A control method for a crushing system based on circulating load

Abstract

The present application discloses a control method for a crushing system based on circulating load, including: calculating the control circulating load through the product particle size curve of the crusher in the crushing system and the screening efficiency of the screening equipment, and determining the numerical range of the control circulating load according to the fluctuation of the screening efficiency caused by the ore properties; obtaining the weighing conveying amounts in real time through the belt scales of the feeding belt conveyor, the return belt conveyor, and the final product belt conveyor, and performing balance correction of the ore amount according to the weighing conveying amounts, and calculating the actual circulating load through the conveying amount obtained by weighing after the correction balance; adjusting the discharge opening of the crusher and the feeding amount parameters according to the comparison between the actual circulating load and the control circulating load, and recalculating the actual circulating load until the actual circulating load is within the control range of the control circulating load. The present application indirectly reflects the operating state of the crushing system through the analysis of the circulating load fluctuation, has a high degree of automation, and can greatly reduce the labor intensity of the operators.

Description

Technical Field

[0001] The present invention relates to the technical field of crushing, and specifically, to a control method for a crushing system based on circulating load. Background Art

[0002] The crushing system and the grinding system constitute the ore preparation link of a concentrator. The product quality of the crushing system directly affects the operation and cost of the subsequent grinding system. The crushing system is a key link to achieve "more crushing and less grinding". The crushing system usually consists of medium crushing, fine crushing, screening, and belt conveyors connecting each operation. Medium crushing is usually a cone crusher, and fine crushing is usually a cone crusher or a high-pressure roller mill. In special cases, there is ultra-fine crushing operation. At present, the basic control of the actual production operation of the crushing system in concentrators mainly includes the interlock control of the automatic start and stop of the entire system, the automatic stop interlock control in the accident state of the crushing system, the power control of local cone crushers (for example, the patent application publication number: CN106345600 A), etc. The control methods and strategies based on the entire crushing system have not been involved yet. The main reason is that in the actual production process, production managers and actual operators usually do not analyze, evaluate, and control the indicators and parameters such as the balance, stability, and energy consumption of the entire system. In most cases, once production instability and process parameter deviation occur, resulting in the inability to meet the subsequent production needs, the factory or workshop usually organizes corresponding manpower and material resources to conduct a detailed and systematic process inspection of the crushing system. Through the process inspection, problems are identified, specific reasons are analyzed, and on this basis, control strategies and improvement measures are studied and formulated, and then implemented to adjust to achieve the purpose of solving problems, stabilizing production, and obtaining qualified products.

[0003] The applicant analyzed the current situation of the crushing system, and there are the following prominent problems and disadvantages in terms of control, automation, and intelligence:

[0004] (1) Usually, the particle size of the products of the crushing system changes little, and the particle size of the products is easy to reach. The crushing system usually has a relatively flexible maintenance space, so the control requirements are low, and the demand for improving the automation and intelligence technologies of the crushing system is not strong. For example, in the crushing system, the automation and intelligence levels of jaw crushers, cone crushers, etc. are relatively high, but the intelligence levels of screening equipment, belt conveyors, etc. are relatively low, and the intelligence demand of the entire system is low.

[0005] (2) The current control of the crushing system mostly focuses on the final product particle size. When there are problems with the product particle size, manual means are usually used to adjust the discharge openings of medium and fine crushing equipment and the control parameters of high-pressure roller mills, and the manual operation labor intensity is high.

[0006] (3) Currently, the feed quantity of the screening operation is not detected or controlled. The feed quantity of the screening operation directly affects the screening operation load, screening efficiency, and the quality of the undersize product. At the same time, the oversize material quantity in the screening operation affects the processing capacity of subsequent fine crushing and high-pressure roller mills.

[0007] (4) The current feeding equipment at the front end of the crusher, when the automation level is high, adjusts the feed quantity according to the material level in the upper hopper of the cone crusher to ensure full feeding of the crusher. However, it usually does not pay attention to power, subsequent product quantity, and product particle size, without systematic consideration.

[0008] (5) The current crushing system has no control objectives or control means. Its energy consumption, liner consumption, processing capacity fluctuations, etc. have not been automatically detected or intelligently controlled. Among them, the consumption of crusher liners and the wear and consumption of the roll surface of high-pressure roller mills are the main cost components, which have a greater impact on the benefits of the concentrator.

[0009] The applicant found that the circulating load is an important parameter reflecting the closed-circuit operation of the crushing system. It directly reflects the operating efficiency of crushing equipment and screening equipment, and can indirectly reflect changes in equipment parameters, mainly including a too large discharge opening of the crusher and blocked sieve holes of screening equipment. The circulating load can be used as a characterization parameter to implement intelligent control of the entire crushing system. So far, there is no relevant technology that uses the circulating load to perform intelligent control on the crushing system. Summary of the Invention

[0010] Based on the current situation of crushing system control, the present invention uses intelligent technology and big data analysis to propose an intelligent control method for a crushing system based on process calculation, on-site instrument detection and analysis. This method takes the circulating load as the control objective. The technical solutions adopted in this application are as follows:

[0011] A control method for a crushing system based on circulating load, comprising:

[0012] Step S1, calculate the control circulating load of the crushing system through the product particle size curve of the crusher in the crushing system and the screening efficiency of the screening equipment, and determine the numerical range of the control circulating load according to the screening efficiency fluctuation caused by the ore properties;

[0013] Step S3, during the operation of the crushing system, obtain the weighing and conveying quantity in real time through the feed belt conveyor weigher 4, the return belt conveyor weigher 8, and the final product belt conveyor weigher 12, and perform balance correction of the ore quantity according to the weighing and conveying quantity. After the correction and balance, calculate the actual circulating load through the weighing and conveying quantity;

[0014] Step S4: Adjust the discharge opening parameters of the crusher and the ore feeding amounts of the crushing feeder equipment and the screening feeder equipment based on the comparison between the actual circulating load and the controlled circulating load, and return to Step S3 until the actual circulating load is within the numerical range of the controlled circulating load.

[0015] Optionally, the crusher includes an intermediate crusher and a fine crusher.

[0016] Optionally, the balance correction of the ore amount according to the weighed conveying amount means that:

[0017] Adjust the feeding amount through the fine crushing feeder equipment 9 to achieve that the weighed conveying amount of the return belt conveyor weigher 8 + the weighed conveying amount of the final product belt conveyor weigher 12 = the weighed conveying amount of the ore feeding belt conveyor weigher 4 --- Formula 2.

[0018] Optionally, the correction balance means that the numerical difference between both sides of the equal sign in Formula 2 is within ±5%.

[0019] Optionally, in the three-stage one-closed-circuit process, the calculation formula for its controlled circulating load is as follows:

[0020] C S =(1 - β1 * E) / (β5 * E) * 100; --- Formula 1

[0021] Wherein, C S is the circulating load of the three-stage one-closed-circuit process; E is the screening efficiency; β1 is the percentage of the material content smaller than the screen hole size in the intermediate crushing product; β5 is the percentage of the material content smaller than the screen hole size in the fine crushing product.

[0022] Optionally, after the correction balance, calculate the actual circulating load according to the ratio of the oversize material Q4 to the undersize material Q3. Q3 is the weighed conveying amount of the final product belt conveyor weigher 12, and Q4 is the weighed conveying amount of the return belt conveyor weigher 8.

[0023] Optionally, based on the comparison between the actual circulating load and the controlled circulating load, adjusting the discharge opening parameters of the crusher and the ore feeding amounts of the crushing feeder equipment and the screening feeder equipment includes:

[0024] If the actual circulating load is lower than the lower limit of the controlled circulating load range, first increase the discharge opening of the crusher; in the case where the discharge opening is adjusted to the maximum and the actual circulating load is still lower than the lower limit of the controlled circulating load range, increase the ore feeding amount of the screening equipment until the actual circulating load is within the controlled circulating load range;

[0025] If the actual circulating load is higher than the upper limit of the controlled circulating load range, first adjust the discharge opening of the crusher to a smaller size; in the case where the discharge opening is adjusted to the minimum and the actual circulating load is still higher than the upper limit of the controlled circulating load range, reduce the feed rate of the screening equipment until the actual circulating load is within the controlled circulating load range.

[0026] Optionally, in the crushing system, the mined ore is transported to the ore bin and then fed into the intermediate crusher 2 through the intermediate crushing feeder 1 for crushing. The intermediate crushing product produced by the intermediate crusher 2 is discharged to the feed belt conveyor 3. The feed belt conveyor 3 transports the material and feeds it into the screening equipment 6 for screening. The oversize material enters the oversize return belt conveyor 7 and is fed into the fine crusher 10 through the fine crushing feeder 9 for fine crushing. The fine crushing product produced by the fine crusher 10 and the intermediate crushing product produced by the intermediate crusher 2 are combined and enter the subsequent operation through the feed belt conveyor 3. The feed belt conveyor 3, the screening equipment 6, the oversize return belt conveyor 7 and the fine crusher 10 form a closed circuit, and the undersize material enters the final product belt conveyor 11.

[0027] Optionally, after step S1, there is also step S2, which is to collect the product particle size curve of the crusher during the operation of the crushing system and recalculate to obtain the numerical range of the controlled circulating load in combination with the actual situation of the screening efficiency.

[0028] The present application has the following beneficial effects:

[0029] (1) In the closed-circuit crushing system, the circulating load is used as the control parameter of the crushing system to connect the crushing equipment, screening equipment and their belt conveyors. The operating state of the crushing system is indirectly reflected through the analysis of the circulating load fluctuation, with a high degree of automation and significantly reducing the labor intensity of the operators.

[0030] (2) Through intelligent control, the process inspection work of the crushing system with large workload, human and material consumption is cancelled and replaced. Real-time analysis of the relevant parameters of the crushing system process is achieved, the crushing and screening production loads are reasonably allocated, the crushing and screening efficiencies are greatly improved, and the power consumption is controllable.

[0031] (3) The present invention realizes the intelligent control of the crushing system through the calculation and analysis of the circulating load and in combination with the system detection operation parameters, and finally achieves the system control with the best processing capacity of the crushing system, qualified product particle size, low energy consumption and reasonable lining plate service life.

[0032] (4) The present invention can master the crushability characteristics of the ore through long-term big data analysis and detection, judge the change of the ore properties according to the circulating load situation, thereby reasonably adjusting the system capacity, extending or shortening the operation time of the crushing system, and exerting the maximum production energy efficiency. Description of the Drawings

[0033] Figure 1Schematic diagram of the crushing system according to an embodiment of the present invention.

[0034] Figure 2 Flow chart of the control method for the crushing system based on circulating load according to an embodiment of the present invention. Detailed implementation manners

[0035] The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings. Apparently, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art without creative efforts based on the embodiments of the present invention belong to the scope of protection of the present invention.

[0036] In this embodiment, the control circulating load is obtained through theoretical calculation and actual material detection. In actual production, the weighing conveying amount is obtained through the belt scale of the belt conveyor, and the actual circulating load is calculated. By comparing the actual circulating load with the control circulating load, and then adjusting parameters such as the discharge opening, the feeding amounts of the crushing equipment and the screening equipment, etc., stability is finally achieved. This system realizes the overall control of the crushing system, timely reflects the operating state of the crushing system, realizes intelligent control, can greatly improve the system capacity and operation rate, and at the same time reduces the consumption of main materials such as liners, roll surfaces and sieve plates.

[0037] The crushing system based on circulating load in this embodiment includes an intermediate crushing feeding device 1 (belt feeder or vibrating feeder), an intermediate crushing crusher 2 (cone crusher or other crushers), a feeding belt conveyor 3, a feeding belt conveyor belt scale 4 (electronic belt scale or nuclear scale), a screening feeding device 5 (belt feeder or vibrating feeder), a screening device 6 (circular vibrating screen or linear vibrating screen, etc.), an oversize return belt conveyor 7, a return belt conveyor belt scale 8 (electronic belt scale or nuclear scale), a fine crushing feeding device 9 (belt feeder or vibrating feeder), a fine crushing crusher 10 (cone crusher or high pressure roller mill), a final product belt conveyor 11, and a final product belt conveyor belt scale 12 (electronic belt scale or nuclear scale). It should be noted that the crushing equipment of the crushing system can be a cone crusher, a hammer crusher, a counterattack crusher, a high pressure roller mill and other equipment, and the screening equipment can be a circular vibrating screen, a linear vibrating screen, a banana-shaped vibrating screen, etc.

[0038] The ore mined in the mining area is transported to the ore bin, and then fed into the intermediate crusher 2 through the intermediate crushing feeding equipment 1 for crushing. The intermediate crushing products produced by the intermediate crusher 2 are discharged to the feeding belt conveyor 3. The feeding belt conveyor 3 transports the material into the buffer ore bin before screening, and then is fed into the screening equipment 6 through the screening feeding equipment 5 for screening. The oversize materials enter the oversize return belt conveyor 7 and return to the buffer ore bin before fine crushing operation, and then are fed into the fine crusher 10 through the fine crushing feeding equipment 9 for fine crushing. The fine crushing products produced by the fine crusher 10 and the intermediate crushing products produced by the intermediate crusher 2 are combined and enter the subsequent operation through the feeding belt conveyor 3. The feeding belt conveyor 3, the screening equipment 6, the oversize return belt conveyor 7 and the fine crusher 10 form a closed circuit. The undersize materials enter the final product belt conveyor 11 and are transported to the grinding operation. Belt scales 4, 8 and 12 are respectively installed on the feeding belt conveyor 3, the return belt conveyor 7 and the final product belt conveyor 11 to weigh and obtain the real-time conveying volume, and the real-time circulating load value is obtained through calculation.

[0039] The control method of the crushing system based on the circulating load includes the following steps:

[0040] Step S1, calculate the control circulating load of the crushing system through the product particle size curves of the intermediate crusher 2 and the fine crusher 10 in the crushing system and the screening efficiency of the screening equipment 6, and determine the numerical range of the control circulating load according to the planned production fluctuation conditions (mainly referring to the fluctuation of the screening efficiency caused by the material).

[0041] For example: A certain copper mine adopts a three-stage one-closed-circuit process, and the flow chart is as Figure 2 shown. The calculation formula of its control circulating load is as follows:

[0042] C S = Q5 / Q1 = (1 - β1*E) / (β5*E)*100; --- Formula 1

[0043] Among them, Cs is the control circulating load of the three-stage one-closed-circuit process; Q1 is the intermediate crushing product; Q2 is the screening feed material; Q3 is the undersize material; Q4 is the oversize material; Q5 is the fine crushing product; E is the screening efficiency, usually 80% - 90%; β1 is the percentage of the material content less than the screen hole size in the intermediate crushing product; β5 is the percentage of the material content less than the screen hole size in the fine crushing product.

[0044] A copper ore concentrator uses a three-stage single-closed circuit process for crushing and screening. For intermediate crushing, a Metso standard cone crusher is selected, with the CSS of the intermediate crushing discharge opening being 38 mm; for fine crushing, a Metso short head cone crusher is selected, with the CSS of the fine crushing discharge opening being 16 mm; the controlled particle size of the final screening in the three-stage single-closed circuit is 12 mm. First, according to the particle size curve obtained with the CSS of the intermediate crushing discharge opening being 38 mm from the Metso crusher sample, the content of -12 mm is verified to be 16%; according to the particle size curve obtained with the CSS of the fine crushing discharge opening being 16 mm, the content of -12 mm is verified to be 63%. According to the theoretical values of the particle size fraction content below the screen aperture obtained from the sample, using formula 1, when the screening efficiency E = 80%, the calculated circulating load is 173.02%; when the screening efficiency E = 90%, the calculated circulating load is 150.97%.

[0045] Through the above theoretical calculations, considering the fluctuations in the screening efficiency caused by changes in ore properties and other factors, the controlled circulating load calculated, which is the controlled circulating load for the three-stage single-closed circuit control of a certain copper mine, is 150.97% - 173.02%.

[0046] Step S2: According to the operating conditions of the crushing system and combined with the ore characteristics, conduct particle size detection of the products in each operation section to obtain the product particle size curve, and recalculate the range of the controlled circulating load value in combination with the actual situation of the screening efficiency. The more practical controlled circulating load obtained by carrying out step S2 can be used to verify the controlled circulating load in step S1 to ensure the accuracy of the controlled circulating load, but this is not mandatory.

[0047] Step S3: During the production process, obtain the weighing and conveying amounts in real time through the belt scale 4 on the feed belt conveyor 3, the belt scale 8 on the oversize return belt conveyor 7, and the belt scale 12 on the final product belt conveyor 11, and conduct balance correction of the ore quantity based on the weighing and conveying amounts. On the basis of the corrected balance, calculate the actual circulating load through the weighed conveying amount;

[0048] Conduct balance correction of the ore quantity according to the weighing and conveying amounts. For example, for a certain copper mine with a three-stage single-closed circuit as exemplified above, its screening feed Q2 = Q3 + Q4. From a theoretical perspective, balance can be achieved after production stabilizes. Correspondingly:

[0049] The weighing and conveying amount of the belt scale 8 on the oversize return belt conveyor 7 + the weighing and conveying amount of the belt scale 12 on the final product belt conveyor 11 = the weighing and conveying amount of the belt scale 4 on the feed belt conveyor 3. ---- Formula 2

[0050] If balance cannot be achieved, the fine feed amount can be finely adjusted through the fine crushing feeding device 9 under the buffer ore bin to achieve balance, and the balance requirement can be within ±5% of the numerical difference between the two sides of formula 2.

[0051] Based on the corrected balance, for the three-stage and one-closed-circuit process, according to C S = Q5 / Q1 to calculate the actual circulating load. After the corrected balance, Q1 = Q3, Q4 = Q5, Q3 is the weighing and conveying capacity of the belt scale 12 on the final product belt conveyor 11, and Q4 is the weighing and conveying capacity of the belt scale 8 on the oversize return belt conveyor 7.

[0052] Step S4: Compare and analyze the actual circulating load with the controlled circulating load, and adjust parameters such as the discharge opening of the intermediate crusher 2, the discharge opening of the fine crusher 10, and the ore feeding amounts of the intermediate feeding equipment 1, the screening feeding equipment 5, and the fine feeding equipment 9. Then return to step S3 to calculate the actual circulating load and the controlled circulating load again for comparison and analysis. By repeating this cycle, finally, the actual circulating load is within the control range of the controlled circulating load, achieving stable and efficient operation of the crushing system.

[0053] Specifically, expert analysis and fuzzy control can be used to formulate the control logic, and parameter adjustment is carried out according to the control logic, including:

[0054] (1) Compile the expert experience into fuzzy rules, where

[0055] When comparing the actual circulating load with the controlled circulating load, the following situations (not all situations) may occur:

[0056] Input: The actual circulating load is lower than the lower limit of the controlled circulating load range;

[0057] The actual circulating load is higher than the upper limit of the controlled circulating load range;

[0058] Output: When the actual circulating load is lower than the lower limit of the controlled circulating load range, the possible reasons for analysis are: The discharge opening of the crusher is too small, resulting in finer particle size; The ore property becomes softer, resulting in finer particle size.

[0059] Based on the above analysis, determine the control logic and strategy: The first measure is to preferentially adjust the discharge opening of the crusher through intelligent control. Since the on-site circulating load is low, the discharge opening should be enlarged; When this adjustment reaches the limit and the circulating load is still low, start the second measure, adjust the ore feeding amount of the screening equipment. Since the circulating load is low, the ore feeding amount should be increased until the actual circulating load is within the controlled circulating load range.

[0060] When the actual circulating load is higher than the upper limit of the controlled circulating load range, the possible reasons for analysis are: The discharge opening of the crusher becomes larger due to wear, resulting in coarser particle size; The ore property becomes harder, resulting in coarser particle size; The screen holes are blocked, resulting in coarser particle size.

[0061] Determine the control logic and strategy based on the above analysis: First measure, preferentially adjust the discharge opening of the crusher by intelligent control. Since the on-site circulating load is high, the discharge opening should be adjusted smaller; when it cannot be adjusted further; if the circulating load is still high, start the second measure, adjust the feed rate of the screening equipment. Since the circulating load is high, the feed rate should be reduced until the actual circulating load is within the controlled circulating load range.

[0062] (2) Fuzzify the actual circulating load (or the comparison result between the actual circulating load and the controlled circulating load);

[0063] (3) Use the fuzzified actual circulating load (or the comparison result between the fuzzified actual circulating load and the controlled circulating load) as the input of the fuzzy rule, so as to obtain the output quantity according to the fuzzy rule.

[0064] In summary, this application combines the analysis of the ore properties of the project and the parameters of the equipment to form a complete set of expert control logic, and uses the fuzzy control algorithm for determination, ultimately realizing the stable control of the actual circulating load within the controlled circulating load range. It should be noted that the above fuzzy control algorithm is only an example, and this application does not limit the use of other algorithms for determination and output of parameter adjustment amounts. For example, the degree to which the actual circulating load is lower than the lower limit of the controlled circulating load range can also be established corresponding to the step size of increasing the discharge opening and the step size of increasing the feed rate, and the degree to which the actual circulating load is higher than the upper limit of the controlled circulating load range can be established corresponding to the step size of reducing the discharge opening and the step size of reducing the feed rate, and the actual circulating load is adjusted step by step to be within the control range of the controlled circulating load.

[0065] Of course, the present invention can also have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and deformations according to the present invention, but these corresponding changes and deformations all fall within the protection scope of the claims of the present invention.

Claims

1. A control method for a crushing system based on circulating load, characterized in that, Including: Step S1: Calculate the control circulating load of the crushing system through the product size curve of the crusher in the crushing system and the screening efficiency of the screening equipment, and determine the numerical range of the control circulating load according to the screening efficiency fluctuation caused by the ore properties; Step S3: During the operation of the crushing system, real-time obtain the weighing and conveying capacity through the feed belt conveyor weigher (4), the return belt conveyor weigher (8), and the final product belt conveyor weigher (12), and perform ore quantity balance correction according to the weighing and conveying capacity. After the correction is balanced, calculate the actual circulating load through the weighing and conveying capacity; Step S4: According to the comparison between the actual circulating load and the control circulating load, adjust the discharge opening parameters of the crusher, and the ore feeding quantity parameters of the crushing feeding equipment and the screening feeding equipment, and return to Step S3 until the actual circulating load is within the numerical range of the control circulating load; According to the comparison between the actual circulating load and the control circulating load, adjust the discharge opening parameters of the crusher, and the ore feeding quantity parameters of the crushing feeding equipment and the screening feeding equipment, including: If the actual circulating load is lower than the lower limit of the control circulating load range, first increase the discharge opening of the crusher; when the discharge opening is adjusted to the maximum and the actual circulating load is still lower than the lower limit of the control circulating load range, increase the ore feeding quantity of the screening equipment until the actual circulating load is within the control circulating load range; If the actual circulating load is higher than the upper limit of the control circulating load range, first decrease the discharge opening of the crusher; when the discharge opening is adjusted to the minimum and the actual circulating load is still higher than the upper limit of the control circulating load range, decrease the ore feeding quantity of the screening equipment until the actual circulating load is within the control circulating load range.

2. The control method of the crushing system based on the circulating load according to claim 1, characterized in that The crusher includes an intermediate crusher and a fine crusher.

3. The control method of the crushing system based on the circulating load according to claim 2, characterized in that The ore quantity balance correction according to the weighing and conveying capacity means: Adjust the feeding quantity through the fine crushing feeding equipment (9) to achieve the weighing and conveying capacity of the return belt conveyor weigher (8) + the weighing and conveying capacity of the final product belt conveyor weigher (12) = the weighing and conveying capacity of the feed belt conveyor weigher (4) - Formula 2.

4. The control method of the crushing system based on the circulating load according to claim 3, wherein The correction balance means that the numerical difference between both sides of the equal sign in Formula 2 is within ±5%.

5. The control method of the crushing system based on the circulating load according to claim 2, characterized in that In the three-stage one-closed circuit process, the calculation formula of its control circulating load is as follows: C S = (1 - β1 * E) / (β5 * E) * 100; --- Equation 1 Among them, C S is the circulating load of the three-stage and one-closed-circuit process; E is the screening efficiency; β1 is the percentage of materials smaller than the screen hole size in the medium-crushed product; β5 is the percentage of materials smaller than the screen hole size in the fine-crushed product.

6. The control method of the crushing system based on the circulating load according to claim 1, wherein After the correction is balanced, calculate the actual circulating load according to the calculation of the oversize material Q4 / undersize material Q3. Q3 is the weighing and conveying capacity of the final product belt conveyor weigher (12), and Q4 is the weighing and conveying capacity of the return belt conveyor weigher (8).

7. The control method of the crushing system based on the circulating load according to claim 2, characterized in that, In the said crushing system, the mined ore is conveyed to the ore bin and then fed into the medium crusher (2) through the medium crushing feeder equipment (1) for crushing. The medium crushing products produced by the medium crusher (2) are discharged to the ore feeding belt conveyor (3). The ore feeding belt conveyor (3) conveys the materials and feeds them into the screening equipment (6) for screening. The oversize materials enter the oversize return belt conveyor (7) and are fed into the fine crusher (10) through the fine crushing feeder equipment (9) for fine crushing. The fine crushing products produced by the fine crusher (10) and the medium crushing products produced by the medium crusher (2) are combined and enter the subsequent operations through the ore feeding belt conveyor (3). The ore feeding belt conveyor (3), the screening equipment (6), the oversize return belt conveyor (7) and the fine crusher (10) form a closed circuit, and the undersize materials enter the final product belt conveyor (11).

8. The control method of the crushing system based on the circulating load according to claim 1, wherein, After step S1, there is also step S2, which is to collect the product particle size curve of the crusher during the operation of the crushing system and recalculate to obtain the control circulating load numerical range in combination with the actual screening efficiency situation.

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