Comprehensive blasting method for controlling lumpiness and vibration of muck pile in surface mine blasting

Abstract

The invention discloses a comprehensive blasting method for controlling muck pile lumpiness and vibration in surface mine blasting, which comprises the following steps: S1, early-stage preparation and parameter calculation: investigating the geological condition of a mine in detail, and obtaining such information as rock physical and mechanical properties and joint fissure distribution; according to rock properties and mining requirements, blast hole parameters are determined; calculating initial delay detonation time according to a delay blasting rock breaking principle; s2, optimizing a charging structure: selecting a water medium interval charging structure, and determining the optimal unit consumption through theoretical analysis and field test; and based on the optimal unit consumption, establishing three-dimensional models of different water medium interval charging structures by adopting numerical simulation software, and selecting the optimal water medium interval charging structure. According to the method, the muck pile lumpiness is effectively controlled; the blasting vibration intensity is reduced; the blasting quality and the economic benefit are improved; the adaptability is high.

Description

Technical Field

[0001] The invention relates to the technical field of open-pit mine blasting, in particular to a comprehensive blasting method for controlling blast pile size and vibration in open-pit mine blasting. Background Art

[0002] In open-pit mining, blasting operations are a key link. However, traditional blasting methods often face the problems of large blast pile size and strong blasting vibration. Large blast pile size affects excavation and loading efficiency, increases transportation costs and secondary crushing processes, and consumes a lot of manpower, material and financial resources. Excessive blasting vibration not only threatens the safety of on-site personnel, but may also cause damage to the surrounding environment and adjacent buildings. Existing blasting technology has difficulty in accurately controlling blast pile size and vibration when dealing with different geological conditions, and cannot meet the mine's efficient, safe and environmentally friendly production needs. To this end, we propose a comprehensive blasting method for controlling blast pile size and vibration in open-pit mine blasting. Summary of the Invention

[0003] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a comprehensive blasting method for controlling the size and vibration of blast piles in open-pit mine blasting.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions: A comprehensive blasting method for controlling blast pile size and vibration in open-pit mine blasting comprises the following steps: S1. Preliminary preparation and parameter calculation: Conduct a detailed survey of the mine's geological conditions to obtain information on the rock's physical and mechanical properties, joint and fissure distribution, etc.; determine blasthole parameters based on rock properties and mining requirements; and calculate the initial delayed detonation time based on the principle of delayed blasting rock breaking. S2. Charge structure optimization: Select a water-interval charge structure and determine the optimal unit consumption through theoretical analysis and field tests. Based on the optimal unit consumption, use numerical simulation software to build three-dimensional models of different water-interval charge structures and select the optimal water-interval charge structure. S3. Numerical simulation and plan adjustment: Use numerical simulation software to simulate bench blasting, create a three-dimensional model of the bench, set model parameters and initiation method; monitor effective stress and blasting vibration, adjust blasting parameters based on simulation results, and determine the final blasting plan; S4. On-site blasting and effect monitoring: Carry out on-site blasting operations according to the determined blasting plan, and use high-precision detonators to achieve delayed detonation of each hole; monitor the blasting vibration speed, measure the size of the blast pile rock, evaluate the blasting effect, and optimize and improve the plan if it does not meet expectations.

[0005] Preferably, in step S1, geological drilling and geological radar technology are used to survey the geological conditions of the mine.

[0006] Preferably, in step S1, when determining the blasthole parameters, it is also necessary to consider the protection requirements of the surrounding environment, such as the safe distance from residential areas and important facilities, so as to adjust the angle and depth of the blasthole.

[0007] Preferably, in step S2, the optimal unit consumption of the water medium spaced charge structure is determined by conducting field tests under different unit consumptions.

[0008] Preferably, the numerical simulation software in step S3 is ANSYS / LS-DYNA software. When establishing the three-dimensional model, the rock material uses the MAT_RHT model, the explosive material uses the MAT_HIGH_EXPLOSIVE_BURN model, the air material uses the *MAT_NULL model, and the corresponding state equations are set.

[0009] Preferably, in step S4, industrial electronic detonators are used to achieve hole-by-hole delayed detonation.

[0010] Preferably, in step S4, the size of the blast pile rocks is determined by using split-desktop software to collect and analyze images of the top and front surfaces of the blast pile.

[0011] Preferably, in step S4, the blasting vibration velocity is monitored using a TC-4850 blasting vibration meter by setting monitoring points at different locations away from the blasting area for monitoring.

[0012] Preferably, in step S4, evaluating the blasting effect includes evaluating the blasting pile size distribution, blasting vibration velocity, foundation conditions, and dust concentration.

[0013] Compared with the prior art, the present invention has the following beneficial effects: 1. In the present invention, the size of the blast pile is effectively controlled. By optimizing the blasting parameters and the charge structure, the size of the blast pile is made more uniform, the rate of large pieces is significantly reduced, the excavation and transportation efficiency is improved, the secondary crushing process is reduced, and the production cost is reduced.

[0014] 2. In the present invention, the intensity of blasting vibration is reduced, and hole-by-hole delayed detonation and reasonable delay time are adopted, combined with a water medium interval charging structure, which effectively reduces the blasting vibration speed, reduces the impact on the surrounding environment and adjacent buildings, and improves the safety of blasting operations.

[0015] 3. In the present invention, the blasting quality and economic benefits are improved. The comprehensive blasting method increases the utilization rate of explosives, improves the blasting effect, makes mining more efficient and economical, and reduces dust pollution, which has good environmental benefits.

[0016] 4. The present invention has strong adaptability. The method takes into account the blasting requirements under different geological conditions. By combining numerical simulation and field tests, the blasting plan can be quickly adjusted to adapt to open-pit mine blasting operations in various complex geological environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a logic block diagram of a comprehensive blasting method for controlling blast pile size and vibration in open-pit mine blasting proposed by the present invention. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0019] Reference Figure 1 A comprehensive blasting method for controlling blast pile size and vibration in open-pit mine blasting comprises the following steps: S1. Preliminary preparation and parameter calculation: Conduct a detailed survey of the mine's geological conditions to obtain information on the rock's physical and mechanical properties, joint and fissure distribution, etc.; determine blasthole parameters based on rock properties and mining requirements; and calculate the initial delayed detonation time based on the principle of delayed blasting rock breaking. S2. Charge structure optimization: Select a water-interval charge structure and determine the optimal unit consumption through theoretical analysis and field tests. Based on the optimal unit consumption, use numerical simulation software to build three-dimensional models of different water-interval charge structures and select the optimal water-interval charge structure. S3. Numerical simulation and plan adjustment: Use numerical simulation software to simulate bench blasting, create a three-dimensional model of the bench, set model parameters and initiation method; monitor effective stress and blasting vibration, adjust blasting parameters based on simulation results, and determine the final blasting plan; S4. On-site blasting and effect monitoring: Carry out on-site blasting operations according to the determined blasting plan, and use high-precision detonators to achieve delayed detonation of each hole; monitor the blasting vibration speed, measure the size of the blast pile rock, evaluate the blasting effect, and optimize and improve the plan if it does not meet expectations.

[0020] In step S1, geological drilling and geological radar technology are used to survey the geological conditions of the mine.

[0021] In step S1, when determining the blasthole parameters, it is also necessary to consider the protection requirements of the surrounding environment, such as the safe distance from residential areas and important facilities, so as to adjust the angle and depth of the blasthole.

[0022] In step S2, the optimal unit consumption of the water medium spaced charge structure is determined by conducting field tests under different unit consumptions.

[0023] In step S3, the numerical simulation software is ANSYS / LS-DYNA software. When establishing the three-dimensional model, the MAT_RHT model is selected for rock material, the MAT_HIGH_EXPLOSIVE_BURN model is selected for explosive material, and the *MAT_NULL model is selected for air material, and the corresponding state equations are set.

[0024] In step S4, industrial electronic detonators are used to achieve hole-by-hole delayed detonation.

[0025] In step S4, the size of the blast pile rocks is determined by using split-desktop software to collect and analyze images of the top and front surfaces of the blast pile.

[0026] In step S4, the blasting vibration velocity is monitored using a TC-4850 blasting vibration meter by setting monitoring points at different locations away from the blasting area.

[0027] In step S4, the evaluation of the blasting effect includes the evaluation of the blasting pile size distribution, blasting vibration speed, foundation conditions, and dust concentration.

[0028] Working principle: S1. Preliminary preparation and parameter calculation: At a certain open-pit mine, a professional geological survey team used drilling and geological radar to conduct a detailed survey of the mine's geology. They determined physical and mechanical parameters such as rock velocity, density, compressive strength, tensile strength, internal friction angle, and cohesion, as well as information on the strike, dip, and density of joints and fissures. Based on this information and in accordance with mining requirements, they determined a blasthole diameter of 150 mm, a bench height of 12 m, a blasthole depth of 13.5 m, an over-depth of 1.5 m, a hole spacing of 6 m, and a row spacing of 5 m. Using the wall-pushing formula based on the rock collision hypothesis, they calculated the inter-row delay time to be 65 ms, taking into account the rock properties and explosive charge conditions at the site. For the inter-hole delay time, they used a semi-theoretical formula developed by the Changsha Research Institute of Mining and Metallurgy, initially calculating the inter-hole delay time to be between 16 and 31 ms.

[0029] S2. Optimization of charge structure: Considering the advantages of a water-interval charge structure in controlling blasting effectiveness, the mine decided to adopt a water-interval charge structure. Through a series of field tests, while ensuring blasting effectiveness, the unit explosive consumption was gradually reduced, ultimately determining the optimal unit explosive consumption of 0.34 kg / m³. Using ANSYS / LS-DYNA software, a 3D model of different water-interval charge structures was constructed. The rock mass in the model had lengths, widths, and heights of 800 cm, 400 cm, and 1450 cm, respectively, and the blasthole radius was 8.5 cm. Simulation analysis was performed for three charge structures: a 0.5 m water interval at the bottom of the charge and a 1.5 m water interval in the middle; a 1 m water interval at the bottom of the charge and a 1 m water interval in the middle; and a 1.5 m water interval at the bottom of the charge and a 0.5 m water interval in the middle. By observing the stress cloud map, equivalent stress time-history curve, rock damage range and free surface tensile crack area ratio, it was found that the charge structure with a water interval of 1m in the lower part and 1m in the middle had a long stress duration and slow decay, which could effectively avoid excessive rock crushing. The damage was evenly distributed along the axial direction of the blasthole and the range was regular. The free surface tensile crack area ratio was the highest, at 20.77%, and this structure was determined to be the optimal charge structure.

[0030] S3. Numerical simulation and scheme adjustment: A three-dimensional model of the bench was created using ANSYS / LS-DYNA software. Model material parameters were set: the MAT_RHT model was used for rock, the MAT_HIGH_EXPLOSIVE_BURN model for explosives, and the *MAT_NULL model for air. The corresponding equations of state were also configured. Reverse detonation was used, and stress and vibration monitoring points were set. Simulations of the bench blasting process were conducted under inter-hole delays of 16ms, 19ms, 22ms, 25ms, 28ms, and 31ms, monitoring the effective stress and blasting vibration at each monitoring point. Results showed that an inter-hole delay of 25ms resulted in a peak in the average maximum effective stress at each monitoring point, promoting better blasting and fragmentation. Furthermore, considering the blasting vibration velocity and the actual conditions of the test stope, a 25ms inter-hole delay was determined to be the optimal simulation delay, and the blasting plan was adjusted accordingly.

[0031] S4. On-site blasting and effect monitoring: On-site blasting operations were carried out according to the adjusted blasting plan. Industrial electronic detonators were used for delayed detonation per hole, with a 25ms delay between holes and a 65ms delay between rows. During the blasting process, monitoring points were set up at various locations near the blasting area using a TC-4850 blasting vibration meter to measure the blasting vibration velocity. After the blasting was completed, images of the top and front surfaces of the blast pile were captured using Split-Desktop software. Using a standard size 7 basketball as a dimensional reference, the images were imported into the software for processing and analysis. The results showed that 57.08% of the rock fragments on the top surface of the blast pile were smaller than 5 cm, with the largest fragment size being 24.36 cm. On the front surface of the blast pile, the largest fragment sizes were smaller than 10 cm and between 10 and 20 cm, accounting for 39.41% and 33.97%, respectively. Few fragments were larger than 50 cm, with the largest fragment size being 70.05 cm. Overall, the blasting results were excellent, meeting the mine's daily production needs. The blasting effect is evaluated based on the monitoring results. If it is found that the block size in some areas is large or the vibration exceeds the standard, it is analyzed that it may be due to local changes in geological conditions or charging deviations, and the blasting plan is optimized and modified in a targeted manner.

[0032] In summary, this scheme has the following advantages: Effective control of blasting pile size: By optimizing blasting parameters and charging structure, the blasting pile size is made more uniform, the rate of large pieces is significantly reduced, the excavation and transportation efficiency is improved, the secondary crushing process is reduced, and the production cost is reduced. Reduce blasting vibration intensity: The use of hole-by-hole delayed initiation and a reasonable delay time, combined with a water medium interval charging structure, effectively reduces the blasting vibration speed, reduces the impact on the surrounding environment and adjacent buildings, and improves the safety of blasting operations. Improve blasting quality and economic benefits: The comprehensive blasting method improves the utilization rate of explosives, improves the blasting effect, makes mining more efficient and economical, and reduces dust pollution, with good environmental benefits. Strong adaptability: This method takes into account the blasting needs under different geological conditions. Through a combination of numerical simulation and field tests, it can quickly adjust the blasting scheme to adapt to open-pit mine blasting operations in various complex geological environments.

[0033] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A comprehensive blasting method for controlling blast pile size and vibration in open-pit mine blasting, characterized in that: The following steps are involved: S1. Preliminary preparation and parameter calculation: Conduct a detailed survey of the mine's geological conditions to obtain information on the rock's physical and mechanical properties, joint and fissure distribution, etc.; determine blasthole parameters based on rock properties and mining requirements; and calculate the initial delayed detonation time based on the principle of delayed blasting rock breaking. S2. Charge structure optimization: Select a water-interval charge structure and determine the optimal unit consumption through theoretical analysis and field tests. Based on the optimal unit consumption, use numerical simulation software to build three-dimensional models of different water-interval charge structures and select the optimal water-interval charge structure. S3. Numerical simulation and plan adjustment: Use numerical simulation software to simulate bench blasting, create a three-dimensional model of the bench, set model parameters and initiation method; monitor effective stress and blasting vibration, adjust blasting parameters based on simulation results, and determine the final blasting plan; S4. On-site blasting and effect monitoring: Carry out on-site blasting operations according to the determined blasting plan, and use high-precision detonators to achieve delayed detonation hole by hole; Monitor the blasting vibration speed, measure the size of the blasted rock, evaluate the blasting effect, and optimize and improve the plan if it does not meet expectations.

2. A comprehensive blasting method for controlling blast pile size and vibration in open-pit mine blasting according to claim 1, characterized in that: In step S1, geological drilling and geological radar technology are used to survey the geological conditions of the mine.

3. The comprehensive blasting method for controlling blast pile size and vibration in open-pit mine blasting according to claim 1, characterized in that: In step S1, when determining the blasthole parameters, it is also necessary to consider the protection requirements of the surrounding environment, such as the safe distance from residential areas and important facilities, so as to adjust the angle and depth of the blasthole.

4. The comprehensive blasting method for controlling blast pile size and vibration in open-pit mine blasting according to claim 1, characterized in that: In step S2, the optimal unit consumption of the water medium spaced charge structure is determined by conducting field tests under different unit consumptions.

5. The comprehensive blasting method for controlling blast pile size and vibration in open-pit mine blasting according to claim 1, characterized in that: The numerical simulation software in step S3 is ANSYS / LS-DYNA software. When establishing the three-dimensional model, the rock material uses the MAT_RHT model, the explosive material uses the MAT_HIGH_EXPLOSIVE_BURN model, and the air material uses the *MAT_NULL model, and the corresponding state equations are set.

6. The comprehensive blasting method for controlling blast pile size and vibration in open-pit mine blasting according to claim 1, characterized in that: In step S4, industrial electronic detonators are used to achieve hole-by-hole delayed detonation.

7. The comprehensive blasting method for controlling blast pile size and vibration in open-pit mine blasting according to claim 1, characterized in that: In step S4, the size of the rock fragments in the blast pile is determined by using split-desktop software to collect and analyze images of the top and front surfaces of the blast pile.

8. The comprehensive blasting method for controlling blast pile size and vibration in open-pit mine blasting according to claim 1, characterized in that: In step S4, the blasting vibration velocity is monitored using a TC-4850 blasting vibration meter by setting monitoring points at different locations away from the blasting area.

9. The comprehensive blasting method for controlling blast pile size and vibration in open-pit mine blasting according to claim 1, characterized in that: In step S4, evaluating the blasting effect includes evaluating the blasting pile size distribution, blasting vibration speed, foundation conditions, and dust concentration.

Images