Control method for preventing particle size segregation in large-scale semi-autogenous grinding feeding

Abstract

The invention belongs to the technical field of mineral processing, and provides a control method for preventing particle size segregation of large-scale semi-autogenous grinding feeding, which comprises the following steps of: through a technical path of optimizing a stock bin structure in combination with multi-dimensional monitoring and intelligent closed-loop control, arranging symmetrical feed openings in the center and the periphery of a stock bin, and carrying out dynamic material level monitoring by utilizing a radar material level meter; a frequency converter is configured for speed regulation control of an ore collecting belt below each feed opening, and the speed of the belt is regulated according to data such as the material level height, the ore feeding amount and the granularity deviation based on a PID algorithm, so that closed-loop control is formed. The method solves the problems that in the prior art, particle size segregation is serious, feeding is uneven, and dependence on manual intervention is high, particle size homogenization and stabilization of semi-autogenous grinding feeding are achieved, the operation efficiency and production safety of semi-autogenous grinding are improved, manual intervention is reduced, the production cost is reduced, and the production efficiency and economic benefits are effectively improved.

Description

Technical Field

[0001] This invention belongs to the field of mineral processing technology and relates to the feeding control of large-scale semi-autogenous grinding equipment, specifically a control method for preventing particle size segregation in the feeding of large-scale semi-autogenous grinding equipment. Background Technology

[0002] The feed particle size range for large-scale semi-autogenous grinding mills is typically 100-300mm. When the ore from the blasting at the stope is transported to the silo via the feed conveyor belt, a typical "particle size segregation cone" forms due to gravity separation: The central region contains fine particles (<150mm), which, due to their high drop height, have low inertia and a small angle of repose, resulting in a fine, low-porosity accumulation; the peripheral region contains coarse particles (>200mm), which roll towards the edge of the pile due to inertia, forming a high-porosity coarse particle ring. This natural segregation leads to an initial feed particle size standard deviation of ±40mm under traditional single-center or multi-port random feeding modes, far exceeding the ideal feed uniformity requirement for semi-autogenous grinding mills (standard deviation ≤ ±15mm). Existing technologies have the following significant problems: 1. Severe particle size segregation: Particle size segregation formed by natural accumulation results in large differences in ore particle size at different feed ports, making it difficult to ensure the uniformity of feed particle size.

[0003] 2. High dependence on manual intervention: It requires manual observation or instrument detection of the particle size at each feed port, followed by manual intervention and adjustment. This method is highly random and cannot control the output and particle size distribution in real time and accurately, resulting in inconsistent ore size and unstable semi-autogenous grinding power.

[0004] 3. Difficulty in maintaining the shape of the stockpile: The stockpile in the silo cannot maintain an ideal cone shape. After the material arrives at the mine, large pieces of ore will enter the low-lying areas, further aggravating particle size segregation.

[0005] 4. Impact on production efficiency and equipment safety: Uneven feeding, especially when the particle size is coarse, will cause a sharp increase in the power of the semi-autogenous grinding mill, requiring a reduction in the processing capacity and affecting output; if not handled in time, it may even cause bloating, which will damage the equipment and increase the consumption of steel balls, thus increasing production costs.

[0006] Currently, the closest existing technology literature includes: 1. Patent document: "A feeding system for a semi-autogenous mill". This patent proposes a conventional configuration for a feeding system for a semi-autogenous mill, but does not involve the optimization of the silo structure and the systematic control of particle size segregation.

[0007] 2. Journal article: "Research on the influence of feed particle size distribution on grinding efficiency in semi-autogenous grinding process", which analyzes the influence of feed particle size segregation on the grinding efficiency of semi-autogenous grinding, but does not propose specific control methods. Summary of the Invention

[0008] The purpose of this invention is to provide a control method for preventing particle size segregation in large-scale semi-autogenous grinding feed. By optimizing the silo structure, configuring an intelligent control system, and implementing a reasonable process flow, this method solves the problems of severe particle size segregation, uneven feeding, and strong reliance on manual intervention in existing technologies. It achieves uniform and stable particle size in semi-autogenous grinding feed, improves the operating efficiency and production safety of the semi-autogenous grinding, and reduces production costs.

[0009] The technical solution adopted by the present invention to achieve the above objectives is as follows: A method for controlling particle size segregation in large-scale semi-autogenous grinding feed includes: 1. Setting of material discharge port in hopper; Four to seven discharge ports are set at the bottom of the silo, with one discharge port at the center of the bottom of the silo and three to six discharge ports evenly and symmetrically distributed around the perimeter. 2. Installation and control of ore-collecting conveyor belts; A collection belt is installed below each feed inlet. Each collection belt is independently equipped with a drive wheel motor, and the motors are all connected to frequency converters. The belt speed of the collection belt is linearly related to the output amount. By adjusting the output frequency of the frequency converter, the motor speed is changed, thereby controlling the belt speed and achieving precise adjustment of the output amount. 3. Install material level monitoring equipment to determine the shape of the material pile based on the material level height at the discharge port, and ensure that the material pile maintains a cone shape with a high center and low perimeter. 4. Install a belt scale and an online particle size analyzer on the main feed belt of the semi-autogenous mill. Adjust the belt speed of the collecting belt and the discharge rate of the feed port according to the feed rate and particle size distribution data to control the feed rate and ore particle size distribution.

[0010] Furthermore, the size of the discharge port is designed according to the silo volume and feed rate to ensure that the ore can be discharged smoothly and to avoid the impact of an excessively large or small discharge port on the particle size distribution.

[0011] Furthermore, the inverter model is selected based on the belt load and speed range.

[0012] Furthermore, the material level monitoring device uses a radar level gauge, which is installed at the top of each discharge port. The radar level gauge has a monitoring range of 0-50m and an accuracy of ±0.1m. It can measure the material level height directly above the discharge port in real time. The radar level gauge transmits data to the centralized control system via a 4-20mA signal or Modbus protocol.

[0013] Furthermore, the centralized control system includes an industrial computer, a data acquisition module, a control module, and a human-machine interface. The centralized control system stores material level, belt speed, and feed rate data in a real-time database and supports historical trend queries and fault alarm functions. The data acquisition module collects data including real-time uploading of material level heights at each discharge port by radar level gauges, detection of total feed rate of the main belt by belt scales, and feedback of ore particle size distribution by online particle size analysis devices.

[0014] Furthermore, the method for controlling the material level at the surrounding discharge port includes: Peripheral material level deviation Δh i =Maximum height of material level at surrounding feed inlets h max -Minimum height h of material at the surrounding discharge port min When Δh i When the depth is >0.5m, increase the frequency of the conveyor belt at the high-level feed inlet and decrease the frequency of the conveyor belt at the low-level feed inlet, adjusting the amount by Δf. i Perform material level difference correction; The adjustment amount Δf i The formula for calculating Δf is: i =K p *Δh i +K i ∫Δh i dt+K d (dΔh) i / dt) Among them, K p K i K d The PID parameters are optimized through on-site debugging. After receiving the frequency adjustment command, the frequency converter completes the speed adjustment within 500ms to achieve the balance of the surrounding material levels. When h min When the material level is less than 0.5 meters, the conveyor belt will stop operating and an alarm will be triggered to prevent the material from hitting the feed nozzle when the material level is too low.

[0015] Furthermore, the method for controlling the difference between the central material level and the surrounding material level includes: The difference between the center material level and the surrounding material level Δh0 = center material level height h1 - maximum height of the surrounding material outlet h max Keep Δh0 > L0 * 0.58, where L0 is the horizontal distance from the peripheral discharge port to the center discharge port; When Δh0 < L0 * 0.58, the frequency adjustment amount Δf of the surrounding feed inlet belt is increased as a whole. i This increases the discharge speed of the surrounding discharge ports.

[0016] The adjustment amount Δf i The formula for calculating Δf is:i =K p *Δh0 +K i ∫Δh0dt+K d (dΔh0 / dt) Among them, K p K i K d The PID parameters are optimized through on-site debugging. After receiving the frequency adjustment command, the frequency converter completes the speed adjustment within 500ms, thereby adjusting the surrounding material level.

[0017] Further methods for controlling feed rate deviation include: Feed rate deviation ΔQ = feed rate setpoint Q 设定值 - Actual ore feed rate Q total Control algorithm: Based on PID (Proportional-Integral-Derivative), the overall frequency adjustment Δf of each ore-collecting conveyor belt is calculated according to the feed rate deviation. i ; The adjustment amount Δf i The formula for calculating Δf is: i =K p *ΔQ +K i ∫ΔQdt+K d (dΔQ / dt) Among them, K p K i K d The PID parameters are optimized through on-site debugging. After receiving the frequency adjustment command, the frequency converter completes the speed adjustment within 500ms, thereby achieving dynamic balance of the output.

[0018] Furthermore, methods for controlling the particle size deviation of semi-autogenous grinding feed include: Particle size deviation ΔD = Semi-autogenous grinding feed particle size D(x) - Historical average feed particle size D0. Control algorithm: Based on PID (Proportional-Integral-Derivative) control algorithm, the frequency adjustment Δf of each ore collection belt is calculated according to the particle size deviation. i ; The adjustment amount Δf i The formula for calculating Δf is: i =K p *ΔD +K i ∫ΔDdt+K d (dΔD / dt) Among them, K p K i K d The PID parameters are optimized through on-site debugging. After receiving the frequency adjustment command, the frequency converter completes the speed adjustment within 500ms, thereby achieving dynamic balance of the feed particle size.

[0019] The advantages of this invention over the prior art are: (a) Effectively suppressing particle size segregation By optimizing the layout of the feed hopper outlets and adopting an adaptive control system, the material pile within the hopper maintains an ideal conical shape, higher in the center and lower around the edges with a uniform decrease in height. This ensures relatively stable particle size distribution at the central and peripheral feed outlets. Adjusting the discharge rate at both outlets further enhances the uniformity of the feed particle size distribution. Practical application testing shows that the standard deviation of the feed particle size is reduced by approximately 3% compared to existing technologies, effectively improving the uniformity of the semi-autogenous mill feed.

[0020] (ii) Improve the operational stability of semi-autogenous grinding Uniform feed particle size and stable output significantly reduce the power fluctuation range of the semi-autogenous mill. Statistics show that the power fluctuation amplitude of the semi-autogenous mill is significantly reduced, especially the number of high-power cycles, which can be reduced by about 50%. This avoids the risk of a sharp increase in power and bloating caused by coarse particle size, improves the operational stability and safety of the semi-autogenous mill, and reduces equipment downtime due to malfunctions.

[0021] (iii) Improve production efficiency and reduce costs Due to improved feed uniformity, the semi-autogenous mill can operate under stable conditions, maintaining a high throughput and avoiding the reduction in throughput caused by particle size segregation, thus improving production efficiency. At the same time, stable operating conditions reduce steel ball consumption per unit.

[0022] (iv) Achieve automated control and reduce manual intervention. This invention achieves automated control of the feeding process through a centralized control system and various detection devices, eliminating the need for manual observation and adjustment of the particle size at the discharge port in real time. This reduces manual intervention, lowers the labor intensity of operators, and improves the level of intelligence in the production process. Attached Figure Description

[0023] Figure 1 This is a front view of the silo configuration according to an embodiment of the present invention; Figure 2 This is a left view of the silo configuration according to an embodiment of the present invention; Figure 3 This is a top view of the silo configuration according to an embodiment of the present invention; The diagram shows: 1. Radar level gauge #1 (center feed port level gauge); 2. Radar level gauge #2; 3. Radar level gauge #3; 4. Radar level gauge #4; 5. Radar level gauge #5; 6. Radar level gauge #6; 7. Radar level gauge #7; 8. Stockpile; 9. Feed belt to silo; 10. Online particle size analyzer; 11. Feed port #1; 12. Feed port #2; 13. Feed port #3; 14. Feed port #4; 15. Feed port #5; 16. Feed port #6; 17. Feed port #7; 18. Ore collection belt #1; 19. Ore collection belt #2; 20. Ore collection belt #3; 21. Ore collection belt #4; 22. Ore collection belt #5; 23. Ore collection belt #6; 24. Ore collection belt #7. 25. Main conveyor belt for collecting ore; 26. Electronic belt scale. Detailed Implementation

[0024] The technical solution of the present invention will be described below with reference to the accompanying drawings and preferred embodiments. It should be understood that the preferred embodiments described herein are only for illustration and explanation of the present invention and are not intended to limit the present invention. Example

[0025] Yuanjiacun Iron Mine adopts the SAB grinding process. The 1400-0mm ore mined from the open-pit mine is transported to the coarse crushing station by dump trucks. After being crushed by a 63”-89” or 63”-114” gyratory crusher, 200-0mm (P80=150mm) ore is obtained and then transported to the raw ore bin of the concentrator by belt conveyor.

[0026] Parameters of raw ore silos and equipment in the concentrator: The raw ore silo has a single-series volume of 12,500 m³, a storage capacity of 20,551 t, a storage time of 21.5 hours, a single-series semi-autogenous mill feed rate of 927 t / h, and uses a belt conveyor for discharge with a discharge port size of 1400×3000.

[0027] 2. The semi-autogenous grinding circuit is equipped with three Φ34'×18' wet semi-autogenous grinding mills, each with an installed power of 2×5500kW. The ore discharged from the semi-autogenous grinding mills is classified by a linear screen, and the ore with a thickness of +12.7mm on the screen is returned to the semi-autogenous grinding feed belt conveyor via a return belt conveyor.

[0028] The implementation of the method of the present invention, such as Figure 1-3 As shown, it includes: 1. Configuration of feed hopper discharge ports: Seven discharge ports are set at the bottom of the feed hopper, including one discharge port 1#11 at the center of the bottom of the feed hopper, and six discharge ports 2#12, 3#13, 4#14, 5#15, 6#16, and 7#17 evenly and symmetrically distributed around the perimeter. The size of the discharge ports is designed according to the feed hopper volume and feed rate to ensure that the ore can be discharged smoothly and to avoid the impact of excessively large or small discharge ports on particle size distribution. In this embodiment, the discharge port size is 1400mm×3000mm. 2. Installation and control of ore-collecting conveyor belts; A collection belt is installed below each discharge port, namely Collection Belt 1# 18, Collection Belt 2# 19, Collection Belt 3# 20, Collection Belt 4# 21, Collection Belt 5# 22, Collection Belt 6# 23, and Collection Belt 7# 24. Each collection belt is independently equipped with a drive wheel motor, and the motors are all connected to frequency converters. The frequency converter model is selected according to the belt load and speed range. In this embodiment, an ABB ACS880 series frequency converter is used. The belt speed of the collection belt is linearly related to the output amount. By adjusting the output frequency of the frequency converter, the belt speed is controlled with an accuracy of ±0.1Hz within the range of 0-50Hz, thereby accurately adjusting the output amount.

[0029] 3. Install material level monitoring equipment. Siemens radar level gauges are selected for the material level monitoring equipment. Radar level gauges are installed at the top of each discharge port, namely Radar Level Gauge 1 (center discharge port level gauge), Radar Level Gauge 2, Radar Level Gauge 3, Radar Level Gauge 4, Radar Level Gauge 5, Radar Level Gauge 6, and Radar Level Gauge 7. The radar level gauges have a monitoring range of 0-50m and an accuracy of ±0.1m. They can measure the material level height directly above the discharge port in real time. The radar level gauges transmit data to the centralized control system via 4-20mA signal or Modbus protocol. The material pile shape is determined based on the material level height at the discharge port to ensure that the raw material pile 8 conveyed by the feed belt 9 of the silo maintains a conical shape with a high center and low perimeter.

[0030] Specific methods for controlling the material level at the surrounding discharge ports include: Peripheral material level deviation Δh i =Maximum height of material level at surrounding feed inlets h max -Minimum height h of material at the surrounding discharge port min When Δh i When the depth is >0.5m, increase the frequency of the conveyor belt at the high-level feed inlet and decrease the frequency of the conveyor belt at the low-level feed inlet, adjusting the amount by Δf. i Perform material level difference correction; Adjustment amount Δf i The formula for calculating Δf is: i =K p *Δhi +K i ∫Δh i dt+K d (dΔh) i / dt) Among them, K p K i K d The PID parameters are optimized through on-site debugging. After receiving the frequency adjustment command, the frequency converter completes the speed adjustment within 500ms to achieve the balance of the surrounding material levels; when h min When the material level is less than 0.5 meters, the conveyor belt will stop operating and an alarm will be triggered to prevent the material from hitting the feed nozzle when the material level is too low.

[0031] Methods for controlling the difference between the center material level and the surrounding material level include: The difference between the center material level and the surrounding material level Δh0 = center material level height h1 - maximum height of the surrounding material outlet h max Keep Δh0 > L0 * 0.58, where L0 is the horizontal distance from the peripheral discharge port to the center discharge port; When Δh0 < L0 * 0.58, the frequency adjustment amount Δf of the surrounding feed inlet belt is increased as a whole. i This increases the discharge speed of the surrounding discharge ports.

[0032] The adjustment amount Δf i The formula for calculating Δf is: i =K p *Δh0 +K i ∫Δh0dt+K d (dΔh0 / dt) Among them, K p K i K d The PID parameters are optimized through on-site debugging. After receiving the frequency adjustment command, the frequency converter completes the speed adjustment within 500ms, thereby adjusting the surrounding material level.

[0033] In this embodiment, when the system is running, the height of the material level directly above each discharge port is measured in real time. If the difference between the maximum and minimum height of the material level at the surrounding discharge ports exceeds 0.5 meters, or the difference between the central material level and the surrounding material level exceeds 0.58 times the horizontal distance from the surrounding discharge ports to the central discharge port, a frequency conversion adjustment command is immediately triggered.

[0034] 4. A belt scale 26 and an online particle size analyzer 10 are installed on the main feed belt 25 of the semi-autogenous mill. Based on the feed rate and particle size distribution data, the belt speed of the collecting belt and the discharge rate of the discharge port are adjusted to control the feed rate and ore particle size distribution.

[0035] Specific methods for controlling feed rate deviations include: Feed rate deviation ΔQ = feed rate setpoint Q 设定值 - Actual ore feed rate Q total Control algorithm: Based on PID (Proportional-Integral-Derivative), the overall frequency adjustment Δf of each ore-collecting conveyor belt is calculated according to the feed rate deviation. i ; Adjustment amount Δf i The formula for calculating Δf is: i =K p *ΔQ +K i ∫ΔQdt+K d (dΔQ / dt) Among them, K p K i K d The PID parameters are optimized through on-site debugging. After receiving the frequency adjustment command, the frequency converter completes the speed adjustment within 500ms, achieving dynamic balance of the output.

[0036] Methods for controlling particle size deviation in semi-autogenous grinding feed include: Particle size deviation ΔD = Semi-autogenous grinding feed particle size D(x) - Historical average feed particle size D0. Control algorithm: Based on PID (Proportional-Integral-Derivative) control algorithm, the frequency adjustment Δf of each ore collection belt is calculated according to the particle size deviation. i ; Adjustment amount Δf i The formula for calculating Δf is: i =K p *ΔD +K i ∫ΔDdt+K d (dΔD / dt) Among them, K p K i K d The PID parameters are optimized through on-site debugging. After receiving the frequency adjustment command, the frequency converter completes the speed adjustment within 500ms, achieving dynamic balance of the feed particle size.

[0037] In this embodiment, when the belt scale 26 detects a deviation ΔQ between the feed amount Q_total and the set value, or when the online particle size analysis device analyzes a deviation ΔD between the feed particle size D(x) and the historical average particle size D0, the centralized control system calculates the frequency adjustment amount Δfi of each ore collection belt based on the PID control algorithm and sends the instruction to the frequency converter. The frequency converter completes the speed adjustment within 500ms, realizing the dynamic balance between the output amount and particle size distribution. The centralized control system includes an industrial computer, a data acquisition module, a control module, and a human-machine interface. The centralized control system stores data on material level, belt speed, and feed rate in a real-time database and supports historical trend queries and fault alarm functions. The data acquisition module collects data including real-time uploading of material level height at each discharge port by radar level gauges, detection of total feed rate of the main belt by belt scales, and feedback of ore particle size distribution by online particle size analysis devices.

[0038] The method of this invention adopts the technical path of "silo structure optimization + multi-dimensional monitoring + intelligent closed-loop control", and adopts a symmetrical discharge port layout of "1 center + 3-6 periphery" to form a discharge network covering the entire area of ​​the silo. Through multi-area coordinated discharge, different particle sizes of ore are forcibly mixed.

[0039] The method of this invention is based on real-time monitoring of the material level at each discharge port using radar level gauges. Through the PID closed-loop algorithm of the centralized control system, the belt speed of the ore collection conveyor is dynamically adjusted to ensure that the cone shape of the material pile is maintained, with the middle being higher and the surrounding area lower.

[0040] The method of this invention achieves dual target control of total quantity control and morphological maintenance by real-time monitoring of the deviation between the feed rate and the set feed rate, and fine-tuning the belt speed of the ore collection conveyor according to the material level deviation.

[0041] The method of this invention integrates material level detection, online particle size analysis, belt electronic scale metering and frequency converter adjustment, forming a fully automated closed loop of detection, calculation and adjustment. It requires no manual intervention and achieves a control accuracy of ±3% of feed fluctuation, which is significantly better than the ±10% fluctuation level of traditional manual adjustment.

[0042] After the method of this invention was put into use, practical application tests showed that the standard deviation of the feed particle size was reduced from ±20mm in the existing technology to ±10mm, a reduction of about 10%, effectively improving the uniformity of the semi-autogenous mill feed. The power fluctuation range of the semi-autogenous mill was significantly reduced, especially the number of high-power cycles, which was reduced by about 50%. This avoided the risk of a sharp increase in power and bloating caused by coarse particle size, improving the operational stability and safety of the semi-autogenous mill. The semi-autogenous mill throughput increased by 24t / h, and the steel ball consumption was reduced by 0.1kg / t of feed compared to the existing technology, significantly reducing production costs. Simultaneously, the feeding process was automated, eliminating the need for real-time manual observation and adjustment of the particle size at the feed inlet, reducing the labor intensity of operators and improving the level of intelligence in the production process.

[0043] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for controlling particle size segregation in large-scale semi-autogenous grinding feed, characterized in that: include: (1) Setting of material discharge port in silo; Four to seven discharge ports are set at the bottom of the silo, with one discharge port at the center of the bottom of the silo and three to six discharge ports evenly and symmetrically distributed around the perimeter. (2) Setting and control of ore-collecting conveyor belts; A collection belt is installed below each feed inlet. Each collection belt is independently equipped with a drive wheel motor, and the motors are all connected to frequency converters. The belt speed of the collection belt is linearly related to the output amount. By adjusting the output frequency of the frequency converter, the motor speed is changed, thereby controlling the belt speed and achieving precise adjustment of the output amount. (3) Set up material level monitoring equipment to determine the shape of the material pile based on the material level height at the discharge port, and ensure that the material pile maintains a cone shape with a high center and low sides; (4) Install a belt scale and an online particle size analysis device on the main feed belt of the semi-autogenous mill. Adjust the belt speed of the collecting belt and the discharge rate of the feed port according to the feed rate and particle size composition data to achieve control of the feed rate and ore particle size distribution.

2. The control method for preventing particle size segregation in large-scale semi-autogenous grinding feed according to claim 1, characterized in that: The size of the discharge port is designed according to the silo volume and feed rate to ensure that the ore can be discharged smoothly and to avoid the impact of an excessively large or small discharge port on the particle size distribution.

3. The method for controlling particle size segregation in a large-scale semi-autogenous grinding feed according to claim 1, characterized in that: The inverter model is selected based on the belt load and speed range.

4. The method for controlling particle size segregation in a large-scale semi-autogenous grinding feed according to claim 1, characterized in that: The material level monitoring equipment uses radar level gauges, which are installed at the top of each discharge port. The radar level gauges have a monitoring range of 0-50m and an accuracy of ±0.1m. They can measure the material level height directly above the discharge port in real time. The radar level gauges transmit data to the centralized control system via 4-20mA signals or Modbus protocol.

5. The method for controlling particle size segregation in a large-scale semi-autogenous grinding feed according to claim 4, characterized in that: The centralized control system includes an industrial computer, a data acquisition module, a control module, and a human-machine interface. The centralized control system stores material level, belt speed, and feed rate data in a real-time database and supports historical trend query and fault alarm functions. The data acquisition module collects data including real-time uploading of material level height at each discharge port by a radar level gauge, detection of total feed rate of the main belt by a belt scale, and feedback of ore particle size distribution by an online particle size analysis device.

6. The method for controlling particle size segregation in a large-scale semi-autogenous grinding feed according to claim 1, characterized in that: The method for controlling the material level at the surrounding discharge port includes: Peripheral material level deviation Δh i =Maximum height of material level at surrounding feed inlets h max -Minimum height h of material at the surrounding discharge port min When Δh i When the depth is greater than 0.5m, increase the frequency of the conveyor belt at the high-level feed inlet and decrease the frequency adjustment amount Δf at the low-level feed inlet. i Perform material level difference correction; The adjustment amount Δf i The formula for calculating Δf is: i =K p *Δh i +K i ∫Δh i dt+K d (dΔh) i / dt) Among them, K p K i K d The PID parameters are optimized through on-site debugging. After receiving the frequency adjustment command, the frequency converter completes the speed adjustment within 500ms to achieve the balance of the surrounding material levels. When h min When the material level is less than 0.5 meters, the conveyor belt will stop operating and an alarm will be triggered to prevent the material from hitting the feed nozzle when the material level is too low.

7. The method for controlling particle size segregation in a large-scale semi-autogenous grinding feed according to claim 1, characterized in that: The method for controlling the difference between the central material level and the surrounding material level includes: The difference between the center material level and the surrounding material level Δh0 = center material level height h1 - maximum height of the surrounding material outlet h max Keep Δh0 > L0 * 0.58, where L0 is the horizontal distance from the peripheral discharge port to the center discharge port; When Δh0 < L0 * 0.58, the frequency adjustment amount Δf of the surrounding feed inlet belt is increased as a whole. i This increases the discharge speed of the surrounding discharge ports; The adjustment amount Δf i The formula for calculating Δf is: i =K p *Δh0 +K i ∫Δh0dt+K d (dΔh0 / dt) Among them, K p K i K d The PID parameters are optimized through on-site debugging. After receiving the frequency adjustment command, the frequency converter completes the speed adjustment within 500ms, thereby adjusting the surrounding material level.

8. The method for controlling particle size segregation in a large-scale semi-autogenous grinding feed according to claim 1, characterized in that: The method for controlling the feed rate deviation includes: Feed rate deviation ΔQ = feed rate setpoint Q 设定值 - Actual ore feed rate Q total Control algorithm: Based on PID (Proportional-Integral-Derivative), the overall frequency adjustment Δf of each ore-collecting conveyor belt is calculated according to the feed rate deviation. i ; The adjustment amount Δf i The formula for calculating Δf is: i =K p *ΔQ +K i ∫ΔQdt+K d (dΔQ / dt) Among them, K p K i K d The PID parameters are optimized through on-site debugging. After receiving the frequency adjustment command, the frequency converter completes the speed adjustment within 500ms, thereby achieving dynamic balance of the output.

9. The method for controlling particle size segregation in a large-scale semi-autogenous grinding feed according to claim 1, characterized in that: Methods for controlling particle size deviation in semi-autogenous grinding feed include: Semi-autogenous grinding feed particle size deviation ΔD = semi-autogenous grinding feed particle size D(x) - historical average feed particle size D0. Control algorithm: based on PID control algorithm, calculate the frequency adjustment amount Δf of each ore collection belt according to the particle size deviation. i ; The adjustment amount Δf i The formula for calculating Δf is: i =K p *ΔD +K i ∫ΔDdt+K d (dΔD / dt) Among them, K p K i K d The PID parameters are optimized through on-site debugging. After receiving the frequency adjustment command, the frequency converter completes the speed adjustment within 500ms, thereby achieving dynamic balance of the feed particle size.

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