RU2224110C1 - Process of arrangement of high walls in outline of stripping - Google Patents

Abstract

FIELD: mining industry, open cast development of deposit. SUBSTANCE: process of arrangement of high walls includes drilling of line and breaking holes, charging and blasting of breaking holes, shipment of rocks. First dummy holes of line row are drilled to height of wall at distance of 100-400 diameters of holes away from blocks of mass blasts and with distance of 2-3 diameters of hole between holes. Then buffer inclined holes are drilled at distance of 10-14 diameters of holes over surface and at distance of 4-5 diameters of holes away from line row of holes in lower part. Distance between buffer holes in row is 4-6 diameters of holes. Then breaking holes are drilled in first working subshelf. Buffer inclined holes with distributed charges including three charges, upper, center and lower, securing crushing of rock intervals between inclined and line rows of holes and section of rock interval between line row of dummy holes brought together with density of charges 3.0-3.5, 2.5-2.8, 1.0-2.0 kg/r m in upper, center and lower part of inclined holes correspondingly are first charged and then blasted. Thereupon breaking holes are charged and blasted with short delay by rows, rock is shipped from upper working subshelf. At final stage operations of drilling breaking holes, their charging, blasting and rock shipment from face of second working subshelf are carried out. EFFECT: enhanced stability of high walls thanks to decreased disturbance in mass near line. 3 dwg

Description

The invention relates to the mining industry and can be used for ejection of high ledges during the development of mineral deposits quarry.

There is a method of ejection of ledges on the limiting contour of the quarry, in which, when mining is going to the zone of ejection, a series of closely spaced wells are drilled on the limiting contour of the quarry, a distributed explosive charge is placed in them, sufficient to shoot the rock gap from the rocks between the wells, and explodes ahead of the working wells [1].

The disadvantage of this method is that when using charges in the lower and middle parts of the slope with a density of 3-4 kg / pog. m is the destruction of the mowing part of the massif, which subsequently leads to intensive scree formation of ledges in the quarries. In addition, due to the overburden of the working wells of the lower approach and their explosion on the Berm horizon, the near-surface part of the berm massif is destroyed to a depth of 4-5 m (10-20 charge diameters).

There is a method of ebullation of ledges, which consists in the simultaneous development of a contour strip with a width of 6-7 m by blasting wells of the contour row [2].

The disadvantage of this method is that when blasting the charges of the working wells in the edge band, the destruction in the edge mass extends to a distance of 100-140 charge diameters. In this case, the ejection of the ledges is carried out already violated by the explosion of the charges of the working wells of the mowing rock mass.

There is a method of ejection of ledges, including the creation on the contour of the quarry of a cutting gap, working out the mowing array to the plane of the cutting gap and the subsequent ejection of the ledge by blasting charges in shortened wells [3].

The disadvantage of this method is that this forms a convex profile of the ledge, and when you create a berm at the base of the lower dual approach, the slope angle of the double ledge is reduced. In addition, the proposed method for eclipsing the ledges cannot be carried out when setting to the extreme position in high ledges with steep angles by doubling the working ledges.

There is a method of ejection of high ledges, which consists in the fact that at a distance equal to 14 diameters of the wells from the limiting contour of the quarry, a shielding gap is created to the height of two sub-steps, followed by the development of two sub-steps [4]. After its completion, in the plane of the high ledge to be rebuilt, a number of contour wells are drilled on the limiting contour to the entire height of the ledge with a depth of 45 m. After blasting charges in contour wells with a density of 4-8 kg / linear meter. m for the upper two sub-steps and a density of 1-2 kg / line. m for the lower ledge, the safety pillar collapses, and at the last stage, the lower access is refined to the screening gap.

The disadvantage of this method is that a cutting gap is created twice, the applied amount of explosives in the upper part of the cutting gap does not guarantee against destruction and cracking in the marginal array of ledges. The surface layer of the berm is also destroyed, this will eventually lead to shedding and, in some cases, to creep off part of the slope. In addition, it is difficult to observe the parallelism of the wells over the entire 45-meter height of the high ledge due to the overburden of the working wells above the ledge.

The proposed method for overhanging the ledges cannot be carried out when setting the high ledges with steep angles to the limit position by doubling the working ledges.

The closest to the proposed technical essence and the achieved result is a method for ejection of ledges, which involves drilling holes in the gap at a close distance from each other without placing explosives in them, and a cutting gap is created when blasting holes in the near-edge zone (“smooth blasting”) [5 ] (prototype).

The disadvantage of this method is that during the explosion of explosives in the boreholes of the near-edge strip with a width of 9-12 m, not only a gap is created, but also the edge mass and, especially, the surface layer of the ledge are disturbed. In addition, the surface layer of the ledge platform (berm) has already been violated by the explosion of explosives in the working wells drilled with an excess.

The proposed method for overhanging the ledges cannot be carried out when setting the high ledges with steep angles to the limit position by doubling the working ledges.

The aim of the present invention is to increase the stability of high ledges by reducing violations of the near-edge array and cracking and to reduce scree formation and creep of the ledges.

This goal is achieved by the fact that in the known method for ejection of ledges, including drilling contour and boreholes, loading and blasting, shipping rocks, first drill the contour row with a distance of 2-3 diameters of the wells between the wells over the entire height of the high ledge and at a distance 100-140 diameters of the charge from blocks of mass explosions in the quarry, which excludes violations in the near-mass array, then they drill a buffer row of adjoining deviated wells, which serve to create a buffer “cushion” of the well in each worker odustupe or the entire height of the shoulder, and the charge exploded buffer and fender wells, produce shipping rocks. Moreover, first, buffer wells are charged and blown up to create a buffer cushion, then the boreholes are shot in a short slow manner, while buffer wells are charged with dispersed charges, the value of which in the upper part is designed for crushing the rock between the contour and buffer wells, and in the middle and lower parts the charge It is designed to cut the rock gap between the contour row wells and to form a flat and smooth surface of the plane of the rebuilt ledge without destruction by explosive charges and influence charges of the boreholes, and after their blasting, the rocks are shipped first at the top of the working sub-access, then the underlying working access.

In FIG. 1-3 shows a general diagram of two working substages and elements of the technology of work. In FIG. 1 shows the bevelled ledge 1, two working sub-steps 2, 3 with contour 4, buffer 5 wells. In FIG. 2 dispersed charge in deviated wells: in the upper part 6, the middle part 7, the lower part 8 in combination with single contour wells 4. In FIG. 3 shows the formed buffer zone 9 with the appropriate parameters and the boreholes 10 in the upper working step 2.

The created slope surface of the ledge without violations is made at a distance of 100-140 diameters of explosive charges from mass explosions in the quarry and is protected from the action of blast hole explosions that are blown up behind the buffer wells in a short-delayed manner, with a buffer pad, has no micro- and macro-destruction and will be resistant to shedding and creeping slopes of the ledge.

Buffer wells are drilled with a slope sufficient to create shear forces along the plane of contour idle wells.

The upper part of the buffer wells is charged with charges that ensure the crushing of the rock gap to contour wells during the explosion, and in the middle and lower part the charges provide crushing and the creation of shearing forces along the rock gaps along the plane between the contour wells. Considering that the resistance line along the entire height of the deviated wells for these blasting conditions varies from the maximum in the upper part to the minimum in the lower part of the wells, and the resistance line along the rock gap between the contour wells is minimal, the explosive charge of crushing in the upper part of the deviated wells is selected within 10 -14 well diameters, and the lower one according to crushing conditions 4-5 well diameters. An additional increase in charges in the middle and lower parts of deviated wells by the cut of the rock gap between the contour wells is 2-3 well diameters. With a resistance line in the upper part of deviated wells 3.2-3.5 m, in the middle part 2-2.7 m, in the lower part 1.-2 m, the magnitude of the charges can be minimized. Therefore, breaking can be carried out by charges with an annular gap and a charge density of 4-6 kg / pog. m in the upper part of deviated wells, 3-3.5 kg / linear. m in the middle part and 1.5-2 kg / linear. m at the bottom of deviated wells.

With this design of single contour wells and deviated buffer wells, the design of the charges of the buffer wells, their density and the width of the stripped layers, as well as the width of the well created in advance of 25-30 cm, not only the traces of the wells remain on the surface of the built-in ledge, but also excluded micro- and macro-destruction of the near-surface and marginal rock mass; therefore, the slope will be less prone to weathering and, therefore, to shedding and creeping.

Execution example.

The method of ejection of a high ledge on the limiting contour of the quarry is illustrated by the schemes shown in FIG. 1-3, and is as follows. On the limiting contour of the quarry, it is necessary to rebuild the continuous ledge 1 with a height of 30-45 m by doubling and setting up 15-meter ledges 2, 3. When mining is approaching on the upper working approach 2 to the limiting contour of the quarry, a number of contour wells are drilled at a distance of 25-30 m 4 with a depth of 30 m with a distance between them of 0.4-0.5 m. Then, 3.2-3.5 m from the built-up ledge 1, a series of deviated wells 5 are drilled to create a buffer in the explosion of working wells 5 in a short-delayed manner. The distance between deviated wells is 2-3 m.

Their depth corresponds to the depth of the contour wells. In the lower part of the double ledge, the gap between the contour row of wells and inclined buffer wells is 1-2 m.

Then carry out charging and blasting of inclined buffer wells. Moreover, the weight of the explosive charge in deviated wells is divided into 3 parts: a crushing charge 6 is placed in the upper part with a line of least resistance 2.7-3 m and a charge density of 3-4 g / pog. m of the well, in the middle part the line of least resistance is 2.3-2.5 m and a charge of 7 is created at a loading density of 2.6-2.8 kg / pog. m of wells, taking into account the crushing of the rock gap to the contour wells and the cut of the rock gap between the contour wells. In the lower part of the buffer wells create a charge of 8 with a line of least resistance of 1.5-2 m with a loading density of 1.5-2 kg / pog. m for crushing rock gaps between deviated wells and between the last and contour row of idle wells, as well as cutting the rock gap between contour wells.

After creating a buffer zone 9 to protect the near-surface slope layer and the contour array from destruction during the production of mass explosions in the quarry and development of the contour blocks, drilling and blasting boreholes 10 are carried out in a short-delayed manner on the first working approach at a height of 15 m initially, and after the rock is harvested, similar operations are carried out and on the second work step.

Typical drilling and blasting parameters are used to practice working sub-steps: well diameter 250 mm, drilling depth 17.5 m, distance from the buffer row of inclined wells 3.5–4 m, distance between wells in a row 6–7 m, distance between rows of wells 6 -7 m, the weight of the explosive charge in the well is 480 kg. Moreover, the first row of boreholes in front of the buffer wells is tilted to the side of the buffer wells at an angle of 80 ° to overcome the line of least resistance in the lower part of the working approach and deviated wells.

Blasting of the first row of drill wells from subsequent rows of drill wells is carried out with a slowdown of 20-25 ms to reduce the dangerous seismic effect in the explosion of charges of the drill wells.

BWR parameters for the buffer series of deviated wells:

- well diameter 190-250 mm

- drilling depth 30.5 m

- distance between wells 2.5-3 m

a) the charge in the upper part of the wells

- stemming length 3 m

- charge length 8 m

- type of charge with an annular gap

- charge density 3.0-3.5 kg / linear. m

- charge weight 26 kg

b) the charge in the middle of the wells

- charge length 8 m

- type of charge with an annular gap

- charge density 2.5-2.8 kg / linear. m

- charge weight 21.6 kg

c) the charge at the bottom of the wells

- charge length 8 m

- type of charge with an annular gap

- charge density 1.5-2.0 kg / linear. m

- charge weight 14.6 kg

Well contour parameters

- well diameter 190-250 mm

- the distance between the wells of 0.3-0.5 m

After the explosion of the buffer deviated wells and the formation of a buffer for the formed double high slope, they begin to develop the upper working ledge by drilling and blasting the boreholes. After the breed is harvested, similar operations are performed on the lower work step. After completion of the cleaning of the rock on the lower subsurface, the formed high slope has traces of wells without micro- and macro-fractures in the vicinity of the contour wells themselves, thereby increasing the stability of the slope.

Due to the increased stability of high ledges, it is possible to increase their inclination angle to vertical (90 °) in low- and medium-fractured rocks, as well as the general angle of the built-up slope of the quarry side. This will significantly reduce the volume of overburden excavation in the quarry.

Study conducted with respect to apatite Norkpahkskomu career showed that reducing the volume of stripping when implementing the method as compared with the project may be about 25 million m ³ of capping by hanging board and 10-15 million. ^M3 on the footwall deposits.

With an average cost of excavation of 1 m ³ overburden 30 rub. the total effect of the implementation of the method may be about 1200 million rubles.

Sources of information

1. Golitsyn V.V., Ivanov S.V., Zhukovsky Y.M. Issues of stability of the sides of iron ore quarries // Designing the enterprises of the mining industry. - M .: Nedra, 1976 .-- S. 48-59.

2. Galustyan E.L. Improving the design of non-working sides of quarries // Mining Journal. - 1996. - N 1, 2. - S. 93-95.

3. Auth. St. USSR N 1025886 A, E 21 C 41/00, 30.06.83, Bull. 24.

4. Auth. St. USSR N 1670133 Al, E 21 C 41/26, 08/15/91, Bull. thirty.

5. Brotakek I., Water I. Contour blasting in mining and construction. - Per. from Czech Ed. Prof. Dr. Sc. B.N. Kutuzova. - M .: Nedra, 1983, 144 p. (prototype).

Claims (1)

A method for ejecting high ledges on the limiting contour of a quarry, including drilling contour and breaker wells, loading and blasting drill holes, shipping rocks, characterized in that they first drill the contour row to the height of the ledge at a distance of 100-140 well diameters from the blocks of mass explosions and with a distance between wells of 2-3 well diameters (idle wells), then inclined buffer wells are drilled at a surface distance of 10-14 well diameters, and in the lower part, at a distance of 4-5 well diameters from the wells urea row of wells at a distance between the buffer wells in the range of 4-6 well diameters, then drill the boreholes in the first working step, then drill and blast the deviated wells with dispersed charges (three charges: upper, middle and lower), which provide rock crushing the gaps between the deviated and contour rows of wells and a section of the rock gap between the contour series of adjacent idle wells, with the charge density in the upper, middle and lower parts of the deviated wells, respectively about 3-3.5, 2.5-2.8, 1-2 kg / m pog., then they charge and blow up the boreholes in a short-delayed manner in rows, carry out the shipment of rocks on the upper working step and at the final stage perform drilling operations wells, their blasting and shipment of rocks from the bottom of the second working approach.

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