A method of dumping inclined base in a backfold area of an open pit mine

Abstract

The present application relates to a kind of open pit anticline area inclined base dump method, comprising the following steps: dividing the end zone of stope into accelerated propulsion area, when accelerated propulsion area is forwardly propelled distance D, rough surface blasting is carried out to the exposed inclined base;End slope and inclined base meet at the intersection to start with the strike angle θ End slope pseudo-inclined dump, until with inclined base is connected, forms dump step;Stope propulsion distance is D', completes a single step dump disposal;The above steps 1~3 are recycled, after forming a single step dump step, continue to advance along the direction of inclination of inclined base and pseudo-inclined dump direction.This application does not occupy other land, forms dump in anticline area, which is convenient for discharge of stripping material, saves disposal cost, through end slope pseudo-inclined dump method, uses the support of end slope and inclined base to dump, which can improve the stability of inclined base dump, prevent coal seam slope surface from sliding.

Description

Technical Field

[0001] This invention belongs to the field of open-pit coal mine spoil disposal technology, and specifically relates to a method for spoil disposal at an inclined base in an open-pit mine anticline area. Background Technology

[0002] The overburden disposal process in open-pit coal mines is a crucial technological step in the production process. Overburden from open-pit mines is typically dumped directly into the goaf area of ​​the open-pit mine via transport channels, forming an internal overburden dump. The slope of the internal overburden dump is generally 50 meters away from the mining face. Being close to the mining and stripping face and with a relatively high slope, the stability of the internal overburden dump directly affects the production safety of the open-pit mine. Besides the main factors affecting stability, including the properties of the soil and rock of the overburden material, the properties of the soil and rock of the overburden base, and the slope morphology, the base morphology of the internal overburden dump is also a significant factor influencing its stability. Generally, a horizontal or near-horizontal base results in high stability. Conversely, a sloping base transforms the internal overburden dump slope into a sloping slope, reducing stability and posing significant safety hazards.

[0003] Currently, when open-pit mines in China encounter inclined foundations during production, they generally choose to avoid dumping materials in the inclined foundation area. Instead, they raise the dumping elevation of the dumping site in the horizontal foundation area or dump the stripped material in an external dumping site. This results in increased dumping distance and greater dumping elevation difference. At the same time, the goaf in the anticline area cannot be effectively covered with soil, forming a goaf. Land resources cannot be effectively utilized, while mining costs are increased and corporate profits are reduced. Summary of the Invention

[0004] The purpose of this invention is to provide a method for removing soil from the inclined foundation of an anticline area in an open-pit mine.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A method for removing soil from the inclined foundation of an open-pit mine anticline includes the following steps:

[0007] Step 1: Divide the endwall area of ​​the stope into an accelerated advance zone. When the accelerated advance zone advances a distance D, perform rough blasting on the exposed inclined base.

[0008] Step 2: After the exposed inclined base surface has been blasted, start the pseudo-inclined soil removal at the intersection of the end wall and the inclined base at the strike angle θ until it connects with the inclined base, forming a soil removal step and gradually moving forward to remove soil.

[0009] Step 3: The mining area continues to advance forward, with a mining area advancement distance of D′, completing one single-bench soil and waste disposal.

[0010] Step 4: Repeat steps 1 to 3 above. After forming a single-step dumping platform, continue to advance along the inclined direction of the inclined base and the pseudo-inclined dumping direction. A new dumping platform will begin to form at the bottom of a single step, gradually forming a pseudo-inclined dumping site in the anticline area.

[0011] Preferably, the propulsion distance D is:

[0012]

[0013] Where C is the width of the dumping area between adjacent dumping steps; R is the turning radius of the dump truck; L1 is the length of the dump truck; and F is the distance from the center of the rear axle of the dump truck to the edge of the step.

[0014] Preferably, the radius of the blasting funnel for the rough blasting is the same as the depth of the funnel, and the depth of the rough blasting is 1-3m.

[0015] Preferably, in step S3, when a single-step dumping is formed, the mining area advance distance is... for:

[0016] l

[0017] Where B is the width of the spoil disposal platform; B′ is the horizontal distance of the spoil disposal platform slope; and l is the safe distance between the spoil disposal site and the lowest bench of the mining area.

[0018] Preferably, the width B of the waste disposal tray is:

[0019]

[0020] Where H is the height of the dumping platform; γ is the coal seam dip angle; and α is the natural angle of repose of the dumped material.

[0021] Preferably, the horizontal distance B′ of the drainage flat slope is:

[0022] .

[0023] Preferably, the orientation angle θ is the angle between the orientation and the geographic North Pole in a clockwise direction, and the orientation angle is determined using the stereographic projection method.

[0024] The beneficial effects of this invention are:

[0025] 1. This invention enhances the friction of the inclined dumping base by roughening the coal seam floor with blasting, thereby increasing the coal seam's anti-sliding ability and preventing landslides along the base slope.

[0026] 2. The end-side pseudo-inclined soil dumping method of the present invention utilizes the end sides and inclined bottom plate to support the soil dumping site, which can effectively improve the stability of the inclined base soil dumping site. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the pseudo-inclined soil removal platform relationship in the anticline region according to an embodiment of the present invention;

[0028] Figure 2 This is a schematic diagram of the surface blasting in an embodiment of the present invention;

[0029] Figure 3 This is a schematic diagram of the soil removal profile after the rough blasting is carried out in an embodiment of the present invention. Detailed Implementation

[0030] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0031] This embodiment uses actual parameters from the Anjialing open-pit mine to illustrate the invention.

[0032] like Figure 1-3 As shown, the present invention provides a method for removing soil from an inclined foundation in an open-pit mine anticline area, comprising the following steps:

[0033] Step 1: Divide the end face area of ​​the mining area into an accelerated advance zone. When the accelerated advance zone advances a distance D, perform rough blasting on the exposed inclined basement to form a fracture zone in the weak layer of the basement and increase the friction of the basement.

[0034] Specifically, based on the occurrence of the coal seam floor and production status in open-pit mines, the endwall area of ​​the mining area is divided into an accelerated advancement zone, and other areas are divided into a coordinated advancement zone. The accelerated advancement zone of the endwall accelerates the exposure of the lowest coal seam's inclined floor, with the aim of quickly traversing the anticline zone and achieving a turning point in the mining area.

[0035] Specifically, the propulsion distance D is: Where C is the width of the dumping platform between adjacent dumping steps, which is related to the rolling distance of large rocks; R is the turning radius of the dump truck; L1 is the length of the dump truck; and F is the distance from the center of the rear axle of the dump truck to the edge of the step.

[0036] Based on the truck parameters and the properties of the dumped rock at Anjialing open-pit mine, the dump width C=2m, the truck turning radius R=15.2m, the truck length L1=15.6m, the distance from the center of the truck's rear axle to the edge of the bench F=1m, and the advancing distance D is taken as 65m.

[0037] Among them, the rough blasting parameters adopt 8m×8m blast hole parameters with a blasting action index of 1, that is, the radius of the blasting funnel is the same as the depth of the funnel, and the rough blasting depth is 1-3 meters according to the geological conditions on site.

[0038] Step 2: After the exposed inclined base surface has been blasted, start the pseudo-inclined soil removal at the intersection of the end wall and the inclined base at the strike angle θ until it connects with the inclined base, forming a soil removal step and gradually moving forward to remove soil.

[0039] Specifically, for pseudo-inclined dumping, the strike angle θ is the angle between the strike and the geographic North Pole in a clockwise direction. The strike angle θ is determined by stereographic projection. Since the attitude of the anticline and the end slope is fixed, the strike and slope angle of the dumping site can be preliminarily determined based on the positional relationship between the intersection of the end slope and the anticline in the stereographic projection and the slope circle of the dumping site. Only when the combined intersection projection of the two and the dumping site slope projection are on one side and the dip angle is greater than the slope dip angle will it be in a stable structure.

[0040] The Anjialing open-pit mine has a dip base of 80° and a dip angle of 12°, and a side slope of 105° and a dip angle of 28°. The dip of the spoil heap is determined to be 105° and a dip angle of 14° by stereographic projection polar method, and the angle θ of the inclined spoil heap is 15°.

[0041] Step 3: The accelerated advance area of ​​the stope continues to advance, with a stope advance distance of D′, completing one single-bench soil and waste disposal.

[0042] Specifically, in the process of single-step soil dumping and disposal on an anticlinal slope, the advance of the mining area and the disposal of the spoil heap are carried out simultaneously. When the height of the spoil heap reaches the designed disposal height H=30m, a single-step spoil heap is formed. At this time, the advance distance of the mining area is D′, and a single-step soil dumping and disposal is completed.

[0043] More specifically, the advance distance D′ of the mining area is

[0044] ,

[0045] Where B is the width of the spoil disposal platform; B′ is the horizontal distance of the spoil disposal platform slope; and l is the safe distance between the spoil disposal site and the lowest bench of the mining area.

[0046] The width B′ of the waste disposal plate is:

[0047]

[0048] The horizontal distance B′ of the drainage flat slope is:

[0049]

[0050] Where H is the height of the dumping platform; γ is the coal seam dip angle; and α is the natural angle of repose of the dumped material.

[0051] The advance distance D′ of the mining area is related to the parameters of the earthwork bench, such as... Figure 1As shown, the advance distance of a single-bench stope forming a spoil heap is related to the coal seam dip angle, the safe distance between the spoil heap and the stope, and the natural angle of repose of the rock. Based on the coal seam occurrence state and the physical and mechanical properties of the rock materials in Anjialing Mine, the average coal seam dip angle is determined to be 12º, the natural angle of repose of the rock is 35º, the safe distance between the spoil heap and the lowest bench of the stope is 50m, and the stope advance distance when a single bench is formed is... ;

[0052] Step 4: Repeat steps 1 to 3 above, and continue to advance along the dip direction of the coal seam floor and the pseudo-inclined spoil disposal direction, and start to form a new spoil disposal step at the bottom of a single step; gradually form a pseudo-inclined spoil disposal area in the anticline zone.

Claims

1. A method for removing soil from the inclined foundation of an anticline area in an open-pit mine, characterized in that, Includes the following steps: Step 1: Divide the endwall area of ​​the stope into an accelerated advance zone. When the accelerated advance zone advances a distance D, perform rough blasting on the exposed inclined base. Step 2: After the exposed inclined base surface has been blasted, start the pseudo-inclined soil removal at the intersection of the end wall and the inclined base at the strike angle θ until it connects with the inclined base, forming a soil removal step and gradually moving forward to remove soil. Step 3: The accelerated advance zone of the mining area continues to advance, with the mining area advancing a distance of [distance to be filled in]. Complete a single-stage soil and waste disposal; Step 4: Repeat steps 1 to 3 above. After a single-step dumping platform is formed, continue to advance along the inclined direction of the inclined base and the pseudo-inclined dumping direction. A new dumping platform will begin to form at the bottom of a single step, gradually forming a pseudo-inclined dumping site in the anticline area. Wherein, the orientation angle θ is the angle between the orientation and the geographic North Pole in a clockwise direction, and the orientation angle is determined by the stereographic projection method; The propulsion distance D is: Where C is the width of the dump truck left between adjacent dumping steps; R is the turning radius of the dump truck; L1 is the length of the dump truck; and F is the distance from the center of the rear axle of the dump truck to the edge of the step. In step 3, the mining area advance distance for: l Where B is the width of the spoil disposal platform; B′ is the horizontal distance of the spoil disposal platform slope; and l is the safe distance between the spoil disposal site and the lowest bench of the mining area. The width B of the waste disposal plate is: Where H is the height of the dumping platform; γ is the coal seam dip angle; and α is the angle of repose of the dumped material. The horizontal distance of the abandoned flat slope for: 。 2. The method for removing soil from the inclined foundation of an open-pit mine anticline area according to claim 1, characterized in that, The radius and depth of the blasting funnel in the surface blasting are the same, and the depth of the surface blasting is 1-3m.

Images