Blasting method for half-bottom ore receiving structure of gently inclined-inclined ore body

Abstract

The invention discloses a blasting method for a half-bottom ore receiving structure of a gently inclined-inclined ore body, and belongs to the technical field of underground mining. The method comprises the following steps: 1, collecting related information of an ore body, and determining geological conditions, an ore body inclination angle and a stope arrangement mode of the ore body; 2, establishing a geometric model of the chamber according to the data collected in the step 1; 3, according to the data collected in the step 1, the throwing distance, explosive unit consumption and throwing angle of throwing blasting are determined; and 4, according to calculation results of the step 2 and the step 3, a half-bottom ore receiving structure is constructed, throwing blasting is carried out on one side of the gently inclined-inclined ore body, and loosening blasting is carried out on the other side of the gently inclined-inclined ore body. The method can greatly increase the height of the stope room and increase the mining strength of the stope, and is suitable for gently inclined-inclined ore bodies with any thickness.

Description

Technical Field

[0001] The invention belongs to the technical field of underground mining, and more specifically, relates to a blasting method for a semi-bottom ore receiving structure of a gently inclined-inclined ore body. Background Art

[0002] Loosening blasting and throwing blasting are two common forms of rock crushing in open-pit mining and geotechnical engineering. Loosening blasting can crush rocks in situ, while throwing blasting will scatter them in a designated space while crushing them. Existing underground mining projects usually use loosening blasting technology to control the crushing of ore rocks in the original loose space and limit the scattering of ore rocks.

[0003] From the perspective of underground mining, the mining of gently inclined and inclined ore bodies with an inclination of 15° to 50° is a common technical problem in underground mining. The traditional mining process based on loosening blasting and complete ore-bearing structure has the problems of "three lows and two highs", namely, low mine room height, recovery rate, and stope strength, and high depletion rate and excavation ratio. The throwing blasting technology also has occasional industrial application cases, but this technology is only used in the treatment of gently inclined thin ore bodies and goafs, and the technical system is not yet perfect.

[0004] For example, the Chinese patent application number is CN201710540541.7, and the publication date is September 15, 2017, which discloses an oblique throwing blasting mining method for gently inclined thin ore bodies. Although this scheme adopts two controlled blasting methods, oblique pre-splitting blasting plus throwing blasting, which reduces dilution and loss, it is only applicable to the application scenario of directional throwing blasting of gently inclined thin ore bodies, and there is a lack of design numerical models for technical parameters such as mine room height, throwing distance, throwing angle, and throwing explosive unit consumption, which limits the promotion and application of this technology.

[0005] Another example is the Chinese patent application number: CN202110905758.X, the publication date: November 9, 2021, which discloses a method for blasting shallow goaf in open-pit mines, which belongs to the field of engineering blasting technology. Although this scheme adopts two blasting methods, loosening blasting and throwing blasting, it is a loosening blasting of the goaf roof and a throwing blasting of the goaf side, which is only applicable to the application scenario of loosening blasting plus throwing blasting of the goaf, and cannot be applied to the semi-bottom ore structure of the gently inclined-inclined ore body with a certain inclination angle. Summary of the invention

[0006] 1. Problems to be solved

[0007] Aiming at the problem that there is no perfect blasting method in the prior art for mining of gently inclined-inclined ore bodies with an inclination angle of 15° to 50°, the present invention provides a blasting method for the semi-bottom supporting structure of a gently inclined-inclined ore body, which can greatly increase the height of the mine room, expand the mining intensity of the stope, and is suitable for gently inclined-inclined ore bodies of any thickness.

[0008] 2. Technical solution

[0009] To solve the above problems, the present invention adopts the following technical solutions.

[0010] A blasting method for a semi-bottom ore structure of a gently inclined-inclined ore body comprises the following steps:

[0011] 1. Collect relevant data on the ore body and determine the geological conditions, inclination and layout of the ore body;

[0012] 2. Build a geometric model of the mine room based on the data collected in step 1;

[0013] 3. According to the data collected in step 1, determine the throwing distance, explosive consumption and throwing angle of throwing blasting;

[0014] Fourth, based on the calculation results of steps two and three, a semi-bottom receiving structure is constructed, and cast blasting is carried out on one side of the gently inclined-inclined ore body and loosening blasting is carried out on the other side.

[0015] As a further improvement of the technical solution, a geometric model of the mine chamber is established, including determining the height of the mine chamber and the positioning of the semi-bottom receiving structure.

[0016] As a further improvement of the technical solution, the mine room height is determined according to the following formula:

[0017] H≤L max .tanθ+h min ;

[0018]

[0019] Where H is the height of the mine room (m), θ is the inclination of the ore body (°), B is the horizontal thickness of the ore body (m), and L max is the set maximum economic throw distance (m), h min is the minimum hole depth of the set throwing blasting (h min =1.5~2.0m), P0 is the set waste rock mixing rate (%), γ 矿 is the specific gravity of ore (t / m 3 ), γ 废 is the specific gravity of waste rock (t / m 3 ), R 矿 is the unit ore revenue (yuan / t), γ 废 It is the unit waste rock profit and loss (Yuan / t).

[0020] As a further improvement of the technical solution, the semi-bottom receiving structure is based on the bottom structure of the loose blasting partition of the stope, and also serves as the receiving space of the throwing blasting partition. Its positioning is expressed by the offset distance between the center line of the cutting groove and the marginal line of the lower plate ore body, which is determined according to the following formula:

[0021] When the bottom is a flat structure,

[0022] When the bottom is a trench structure,

[0023] Among them, x is the offset distance (m), b is the cutting groove width (m), 8B1 is the mine room width (m), β1 is the side hole angle of the upward fan-shaped blasthole (°), and k2 is the centering coefficient of the trench in the mine room width direction (k2=1~1.7, 1 when centered).

[0024] As a further improvement of the technical solution, the throwing distance of the throwing blasting is determined according to the following formula:

[0025] L i ≤(HH i )·tanθ;

[0026] Among them, L i is the throwing distance of each row of blastholes (m), H i is the vertical depth of the blasthole (m).

[0027] As a further improvement of the technical solution, the explosive consumption per unit of throwing blasting is determined according to the following formula:

[0028] 0.9≤q1≤1.6kg / m 3 ;

[0029]

[0030]

[0031] Where g is the acceleration due to gravity (9.8 m / s 2 ), β is the throwing angle of the blasting (°), Q is the unit effective energy of the explosive type used (kJ / kg), M is the unit ore mass (M = 1000γ·1m 3 , kg), q1 is the unit consumption of explosives for loosening blasting of ore and rock (1.0~2.0kg / m 3 ), q2 is the unit consumption of explosives for rock displacement (kg / m 3 ), q n Unit consumption of explosives for rock throwing blasting (kg / m 3 ).

[0032] As a further improvement of the technical solution, when upward throwing blasting is performed, the throwing angle of the throwing blasting is determined according to the following formula:

[0033]

[0034] Where, h is the design height (m);

[0035] When performing downward throw blasting, the throw angle of the blast hole in the last blasting sequence of throw blasting is determined according to the following formula:

[0036] β = -θ.

[0037] As a further improvement of the technical solution, the pitch angle is not greater than 23.45°.

[0038] As a further improvement of the technical solution, during mining, the mine room close to the upper wall of the ore body is arranged perpendicular to the direction of the ore body, the width of the cutting groove is consistent with the width of the mine room, and the direction of the minimum resistance line of the blasthole points to the goaf area of ​​the cutting groove.

[0039] As a further improvement of the technical solution, the pre-splitting blasting technology is adopted, and the side holes of the blasthole array are arranged in an arc shape.

[0040] 3. Beneficial effects

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] (1) The present invention discloses a blasting method for a semi-bottom receiving structure of a gently inclined-inclined ore body. For a gently inclined-inclined ore body with an inclination angle of 15 to 50 degrees, a blasting technology with directional throwing on one side and loosening on the other side is designed, and a series of data models of design parameters such as mine room height, throwing distance, throwing angle, and bomb unit consumption are established, which provides sufficient data quantification support for the mining project, solves the problems of large amount of mining waste rock and scattered ore logistics in the prior art for the receiving structure of a gently inclined-inclined ore body, and greatly increases the mine room height and expands the mining intensity of the stope;

[0043] (2) The blasting method of the semi-bottom ore structure of a gently inclined-inclined ore body of the present invention can effectively improve the economic and technical indicators of the mining site, and achieve the optimization goals of a mine room height of 15 to 75 m, a mine room production capacity of 460 to 1450 t / d, a mine room recovery rate of 84.9 to 96%, a depletion rate of 0.1 to 1.73%, and a mining ratio of 1.69 to 8.31 m / kt. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a schematic diagram of the geometric model structure of the mine room of the present invention. DETAILED DESCRIPTION

[0045] Exemplary embodiments of the present invention are described in detail below. Although these exemplary embodiments are described in sufficient detail to enable those skilled in the art to implement the present invention, it should be understood that other embodiments may be implemented and various changes may be made to the present invention without departing from the spirit and scope of the present invention. The more detailed description of the embodiments of the present invention below is not intended to limit the scope of the claimed invention, but is merely for illustration and does not limit the description of the features and characteristics of the present invention, in order to propose the best mode for performing the present invention, and is sufficient to enable those skilled in the art to implement the present invention. Therefore, the scope of the present invention is limited only by the appended claims.

[0046] Example 1

[0047] A blasting method for the semi-bottom receiving structure of a gently inclined-inclined ore body is applicable to the underground mining process of a gently inclined-inclined ore body of any thickness with an ore body inclination angle of 15° to 50°. At the same time, the method is applicable to underground mining sites with engineering geology of a maximum allowable exposure area greater than 300 square meters and medium hydrogeological conditions, but not to underground mining sites with complex geological conditions such as heavy water and soft fractures. The throwing distance of the receiving body in the throwing blasting zone of the blasting method generally ranges from 5 to 60 meters. When the throwing distance exceeds 60 meters, the unit consumption of explosives is too high, and the process cost performance is sharply reduced.

[0048] In terms of the selection of mining methods, this blasting method is mainly applicable to mining methods such as segmented empty field followed by filling, staged empty field followed by filling, segmented rock drilling and staged mining empty field followed by filling, and empty field method. When the second step of the filling method is applied, technical measures to protect the filling body need to be supplemented.

[0049] In the selection of stope layout, for thick ore bodies, that is, when the horizontal thickness of the ore body is greater than the maximum width of a mine room, a vertical stope layout should be adopted. For narrow ore bodies, that is, when the horizontal thickness of the ore body is less than the maximum width of a mine room, a vertical stope layout should be adopted for gently inclined ore bodies with an inclination of 15° to 30°, and a stope layout along the strike should be adopted for inclined ore bodies with an inclination of 30° to 50°.

[0050] The blasting method mainly involves the construction of a semi-bottom ore receiving structure and the determination of technical parameters such as the mine room height, throwing distance, throwing angle, and throwing explosive unit consumption of the throwing blasting zone, including the following steps:

[0051] 1. Collect relevant data on the ore body and determine the geological conditions, inclination and layout of the ore body;

[0052] 2. Build a geometric model of the mine room based on the data collected in step 1;

[0053] 3. According to the data collected in step 1, determine the throwing distance, explosive consumption and throwing angle of throwing blasting;

[0054] Fourth, based on the calculation results of steps two and three, a semi-bottom receiving structure is constructed, and cast blasting is carried out on one side of the gently inclined-inclined ore body and loosening blasting is carried out on the other side.

[0055] Among them, Figure 1 As shown in the figure, the geometric model of the mine room is established, including the determination of the mine room height and the location of the semi-bottom ore-bearing structure. Since the mine room height is related to the horizontal thickness, inclination and maximum throw of the ore body, and from the perspective of economic rationality, the mine room height is also related to the waste rock mixing rate (depletion rate) and ore loss rate (recovery rate), and when the ore loss amount of the bottom structure triangular pillar is regarded as quantitative, the mine room height is only related to the waste rock mixing rate, the economic value of the ore and the waste rock disposal cost. Therefore, the mine room height is determined according to the following formula:

[0056] H≤L max .tanθ+h min ;

[0057]

[0058] Where H is the height of the mine room (m), θ is the inclination of the ore body (°), B is the horizontal thickness of the ore body (m), and L max is the set maximum economic throw distance (m), h min is the minimum hole depth of the set throwing blasting (h min =1.5~2.0m), P0 is the set waste rock mixing rate (%), γ 矿 is the specific gravity of ore (t / m 3 ), γ 废 is the specific gravity of waste rock (t / m 3 ), R 矿 is the unit ore revenue (yuan / t), γ 废 It is the unit waste rock profit and loss (Yuan / t).

[0059] The semi-bottom receiving structure is based on the bottom structure of the loose blasting partition of the stope, and also serves as the receiving space of the throwing blasting partition. The positioning of the semi-bottom receiving structure is expressed by the offset distance between the center line of the cutting groove and the marginal line of the lower plate ore body, which is determined according to the following formula:

[0060] When the bottom is a flat structure,

[0061] When the bottom is a trench structure,

[0062] Among them, x is the offset distance (m), b is the cutting groove width (m), 8B1 is the mine room width (m), β1 is the side hole angle of the upward fan-shaped blasthole (°), and k2 is the centering coefficient of the trench in the mine room width direction (k2=1~1.7, the k2 value is the distance between the trench and the farthest end in the mine room width direction divided by half the mine room width, and it is 1 when centered).

[0063] The throwing distance of each row of blastholes is calculated based on the vertical depth of the blastholes and the inclination of the ore body, and is combined into one design unit at a step distance of 15 to 20 m. The design steps are simplified and the throwing distance of the blasting is determined according to the following formula:

[0064] L i ≤(HH i )·tanθ;

[0065] Among them, L i is the throwing distance of each row of blastholes (m), H i is the vertical depth of the blasthole (m).

[0066] A large amount of explosives is one of the necessary conditions for throw blasting. The required explosives consumption is mainly composed of two parts: the explosives consumption for loosening blasting and the explosives consumption for shifting blasting. The explosives consumption for throw blasting is determined according to the following formula:

[0067] 0.9≤q1≤1.6kg / m 3 ;

[0068]

[0069] Where g is the acceleration due to gravity (9.8 m / s 2 ), β is the throwing angle of the blasting (°), Q is the unit effective energy of the explosive type used (kJ / kg), M is the unit ore mass (M = 1000γ·1m 3 , kg), q1 is the unit consumption of explosives for loosening blasting of ore and rock (1.0~2.0kg / m 3 ), q2 is the unit consumption of explosives for rock displacement (kg / m 3 ), q n Unit consumption of explosives for rock throwing blasting (kg / m 3 ).

[0070] Taking iron ore as an example, at γ = 3.8t / m 3 , β=0°, 2# rock ammonium nitrate explosive, Q=3512kJ / kg, q1=1.25kg / m 3 Under the condition of i =10~60m n =1.303~1.568kg / m 3 .

[0071] The unit consumption of explosives for throw blasting is about 1.05 to 1.26 times that of loosening blasting. Increasing the throw angle can reduce the unit consumption of explosives for throw blasting.

[0072] The throwing angle of underground blasting is limited by space, and the maximum throwing height of the upper explosive body must not be greater than the height of the rock drilling chamber (about 4m).

[0073] When performing upward throwing blasting, the throwing angle of the throwing blasting is determined according to the following formula:

[0074]

[0075] Where h is the design height (m). i When ≤60m and h≤4m, β≤23.45°, so the maximum throw angle of underground free throw blasting should not be greater than 23.45°.

[0076] When performing downward throw blasting, the throw angle of the blast hole in the last blasting sequence of throw blasting is determined according to the following formula:

[0077] β = -θ.

[0078] In addition, when performing throw blasting, the process can be adjusted and controlled in the following ways to improve the blasting effect.

[0079] ①Throwing direction control technology

[0080] In the throwing blasting technology, the blasted body mainly falls along the direction of the line of least resistance. When mining in an inclined ore body underground, the project object of the throwing blasting is the upper ore body, and the throwing location is the goaf area mined in advance near the cutting groove.

[0081] Specifically, the layout of the mine room near the upper plate of the ore body needs to be perpendicular to the direction of the ore body; the width of the cutting groove should be consistent with the width of the mine room; the direction of the minimum resistance line of the blasthole should point to the goaf area of ​​the cutting groove.

[0082] ②Throwing distance control technology

[0083] When the density of the blasted body and the unit effective energy of the explosive type used are constant, the throwing distance is only related to the unit consumption of the ore-rock displacement explosives and the throwing angle. The unit consumption of the ore-rock displacement explosives and the throwing angle of the throwing blasting are adjusted by designing the blasting parameters to control the throwing distance required for the project.

[0084] Specifically include: under the condition that the accuracy of the perforating drill permits, it is preferred to increase the throw angle to increase the throw distance in order to reduce the consumption of explosives, but the throw angle should not be greater than 23.45°. Too large a throw angle will cause the explosive body to rebound and affect the density of the explosive pile; increase the throw distance by increasing the consumption of explosives so that the explosive body falls into the receiving mineral structure after being thrown, such as reducing the blasthole density coefficient, increasing the charge structure coefficient, reducing the row spacing, increasing the blasthole diameter, etc.; increasing the energy of explosives can also increase the throw distance.

[0085] ③ Blasting fragmentation control technology

[0086] The main indicators for measuring blasting fragmentation are the large-block output rate and the fine-broken ore and rock output rate, which are mainly related to the structural surface development degree and the blasting structure parameters. The reasonable values ​​are generally between 75×75×75mm and 500×500×500mm. The large-block output rate should be ≤5%, and the fine-broken ore and rock output rate should be ≤20%.

[0087] Specifically, it includes: increasing the unit consumption of explosives to reduce the rate of large pieces; when the unit consumption of explosives is constant, reducing the diameter of the blasthole and increasing the number of blastholes per unit volume to make the explosive energy distribution more uniform and reduce the rate of large pieces; when the unit consumption of explosives is constant, reducing the micro-difference of blasting of adjacent blastholes to further add up the blasting energy and reduce the rate of large pieces; measures to reduce the output rate of finely crushed ore and rock are opposite to the technical measures to reduce the rate of large pieces.

[0088] ④ Explosion pile density control technology

[0089] The density of the blast pile refers to the percentage of the explosive body thrown to a specified location, generally the goaf near the cutting groove.

[0090] Specifically include: blasting the cutting groove and the ore body on the upper plate outside the groove in advance, and unloading a large amount of ore to expand the space of the ore-bearing structure; making the direction of the blasting funnel of the blasting hole point to the cutting groove as much as possible; the blast hole throwing angle should not be downward, the downward tilt of the blast hole will cause the ore and rock to scatter before reaching the predetermined goaf; the blast hole throwing angle should not be greater than 23.45°, too large an angle will cause the ore and rock to collide with the roof of the goaf and rebound and scatter.

[0091] ⑤ Two-step backfilling method to protect backfill body

[0092] During the second step of the throwing blasting process of the filling method, the two sides of the mining space are exposed filling bodies, which are frequently impacted by the scattered ore and rock, and necessary protective measures need to be taken.

[0093] Specifically, it includes: using pre-splitting blasting technology to reduce the damage of blasting energy to the filling body; arranging the side holes of the blasthole array into an arc shape, appropriately changing the throwing direction, and reducing the impact and damage of scattered ore and rock on the filling bodies on both sides; increasing the production capacity of the mining area and shortening the exposure time of the filling body; appropriately increasing the strength of the filling body and improving the stability of the filling body.

[0094] The following is a further detailed description of the results of calculation and actual construction based on the above method.

[0095] There are 8 mining areas in a certain area, located at the flank ends of thick ore bodies, with production and mining areas gently inclined to inclined, with an inclination angle of θ=30°~44°.

[0096] The design parameters of the mine room structure are: total length L = 65m, total height H = 32m, width B = 18m.

[0097] The blasting design parameters are: fan-shaped holes in the upward loosening blasting area φ80mm, row spacing 2.0m, and explosive unit consumption q1=1.15kg / m 3 ; Downward throwing blasting area fan-shaped hole φ120mm, row spacing 3.0m, throwing angle β=0~5°, explosive unit consumption q n =1.3~1.5kg / m 3 .

[0098] The design parameters of the semi-bottom receiving structure are: only the receiving structures such as trenches and oblique crossings are set up in the vein at the bottom of the mine room, and there are no receiving structures outside the vein; the cutting groove is located in the ore-rock contact zone of the lower horizontal ore body, the length, width and height of the cutting groove = 18m×5m×32m, and the length, width and height of the receiving space for throw blasting = 18m×15m×32m.

[0099] After production verification, various economic and technical indicators are excellent. The recovery rate of the mine room is about 90%, the depletion rate is ≤1.2%, the mining ratio is about 2.25m / kt, the large block output rate is ≤5%, and the density of the blast pile in the throwing blasting zone is greater than 90%; the semi-bottom ore receiving structure has high ore extraction efficiency, and the ore transportation distance of the whole plate area is reduced by an average of 23m; compared with the full bottom ore receiving structure, the blasting vibration, air shock wave, blasting smoke, dust, etc. are reduced year-on-year, and the safety and environmental protection working conditions are improved; the mining cost of the plate area is reduced by about 17.5%.

[0100] In addition, as shown in Table 1, the construction data under different conditions using this method are shown.

[0101] Table 1

[0102]

[0103] In summary, the blasting method of the semi-bottom receiving structure of a gently inclined-inclined ore body of the present embodiment is designed for a gently inclined-inclined ore body with an inclination angle of 15-50°, and a directional throwing on one side and a loosening blasting technology on the other side are designed, and a series of data models of design parameters such as the mine room height, throwing distance, throwing angle, and bomb unit consumption are established, which form sufficient data quantification support for the mining project, solve the problems of large amount of mining waste rock and scattered ore logistics when the prior art is used for the receiving structure of the gently inclined-inclined ore body, and greatly increase the mine room height and expand the mining intensity of the stope. At the same time, it can effectively improve the economic and technical indicators of the stope, and achieve the optimization goals of a mine room height of 15-75m, a mine room production capacity of 460-1450t / d, a mine room recovery rate of 84.9-96%, a depletion rate of 0.1-1.73%, and a mining ratio of 1.69-8.31m / kt.

[0104] The examples described in the present invention are merely descriptions of the preferred implementation modes of the present invention, and are not intended to limit the concept and scope of the present invention. Without departing from the design concept of the present invention, various modifications and improvements made to the technical solutions of the present invention by engineers and technicians in this field should all fall within the protection scope of the present invention.

Claims

1. A method for blasting a semi-bottom ore structure of a gently inclined-inclined ore body, comprising the following steps:

1. Collect relevant data on the ore body and determine the geological conditions, inclination and layout of the ore body; 2. Build a geometric model of the mine room based on the data collected in step 1; 3. According to the data collected in step 1, determine the throwing distance, explosive consumption and throwing angle of throwing blasting; Fourth, based on the calculation results of steps two and three, a semi-bottom receiving structure is constructed, and cast blasting is carried out on one side of the gently inclined-inclined ore body and loosening blasting is carried out on the other side.

2. The blasting method of a semi-bottom ore receiving structure of a gently inclined-inclined ore body according to claim 1, characterized in that: Establishing the geometric model of the mine chamber includes determining the mine chamber height and the location of the semi-bottom receiving structure.

3. The blasting method of a semi-bottom ore receiving structure of a gently inclined-inclined ore body according to claim 2, characterized in that: The height of the mine chamber is determined according to the following formula: H≤L max .tanθ+h min ; Where H is the height of the mine room (m), θ is the inclination of the ore body (°), B is the horizontal thickness of the ore body (m), and L max is the set maximum economic throw distance (m), h min is the minimum hole depth of the set throwing blasting (h min =1.5~2.0m), P0 is the set waste rock mixing rate (%), γ 矿 is the specific gravity of ore (t / m 3 ), γ 废 is the specific gravity of waste rock (t / m 3 ), R 矿 is the unit ore revenue (yuan / t), γ 废 It is the unit waste rock profit and loss (Yuan / t).

4. The blasting method of a semi-bottom ore receiving structure of a gently inclined-inclined ore body according to claim 2, characterized in that: The semi-bottom receiving structure is based on the bottom structure of the loose blasting partition of the stope, and also serves as the receiving space of the throwing blasting partition. Its positioning is expressed by the offset distance between the center line of the cutting groove and the marginal line of the lower plate ore body, which is determined according to the following formula: When the bottom is a flat structure, When the bottom is a trench structure, Among them, x is the offset distance (m), b is the cutting groove width (m), 8B1 is the mine room width (m), β1 is the side hole angle of the upward fan-shaped blasthole (°), and k2 is the centering coefficient of the trench in the mine room width direction (k2=1~1.7, 1 when centered).

5. The blasting method of the semi-bottom receiving structure of a gently inclined-inclined ore body according to claim 1 is characterized in that: The throwing distance of the throwing blast is determined according to the following formula: L i ≤(H-H i )·tanθ; Among them, L i is the throwing distance of each row of blastholes (m), H i is the vertical depth of the blasthole (m).

6. The blasting method of the semi-bottom receiving structure of a gently inclined-inclined ore body according to claim 5, characterized in that: The unit consumption of explosives for throwing blasting is determined according to the following formula: 0.9≤q1≤1.6kg / m 3 ; Where g is the acceleration due to gravity (9.8 m / s 2 ), β is the throwing angle of the blasting (°), Q is the unit effective energy of the explosive type used (kJ / kg), M is the unit ore mass (M = 1000γ·1m 3 , kg), q1 is the unit consumption of explosives for loosening blasting of ore and rock (1.0~2.0kg / m 3 ), q2 is the unit consumption of explosives for rock displacement (kg / m 3 ), q n Unit consumption of explosives for rock throwing blasting (kg / m 3 ).

7. The blasting method of the semi-bottom receiving structure of a gently inclined-inclined ore body according to claim 6, characterized in that: When performing upward throwing blasting, the throwing angle of the throwing blasting is determined according to the following formula: Where, h is the design throw height (m); When performing downward throw blasting, the throw angle of the blast hole in the last blasting sequence of throw blasting is determined according to the following formula: β = -θ.

8. The blasting method of the semi-bottom ore receiving structure of a gently inclined-inclined ore body according to claim 7, characterized in that: The pitch angle is not greater than 23.45°.

9. The blasting method of a semi-bottom ore receiving structure of a gently inclined-inclined ore body according to claim 1, characterized in that: During mining, the mine room near the upper wall of the ore body is arranged perpendicular to the direction of the ore body, the width of the cutting groove is consistent with the width of the mine room, and the direction of the minimum resistance line of the blasthole points to the goaf area of ​​the cutting groove.

10. The blasting method of the semi-bottom receiving structure of a gently inclined-inclined ore body according to claim 1, characterized in that: The pre-splitting blasting technology is used, and the side holes of the blasthole array are arranged in an arc shape.

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