System and method for separating clean coal and pyrite from coal gangue

Abstract

The present invention relates to the field of coal gangue processing technology, and in particular to a system and method for sorting clean coal and pyrite in coal gangue, comprising a pretreatment mechanism, a screening mechanism, a sample analysis mechanism, and an intelligent sorting mechanism, wherein the intelligent sorting mechanism comprises a frame body, a first sorting section, a second sorting section, and an execution controller, wherein the first sorting section and the second sorting section are sequentially arranged on the frame body from top to bottom, and the execution controller is used to control the first sorting section and the second sorting section to sort the ore; the pretreatment mechanism, the screening mechanism, and the intelligent sorting mechanism are sequentially connected, and the sample analysis mechanism is communicatively connected to the execution controller. The sorting system first screens and grades the coal gangue according to the presence form of pyrite in the coal gangue, and then intelligently sorts the graded coal gangue, effectively solving the problems of low grade, low sorting efficiency, and difficulty in large-scale production in the process of directly selecting coal and pyrite in coal gangue mainly by gravity separation and flotation.

Description

Technical Field

[0001] The present invention relates to the technical field of coal gangue processing, in particular to a system and method for separating clean coal and pyrite from coal gangue. Background Art

[0002] Gangue is solid waste produced during coal mining and washing. Large-scale stockpiling not only wastes land resources but also poses serious environmental risks, including spontaneous combustion, rain damage, and mudification. Therefore, addressing the environmental pollution caused by gangue and strengthening research on its comprehensive management and utilization are key areas of research for major coal-burning countries and are essential for environmental protection and development.

[0003] The coal gangue discarded in my country every year still contains a few percent to more than 20 percent of coal and about 3% of pyrite. How to extract coal and pyrite from coal gangue and turn it into treasure is an effective way to achieve the harmless, reduced and resource-based treatment of solid waste, which not only has significant social and economic benefits, but also has huge environmental benefits.

[0004] Recovering the coal and pyrite from the gangue not only saves energy and increases economic benefits, but is also crucial for ensuring the quality of products used in gangue construction and chemical applications, and for stabilizing production processes and operating methods. Furthermore, using gravity separation (jigging, shaking tables, chutes) and flotation to separate pyrite and coal from gangue has a positive impact on improving the grade and separation efficiency of the selected materials, while reducing grinding costs and environmental remediation costs.

[0005] Chinese invention patent CN101890395A discloses a method for extracting coal and pyrite from coal gangue. This method utilizes traditional mineral processing techniques, using different separation agents and controlled flotation time, first selecting sulfur and then selecting coal. The method achieves a pyrite grade of 32 or higher, a coal calorific value of 5,600 cal / kg or higher, and a total recovery rate of pyrite and coal exceeding 50%. However, this method requires large amounts of lime and copper sulfate as a conditioning agent, consumes high processing energy, and cannot achieve intelligent separation.

[0006] In view of this, the present invention is proposed. Summary of the Invention

[0007] The purpose of the present invention is to provide a system and method for separating clean coal and pyrite from coal gangue. The system performs graded sorting on the coal gangue, solving the problems of low grade, low sorting efficiency, small processing capacity, high grinding cost, high environmental management cost, and difficulty in large-scale production in traditional processes.

[0008] In a first aspect, the present invention provides a system for separating clean coal and pyrite from coal gangue, comprising a pretreatment mechanism, a screening mechanism, a sample analysis mechanism, and an intelligent sorting mechanism.

[0009] The intelligent sorting mechanism includes a frame body, a first sorting part, a second sorting part, and an execution controller. The first sorting part and the second sorting part are sequentially arranged on the frame body from top to bottom. The execution controller is used to control the first sorting part and the second sorting part to sort the ore.

[0010] The pretreatment mechanism, the screening mechanism and the intelligent sorting mechanism are connected in sequence, and the sample analysis mechanism is communicatively connected with the execution controller.

[0011] As a preferred embodiment of the present technical solution, the intelligent sorting mechanism further includes a vibrating feeder and a feeding conveyor belt. The vibrating feeder and the feeding conveyor belt are both arranged on the frame body, and the feeding conveyor belt is arranged below the vibrating feeder.

[0012] As a preferred embodiment of the present technical solution, the first sorting part includes a first X-ray identification device, a first airflow separator and a clean coal funnel, the transmitting end of the first X-ray identification device is vertically pointed at the feeding surface of the feeding conveyor belt, the receiving end of the first X-ray identification device is located directly below the feeding surface of the feeding conveyor belt, the signal output end of the first X-ray identification device is connected to the execution controller, the first airflow separator is connected to the execution controller, and the clean coal funnel is arranged below the first airflow separator.

[0013] As a preferred embodiment of the present technical solution, the second sorting section includes a second X-ray identification device, a second airflow separator, a clean coal gangue hopper and a pyrite hopper. The second X-ray identification device is arranged on the frame body and is located below the feeding conveyor belt. The transmitting end and the receiving end of the second X-ray are arranged opposite to each other and both point to the residual material after sorting by the first sorting section. The signal output end of the second X-ray identification device is connected to the execution controller, the second airflow separator is connected to the execution controller, and the clean coal gangue hopper and the pyrite hopper are adjacently arranged below the second airflow separator.

[0014] As a preferred embodiment of the present technical solution, the first air flow separator is arranged at 100-300 mm below the feeding conveyor belt, and the second air flow separator is arranged at 1200-1400 mm below the feeding conveyor belt.

[0015] As a preferred embodiment of the present technical solution, it further comprises an air supply device, and both the first air flow separator and the second air flow separator are connected to the air supply device.

[0016] As a preferred embodiment of the present technical solution, the screening mechanism includes a screening conveyor belt, a first screening belt, a second screening belt and a receiving belt, the second screening belt is arranged below the first screening belt, and the receiving belt is arranged below the second screening belt.

[0017] As a preferred embodiment of the present technical solution, the pretreatment mechanism includes a crushing device and a grinding device.

[0018] As a preferred embodiment of the present technical solution, negative pressure dust hoods are provided at the discharge port of the feeding conveyor belt, the blowing port of the first air flow separator and the blowing port of the second air flow separator.

[0019] In a second aspect, the present invention further provides a method for separating clean coal and pyrite using the above-mentioned system for separating clean coal and pyrite from coal gangue, which specifically comprises the following steps:

[0020] S1. Remove debris from the coal gangue and perform crushing and grinding pretreatment in sequence;

[0021] S2. Sieving the pre-treated coal gangue with a particle size of less than 60 mm into three particle sizes: 25-60 mm, 6-25 mm, and less than 6 mm;

[0022] S3. Take ore samples of two particle sizes (25-60 mm and 6-25 mm) and conduct ore analysis, imaging analysis, and model analysis in the sample analysis unit respectively;

[0023] S4. The model analysis results are transmitted to the execution controller, and the samples of the two particle sizes of 25-60mm and 6-25mm are successively transmitted to the intelligent sorting mechanism. After sorting in the first sorting section and the second sorting section, clean coal, clean coal gangue and pyrite are obtained.

[0024] As a preferred embodiment of the present technical solution, in step S3, during the raw ore analysis, representative ore samples of two particle sizes (25-60 mm and 6-25 mm) are divided into four types of ore samples: clean coal, high-sulfur-containing grade, medium-sulfur-containing grade, and low-sulfur-containing grade, based on the distribution of clean coal and pyrite in the coal gangue, using an ore density detector and visual observation. The calorific value, sulfur content, and iron content of the four ore samples are then assayed separately.

[0025] In step S3, during the imaging analysis, X-ray imaging is performed on the four ore sample distributions, and multi-angle imaging is performed on each ore sample to obtain a multi-angle imaging group for each ore sample;

[0026] In step S4, during the model analysis, the imaging groups obtained in the imaging analysis are analyzed, and the imaging groups of sulfur content and calorific value in the ore sample are model-integrated based on the imaging differences.

[0027] As a preferred embodiment of the present technical solution, in step S4, in the intelligent sorting mechanism, the first X-ray identification device continuously photographs the gangue passing through the feeding conveyor belt, and the photographed images are saved and transmitted to the execution controller for analysis and processing. The execution controller controls the air volume of the first air flow sorter on the gangue according to the processing results, and sorts out clean coal and residual material; the second X-ray identification device continuously photographs the residual material, and the photographed images are saved and transmitted to the execution controller for analysis and processing. The execution controller controls the air volume of the second air flow sorter on the gangue according to the processing results, and sorts out clean gangue and pyrite.

[0028] The system and method for separating clean coal and pyrite from coal gangue of the present invention have at least the following technical effects:

[0029] 1. The system for separating clean coal and pyrite from gangue of the present invention comprises a pretreatment mechanism, a screening mechanism, a sample analysis mechanism and an intelligent sorting mechanism, wherein the pretreatment mechanism is mainly used to remove impurities from the gangue and to crush and grind the gangue; the screening mechanism is arranged downstream of the pretreatment mechanism and is mainly used to screen the gangue with a particle size of less than 60 mm after pretreatment into three particle sizes of 25-60 mm, 6-25 mm and less than 6 mm. The gangue with a particle size of less than 6 mm has a higher coal content and a calorific value of more than 2500 The sample analysis mechanism analyzes ore samples of two particle sizes (25-60mm and 6-25mm) and transmits the analysis results to the execution controller of the intelligent sorting mechanism. The intelligent sorting mechanism consists of a first sorting section, a second sorting section, and an execution controller. Based on the sample analysis results and the collected data from the first and second sorting sections, the execution controller sequentially sorts the 5-60mm and 6-25mm particle sizes of coal gangue, ultimately yielding clean coal, clean coal gangue, and pyrite. This sorting system enables the intelligent separation of clean coal, clean coal gangue, and pyrite from coal gangue, significantly reducing resource and energy consumption.

[0030] 2. When sorting 25-60mm particle size coal gangue, the present invention achieves a clean coal sorting yield of greater than 2.5%, a low calorific value of approximately 5600kcal / kg, and a desulfurization sorting yield of approximately 20% for ore with a sulfur grade higher than 1%, with an S grade of approximately 4.5%. When sorting 6-25mm particle size coal gangue, the clean coal yield is greater than 3%, a low calorific value of approximately 2974kcal / kg, and a desulfurization sorting yield of approximately 7.6% for ore with a sulfur grade higher than 1%, with an S grade of approximately 6%. The sorting system first screens and grades the coal gangue based on the presence of pyrite in the coal gangue, and then intelligently sorts the graded coal gangue, effectively solving the problems of the process of directly selecting coal and pyrite from coal gangue based on gravity separation and flotation, which have low selection grade, low sorting efficiency, low processing capacity, high grinding costs, high environmental management costs, and difficulty in large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0032] Figure 1 Schematic diagram of a system for separating clean coal and pyrite from coal gangue of the present invention;

[0033] Figure 2 Schematic diagram of the intelligent sorting mechanism of the present invention.

[0034] Description of reference numerals:

[0035] 1: Pretreatment mechanism; 2: Screening mechanism; 3: Sample analysis mechanism; 4: Intelligent sorting mechanism; 5: Frame body; 6: Execution controller; 7: Vibrating feeder; 8: Feeding conveyor belt; 9: First X-ray identification device; 10: First air flow separator; 11: Clean coal hopper; 12: Second X-ray identification device; 13: Second air flow separator; 14: Clean coal gangue hopper; 15: Pyrite hopper; 16: Air supply device. DETAILED DESCRIPTION

[0036] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the embodiments. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0037] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operate in a specific direction, and therefore should not be understood as limiting the present invention.

[0038] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined. In addition, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a communication between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0039] Example 1

[0040] like Figure 1-2 As shown, this embodiment provides a system for sorting clean coal and pyrite in coal gangue, including a pretreatment mechanism 1, a screening mechanism 2, a sample analysis mechanism 3 and an intelligent sorting mechanism 4, wherein the intelligent sorting mechanism 4 includes a frame body 5, a first sorting part, a second sorting part and an execution controller 6, the first sorting part and the second sorting part are arranged on the frame body 5 in sequence from top to bottom, and the execution controller 6 is used to control the first sorting part and the second sorting part to sort the ore; the pretreatment mechanism 1, the screening mechanism 2 and the intelligent sorting mechanism 4 are connected in sequence, and the sample analysis mechanism 3 is communicatively connected to the execution controller 6.

[0041] In this embodiment, the pretreatment mechanism 1 is mainly used to remove debris from the coal gangue and crush and grind the coal gangue; the screening mechanism 2 is arranged downstream of the pretreatment mechanism 1, and is mainly used to screen and grade the coal gangue according to the existence form of pyrite in the coal gangue, and screen the coal gangue with a particle size of less than 60 mm after pretreatment into three particle sizes of 25-60 mm, 6-25 mm and less than 6 mm. The coal gangue with a particle size of less than 6 mm has a higher coal content and a calorific value of more than 2500 kcal, and can be directly sold as raw ore; the sample analysis mechanism 3 is used to analyze the ore with two particle sizes of 25-60 mm and 6-25 mm. The stone sample is analyzed, and the differences in physical, chemical or physicochemical properties between different minerals are used to comprehensively analyze the particle size, yield, weight, composition and other properties of the sample ore, provide sorting process parameters for batch sorting of ore, and send the analysis structure to the execution controller 6 of the intelligent sorting mechanism 4; the intelligent sorting mechanism 4 includes a first sorting part, a second sorting part and an execution controller 6. The execution controller 6 sorts the coal gangue of two particle sizes of 5-60mm and 6-25mm in turn according to the sample analysis results and the collected data of the first sorting part and the second sorting part, and finally obtains clean coal, clean coal gangue and pyrite.

[0042] This sorting system first screens and grades the gangue based on the presence of pyrite in the gangue, then intelligently sorts the graded gangue. This system can intelligently separate clean coal, clean gangue, and pyrite from the gangue, significantly reducing resource and energy consumption. It effectively addresses the challenges of gravity separation and flotation-based processes for directly extracting coal and pyrite from gangue, which suffer from low grade, low sorting efficiency, low processing capacity, high grinding costs, high environmental remediation costs, and difficulty in large-scale production.

[0043] Based on the above technical solution, it is further preferred that the intelligent sorting mechanism 4 further includes a vibrating feeder 7 and a feeding conveyor belt 8, both of which are arranged on the frame body 5, and the feeding conveyor belt 8 is arranged below the vibrating feeder 7. The ore processed by the screening mechanism 2 enters the feeding conveyor belt 8 through the vibrating feeder 7 in sequence.

[0044] In this embodiment, the first sorting part specifically includes a first X-ray identification device 9, a first airflow separator 10 and a clean coal funnel 11. The transmitting end of the first X-ray identification device 9 is vertically pointed at the feeding surface of the feeding conveyor belt 8, and the receiving end of the first X-ray identification device 9 is located directly below the feeding surface of the feeding conveyor belt 8. The signal output end of the first X-ray identification device 9 is connected to the execution controller 6, the first airflow separator 10 is connected to the execution controller 6, and the clean coal funnel 11 is arranged below the first airflow separator 10.

[0045] In this embodiment, the second sorting part specifically includes a second X-ray identification device 12, a second airflow separator 13, a clean coal gangue funnel 14 and a pyrite funnel 15. The second X-ray identification device 12 is arranged on the frame body 5 and is located below the feeding conveyor belt 8. The transmitting end and the receiving end of the second X-ray are arranged opposite to each other and both point to the residual material after sorting by the first sorting part. The signal output end of the second X-ray identification device 12 is connected to the execution controller 6, and the second airflow separator 13 is connected to the execution controller 6. The clean coal gangue funnel 14 and the pyrite funnel 15 are adjacently arranged below the second airflow separator 13.

[0046] The first airflow separator 10 and the second airflow separator 13 are mainly used to inject the falling ore at high speeds at different angles to change the falling curve of the ore, so that the ore falls into the clean coal hopper 11, the pyrite hopper 15 and the clean coal gangue hopper 14 respectively.

[0047] Specifically, the first airflow sorter 10 and the second airflow sorter 13 may respectively include a robotic arm and a movable nozzle, an air pipe and an air jet controller arranged on the robotic arm. The air jet controller adjusts the movable nozzle on the robotic arm according to the signal given by the execution controller 6, and sprays the ore to achieve ore sorting.

[0048] The structure and implementation of the intelligent sorting mechanism 4 in this embodiment can also refer to the intelligent sorting equipment for metal ores.

[0049] This embodiment does not specifically limit the installation positions of the first X-ray identification device 9, the first airflow separator 10, the clean coal hopper 11, the second X-ray identification device 12, the second airflow separator 13, the clean coal gangue hopper 14 and the pyrite hopper 15, and can be adjusted according to actual needs.

[0050] On the basis of the above technical solution, it is further preferred that the first air flow separator 10 is arranged 100-300 mm below the feeding conveyor belt 8, and the second air flow separator 13 is arranged 1200-1400 mm below the feeding conveyor belt 8 and is located below the second X-ray identification device 12.

[0051] On the basis of the above technical solution, it further includes an air supply device 16 , and the first air flow separator 10 and the second air flow separator 13 are both connected to the air supply device 16 .

[0052] Specifically, the air supply device 16 is communicated with the air pipes in the first air flow separator 10 and the second air flow separator 13 respectively.

[0053] In this embodiment, the screening mechanism 2 specifically includes a screening conveyor belt, a first screening belt, a second screening belt and a receiving belt. The second screening belt is arranged below the first screening belt, and the receiving belt is arranged below the second screening belt.

[0054] The first screening belt, the second screening belt and the receiving belt are used to screen the ores into three particle sizes of 25-60mm, 6-25mm and less than 6mm respectively. The specific setting method can refer to the existing technology.

[0055] In this embodiment, the pre-treatment mechanism 1 includes a crushing device and a grinding device, etc., which are mainly used to remove debris from the coal gangue and crush and grind the coal gangue.

[0056] In addition, in order to further reduce dust pollution, in this embodiment, negative pressure dust hoods are provided at the discharge port of the feeding conveyor belt 8, the blowing port of the first air flow classifier 10 and the blowing port of the second air flow classifier 13.

[0057] In addition to the dust prevention method of negative pressure dust hood, you can also use long-distance water curtain and water mist comprehensive dust prevention methods.

[0058] The present invention also provides a method for separating clean coal and pyrite using the most preferred system for separating clean coal and pyrite from coal gangue, as specifically shown in Example 2.

[0059] Example 2

[0060] S1. Remove debris from the coal gangue and perform crushing and grinding pretreatment in sequence;

[0061] S2. Sieving the pre-treated coal gangue with a particle size of less than 60 mm into three particle sizes: 25-60 mm, 6-25 mm, and less than 6 mm;

[0062] S3, taking ore samples of two particle sizes (25-60 mm and 6-25 mm) and performing ore analysis, imaging analysis, and model analysis in the sample analysis unit 3 respectively;

[0063] In this embodiment, the raw ore analysis is to select samples of the coal gangue that needs to be sorted before batch sorting, and use the differences in physical, chemical or physicochemical properties between different minerals to comprehensively analyze the particle size, yield, weight, composition and other properties of the sample ore to provide sorting process parameters for batch sorting of ore.

[0064] The specific method of raw ore analysis is:

[0065] Visual observation standards:

[0066] 1. Coal: black, light in weight, with obvious bright reflection on the cross section.

[0067] 2. Gangue: gray-black, heavy in texture, and non-reflective on the surface.

[0068] In this embodiment, the ore classification standard can be divided into three types according to composition and density:

[0069] (1) Carbonaceous and carbonaceous shale: mainly composed of clay minerals and some carbonaceous materials, with a slightly lighter weight. Carbonaceous shale is a transitional product between coal and gangue;

[0070] (2) Mud shale: mainly composed of clay minerals and trace carbon, heavy in quality;

[0071] (3) Pyritic shale: mainly composed of pyrite, clay minerals and a small amount of carbon, and is heavy.

[0072] Test items: There are two main items, one is sulfur content and the other is coal content.

[0073] Sorting index: sulfur content and content are both set at <1%.

[0074] Specifically, during the raw ore analysis, representative ore samples of the two particle sizes of 25-60 mm and 6-25 mm were divided into four types of ore samples: clean coal, high-sulfur grade, medium-sulfur grade, and low-sulfur grade, based on the distribution of clean coal and pyrite in the gangue, using an ore density detector and visual observation. The four ore samples were then weighed (to determine the yield of each particle size), tested for calorific value (to determine the amount of clean coal and the distribution rate in each particle size), and tested for sulfur and iron content (to determine the grade and distribution rate of sulfur and iron content in each particle size). The data are shown in Table 1 below.

[0075] Table 1 Analysis data of 25-60mm particle size ore samples

[0076]

[0077] As shown in Table 1, the highest low calorific value of clean coal is 5825kcal / kg, and the yield is 4.55%. In order to ensure the desulfurization effect (S grade <1%), the low-sulfur grade and medium-sulfur grade in the ore need to be selected as ore. The comprehensive yield is about 68%, and the comprehensive S grade is about 0.15%. This can achieve the enrichment of clean coal and reduce the impact of S on waste rock, so as to maximize the utilization of value and reduce the subsequent grinding and sorting costs.

[0078] Table 2 Analytical data of 6-25mm particle size ore samples

[0079]

[0080] As shown in Table 2, the highest low calorific value of clean coal is 2245kcal / kg, and the yield is 4.55%. In order to ensure the desulfurization effect (S grade <1%), the low-sulfur grade and medium-sulfur grade in the ore need to be selected as ore, with a comprehensive yield of about 67% and a comprehensive S grade of about 0.1%. This can achieve the enrichment of clean coal and reduce the impact of S on the remaining coal gangue, so as to maximize the utilization of value and reduce the subsequent grinding and sorting costs.

[0081] During imaging analysis, X-ray imaging is performed on the distribution of four ore samples. The penetrability of X-ray ions and the difference in ore density are used to develop images. Ores with common characteristics are selected from the imaging images. Then, multi-angle imaging is performed on each ore sample. About 6-8 imaging images are taken to obtain a multi-angle imaging group for each ore sample.

[0082] Imaging analysis data reveals that clean coal appears light blue-green. High-sulfur samples appear darker and have distinct mineral spots, while medium- and low-sulfur samples appear lighter and lack distinct mineral spots. This further demonstrates that minerals with varying levels of useful components within a sample exhibit distinct differences in their X-ray absorption patterns. Samples of different grades can be clearly distinguished after absorbing a single X-ray, with distinct imaging differences. These imaging differences are a crucial prerequisite for ensuring effective sorting. (See image)

[0083] In this embodiment, the transmitter used in the imaging analysis is an X-ray transmitter and an X-ray imaging recognition receiver (which may be integrated).

[0084] During model analysis, the image groups obtained from the imaging analysis are analyzed. Based on the imaging differences, the image groups of sulfur content and calorific value in the ore samples are integrated into a model. The model is input into the execution controller for recognition training. After the training is completed, batch sorting begins.

[0085] S4. The model analysis results are transmitted to the execution controller 6. First, 25-60 mm is transmitted to the intelligent sorting mechanism 4. In the intelligent sorting mechanism 4, the first X-ray recognition device 9 continuously shoots and identifies the gangue passing through the feeding conveyor belt 8. The captured images are saved and transmitted to the execution controller 6 for analysis and processing. The execution controller 6 identifies the model in the model analysis, that is, the parameters of calorific value (clean coal) and sulfur content <1%, and controls the high-speed air valve of the first air flow separator 10 to blow the gangue at different angles. The blowing air volume is controlled by the execution controller according to the weight of the ore to be sprayed and sorted. The first air flow separator 10 executes the blowing time interval of 1.5 ms to change the falling curve of the gangue. , clean coal and residual material are obtained by sorting; the second X-ray identification device 12 continuously shoots and identifies the residual material, and the captured images are saved and transmitted to the execution controller 6 for analysis and processing. The execution controller 6 identifies according to the model in the model analysis, and controls the second air flow sorter 13 to blow the coal gangue at different angles. The blowing air volume is controlled by the execution controller according to the weight of the ore to be sprayed and sorted. The second air flow sorter 13 executes the blowing time interval of 1.5ms, which is much greater than the free fall speed, and clean coal gangue and pyrite are sorted; then the sample with a particle size of 6-25mm is transported to the intelligent sorting mechanism 4, and the above process is repeated. Finally, clean coal, clean coal gangue and pyrite are obtained, and the purpose of sorting is achieved.

[0086] The sorting data obtained in this embodiment are shown in Table 3 and Table 4.

[0087] Table 3 25-60mm ore sorting data

[0088]

[0089] Table 4 6-25mm particle size ore sorting data

[0090]

[0091] It can be seen from Table 3-4 that when the present invention is used to sort 25-60 mm particle size coal gangue, the clean coal sorting yield is about 2.5%, and the low calorific value is about 5600 kcal / kg. For desulfurization sorting, the yield of ore with a sulfur grade higher than 1% is about 20%, and the S grade is about 4.5%; when the present invention is used to sort 6-25 mm particle size coal gangue, the clean coal yield is about 3%, and the low calorific value is about 2974 kcal / kg. For desulfurization sorting, the yield of ore with a sulfur grade higher than 1% is about 7.6%, and the S grade is about 6%.

[0092] In summary, the sorting system and method of the present invention first screens and grades the gangue according to the existence form of pyrite in the gangue, and then intelligently sorts the classified gangue, effectively solving the problems of low grade, low sorting efficiency, small processing capacity, high grinding cost, high environmental governance cost, and difficulty in large-scale production in the process of directly selecting coal and pyrite from gangue mainly by gravity separation and flotation.

[0093] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A system for separating clean coal and pyrite from coal gangue, characterized in that: It includes a pre-treatment mechanism (1), a screening mechanism (2), a sample analysis mechanism (3) and an intelligent sorting mechanism (4). The intelligent sorting mechanism (4) comprises a frame body (5), a first sorting part, a second sorting part and an execution controller (6), wherein the first sorting part and the second sorting part are sequentially arranged on the frame body (5) from top to bottom, and the execution controller (6) is used to control the first sorting part and the second sorting part to sort the ore; The pretreatment mechanism (1), the screening mechanism (2) and the intelligent sorting mechanism (4) are connected in sequence, and the sample analysis mechanism (3) is communicatively connected with the execution controller (6); The screening mechanism is set downstream of the pretreatment mechanism to screen the pretreated coal gangue with a particle size of less than 60mm into three particle sizes: 25-60mm, 6-25mm and less than 6mm. The coal gangue with a particle size of less than 6mm has a high coal content and a calorific value of more than 2500 kcal, and is directly sold as raw ore. The sample analysis mechanism is used to analyze ore samples of two particle sizes, 25-60mm and 6-25mm, and send the analysis results to the execution controller of the intelligent sorting mechanism; The execution controller sequentially sorts the coal gangue of two particle sizes, 5-60mm and 6-25mm, according to the sample analysis results and the collected data of the first sorting section and the second sorting section, to obtain clean coal, clean coal gangue and pyrite.

2. The system for separating clean coal and pyrite from gangue according to claim 1, characterized in that: The intelligent sorting mechanism (4) further comprises a vibrating feeder (7) and a feeding conveyor belt (8), wherein the vibrating feeder (7) and the feeding conveyor belt (8) are both arranged on the frame body (5), and the feeding conveyor belt (8) is arranged below the vibrating feeder (7).

3. The system for separating clean coal and pyrite from gangue according to claim 2, characterized in that: The first sorting section includes a first X-ray identification device (9), a first airflow separator (10) and a clean coal hopper (11), wherein the transmitting end of the first X-ray identification device (9) is vertically directed to the feeding surface of the feeding conveyor belt (8), the receiving end of the first X-ray identification device (9) is located directly below the feeding surface of the feeding conveyor belt (8), the signal output end of the first X-ray identification device (9) is connected to the execution controller (6), the first airflow separator (10) is connected to the execution controller (6), and the clean coal hopper (11) is arranged below the first airflow separator (10).

4. The system for separating clean coal and pyrite from gangue according to claim 3, characterized in that: The second sorting section includes a second X-ray identification device (12), a second airflow separator (13), a clean gangue hopper (14) and a pyrite hopper (15). The second X-ray identification device (12) is arranged on the frame body (5) and is located below the feeding conveyor belt (8). The transmitting end and the receiving end of the second X-ray are arranged opposite to each other and both point to the residual material after being sorted by the first sorting section. The signal output end of the second X-ray identification device (12) is connected to the execution controller (6). The second airflow separator (13) is connected to the execution controller (6). The clean gangue hopper (14) and the pyrite hopper (15) are adjacently arranged below the second airflow separator (13).

5. The system for separating clean coal and pyrite from gangue according to claim 4, characterized in that: The first air flow separator (10) is arranged 100-300 mm below the feeding conveyor belt (8), and the second air flow separator (13) is arranged 1200-1400 mm below the feeding conveyor belt (8).

6. The system for separating clean coal and pyrite from gangue according to claim 4, characterized in that: It also includes an air supply device (16), and the first air flow separator (10) and the second air flow separator (13) are both connected to the air supply device (16).

7. The system for separating clean coal and pyrite from gangue according to claim 1, characterized in that: The screening mechanism (2) comprises a screening conveyor belt, a first screening belt, a second screening belt and a receiving belt, wherein the second screening belt is arranged below the first screening belt, and the receiving belt is arranged below the second screening belt.

8. A method for separating clean coal and pyrite using the system for separating clean coal and pyrite from coal gangue according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1. Remove debris from the coal gangue and perform crushing and grinding pretreatment in sequence; S2. Sieving the pre-treated coal gangue with a particle size of less than 60 mm into three particle sizes: 25-60 mm, 6-25 mm, and less than 6 mm; S3, taking ore samples of two particle sizes (25-60 mm and 6-25 mm) and conducting raw ore analysis, imaging analysis and model analysis in the sample analysis unit (3); S4, the model analysis results are transmitted to the execution controller (6), and the samples of the two particle sizes of 25-60 mm and 6-25 mm are successively transmitted to the intelligent sorting mechanism (4), and after being sorted by the first sorting part and the second sorting part, clean coal, clean coal gangue and pyrite are obtained.

9. The method for separating clean coal and pyrite according to claim 8, characterized in that: In step S3, during the raw ore analysis, representative ore samples of two particle sizes (25-60 mm and 6-25 mm) are divided into four types of ore samples: clean coal, high-sulfur-containing grade, medium-sulfur-containing grade, and low-sulfur-containing grade, based on the distribution of clean coal and pyrite in the gangue, using an ore density detector and visual observation. The calorific value, sulfur content, and iron content of the four ore samples are then assayed. In step S3, during the imaging analysis, X-ray imaging is performed on the four ore sample distributions, and multi-angle imaging is performed on each ore sample to obtain a multi-angle imaging group for each ore sample; In step S3, during the model analysis, the imaging groups obtained in the imaging analysis are analyzed, and the imaging groups of sulfur content and calorific value in the ore sample are model-integrated based on the imaging differences.

10. The method for separating clean coal and pyrite according to claim 9, characterized in that: In step S4, in the intelligent sorting mechanism (4), the first X-ray recognition device (9) continuously photographs the gangue passing through the feeding conveyor belt (8), and the photographed images are saved and transmitted to the execution controller (6) for analysis and processing. The execution controller (6) controls the air volume of the first air flow separator (10) on the gangue according to the processing results, and sorts clean coal and residual material; the second X-ray recognition device (12) continuously photographs the residual material, and the photographed images are saved and transmitted to the execution controller (6) for analysis and processing. The execution controller (6) controls the air volume of the second air flow separator (13) on the gangue according to the processing results, and sorts clean gangue and pyrite.

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