Execution method of spaced explosive charge blasting in open-cut mines.

Abstract

This is a construction method of spaced explosive loading blasting in open-cut mines. [Solution] In this blasting method, in areas with low hardness coefficient rock, a combination of bottom-interval and middle-interval explosive loading is used. This increases the height of the lower charge column while simultaneously reducing the total amount of explosive charged in the hole, significantly reducing blasting costs while maintaining better blasting results. In areas with high hardness coefficient rock, a middle-interval explosive loading method is used, increasing the amount of explosive charged at the top of the blasthole axis, effectively reducing the occurrence of large blocks at the hole mouth and reducing the amount of secondary mechanical crushing work after blasting. The mutual cooperation between the various components of the middle-interval mechanism enhances the reflection and overlap of explosive shock waves, strengthening the stress field and extending the stress action time, thereby achieving a larger blasting impact. This ultimately improves blasting energy utilization, achieves more uniform rock crushing, and reduces the rate of large blocks after blasting.

Description

[Technical Field]

[0001] The present invention relates to the technical field of open-pit mine construction, and in particular to a method for interval charging blasting construction in open-pit mines. [Background technology]

[0002] In the deep-hole blasting process in open-cut mines, the explosive loading structure is an important factor that affects the blasting effect. A rational explosive loading structure can improve the uniformity of blasting blocks in blasting practice, and play a vital role in reducing blasting costs.

[0003] The geological conditions in the mining area are complex, with the parent rocks including dolomite, shale, claystone, and sandstone. The upper rock layers have been crushed into sandy, subangular, rounded, and breccia-like forms due to tectonic action. The middle and lower rock layers are relatively intact. As deep mining progresses, the rock layers above the base of the main ore body at the bottom of the mine are being separated. The demand for ore supply is gradually increasing, which in turn increases the volume of blasting and mining work, increasing the operating pressure of equipment and raising the requirements for blasting efficiency in on-site production. Furthermore, due to the diverse ore-rock endowment conditions and complex geological and rock strata, the consumption of blasting explosives remains high for a certain period of time, significantly increasing construction costs.

[0004] Therefore, there is a need to provide an improved technical solution to address the shortcomings of the prior art. Summary of the Invention [Problem to be solved by the invention]

[0005] SUMMARY OF THE INVENTION The object of the present invention is to provide a method for carrying out interval explosive charge blasting in an open-cut mine in order to solve at least the problems existing in the prior art. [Means for solving the problem]

[0006] In order to achieve the above object, the present application provides the following technical means: A method for interval explosive loading blasting (interval explosive loading) in an open-cut mine, Step 1 involves determining the geological conditions of the work area through surveying and exploration, and evaluating and determining the blasting parameters corresponding to the work area; Step 2 is to level the site (location) within the work area and create the construction conditions. Step 3: Designing corresponding blasting parameters according to the specific geological conditions of the working area. In the rock area with low hardness coefficient, a method of explosive loading that combines bottom interval explosive loading (charge) and middle interval explosive loading is adopted. In the rock area with high hardness coefficient, a method of middle interval explosive loading is adopted. In the blast hole, a middle interval mechanism is provided between the upper explosive segment and the lower explosive segment. The middle interval mechanism includes an upper cone located below the upper explosive segment and a lower cone located above the lower explosive segment, with the tips of the upper cone and the lower cone facing each other. A sleeve assembly including an inner tube and an outer tube is provided between the upper cone and the lower cone. A crushed stone layer and a foamed plastic layer are alternately filled between the inner tube and the outer tube. In the blast hole, a directional isolation tube is provided on the outer periphery of both the upper explosive segment and the lower explosive segment. Step 3: a directional isolation tube is provided, the body of the directional isolation tube has a corrugated structure, the outer periphery of the directional isolation tube is in close contact with the inner wall of the blast hole, and an explosive is loaded inside the directional isolation tube; Step 4 is positioning, drilling and maintaining holes within the work area based on the designed blasting parameters; Step 5 inspecting the drilled blast holes to ensure that the drilling meets design requirements; Step 6 includes loading explosives into the blast hole, connecting an explosive net, and blasting. The application method of spaced explosive charge blasting in open-cut mines. Beneficial effects

[0007] In this blasting method, in areas of rock with a low hardness coefficient, a combination of bottom-interval and middle-interval explosive loading is used to increase the height of the lower explosive column while simultaneously reducing the total amount of explosive charged in the hole, thereby maintaining a better blasting effect and significantly reducing blasting costs.In areas of rock with a high hardness coefficient, a middle-interval explosive loading method is used to increase the amount of explosive charged above the blasthole axis, effectively reducing the occurrence of large blocks at the hole mouth and reducing the amount of secondary mechanical crushing work after blasting.

[0008] In addition, the mutual cooperation between the components of the middle interval mechanism strengthens the reflection and superposition of the explosive shock wave, strengthens the stress field, and at the same time extends the stress action time, thereby achieving a larger blasting impact, ultimately improving the blasting energy utilization rate, making the rock breaking effect more uniform, and reducing the boulder yield after blasting. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a process flow diagram of a blasting construction method in one embodiment of the present invention. [Figure 2] FIG. 1 is a schematic diagram of explosive charging in a rock region with a low hardness modulus in one embodiment of the present invention. [Figure 3] FIG. 1 is a schematic diagram of explosive charging in a rock region with a high hardness modulus in one embodiment of the present invention. [Figure 4] FIG. 2 is a structural schematic diagram of a central spacing mechanism in one embodiment of the present invention. [Figure 5] 1 is a cross-sectional schematic view of a directional isolation barrel in one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] According to a specific embodiment of the present invention, as shown in FIGS. 1 to 5, the present invention provides a construction method for interval explosive charging blasting in an open-cut mine, which includes the following steps 1 to 6.

[0011] In step 1, the geological conditions of the work area are identified through surveying and exploration, and the blasting parameters corresponding to the work area are evaluated and determined. In this example, the geological conditions of the work area are identified, and rock lithology analysis is performed on the exploration samples to determine basic attributes such as rock hardness, structure, ore content grade, and oxidation rate. Rock-related data is detected and recorded, and the blasting parameters corresponding to blasting of the rock area are evaluated and determined. After the blasting area is divided, a safety barrier is constructed using existing stone and sediment on site, and the blasting area is fenced off to prevent unrelated vehicles and personnel from entering.

[0012] In step 2, the site within the work area is leveled to create construction conditions. In this example, obstacles on the site (such as residual harvesting, trees, and stone blocks) are removed so as not to affect the drilling work. If the site has large undulations or depressions, auxiliary equipment is used to level the drilling work surface so that the drilling machine can move stably within the work area. During drilling work, it is necessary to ensure that the work surface is solid and stable and that there are no soft or loose areas. If necessary, an excavator can be used to backfill the area in accordance with the auxiliary equipment. If the site is prone to water accumulation or is in an area where water collects, drainage work must be carried out in advance.

[0013] In step 3, the corresponding blasting parameters are designed based on the specific geological conditions of the working area, except that in the rock area with low hardness coefficient, the explosive loading method combining bottom interval explosive loading and middle interval explosive loading is adopted, and in the rock area with high hardness coefficient, the middle interval explosive loading method is adopted.

[0014] A middle spacing mechanism is provided between the upper explosive segment 2 and the lower explosive segment 1 in the blast hole, and the middle spacing mechanism includes an upper cone 5 located below the upper explosive segment 2 and a lower cone 4 located above the lower explosive segment 1, with the tip of the upper cone 5 and the tip of the lower cone 4 facing each other.

[0015] Between the upper cone 5 and the lower cone 4 is provided a sleeve assembly including an inner tube 6 and an outer tube 7, and between the inner tube 6 and the outer tube 7, layers of crushed stone 9 and foamed plastic 8 are alternately filled.

[0016] In this embodiment, a central spacing mechanism is provided, and the inner pipe 6 of the central spacing mechanism has a hollow structure, with the tip of the upper cone 5 and the tip of the lower cone 4 facing each other in the inner pipe 6. As a result, during blasting, the hollow inner pipe 6 serves as a conductor for the blasting gas, and the shock waves of the upper explosive segment 2 and the lower explosive segment 1 collide with each other within the inner pipe 6 of the central spacing mechanism. The crushed stone layers 9 and foamed plastic layers 8 alternately provided between the inner pipe 6 and the outer pipe 7, so that the foamed plastic layers 8 quickly collapse under the impact, and the adjacent crushed stone layers 9 impact each other, forming reflected waves and superimposed waves within the central spacing mechanism. The mutual cooperation of the crushed stone layers 9 and foam plastic layers 8, which are alternately arranged between the opposing cones, hollow inner tube 6, and outer tube 7 in the middle spacing mechanism, strengthens the reflection and superposition of the explosive shock waves, strengthens the stress field, and at the same time, extends the stress action time, thereby achieving a larger blasting impact, ultimately improving the blasting energy utilization rate, making the rock breaking effect more uniform, and reducing the rate of large blocks after blasting.

[0017] In this embodiment, the directional isolation tube 3 and the middle spacing mechanism are both made of plastic material, and the inner tube 6, outer tube 7, upper cone 5, and lower cone 4 are secured together by adhesive bonding. First, the inner tube 6 and outer tube 7 are secured to the lower cone 4, then layers of crushed stone 9 and foam plastic 8 are alternately filled between the inner tube 6 and outer tube 7, and finally the upper cone 5 is glued onto the inner tube 6 and outer tube 7. The assembled middle spacing mechanism is then lowered into the blast hole above the lower explosive segment 1. In another embodiment, some foam plastic can be pre-glued into the lower cone 4 so that the foam plastic in the lower cone 4 directly contacts the upper surface of the upper explosive segment 2 when the middle spacing mechanism is lowered into place.

[0018] In step 4, holes are positioned, drilled, and maintained within the work area based on the designed blasting parameters.

[0019] In this embodiment, holes are positioned rationally based on the determined mesh parameters, and the components for positioning the holes are easy to identify, which is advantageous for determining the hole positions during drilling operation. The mesh parameters can be adjusted according to the geological characteristics of the rock, such as its type, strength, structure, and the presence of slits and joints, as well as the blasting targets and safety requirements. After drilling is completed, an initial measurement is made of the depth of each blast hole. If the measurement is successful, the crushed stone and debris from the hole mouth are removed, and the blast hole is sealed and protected with a debris bag.

[0020] The hole diameter for interval explosive blasting in open-cut mines depends on the type of drilling machine, the step height, the rock properties, etc. In this example, the diameter of the drill holes is 250 mm, which is the main drilling mode applied to this work area. The blast holes are arranged in a triangular pattern.

[0021] In step 5, the drilled blast holes are inspected to ensure they meet the design requirements. In this example, after drilling with the drilling machine, the blast holes are first inspected. The hole depth and hole position errors are strictly controlled within ±0.2 m to ensure they meet the blasting design requirements. Rejected holes are marked for further processing. The day before blasting, all blast holes in the blasting area are re-inspected. When inspecting holes, the blasting design is strictly followed, the actual situation on site is accurately measured, and the work card is clearly completed. Rejected holes or blast holes with inappropriate depths are clearly marked with warning tape or other items to make them easy for the drilling machine operator to identify.

[0022] The handling and re-inspection of rejected holes are as follows: marking the rejected holes and arranging for operators to make up or re-drill holes; monitoring the hole depth, diameter and wall condition before blasting, taking measures to repair or adjust if any problems occur, and inspecting and maintaining the blasted holes.

[0023] The preparation of the fill material is as follows: Check that the fill material in the hole is sufficient and replenish as necessary.

[0024] In step 6, explosives are loaded into the blast hole, a detonation net is connected, and blasting is carried out.

[0025] This blasting method selects appropriate interval explosive loading methods and interval segment lengths according to different rock structures and rock mass characteristics. In rock areas with low hardness coefficients, a loading method that combines bottom and middle interval explosive loading can be used to increase the height of the lower charge column while reducing the total amount of explosive charged in the hole, maintaining better blasting effectiveness and significantly reducing blasting costs. In rock areas with high hardness coefficients, a middle interval explosive loading method can be used to increase the amount of explosive charged at the top of the blasthole axis, effectively reducing the occurrence of large blocks at the hole mouth and reducing the amount of secondary mechanical crushing work after blasting.

[0026] Based on the diameter of the blast hole, calculate the bottom burden according to the following formula: W1=nD [Where W1 is the bottom burden (m), D is the diameter of the blast hole (m), and n is a coefficient related to the inclination angle of the blast hole and rock hardness, and generally n = 20 to 45] Based on the diameter of the blast hole, the overdepth (subdrill) of the blast hole is calculated according to the following formula: h=(8-12)d 孔 [wherein h is the over depth (m) and d is the diameter of the drill hole (m)]

[0027] In this example, the n value in the bottom burden calculation formula for vertical blastholes is used as a small value when the rock hardness is high and as a large value when the rock hardness is low. The diameter of the interval explosive-charged blasthole in this work area is 250 mm, with D = 0.250. Based on the difference in rock hardness between Zone 2 and Zone 1 in this work area, the n value for Zone 2 is set to 40 and the n value for Zone 1 is set to 28. The calculation results are: bottom burden W1 = 10 for Zone 2 and bottom burden W1 = 7 for Zone 1.

[0028] Blasthole overdepth refers to the portion of the drilled hole that exceeds the base plate of the stairs. By increasing the amount of explosives at the bottom of the blasthole, the constraint effect of the base plate of the stairs can be overcome, and no foundation will be left at the bottom of the stairs after blasting. However, based on the rock nature of Zone 2 in this work area, the coefficient of the blasthole overdepth calculation formula is set to 8, and the calculated blasthole overdepth result is h = 2m.

[0029] Calculate the distance between blast holes according to the formula below: a=mW1 [where a is the distance between holes (m) and m is the density coefficient] Calculate the distance between rows of blast holes according to the formula below.

number

[0030] In this example, the m value in the hole distance calculation formula is usually in the range of 0.7 to 1.4, and based on field tests, it is set to 0.85. As a result of the calculation, when the diameter of the main blast hole is 250 mm, a is 7.14 m, so it is set to 7 m. When the diameter of the blast hole is 250 mm, b = 6.06, so it is set to 6 m.

[0031] Mesh parameters can be adjusted based on factors such as the rock type, weathering conditions, and explosive charge structure of the blasting area. When using mid-spacing explosives, the mesh parameters for the 8-m segment of the ore area in Zone 1 are typically adjusted from 6x7 to 6x6, with the blasthole overdepth adjusted to 1-1.5 m. When using both bottom-spacing and mid-spacing explosives, the mesh parameters for the 15-m segment of the rock area in Zone 2 are typically adjusted from 8x10 to 7x9, with the blasthole overdepth adjusted from 2 m to 1 m due to the lower rock hardness coefficient.

[0032] In the case of blasting multiple rows of holes, calculate the explosive charge for each hole in the main blast hole according to the following formula: Q=KqabH [In the formula, K is the coefficient of increase that takes into account the mineral rock resistance of each preceding row of holes, and is generally 1.1 to 1.2, and q is the unit explosive consumption (kg / m 3 ), where a is the distance between holes (m), b is the distance between rows (m), and H is the step height (m).

[0033] In this example, it is determined based on the rock blastability, explosive type, free surface condition, detonation method, and block requirements, combined with the test blasting situation. In this working area, when the rock solidity coefficient f is 6 to 8, the unit explosive consumption q value is 0.48 to 0.52 kg / m 3 is.

[0034] In this work area, the bedrock is mainly moderately weathered dolomite, and the strength explosive loading for loosening blasting is set at 0.38 kg / m based on experience. 3This results in a single-hole explosive charge Q of 359.1 kg, and for convenience of explosive loading, the single-hole charge is set to 360 kg.

[0035] When interval explosive loading is used, explosives are loaded at the position where the staircase blasting resistance is the greatest, and the part of the hole where explosives are not loaded is selected to be a position with a small burden (resistance line) or a position where the blasting gas can easily dissipate along the slit. When the staircase height is 15m or less, the interval explosive loading is divided into two segments of explosive loading, and the number of interval segments is increased when the total length of the interval segments exceeds 4m.

[0036] In this example, the presence of spacing segments reduces the initial pressure exerted by the detonation on the borehole wall, reduces over-fragmentation, distributes blasting energy evenly throughout the borehole, extends the blasting duration, and increases the blasting impact force. If the spacing segment length exceeds 4 m, the number of spacing segments can be increased. If the rock is highly blastable, the spacing segment length can be increased, and spacers or filler material can be used to separate the two segments. The portion of the borehole where no explosives are to be loaded should be located closest to the step slope, i.e., in a location with minimal burden, so that the spacing explosives can achieve the best possible blasting effect.

[0037] The explosive charge at the top of the hole is designed to be 17-35% of the total explosive charge, and the total length of the spacing segments is 32-42% of the total charge length in rock areas with low hardness coefficient, and the total length of the spacing segments is 15-32% of the total charge length in rock areas with high hardness coefficient.

[0038] In this example, taking the mine area with a high hardness coefficient in this work area as an example, when using the middle interval explosive loading method, the hole depth and over-depth are combined to 9m, the blasthole bottom explosive loading is designed to be 3m, and the top explosive loading is designed to be 0.8m, with the top explosive loading accounting for approximately 21% of the total explosive loading. Crushed stone with a particle size of less than 3cm is placed between the upper and lower explosive pillars at intervals of 1.2m, the interval segment length is 31.6% of the total explosive pillar length, and the top filling is designed to be 4m.

[0039] In the rock area with low hardness coefficient, a combined bottom spacing explosive loading and middle spacing explosive loading method is adopted, the total hole depth and over depth is 16m, the bottom spacer spacing height is designed to be 1.2m, the bottom explosive loading is 5.3m, and the top explosive loading is 2.5m, with the top explosive loading accounting for approximately 32% of the total explosive loading. Between the upper and lower explosive pillars, drilling waste is placed at 2m intervals, the total spacing segment length is 41% of the total pillar length, and the top filling is designed to be 5m.

[0040] In the detonation net, the minute interval time between holes is calculated according to the following formula.

number

[0041] In this example, based on the geological conditions of the work area, Q is 140 to 480 kg, r e is 0.95 to 1.28 g / cm 3 , r r is 2.65g / cm 3 , D is 2500 to 4800 m / s, Cr is 5000 m / s, S is 10 mm, and V is 2 to 5 mm / ms. By substituting these data into the hole-to-hole interval time calculation formula, the hole-to-hole interval time is in the range of 15 to 75 ms. Taking into account existing explosives, in this example, detonators of 17 ms, 25 ms, and 42 ms are actually selected.

[0042] In the detonation network, the inter-row minute difference interval time is calculated according to the following formula.

number

[0043] In this example, based on the geological conditions of the work area, S0 is set to 4 to 7 m, V2 to 20 to 25 m, V1 to 15 to 20 m, and H0 to 2 to 3 m. By substituting these data into the inter-row differential interval time calculation formula, the inter-row differential interval time is set to a range of 40 to 147 ms. Combining existing explosive materials, in this example, 42 ms and 75 ms are selected.

[0044] In this example, low-segment external detonators and high-segment internal detonators are designed to prevent shock waves, seismic waves, and flying rocks from the previous blast hole from destroying the subsequent blast hole network. Based on the experience of this mine's hole-by-hole blasting, a 500ms high-precision internal detonator is selected for this work area in hard rocks 7 to 15 meters deep, which can meet the safety design requirements for the surface network in hole-by-hole blasting technology.

[0045] In this embodiment, the blast holes in this work area adopt a backward tilt connection method, so that the front blast holes can create many free surfaces for the rear blast holes, while keeping the isochrones uniform, and the throwing direction can achieve the expected effect.

[0046] In rock areas with low hardness coefficients, the blasthole comprises, from bottom to top, a bottom spacer, a lower explosive segment 1, a middle spacing mechanism, an upper explosive segment 2, and a filler, where both the upper explosive segment 2 and the upper explosive segment 2 use amphoteric explosive (ammonium nitrate oil explosive). In this embodiment, the bottom spacer leaves a space at the bottom of the blasthole, which allows the peak pressure to drop rapidly after the upper explosive blasting, and the bottom spacing space is not directly affected by the explosive energy. This reduces the extent of the fracture area caused by the explosive blasting action, and avoids a rapid attenuation of the blasting energy.

[0047] In the rock area with a high hardness coefficient, the blasthole comprises, from bottom to top, a lower explosive segment 1, a middle spacing mechanism, an upper explosive segment 2, and a filler, where both the upper explosive segment 2 and the upper explosive segment 2 use emulsion explosives. In this embodiment, the middle spacing mechanism allows the surrounding rock to be subjected to the combined action of the upper and lower explosive pillars, and the two relative shock wave fronts overlap each other, resulting in a more uniform rock fragmentation effect and a reduced rate of large blocks after blasting.

[0048] In this embodiment, as shown in Figures 4 and 5, in the blast hole, directional isolation tubes 3 are provided on the outer periphery of both the upper explosive segment 2 and the lower explosive segment 1, the body of the directional isolation tube 3 has a corrugated structure, the outer periphery of the directional isolation tube 3 is tightly attached to the inner wall of the blast hole, and explosives are loaded inside the directional isolation tube 3.

[0049] However, the directional isolation tube 3 is installed around the outer periphery of the explosive segment, and the directional isolation tube 3 serves to isolate the explosive from the inner wall of the blast hole, leaving a gap between the explosive and the inner wall of the blast hole, achieving the effect of non-bonded explosive loading. At the same time, the cross-sectional shape of the directional isolation tube 3 is a uniform corrugated structure, which has the effect of uniformly directional blasting around the blast hole, and plays a role in reducing the rate of large blocks after blasting. [Explanation of symbols]

[0050] 1 Lower explosive segment 2 upper explosive segment 3 Directional isolation tube 4 Lower Cone 5 Upper cone 6 Inner tube 7 Outer tube 8 foam plastic layers 9 Crushed Stone Layer

Claims

1. A method for interval explosive loading blasting in an open-cut mine, comprising: Step 1 involves determining the geological conditions of the work area through surveying and exploration, and evaluating and determining the blasting parameters corresponding to the work area; Step 2 is to level the site within the work area and create the construction conditions. Step 3: Designing corresponding blasting parameters based on the specific geological conditions of the working area, in which a method of explosive loading that combines bottom interval explosive loading and middle interval explosive loading is adopted in the rock area with low hardness coefficient, and a method of middle interval explosive loading is adopted in the rock area with high hardness coefficient, where a middle interval mechanism is provided between the upper explosive segment and the lower explosive segment in the blast hole, and the middle interval mechanism includes an upper cone located below the upper explosive segment and a lower cone located above the lower explosive segment. Step 3: the blast hole includes a lower cone, the tip of the upper cone and the tip of the lower cone are arranged opposite to each other, a sleeve assembly including an inner tube and an outer tube is arranged between the upper cone and the lower cone, and crushed stone layers and foamed plastic layers are alternately filled between the inner tube and the outer tube, and in the blast hole, directional isolation tubes are arranged on the outer periphery of both the upper explosive segment and the lower explosive segment, the body of the directional isolation tube has a corrugated structure, the outer periphery of the directional isolation tube is tightly attached to the inner wall of the blast hole, and the inside of the directional isolation tube is filled with explosives; Step 4: positioning, drilling, and maintaining holes within the work area based on the designed blasting parameters; Step 5 inspecting the drilled blast holes to ensure that the drilling meets design requirements; Step 6 involves loading explosives into the blast holes, connecting the detonation net, and detonating the explosives. A method for carrying out interval explosive loading blasting in an open-cut mine, comprising:

2. Based on the diameter of the blast hole, calculate the bottom burden according to the following formula: W １ =nD [wherein, W １ is the bottom burden (m), D is the diameter of the blast hole (m), and n is a coefficient related to the dip angle of the blast hole and rock hardness. And calculate the over-depth of the blast hole according to the following formula based on the diameter of the blast hole: h=(8-12)d 孔 [wherein h is the over-depth (m), and d 孔 is the diameter of the borehole (m)] 2. The method for carrying out interval explosive loading blasting in an open-cut mine according to claim 1.

3. Calculate the distance between blast holes according to the formula below: a=mW １ [wherein a is the distance between holes (m) and m is the density coefficient] Calculate the distance between rows of blast holes according to the formula below: [Equation 1] [wherein b is the distance between rows (m) and a is the distance between holes (m)] 3. A method for carrying out interval explosive loading blasting in an open-cut mine according to claim 2.

4. In the case of blasting multiple rows of holes, calculate the explosive charge for each hole in the main blast hole according to the following formula: Q = KqabH [where K is the increase coefficient taking into account the mineral rock resistance of each preceding row of holes, and q is the unit explosive consumption (kg / m ３ ), where a is the distance between holes (m), b is the distance between rows (m), and H is the step height (m).

4. A method for carrying out interval explosive loading blasting in an open-cut mine according to claim 3.

5. When interval explosive loading is adopted, explosives should be loaded in accordance with the position where the blasting resistance of the step is the greatest, and the part of the hole where explosives are not loaded should be selected as a position with a small burden or a position where the blasting gas can easily dissipate along the slit. The construction method for interval explosive loading blasting in an open-cut mine as described in claim 1, characterized in that under the condition that the stair height is 15m or less, the interval explosive loading is divided into two segments of explosive loading, and the number of interval segments is increased when the total length of the interval segments exceeds 4m.

6. The explosive charge at the top of the hole is designed to be 17-35% of the total explosive charge. The total length of the spacing segments is 32-42% of the total length of the pillar in the low hardness rock region; The method for carrying out interval explosive loading blasting in an open-cut mine as described in claim 5, characterized in that the total length of the interval segments is 15 to 32% of the total charge pillar length in rock areas with high hardness coefficients.

7. In the detonation network, the interval time between holes is calculated according to the following formula: [Equation 2] [where t is the inter-hole gap time (ms), Q is the average explosive charge in the blasthole (kg), and r ｅ is the explosive (g / cm ３ ) and r ｒ is the volumetric mass of the rock (g / cm ３ ), D is the detonation velocity of the explosive in the hole (m / s), Cr is the longitudinal wave velocity of the rock (m / s), S is the rock movement distance (mm), and V is the average movement speed of the rock mass (mm / ms)].

4. A method for carrying out interval explosive loading blasting in an open-cut mine according to claim 3.

8. In the detonation network, the inter-row differential interval time is calculated according to the following formula: [Equation 3] [wherein, t ０ is the inter-column differential interval time (ms), and S ０ is the distance between the front and rear rows (m), and V ２ is the flight speed of the central rock mass (m / s), and V １ is the flight speed of the blocking segment (m / s), and H ０ is the drop height (m)] 8. A method for carrying out interval explosive loading blasting in an open-cut mine according to claim 7.

9. In the rock area with low hardness coefficient, the blasthole includes, from bottom to top, a bottom spacer, a lower explosive segment, a middle spacing mechanism, an upper explosive segment, and a filler, wherein the upper explosive segment and the upper explosive segment both adopt amphoteric explosive; The construction method of interval explosive loading blasting in open-cut mines according to any one of claims 1 to 8, characterized in that in the rock area with high hardness coefficient, the blast hole comprises, from bottom to top, a lower explosive segment, a middle interval mechanism, an upper explosive segment, and a filler, with the proviso that the upper explosive segment and the upper explosive segment both adopt emulsion explosive.

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