Segmented medium-length hole mining method for top pretreatment under broken ore rock condition

Abstract

The invention provides a subsection medium-length hole mining method for top pretreatment under the condition of broken ore rock, and belongs to the field of mining. According to the method, before each stope of a to-be-mined subsection is mined, a drilling roadway of each stope in an adjacent upper subsection is constructed in advance, and the drilling roadway is pre-supported; a horizontal blast hole perpendicular to the lateral wall of the rock drilling roadway is constructed in the bottom of the rock drilling roadway, the horizontal blast hole is blasted in a spaced charging mode in the trend of the rock drilling roadway, and a bottom plate of the adjacent upper section stope is separated from a top plate of the stope to be mined. According to the method, pretreatment and pre-supporting of the top of the stope are combined, the effect of stabilizing the rock drilling roadway and the bottom jambs in the upper subsection stope is achieved, and the phenomenon that the rock drilling roadway and the bottom jambs are affected by blasting disturbance and an empty stope during stoping in the lower stope under the condition of broken ore rocks, and the structure is damaged and collapses is avoided; according to the scheme, production connection between the stopes of the upper section and the lower section is more compact, the mining progress and safety of the stopes are improved, the process is simple, and the practical application value is high.

Description

Technical Field

[0001] The present invention relates to the technical field of mining, and particularly to a sublevel medium-deep hole mining method for top pre-treatment under the condition of broken ore and rock. Background Art

[0002] At present, for steeply inclined medium-thick and above ore bodies under the condition of broken ore and rock, the sublevel medium-deep hole subsequent filling mining method is mostly used for mining, and the overall mining sequence of the mine is from bottom to top; when production is carried out in the lower sublevel stope, the rock drilling roadway at the bottom of the adjacent stope directly above this stope has been constructed and has been treated with shotcrete, bolt and wire mesh support. In the sublevel medium-deep hole subsequent filling mining method, the rock drilling roadway of the upper sublevel stope is constructed in advance. On the one hand, it provides a passage for the layout of the filling pipeline in the lower sublevel stope, and on the other hand, it speeds up the construction progress of the development engineering and ensures the stability of the mine production capacity. However, in actual engineering, affected by the condition of broken ore and rock and the blasting disturbance of the lower sublevel stope, it is difficult to keep the constructed rock drilling roadway of the upper sublevel intact after the completion of the lower sublevel stope. Even under the support conditions of bolt and wire mesh or shotcreting, the positions of the rock drilling roadway and the triangular ore pillars on both sides are mostly damaged, and a certain degree of collapse occurs. The collapsed rock drilling roadway will affect the mining progress and safety of the upper sublevel stope. If it is repaired again, the mining cost will be increased, the economic benefit of ore body extraction will be reduced, and the safety risk will be increased.

[0003] A patent discloses a large structure filling mining method for extremely broken ore bodies with roof reconstruction and side wall strengthening. The stope is divided into sectional stopes. There are two sublevels, upper and lower, in the sectional stope, and mining is carried out in steps. First, the lower drift filling mining method is used to mine the top of the sublevel, and an artificial false roof is constructed. In the second-step stope, grouting anchor cables are used to support the two side walls of the first-step stope to form a relatively stable mining environment in the first-step stope. The first-step stope is mined by the upward sublevel filling method. After the first-step stope is mined and filled, the second-step stope is mined by the sublevel rock drilling stage open stoping subsequent filling method; under the action of the artificial false roof, grouting anchor cables for strengthening the side walls and high-strength filling bodies, the mining environment of the second-step stope is improved, and efficient upward fan-shaped medium-deep hole mining of all ore bodies in the second-step stope is realized. However, in this mining method, grouting anchor cables are constructed through the side walls of the second-step stope, and relatively thick filling body artificial false roofs (6 - 8 m) are constructed on the roofs of each stope, and complex mining processes are used to reduce the roof exposure time, making the entire mining project relatively complex, the mining efficiency relatively low, increasing the ore extraction cost, and having relatively low practical application value in the mining project of extremely broken ore bodies. Summary of the Invention

[0004] In view of the technical problems existing in the background art, the present application provides a sectional medium-deep hole mining method for top pre-treatment under broken ore-rock conditions, aiming to solve the technical problems that the constructed roadways or ore pillars in the upper stope are easily affected by the construction of the lower stope during the mining of steeply inclined medium-thick or above ore bodies under broken ore-rock conditions, resulting in damage or collapse.

[0005] The present application provides a sectional medium-deep hole mining method for top pre-treatment under broken ore-rock conditions, comprising the following steps: S1. The ore body to be mined is segmented in height, and the mining sequence of each segment is from bottom to top; stopes are arranged along the strike of the ore body for each segment, and each stope adopts a stoping method of mining every other one. S2. Before the mining of each stope in any segment to be mined, the drilling roadways of each stope in the current segment and each stope in the adjacent upper segment are constructed in advance; pre-support is carried out on the drilling roadways of the stope in the adjacent upper segment of the stope to be mined, horizontal blast holes perpendicular to the side wall of the drilling roadway are constructed at the bottom thereof, and the horizontal blast holes are blasted by adopting an interval charging method along the strike of the drilling roadway to separate the floor of the stope in the adjacent upper segment from the roof of the stope to be mined. S3. The stope to be mined is blasted and mined by upward fan-shaped medium-deep holes, and filling is carried out immediately after the mining is completed. The mining of all the stopes in the segment to be mined is completed by adopting the method of mining every other one. S4. Repeat the methods of steps S2 to S3 to continue the mining of each stope in the adjacent upper segment from bottom to top until the mining of the entire ore body to be mined is completed.

[0006] In the technical solution of the present application, before the mining of each stope in any segment to be mined, the drilling roadways of each stope in the adjacent upper segment are constructed in advance, pre-support is carried out on the drilling roadways, horizontal blast holes perpendicular to the side wall of the drilling roadway are constructed at the bottom thereof, and the horizontal blast holes are blasted by adopting an interval charging method along the strike of the drilling roadway to separate the floor of the stope in the adjacent upper segment from the roof of the stope to be mined. In this way, the function of stabilizing the drilling roadways and the bottom ore pillars in the upper stope is achieved, and the phenomenon of structural damage and collapse caused by the influence of stope blasting disturbance and open stope during the mining of the lower segment stope under broken ore-rock conditions is avoided; this solution makes the production connection between the upper and lower segment stopes more compact, improves the mining progress and safety of the stope, and has a simple mining process and high practical application value.

[0007] As a further improvement of the present invention, in step S2, for the horizontal blast holes constructed at the bottom of the drilling roadway of the stope in the adjacent upper segment, the height from the floor of the drilling roadway is not more than 0.1 m, and the construction length exceeds the boundary of the stope where the drilling roadway is located by 0.3 to 0.5 m.

[0008] Blasting is carried out by means of interval charging for horizontal blast holes. The setting of non-charged empty holes can play the role of air interval during blasting, which is beneficial to controlling the blasting effect, reducing the damage to the integrity of the bottom ore pillar, and avoiding the loss of the bottom support function of the ore pillar; limiting the distance between the horizontal blast holes and the bottom plate of the drilling roadway and the distance exceeding the stope boundary is also to control the blasting range and effect, so that the bottom plate of the adjacent upper-stage stope and the roof of the stope to be mined are completely separated, and the stability of the stope is not damaged.

[0009] As a further improvement of the present invention, in step S3, when blasting and mining the stope to be mined by using upward fan-shaped medium-deep holes, horizontal shallow holes are simultaneously used to blast and mine the triangular ore pillars on both sides of the drilling roadway at the bottom of the stope to be mined.

[0010] By using horizontal blast holes to pre-crack the upper and lower boundaries of adjacent sectional stopes, the recovery difficulty of the triangular ore pillars at the bottom of the stope is reduced, the recovery integrity of the ore pillars is improved, and they can be blasted and recovered together with the normal mining rows; in this way, the loss of ore is reduced as a whole, and the recovery rate of broken ore and rock is increased.

[0011] As a further improvement of the present invention, in step S1, the ore body to be mined is a steeply inclined medium-thick or above ore body under the condition of broken ore and rock, the dip angle of the steeply inclined medium-thick or above ore body is greater than 50°, and the ore body thickness is above 5 m. This technical solution solves the technical problem that when mining a steeply inclined medium-thick or above ore body under the condition of broken ore and rock by the sublevel medium-deep hole subsequent filling mining method, the existing roadways or ore pillars in the upper-stage stope are easily affected by the construction of the lower-stage stope and are damaged or collapsed.

[0012] As a further improvement of the present invention, the aperture of the horizontal blast hole is 60 - 80 mm, the length is 5 - 6 m, and the row spacing of the horizontal blast holes along the walking direction of the drilling roadway where they are located is 1.0 - 1.2 m.

[0013] The setting of the above horizontal blast hole parameters is to ensure the blasting effect of the horizontal blast holes and separate the bottom plate of the adjacent upper-stage stope from the roof of the stope to be mined, without damaging the surrounding environment and affecting the normal mining of the ore body.

[0014] As a further improvement of the present invention, in step S2, before mining each stope in the lowest sublevel of the ore body to be mined, the drilling roadway in the stope is pre-supported, and horizontal blast holes perpendicular to the side wall of the drilling roadway are constructed at the bottom. Blasting is carried out by means of interval charging for the horizontal blast holes along the walking direction of the drilling roadway to separate the bottom plate of the stope in this sublevel from the bottom surrounding rock.

[0015] For each stope in the lowest sublevel of the orebody to be mined, horizontal blast holes are also used for presplitting blasting to separate the stope floor from the bottom surrounding rock in this sublevel, which is beneficial to the stability of stope stoping and the recovery of bottom pillars, and avoids the increase in ore dilution rate caused by the mixing of bottom surrounding rock.

[0016] As a further improvement of the present invention, the pre-support includes first constructing bolt holes and cable bolt holes on the side wall and roof of the drilling roadway, installing bolts and cable bolts, applying prestress to the cable bolts and grouting, then laying and fixing a wire mesh on the inner surface of the drilling roadway, and finally spraying concrete on the inner surface of the drilling roadway.

[0017] The combination of cable bolts and shotcrete with wire mesh support improves the support effect. Cement is grouted through the cable bolt holes, and the cement penetrates into the surrounding rock through the fissures, so as to achieve the purpose of consolidating the rock formation and enhancing the stability of the rock formation. The cable bolts are prestressed by special equipment, so that the rock formations penetrated by the cable bolts can be tightly fitted together, thus playing the role of strengthening the rock formation and preventing the roadway from collapsing and deforming. Finally, shotcrete is sprayed to make the whole roadway more integral. The tension of the cable bolts can act on the roadway surface as a whole through the wire mesh and the shotcrete layer to protect the roadway from being damaged.

[0018] This technical solution combines the two processes of stope top pretreatment and pre-support to protect the already constructed drilling roadway and pillars in the upper sublevel from the influence of broken ore-rock conditions and blasting disturbance in the lower sublevel stope, and solves the technical problem of safe and efficient mining of sublevel medium-deep hole stopes under broken ore-rock conditions.

[0019] As a further improvement of the present invention, in step S2, before the mining of each stope in any sublevel to be mined, several ore-drawing access roads need to be set between adjacent stopes with the drilling roadway as the working face. The ore-drawing access roads connect the drilling roadways of adjacent stopes and form an angle of 40° - 50° with the drilling roadway. In step S1, before the stoping of the orebody to be mined, the development and cutting engineering of the orebody is carried out, including sublevel haulage headings arranged between each sublevel and along the orebody strike, orepass connecting headings and orepasses perpendicular to the sublevel haulage headings.

[0020] As a further improvement of the present invention, the rows of the bolt holes and cable bolt holes are alternately arranged along the trend of the drilling roadway. The bolt holes are arranged on the inner surface of the drilling roadway with a mesh size of 1m * 1m, the hole diameter is 40 - 50 mm, and the length of the bolts is 1.8 - 2.2 m; the row spacing of the cable bolt holes is 2.0 - 2.2 m, the hole diameter is 50 - 70 mm, and the length is 6 - 8 m; the mesh size of the wire mesh is 100mm * 100mm, and the diameter of the steel bar raw material is 5 - 8 mm; the thickness of the shotcrete is 25 - 30 mm.

[0021] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application, it can be implemented according to the content of the specification. And in order to make the above and other purposes, features and advantages of this application more obvious and understandable, the specific embodiments of this application are specifically given below. Brief Description of the Drawings

[0022] In order to more clearly illustrate the technical solution of this application, the drawings used in this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0023] Figure 1 It is a schematic diagram of the stope structure in the Ⅰ-Ⅰ direction in the sublevel medium-deep hole mining method for top pre-treatment under broken ore and rock conditions in the embodiment of this application; Figure 2 It is Figure 1 a schematic diagram of the stope structure in the Ⅱ-Ⅱ direction; Figure 3 It is Figure 1 a schematic diagram of the stope structure in the Ⅲ-Ⅲ direction; Figure 4 It is the collapse situation of the drilling roadway and the ore pillars on both sides in the existing sublevel medium-deep hole subsequent filling mining method; Figure 5 It is a schematic diagram of the layout of horizontal blast holes in the sublevel medium-deep hole mining method for top pre-treatment under broken ore and rock conditions in the embodiment of this application; Figure 6 It is a schematic diagram of the pre-support structure in the sublevel medium-deep hole mining method for top pre-treatment under broken ore and rock conditions in the embodiment of this application.

[0024] Description of the reference numerals in the drawings: 100, sublevel; 110, drilling roadway; 120, horizontal blast hole; 130, upward fan-shaped medium-deep hole; 140, horizontal shallow hole; 151, bolt; 152, cable bolt; 160, ore-drawing drift; 170, sublevel haulage roadway; 180, ore-pass connecting roadway; 190, ore pass; 200, ore; 300, filling body. Detailed Embodiments

[0025] The embodiments of the technical solution of this application will be described in detail below with reference to the drawings. The following embodiments are only used to more clearly illustrate the technical solution of this application, so they are only examples and cannot be used to limit the protection scope of this application.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this application belongs; the terms used herein are for the purpose of describing specific embodiments only and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above drawings are intended to cover non-exclusive inclusion.

[0027] In the description of the embodiments of this application, technical terms such as "first" and "second" are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity, specific order or primary-secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "a plurality of" is more than two, unless otherwise specifically defined.

[0028] Referring to "embodiments" herein means that specific features, structures or characteristics described in connection with the embodiments can be included in at least one embodiment of this application. The phrase appearing in various positions in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0029] In the description of the embodiments of this application, the orientation or positional relationship indicated by technical terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the embodiments of this application and simplifying the description, rather than indicating or implying that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of this application.

[0030] For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of this application can be understood according to specific circumstances.

[0031] At present, for steeply inclined medium-thick or above ore bodies under broken ore and rock conditions, the sublevel medium-deep hole post-fill mining method is mostly used for mining, and the overall mining sequence of the mine is from bottom to top; when production is carried out in the lower sublevel stope, the rock drilling roadway at the bottom of the adjacent stope directly above this stope has been constructed and shotcrete-bolt-mesh support treatment has been carried out. In the sublevel medium-deep hole post-fill mining method, the rock drilling roadway of the upper sublevel stope is constructed in advance. On the one hand, it provides a passage for the layout of the filling pipeline in the lower sublevel stope. On the other hand, it is to speed up the construction progress of the development engineering and ensure the stability of the mine production capacity. However, in actual engineering, affected by the broken ore and rock conditions and the blasting disturbance of the lower sublevel stope, the constructed rock drilling roadway in the upper sublevel is difficult to be well preserved after the completion of the lower sublevel stope. Even under the support conditions of bolt-mesh or shotcreting, the positions of the rock drilling roadway and the triangular ore pillars on both sides are mostly damaged, and a certain degree of collapse occurs (as shown in the attached Figure 4 of the specification), and the collapsed rock drilling roadway will affect the mining progress and safety of the upper sublevel stope. If it is repaired again, the mining cost will be increased, the economic benefit of ore body extraction will be reduced, and the safety risk will be increased.

[0032] In order to solve the technical problem that the constructed roadway or ore pillar in the upper sublevel stope is easily affected by the construction of the lower sublevel stope and is damaged or collapsed during the mining of steeply inclined medium-thick or above ore bodies under the current broken ore and rock conditions, this application provides a sublevel medium-deep hole mining method with top pre-treatment under broken ore and rock conditions. Before the mining of each stope in any sublevel to be mined, the rock drilling roadways of each stope in the adjacent upper sublevel are constructed in advance, and pre-support is carried out on the rock drilling roadways. Horizontal blast holes perpendicular to the sidewall of the rock drilling roadway are constructed on both sides of the stope from the bottom of the rock drilling roadway, and the horizontal blast holes are blasted by adopting the method of interval charging along the trend of the rock drilling roadway, so as to separate the floor of the adjacent upper sublevel stope from the roof of the stope to be mined. In this way, the function of stabilizing the rock drilling roadway and the bottom ore pillar in the upper sublevel stope is achieved, and it is avoided that under the broken ore and rock conditions and during the mining of the lower sublevel stope, it is affected by the blasting disturbance and open stope of the stope and the phenomenon of structural damage and collapse occurs; this scheme makes the production connection between the upper and lower sublevel stopes more compact, improves the mining progress and safety of the stope, and the mining process is simple, with high practical application value.

[0033] For the convenience of description, the following embodiments take a sublevel medium-deep hole mining method with top pre-treatment under broken ore and rock conditions in an embodiment of this application as an example for description.

[0034] Please refer to Figures 1 to 3 , the embodiment of this application provides a sublevel medium-deep hole mining method with top pre-treatment under broken ore and rock conditions, including the following steps: S1. The ore body to be mined is subleveled by 100 in height, and the mining sequence of each sublevel 100 is from bottom to top; the stopes are arranged along the trend of the ore body, and each stope adopts the stoping method of mining every other one; S2. Before mining each stope in any segmented area 100 to be mined, advance the construction of the drilling headings 110 for each stope in the current segmented area 100 and each stope in the adjacent upper segmented area; pre-support the drilling headings 110 of the stope in the adjacent upper segmented area of the stope to be mined. Construct horizontal blast holes 120 perpendicular to the sidewall of the drilling heading 110 from the bottom of the drilling heading 110 to both sides of the stope. Carry out blasting on the horizontal blast holes 120 in a way of interval charging along the trend of the drilling heading 110 to separate the floor of the stope in the adjacent upper segmented area from the roof of the stope to be mined. S3. Use upward fan-shaped medium-deep holes 130 to carry out blasting and stoping on the stope to be mined. Immediately after the stoping is completed, use the filling body 300 for filling. Adopt the method of mining one and leaving one to complete the stoping of all the stopes in the segmented area to be mined. S4. Repeat the methods in steps S2 - S3 to continue stoping the stopes in the adjacent upper segmented area from bottom to top until the stoping of the entire ore body to be mined is completed.

[0035] This mining method, before mining each stope in any segmented area 100 to be mined, advances the construction of the drilling headings 110 for each stope in the adjacent upper segmented area and pre-supports the drilling headings 110. Construct horizontal blast holes 120 perpendicular to the sidewall of the drilling heading 110 from the bottom of the drilling heading 110 to both sides of the stope. Carry out blasting on the horizontal blast holes 120 in a way of interval charging along the trend of the drilling heading 110 to separate the floor of the stope in the adjacent upper segmented area from the roof of the stope to be mined. In this way, it achieves the effect of stabilizing the drilling headings 110 and the bottom pillars in the upper segmented stope, and avoids the phenomenon of structural damage and collapse due to the influence of stope blasting disturbance and open stope during the stoping of the lower segmented stope under the condition of broken ore and rock. This solution makes the production connection between the stopes in the upper and lower segments more compact, improves the stoping progress and safety of the stope, and has a simple mining process and high practical application value.

[0036] Please refer to Figure 5 As shown, in some embodiments, in step S2, for the horizontal blast holes 120 constructed at the bottom of the drilling heading 110 of the stope in the adjacent upper segmented area, the height from the bottom of the horizontal blast holes 120 to the floor of the drilling heading 110 does not exceed 0.1 m, and the construction length extends 0.3 - 0.5 m beyond the boundary of the stope where the drilling heading 110 is located. It should be noted that the height distance between the horizontal blast holes 120 and the floor of the drilling heading 110 is the distance from the bottom surface of the horizontal blast holes 120 to the floor surface of the drilling heading 110.

[0037] In the technical solution of the embodiment of the present application, blasting is carried out by means of interval charging for the horizontal blast holes 120. The setting of the non-charged empty holes can play an air interval role during blasting, which is beneficial to controlling the blasting effect, reducing the damage to the integrity of the bottom ore pillar, and preventing the ore pillar from losing its bottom support effect; limiting the distance between the horizontal blast holes 120 and the bottom plate of the drilling roadway 110 and the distance exceeding the stope boundary is also to control the blasting range and effect, so that the bottom plate of the adjacent upper-stage stope and the roof of the stope to be mined are completely separated, and the stability of the stope is not damaged.

[0038] Further, in some embodiments, in step S3, when blasting and mining the stope to be mined with upward fan-shaped medium-deep holes 130, horizontal shallow holes 140 are simultaneously used to blast and mine the triangular ore pillars on both sides of the bottom drilling roadway 110 of the stope to be mined.

[0039] In the technical solution of the embodiment of the present application, by using the horizontal blast holes 120 to pre-crack the upper and lower boundaries of the adjacent stage 100 stopes, the recovery difficulty of the triangular ore pillars at the bottom of the stope is reduced, the recovery integrity of the ore pillars is improved, and they can be blasted and recovered together with the normal mining rows; in this way, the loss of ore is reduced as a whole, and the recovery rate of broken ore and rock is increased.

[0040] Further, in some embodiments, in step S1, the ore body to be mined is a steeply inclined medium-thick or above ore body under the condition of broken ore and rock. The dip angle of the steeply inclined medium-thick or above ore body is greater than 50°, and the thickness of the ore body is 5 m or more. This technical solution solves the technical problem that when the steeply inclined medium-thick or above ore body under the condition of broken ore and rock is mined by the subsequent filling mining method of sublevel medium-deep holes, the constructed roadways or ore pillars in the upper-stage stope are easily affected by the construction of the lower-stage stope and are damaged or collapsed.

[0041] Further, in some embodiments, the aperture of the horizontal blast holes 120 is 60-80 mm, the length is 5-6 m, and the row spacing of the horizontal blast holes 120 along the direction of the drilling roadway 110 is 1.0-1.2 m.

[0042] In the technical solution of the embodiment of the present application, the setting of the above horizontal blast hole 120 parameters is to ensure the blasting effect of the horizontal blast holes 120 and the separation effect of the bottom plate of the adjacent upper-stage stope and the roof of the stope to be mined, without damaging the surrounding environment and affecting the normal mining of the ore body.

[0043] Further, in some embodiments, in step S2, before the mining of each stope in the lowest slice 100 of the ore body to be mined, pre-support is carried out on the drilling roadway 110 in the stope, and horizontal blast holes 120 perpendicular to the side wall of the drilling roadway 110 are constructed at the bottom thereof. The horizontal blast holes 120 are blasted in a spaced-charge manner along the trend of the drilling roadway 110 to separate the floor of the stope in this slice from the surrounding rock at the bottom.

[0044] In the technical solution of the embodiment of the present application, horizontal blast holes 120 are also used for presplitting blasting in each stope in the lowest slice 100 of the ore body to be mined, to separate the floor of the stope in this slice from the surrounding rock at the bottom, which is beneficial to the stability of stope stoping and the recovery of the bottom ore pillar, and avoids the increase of the dilution rate of the ore caused by the mixing of the surrounding rock at the bottom.

[0045] Please refer to Figure 6 As shown, in some embodiments, the pre-support includes first constructing bolt holes and cable bolt holes on the side wall and roof of the drilling roadway 110, installing bolts 151 and cable bolts 152, applying prestress and grouting to the cable bolts 152, then laying and fixing a wire mesh on the inner surface of the drilling roadway 110, and finally spraying concrete on the inner surface of the drilling roadway 110.

[0046] Further, in some embodiments, the rows of the bolt holes and the cable bolt holes are alternately arranged along the trend of the drilling roadway 110. The bolt holes are arranged on the inner surface of the drilling roadway 110 with a mesh size of 1m * 1m, the hole diameter is 40 - 50 mm, and the length of the bolts 151 is 1.8 - 2.2 m; the row spacing of the cable bolt holes is 2.0 - 2.2 m, the hole diameter is 50 - 70 mm, and the length is 6 - 8 m; the mesh size of the wire mesh is 100mm * 100mm, and the diameter of the steel bar raw material is 5 - 8 mm; the thickness of the sprayed concrete is 25 - 30 mm.

[0047] In the technical solution of the embodiment of the present application, the combination of cable bolts 152, bolts 151 and shotcrete mesh support is adopted to improve the support effect. Cement is grouted through the cable bolt holes, and the cement penetrates into the surrounding rock through the fissures, so as to achieve the purpose of consolidating the rock layer and enhancing the stability of the rock layer. The cable bolts 152 are prestressed by special equipment, so that the rock layers penetrated by the cable bolts 152 can be tightly fitted together, thus playing a role in strengthening the rock layer and preventing the roadway from collapsing and deforming. Finally, shotcrete is sprayed to make the whole roadway more integral. The tension of the cable bolts 152 can act on the surface of the roadway as a whole through the wire mesh and the shotcrete layer to protect the roadway from being damaged.

[0048] This technical solution combines the two processes of pre-treatment and pre-support of the stope top, protecting the previously constructed drilling roadway 110 and ore pillars in the upper section from the influence of broken ore and rock conditions and the blasting disturbance of the stope in the lower section, and solving the technical problem of safe and efficient mining of sublevel medium-deep hole stopes under the existing broken ore and rock conditions.

[0049] Further, in some embodiments, in step S2, before the mining of each stope in any sublevel to be mined, a number of ore-drawing access roads 160 need to be set between adjacent stopes with the drilling roadway 110 as the working face. The ore-drawing access roads 160 are used to draw the caved ore 200, and the ore-drawing access roads 160 communicate with the drilling roadways 110 of adjacent stopes, and the included angle with the drilling roadway 110 is 40° - 50°. In step S1, before the mining of the ore body to be mined starts, the development and cutting engineering of the ore body is carried out, including the sublevel haulage drift 170 arranged between each sublevel 100 along the ore body strike, the ore pass connecting drift 180 and the ore pass 190 perpendicular to the sublevel haulage drift 170.

[0050] Specific embodiments are listed below. It should be noted that the embodiments described below are exemplary and are only used to explain the present application and should not be construed as a limitation of the present application. For those without specific techniques or conditions noted in the embodiments, they shall be carried out according to the techniques or conditions described in the literature in the field or according to the product specifications.

[0051] Example 1 This embodiment provides an actual application of a sublevel medium-deep hole mining method with top pre-treatment under broken ore and rock conditions for steeply inclined medium-thick and above ore bodies under certain broken ore and rock conditions, including the following steps: S1. The ore body to be mined is divided into sublevels 100 in height, the height of the sublevels 100 is 27 m, and the mining sequence of each sublevel 100 is from bottom to top; the stopes are arranged along the ore body strike for each sublevel 100, the width of the stope is 15 m, and each stope adopts the stoping method of mining every other one. S2. Before the mining of each stope in any sublevel 100 to be mined, the drilling roadways 110 of each stope in the current sublevel 100 and each stope in the adjacent upper sublevel are constructed in advance; the drilling roadway 110 of the adjacent upper sublevel stope to the stope to be mined is pre-supported, horizontal blast holes 120 perpendicular to the side wall of the drilling roadway 110 are constructed at the bottom on both sides of the stope, and the horizontal blast holes 120 are blasted in a spaced charging manner along the trend of the drilling roadway 110 to separate the floor of the adjacent upper sublevel stope from the roof of the stope to be mined. Among them, the height of the horizontal blast hole 120 is 0.05 m from the floor of the drift 110 for drilling, and the construction length exceeds the boundary of the stope where the drift 110 is located by 0.5 m; the aperture of the horizontal blast hole 120 is 60 mm, the length is 6 m, and the row spacing of the horizontal blast holes 120 along the direction of the drift 110 for drilling is 1.0 m; the pre-support includes first constructing bolt holes and cable bolt holes on the side wall and roof of the drift 110 for drilling, installing bolts 151 and cable bolts 152, grouting in the cable bolt holes and applying prestress to the cable bolts 152, then laying and fixing a wire mesh on the inner surface of the drift 110 for drilling, and finally spraying concrete on the inner surface of the drift 110 for drilling; Structural parameters of the pre-support: Bolt holes are constructed according to a grid of 1m * 1m, the aperture of the bolt holes is 42mm, the bolts 151 are made of deformed steel bars with a diameter of 18mm and a length of 2m, the aperture of the cable bolt holes is 60mm, the cable bolts 152 are made of steel strands with a diameter of 21.8mm, the length of the cable bolt holes is 7m (the end of the upward cable bolt 152 is in the stable rock formation, and the end of the nearly horizontal cable bolt 152 is in the stable ore and rock in the adjacent stope), 6 cable bolts 152 are arranged in one cable bolt row face, and the row face spacing of the cable bolts 152 is 2m; the diameter of the steel bar raw material of the wire mesh is 6mm, and the grid is of the specification of 100mm * 100mm; the spacing of the bolts 151 is 1 m, the row spacing of the cable bolts 152 is 2 m, and during on-site construction, the row faces of the cable bolts 152 and the bolts 151 are staggered along the direction of the drift 110 for drilling, so that the cable bolt holes and the bolt holes will not cross each other; S3. For the stope to be mined, upward fan-shaped medium-deep holes 130 are used for blasting and stoping, and at the same time, horizontal short holes 140 are used for blasting and stoping the triangular ore pillars on both sides of the drift 110 for drilling at the bottom of the stope to be mined. Immediately after stoping, backfilling is carried out, and the stoping of all the stopes in the mined section is completed in the way of mining every other stope; S4. Repeat the methods in steps S2 - S3 to continue stoping the stopes in the adjacent upper section from bottom to top until the stoping of the entire ore body to be mined is completed.

[0052] This embodiment combines the two processes of pre-treatment and pre-support at the top of the stope, protecting the drift for drilling and ore pillars that have been constructed in the upper-section stope from the influence of broken ore and rock conditions and blasting disturbance in the lower-section stope, making the production connection between the upper and lower-section stopes more compact, improving the mining progress and safety of the stope, reducing the loss of ore as a whole, increasing the recovery rate of broken ore and rock, and having a simple mining process and high practical application value.

[0053] It should be noted that this application is not limited to the above embodiments. The above embodiments are only examples, and embodiments with the same structure in essence as the technical idea and achieving the same effects within the scope of the technical solution of this application are all included in the technical scope of this application. In addition, within the scope of not departing from the gist of this application, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways constructed by combining some of the constituent elements in the embodiments are also included in the scope of this application.

Claims

1. A segmented medium-deep hole mining method with top pretreatment under broken ore and rock conditions, characterized in that: The following steps are involved: S1. Divide the ore body to be mined into sections in height, and the mining order of each section is from bottom to top; arrange the stopes of each section along the direction of the ore body, and adopt the method of mining every other stope in each stope; S2. Before mining of each stope in any segment to be mined, construct in advance the rock drilling tunnels of each stope in the current segment and each stope in the adjacent upper segment; pre-support the rock drilling tunnel of the upper stope adjacent to the stope to be mined, construct horizontal blast holes perpendicular to the side of the rock drilling tunnel at the bottom, blast the horizontal blast holes along the direction of the rock drilling tunnel by charging at intervals, and separate the bottom plate of the adjacent upper stope from the top plate of the stope to be mined; S3, blasting and mining the stope to be mined by using upward fan-shaped medium-long holes, and backfilling immediately after mining is completed, and mining of all the stopes in the section to be mined is completed by mining one by one in alternate sections; S4. Repeat steps S2 to S3 to continue mining the adjacent upper segmented mining areas from bottom to top until the mining of the entire ore body to be mined is completed.

2. The method for segmented medium-deep hole mining under top pretreatment under broken ore and rock conditions according to claim 1, characterized in that: In step S2, the height of the horizontal blasthole constructed at the bottom of the rock drilling tunnel of the adjacent upper sub-level stope is no more than 0.1 m from the bottom plate of the rock drilling tunnel, and the construction length exceeds the boundary of the stope where the rock drilling tunnel is located by 0.3-0.5 m.

3. The method for segmented medium-deep hole mining under top pretreatment under broken ore and rock conditions according to claim 1, characterized in that: In step S3, while the upward fan-shaped medium-deep holes are used for blasting and mining the mining area to be mined, horizontal shallow holes are used for blasting and mining the triangular pillars on both sides of the rock drilling tunnel at the bottom of the mining area to be mined.

4. The method for segmented medium-deep hole mining under top pretreatment under broken ore and rock conditions according to claim 1, characterized in that: In step S1, the ore body to be mined is a steeply inclined medium-thick or thicker ore body under broken ore rock conditions, the ore body inclination angle of the steeply inclined medium-thick or thicker ore body is greater than 50°, and the ore body thickness is more than 5 m.

5. The method for segmented medium-deep hole mining under top pretreatment under broken ore and rock conditions according to claim 2, characterized in that: The aperture of the horizontal blasthole is 60-80 mm, the length is 5-6 m, and the row spacing of the horizontal blasthole along the direction of the rock drilling tunnel in which the horizontal blasthole is located is 1.0-1.2 m.

6. The method for segmented medium-deep hole mining under top pretreatment under broken ore and rock conditions according to claim 3, characterized in that: In step S2, before mining each stope in the lowest segment of the ore body to be mined, pre-support is performed on the rock drilling tunnel in the stope, and horizontal blast holes perpendicular to the side walls of the rock drilling tunnel are constructed at the bottom thereof. The horizontal blast holes are blasted along the direction of the rock drilling tunnel by means of intermittent charging, so as to separate the bottom plate of the stope in the segment from the bottom surrounding rock.

7. The method for segmented medium-deep hole mining under top pretreatment under broken ore and rock conditions according to claim 6, characterized in that: The pre-support includes first constructing anchor holes and anchor cable holes on the side walls and top plate of the rock drilling tunnel, installing anchor rods and anchor cables, applying prestress and grouting to the anchor cables, then laying and fixing metal mesh on the inner surface of the rock drilling tunnel, and finally spraying concrete on the inner surface of the rock drilling tunnel.

8. The method for segmented medium-deep hole mining under top pretreatment under broken ore and rock conditions according to claim 1, characterized in that: In step S2, before mining in each mining area of ​​any to-be-mined segment, it is necessary to use the rock drilling tunnel as the working surface and set up several mining access routes between adjacent mining areas. The mining access routes are connected to the rock drilling tunnels of adjacent mining areas, and the angle between the mining access routes and the rock drilling tunnels is 40°~50°.

9. The method for segmented medium-deep hole mining under top pretreatment under broken ore and rock conditions according to claim 1, characterized in that: In step S1, before the mining of the ore body to be mined begins, the ore body is cut and cut, including segmented transport tunnels located between the segments and along the direction of the ore body, and ore chute connecting tunnels and ore chute shafts perpendicular to the segmented transport tunnels.

10. The method for segmented medium-deep hole mining under top pretreatment under broken ore and rock conditions according to claim 7, characterized in that: The rows of the anchor holes and the anchor cable holes are alternately arranged along the direction of the rock drilling tunnel. The anchor holes are arranged on the inner surface of the rock drilling tunnel with a mesh size of 1m*1m, the hole diameter is 40~50 mm, and the length of the anchor is 1.8~2.2 m; the row spacing of the anchor cable holes is 2.0~2.2 m, the hole diameter is 50~70 mm, and the length is 6~8 m; the mesh size of the metal mesh is 100mm*100mm, and the diameter of its steel bar raw material is 5~8 mm; the thickness of the shotcrete is 25~30 mm.

Images