as k i1 , k i2 , k i3 ;

[0070] S4.3: Calculate the value of , and determine which material is suitable for making and outputting according to the control content of Table 3, understand the material properties (high and low calorific value materials, aggregates) and their respective proportions, for example, the number D2 in the following table, Q i > 0, K = 0, which means that the batch of coal gangue can be used to prepare high calorific value materials (gangue powder and gangue particles) and aggregates, and the proportions of the two are the same.

[0071] Table 3 Control parameter group table of coal gangue quality separation and disposal system

[0072]

[0073] In this embodiment, "S1, parameter calibration stage" of a use method based on a coal gangue quality separation and disposal system. Every time a batch of coal gangue is replaced, the coal gangue sample preparation and parameter calibration experiment need to be performed again. The parameter formula is calibrated and corrected to optimize the operation parameters of the coal gangue quality separation system. The specific test process is as follows:

[0074] Step 1: Sample grouping and pretreatment. Select the same batch of coal gangue raw materials, preliminarily crush them by a jaw crusher (model PE-250x400), and then sieve them into 5 groups of particle size intervals (0~1mm, 1~3mm, 3~5mm, 5~8mm, 8~10mm) using a standard sieve (GB / T 6003.1-2022 "Test Sieve Technical Requirements and Inspection Part 1: Metal Wire Mesh Test Sieve") and record the average particle size . Further divide each group of particle size samples into 3 subgroups by mixing high calorific value coal gangue ≥ 6.27 MJ / kg) or low calorific value coal gangue ≤ 6.27 MJ / kg), adjust the calorific value of the subgroups to low (1.5~2.09 MJ / kg), medium (2.09~6.27 MJ / kg) and high (6.27~12.25 MJ / kg) levels to ensure that the calorific value gradient covers the actual working condition range.

[0075] Step 2: Key parameter determination. Calorific value determination: according to GB / T213-2008 "Coal Calorific Value Determination Method", use an oxygen bomb calorimeter (model ZDHW-8) to determine the calorific value of each subgroup , accurate to 0.1 MJ / kg; the grindability test: according to GB / T26567-2011 "Cement raw material grindability test method", the Bond work index G(x) is determined by using a Φ305*305mm standard ball mill, unit kWh / t; system operation parameter collection: each sub-group of coal gangue is input into the quality separation system, and the actual operation parameters (including vertical mill 204 main motor speed, powder concentrator main motor speed, feeding speed, etc.) are recorded.

[0076] Step 3: Data acquisition and processing. Each group of experiments was repeated 3 times, a total of 45 groups of data (5 groups of particle size * 3 groups of calorific value * 3 times of repetition) were obtained, and the mean value was taken after eliminating abnormal values, and finally the reference value was set as: = 0.5mm (median particle size), = 15 MJ / kg (industry benchmark value).

[0077] 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 the fitting k=1.25, α=0.68, β=0.15 is obtained, and the fitting determination coefficient R 2 = 0.92.

[0078] Verification: randomly select 20% of the data (9 groups) for cross-validation, and the prediction error is ≤8%, which meets the engineering precision requirements.

[0079] Implementation effect: after parameter calibration, the calculation error of the system operation parameter is reduced from 22% of the original model to 9%, which significantly improves the system quality separation efficiency and energy consumption control precision;

[0080] In this embodiment, the product element energy spectrum detection is performed on the coal gangue raw material, the low calorific value material library 305 and the high calorific value material library 304. The Summagraphics QuattroS equipped with a field emission electron gun (with a spatial resolution of nanometer level) is suitable for micro-area element analysis, and the EDAX ELECTPLUS energy spectrometer can realize fast surface scanning and element distribution imaging, and the carbon element distribution diagram as shown in Figure 9 and Figure 10 is obtained. The calorific value of the sample is determined through testing, and the following two tables 4 and 5 are obtained for reference.

[0081] Table 4 Element weight and calorific value of coal gangue raw material

[0082]

[0083] Table 5 Element weight and calorific value of coal gangue powder library material

[0084]

[0085] The above described embodiments are merely intended to describe the preferred embodiments of the present application, and are not intended to limit the scope of the present application, and various modifications and improvements made by those skilled in the art to the technical solutions of the present application without departing from the design spirit of the present application shall fall within the protection scope of the present application as defined by the claims.

Claims

1. A coal gangue separation and disposal system based on calorific value classification, characterized in that: It comprises a front conveying unit (1), a quality separation unit (2), a storage unit (3), and a central control unit (4) electrically connected with the former three units respectively; The quality separation unit (2) comprises a vertical mill (204) and a dynamic-static classifier (206), the vertical mill (204) is provided with a material layer stabilizing device (213) inside, dry ice is sprayed to the rotating direction of the grinding disc (210) of the vertical mill (204) through the material layer stabilizing device (213) to stabilize the material layer, and the dynamic-static classifier (206) separates each component of the coal gangue by using wind power and saves them in the storage unit (3) respectively; The central control unit (4) collects, analyzes, judges and controls the data of each working unit, ensures the stability of the quality separation disposal function, drives the quality separation by the calorific value of the coal gangue, and forms a closed loop control. The material layer stabilizing device (213) comprises 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), the other side of the support structure (214) is fixedly connected with an adjusting frame through an electric cylinder, the adjusting frame is connected with a material stabilizing roller (215) at the bottom, the top of the material stabilizing roller (215) is fixedly connected with a plurality of dry ice nozzles (216) capable of electrically adjusting the spraying flow and angle, the dry ice nozzles (216) are connected with a dry ice storage device (218) through a dry ice connecting pipe (217), and the spraying direction of the dry ice nozzles (216) of the material layer stabilizing device (213) is the same as the movement path of the material layer of the grinding disc (210). The height of the electric cylinder and the spraying flow and angle of the dry ice nozzles (216) are adjusted in real time by the central control unit (4) according to the thickness of the material layer, and the spraying pressure parameter of the dry ice storage device (218) of the material layer stabilizing device (213) is linked with the rotating speed of the grinding disc (210) of the vertical mill (204).

2. The coal gangue classified separation and disposal system based on calorific value classification according to claim 1, characterized in that: The quality separation unit (2) further comprises a stone crusher (201), a static classifier (202), a grading screen (203) and a high-frequency classifier (205) arranged in sequence in front of the vertical mill (204), and the high-frequency classifier (205) is connected to the vertical mill (204) through another set of conveying devices.

3. The coal gangue classified separation and disposal system based on calorific value classification according to claim 2, characterized in that: The central control unit (4) dynamically controls the dry ice conveying amount of the dry ice storage device (218) according to the data of the material moisture detector at the discharge port of the buffer bin (103) of the front conveying unit (1) and in combination with the material layer vibration data, so as to adjust the humidity and stability of the material layer in the vertical mill (204).

4. The coal gangue classified separation and disposal system based on calorific value classification according to claim 3, characterized in that: The storage unit (3) comprises a gangue powder warehouse (301), a gangue particle warehouse (302) and an aggregate warehouse (303); the grading logic of the quality separation unit (2) is as follows: The static classifier (202) separates the particles with a particle size of r≤0.075 mm to the powder collector (207) and the particles with a particle size of r>0.075 mm to the grading screen (203). The grading screen (203) is provided with a 30 mm screen, and the particles of 0.075 mm < r ≤ 30 mm enter the vertical mill (204), and the stone of r > 30 mm returns to the stone crusher (201); The high-frequency classifier (205) is provided with a 5 mm screen, and the particles of r < 5 mm enter the dynamic-static classifier (206), and the particles of r ≥ 5 mm return to the vertical mill (204); The dynamic-static classifier (206) is wind force sorted according to particle size: r ≤ 0.08 mm to the gangue powder warehouse (301), 0.08 mm < r ≤ 0.15 mm to the gangue particle warehouse (302), and 0.15 < r < 5 mm to the aggregate warehouse (303); Wherein, r is the particle size of coal gangue, according to the above logic, the quality separation unit (2) screens particles of different particle sizes into the corresponding warehouse of the storage unit (3).

5. The coal gangue classified separation and disposal system based on calorific value classification according to claim 4, characterized in that: The storage unit (3) further comprises 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, and the online calorific value detection device and the transportation device (306) are both electrically connected to the central control unit (4), and the transportation device (306) is connected with the high-calorific value material warehouse (304) and the low-calorific value material warehouse (305).

6. The coal gangue classified separation and disposal system based on calorific value classification according to claim 2, characterized in that: The front conveying unit (1) comprises 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 monitor and feed back data to the central control unit (4) in real time, one end of the dryer (101) is connected with an external conveying device, the other end is connected with the inlet of the buffer bin (103), the top of the dryer (101) is connected with a water condenser (105), the end of the buffer bin (103) away from the inlet is connected with the conveying metering device (104), the conveying metering device (104) is also connected with the stone crusher (201) of the quality separation unit (2), and first and second iron removers (102-01, 102-02) are respectively installed at the entrance of the dryer (101) and the discharge port of the buffer bin (103) to adsorb ferromagnetic impurities in the coal gangue.

7. The method of using the coal gangue separation and disposal system based on calorific value classification according to any one of claims 1-6, characterized in that: The method comprises the following steps, Parameter calibration stage: coal gangue sampling and calorific value analysis, determination of initial calorific value, moisture content and hardness distribution, and easy grinding test and parameter setting; Front pretreatment stage: the central control unit (4) determines the operating parameters of each device of the system according to the calorific value, the device is started, the system is operated, the coal gangue raw material enters the quality separation system, and after the moisture drying and iron removal operation of the front conveying unit (1), enters the quality separation unit (2); Quality separation stage: the coal gangue enters the gangue powder warehouse (301), the gangue particle warehouse (302) and the aggregate warehouse (303) of the storage unit (3) after completing the crushing, grinding and sorting processes in the quality separation unit (2); Classification storage stage: after the component materials are respectively transported to the gangue powder warehouse (301), the gangue particle warehouse (302) and the 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 material calorific value of the gangue powder warehouse (301) and the gangue particle warehouse (302) is determined through 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 the gangue particle warehouse (302) to the low-calorific value material warehouse (305) or the high-calorific value material warehouse (304) according to the system set material preparation scheme.

8. The method of using the coal gangue classified separation and disposal system based on calorific value classification according to claim 7, characterized in that: In the pre-treatment stage, the residence time is dynamically adjusted according to the initial moisture content of the coal gangue, the drying temperature is 120-180℃, and the hot water vapor generated is recovered through the water condenser (105).

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