A method for determining the optimal material level height for production chute

Abstract

The present invention discloses a method for determining the optimal material level height applied to a production chute, so as to improve the safety and mining efficiency of the chute in an underground mine. By establishing a discrete element numerical model, the movement process of the ore in the chute is simulated, the fluidity coefficient is calculated, and the flow state of the ore is classified according to the change in the mass flow rate ratio. At the same time, the load extreme value coefficient is introduced to evaluate the impact characteristics of the bottom of the well under different material level heights. Finally, a reasonable material level height is obtained by combining the fluidity coefficient and the load extreme value coefficient, and its effectiveness is verified by field testing. This method can not only reduce the risks of collapse and blockage, but also provide a scientific basis for mine production, ensuring the continuity and safety of the mining process. Overall, the research provides a systematic decision-making tool for the management and operation of underground mines, which has broad practical application prospects.

Description

Technical Field

[0001] The invention belongs to the field of chute management and operation, and in particular relates to a method for determining an optimal material level height applied to a production chute. Background Art

[0002] A chute is a tunnel where ore falls by its own weight. It is widely used in the development of adit and shafts in underground mines. Over time, the chute will suffer wear and damage, leading to blockage and the risk of ore spraying, which is directly related to the production continuity of the mine. Therefore, it is particularly important to study the optimal material level. A reasonable material level should take into account the fluidity of the ore. If the material level is not appropriate, it is easy to cause problems such as poor ore flow and blockage, which may cause safety hazards in severe cases. The impact of the falling ore on the shaft wall and the ore below also needs to be paid attention to, affecting the stability of the shaft wall and the safety of the support structure.

[0003] The main influencing factors are:

[0004] Fluidity: Reduced ore fluidity is the root cause of blockage. To prevent blockage, the flow characteristics of the ore should be quantitatively evaluated and the flow state of the ore should be measured by the mass flow rate ratio (Rw):

[0005] Rw<0.855: Difficult flow, easy to clog;

[0006] 0.855≤Rw<1.0: flow is discontinuous;

[0007] 1.0≤Rw<1.333: continuous flow;

[0008] Rw≥1.333: The flow is too fast and there is a risk of "mine running away".

[0009] Load fluctuation: When the ore falls, it impacts the shaft wall. Reasonable material level height can reduce the damage to the shaft wall caused by the impact, and avoid compaction and blockage caused by excessive static or dynamic loads. Too high or too low material level will cause safety hazards to varying degrees.

[0010] Studying the optimal material level of the chute is of great significance to ensuring mine safety and stable ore discharge. By analyzing ore fluidity and load fluctuations, a scientific basis can be provided for the management and operation of the chute. Summary of the invention

[0011] The present invention aims to solve the technical problems existing in the background technology and to provide a method for determining the optimal material level height applied to a production chute.

[0012] In order to solve the technical problem, the technical solution of the present invention is:

[0013] A method for determining an optimal material level height for a production chute, taking into account fluidity and static and dynamic load effects, the method comprising:

[0014] S1: Problem definition and goal setting, determine the impact of ore retention height on ore fluidity and shaft safety;

[0015] S2: Calculation of fluidity coefficient, establishment of discrete element numerical model, simulation of ore movement in the chute, monitoring of movement information, verification of model accuracy by comparing numerical values ​​with experimental results, calculation of fluidity coefficient according to mass flow rate ratio, and classification;

[0016] S3: Load extreme coefficient analysis, establish a rock movement analysis model, analyze the falling characteristics of the rock in the inclined chute and its impact on the shaft wall, and calculate the load extreme coefficient according to different material level heights;

[0017] S4: Material level height determination: comprehensively consider the fluidity coefficient and load extreme value coefficient, calculate the material level height, and determine its rationality;

[0018] S5: Implementation and feedback: Apply the calculated optimal material level height in actual production, dynamically monitor ore flow and well wall status, and make adjustments and optimizations based on feedback.

[0019] Further, the step S2 specifically includes:

[0020] According to the structural characteristics and unloading conditions of underground mine production chute, a discrete element numerical model is established to simulate the movement of ore and rock during the chute unloading process, monitor the movement information of ore and rock, and analyze the movement of ore and rock; by comparing the results of numerical simulation with the experimental results, the rationality and accuracy of the numerical model results are verified;

[0021] According to the corresponding relationship between the mass flow rate ratio Rw and the ore flow state, the fluidity coefficient Ω is determined W :

[0022]

[0023] Further, the step S3 specifically includes:

[0024] In order to clarify the whole process movement characteristics of ore rock in the inclined chute and its impact with the shaft wall, the discrete element numerical simulation software is used to establish the ore rock movement analysis model in the chute ore falling process, simulate the ore rock movement process in the chute, study the ore rock movement characteristics in the chute, and analyze the movement characteristics of the ore rock falling in the chute and its impact on the shaft wall damage.

[0025] According to the influence of ore discharge process on the shaft wall at different material level heights, determine Φ σ :

[0026]

[0027] Further, the step S4 specifically includes:

[0028] When the material level height When the value is reasonable, the stress state of the bottom of the well is relatively stable during the ore falling process, the loose ore is not easy to compact when it meets water, and the impact between the well wall and the bottom of the well is minimal;

[0029]

[0030] After calculation, when When the material level height is the optimal material level height; when When the material level height The material level is too high to prevent compaction; or 0.5, the material level height

[0031] Compared with the prior art, the advantages of the present invention are:

[0032] (1) Based on the theory of ore fluidity and the effect of ore retention on the stress of the shaft wall and bottom, the ore flow state is measured by the mass flow rate ratio R w The static-dynamic load effect is used to determine the stress of the chute wall and bottom of the underground mine by retaining ore, and a solution for determining the optimal material level height of the underground mine production chute is formed.

[0033] (2) Using the PFC particle flow numerical simulation software, a numerical model of ore falling in the "Y"-shaped production chute of the Baixiangshan Iron Mine was established. The location where the ore in the chute first hits the chute wall was obtained. The first impact point is located about 20 m below the wellhead. The impact force of the first impact is the largest, and the damage to the chute wall is the greatest. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 , numerical model of branch chute ore falling;

[0035] Figure 2 , numerical model of ore discharge in chute;

[0036] Figure 3 , schematic diagram of the positions of the first and second impact points;

[0037] Figure 4 ,Contact force distribution diagram of the first four impact events;

[0038] Figure 5 , schematic diagram of the mine fall model;

[0039] Figure 6 , Model diagram of ore falling at different material levels;

[0040] Figure 7 , contact force-time diagram of bottom hole at different material level heights;

[0041] Figure 8 , maximum / minimum curve of bottom hole contact force at different material level heights. DETAILED DESCRIPTION

[0042] The specific implementation mode of the present invention is described below in conjunction with embodiments:

[0043] It should be noted that the structures, proportions, sizes, etc. shown in this specification are only used to match the contents disclosed in the specification so that people familiar with this technology can understand and read them, and are not used to limit the conditions under which the present invention can be implemented. Any structural modification, change in proportional relationship or adjustment of size should still fall within the scope of the technical content disclosed in the present invention without affecting the effects and purposes that can be achieved by the present invention.

[0044] At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" cited in this specification are only for the convenience of description and are not used to limit the scope of implementation of the present invention. Changes or adjustments to their relative relationships should be regarded as the scope of implementation of the present invention without substantially changing the technical content.

[0045] Embodiment 1:

[0046] The present invention proposes a method for determining the optimal material level height of a chute, and comprehensively considers the flow of ore in the chute and the static-dynamic load of the ore on the chute wall and bottom to determine the ore retention height:

[0047] (1) Fluidity coefficient Ω W

[0048] According to the structural characteristics and unloading conditions of underground mine production chute, a discrete element numerical model is established to simulate the movement of ore and rock during the chute unloading process, monitor the movement information of ore and rock, and analyze the movement of ore and rock. By comparing the results of numerical simulation with the experimental results, the rationality and accuracy of the numerical model results are verified.

[0049] According to the corresponding relationship between the mass flow rate ratio Rw and the ore flow state, the fluidity coefficient Ω is determined W :

[0050]

[0051] (2) Load extreme value coefficient Φ σ

[0052] In order to clarify the whole process movement characteristics of ore rock in the inclined chute and its impact with the shaft wall, discrete element numerical simulation software was used to establish an ore rock movement analysis model in the chute falling process, simulate the ore rock movement process in the chute, study the ore rock movement characteristics in the chute, and analyze the movement characteristics of the ore rock falling in the chute and its impact on the shaft wall damage.

[0053] When the material level height h is unreasonable, the value is too high or too low, the load on the bottom of the chute will be unstable, the loose ore and rock, the well wall and even the ore discharge structure at the bottom of the well will fluctuate greatly due to the impact, and compaction and blockage are likely to occur, which will have an adverse effect on the well wall, the well bottom support structure and the vibrating ore discharger.

[0054] According to the influence of ore discharge process on the shaft wall at different material level heights, determine Φ σ :

[0055]

[0056] (3) Material level determination

[0057] Material level height When the value is reasonable, the stress state of the bottom of the well is relatively stable during the ore falling process, the loose ore is not easy to harden when it comes into contact with water, and the impact between the well wall and the bottom of the well is minimized.

[0058]

[0059] After calculation, when When the material level height is the optimal material level height; when When the material level height The material level is too high to prevent compaction; or 0.5, the material level height

[0060] Embodiment 2:

[0061] Based on the optimal material level height of the "Y"-shaped production chute of Baixiangshan Iron Mine, the application status of the production chute of Baixiangshan Iron Mine is that since the construction of Baixiangshan Iron Mine started in 2003, the production chute has been in service for more than ten years, and there have been relatively serious wear and damage, as well as blockage and blowout. The sister mine Hemushan Iron Mine in the same region once had a chute that was damaged and could not be used due to failure to timely protect and manage it, and a new chute was excavated. On the one hand, the construction of a new chute will increase the investment in the mine, and on the other hand, the construction period will also affect the normal production of the mine, which is not conducive to the safety and economic benefits of the mine.

[0062] Numerical test of Y-shaped production chute:

[0063] (1) Establishment of ore falling model

[0064] According to the structural characteristics and unloading conditions of underground mine production chute, a discrete element numerical model is established to simulate the movement of ore and rock during the chute unloading process, monitor the movement information of ore and rock, and analyze the movement of ore and rock. The numerical simulation results are compared with the test results to ensure the rationality and accuracy of the numerical model.

[0065] PFC2D was used to establish the numerical model of the 60m "Y"-shaped chute in Baixiang Mountain ( Figure 1 ), ore flows out from the branch chute and falls into the vertical production chute, simulating the movement of ore and rock in the inclined chute, and analyzing the influence of the chute material level on the movement characteristics of ore and rock and the impact degree of the bottom of the well. The model has a total of 25 walls to distinguish the contact forces at different positions. Ore particles are released from the branch chute on one side. Under the action of gravity, the ore particles fall from the inclined branch chute into the upright production chute and fall on the ore stored at the bottom of the chute.

[0066] The particle size distribution of the ore particles in the model is shown in Table 1.

[0067] Table 1 Ore particle size distribution

[0068]

[0069] (2) Modeling of ore chute discharge

[0070] PFC2D particle flow software is used to establish a numerical simulation model for production chute discharge to study the flow characteristics of ore at different material levels. Figure 2 The schematic diagram of the model is shown in Figure 2. When constructing the model, the shaft wall of the ore storage section can be formed by the wall command, and the ore particles are generated by using a disk of unit thickness, and the radius of the particles ranges from 0.04 to 0.1 m. Table 2 shows other material parameters related to the numerical simulation.

[0071] Table 2 Numerical model parameters of shaft wall and ore materials

[0072]

[0073] According to the specific conditions of chute loading, ore particles fall from the top of the storage section in batches under their own gravity until the material level in the chute reaches the standard value set by the numerical simulation test. When conducting the simulation test of chute ore discharge, the setting of the material level height takes into account the actual needs of mine chute production management, and the specific heights are 15m, 12m and 10m respectively.

[0074] (3) Analysis of numerical test results

[0075] Before the ore enters the production chute, the accumulated ore first spreads at the front end, and the thickness decreases, thus starting to form an ore flow. The thickness of the center part of the ore flow is larger, while the thickness on both sides is smaller. As the density of the ore flow gradually decreases, the difference in thickness between the center and the two sides gradually decreases and tends to be consistent. When the front end of the ore flow begins to enter the chute, its flow state is relatively stable, and then the ore flow makes its first contact with the chute wall, located at wall No. 12 ( Figure 3 a), the ore is scattered after the collision. As the ore flow continues to fall, it will collide with the wall on the other side of the branch chute for the second time, at the No. 3 wall ( Figure 3 b).

[0076] When the ore particles fall in the production chute, there are three impact points, which are located about 20m below the wellhead, between 30m and 35m below the wellhead, and 60 to 65m below the wellhead. As the interval between the impact points increases, the impact angle gradually decreases.

[0077] like Figure 4 As shown in Table 3, the maximum contact force when each position of the production chute model impacts the ore particles is statistically calculated. The first impact point is hit the hardest, with a contact force of 14.42×10 6 N, corresponds to the ore being unloaded from the branch chute and having the first impact with the chute wall.

[0078] As the ore particles flow down the branch chute, the arrangement of the particles becomes more chaotic and the frequency is higher. The impact force of the first impact is the greatest, causing the greatest damage to the chute wall; the impact force of the second impact is 6.71×10 6 N, corresponds to the collision of ore particles from the first impact point after the first collision in the simulation process. After the first impact, some ore particles did not collide with the well wall, the frequency was slightly reduced, and the second collision; due to the energy consumption after the first collision, the amplitude of the second collision was relatively small and the frequency was low, which would not cause greater impact damage to the wall of the production chute.

[0079] After the ore has collided with the shaft wall twice and rubbed against each other, its kinetic energy is significantly reduced and its dispersion increases. Only a small amount of ore with low kinetic energy slightly scours the left shaft wall. This results in small-scale and mild scouring damage to various parts of the shaft wall.

[0080] As shown in Table 3, when the ore particles reach the bottom of the well, they are accelerated by gravity and the contact force is large, ranging from 9.94×10 6 N~10.67×10 6 N between.

[0081] Table 3 Contact forces at various positions of the production chute in the model

[0082]

[0083] The ore discharge process of the production chute at different material level heights was numerically simulated. The mass flow rate W0 under the test conditions was taken as the ore mass flow rate when the material level height was 12m, and the ore mass flow rate ratio under different material level height conditions was calculated. Then, according to the mass flow rate range of the ore, the flow state of the ore was divided, and the ore flow state under different material level height conditions was determined, as shown in Table 4. The chute material level height affects the flow rate of the ore.

[0084] Table 4 Numerical simulation results

[0085]

[0086] When the material level is too low or too high, the mass flow rate ratio Rw is small, the ore particles flow in intermittent flow, and the fluidity is poor. At this time, it is easy to form an arch and cause well blockage; when the material level is about 12m, the mass flow rate is relatively large, the ore particles flow in continuous flow, and the fluidity is good. In summary: the mass flow rate ratio Rw of ore particles increases first and then decreases with the increase of material level, and reaches the maximum value when the material level is 12m. At this time, the ore particles flow continuously and have the best fluidity.

[0087] Analysis of the chute falling process:

[0088] (1) Liquidity analysis

[0089] Table 5 summarizes the ore flow conditions corresponding to the actual value and test value of the material level height. When the material level height is between 10 and 12.5 m, the mass flow rate of the ore particles is R W As the material level increases, the mass flow rate increases. However, when the material level exceeds 12.5m, the mass flow rate is lower than R W It no longer rises, but begins to gradually decrease. When the material level is about 12.5m, the mass flow rate of ore particles is R W It reaches a peak value, indicating that the fluidity of the ore is better than that of the control experiment.

[0090] Table 5 Ore particle flow

[0091]

[0092] From the results of the ore-falling numerical model, it can be seen that when the material level is too low, the ore falling into the production chute will have a long falling distance, and will inevitably impact the shaft wall during the falling process, which is easy to cause damage to the shaft wall. The impact force of the ore in the upper part of the storage section on the lower ore and even the bottom structure of the shaft will increase nonlinearly, the bottom of the shaft will be subjected to excessive impact, the stability of the support structure will be affected, and the density of the ore in the lower part of the storage section will also increase.

[0093] In addition, when the material level is too high, the ore stored in the production chute will become too dense due to the combined effects of its own gravity and the adhesion and friction between particles, which will easily lead to the formation of compaction or even adhesion arches, affecting the fluidity of the ore and causing well blockage. When water seeps in, siltation or even blowout will occur.

[0094] (2) Extreme value analysis

[0095] The discrete element numerical simulation software is used to simulate the movement of ore and rock in the inclined chute, and the influence of the chute material level on the movement characteristics of ore and rock and the impact degree of the bottom of the well is analyzed. The focus is on analyzing the impact force of the falling ore on the bottom of the well at different material level heights, which provides a certain reference for the design, use, and maintenance of the chute. A numerical model of the ore falling process in the branch chute is established ( Figure 5 ), ore particles are released from the branch chute on one side. Under the action of gravity, the ore particles fall from the inclined branch chute into the upright production chute and fall on the ore already stored at the bottom of the chute.

[0096] A series of models with different material level heights were established for simulation ( Figure 6 ), the material level heights from left to right in the figure are 10m, 12.5m, 15m, 17.5m and 20m respectively. The ore falling from the branch chute has an impact on the ore already stored in the production chute. In view of this situation, the force at the bottom of each model with different material level heights is monitored to obtain the force curve from the beginning of ore falling to the last ore particle falling. The results are shown in the figure. Figure 7 The maximum and minimum values ​​of the bottom force of each model were counted to obtain the bottom force statistics table of different material level heights (Table 7).

[0097] The maximum and minimum values ​​of the force at the bottom of the production chute show a negative correlation with the increase of the material level. The maximum force at the bottom of the well increases with the increase of the material level, and the peak value appears at the material level of 20m. The minimum force decreases with the increase of the material level, and the peak value appears at the material level of 12.5m.

[0098] According to the statistical table of the force value of the bottom of the well during the ore falling process at different material levels, draw Figure 8 According to the overall trend of the curve, when the material level is 12.5m, the maximum force at the bottom of the well is lower than that at other material level heights, and the minimum value is also in a relatively moderate range. In addition, the difference between the maximum and minimum forces during the ore falling process is the lowest, which is 0.03784×10 7N. It can be inferred that when the material level of the production chute is about 12.5m, the ore accumulation body accumulated in the chute storage section during the ore dropping process is less affected by the impact of the ore falling from above than that at other material level heights, and the stress state is relatively stable. The loose ore and rock are not easy to form compaction, and the impact on the bottom support structure is also small.

[0099] Table 6 Force values ​​at the bottom of the mine at different material levels

[0100]

[0101] It is worth noting that when the material level exceeds 18m, the difference between the minimum and maximum bottom force increases suddenly, increasing to 0.13641×10 7 N is 2 to 4 times the height difference of other material levels. When the material level exceeds 18m, the ore storage section of the production chute and even the bottom of the well are in an unstable dynamic load state. In this state, the loose ore and rock are subject to large fluctuations in impact and are prone to compaction. The friction between the loose ore and rock and the well wall is more intense, and the damage to the well wall is more serious.

[0102] By analyzing the maximum and minimum values ​​of the material level during the chute discharge process, the following conclusions can be drawn:

[0103] The maximum value of material level height is 18m and the minimum value is 12m.

[0104] The maximum and minimum values ​​of the force at the bottom of the production chute show opposite trends with the increase of the material level. The maximum value of the force at the bottom of the well increases with the increase of the material level, and the peak value appears at the material level of 20m.

[0105] When the material level exceeds 18m, the ore storage section and bottom of the production chute are in an unstable dynamic load state. Under this state, the loose ore and rock are subject to large fluctuations in impact, which easily leads to compaction. The friction between the loose ore and rock and the well wall is more intense, and the well wall is more seriously damaged. When the dynamic load exceeds this limit, it is easy to cause a blowout accident.

[0106] When the material level is less than 12m, the ore storage section and bottom of the production chute are in an unstable high static load state. In this state, the ore and rock bulk are subjected to a high static load, which is easy to form compaction and block the well. When the static load exceeds this limit, it is easy to cause a blowout accident.

[0107] Optimal material level height of chute:

[0108] The appropriate material level height of the chute should fully consider the fluidity of the ore. After a series of numerical simulation experiments on the ore discharge process at different material level heights, the mass flow rate ratio R wThe results of this indicator show that when the material level is about 12m, the mass flow rate ratio reaches the maximum, the flow process of the ore particles is continuous and stable, the fluidity is good, and there will be no intermittent flow or blockage. When the material level is greater than 12.5m or less than 12m, the mass flow rate ratio decreases, and the ore particles show intermittent flow. Taking into account the actual conditions of the surrounding rock stability, silt sand ratio, water content, etc. of the Baixiangshan Iron Mine production chute, it is advisable to control the material level height at 12±2m.

[0109] In addition to considering the fluidity of the ore, the selection of the material level height should also consider the degree of impact on the ore below, the shaft wall and the bottom of the shaft during the ore falling in the chute. When the ore is unloaded into the shaft from the branch chute or the production chute, it will inevitably hit the shaft wall and fall on the accumulated ore below, causing impact on the ore bulk and even the bottom support structure. After numerical simulation of the ore falling process at different material level heights (10m~12m), it was found that when the material level height was 12.5m, the difference between the maximum and minimum forces at the bottom of the shaft reached the minimum, the stress state of the bottom of the shaft was the most stable during the entire ore falling process, the ore bulk was not easy to form a compaction, and the impact on the shaft wall and the bottom of the shaft was also the smallest.

[0110] It is worth noting that when the material level exceeds 18m, the difference between the maximum and minimum forces at the bottom of the well increases sharply, which is 2 to 4 times the difference at other material level heights. This situation shows that compared with lower material level heights, when the material level exceeds 18m, the load on the bottom of the well is unstable, the ore and rock bulk, the well wall and even the well bottom structure are subject to greater fluctuations due to impact, and compaction and blockage are prone to occur, which has an adverse effect on the well wall and the well bottom support structure.

[0111] Therefore, considering the impact of ore bulk and bottom structure, the optimal material level height of 60m chute is 12.5m. As production gradually shifts to deeper areas, according to the actual needs of production and transportation, high and deep chutes with a height of more than 100 meters appear. The material level height should not exceed 20m, otherwise it will have an adverse effect on the shaft wall and bottom structure.

[0112] in conclusion:

[0113] (1) Based on the theory of ore fluidity and the effect of ore retention on the stress of the shaft wall and bottom, the ore flow state is measured by the mass flow rate ratio R w The static-dynamic load effect is used to determine the stress of the chute wall and bottom of the underground mine by retaining ore, and a solution for determining the optimal material level height of the underground mine production chute is formed.

[0114] (2) Using the PFC particle flow numerical simulation software, a numerical model of ore falling in the "Y"-shaped production chute of the Baixiangshan Iron Mine was established. The location where the ore in the chute first hits the chute wall was obtained. The first impact point is located about 20 m below the wellhead. The impact force of the first impact is the largest, and the damage to the chute wall is the greatest.

[0115] (3) The optimal material level height for the Baixiangshan Iron Mine’s “Y”-shaped 60m high production chute is 12.5m. The ore forms a stable flow state in the chute, the loose ore and rock are not easy to form a compaction, and the impact on the bottom support structure is also small. The optimal material level height should be 12.5m.

[0116] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in this field without departing from the purpose of the present invention.

[0117] Many other changes and modifications may be made without departing from the concept and scope of the present invention.It should be understood that the present invention is not limited to the specific embodiments, and the scope of the present invention is defined by the appended claims.

Claims

1. A method for determining the optimal material level height for a production chute, characterized in that: Taking into account the effects of fluidity and static and dynamic loads, the method includes: S1: Problem definition and goal setting, determine the impact of ore retention height on ore fluidity and shaft safety; S2: Calculation of fluidity coefficient, establishment of discrete element numerical model, simulation of ore movement in the chute, monitoring of movement information, verification of model accuracy by comparing numerical values ​​with experimental results, calculation of fluidity coefficient according to mass flow rate ratio, and classification; S3: Load extreme coefficient analysis, establish a rock movement analysis model, analyze the falling characteristics of the rock in the inclined chute and its impact on the shaft wall, and calculate the load extreme coefficient according to different material level heights; S4: Material level height determination: comprehensively consider the fluidity coefficient and load extreme value coefficient, calculate the material level height, and determine its rationality; S5: Implementation and feedback: Apply the calculated optimal material level height in actual production, dynamically monitor ore flow and well wall status, and make adjustments and optimizations based on feedback.

2. The method for determining the optimal material level height for a production chute according to claim 1, characterized in that: The method comprises: Step S2 specifically comprises: Considering the structural characteristics and unloading conditions of underground mine production chute, a discrete element numerical model is established to simulate the movement of ore and rock during chute unloading, monitor the movement information of ore and rock, and analyze the movement of ore and rock; by comparing the results of numerical simulation with the experimental results, the rationality and accuracy of the numerical model results are verified; According to the corresponding relationship between the mass flow rate ratio Rw and the ore flow state, the fluidity coefficient Ω is determined W :

3. The method for determining the optimal material level height for a production chute according to claim 1, characterized in that: The method comprises: Step S3 specifically comprises: In order to clarify the whole process movement characteristics of ore rock in the inclined chute and its impact with the shaft wall, the discrete element numerical simulation software is used to establish the ore rock movement analysis model in the chute ore falling process, simulate the ore rock movement process in the chute, study the ore rock movement characteristics in the chute, and analyze the movement characteristics of the ore rock falling in the chute and its impact on the shaft wall damage. According to the influence of ore discharge process on the shaft wall at different material level heights, determine Φ σ :

4. The method for determining the optimal material level height for a production chute according to claim 1, characterized in that: The method includes: Step S4 specifically includes: When the material level height When the value is reasonable, the stress state of the bottom of the well is relatively stable during the ore falling process, the loose ore is not easy to compact when it meets water, and the impact between the well wall and the bottom of the well is minimal; After calculation, when When the material level height is the optimal material level height; when When the material level height The material level is too high to prevent compaction; or 0.5, the material level height

Images