Method for constructing a safe environment for mining ore bodies in a ventilation inclined shaft

Abstract

The application discloses a kind of mining safety environment construction methods of inclined shaft under ore body, first to the present situation of mining area investigation and analysis: investigation content includes mined-out area occurrence state, the spatial relationship of main mining area and original main inclined shaft, the analysis and determination of buffer pad, the influence of mined-out area treatment on original ventilation system correlation;Then the original ventilation system is reformed, the position and length of newly added shaft and level roadway are determined, and the ventilation system scheme is repaired;Again, the setting position and quantity of chamber are set according to local conditions, a suitable number of explosive packages are arranged in the chamber, the blasting network and detonation mode are determined, and millisecond collapse blasting is used between chambers;After blasting, waste rock is filled into mined-out area as a supplementary buffer pad, and a stable and reliable new ventilation system is constructed on the basis of the original ventilation system, ensuring the safety environment of mining under inclined shaft ore body.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mining, in particular to a method for constructing a safe environment for mining ore bodies in a ventilation inclined shaft. BACKGROUND

[0002] With the continuous expansion of mining production scale, the production section also moves down, and the main ore body has been mined for many years, which forms a three-dimensional mispositioning and various-shaped goaf in the mine. The remaining ore pillars in the goaf are mainly top pillars, interval pillars and peach-shaped pillars. At present, the main mining body mainly exists below the main ventilation facility. With the mining production activities, when the ore pillars are recycled, it will cause deformation, damage or even collapse of the ventilation channels in the original ventilation system of the mine. Therefore, selecting a reasonable goaf treatment method, relying on the existing development engineering of the goaf, reducing the hazards caused by the movement of the rock mass in the goaf, and implementing a supplementary scheme of the ventilation system have practical significance for ensuring the safety of the lower mining and constructing a safety mining guarantee system. SUMMARY

[0003] The purpose of the present application is to provide a method for constructing a safe environment for mining ore bodies in a ventilation inclined shaft, relying on the existing development engineering of the goaf, supplementing the original main ventilation facility, and constructing a safety mining guarantee system.

[0004] To achieve the above-mentioned purpose, the technical solution adopted by the present application is as follows:

[0005] A method for constructing a safe environment for mining ore bodies in a ventilation inclined shaft, comprising the following steps:

[0006] Step one, investigation and analysis of the present situation of the mining area: the investigation content includes the occurrence state of the goaf, the spatial relationship between the main mining area and the original main ventilation inclined shaft, the analysis and determination of the buffer cushion layer, and the influence of the goaf treatment on the original ventilation system;

[0007] Step two, ventilation system modification: according to the occurrence state of the goaf and the analysis of the influence of the goaf treatment on the original ventilation system, the position and length of the newly added shaft are determined, the position and length of the newly added flat roadway are determined, the brushing scheme of the existing section less than 3x3m roadway is determined, and the ventilation system scheme is constructed and repaired;

[0008] Step three, setting and construction of the chamber: according to the investigation and analysis of the present situation of the mining area in step one, the setting position and quantity of the chamber are set according to the local conditions, a suitable number of bagged rock powder emulsion explosive packs are arranged in the chamber, the explosive packs are neatly coded, the middle part of the explosive pack is prevented from being detonated to enhance the transmission effect; the blasting network adopts a complex network connection, and the detonation mode is non-electric lead detonator detonation; the micro-difference collapse blasting is used between the chambers;

[0009] The waste rock after blasting is filled into the mined-out area as a supplementary buffer layer, and a stable and reliable new ventilation system is constructed on the basis of the original ventilation system, so as to ensure the safe environment of the ore body mining in the ventilation inclined shaft.

[0010] Preferably, in step two, a plurality of temporary wind barriers are arranged on the ventilation system, the wind barriers are arranged at the good roof, the surrounding rock is grooved to a depth of greater than or equal to 0.2 m, and a fence and a warning sign are arranged outside the wall.

[0011] Preferably, the wind barrier is built by wood or plastic plate, the plate is jointed into a fish scale shape, and the surface is coated with a mixture of yellow mud and lime without cracks and air leakage.

[0012] Preferably, in step two, the cross-sectional size of the newly added shaft is 2*3 m.

[0013] Preferably, in step two, the cross-sectional size of the newly added flat roadway is 3*3 m.

[0014] Preferably, in step three, the chambers are arranged to be distributed on both sides of the mined-out area, each chamber is about 18 m away from the boundary of the mined-out area, and the distance between each chamber is about 20-30 m.

[0015] Preferably, in step three, the chamber engineering adopts an "L" type arrangement, the chamber has a cross section of 2m*2m and a length of 2m, the connecting roadway has a cross section of 2m*2m, the chamber and the connecting roadway are connected by a connecting cross roadway, the cross section of the connecting cross roadway is 1.2m*2m, the length is about 5m, the distance between the detour and the chamber is about 10m, and the cross section of the detour is 2m*2m.

[0016] By the method, the new ventilation system is constructed on the basis of maintaining the original ventilation system, a proper number of chambers are arranged, the waste rock in the mined-out area is collapsed as a supplementary buffer layer through scientific and reasonable chamber blasting, the safe environment of the ore body mining in the ventilation inclined shaft is constructed, the safety of mining is ensured, and the mining rate is improved. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a schematic diagram of the overall line of the ventilation reconstruction in the embodiment;

[0018] Figure 2 is a plan view of the newly added shaft and roadway engineering in the ventilation reconstruction in the embodiment;

[0019] Figure 3 is a plan layout of the chamber blasting engineering in the embodiment

[0020] Figure 4 is a schematic diagram before the chamber collapse;

[0021] Figure 5 is a schematic diagram after the chamber collapse. DETAILED DESCRIPTION

[0022] The application will be further described in detail below with reference to the accompanying drawings.

[0023] As Figure 1 shown in a kind of ventilation inclined shaft ore body mining safety environment construction method, with the mine reconstruction of a certain lead-zinc mine in northwest as example, including the following steps:

[0024] Step one, mine area present situation investigation analysis: before mine reconstruction, production mainly concentrates in 800m and 750m middle section, part of the mine room has been mined out, 850m above ore body has been mined out with shallow hole, the remaining ore pillar is mainly top pillar, interval column and peach-shaped ore pillar, is recovered with different ways in combination with mined-out area treatment;When the ore pillar recovery of this ore body reaches 800m middle section, the highest height of mined-out area is 168m, the remaining mined-out area penetrates to southeast direction, the strike length is 200m, the widest part of the mined-out area is 60m, the highest part of the recovery height reaches 980m elevation, and the volume of the mined-out area is about 740,000m 3 .

[0025] In the process of recovering 850m middle section ore pillar, waste rock will inevitably fall off and mix, causing dilution, and some lost ore will be left in the mined-out area. According to the experience of previous ore pillar recovery, the comprehensive loss rate of ore pillar recovery is 20%, the dilution rate is 35%, and the recoverable ore quantity of 850m middle section ore pillar is about 250,000 tons, so about 53,476m 3 of waste rock bulk is consumed, and 20,930m 3 of ore bulk is replenished;After the complete recovery of 850m middle section ore pillar, the remaining buffer cushion bulk in the mined-out area is 93,627m 3 , according to the revised average area of 850m middle section and 900m middle section, which is 5,531m 2 , the thickness of the buffer cushion above 850m middle section is calculated as 16.9m.

[0026] In the process of recovering the ore pillar above 800m middle section, loss and dilution will still occur. If the ore pillar above 800m middle section is completely recovered, the ore quantity of the ore pillar is about 220,000 tons. Considering the comprehensive loss rate and dilution rate of ore pillar recovery, about 47,051m 3 of waste rock bulk is consumed, and 18,419m 3 of ore bulk is replenished;When the 800m ore pillar is completely recovered, the remaining buffer cushion bulk in the mined-out area is 64,995m 3 , according to the revised average area of 800m middle section and 850m middle section, which is 5,558m 2 , the thickness of the buffer cushion above 800m middle section is calculated as 11.7m. Therefore, at least 8.3m thick buffer cushion, with a bulk of 46,158m, needs to be supplemented to form a 20m thick buffer cushion above 800m middle section.3 .

[0027] The No.4 inclined shaft in the ore body is located above the mined-out area of the ore body between the elevations of 975.4-981.2 m, and is also within the 800 m middle section moving zone. The shortest distance from the highest point of the mined-out area after the blasting of the 926 m level chamber to the No.4 inclined shaft is only 32.5 m without considering the natural caving after the blasting of the chamber, which is within the scope of safety hazards.

[0028] Step two, ventilation system reconstruction: from the 950 level at the drop-off point of the No.4 inclined shaft, the existing roadway engineering at the 950 level is mainly utilized, such as Figure 2 , bypassing the empty area from the east to the vicinity of the No.4 inclined shaft, and upwardly excavating a 52.6 m high ventilation raise, and then excavating a 13 m long flat roadway to connect the No.4 inclined shaft and the newly added raise; the cross section size of the newly added raise is 2x3 m, the cross section size of the newly added flat roadway is 3x3 m, the roadway with a cross section less than 3x3 m needs to be expanded by an average of 1 m, and the total length of the expanded roadway is 50 m. A new return air passage is established as shown in Figure 1 , and the ventilation resistance of the route is 0.132 NS 2 / m 8 .

[0029] In order to ensure the success of the designed ventilation route, temporary wind barriers are set up at multiple places along the route. The wind barriers are set up at a good position in the roof, and the surrounding rock is excavated to a depth of ≥0.2 m, and a fence and warning signs are set up outside the wall. The wind barriers are built with wood or plastic boards, the boards are jointed into a fish scale shape, and the surface is coated with a mixture of yellow mud and lime without cracks and air leakage.

[0030] Step three, setting and construction of the chamber:

[0031] (1) Determination of chamber parameters

[0032] Minimum resistance line W (m): the minimum resistance line of the explosive package is the core problem of the explosive distribution, and is taken as 15-18 m according to the rock properties of the ore body;

[0033] The calculation formula of the explosive package spacing a is:

[0034]

[0035] Wherein: n is the blasting action index, generally taken as 0.75-1, and W refers to the minimum resistance line;

[0036] The calculation formula of the upper rupture radius R is:

[0037]

[0038] The calculation formula of the lower rupture radius R' is:

[0039]

[0040] wherein: β is the destruction coefficient, which is related to the ground slope angle φ,

[0041]

[0042] (2) Chamber engineering layout

[0043] According to the amount of rock bulk required to be supplemented after the calculation of the minimum thickness of the buffer cushion layer, 6 chambers are arranged on the north and south sides of the mined-out area of the 900m middle section ore body, wherein 3 chambers are arranged on the south side, which are No. 15, 13 and 11 chambers, and 3 chambers are arranged on the north side, which are No. 09, 07 and 03 chambers, each chamber is about 18m away from the boundary of the mined-out area, and the distance between each chamber is about 20-30m.

[0044] The chamber engineering adopts "L" type layout, the chamber cross section is 2m x 2m, the length is 2m, the cross section of the connecting lane is 2m x 2m, the chamber and the connecting lane are connected by a connecting cross lane, the cross section of which is 1.2m x 2m, the length is about 5m, the distance from the detour to the chamber is about 10m, and the cross section is 2m x 2m.

[0045] The designed rock bulk volume of the 6 chambers is 50398m 3 , the engineering layout diagram is shown in Figure 3 、 Figure 4

[0046] (3) Chamber blasting scheme

[0047] A suitable number of bagged rock powder emulsion explosive packs are arranged in the chamber, the explosive packs are neatly coded, the middle of the explosive pack is prevented from being detonated to enhance the transmission effect; the blasting network adopts a complex network connection, and the detonation mode is non-electric lead detonator detonation; differential collapse blasting is used between chambers;

[0048] The waste rock after blasting is filled into the mined-out area as a supplementary buffer cushion layer, and a stable and reliable new ventilation system is constructed on the basis of the original ventilation system, which ensures the safe environment of the mine body mining in the ventilation inclined shaft.

Claims

1. A method for constructing a safe environment for mining ore bodies in a ventilation inclined shaft, characterized in that: The method comprises the following steps: Step one, investigation and analysis of the present situation of the mining area: the investigation content includes the occurrence state of the goaf, the spatial relationship between the main mining area and the original main ventilation inclined shaft, the analysis and determination of the buffer cushion, and the influence of the goaf treatment on the original ventilation system; Step two, ventilation system reconstruction: according to the occurrence state of the goaf and the analysis of the influence of the goaf treatment on the original ventilation system, the position and length of the new shaft are determined, the position and length of the new flat roadway are determined, the brushing scheme of the roadway with a section less than 3*3m is determined, the ventilation system scheme is constructed and repaired, a plurality of temporary wind barriers are arranged on the ventilation system, the wind barriers are arranged at the top of the wall, the surrounding rock is dug to a depth of greater than or equal to 0.2m around the wall, a fence and a warning sign are arranged outside the wall, the section size of the new shaft is 2*3m, and the section size of the new flat roadway is 3*3m; Step three, setting and construction of the chamber: according to the investigation and analysis of the present situation of the mining area in step one, the setting position and quantity of the chamber are set according to local conditions, a proper number of bagged rock powder emulsion explosive bags are arranged in the chamber, the explosive bags are arranged in order, an initiator is arranged in the middle of the explosive bag to enhance the transmission effect, a complex network connection is used in the blasting network, a non-electric lead blasting cap is used for initiation, micro-difference collapse blasting is used between chambers, the arranged chambers are distributed on both sides of the goaf, the distance between each chamber and the goaf boundary is 18m, and the distance between each chamber is 20-30m; After blasting, the waste rock is filled into the goaf as a supplementary buffer cushion, a stable and reliable new ventilation system is constructed on the basis of the original ventilation system, and the safety environment of the mining body in the ventilation inclined shaft is ensured.

2. The method for constructing a safe environment for mining a down-dip ore body of a ventilation inclined shaft according to claim 1, characterized in that: The wind barrier is built with wood or plastic plate, the plate is overlapped into a fish scale shape, and the surface is coated with a mixture of yellow mud and lime without cracks and air leakage.

3. The method for constructing a safe environment for mining a deposit in a ventilation inclined shaft according to claim 1 or 2, characterized in that: In step three, the chamber project is arranged in an "L" shape, the chamber section is 2m*2m, the length is 2m, the connecting roadway section is 2m*2m, the chamber and the connecting roadway are connected by a connecting cross roadway, the section is 1.2m*2m, the length is 5m, the detour distance from the chamber is 10m, and the section is 2m*2m.

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