A pillarless sublevel caving mining method for recovering the footwall of gently inclined ore bodies

Abstract

The present invention discloses a pillarless sublevel caving mining method for recovering the footwall of gently inclined ore bodies, comprising the following steps: determining the position of the footwall recovery roadway of the ore body according to the dip angle of the footwall of the gently inclined ore body, the peach-shaped ore pillars in the upper sublevel and the residual height of the ridge; arranging vertical-strike drifts in the ore body, and connecting the vertical-strike drifts with the haulage roadway; arranging medium-deep holes in the vertical-strike drifts, and taking the part of the vertical-strike drift close to the footwall of the ore body as the cutting drift of the footwall recovery roadway; using the cavity formed after caving the vertical-strike drift as the blasting space for cutting the cutting drift; using the cavity formed after blasting the cutting drift with medium-deep holes as the blasting space for the footwall recovery roadway; arranging the footwall ore-rock boundary along the vertical strike as the alignment of the last row of medium-deep holes. The present invention utilizes the pillarless sublevel caving mining method to arrange a recovery roadway for the footwall of the ore body when mining gently inclined medium-thick or above ore bodies in the footwall, so that the overall ore recovery rate of the ore block is increased by 6.24%.

Description

Technical Field

[0001] The present invention relates to the technical field of non-pillar sublevel caving mining methods for the footwall of gently inclined medium-thick or above ore bodies, and specifically to a non-pillar sublevel caving mining method for recovering the footwall of gently inclined ore bodies. Background Technique

[0002] The non-pillar sublevel caving method is a high-efficiency mining method that uses drifts to divide the ore body and serves as drilling headings, then carries out medium-deep hole drilling, and has high mechanization, low labor consumption, high safety factor, and relatively low cost during stoping and ore drawing in the drifts.

[0003] In the non-pillar sublevel caving mining method, medium-deep holes are arranged and drilled in the drifts according to the dip angle of the upper and lower walls of the ore body, the sublevel height, and the economic rationality of the mined ore and rock. The cutting raise is used as the blasting space for the stoping of the drifts. When the ore body is thick and the dip angle of the footwall is gentle, when using a vertical strike layout, the following main disadvantages exist:

[0004] 1. Both the ore loss in the footwall ore body and the waste rock dilution are relatively large;

[0005] 2. The peach-shaped ore pillars and ridge remnants in the footwall of the upper sublevel form permanent losses;

[0006] 3. The mining cost will increase significantly. When the traditional non-pillar sublevel caving method uses a vertical strike layout, only the position of the last row of medium-deep hole alignment is adjusted according to the ore and rock boundary of the footwall to solve the above problems, but the recovery problems of the peach-shaped ore pillars and ridge remnants in the footwall of the upper sublevel ore body are not considered, resulting in a large amount of ore loss in the footwall ore body. Summary of the Invention

[0007] The purpose of the present invention is to provide a non-pillar sublevel caving mining method for recovering the footwall of gently inclined ore bodies to solve the problems raised in the above background technique.

[0008] To achieve the above purpose, the present invention provides the following technical solution: A non-pillar sublevel caving mining method for recovering the footwall of gently inclined ore bodies, including the following steps:

[0009] S1. Determine the position of the footwall recovery roadway of the ore body according to the dip angle of the footwall of the gently inclined ore body, the height of the peach-shaped ore pillars and ridge remnants in the upper sublevel. The ore body is provided with a number of vertical strike drifts, and the vertical strike drifts are connected to the transportation roadway, and the distance between two adjacent vertical strike drifts is 18 m;

[0010] S2. Medium-deep holes are arranged in the vertical strike drifts, and the part of the vertical strike drift close to the footwall of the ore body is used as the cutting roadway of the footwall recovery roadway;

[0011] S3. The cavity formed after caving the vertical strike drift is used as the blasting space for the cutting roadway slashing;

[0012] S4. The cut roadway utilizes the open stope formed after medium-deep hole blasting as the blasting space for the hanging wall recovery roadway.

[0013] S5. The hanging wall ore-rock boundary is arranged along the vertical strike as the position for the last row of medium-deep hole alignment. The height of the roof caving area formed by the hanging wall recovery roadway and the last row of medium-deep hole alignment does not exceed 7 m.

[0014] Furthermore, the hanging wall recovery roadway can be arranged in the area where the dip angle of the hanging wall of the ore body is gentle.

[0015] Furthermore, the distance between the medium-deep hole blasting range of the hanging wall recovery roadway and the last row of medium-deep hole alignment is 0.5 m.

[0016] Furthermore, the height of the cut roadway slotting exceeds the height of the upper sublevel peach-shaped ore pillar by more than 2 m.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0018] (1) The present invention utilizes the open stope formed after ore caving in the vertical strike drift as the blasting space for the cut roadway to carry out slotting. The height of the cut roadway slotting should exceed the upper sublevel peach-shaped ore pillar by more than 2 m to ensure sufficient space and fully recover the hanging wall ore body. The height of the roof caving area formed by the hanging wall recovery roadway and the last row of medium-deep hole alignment does not exceed 7 m. The roof caving area can be recovered as the peach-shaped ore pillar of this sublevel in the lower sublevel. The distance between the medium-deep hole blasting range of the hanging wall recovery roadway 3 and the last row of medium-deep hole alignment is 0.5 m to prevent damage to the medium-deep holes of the hanging wall recovery roadway or blockage of holes during the blasting of the last row of medium-deep hole alignment. Therefore, the problem of non-residual recovery of the peach-shaped ore pillar and ridge at the hanging wall of the upper sublevel ore body can be well solved, and a large amount of loss to the hanging wall ore body can be avoided.

[0019] (2) In the present invention, in the sublevel caving mining method without sill pillars, when mining the hanging wall gently inclined medium-thick or above ore body, a recovery roadway is arranged at the hanging wall of the ore body, so that the overall ore recovery rate of the ore block is increased by 6.24%, while the overall dilution rate of the ore block remains unchanged. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a top view of the structure of the present invention;

[0021] Figure 2 It is a sectional view of the structure of the present invention.

[0022] In the figure: 1, haulage roadway; 2, vertical strike drift; 3, hanging wall recovery roadway; 4, blasting space for the hanging wall recovery roadway; 5, cut roadway; 6, peach-shaped ore pillar; 7, last row of medium-deep hole alignment; 8, roof caving area. DETAILED DESCRIPTION OF THE INVENTION

[0023] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0024] Please refer to Figure 1-2 , an embodiment provided by the present invention: a non-pillar sublevel caving mining method for the recovery of the footwall of gently inclined ore bodies, comprising the following steps:

[0025] S1. Determine the position of the footwall recovery roadway 3 of the ore body according to the dip angle of the footwall of the gently inclined ore body, the peach-shaped ore pillar 6 in the upper sublevel and the residual height of the ridge. A number of vertical strike drifts 2 are arranged in the ore body, and the vertical strike drifts 2 are connected to the transportation roadway 1. The spacing between two adjacent vertical strike drifts 2 is 18 m;

[0026] S2. Medium-deep holes are arranged in the vertical strike drift 2, and the part of the vertical strike drift 2 close to the footwall of the ore body is used as the cut drift 5 of the footwall recovery roadway 3;

[0027] S3. The open stope formed after caving the vertical strike drift 2 is used as the blasting space for the cut of the cut drift;

[0028] S4. The open stope formed after blasting the cut drift 5 with medium-deep holes is used as the blasting space 6 of the footwall recovery roadway;

[0029] S5. The footwall ore-rock boundary is arranged along the vertical strike as the position of the last row of medium-deep hole alignment 7, and the height of the roof caving area 8 formed by the footwall recovery roadway 3 and the last row of medium-deep hole alignment 7 does not exceed 7 m.

[0030] In this embodiment, the footwall recovery roadway 3 can be arranged in the gently inclined area of the footwall of the ore body to ensure full recovery of the footwall ore body.

[0031] In this embodiment, the spacing between the medium-deep hole blasting range of the footwall recovery roadway 3 and the last row of medium-deep hole alignment 7 is 0.5 m.

[0032] In this embodiment, the height of the cut of the cut drift exceeds the height of the peach-shaped ore pillar 6 in the upper sublevel by more than 2 m.

[0033] Working principle: The vertical access 2 retreats to the last row of medium-depth hole rows 7 for ore body recovery towards the footwall by using the blasting space provided by the cut drift in the draw cut. The last row of medium-depth hole rows 7 is arranged at the ore-rock interface to prevent premature caving of the footwall waste rock. The vertical access 2 near the footwall serves as the cut drift 5 for the footwall recovery drift 3. After ore caving in the vertical access 2, the formed void is used as the blasting space for the cut drift 5 in the draw cut. The draw cut height of the cut drift should exceed the upper-layer peach-shaped ore pillar by more than 2 m to ensure sufficient space for fully recovering the footwall ore body. The height of the roof caving area 8 formed by the footwall recovery drift 3 and the last row of medium-depth hole rows 7 does not exceed 7 m, and the roof caving area 8 can be recovered as the peach-shaped ore pillar 6 of this layer in the lower layer. The distance between the medium-depth hole blasting range of the footwall recovery drift 3 and the last row of medium-depth hole rows 7 is 0.5 m to prevent damage to the medium-depth holes of the footwall recovery drift 3 or blockage during the blasting of the last row of medium-depth hole rows 7. The footwall recovery drift 3 retreats to mine the footwall ore body by using the blasting space provided by the cut drift 5 formed by the vertical access 2.

[0034] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or perform equivalent substitution on some of the technical features. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An undercutless sublevel caving mining method for recovering the footwall of gently inclined ore bodies, characterized in that: It includes the following steps: S1. Determine the position of the footwall recovery roadway of the ore body according to the dip angle of the footwall of the gently inclined ore body, the peach-shaped ore pillar in the upper sublevel and the residual height of the ridge. A number of vertical strike drifts are arranged in the ore body, and the vertical strike drifts are connected to the transportation roadway. The spacing between two adjacent vertical strike drifts is 18 m; S2. Medium-deep holes are arranged in the vertical strike drift, and the part of the vertical strike drift close to the footwall of the ore body is used as the cut drift of the footwall recovery roadway; S3. The open stope formed after caving the vertical strike drift is used as the blasting space for the cut of the cut drift; S4. The open stope formed after blasting the cut drift with medium-deep holes is used as the blasting space for the footwall recovery roadway; S5. The footwall ore-rock boundary is arranged along the vertical strike as the position of the last row of medium-deep hole alignment. The height of the roof-cut area formed by the footwall recovery roadway and the last row of medium-deep hole alignment does not exceed 7 m; The footwall recovery roadway is arranged in the gently inclined area of the footwall of the ore body; The spacing between the medium-deep hole blasting range of the footwall recovery roadway and the last row of medium-deep hole alignment is 0.5 m.

2. The undercutless sublevel caving mining method for recovering the footwall of gently inclined ore bodies according to claim 1, characterized in that: The height of the cut of the cut drift exceeds the height of the peach-shaped ore pillar in the upper sublevel by more than 2 m.

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