A method for determining the velocity of a naturally collapsing farad.

Abstract

This invention discloses a method for determining the bottom-pulling speed of the natural caving method, comprising the following steps: 1. Determining the hydraulic radius and calculating the minimum theoretical bottom-pulling area, using numerical simulation to obtain the minimum caving speed and the corresponding minimum simulated bottom-pulling area, and taking the larger of the two as the minimum bottom-pulling area for continuous caving of the ore body; 2. Calculating the required mining area based on the designed production scale, and taking the larger of the required mining area and the minimum bottom-pulling area for continuous caving of the ore body as the mining area for the production period; 3. Determining the maximum blockage rate based on block size analysis and calculating the redundancy coefficient in combination with the safety factor, and using this parameter to correct the mining area for the production period to obtain the minimum bottom-pulling area before the production period; 4. Calculating the reasonable bottom-pulling speed before reaching full production based on the bottom-pulling construction period. This invention solves the technical contradiction of excessively fast or slow bottom-pulling speed by quantitatively analyzing the dynamic matching relationship between bottom-pulling area, caving and ore release speed, taking into account initial infrastructure costs, production ramp-up efficiency and bottom structure stability.

Description

Technical Field

[0001] This invention relates to the field of mining engineering technology, and in particular to a method for determining the velocity of a natural caving farfalle. Background Technology

[0002] In the natural caving mining process, the bottom-pull operation is the core step in inducing ore and rock caving, and its technical rationality directly affects the stability and operational efficiency of the mining system. After the bottom-pull operation is completed, the upper ore body loses its support and caves under the action of gravity and ground pressure. Its technical value is mainly reflected in two aspects: first, it provides sufficient space to ensure the continuous ore and rock caving; second, by precisely controlling the bottom-pull size, it meets the initial caving requirements while minimizing disturbance to the surrounding rock mass.

[0003] However, controlling the caving speed presents a significant contradiction. If the caving speed is too fast, while it can accelerate the caving process, it significantly increases initial engineering investment and capital tied up, and can easily lead to a surge in early caving ore volume, resulting in ore accumulation, overloading of the bottom structure, and premature ground pressure damage. Conversely, if the caving speed is too slow, it will be difficult to meet production capacity requirements, the mining and beneficiation system will not operate at full capacity, resource development efficiency will decrease, and the return on initial investment will be difficult to achieve. Therefore, determining a reasonable caving speed has become a key technical challenge that naturally caving mines urgently need to solve. Summary of the Invention

[0004] The main technical problem to be solved by the present invention is to provide a method for determining the bottom speed of the natural collapse method in order to achieve balance.

[0005] To address the aforementioned technical problems, this invention provides a method for determining the velocity of a naturally collapsed fartherm, comprising the following steps:

[0006] Step 1: Determine the minimum base area for continuous caving of the ore body This step includes:

[0007] Step 11: Determine the hydraulic radius of the ore body during continuous collapse. The minimum theoretical base area for continuous caving of the ore body was calculated using theoretical analysis. ;

[0008] Step 12: Use numerical simulation to model and simulate the ore body caving process, and obtain the minimum caving velocity for the ore body to enter a continuous caving state. and the corresponding minimum simulated base area ;

[0009] Step 13: Take and The larger of the two is used as the minimum base area for the continuous collapse of the ore body. ;

[0010] Step 2: Determine the mining area during the production period This step includes:

[0011] Step 21: Determine the designed production scale as The caving rate of the ore body is The bulk density of the ore is The acceleration due to gravity is Calculate the required mining area for production capacity using formula ①. :

[0012] ①;

[0013] Step 22: Take and The larger of the two is used as the mining area during the production period. ;

[0014] Step 3: Introduce a redundancy coefficient for non-ore-producing areas To calculate the minimum base area before the production period This step includes:

[0015] Step 31: Perform block size analysis on the ore body to determine its maximum blockage rate in the early stage of caving. Take a safety factor of 1 Calculate the redundancy coefficient of the non-mining area according to formula ②. :

[0016] ②;

[0017] Step 32: Calculate the minimum base area before the production period according to formula ③. :

[0018] ③;

[0019] Step 4: Take the construction period of the bottom layer as Calculate the reasonable bottom-pulling speed before reaching full production capacity using formula ④. :

[0020] ④.

[0021] In a preferred embodiment, in step 11, the hydraulic radius of the ore body undergoing continuous collapse is determined. The method is as follows: substitute the corrected rock mass quality score of the ore body into the Laubscher caving diagram to obtain the result.

[0022] In a preferred embodiment, in step 11, the shape of the bottom-pulling area is rhomboid, and its interior angle is set to no more than 90°. Calculate the minimum theoretical base area for continuous caving of the ore body according to formula ⑥. :

[0023] ⑤.

[0024] In a preferred embodiment, in step 11, the base shape is square, and the minimum theoretical base area for continuous caving of the ore body is calculated according to formula ⑦. :

[0025] ⑥.

[0026] In a preferred embodiment, in step 31, the safety factor The value is 1.2.

[0027] In a preferred embodiment, in step 31, the software used for block size analysis of the ore body is BlockCave Fragmentation.

[0028] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0029] The method provided by this invention uses both theoretical analysis and numerical simulation to determine the minimum bottom area for continuous caving of the ore body, comprehensively considering the objective constraints of rock mass quality and caving mechanism on the bottom-pull parameters. The scheme then modifies the parameters by incorporating the designed production scale and the redundancy coefficient of the non-mining area, quantitatively deriving the minimum bottom area before the production period. This process is rigorous, with sufficient consideration of variables, and the redundancy coefficient of the non-mining area is determined based on block size analysis and safety factors, possessing high engineering reliability and ensuring the scientific nature of the bottom-pull speed calculation. Furthermore, the method dynamically matches the bottom-pull area, caving speed, ore release speed, and engineering cycle. These engineering parameters provide quantifiable decision-making basis for the progress control and risk pre-control of bottom-pull operations. Based on these two points, the method can scientifically determine a reasonable bottom-pull speed, balancing the initial infrastructure costs, production ramp-up efficiency, and bottom structure stability of natural caving mines. This effectively solves the technical contradiction of excessively fast or slow bottom-pull speeds, thereby improving the economic benefits and mining safety of the mine. Attached Figure Description

[0030] Figure 1 This is a flowchart illustrating the method described in an embodiment of the present invention. Detailed Implementation

[0031] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0032] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "top / bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0033] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed", "equipped", "sleeved / connected", "connected", etc., should be interpreted broadly. For example, "connection" can be a wall-mounted connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0034] like Figure 1 As shown, this embodiment of the invention provides a method for determining the natural caving farad velocity. This embodiment uses a low-grade porphyry copper mine as an example to illustrate the specific implementation process of the method. The mine is designed to produce 10,000 tons / day, and the implementation steps include:

[0035] Step 1: Determine the minimum base area for continuous caving of the ore body

[0036] First, the minimum theoretical base area for continuous caving of the ore body is calculated using theoretical analysis. (The subscript 't' refers to theoretical). The hydraulic radius of this copper ore body. Let be the ratio of the area to the perimeter of the base shape, and let the perimeter of the base region be . ,but:

[0037] , ①

[0038] Under the same hydraulic radius, the engineering work required for the rhomboid base-drawing zone is minimized. Let the side length of the base-drawing zone be... Its interior angles not exceeding 90° are Then the area of ​​the bottom region ,perimeter Substituting into equation ①, we get:

[0039] , ②

[0040] Transforming equation ②, we get:

[0041] , ③

[0042] Correspondingly, at this time:

[0043] ④

[0044] It is easy to see from equation ④ that if the amount of work required for the bottom-laying operation is to be minimized, then the maximum value should be selected based on the on-site construction conditions. To obtain the minimum theoretical base area Furthermore, where construction conditions permit, [further action will be taken]. That is, when the base area is a square, the minimum side length is obtained. Substituting into equation ④, we get .

[0045] Now determine the hydraulic radius The modified rock mass quality rating (MRMR) of this copper deposit is 53.5. Substituting this value into the Laubscher caving diagram, the hydraulic radius of the continued caving is determined. Not less than 29.5m. (By) Calculate the minimum theoretical base area required for continued collapse. It is 13924m².

[0046] Next, numerical simulation was used to determine the minimum simulated base area for continuous caving of the ore body. (The subscript 's' refers to simulation). The ore body caving process was modeled and simulated using FLAC3D software. The simulation results show that during the bottom-level advance simulation, when the caving rate remains at least 0.25 m / day, the ore body enters a state of continuous caving. The bottom-level area corresponding to this critical point is 16000 m². 2 In other words, numerical simulations were used to determine the minimum collapse velocity required for the ore body to enter a state of continuous collapse. and the corresponding minimum simulated base area The amounts are 0.25 m / day and 16,000 m respectively. 2 .

[0047] To ensure the reliability and safety of the parameters, the results obtained from both methods are used. and The larger value, 16,000 square meters, is taken as the minimum base area for continuous collapse of the ore body. (The subscript b refers to breaking).

[0048] Step 2: Calculate the mining area during the production period

[0049] According to the mining design plan, the spacing between ore-laying points is set at 15m × 15m, therefore the area of ​​a single ore-laying point is... 225m 2 Regarding the collapse speed Pick =0.25m / day, combined with the designed production scale of the mine For 10,000 tons / day and ore bulk density It is 27.80 kN / m³, and the acceleration due to gravity is taken. The formula for calculating the design production scale is as follows:

[0050] ⑤

[0051] The number of ore-discharging points during the production period was calculated. There are 64. Based on a ore discharge spacing of 15m × 15m, the required ore extraction area is determined by the designed production scale. It's not hard to understand. Alternatively, it can be directly calculated using the following equation (⑥):

[0052] ⑥

[0053] Because the bottom-digging operation needs to meet production capacity requirements and keep the ore body in a continuous collapse state, the area of ​​the mining area during the production period is limited. The required mining area for production capacity (Subscript p refers to production) and the minimum base area for continuous ore body collapse The larger of the two. Therefore, in this embodiment, the area of ​​the mining area during the production period is... The final measurement was 16,000 m².

[0054] Step 3: Determine the minimum base area before production.

[0055] To address the risks associated with natural caving, such as blockage by large ore fragments and instability of the bottom structure, this method introduces a redundancy coefficient for non-mining areas. This is done to reserve sufficient compensation space while ensuring the orderly release of collapsed ore. Specifically, the maximum blockage rate in the initial stage of collapse is determined using the block size analysis software BCF (Block Cave Fragmentation). By inputting the parameters of the rock structure plane group, strength parameters such as MRMR, and spatial parameters such as the attitude of the caving surface and the dimensions of the bottom structure, the software will provide the blockage rate at different caving heights and analyze the maximum blockage rate during the caving process. Simulations determined the maximum blockage rate during the initial stage of caving in this mine. The value is 25%, and a safety factor conventional in this technical field is used. The redundancy coefficient for non-mining areas is calculated to be 1.2. Then, based on the mining area during the production period... By deducing the minimum base area before the production period, (The subscript m refers to modified) means:

[0056] ⑦

[0057] Will , Substituting into equation ⑦, we get .

[0058] Step 4: Determine the appropriate rate of bottoming out before reaching full production capacity.

[0059] According to the mine's production plan, the infrastructure construction period is two years, which is the minimum construction period before reaching full production capacity. It takes 24 months. So, what is a reasonable rate of price reduction before reaching full production? for:

[0060]

[0061] In the above explanation, unless otherwise specified, m after a number represents meters, m² represents square meters, and m³ represents cubic meters.

[0062] The method provided in this invention uses both theoretical analysis and numerical simulation to determine the minimum bottom area for continuous caving of the ore body, comprehensively considering the objective constraints of rock mass quality and caving mechanism on the bottom-pull parameters. The scheme then modifies the parameters by combining the designed production scale and the redundancy coefficient of the non-mining area, quantitatively deriving the minimum bottom area before the production period. This process is rigorous, with sufficient consideration of variables, and the redundancy coefficient of the non-mining area is determined based on block size analysis and safety factors, possessing high engineering reliability and ensuring the scientific nature of the bottom-pull speed calculation. Furthermore, the method dynamically matches the bottom-pull area, caving speed, ore release speed, and engineering cycle. These engineering parameters provide quantifiable decision-making basis for the progress control and risk pre-control of bottom-pull operations. Based on these two points, the method can scientifically determine a reasonable bottom-pull speed, balancing the initial infrastructure costs, production ramp-up efficiency, and bottom structure stability of natural caving mines. This effectively solves the technical contradiction of excessively fast or slow bottom-pull speeds, thereby improving the economic benefits and mining safety of the mine.

[0063] The above description is merely a preferred embodiment of the present invention and is not intended to limit the patent scope of the present invention. Any technically equivalent modifications made based on the content of this specification shall fall within the protection scope of the present invention.

Claims

1. A method for determining the velocity of a naturally collapsing farfalle, characterized in that: Includes the following steps: Step 1: Determine the minimum base area for continuous caving of the ore body This step includes: Step 11: Determine the hydraulic radius of the ore body during continuous collapse. The minimum theoretical base area for continuous caving of the ore body was calculated using theoretical analysis. ; Step 12: Use numerical simulation to model and simulate the ore body caving process, and obtain the minimum caving velocity for the ore body to enter a continuous caving state. and the corresponding minimum simulated base area ; Step 13: Take and The larger of the two is used as the minimum base area for the continuous collapse of the ore body. ; Step 2: Determine the mining area during the production period This step includes: Step 21: Determine the designed production scale as The caving rate of the ore body is The bulk density of the ore is The acceleration due to gravity is Calculate the required mining area for production capacity using formula ①. : ①； Step 22: Take and The larger of the two is used as the mining area during the production period. ; Step 3: Introduce a redundancy coefficient for non-ore-producing areas To calculate the minimum base area before the production period This step includes: Step 31: Perform block size analysis on the ore body to determine its maximum blockage rate in the early stage of caving. Take a safety factor of 1 Calculate the redundancy coefficient of the non-mining area according to formula ②. : ②； Step 32: Calculate the minimum base area before the production period according to formula ③. : ③； Step 4: Take the base construction period as Calculate the reasonable bottom-pulling speed before reaching full production capacity using formula ④. : ④。 2. The method for determining the velocity of a naturally collapsing farfalle according to claim 1, characterized in that: In step 11, the hydraulic radius of the ore body during continuous collapse is determined. The method is as follows: substitute the corrected rock mass quality score of the ore body into the Laubscher caving diagram to obtain the result.

3. The method for determining the velocity of a naturally collapsing farfalle according to claim 1, characterized in that: In step 11, the shape of the bottom area is rhomboid, and its interior angles are set to no more than 90°. Calculate the minimum theoretical base area for continuous caving of the ore body according to formula ⑥. : ⑤。 4. The method for determining the velocity of a naturally collapsing farfalle according to claim 3, characterized in that: In step 11, the base shape is square, and the minimum theoretical base area for continuous caving of the ore body is calculated according to formula ⑦. : ⑥。 5. The method for determining the velocity of a naturally collapsing farfalle according to claim 1, characterized in that: In step 31, the safety factor The value is 1.

2.

6. The method for determining the velocity of a naturally collapsing farfalle according to claim 1, characterized in that: In step 31, the software used for block size analysis of the ore body is Block Cave Fragmentation.

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