Stope ore breaking method for combined blasting of presplitting blast holes and downward fan-shaped blast holes

Abstract

The invention discloses a stope ore breaking method for combined blasting of presplitting blast holes and downward fan-shaped blast holes. The method comprises the step that an ore body to be mined is divided into stopes of two steps according to the mining sequence. A stope connecting roadway, a rock drilling roadway and an ore removal roadway are constructed in the two stopes respectively, and a long anchor cable and anchor rod supporting system is adopted for providing pre-supporting. A cutting transverse roadway and an undercutting transverse roadway are constructed in a rock drilling roadway of a stope in the first step, a first cutting groove is formed through blasting, and a necessary free face and a compensation space are provided for subsequent downward fan-shaped blast hole blasting. Downward fan-shaped blast holes and presplitting blast holes are constructed in the rock drilling roadway of the first-step stope, and meanwhile only the presplitting blast holes are constructed in the rock drilling roadway of the second-step stope. And the downward fan-shaped blast holes and the presplitting blast holes of the stope in the first step are filled with explosives, and blasting is conducted in sequence. And after blasting is completed, gas flowing through the ore removal roadway is used for cleaning the stope so as to discharge foul gas, then residual ore is removed, and the goaf is filled.

Description

Technical Field

[0001] The present application relates to the technical field of metal mining, and in particular to a method for blasting ore in a stope by combining blasting of pre-splitting blastholes with downward fan-shaped blastholes. Background Art

[0002] At present, the open-pit subsequent filling mining method mainly adopts the method of downward vertical hole drilling and lateral blasting in the mining area. The downward vertical hole drilling has the advantages of uniform blasting energy distribution, small blasting block size, and controllable mining area blasting boundary, but it has the disadvantages of large exposed area of ​​the drilling chamber roof, great difficulty in controlling ground pressure, and poor drilling safety. Deep mining has become an important part of the mining industry. The mining of deep metal ores with thick and large ore bodies is mined under special conditions of strong disturbance and high ground pressure. If the traditional downward vertical hole drilling is still used for the mining of deep metal ores with thick and large ore bodies, it will lead to the collapse of the roof of the deep mining area drilling chamber, difficulty in support, and large loss and depletion of ore, which will seriously restrict the safe and efficient mining of deep mineral resources.

[0003] In recent years, with the development of rock drilling equipment, the rock drilling problem of downward fan-shaped holes has been solved. The use of downward fan-shaped hole drilling instead of downward vertical hole drilling will turn the top rock drilling chamber into a rock drilling tunnel. The rock drilling tunnel has the advantages of small roof exposure area and simple ground pressure control, which can greatly improve the safety of rock drilling operations and is more suitable for deep metal ore mining. In addition, downward fan-shaped hole drilling also has the advantages of small mining engineering volume, flexible blasthole arrangement, less movement of rock drilling equipment, short rock drilling auxiliary time, easy filling body bearing, and reduced stress concentration on the roof of the mining area. Therefore, downward fan-shaped hole drilling has important application prospects in deep metal ore mining.

[0004] However, downward fan-shaped hole drilling blasting has the problem of difficulty in controlling the blasting boundary of the stope, and the stope is seriously over-excavated and under-excavated. Summary of the invention

[0005] In view of this, an embodiment of the present application provides a method for dropping ore into a mine by combining blasting of pre-splitting blastholes with downward fan-shaped blastholes. By introducing the combined blasting technology of pre-splitting blastholes and downward fan-shaped blastholes, the advantages of pre-splitting blasting and downward fan-shaped blasting are fully utilized without adding additional mining approval engineering, thereby ensuring the smoothness of the mine boundary during the lateral blasting of the downward fan-shaped holes, reducing over-excavation and under-excavation of the mine, and reducing the disturbance of blasting vibration on both sides of the mine, so as to achieve the purpose of safe and efficient mining.

[0006] According to one aspect of the present application, a method for blasting a stope by combining pre-splitting blastholes with downward fan-shaped blastholes is provided, the method comprising: The stopes to be mined are divided into one-step stopes and two-step stopes perpendicular to the direction of the ore body according to the mining sequence; Constructing respective mine-site connecting tunnels, rock drilling tunnels, and mine-exit tunnels in the first-step mine and the second-step mine respectively, and using long anchor cables and bolt support systems to provide pre-support, constructing a cutting cross tunnel from the rock drilling tunnel of the first-step mine, and constructing a bottom cross tunnel from the mine-exit tunnel of the first-step mine; Constructing a first cutting rise in the cutting cross tunnel of the first-step stope, which is connected with the bottom cross tunnel of the first-step stope, and blasting the cutting cross tunnel of the first-step stope with the first cutting rise as a free surface and compensation space to form a first cutting groove, so as to provide a free surface and compensation space for the ore falling in the first-step stope through the first cutting groove; Constructing downward fan-shaped blastholes and pre-splitting blastholes in the rock drilling tunnel of the first-step stope, and constructing pre-splitting blastholes in the rock drilling tunnel of the second-step stope; Loading explosives into the downward fan-shaped blastholes and each pre-splitting blasthole of the first-step stope, and blasting each pre-splitting blasthole and the downward fan-shaped blastholes of the first-step stope in sequence; The first-step mine is cleaned by utilizing the gas flowing through the mining tunnel of the first-step mine, so that the dirty gas generated after cleaning is discharged through the rock drilling tunnel and the mine connecting tunnel of the first-step mine and the merging stage tunnel, and the first-step mine is filled after removing the residual ore in the first-step mine.

[0007] In an optional embodiment, the length of the first-step mining area is 20m~40m, the width of the first-step mining area is 12m~20m, and the height of the first-step mining area is the stage height; the length of the second-step mining area is 20m~40m, the width of the second-step mining area is 12m~18m, and the height of the second-step mining area is the stage height.

[0008] In an optional embodiment, the respective stope connection tunnels, rock drilling tunnels, and mine exit tunnels are constructed in the first-step stope and the second-step stope, and pre-support is provided by using a long anchor cable and an anchor support system, including: Constructing an upper stope joint tunnel from the stage tunnel to the first-step stope at the upper part of the stope, arranging a rock drilling tunnel in the upper stope joint tunnel of the first-step stope along the stope recovery direction, and using a long anchor cable and bolt support system to provide pre-support to maintain the stability of the upper stope joint tunnel and the rock drilling tunnel of the first-step stope, wherein the rock drilling tunnel of the first-step stope is arranged at the junction of the first-step stope and the second-step stope; An upper stope joint tunnel is constructed from the stage tunnel to the second-step stope at the upper part of the stope, a rock drilling tunnel is arranged in the upper stope joint tunnel of the second-step stope along the stope recovery direction, and a long anchor cable and bolt support system are used to provide pre-support to maintain the stability of the upper stope joint tunnel and the rock drilling tunnel of the second-step stope, wherein the rock drilling tunnel of the second-step stope is arranged at the junction of the first-step stope and the second-step stope, and the center line distance between the rock drilling tunnel of the second-step stope and the rock drilling tunnel of the first-step stope is the width of the first-step stope; A lower mining tunnel is constructed from the stage tunnel at the lower part of the mining field to the first-step mining field, and an exit tunnel is arranged along the mining direction in the lower mining tunnel of the first-step mining field, and pre-support is provided by a long anchor cable and anchor support system to maintain the stability of the exit tunnel of the first-step mining field.

[0009] In an optional embodiment, a first cutting rise connected to the bottom pull-out cross-tunnel of the first-step stope is constructed in the cutting cross-tunnel of the first-step stope, and the cutting cross-tunnel of the first-step stope is blasted to form a first cutting groove with the first cutting rise as a free surface and compensation space, so as to provide a free surface and compensation space for the first-step stope to drop ore through the first cutting groove, including: Constructing a first downward parallel medium-long hole from the cutting horizontal roadway of the first-step stope, and forming a first cutting rise based on the first downward parallel medium-long hole by using a medium-long hole blasting method, so that the first cutting rise is connected with the bottom pulling horizontal roadway of the first-step stope; A second downward parallel medium-depth hole is excavated in the cutting horizontal tunnel of the first-step mining area, and a first cutting groove is formed by segmented sequential blasting based on the second downward parallel medium-depth hole with the first cutting shaft as the free surface and compensation space, so as to provide a free surface and compensation space for ore dropping in the first-step mining area through the first cutting groove.

[0010] In an optional embodiment, constructing downward fan-shaped blastholes and pre-splitting blastholes in the rock drilling tunnel of the first-step stope, and constructing pre-splitting blastholes in the rock drilling tunnel of the second-step stope, comprises: In the rock drilling tunnel of the first-step stope, a rock drilling vehicle is used to construct downward fan-shaped blastholes and downward vertical holes as pre-splitting blastholes, wherein the diameter of the downward fan-shaped blastholes is 165 mm, the row spacing is 3 m, the hole bottom distance is 3.5 m, and the blasthole depth is 14 m to 52 m; the diameter of the pre-splitting blastholes in the first-step stope is 120 mm, the blasthole spacing is 1.2 m, and the blasthole depth is 46 m; A rock drilling vehicle is used to construct downward vertical holes as pre-splitting blastholes in the rock drilling tunnel of the second-step stope, wherein the pre-splitting blastholes of the second-step stope have a hole diameter of 120 mm, a blasthole spacing of 1.2 m, and a blasthole depth of 46 m.

[0011] In an optional embodiment, explosives are loaded into the downward fan-shaped blastholes and each pre-splitting blasthole of the first-step stope, and each pre-splitting blasthole and the downward fan-shaped blasthole of the first-step stope are blasted in sequence, including: An axially continuous radially uncoupled charge structure is used to load explosives into each pre-splitting blasthole, and a hole-forward detonation technique is used to blast each pre-splitting blasthole to form pre-cracks. A water column interval charging structure is used to load explosives into the downward fan-shaped blastholes in the first-step mining area, and the downward fan-shaped blastholes in the first-step mining area are blasted using hole-by-hole delay and hole bottom reverse detonation technology, wherein the detonation time of the pre-splitting blasthole is 50ms~100ms ahead of the detonation time of the downward fan-shaped blasthole.

[0012] In an optional embodiment, the diameter of the explosive loaded in each pre-splitting blasthole is 45mm, the blasting delay time of each pre-splitting blasthole is 0ms, and mining is withdrawn from the cutting groove to the end of the mining field. According to the mining direction, 12 pre-splitting blastholes are detonated each time; the diameter of the explosive loaded in the downward fan-shaped blastholes of the mining field in the first step is 120mm, the water column spacing ratio is 30%, the blasting delay time of the downward fan-shaped blastholes is 10ms~250ms, and blasting is carried out in a V-shaped detonation order of the middle and then the sides of the same row of blastholes, and mining is withdrawn from the cutting groove to the end of the mining field. According to the mining direction, two rows of blastholes are blasted each time.

[0013] In an optional embodiment, after removing the residual ore in the stope of the first step, filling the stope of the first step comprises: After removing the residual ore in the first-step mining area, repeat the steps of loading explosives into the downward fan-shaped blastholes and each pre-splitting blasthole in the first-step mining area, and blasting each pre-splitting blasthole and the downward fan-shaped blasthole in sequence until the first-step mining area is mined and the first-step mining area is filled.

[0014] In an optional embodiment, after the stope in step one is filled, the method further comprises: The two-step stope is mined and filled.

[0015] In an optional embodiment, the two-step stope is mined and filled, including: Constructing a lower stope joint tunnel from the stage tunnel to the second-step stope at the lower part of the stope, arranging a mine exit tunnel along the stope recovery direction in the lower stope joint tunnel of the second-step stope, and using a long anchor cable and bolt support system to provide pre-support to maintain the stability of the mine exit tunnel of the second-step stope; Construction of a cutting cross tunnel from the rock drilling tunnel of the second-step stope and construction of a bottom cross tunnel from the mining tunnel of the second-step stope; Constructing a third downward parallel medium-long hole from the cutting horizontal roadway of the second-step stope, and forming a second cutting rise based on the third downward parallel medium-long hole by using a medium-long hole blasting method, so that the second cutting rise is connected to the bottom pulling horizontal roadway of the second-step stope; A fourth downward parallel medium-length hole is excavated in the cutting horizontal tunnel of the two-step stope, and a second cutting groove is formed by segmented sequential blasting based on the fourth downward parallel medium-length hole with the second cutting rise as a free surface and compensation space, so as to provide a free surface and compensation space for ore dropping in the two-step stope through the second cutting groove; A rock drilling vehicle is used to construct downward fan-shaped blast holes in the rock drilling tunnel of the second-step stope, wherein the diameter of the downward fan-shaped blast holes is 165 mm, the row spacing is 3 m, the hole bottom distance is 3.5 m, and the blast hole depth is 14 m to 52 m; The downward fan-shaped blastholes of the two-step stope are charged with explosives by adopting a water column interval charging structure, and the downward fan-shaped blastholes of the two-step stope are blasted by adopting hole-by-hole delay and bottom-of-hole reverse detonation technology; wherein the diameter of the explosives charged in the downward fan-shaped blastholes of the two-step stope is 120 mm, the water column interval ratio is 30%, the blasting delay time of the downward fan-shaped blastholes of the two-step stope is 10 ms to 250 ms, and the blasting is carried out in a V-shaped detonation sequence of the middle and then the two sides of the same row of blastholes, and the mining is withdrawn from the cutting groove to the end of the stope, and two rows of blastholes are blasted each time according to the mining direction; The second-step mine is cleaned by utilizing the gas flowing through the mine exit tunnel of the second-step mine, so that the dirty gas generated after cleaning is discharged through the rock drilling tunnel and the mine connecting tunnel of the second-step mine and the merging stage tunnel. After removing the residual ore in the second-step mine, the steps of loading explosives in the downward fan-shaped blast holes of the second-step mine and blasting the downward fan-shaped blast holes of the second-step mine in sequence are repeated until the second-step mine is mined and the second-step mine is filled.

[0016] By means of the above technical scheme, the embodiment of the present application provides a method for ore dropping in a stope by blasting a combination of pre-splitting blastholes and downward fan-shaped blastholes. First, the ore body to be mined is divided into two-step stopes according to the mining order, namely, a one-step stope and a two-step stope, so as to ensure the orderly progress of the mining operation. In the two stopes, the stope connection tunnel, the rock drilling tunnel and the ore exit tunnel are constructed respectively, and the long anchor cable and the anchor support system are used to provide necessary pre-support to enhance the stability and safety of the tunnel. In the rock drilling tunnel of the one-step stope, a cutting cross tunnel and a bottom cross tunnel are constructed, and a first cutting groove is formed by blasting, which provides the necessary free surface and compensation space for the subsequent downward fan-shaped blasthole blasting. Downward fan-shaped blastholes and pre-splitting blastholes are constructed in the rock drilling tunnel of the one-step stope, and only pre-splitting blastholes are constructed in the rock drilling tunnel of the two-step stope. Explosives are loaded in the downward fan-shaped blastholes and each pre-splitting blasthole of the one-step stope, and blasting is carried out in sequence to achieve effective ore dropping. After the blasting is completed, the gas flowing through the mine tunnel is used to clean the mining area to discharge the dirty gas, and then the residual ore is removed and the goaf is filled to prepare for subsequent mining operations. This application introduces the combined blasting technology of pre-splitting blastholes and downward fan-shaped blastholes. Without adding additional mining and approval engineering, it fully utilizes the advantages of pre-splitting blasting and downward fan-shaped blasting to ensure the smoothness of the mining area boundary during the lateral blasting of the downward fan-shaped holes, reduce the over-excavation of the mining area, and reduce the disturbance of the blasting vibration on both sides of the mining area, so as to achieve the purpose of safe and efficient mining. At the same time, the scheme also optimizes the mining process, improves the recovery rate and mining efficiency of the ore, and provides strong support for the safe and efficient mining of deep metal deposits.

[0017] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings: Figure 1 A schematic flow chart of a method for blasting a mine in a stope by combining pre-splitting blastholes with downward fan-shaped blastholes provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0019] The present application will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that the embodiments and features in the embodiments of the present application can be combined with each other without conflict.

[0020] In this embodiment, a method for blasting a stope using a combination of pre-splitting blastholes and downward fan-shaped blastholes is provided. Figure 1 As shown, the method includes: Step 101, dividing the mining area to be mined into a first-step mining area and a second-step mining area perpendicular to the direction of the ore body according to the mining order.

[0021] Optionally, the length of the first-step mining area is 20m~40m, the width of the first-step mining area is 12m~20m, and the height of the first-step mining area is the stage height; the length of the second-step mining area is 20m~40m, the width of the second-step mining area is 12m~18m, and the height of the second-step mining area is the stage height.

[0022] In the embodiment of the present application, in order to reasonably plan the mining sequence and ensure the orderly progress of the mining operation, the stope is divided into a one-step stope and a two-step stope, and the mining process can be optimized according to the actual situation of the ore body and the mining conditions, and the mutual influence in the mining process can be reduced, making the mining process more orderly, reducing the confusion and uncertainty in the mining process, and improving the mining efficiency.

[0023] Step 102, construct respective mine connecting tunnels, rock drilling tunnels, and mine exit tunnels in the first-step mine and the second-step mine respectively, and use long anchor cables and anchor support systems to provide pre-support, construct cutting cross tunnels from the rock drilling tunnels of the first-step mine, and construct bottom cross tunnels from the mine exit tunnels of the first-step mine.

[0024] In the embodiment of the present application, in order to construct the tunnel system required for mining, necessary support measures are provided to ensure the safe conduct of mining operations. The construction of the mine-joining tunnel, rock drilling tunnel and mine-exit tunnel is the basis of mining operations, and the long anchor cable and anchor support system can provide a stable support effect to prevent the tunnel roof from collapsing. The mine-joining tunnel, rock drilling tunnel and mine-exit tunnel are constructed in the first-step mine and the second-step mine respectively, and the long anchor cable and anchor support system are used to provide pre-support, which improves the stability and safety of the tunnel system, reduces the risk of tunnel roof collapse, and ensures the safety of mining operations. In addition, the rock drilling tunnel of the first-step mine is constructed to cut the horizontal tunnel, and the bottom horizontal tunnel is constructed from the mine-exit tunnel of the first-step mine, so as to subsequently construct a cutting groove in the first-step mine.

[0025] Step 103, constructing a first cutting shaft connected with the bottom cross tunnel of the first-step mine in the cutting cross tunnel of the first-step mine, and blasting the cutting cross tunnel of the first-step mine with the first cutting shaft as a free surface and compensation space to form a first cutting groove, so as to provide a free surface and compensation space for ore falling in the first-step mine through the first cutting groove.

[0026] In the embodiment of the present application, in order to form a cutting groove in a one-step stope, a free surface and compensation space are provided for subsequent downward fan-shaped blasting. By constructing a first cutting rise in a one-step stope and using it as a free surface and compensation space for blasting, the required cutting groove can be formed, providing the necessary free surface and compensation space for the downward fan-shaped blasting, improving the blasting effect, and reducing the over-excavation and under-excavation phenomenon.

[0027] Step 104, constructing downward fan-shaped blastholes and pre-splitting blastholes in the rock drilling tunnel of the first-step stope, and constructing pre-splitting blastholes in the rock drilling tunnel of the second-step stope.

[0028] In the embodiment of the present application, downward fan-shaped blastholes and pre-splitting blastholes are arranged in the rock drilling tunnel to facilitate subsequent blasting operations. The downward fan-shaped blastholes are used for the main ore-dropping operation, while the pre-splitting blastholes are used to control the blasting boundary, reduce over-excavation and under-excavation, and improve the flexibility and controllability of the blasting operation.

[0029] Step 105, loading explosives into the downward fan-shaped blastholes and each pre-splitting blasthole in the stope of step one, and blasting each pre-splitting blasthole and the downward fan-shaped blasthole in the stope of step one in sequence.

[0030] In the embodiment of the present application, the ore dropping operation is realized by blasting the pre-splitting blastholes and the downward fan-shaped blastholes in sequence. The blasting of the pre-splitting blastholes can control the blasting boundary, while the blasting of the downward fan-shaped blastholes is used for the main ore dropping operation, which realizes the effective dropping of the ore and improves the safety and controllability of the blasting operation.

[0031] Step 106, using the gas flowing through the mining tunnel of the first-step mine to clean the first-step mine, so that the dirty gas generated after cleaning is discharged through the rock drilling tunnel and the mine connecting tunnel of the first-step mine and the merging stage tunnel, and the first-step mine is filled after removing the residual ore in the first-step mine.

[0032] In the embodiment of the present application, dirty gas and residual ore in the mining area are cleaned, and filling operations are performed to prepare for subsequent mining operations. By cleaning the mining area, dirty gas can be discharged to improve the working environment; removing residual ore can increase the recovery rate of ore; filling can reduce the impact of the goaf on subsequent mining operations, providing good conditions for subsequent mining operations.

[0033] By applying the technical solution of this embodiment, first, the ore body to be mined is divided into two-step stopes according to the mining order, namely, the one-step stope and the two-step stope, so as to ensure the orderly progress of the mining operation. In the two stopes, the stope connection tunnel, the rock drilling tunnel and the ore exit tunnel are constructed respectively, and the long anchor cable and the anchor support system are used to provide the necessary pre-support to enhance the stability and safety of the tunnel. In the rock drilling tunnel of the one-step stope, the cutting cross tunnel and the bottom cross tunnel are constructed, and the first cutting groove is formed by blasting, which provides the necessary free surface and compensation space for the subsequent downward fan-shaped blasting hole blasting. Downward fan-shaped blasting holes and pre-splitting blasting holes are constructed in the rock drilling tunnel of the one-step stope, and only pre-splitting blasting holes are constructed in the rock drilling tunnel of the two-step stope. Explosives are loaded in the downward fan-shaped blasting holes and each pre-splitting blasting hole of the one-step stope, and blasting is carried out in sequence to achieve effective ore falling. After the blasting is completed, the gas flowing through the mine tunnel is used to clean the mining area to discharge the dirty gas, and then the residual ore is removed and the goaf is filled to prepare for subsequent mining operations. This application introduces the combined blasting technology of pre-splitting blastholes and downward fan-shaped blastholes. Without adding additional mining and approval engineering, it fully utilizes the advantages of pre-splitting blasting and downward fan-shaped blasting to ensure the smoothness of the mining area boundary during the lateral blasting of the downward fan-shaped holes, reduce the over-excavation of the mining area, and reduce the disturbance of the blasting vibration on both sides of the mining area, so as to achieve the purpose of safe and efficient mining. At the same time, the scheme also optimizes the mining process, improves the recovery rate and mining efficiency of the ore, and provides strong support for the safe and efficient mining of deep metal deposits.

[0034] In the embodiment of the present application, optionally, respective stope joint tunnels, rock drilling tunnels, and mine exit tunnels are constructed in the first-step stope and the second-step stope, and pre-support is provided by using a long anchor cable and an anchor support system, including: Constructing an upper stope joint tunnel from the stage tunnel to the first-step stope at the upper part of the stope, arranging a rock drilling tunnel in the upper stope joint tunnel of the first-step stope along the stope recovery direction, and using a long anchor cable and bolt support system to provide pre-support to maintain the stability of the upper stope joint tunnel and the rock drilling tunnel of the first-step stope, wherein the rock drilling tunnel of the first-step stope is arranged at the junction of the first-step stope and the second-step stope; An upper stope joint tunnel is constructed from the stage tunnel to the second-step stope at the upper part of the stope, a rock drilling tunnel is arranged in the upper stope joint tunnel of the second-step stope along the stope recovery direction, and a long anchor cable and bolt support system are used to provide pre-support to maintain the stability of the upper stope joint tunnel and the rock drilling tunnel of the second-step stope, wherein the rock drilling tunnel of the second-step stope is arranged at the junction of the first-step stope and the second-step stope, and the center line distance between the rock drilling tunnel of the second-step stope and the rock drilling tunnel of the first-step stope is the width of the first-step stope; A lower mining tunnel is constructed from the stage tunnel at the lower part of the mining field to the first-step mining field, and an exit tunnel is arranged along the mining direction in the lower mining tunnel of the first-step mining field, and pre-support is provided by a long anchor cable and anchor support system to maintain the stability of the exit tunnel of the first-step mining field.

[0035] In this embodiment, in the upper part of the stope, the upper stope joint tunnel is constructed from the stage tunnel to the first step stope, and the rock drilling tunnel is arranged below the upper stope joint tunnel along the stope recovery direction. The rock drilling tunnel is arranged at the junction of the first step stope and the second step stope, so as to facilitate flexible rock drilling operations between the two stopes. Long anchor cables and bolt support systems are used to pre-support the upper stope joint tunnel and the rock drilling tunnel to ensure the stability and safety of the tunnel. Similarly, in the upper part of the stope, the upper stope joint tunnel is constructed from the stage tunnel to the second step stope. Along the stope recovery direction, the rock drilling tunnel is arranged below the upper stope joint tunnel. The rock drilling tunnel is also arranged at the junction of the first step stope and the second step stope, and maintains a certain center line distance (equal to the width of the first step stope) with the rock drilling tunnel of the first step stope to avoid mutual interference. Long anchor cables and bolt support systems are also used to provide pre-support. In the lower part of the mining area, the lower mining area joint tunnel is constructed from the stage tunnel to the first-step mining area. The mining tunnel is arranged below the lower mining area joint tunnel along the mining direction of the mining area. The mining tunnel is used for the transportation and discharge of ore, and its stability and safety are of vital importance. Long anchor cables and anchor support systems are also used to pre-support the lower mining area joint tunnel and the mining tunnel. The embodiment of the present application uses long anchor cables and anchor support systems to pre-support the mining area joint tunnel, rock drilling tunnel and mining tunnel, which can significantly enhance the stability and safety of the tunnel, help reduce the risk of tunnel roof collapse, and ensure the life safety and physical health of mining workers. The rock drilling tunnel is arranged at the junction of the first-step mining area and the second-step mining area, which is convenient for flexible rock drilling operations between the two mining areas, helps to optimize the mining process and improve mining efficiency.

[0036] In an embodiment of the present application, optionally, a first cutting rise connected to the bottom pull-out cross-lane of the first-step stope is constructed in the cutting cross-lane of the first-step stope, and the cutting cross-lane of the first-step stope is blasted to form a first cutting groove with the first cutting rise as a free surface and compensation space, so as to provide a free surface and compensation space for the ore falling in the first-step stope through the first cutting groove, including: Constructing a first downward parallel medium-long hole from the cutting horizontal roadway of the first-step stope, and forming a first cutting rise based on the first downward parallel medium-long hole by using a medium-long hole blasting method, so that the first cutting rise is connected with the bottom pulling horizontal roadway of the first-step stope; A second downward parallel medium-depth hole is excavated in the cutting horizontal tunnel of the first-step mining area, and a first cutting groove is formed by segmented sequential blasting based on the second downward parallel medium-depth hole with the first cutting shaft as the free surface and compensation space, so as to provide a free surface and compensation space for ore dropping in the first-step mining area through the first cutting groove.

[0037] In this embodiment, starting from the cutting horizontal tunnel of the first-step stope, the first group of downward parallel medium-deep holes (referred to as the first downward parallel medium-deep holes) are constructed downward. The medium-deep hole blasting method is adopted, and blasting is performed based on these medium-deep holes to form the first cutting skylight. This skylight needs to be connected with the bottom pulling horizontal tunnel of the first-step stope to provide the necessary free surface and compensation space for the subsequent blasting operation. In the cutting horizontal tunnel of the first-step stope, the second group of downward parallel medium-deep holes (referred to as the second downward parallel medium-deep holes) is excavated. Using the already formed first cutting skylight as the free surface and compensation space, the segmented sequential blasting is performed based on the second downward parallel medium-deep holes, that is, the blasting will be carried out in stages according to the predetermined order to ensure that the formation of the cutting groove meets the design requirements. Through this series of blasting operations, the first cutting groove is finally formed in the cutting horizontal tunnel. This cutting groove will provide the necessary free surface and compensation space for the ore dropping operation of the first-step stope, which will help optimize the blasting effect and reduce the over-excavation and under-excavation phenomenon. The embodiment of the present application can improve the blasting effect and provide favorable conditions for subsequent ore-dropping operations by accurately designing and constructing downward parallel medium-depth holes and using the first cutting shaft as a free surface and compensation space for segmented sequential blasting. Using the cutting groove as a free surface and compensation space for blasting can more effectively control the blasting boundary, help reduce over-excavation and under-excavation, and improve the recovery rate and mining efficiency of the ore.

[0038] In an embodiment of the present application, optionally, downward fan-shaped blastholes and pre-splitting blastholes are constructed in the rock drilling tunnel of the first-step mining site, and pre-splitting blastholes are constructed in the rock drilling tunnel of the second-step mining site, including: using a rock drilling vehicle to construct downward fan-shaped blastholes and downward vertical holes as pre-splitting blastholes in the rock drilling tunnel of the first-step mining site, wherein the aperture of the downward fan-shaped blastholes is 165 mm, the row spacing is 3 m, the hole bottom distance is 3.5 m, and the blasthole depth is 14 m~52 m, and the aperture of the pre-splitting blastholes in the first-step mining site is 120 mm, the blasthole spacing is 1.2 m, and the blasthole depth is 46 m; using a rock drilling vehicle to construct downward vertical holes as pre-splitting blastholes in the rock drilling tunnel of the second-step mining site, wherein the aperture of the pre-splitting blastholes in the second-step mining site is 120 mm, the blasthole spacing is 1.2 m, and the blasthole depth is 46 m.

[0039] In this embodiment, for a one-step stope, a rock drill is used in its rock drilling tunnel for construction, and the construction content includes downward fan-shaped blastholes and downward vertical holes (as pre-splitting blastholes). The specific parameters of the downward fan-shaped blastholes are: hole diameter 165mm, row spacing 3m, hole bottom distance 3.5m, and blasthole depth between 14m and 52m. The parameters of the pre-splitting blastholes (downward vertical holes) are: hole diameter 120mm, blasthole spacing 1.2m, and blasthole depth 46m. For a two-step stope, a rock drill is also used in its rock drilling tunnel for construction. The construction content is downward vertical holes, which are used as pre-splitting blastholes. The specific parameters of the pre-splitting blastholes are: hole diameter 120mm, blasthole spacing 1.2m, and blasthole depth 46m. This construction method ensures that the setting of blastholes in the stopes of different steps can meet the needs of mining, while ensuring the safety and efficiency of construction. By precisely controlling the aperture, spacing and depth of the blastholes, the scope and effect of the blasting can be effectively controlled to achieve the desired mining objectives.

[0040] In an embodiment of the present application, optionally, explosives are loaded into the downward fan-shaped blastholes and each pre-splitting blasthole of the first-step mining field, and each pre-splitting blasthole and the downward fan-shaped blasthole of the first-step mining field are blasted in sequence, including: using an axially continuous radially uncoupled charging structure to load explosives into each pre-splitting blasthole, and using the hole mouth forward detonation technology to blast each pre-splitting blasthole to form pre-cracks; using a water column interval charging structure to load explosives into the downward fan-shaped blastholes of the first-step mining field, and using hole-by-hole delay and hole bottom reverse detonation technology to blast the downward fan-shaped blastholes of the first-step mining field, wherein the detonation time of the pre-splitting blasthole is 50ms~100ms ahead of the detonation time of the downward fan-shaped blasthole.

[0041] In this embodiment, an axially continuous radially uncoupled charge structure is used to load explosives into each pre-splitting blasthole. This charge structure helps to form a smoother pre-crack during blasting and reduce damage to the surrounding rock mass. Each pre-splitting blasthole is blasted using a borehole forward detonation technique. Borehole forward detonation means that the detonator package is located at the mouth of the blasthole, which helps to ensure that the blasting wave can propagate evenly along the axial direction of the blasthole, thereby forming continuous pre-cracks. The detonation time of the pre-splitting blasthole needs to be ahead of the detonation time of the downward fan-shaped blasthole, and the specific advance time is 50ms to 100ms. Such a time difference can ensure that the pre-cracks have been formed before the blasting of the downward fan-shaped blasthole, thereby providing the necessary free surface and compensation space for the blasting of the downward fan-shaped blasthole, which helps to control the blasting range and optimize the blasting effect. A water column interval charge structure is used to load explosives into the downward fan-shaped blasthole of a one-step stope. The water column interval charge structure helps to reduce the shock wave and vibration effect during blasting, while improving the energy utilization rate of the explosives. The downward fan-shaped blastholes are blasted by using hole-by-hole delay and bottom-hole reverse detonation technology. The hole-by-hole delay detonation means that there is a certain interval between the detonation times of each blasthole, which helps to control the propagation direction and range of the blasting wave and reduce over-excavation and under-excavation. The bottom-hole reverse detonation means that the detonating charge is located at the bottom of the blasthole, which helps to ensure that the blasting wave can more effectively break the rock mass. The blasting of the downward fan-shaped blastholes needs to be carried out in a predetermined order to ensure that the blasting wave can propagate evenly and orderly, so as to achieve the expected mining effect.

[0042] In an embodiment of the present application, optionally, the diameter of the explosive loaded in each pre-splitting blasthole is 45 mm, the blasting delay time of each pre-splitting blasthole is 0 ms, and mining is withdrawn from the cutting groove to the end of the mining field. According to the mining direction, 12 pre-splitting blastholes are detonated each time; the diameter of the explosive loaded in the downward fan-shaped blastholes of the mining field in the first step is 120 mm, the water column spacing ratio is 30%, the blasting delay time of the downward fan-shaped blastholes is 10 ms~250 ms, and blasting is carried out in a V-shaped detonation order of the same row of blastholes first in the middle and then on both sides, and mining is withdrawn from the cutting groove to the end of the mining field. According to the mining direction, two rows of blastholes are blasted each time.

[0043] In this embodiment, the diameter of the explosive loaded in each pre-splitting blasthole is 45mm, which ensures that the explosive can effectively explode in the blasthole and reduces excessive damage to the blasthole wall. The blasting delay time of each pre-splitting blasthole is 0ms, and all pre-splitting blastholes of each blasting will be detonated simultaneously. Since the main purpose of the pre-splitting blasthole is to form a smooth crack in the rock mass, the simultaneous detonation can ensure the continuity and smoothness of the crack. From the cutting groove to the end of the stope, 12 pre-splitting blastholes are detonated each time according to the mining direction. Such detonation sequence and quantity selection are to ensure that during the mining process, the cracks in the rock mass can expand in a predetermined direction while reducing unnecessary damage to the surrounding rock mass. The diameter of the explosive loaded in the downward fan-shaped blasthole of the one-step stope is 120mm, and the water column spacing ratio is 30%. A larger explosive diameter can provide a stronger explosive force, and the water column spacing helps to reduce the damage of the explosion shock wave to the blasthole wall, while improving the energy utilization of the explosive. The delay time of the blast hole blasting for the downward fan-shaped blast holes is 10ms to 250ms. The delay time within this range ensures that the blast waves between the blast holes do not interfere with each other, thereby optimizing the blasting effect. The blasting is carried out in a V-shaped detonation sequence of the same row of blast holes, first in the middle and then on the sides. This detonation sequence ensures that the rock mass can be broken more evenly and orderly during the blasting process, reducing over-excavation and under-excavation. Withdrew from the cutting groove to the end of the stope, and blasted two rows of blast holes each time according to the direction of withdrawal. This selection of the number of detonations can reduce unnecessary damage to the surrounding rock mass while ensuring the blasting effect, and help control the mining progress.

[0044] In an embodiment of the present application, optionally, after removing the residual ore in the first-step mining area, the first-step mining area is filled, including: after removing the residual ore in the first-step mining area, repeating the steps of loading explosives in the downward fan-shaped blastholes and each pre-splitting blasthole in the first-step mining area, and blasting each pre-splitting blasthole and the downward fan-shaped blasthole in sequence until the first-step mining area is mined, and filling the first-step mining area.

[0045] In this embodiment, during the recovery process of the first-step stope, as the ore is gradually mined, some residual ore will be left. These residual ores need to be removed by appropriate means to prepare for subsequent filling work. The method of removing the residual ore may include mechanical excavation and other methods, and the specific selection depends on factors such as the nature of the ore, mining conditions, and cost-effectiveness. After removing the residual ore, it is necessary to repeatedly load explosives in the downward fan-shaped blastholes and each pre-splitting blasthole in the first-step stope, and blast them in sequence. The purpose of this step is to ensure that the ore in the stope is fully mined, and at the same time, the necessary blasting cracks are formed to facilitate the subsequent filling work. When the ore in the first-step stope is completely mined and the blasting cracks are formed to meet the requirements, the filling work can be carried out, and the materials support and manage the goaf to control the collapse of the surrounding rock and the subsidence of the surface, and create safe and convenient conditions for subsequent mining work. This process in the embodiment of the present application realizes the effective mining and filling management of the first-step stope by accurately controlling the steps of charging, blasting, and filling. Such a process helps optimize mining results and increase ore recovery while reducing damage to surrounding rock and mining costs.

[0046] In an embodiment of the present application, optionally, after the first-step mine is filled, the method further includes: mining and filling the second-step mine. Specifically: constructing a lower mine link tunnel from the stage tunnel to the second-step mine in the lower part of the mine, arranging a mine exit tunnel along the mine recovery direction in the lower mine link tunnel of the second-step mine, and using long anchor cables and anchor support systems to provide pre-support to maintain the stability of the mine exit tunnel of the second-step mine; constructing a cutting cross tunnel from the rock drilling tunnel of the second-step mine and constructing a bottom cross tunnel from the mine exit tunnel of the second-step mine; constructing a third downward parallel medium-depth hole from the cutting cross tunnel of the second-step mine, and using the medium-depth hole blasting method to form a second downward parallel medium-depth hole based on the third downward parallel medium-depth hole. A cutting shaft is provided to connect the second cutting shaft with the bottom horizontal lane of the second-step mining field; a fourth downward parallel medium-depth hole is excavated in the cutting horizontal lane of the second-step mining field, and a second cutting groove is formed by segmented sequential blasting based on the fourth downward parallel medium-depth hole with the second cutting shaft as the free surface and compensation space, so as to provide a free surface and compensation space for the ore falling in the second-step mining field through the second cutting groove; a rock drilling vehicle is used to construct downward fan-shaped blast holes in the rock drilling lane of the second-step mining field, wherein the aperture of the downward fan-shaped blast holes is 165 mm, the row spacing is 3 m, and the hole bottom distance is 1.5 m. The diameter of the explosives loaded into the downward fan-shaped blastholes of the two-step stope is 120 mm, the water column spacing ratio is 30%, the blasting delay time of the downward fan-shaped blastholes of the two-step stope is 10 ms to 250 ms, and the blasting is carried out in a V-shaped detonation order of the middle and then the two sides of the blastholes in the same row. Mining is withdrawn from the cutting groove toward the end of the mining area, and two rows of blast holes are blasted each time according to the mining direction; the second-step mining area is cleaned by utilizing the gas flowing through the mining tunnel of the second-step mining area, so that the dirty gas generated after cleaning is discharged through the rock drilling tunnel and the mining area connecting tunnel of the second-step mining area and the merging stage tunnel; after removing the residual ore of the second-step mining area, the steps of loading explosives in the downward fan-shaped blast holes of the second-step mining area and blasting the downward fan-shaped blast holes of the second-step mining area in sequence are repeated until the mining of the second-step mining area is completed and the second-step mining area is filled.

[0047] In this embodiment, the recovery and filling process of the two-step stope specifically includes: constructing a lower stope joint tunnel from the stage tunnel to the two-step stope at the lower part of the stope to provide a channel for the subsequent arrangement of the mine exit tunnel and mining work. Arrange the mine exit tunnel in the lower stope joint tunnel of the two-step stope along the stope recovery direction. Use long anchor cables and anchor support systems to provide pre-support to maintain the stability of the mine exit tunnel of the two-step stope and ensure safety during the mining process. Construct a cutting cross tunnel from the rock drilling tunnel of the two-step stope to provide a basis for subsequent medium-deep hole blasting and cutting groove formation. Construct a bottom cross tunnel from the mine exit tunnel of the two-step stope to facilitate subsequent mining work. Construct a third downward parallel medium-deep hole from the cutting cross tunnel of the two-step stope, and use the medium-deep hole blasting method to form a second cutting skylight based on the third downward parallel medium-deep hole, so that the second cutting skylight is connected to the bottom cross tunnel of the two-step stope. The fourth downward parallel medium-deep hole is excavated in the cutting horizontal tunnel of the second-step stope, and the second cutting skylight is used as the free surface and compensation space. The second cutting groove is formed by segmented sequential blasting based on the fourth downward parallel medium-deep hole. The second cutting groove provides a free surface and compensation space for the ore falling in the second-step stope to ensure that the ore can fall smoothly during the mining process. A rock drill is used in the rock drilling tunnel of the second-step stope to construct downward fan-shaped blast holes. The aperture of the downward fan-shaped blast holes is 165mm, the row spacing is 3m, the hole bottom distance is 3.5m, and the blast hole depth is 14m~52m. The water column interval charging structure is used to load explosives into the downward fan-shaped blast holes of the second-step stope. The diameter of the explosives is 120mm, and the water column interval ratio is 30%. The delay time of the blast hole blasting is 10ms~250ms, and the blasting is carried out in the V-shaped detonation sequence of the same row of blast holes first in the middle and then on both sides. Withdraw from the cutting groove to the end of the stope, and blast two rows of blastholes each time according to the direction of recovery. The second-step stope is cleaned by using the gas flowing through the mining tunnel of the second-step stope, and the dirty gas generated after cleaning is discharged through the rock drilling tunnel and the stope joint tunnel of the second-step stope into the stage tunnel, and the residual ore of the second-step stope is removed to prepare for subsequent recovery and filling work. Repeat the steps of loading explosives in the downward fan-shaped blastholes of the second-step stope, and blasting the downward fan-shaped blastholes of the second-step stope in sequence until the recovery of the second-step stope is completed, and the second-step stope is filled. In summary, this process in the embodiment of the present application realizes effective recovery and filling management of the two-step stope by accurately controlling the steps of stope preparation, cutting cross tunnel and bottom cross tunnel construction, cutting skylight and cutting groove formation, downward fan-shaped blasthole construction and blasting, stope cleaning and residual ore removal, and repeated charging and blasting. Such a process helps optimize mining results and increase ore recovery while reducing damage to surrounding rock and mining costs.

[0048] The beneficial effects of the stope ore dropping method using a combination of pre-splitting blastholes and downward fan-shaped blastholes provided in the embodiment of the present application are: (1) It reduces over-excavation and under-excavation of the stope, and solves the problem of difficulty in controlling the stope boundary during downward fan-shaped blasting. The pre-splitting blasthole can form a relatively flat fracture surface in advance, making the stope boundary relatively flat after the downward fan-shaped blasting.

[0049] (2) Reduce blasting vibration and surrounding rock damage. The pre-cracked blasthole is first blasted to form a pre-crack, which can serve as a barrier to reduce the impact of seismic waves generated by subsequent downward fan-shaped blasthole blasting on the surrounding environment and reduce surrounding rock damage.

[0050] (3) Improve blasting quality. The formation of pre-cracks can reduce the clamping effect of surrounding rock during blasting, isolate the propagation of blasting energy from the downward fan-shaped holes, make the rock mass after blasting more uniform, reduce the rate of large pieces, and improve the degree of ore crushing, which is beneficial to subsequent loading and transportation.

[0051] In summary, the blasting and ore-dropping technology combining pre-splitting blastholes and downward fan-shaped blastholes has obvious advantages in improving blasting effect, reducing over-excavation and under-excavation of the mining area, reducing mining and cutting costs, reducing blasting vibration, and preventing and controlling ground pressure. It is an advanced and worthy-to-promote blasting and ore-dropping technology in deep metal mining.

[0052] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0053] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A method for blasting a stope using a combination of pre-splitting blastholes and downward fan-shaped blastholes, characterized in that: The method comprises: The stopes to be mined are divided into one-step stopes and two-step stopes perpendicular to the direction of the ore body according to the mining sequence; Constructing respective mine-site connecting tunnels, rock drilling tunnels, and mine-exit tunnels in the first-step mine and the second-step mine respectively, and using long anchor cables and bolt support systems to provide pre-support, constructing a cutting cross tunnel from the rock drilling tunnel of the first-step mine, and constructing a bottom cross tunnel from the mine-exit tunnel of the first-step mine; Constructing a first cutting rise in the cutting cross tunnel of the first-step stope, which is connected with the bottom cross tunnel of the first-step stope, and blasting the cutting cross tunnel of the first-step stope with the first cutting rise as a free surface and compensation space to form a first cutting groove, so as to provide a free surface and compensation space for the ore falling in the first-step stope through the first cutting groove; Constructing downward fan-shaped blastholes and pre-splitting blastholes in the rock drilling tunnel of the first-step stope, and constructing pre-splitting blastholes in the rock drilling tunnel of the second-step stope; Loading explosives into the downward fan-shaped blastholes and each pre-splitting blasthole of the first-step stope, and blasting each pre-splitting blasthole and the downward fan-shaped blastholes of the first-step stope in sequence; The first-step mine is cleaned by utilizing the gas flowing through the mining tunnel of the first-step mine, so that the dirty gas generated after cleaning is discharged through the rock drilling tunnel and the mine connecting tunnel of the first-step mine and the merging stage tunnel, and the first-step mine is filled after removing the residual ore in the first-step mine.

2. The method for blasting a stope using a combination of pre-splitting blastholes and downward fan-shaped blastholes according to claim 1, characterized in that: The length of the first-step mining area is 20m~40m, the width of the first-step mining area is 12m~20m, and the height of the first-step mining area is the stage height; the length of the second-step mining area is 20m~40m, the width of the second-step mining area is 12m~18m, and the height of the second-step mining area is the stage height.

3. The method for blasting a stope using a combination of pre-splitting blastholes and downward fan-shaped blastholes according to claim 1, characterized in that: The respective stope connection tunnels, rock drilling tunnels, and mine exit tunnels are constructed in the first-step stope and the second-step stope, and pre-support is provided by using long anchor cables and bolt support systems, including: Constructing an upper stope joint tunnel from the stage tunnel to the first-step stope at the upper part of the stope, arranging a rock drilling tunnel in the upper stope joint tunnel of the first-step stope along the stope recovery direction, and using a long anchor cable and bolt support system to provide pre-support to maintain the stability of the upper stope joint tunnel and the rock drilling tunnel of the first-step stope, wherein the rock drilling tunnel of the first-step stope is arranged at the junction of the first-step stope and the second-step stope; An upper stope joint tunnel is constructed from the stage tunnel to the second-step stope at the upper part of the stope, a rock drilling tunnel is arranged in the upper stope joint tunnel of the second-step stope along the stope recovery direction, and a long anchor cable and bolt support system are used to provide pre-support to maintain the stability of the upper stope joint tunnel and the rock drilling tunnel of the second-step stope, wherein the rock drilling tunnel of the second-step stope is arranged at the junction of the first-step stope and the second-step stope, and the center line distance between the rock drilling tunnel of the second-step stope and the rock drilling tunnel of the first-step stope is the width of the first-step stope; A lower mining tunnel is constructed from the stage tunnel at the lower part of the mining field to the first-step mining field, and an exit tunnel is arranged along the mining direction in the lower mining tunnel of the first-step mining field, and pre-support is provided by a long anchor cable and anchor support system to maintain the stability of the exit tunnel of the first-step mining field.

4. The method for blasting a stope using a combination of pre-splitting blastholes and downward fan-shaped blastholes according to claim 1, characterized in that: A first cutting rise connected with the bottom pull-out lane of the first-step stope is constructed in the cutting lane of the first-step stope, and the cutting lane of the first-step stope is blasted to form a first cutting groove with the first cutting rise as a free surface and compensation space, so as to provide a free surface and compensation space for the ore falling in the first-step stope through the first cutting groove, including: Constructing a first downward parallel medium-long hole from the cutting horizontal roadway of the first-step stope, and forming a first cutting rise based on the first downward parallel medium-long hole by using a medium-long hole blasting method, so that the first cutting rise is connected with the bottom pulling horizontal roadway of the first-step stope; A second downward parallel medium-depth hole is excavated in the cutting horizontal tunnel of the first-step mining area, and a first cutting groove is formed by segmented sequential blasting based on the second downward parallel medium-depth hole with the first cutting shaft as the free surface and compensation space, so as to provide a free surface and compensation space for ore dropping in the first-step mining area through the first cutting groove.

5. The method for blasting a stope using a combination of pre-splitting blastholes and downward fan-shaped blastholes according to claim 1, characterized in that: Constructing downward fan-shaped blastholes and pre-splitting blastholes in the rock drilling tunnel of the first-step stope, and constructing pre-splitting blastholes in the rock drilling tunnel of the second-step stope, including: In the rock drilling tunnel of the first-step stope, a rock drilling vehicle is used to construct downward fan-shaped blastholes and downward vertical holes as pre-splitting blastholes, wherein the diameter of the downward fan-shaped blastholes is 165 mm, the row spacing is 3 m, the hole bottom distance is 3.5 m, and the blasthole depth is 14 m to 52 m; the diameter of the pre-splitting blastholes in the first-step stope is 120 mm, the blasthole spacing is 1.2 m, and the blasthole depth is 46 m; A rock drilling vehicle is used to construct downward vertical holes as pre-splitting blastholes in the rock drilling tunnel of the second-step stope, wherein the pre-splitting blastholes of the second-step stope have a hole diameter of 120 mm, a blasthole spacing of 1.2 m, and a blasthole depth of 46 m.

6. The method for blasting a stope using a combination of pre-splitting blastholes and downward fan-shaped blastholes according to claim 1, characterized in that: The method comprises: loading explosives into the downward fan-shaped blastholes and each pre-splitting blasthole of the first-step stope, and sequentially blasting each pre-splitting blasthole and the downward fan-shaped blasthole of the first-step stope, comprising: An axially continuous radially uncoupled charge structure is used to load explosives into each pre-splitting blasthole, and a hole-forward detonation technique is used to blast each pre-splitting blasthole to form pre-cracks. A water column interval charging structure is used to load explosives into the downward fan-shaped blastholes in the first-step mining area, and the downward fan-shaped blastholes in the first-step mining area are blasted using hole-by-hole delay and hole bottom reverse detonation technology, wherein the detonation time of the pre-splitting blasthole is 50ms~100ms ahead of the detonation time of the downward fan-shaped blasthole.

7. The method for blasting a stope using a combination of pre-splitting blastholes and downward fan-shaped blastholes according to claim 6, characterized in that: The diameter of the explosive loaded in each pre-splitting blasthole is 45mm, the blasting delay time of each pre-splitting blasthole is 0ms, and mining is withdrawn from the cutting groove to the end of the mining field. According to the mining direction, 12 pre-splitting blastholes are detonated each time; the diameter of the explosive loaded in the downward fan-shaped blastholes of the mining field in the first step is 120mm, the water column spacing ratio is 30%, the blasting delay time of the downward fan-shaped blastholes is 10ms~250ms, and blasting is carried out in a V-shaped detonation order of the same row of blastholes first in the middle and then on both sides, and mining is withdrawn from the cutting groove to the end of the mining field. According to the mining direction, two rows of blastholes are blasted each time.

8. The method for blasting a stope using a combination of pre-splitting blastholes and downward fan-shaped blastholes according to claim 7, characterized in that: After removing the residual ore in the first-step stope, the first-step stope is filled, comprising: After removing the residual ore in the first-step mining area, repeat the steps of loading explosives into the downward fan-shaped blastholes and each pre-splitting blasthole in the first-step mining area, and blasting each pre-splitting blasthole and the downward fan-shaped blasthole in sequence until the first-step mining area is mined and the first-step mining area is filled.

9. The method for blasting a stope using a combination of pre-splitting blastholes and downward fan-shaped blastholes according to any one of claims 1 to 8, characterized in that: After filling the stope in the first step, the method further comprises: The two-step stope is mined and filled.

10. The method for blasting a stope using a combination of pre-splitting blastholes and downward fan-shaped blastholes according to claim 9, characterized in that: The two-step stope is mined and filled, including: Constructing a lower stope joint tunnel from the stage tunnel to the second-step stope at the lower part of the stope, arranging a mine exit tunnel along the stope recovery direction in the lower stope joint tunnel of the second-step stope, and using a long anchor cable and bolt support system to provide pre-support to maintain the stability of the mine exit tunnel of the second-step stope; Construction of a cutting cross tunnel from the rock drilling tunnel of the second-step stope and construction of a bottom cross tunnel from the mining tunnel of the second-step stope; Constructing a third downward parallel medium-long hole from the cutting horizontal roadway of the second-step stope, and forming a second cutting rise based on the third downward parallel medium-long hole by using a medium-long hole blasting method, so that the second cutting rise is connected to the bottom pulling horizontal roadway of the second-step stope; A fourth downward parallel medium-length hole is excavated in the cutting horizontal tunnel of the two-step stope, and a second cutting groove is formed by segmented sequential blasting based on the fourth downward parallel medium-length hole with the second cutting rise as a free surface and compensation space, so as to provide a free surface and compensation space for ore dropping in the two-step stope through the second cutting groove; A rock drilling vehicle is used to construct downward fan-shaped blast holes in the rock drilling tunnel of the second-step stope, wherein the diameter of the downward fan-shaped blast holes is 165 mm, the row spacing is 3 m, the hole bottom distance is 3.5 m, and the blast hole depth is 14 m to 52 m; The downward fan-shaped blastholes of the two-step stope are charged with explosives by adopting a water column interval charging structure, and the downward fan-shaped blastholes of the two-step stope are blasted by adopting hole-by-hole delay and bottom-of-hole reverse detonation technology; wherein the diameter of the explosives charged in the downward fan-shaped blastholes of the two-step stope is 120 mm, the water column interval ratio is 30%, the blasting delay time of the downward fan-shaped blastholes of the two-step stope is 10 ms to 250 ms, and the blasting is carried out in a V-shaped detonation sequence of the middle and then the two sides of the same row of blastholes, and the mining is withdrawn from the cutting groove to the end of the stope, and two rows of blastholes are blasted each time according to the mining direction; The second-step mine is cleaned by utilizing the gas flowing through the mine exit tunnel of the second-step mine, so that the dirty gas generated after cleaning is discharged through the rock drilling tunnel and the mine connecting tunnel of the second-step mine and the merging stage tunnel. After removing the residual ore in the second-step mine, the steps of loading explosives in the downward fan-shaped blast holes of the second-step mine and blasting the downward fan-shaped blast holes of the second-step mine in sequence are repeated until the second-step mine is mined and the second-step mine is filled.

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