Simple method for drawing floor of large structure stope

Abstract

The application provides a large-structure stope simple floor drawing method, calculates rock drilling and blasting parameters according to the American Livingston formula, constructs a downward large-diameter deep hole and a floor drawing roadway according to the obtained blasting parameters, extends and expands the upper mining blast hole depth to the trench bottom structure platform, adopts a variable multi-type section size spherical charge intensive blasting technology, a precise roof blasting technology, a deep hole small lateral positioning blasting and ore breaking technology and other means for the extended blast hole, forms a stable, standard and available new trench type bottom structure under the guarantee of the precise blasting technology, realizes safe and efficient floor drawing and slotting, has simple process and small construction difficulty, effectively avoids the safety risk caused by long-time cyclic operation of personnel under the roof, significantly improves the floor drawing efficiency and safety, and reduces the production cost, and the method has good popularization and application prospect for thick and large ore body large structure parameters in forming a trench type bottom structure.

Description

Technical Field

[0001] This invention relates to the field of mining technology, and in particular to a simple bottom-pulling method for large-structure stopes. Background Technology

[0002] In China, thick ore bodies are generally classified as large-structure stopes, with dimensions typically ranging from (40-50) × (15-20) × (50-60) m. The primary mining method used is downhole deep-hole stage stope mining, which is characterized by its large stope scale, high efficiency, low safety risk, and high capacity. However, to safely, reliably, and comprehensively remove all collapsed ore, a good bottom structure is necessary. Currently, there are two main types of bottom structures: trench-type and flat-bottomed. Currently, the formation of the bottom structure generally involves artificial shallow-hole or uphole medium-deep-hole blasting, resulting in dimensions of (40-50) × (15-20) × (10-20) m. This is achieved by workers directly entering the stope bottom for construction, which suffers from low efficiency and high risk.

[0003] Trench-type bottom structures are a common ore-receiving form in metal mines. Traditional methods, such as upward fan-shaped medium-deep hole blasting, are generally employed. However, this method is inefficient, difficult, and unsafe, especially in stopes using large-diameter deep-hole mining, which further hinders overall production efficiency. For the mining of thick ore bodies such as iron and copper mines using downward deep-hole staged stopes, a simple, rapid, and safe bottom-pulling method needs to be developed.

[0004] In view of this, it is necessary to design an improved method for simple bottom-pulling in large-structure mining areas to solve the above problems. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a simple bottom-laying method for large-structure mining areas, which is suitable for bottom-laying construction methods using trench-type or flat-bottomed structures.

[0006] To achieve the above objectives, the present invention provides a simple bottom-laying method for large-structure mining areas, comprising the following steps:

[0007] S1. According to the Livingston formula (USA) Calculate the rock drilling and blasting parameters, where L e Critical burial depth, m; E is the strain energy coefficient; Q represents the weight of the spherical explosive charge, kg; the optimal burial depth and explosive consumption are obtained by using single-hole blasting with gradually varying hole depth on the rock mass to be blasted, and the actual blasting parameters are obtained based on the calculated parameters.

[0008] S2. In the upper drilling chamber, according to the predicted ore body boundary line, construct the bottom-pull roadway and several downward large-diameter deep holes according to the blasting parameters obtained in step S1. The bottom-pull length is the stope length.

[0009] S3. The spherical explosive charge intensive blasting technology and the precision top-pressing blasting technology are used to blast the extension holes in the middle position to pull the bottom. The bottom-pressing roadway is used as a compensation space. The amount of explosive charge and the blasting range are determined according to the influence range of blasting vibration and the overall construction arrangement requirements. The number of blasting holes is determined according to the amount of explosive charge. Digital detonators are used to detonate in stages in the holes. The same method is used to carry out two top-pressing blasts.

[0010] S4. Use small lateral positioning blasting technology to blast the entire row or part of the continuous blast holes on both sides of the middle hole position. Use the space formed by the blasting of the middle row as the free compensation space. The height of the lateral collapse blasting depends on the height of the blasting of the middle row. The hole depth direction is formed by one or two blasts. Use the same method to laterally blast the blast holes corresponding to the entire row of the outermost hole to form a complete and standardized trench bottom structure.

[0011] S5. The loader enters the bottom structure from the ore outlet through the ore outlet roadway along the vein to load and shovel out the ore.

[0012] As a further improvement of the present invention, in step S2, the length of the mining area is 40-50m, and the specification of the bottom roadway is 3-5m.

[0013] As a further improvement of the present invention, in step S3, the number of extension holes in the intermediate hole position is 15 to 25; the charging method is to charge 30 to 35 kg of explosive per hole, and fill the area above the explosive surface with 1.5 to 2 m of fine sand or rock drilling debris. The height of the top blast is 2 to 3 m.

[0014] As a further improvement of the present invention, in step S4, the charging method of the small lateral positioning blasting technology is the same as in step S3. The lateral blasting height is ≤5m.

[0015] As a further improvement to this invention, all blasting is controlled below the trench platform, and the hole depth of each row and each hole is formed according to the slope of the trench platform. The hole deviation rate is ≤1m.

[0016] The angle of the trench platform is 40-50°, and the height of the bottom trench is 8-10m.

[0017] The beneficial effects of this invention are:

[0018] This invention provides a simple bottom-pulling method for large-structure stopes. Based on the Livingston formula, drilling and blasting parameters are calculated. Following these parameters, large-diameter deep boreholes and bottom-pulling roadways are constructed. By extending the depth of the upper mining blast holes to the bottom structural platform of the trench, the extended blast holes utilize techniques such as intensive blasting with spherical explosive charges of variable cross-section sizes, precision top-pressure blasting, and deep-hole small-lateral-positioning blasting. With precise blasting control, a stable, standard, and usable new trench-type bottom structure is formed, achieving safe and efficient bottom-pulling and trenching. The process is simple, construction is easy, and safety is high.

[0019] This invention extends the downward blasting boreholes to a certain extent into the bottom structure to be excavated. Within these deep holes, precise control of blasting technology prioritizes the aggregation of the extended and expanded boreholes, thereby forming an ideally designed receiving platform slope. Simultaneous blasting of multiple holes or rows of holes ultimately forms a standard, complete, and regular trench-shaped bottom structure. This improves the efficiency of bottom structure construction in large-diameter deep-hole mining areas and enhances the level and degree of safe production.

[0020] This invention effectively avoids the safety risks caused by personnel working in a loop under the roof for a long time, significantly improves the efficiency and safety of bottom pulling, and reduces production costs. This method has a good prospect for promotion and application when forming trench-type bottom structures in thick ore bodies with large structural parameters. Attached Figure Description

[0021] Figure 1 A cross-sectional view of the hole layout method for the simple bottom-pulling method for large-structure mining areas provided in this embodiment of the invention.

[0022] Figure 2 A diagram illustrating the blasting sequence for a simplified bottom-pulling method in a large-structure mining area, as provided in this embodiment of the invention.

[0023] Figure Labels

[0024] 1. Drilling chamber; 2. Bottom-pulling roadway; 31. First deep hole; 32. Second deep hole; 33. Third deep hole; 34. Fourth deep hole; 35. Fifth deep hole; 36. Sixth deep hole; 4. Trench platform; 5. Along-vein transport roadway; 6. Ore exit roadway; 71. First roof blasting zone; 72. Second roof blasting zone; 73. First side collapse blasting zone; 74. Second side collapse blasting zone. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] It should also be noted that, in order to avoid obscuring the present invention with unnecessary details, only the structures and / or processing steps closely related to the present invention are shown in the accompanying drawings, while other details that are not closely related to the present invention are omitted.

[0027] Additionally, it should be noted that the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0028] This invention provides a simple bottom-laying method for large-structure mining areas, comprising the following steps:

[0029] S1. According to the Livingston formula (USA) Calculate the rock drilling and blasting parameters, where L e Critical burial depth, which is the burial depth of the center of the explosive charge when only cracks or a small amount of fragmentation occur in the free rock surface, in meters; E is the strain energy coefficient, which is a constant for a specific rock and explosive; Q represents the weight of the spherical explosive charge, in kilograms; the optimal burial depth and explosive consumption are obtained by using single-hole blasting with gradually varying hole depth on the rock mass to be blasted, and the actual blasting parameters are obtained based on the calculated parameters.

[0030] S2. In the upper rock drilling chamber 1, according to the predicted ore body boundary line, construct the bottom-pull roadway 2 and several downward large-diameter deep holes according to the blasting parameters obtained in step S1. The bottom-pull length is the length of the mining area.

[0031] Specifically, the length of the mining area is 40-50m, and the length of the bottom roadway is 3-5m.

[0032] S3. Using spherical explosive charge intensive blasting technology and precision top-pressure blasting technology, the extension holes at the middle positions are blasted to pull the bottom. The bottom-pressure roadway 2 is used as a compensation space. The amount of explosive charge and the blasting range are determined according to the influence range of blasting vibration and the overall construction arrangement requirements. The number of blasting holes is determined according to the amount of explosive charge. Digital detonators are used to detonate in stages in the holes. The same method is used to carry out two top-pressure blasts.

[0033] Specifically, the number of extension holes for the large-diameter deep holes in the middle of the mining area is 15 to 25; the charging method is to charge 30 to 35 kg of explosives per hole, and fill the top of the explosive surface with 1.5 to 2 m of fine sand or rock cuttings; the height of the top blasting is 2 to 3 m.

[0034] S4. Use small lateral positioning blasting technology to blast the entire row or part of the continuous blast holes on both sides of the middle hole position. Use the space formed by the blasting of the middle row as the free compensation space. The height of the first lateral collapse blasting depends on the height of the middle row top blasting. The hole depth direction is formed by one or two blasts. Use the same method to laterally blast the blast holes corresponding to the entire row of positions of the outermost hole to form a complete and standardized trench bottom structure.

[0035] Specifically, the charging method for the small lateral positioning blasting technique is the same as in step S3, with a lateral blasting height ≤ 5m. All blasts are controlled below position 4 of the trench platform. The hole depth for each row and each hole is determined based on the slope of trench platform 4, with a hole deviation rate ≤ 1m. The angle of trench platform 4 is 40–50°, and the height of the bottom trench is 8–10m.

[0036] S5. The loader enters the bottom structure from the ore access road 6 via the ore transport roadway 5 to load and shovel out the ore.

[0037] The following describes the simple bottom-pulling method for large-structure mining areas provided by the present invention with reference to specific embodiments.

[0038] Example

[0039] This embodiment provides a simple bottom-laying method for large-structure mining areas, such as... Figures 1 to 2 As shown, it includes the following steps:

[0040] S1. According to the Livingston formula (USA) Calculate the rock drilling and blasting parameters, where L e Critical burial depth, the burial depth of the explosive charge center when only cracks or minor fragmentation occur in the free-faced rock, in meters (m); E is the strain energy coefficient, a constant for a specific rock and explosive; Q represents the weight of the spherical explosive charge, in kilograms (kg). The optimal burial depth and explosive consumption were determined through on-site single-hole blasting with gradually varying hole depths on the rock mass. Calculations showed that the basic parameters of this type of explosive under optimal conditions are: the optimal proportional volume is 0.408 m³. 3 / kg; the optimal proportional radius is 1.15m; the optimal proportional burial depth is 0.598m, and the actual blasting parameters are obtained based on the calculated parameters;

[0041] S2. In the upper rock drilling chamber 1, according to the predicted ore body boundary line, six rows of downward large-diameter deep holes are constructed according to the blasting parameters obtained from the test. The hole network parameters of the deep holes meet the density coefficient requirements of the bottom pulling part to a certain extent. The specifications of the bottom pulling roadway 2 are 5m, the stope length is 50m, and the bottom pulling length is the stope length.

[0042] S3. Employing spherical explosive charge intensive blasting technology and precision roof-pressure blasting technology, utilizing the bottom-pulling tunnel 2 as a compensation space, the extension holes in the middle two rows are detonated first, i.e. Figure 1The third deep hole 33 and the fourth deep hole 34 correspond to a row or part of continuous holes, approximately 20 holes in total, depending on the length of the stope. Each hole is loaded with about 30 kg of explosive (emulsion dynamite), and the top of the explosive is filled with 1.5 m of fine sand or rock cuttings. Digital detonators are used to detonate the explosives in stages, with the height of each top blast controlled at about 2.5 m. Figure 2 As shown, after first blasting the first top blasting zone 71, and then blasting the second top blasting zone 72 in the same way, the trench section reaches the trench platform position required by the design.

[0043] S4. Using the same charging method and small lateral positioning blasting technique, blast the entire row or part of the continuous blast holes corresponding to the second deep hole 32 and the fifth deep hole 35, such as... Figure 2 As shown in the first lateral collapse blasting zone 73, the space just formed by the blasting of the middle row is used as the free compensation space. The height of the first lateral collapse is determined based on the height of the middle row's top blast, and the maximum lateral collapse blasting height is determined to be 5m. Finally, the boreholes corresponding to the first deep hole 31 and the sixth deep hole 36 are blasted laterally using the same method, as shown in the figure. Figure 2 The second side-breach blasting zone 74 is shown in the diagram. The blasting of all three sections must be controlled below the designed overall trench platform 4. The depth of each hole in each row is formed according to the slope of the trench platform 4, and it must not be too deep. The hole deviation rate must be controlled within 1m, the smaller the better. Using this type of blasting technology and methods to precisely control the blasting can form a complete and standardized trench bottom structure, achieving efficient bottom-pulling construction. The bottom-pulling trench height is 8m, and the angle of the trench platform 4 is 45°, which can be adjusted appropriately according to the natural angle of repose of the ore.

[0044] S5. The loader enters the bottom structure from the ore access road 6 via the ore transport roadway 5 to load and shovel out the ore.

[0045] This invention, through the invention, field testing, and application of a simple bottom-pulling method for large-structure mining areas, has achieved better technical and economic results compared to previous manual bottom-pulling methods. It achieves the effects of simplicity, safety, efficiency, and low cost. Ultimately, the statistics show that the unit cost of mining for the bottom-pulling part of the entire mining area has been reduced by approximately 8.6 yuan / ton, and the construction time has been shortened by 25 days.

[0046] In summary, this invention extends the depth of the upper mining blast holes to the bottom structural platform of the trench. By employing intensive blasting technology with spherical explosive charges of variable cross-sectional sizes, precision top-pressure blasting technology, and deep-hole small lateral positioning blasting mining technology for the extended blast holes, a stable, standard, and usable new trench bottom structure is formed under the guarantee of precise blasting technology. This achieves safe and efficient bottom trenching, with a simple process, low construction difficulty, and high safety level.

[0047] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A simple bottom-laying method for large-structure stopes, characterized in that, Includes the following steps: S1. According to the Livingston formula (USA) Calculate the rock drilling and blasting parameters, where L e denoted as the critical burial depth, which is the burial depth of the center of the explosive charge when only cracks or a small amount of fragmentation occur in the free surface rock; E is the strain energy coefficient, which is a constant for a specific rock and explosive; Q represents the weight of the spherical explosive charge, in kg. The optimal burial depth and explosive consumption were determined through on-site single-hole blasting with gradually varying hole depths on the rock mass. Calculations showed that the basic parameters of the explosive under optimal conditions were: the optimal proportional volume is 0.408 m³. 3 / kg; the optimal proportional radius is 1.15m; the optimal proportional burial depth is 0.598m, and the actual blasting parameters are obtained based on the calculated parameters; S2. In the upper rock drilling chamber (1), according to the predicted ore body boundary line, six rows of downward large-diameter deep holes are constructed according to the blasting parameters obtained from the test. The hole network parameters of the deep holes meet the requirements of the bottom-pulling part density coefficient to a certain extent. The specifications of the bottom-pulling roadway (2) are 5m, the stope length is 50m, and the bottom-pulling length is the stope length. S3. Using spherical explosive charge intensive blasting technology and precise top pressure blasting technology, the bottom roadway (2) is used as a compensation space. The first to be detonated are the row or part of the continuous holes corresponding to the third deep hole (33) and the fourth deep hole (34). There are 20 holes according to the length of the mining area. Each hole is loaded with 30kg of explosives. 1.5m of fine sand or rock cuttings are filled above the explosive surface. Digital detonators are used to detonate the holes in stages. The height of the top pressure blasting is controlled at 2.5m. The first top pressure blasting zone (71) is blasted first, and then the second top pressure blasting zone (72) is blasted in the same way. The trench section has reached the trench platform position required by the design. S4. Using the same charging method and small lateral positioning blasting technique, blast the entire row or part of the continuous blast holes corresponding to the second deep hole (32) and the fifth deep hole (35), i.e., the first lateral collapse blasting zone (73). Use the space just formed by the blasting of the middle row as the free compensation space. The height of the first lateral collapse depends on the height of the blasting of the middle row top. The maximum lateral collapse blasting height is determined to reach 5m. Finally, use the same method to laterally blast the blast holes corresponding to the first deep hole (31) and the sixth deep hole (36), i.e., the second lateral collapse blasting zone. The blasting of the three parts is required to be controlled below the designed overall trench platform (4). The depth of each hole in each row is formed according to the slope of the trench platform (4). It must not be too deep. The deviation rate of the hole should be controlled within 1m, the smaller the better. By using the above blasting technology and means to accurately control the blasting, a complete and standardized trench bottom structure can be formed, and efficient bottom pulling construction can be achieved. The height of the bottom pulling trench is 8m, and the angle of the trench platform (4) is 45°. It can be adjusted appropriately according to the natural angle of repose of the ore. S5. The loader enters the bottom structure from the ore outlet roadway (6) via the ore transport roadway (5) to load and shovel out the ore.

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