# Method for rock-blasting at open-pit mining

FIELD: mining art, in particular, open-pit mining of mineral resources by high benches.

SUBSTANCE: large-diameter single holes are replaced by a pair of divergent holes of a smaller diameter, in which one hole is always vertical, and the other one is inclined towards the bench; the single holes of the larger diameter are replaced with a pair of divergent bundles of parallel converged holes, in which one bundle is vertical, and the other is inclined towards the bench; the single holes of the larger diameter are replaced with a pair of divergent holes of a smaller diameter, in which one hole is vertical, and the other is inclined towards the bench and positioned in the vertical plane parallel with the first one and distant from it by 1-2 hole diameters; the single holes of the larger diameter are replaced by a pair of divergent bundles of parallel converging holes, in which one bundle is vertical, and the other is inclined towards the bench and positioned in the vertical plane parallel with the first one and distant from it by 1-2 hole diameters.

EFFECT: enhanced efficiency of blasting of the benches.

7 cl, 6 dwg

The invention relates to mining, in particular to the open development of mineral resources with the method of blasting high working ledges.

Known used in underground mining explosive blasting fans of deep wells in the variant system sublevel caving ore thump of hands on the ground sublevel delivery drifts. In this case, higher sublevel load-haul-drifts (vectors) are the production, from which upward divergent fans of deep wells amerivault and blow up the panel with a width of 15-30 m (two or three drift) and a height of 25-30 m (see Agoshkov M.I., S. Borisov, boyar, VA Development of ore and non-metallic deposits. M.: Nedra, 1970, s-279).

The disadvantage of this method as applied to the conditions blasting high ledges in open pits is that fans of divergent wells should always be positioned in a plane parallel to an exposed surface, which is the breaking of rock mass.

The closest in technical essence and essential features to the proposed method of blasting is a method of blasting rock at surface mines borehole charges large diameter when drilling is carried out with the working surface of the ledge in the side of his soles. After drilling sensepreserving to the explosion of the wells produce their loading and subsequent blasting (see Reference “Open pit mining”, M.: Mining Bureau, 1994, p.153-154 table 6.9 “Technical characteristics of modern drilling rigs”).

The disadvantage of this method when increasing due to technological reasons, the working height of the scarp is the inevitable necessity of advance increment the value of the resistance line explosion on the sole thump of hands ledge (LSP) and, as a consequence, the diameter of borehole charges to overcome it; thus the value of the diameter of the wells quickly goes beyond the technical capabilities of the existing drilling equipment.

The objective of the invention is to intensify and increase the efficiency of drilling and blasting and mining operations by increasing the height abusively and blasted rock ledges, improve the performance of drilling and reducing the specific consumption of EXPLOSIVES, while maintaining the required degree of fragmentation.

The problem is solved by creating a method of blasting rock high ledges in open development, including drilling down-hole, loading and blasting, in which according to the invention, the blasting of rocks are divergent pairs of wells drilled with the working surface of the ledge in the vertical plane, in which one hole in each pair of wells are drilling perpendicular to the sole of the ledge, and the second in the direction of QCD is sa bench with a tilt to his shoes at such an angle β to this inclined well crossed estimated LSP in the middle

where H is the height of the ledge, m;

d is the diameter of the hole in a pair of divergent wells, m;

q is the specific consumption of EXPLOSIVES for a given species and a given quality crushing, kg/m^{3};

γ_{CC}- density loading of EXPLOSIVES in a borehole, kg/m^{3}.

Feature blasting high ledges is the increased value of the resistance line explosion on the sole, which is in direct proportion associated with scarp ratio W=H•ctgα+C, where W is the estimated value LSP, m; H - height of the ledge, M.; α - the angle of slope of the ledge, grad.; With the magnitude of the berm security, m

Traditional blasting methods to overcome the inflated values LSP include increasing the diameter wells or power applied CENTURIES. However, this causes significant capital expenditures to upgrade drilling equipment and range used CENTURIES. At the same time, the practice of blasting shows that the diameters of the enlarged borehole charges do not provide the necessary quality crushing and development soles, especially with increasing height of the ledges of more than 15 m in the medium and hard-shot grounds rocks.

In connection with the proposed method, blasting of rocks on open development that accounts for the x cylindrical monotherapy, located in the downstream wells of large diameter, replace one or more pairs of divergent wells of smaller diameter; in each pair one well Buryats vertically, and the second drill into the side of a slope of the scarp slope to the sole at such an angle that the inclined borehole crossed estimated LSP in the middle.

Efficiency and intensification of drilling and blasting operations in the proposed method, blasting high ledges is the following. When conventional blasting the upper limit of the height of the drilling and blasting work benches limited technical capabilities of the used drilling equipment, first of all, the maximum possible diameter of the drilling of the existing drilling equipment. In this regard, the maximum possible height of the working ledges from the point of view of their blasting

where H_{max}the ultimate in technical possibilities of drilling equipment the scarp in the case of traditional schemes blasting, m;

D_{m}- the maximum possible for the equipment used drilling diameter m;

γ_{CC}- density loading applied CENTURIES, kg/m^{3};

q is the calculated specific consumption of EXPLOSIVES, kg/m^{3};

With the magnitude of the berm security, m;

α - the angle of slope of the mouth is a, the hail.

Traditional schemes blasting blasting high ledges in open pits based on the proportionality between the energy of borehole charges volume of exploding rocks, in particular high value resistance line explosion on the bench bottom (LSPP) and include mainly the increase in the diameter of the wells. However, the possibility of increasing the diameter of the borehole drilling equipment commercially available at the present time, industry is almost exhausted.

Application of the method of blasting divergent pairs of wells allows you to increase the height abusively and blow job ledges without increasing the diameter of the drilled wells. Based on the conditions of overcoming of each well pair in half of the calculated values of the resistance line on the sole of the diameter of the hole in pairs (d) must be equal to half of the replaceable unit wells, and therefore the upper limit of the height of the ledge will be

where N’_{max}- the maximum possible height of the ledge using the proposed method, blasting, m;

D_{m}- the maximum possible for the equipment used drilling diameter, m;

γ_{CC}- density loading applied CENTURIES, kg/m^{3};

q is the calculated specific consumption of EXPLOSIVES, kg/m^{3};

With the magnitude of the berm security, m;

α - politcos ledge, deg;

H_{max}the ultimate height of the ledge in the case of traditional schemes blasting.

It is desirable, on the basis of achieving the required quality crushing and study the soles of the ledge inclined hole in a pair to drill at such an angle to the sole, so she crossed the clearing resistance line explosion on the bench bottom right in the middle. To overcome half of the line resistance on the soles determine the diameter of the diverging holes (d) in a pair of

where D_{o}- diameter vertical borehole manoseada large diameter, equivalent to the energy used CENTURIES pair of diverging hole charges.

Considering the above angle β slant well paired to the sole of the ledge equal

where H is the height of the ledge, m;

d - diameter of the diverging holes in the pair, m;

q is the calculated specific consumption of EXPLOSIVES, kg/m^{3};

γ_{CC}- density loading of EXPLOSIVES in a borehole, kg/m^{3}.

The effect of increasing performance drilling in the proposed method, breakage occurs due to various changes in drilling speed and volume of drilling when replacing one well of large diameter diverging pair of wells of smaller diameter. Under the terms of preserving the quality crushing when R is szelenyi estimated line resistance on the soles (in half) the diameter of the slant well in divergent pair (d) is equal to d=D_{
o}/2, where D_{o}- diameter borehole charge of large diameter, equivalent to the energy used CENTURIES pair of diverging hole charges.

The total length of drilled wells in the pair (L_{p}) will be

where H is the height of the ledge, m;

β - the angle of inclination of the inclined borehole to the bottom of the ledge, hail.

On the other hand, it is known that the rate of drilling, all other things being equal, varies inversely as the square of the diameter of the hole. Therefore, when drilling in a pair of diameter d=0,5D_{o}drilling speed (V_{1}) will be

where D_{o}- diameter borehole charge of large diameter, equivalent to the energy used CENTURIES pair of diverging hole charges, diameter d=0,5D_{o}m/s;

d - diameter of divergent wells in pairs, equal to d=0,5D_{o}, m Then the total drilling time (excluding set-up operations) will be:

for single wells of large diameter D_{o}

where H is the height of the ledge, m;

V - speed drill (diameter D_{o}m/s,

for a pair of diverging holes with diameters d

where H is the height of the ledge, m;

β - the angle of inclination of the inclined borehole to the bottom of the ledge, hail,

V is the velocity of the Urena with diameter D_{
o}m/S.

We denote the dimensionless part of the last expression through ϕ_{b}- the rate of change of time drilling

where β - the angle of inclination of the inclined borehole to the bottom of the ledge, hail.

From the analysis of this expression shows that at the change of angle (β) slant well paired in the range of 20°<β<90° always will be a reduction in drilling time (0,5<ϕ<1), and, as a consequence, the productivity of this process.

It is expedient when the simultaneous explosion of the explosive charge in pairs diverging wells initiation of charges in a vertical wells producing from their mouth, and charges in inclined wells at both ends of the charge.

The effect of initiation of the explosive impact in this case is the following. Under the proposed order of initiation (blasting) a pair of diverging borehole charge transfer process in the array explosion energy is structured in time so that the explosion inclined wells in the array until the end of the process of detonation of the explosive charge in a vertical well result in a dynamic inner plane of the outcrop, which is the local screening of the compensation area, promoting the destruction of the array under the action of the less energy intensive and more effective the effective tensile stresses, and directed offset destructible array in the direction of the local compensation zone, i.e. along the line LSPP. This is also the idea of pre-primary prefracture array energy of the explosive charge inclined wells, and the final stage of destruction produced by the explosive charge from the vertical hole.

In an inclined borehole due to counter-initiate its charging time full detonation of EXPLOSIVES (t_{NR}) will be

where l_{n}- the length of the charge in an inclined borehole, m;

V_{d}speed of detonation of EXPLOSIVES, m/S.

During this time, the detonation wave will be held in the vertical charge only a portion of its length. Full time physical-chemical transformations in this charge (t_{CC}) will be

where l_{in}- the length of the explosive charge in a vertical borehole, m;

V_{d}speed of detonation of the explosive charge, m/S.

That is, the lag time full detonation of the explosive charge in a vertical borehole with respect to the inclined (Δt) is the lifetime of the dynamic Nude plane (local compensation zone) along the slant well. This time will be

where t_{CC}- time full detonation of the explosive charge in a vertical well with;

t_{NR}- time full decon the tion of the explosive charge in an inclined borehole,
C;

V_{d}speed of detonation of the explosive charge, m/S.

Expressing the quantities involved in this expression, through geometrical parameters thump of hands ledge and slope of its sides and wells, obtain

where H is the height of the ledge, m;

β - the angle of inclination of the inclined borehole to the bottom of the ledge, deg;

α - the angle of slope of the ledge, deg;

With the magnitude of the berm security, m;

V_{d}speed of detonation of the explosive charge, m/S.

Thus, the time (Δt) the existence of dynamic Nude plane formed by the advancing blasting explosive charge in an inclined borehole, is the existence of local compensatory space, causing translation destructible array of state of stress compression stress state of tension, i.e. the destruction of the array is in the form of margin expansion zone under the action of the less energy-intensive tensile stresses. This circumstance creates conditions for increasing the useful life of the explosion energy and increases the size of the field of the controlled crushing.

It is advisable breaking the high ledges to produce pairs of diverging beams of parallel closely spaced wells drilled with the working surface of the ledge in the vertical plane, in which one beam wells are drilling perpendicularly beneath the ve ledge, and the second drill into the side of a slope of the scarp slope to the sole at an angle

where D_{e}the diameter of manoseada equivalent to the energy used CENTURIES inclined beam borehole charges, m;

H - the height of the ledge, m;

q is the calculated specific consumption of EXPLOSIVES, kg/m^{3};

γ_{CC}- density loading CENTURIES, kg/m^{3}.

This firing method is used in cases when the use of explosive energy sold in the array by way of blasting high ledges divergent pairs of wells is not sufficient for a qualitative study soles and a necessary degree of crushing.

The analytical expression that defines the angle β' beam wells to the bottom of the ledge, derived from the conditions of overcoming each beam in a pair of half the magnitude of the estimated line resistance explosion on the sole destructible high ledge.

Application of the method of blasting beams of borehole charges based on the fact that the charges in the beams of the wells located at a distance of 4-6 diameters from each other and exploded at the same time, act as a single flat charge generating in the array plane wave voltages, which, spreading it, attenuates inversely proportional to the distance, i.e. less intensively than in the cylindrical manoseada equal potentialenergy applied CENTURIES. Due to this, the array breed more saturated with the energy of the explosion and is more intense and uniform dispersion at large distances from the charge. Initiation of the explosive charge in the vertical beams of the wells produced in the upper part of the charges, initiation of charges in the slanting beams of the wells with the upper and lower parts of the charges in the wells.

The calculated equivalent beam borehole charges diameter cylindrical manoseada equal to the potential energy of the applied HV and equal towhere d is the diameter of the holes in the beam; n_{with}- the number of wells in the beam. Value LSP (W_{n.c})spanned by the beam hole charges equal towhere 1,15 - effectiveness ratio of the explosion parallel contiguous charges compared to equivalent cylindrical manoseada; W_{o}- overcome LSP when the detonations equivalent cylindrical measuredly; n_{with}- the number of wells (charges) in the beam.

Thus, the replacement of individual wells in divergent pairs borehole charges on bundles of parallel closely spaced wells of smaller diameter retains all the advantages of the proposed method of blasting, but gives additional reserves improve the quality crushing and study the soles of due to the described features of the action ot the IVA parallel contiguous charges.

Preferably vertical and inclined wells of each pair of wells arranged in two parallel vertical planes, remote from one another by a distance equal to 1-2 diameters equivalent to the energy used BB single wells of large diameter.

The proposed location of the vertical and inclined wells in two parallel vertical planes retains all the advantages of the method of blasting high ledges divergent pairs of wells drilled in the same vertical plane, but due to bias on the working platform ledge point of the slant well drilling relative to the point of drilling vertical, you receive the possibility of partial implementation of the effect of the explosion parallel contiguous charges while initiating charges in a pair of divergent wells in parallel planes.

In this case, below the point of intersection of diverging holes in the vertical projection occurs Λ-shaped design charges that while the explosion of the charge operates as a pair of parallel contiguous charges up until the distance between the wells will not exceed 4-6 diameters of the wells. On this site, which is situated in an area with insufficient energy saturation, due to the above-mentioned effect of blasting parallel contiguous ZAR is DAMI significantly increases the energy output in destroying the array with a corresponding increase in the quality of its crushing.

Considering the above given option blasting high ledges should be used in the blasting of large arrays of high fortress.

It is advisable inclined borehole in each pair of wells drilled in two parallel vertical planes, to drill in the direction of the slope of the scarp slope to the sole at an angle

where H is the height of the ledge, m;

the p - capacity of EXPLOSIVES in 1 m wells, kg/m;

q is the calculated specific consumption of EXPLOSIVES, kg/m^{3}.

An analytical expression that defines the angle β_{1}an inclined borehole to the bottom of the ledge, obtained from the following provisions. With the aim of obtaining Λ-shaped design charges a pair of divergent wells are located in two parallel vertical planes, to implement the effect of the explosion parallel contiguous charge inclined borehole, displaced in space in the second parallel plane, Sabouraud with a slope to the bottom of the ledge so that she was crossing in the projection of a vertical well in the point charge in the borehole, and the estimated LSP, overcome cylindrical manoseada large diameter, equivalent to the energy used CENTURIES pair of divergent wells in the middle.

Preferably the inclined beam of wells in each pair diverging beams, probare the data in two parallel vertical planes, to drill into the side of the free surface of the scarp slope to the sole at an angle

where H is the height of the ledge, m;

the p - capacity of EXPLOSIVES in 1 m wells, kg/m;

q is the calculated specific consumption of EXPLOSIVES, kg/m^{3}.

An analytical expression that defines the angle β_{2}based on the following considerations. For a more uniform distribution of the energy of the explosion at the destruction of the strong large-block arrays and use of the explosion effect of contiguous charges for simultaneous detonation of charges in Λ-shaped design of intersecting vertical projection of contiguous wells inclined beam parallel contiguous wells, shifted in space relative to the vertical and in a second parallel plane, Buryats this angle of inclination to the bottom of the ledge that he was crossing in the projection of the vertical beam of contiguous wells located in the first plane is parallel to, the start point charges in the wells of the beam, and the estimated LSP, overcome cylindrical manoseada large diameter equivalent to the energy used CENTURIES pair of divergent beams wells of smaller diameter is exactly in the middle.

Thus, the application for blasting high ledges divergent beams of parallel closely spaced wells, the offset is the R relative to each other at the point of drilling in two vertical parallel planes, retains the main advantages of the proposed method in the conditions of high ledges, but at the same time allows to significantly increase the useful life of the explosion energy in large hard rocks, primarily due to fully maximize the effect of parallel contiguous charges in terms of creating a directional planar wavefront stresses in the direction of overcoming elevated values LSP maintain the required quality crushing.

The invention is illustrated by drawings, where figure 1 shows the traditional scheme blasting a single cylindrical measuredly in wells of large diameter (Prototype).

Figure 2 shows the scheme of blasting high ledge pairs of divergent wells of smaller diameter, drilled in the same vertical plane.

Figure 3 shows a diagram of blasting high ledge pairs of diverging beams of parallel closely spaced wells.

Figure 4 shows a vertical projection option in the conditions of high ledges divergent pairs intersect in the projection of the wells drilled in two parallel vertical planes, remote from each other by a distance equal to 1-2 times the diameter of the borehole, is equivalent to the energy used CENTURIES pair of divergent wells.

Figure 5 shows the vertical projection variant blasting high in tupov divergent pairs intersect in the projection beam parallel contiguous wells, drilled in two parallel vertical planes, remote from each other by a distance equal to 1-2 borehole diameter, equivalent to the energy used CENTURIES pair of divergent beams of closely spaced wells.

Figure 6 shows the volumetric scheme blasting high ledges divergent pairs (beams) intersecting vertical projection of the wells (beams), drilled in two parallel vertical planes.

In the drawings showing: 1 - vertical well of large diameter; 2 - slope bench; 3 - working space; 4-bottom ledge; 5 and 6 is inclined and vertical wells in a pair of divergent wells drilled in the same vertical plane; 7 and 8 - inclined and vertical bundles of parallel closely spaced wells in a pair of diverging beams, drilled in the same vertical plane; 9 and 10 - inclined and vertical wells in the variation of the location of a pair of diverging and intersecting vertical projection of the wells drilled in two vertical parallel planes; 11 and 12 inclined and vertical bundles of parallel closely spaced wells in a variant arrangement of the pair of diverging and intersecting vertical projection of the beam of contiguous wells drilled in two vertical parallel planes; 13 and 14 - vertical parallel planes distant from D. the UGA at a distance of one to two diameters of the wells of large diameter, equivalent to the energy used CENTURIES pair of divergent wells (beams); 15 and 16 - dimensional representation of the inclined and vertical wells (beams parallel contiguous wells) in a pair of diverging and intersecting vertical projection of the wells (beams), drilled in two vertical parallel planes.

H - the height of the ledge; W - LSP; l_{ZAR}- the length of the explosive charge; l_{C}- length of stemming; l_{p}- the value of perebor; α - the angle of slope of the ledge; β - the angle of inclination of inclined wells (beam wells) to the bottom of the ledge; the berm security; - the offset point of the slant well drilling (oblique beam of contiguous wells) relative to the point of drilling vertical wells (vertical beam wells)drilled in parallel vertical planes, l_{PS}- the linear dimension of the area of effect explosion parallel contiguous charges, ↔ - initiation of the explosive charge.

The method is implemented as follows.

Calculates parameters of drilling and blasting works by well-known techniques for real mining conditions traditional blasting high ledges single borehole charges (figure 1).

Determined by calculating the value of the resistance line explosion on the bench bottom W; required diameter borehole charge (manoseada) to overcome the of D_{
o}; the magnitude (length) of the explosive charge l_{ZAR}the value of perebor l_{p}the length of the tamping l_{C}; density loader used BB in the hole γ_{CC}and calculated the specific consumption of EXPLOSIVES q.

Practice drilling and blasting shows that the height of the ledge increasing the value of W, which requires an increase in energy downhole charge and, consequently, increase the diameter of the wells-1. At the same time, limits the increase of the diameter of the wells is limited by the technical capabilities of the existing drilling equipment, in addition, from production drilling and blasting experience it is known that increasing the diameter of the borehole charges - 1 does not provide a significant increase in the quality of crushing and reliable study foot - 4, especially with increasing height of the ledges in a sturdy hard-shot grounds large rocks.

According to the proposed method blasting high ledges (figure 2) single monotherapy in wells of large diameter replace pairs of divergent wells of smaller diameter, one well - 6 paired drilled vertically, the second 5 is drilled in the direction of the slope of the ledge - 2 with an inclination to the base 4 at an angle β.

Based on the conditions of overcoming the explosion of each explosive charge in a pair of wells half of the calculated value of W, inclined well - 5 crosses the line W in the middle. In terms of keeping the necessary degree of fragmentation in the learn the separation settlement W in half the diameter of the diverging wells 5 and 6, a pair define

where D_{o}- diameter vertical borehole unit (manoseada) large diameter (1 - 1), equivalent to the energy used CENTURIES pair of diverging hole charges - 5 and 6.

Considering the above angle β slant well - 5 to the sole of the ledge - 4 is determined from the expression

where H is the height of the ledge, m;

d - diameter of the diverging holes in the pair, m;

γ_{CC}- density loading of EXPLOSIVES in a borehole, kg/m^{3};

q - specific rated BB for a given species and a given quality crushing, kg/m^{3}.

Drilling vertical - 6 and inclined - 5 wells in pairs are produced with a working platform 3 ledge in the vertical plane, perpendicular to the base 4 of the ledge. The distance between the wells in a pair on the working platform is 4-6 d. Place of burial pair of divergent wells on the working platform ledge corresponds to the design position of the individual wells of large diameter (1 in figure 1).

After drilling ledge divergent pairs of wells 5, 6 produce their loading, the militants in vertical wells - 6 set only in the upper part of the charge, and in inclined - 5 - with both ends of the charge. After filling the wells stemming all the militants trigger simultaneously when what emeniem one of the known systems nonelectric initiation (SINV, Nonnal, Dinalog and others).

When this order of initiation (blasting) a pair of diverging borehole charge transfer process in the array explosion energy is structured in time so that the rapid explosion of the explosive charge in an inclined borehole - 5 due to the effect of the counter-initiation in the array until the end of the process of detonation of the explosive charge in a vertical borehole - 6 occurs dynamic inner plane of the outcrop, which is the local screening of the compensation area, promoting the destruction of the array under the action of the less energy intensive and more effective tensile stresses, as well as directed offset destructible array in the direction of the local compensation zone, i.e. along the line LSPP.

This is also the idea of pre-primary prefracture array energy of the explosive charge inclined wells - 5, and the final stage of destruction produced by the explosive charge from the vertical hole - 6.

The lag time full detonation of the explosive charge in a vertical borehole - 6 is the existence of dynamic Nude plane (local compensation zone) along the line of the inclined borehole, causing translation destructible array of state of stress compression stress state of tension, i.e. the destruction of the array is as margin expansion zone under the action of the less energy-intensive tensile stresses. This circumstance creates conditions for increasing the useful life of the explosion energy and increases the size of the field of the controlled crushing, which ultimately reduces the cost of energy of the explosion to reach the necessary degree of fragmentation and, consequently, reduces the specific consumption of EXPLOSIVES.

The effect of reducing the specific consumption of EXPLOSIVES using blasting divergent pairs of wells 5 and 6 receive by reducing cost overruns BB, typical of the traditional method of blasting descending single wells of large diameter (1 - 1). In this case, due to nparalleled vertical wells 6 to the slope - 2 ledge and methodology of calculation of all energy parameters downhole charge on the condition of overcoming the explosion LSP almost the entire volume of the thump of hands borehole charge (1 - figure 1) is destroyed with excessive consumption CENTURIES. From simple geometric constructions and solutions, it follows that K_{B1}characterizing this transition energy is determined from the expression

where W is the estimated value LSP, m;

With the magnitude of the berm security, m

The application of the proposed method in the conditions, when most of the array is destroyed by the explosive charge in an inclined borehole - 5 without loss of power and, as a consequence, RA is turn CC on its destruction,
the value of the coefficient of energy wastage CENTURIES TO_{B2}due to the mismatch between the direction of drilling of wells and the angle of slope - 2 ledge reduced and is (2)

where W is the estimated value LSP, m;

With the magnitude of the berm security, m

always less than 1. This means that when all other conditions being equal, the transition from the conditions of ores and rocks of a single vertical wells of large diameter (1 - 1) to the breaking of their divergent pairs of wells 5 and 6 of smaller diameter in all cases will reduce both specific and absolute consumption CENTURIES. The magnitude of this reduction in each case will depend on the conditions in the conditions and properties of the array.

When the explosion energy sold in the array by way of blasting high ledges pairs of divergent wells, still not enough to study calculated values of W and high-quality crushing, features a rotating drum to produce pairs of diverging beams of parallel closely spaced wells drilled with the working surface of the ledge in the vertical plane (figure 3), in which one beam is 8 wells are drilling perpendicular to the base 4 of the ledge, and the second beam - 7 drill into the side of a slope - 2 bench with a tilt to his sole - 4 at such an angle β’to the inclined beam - 7 parallel is approached wells crossed the calculated value of W in the middle.

The explosive charge in the beams of the wells located at a distance of 4-6 diameters from each other and explode at the same time. In the rock jumper between charges is eliminated in the first moment after the detonation of the charges in the wells of the beam; destroyed the breed is suspended in elastic gases of the explosion, and later formed a unified system of charges works as a single flat charge generating in the vicinity of the beam wells total wave voltage, in the form of approaching flat.

Plane wave voltages, spreading in the array decays inversely proportional to the distance from the charge, i.e. less intensively than in the explosion of the cylindrical equivalent manoseada larger diameter and equal to the potential energy of the applied CENTURIES. In the destructible array more saturated with the energy of the explosion is more intense and uniform dispersion at large distances from the charge.

The calculated equivalent beam borehole charges the equivalent diameter of the cylindrical manoseada equal to the potential energy used BB equalwhere d_{1}- diameter wells in the beam; n_{c}- the number of wells in vertical - 8, and inclined - 7 beams

Limit value of L is p (W_{
n.c})through the beam hole charges without compromising quality crushing, equalwhere 1,15 - effectiveness ratio of the explosion parallel contiguous charges compared to equivalent cylindrical manoseada; Wo - overcoming LSP when blasting equivalent cylindrical manoseada; n_{c}- the number of wells (charges) in the beam.

Thus, the replacement of individual wells in divergent pairs borehole charges for the equivalent energy used CENTURIES bundles of parallel contiguous borehole charges retains all the advantages of the proposed method of blasting, but gives additional reserve increase quality crushing and study the soles of due to the described features of the action of the explosion parallel contiguous charges.

The beams 7 and 8 of divergent wells are drilling with a working platform 3 ledge any known industrial drilling rigs. The distance between the beams (the centers of the beams) on the working platform in the vertical plane of their location is 4-6 D_{e}where D_{e}equivalent beam diameter wells cylindrical manoseada equal to the potential energy of BA, i.e., the diameter of each well in a pair of divergent wells (5 and 6 in figure 2).

Well in the beams 7 and 8 charge applicable explosive fights with the key in the vertical beam - 8 contiguous wells in the upper part of the charges, and inclined beams - 7-from both ends of charges. After operations stemming wells all militants in diverging pairs of beams 7 and 8 trigger at the same time, using one of the known systems nonelectric initiation.

Considering the above angle β′ inclined beam - 7 parallel closely spaced wells to the base 4 of the ledge equal

where D_{e}- equivalent to an inclined beam - 7 wells diameter of the cylindrical manoseada equal to the potential energy used BB, m;

H - the height of the ledge, m;

q is the calculated specific consumption of EXPLOSIVES, kg/m^{3};

γ_{CC}- density loading CENTURIES, kg/m^{3}.

When the breaking of strong large breeds well in divergent pairs are placed in two parallel vertical planes, remote from one another by a distance equal to 1-2 diameters, equivalent in energy of BA single wells of large diameter (figure 4).

A vertical well is drilled at 10 point design on the worksite, 3 shelf, and an inclined hole - 9 Sabouraud in parallel vertical planes offset in the projection (figure 4) point of drilling on site - 3 relative to the point of drilling vertical wells - 10 on-site - 3-size
where l_{3}- the length of the tamping, β_{1}- the angle of slant wells 9 to the base 4 of the ledge.

In this case, below the point of intersection of the diverging pairs of wells 9 and 10 in the vertical projection (figure 4) occurs Λ-shaped design charges, which while detonating charges in a pair of diverging holes (9 and 10) works as a pair of parallel contiguous charges up until the distance between the wells will not exceed 4-6 diameters of the wells. In this area l_{PS}(the linear size of the zone of effect of parallel contiguous charges), located in the zone with insufficient energy saturation, due to the effect of the explosion parallel contiguous charges substantially increases the energy output in destroying the array with a corresponding increase in the quality of crushing.

For drilling wells 9 and 10 apply standard industrial drilling equipment, loading and blasting wells 9 and 10 produced by analogy with the previous described variants of the proposed method in the conditions of high ledges.

An inclined hole 9 in each pair of wells 9 and 10, placed in two parallel vertical planes, drill into the side of a slope - 2 bench with a tilt to his sole - 4 at an angle β_{1}so that the inclined bore 9 in vertical parallel planes offset the traveler relative to the point of drilling vertical wells
10 in another vertical plane is parallel to thecrossed in the projection (figure 4) vertical well 10 at the point of the beginning of the explosive charge in the borehole with the aim of obtaining Λ-shaped design charges a pair of divergent wells 9 and 10, and the estimated LSP (W) in the middle.

Considering the above angle β_{1}slant wells 9 to the base 4 of the ledge

where H is the height of the ledge, m;

the p - capacity of EXPLOSIVES in 1 m wells, kg/m;

q is the calculated specific consumption of EXPLOSIVES, kg/m

Thus, shown in figure 4 layout vertical - 10 and inclined - 9 wells in parallel vertical planes retains all the advantages of the method of blasting high ledges pairs of divergent wells, but due to bias on the working platform 3 ledge point of drilling directional wells - 9 relative to the point of drilling vertical wells - 10, you receive the possibility of partial implementation of the effect of the explosion parallel contiguous charges while initiating charges in a pair of divergent wells 9 and 10 in parallel planes.

Similarly, when the blasting high ledges in a strong and very large rocks to a more uniform saturation energy of the explosion destroyed the ledge serves Ariant method of blasting high ledges pairs of diverging beams parallel contiguous charges, placed in two parallel planes, remote from one another by a distance equal to 1-2 diameters equivalent to the energy used BB single wells of large diameter (figure 5).

Vertical beam - 12 contiguous wells in one of the parallel planes of the Buryats in the clearing mark on the jobsite - 3 bench, inclined beam - 11 contiguous wells Sabouraud in another parallel vertical plane offset mark drilling at site - 3 vertical beam - 12 contiguous wells on the value of “b” in the vertical projection (figure 5), equalwhere l_{3}- the length of the tamping in wells, β_{2}- the angle of the inclined beam parallel closely spaced wells to the base 4 of the ledge.

Inclined beam - 11 contiguous wells in each pair diverging beam 11 and 12 contiguous wells located in parallel vertical planes, drill into the side of a slope of the ledge - 2 with an inclination to the base 4 at an angle β_{2}thus, inclined to the beam 11 in a parallel vertical plane, mark spudding of which on-site - 4 is displaced in the projection (figure 5) relative to the level of drilling at site - 4 vertical beam - 12 contiguous wells in the other parallel to the vertical plane by the value of
crossed in the projection (figure 5) vertical beam - 12 contiguous wells in the starting point of the explosive charge in the beam in order to obtain Λ-shaped design of parallel-contiguous charges, and the estimated LSP (W) crossed in the middle.

Considering the above angle β_{2}inclined beam - 11 contiguous wells to the base 4 of the ledge

where H is the height of the ledge, m;

the p - capacity of EXPLOSIVES in 1 m wells, kg/m;

q is the calculated specific consumption of EXPLOSIVES, kg/m^{3}.

Well in the beams 11 and 12 charge explosive, with militants in contiguous wells vertical beam - 12 in the upper part of the charges, and in wells inclined beam - 11 at both ends of charges. After operations stemming in vertical wells 12 and inclined - beams 11 contiguous wells produce simultaneous initiation of the explosive charge in the beam, using one of the nonelectric initiation systems.

Λ-shaped design of contiguous charges (figure 5) with the simultaneous explosion of the charges in a pair of divergent beams 11 and 12 parallel contiguous wells works on the section l_{PS}(5) as a single system parallel contiguous charges up until the distance between the beams 11 and inclined vertical - 12 contiguous wells will not exceed 4-6 D_{e}where D_{e}- iameter equivalent beam wells cylindrical manoseada equal to the potential energy of the applied CENTURIES.

Figure 6 shows three-dimensional case diagram of the method of blasting high ledges divergent pairs 15 and 16 wells (bundles of closely spaced wells), located in two parallel vertical planes 13 and 14.

Thus, the location of the diverging pairs of beams parallel contiguous hole charges in two vertical parallel planes, owing to the occurrence of Λ-shaped design of contiguous charges in the locality, unregulated crushing effect of the explosion parallel contiguous charges, significantly increase the output energy of the explosion to destroy the array with a corresponding increase in the quality of crushing.

Thus, the proposed method blasting high ledges in open-cast mining by replacing the wells of large diameter divergent pairs of wells (beams parallel contiguous wells) of smaller diameter, equivalent to the energy used CENTURIES the well of large diameter, allows without additional capital expenditure for the acquisition of additional drilling equipment and the updating of assortment of explosives to produce a rotating drum and high ledges to reach the necessary degree of fragmentation and qualitative examination of the soles.

One well (a bunch of contiguous wells) drilled in a pair of vertically and W heaven well (a bunch of contiguous wells) - with a slope to the bottom of the ledge at such an angle that the estimated value LSPP high ledge crossed inclined borehole (angle beam of contiguous wells) in the middle. The distance between the points spudding wells (bundles of closely spaced wells) on-site bench is 4-6 diameter wells (or 4-6 diameter wells, equivalent to the energy used CENTURIES beam of contiguous wells).

For a more uniform distribution of the energy of the explosion suggested accommodation options directional and vertical wells (beams), respectively, in parallel vertical planes.

Efficient drilling and blasting in the proposed method, blasting high ledges in open pits explained not only by the geometry of the explosive charge in pairs diverging wells (bundles of closely spaced wells), which also allows to use the effect of the explosion parallel contiguous charges in areas with insufficient energy saturation of destruction, but rather a way of initiating vertical and inclined charges in pairs diverging wells (bundles of closely spaced wells)to implement targeted and less energy-intensive destruction of the array at line LSP, as well as the effect of increasing the productivity of drilling due to various changes in drilling speed and volume of drilling when replacing the ne wells of large diameter diverging a pair of wells of smaller diameter.

1. The method of blasting rock at surface mines, including drilling down-hole, loading and blasting, characterized in that the blasting of rocks are divergent pairs of wells drilled with the working surface of the ledge in the vertical plane, in which one hole in each pair of wells are drilling perpendicular to the sole of the ledge, and the second in the direction of the slope of the scarp slope to the sole at an angle

H - the height of the ledge, m;

d is the diameter of the hole in a pair of divergent wells, m;

q is the calculated specific consumption of EXPLOSIVES for a given species and a given quality crushing, kg/m^{3};

γ_{CC}- density loading of EXPLOSIVES in a borehole, kg/m^{3}.

2. The method according to claim 1, characterized in that the simultaneous explosion of the explosive charge in a pair of divergent wells initiation of charges in a vertical wells produce from their mouth, and charges in inclined wells at both ends of the charges.

3. The method of blasting rock at surface mines, including drilling down-hole, loading and blasting, characterized in that the breaking of rocks are pairs of diverging beams of parallel closely spaced wells drilled with the working surface of the ledge in the vertical plane, in which one pooch is to wells are drilling perpendicular to the sole of the ledge, and the second beam drill into the side of a slope of the scarp slope to the sole at an angle

where D_{e}- diameter cylindrical manoseada equivalent to the energy used CENTURIES inclined beam borehole charges, m;

H - the height of the ledge, m;

q is the calculated specific consumption of EXPLOSIVES, kg/m^{3};

γ_{CC}- density loading of EXPLOSIVES in a borehole, kg/m^{3}.

4. The method of blasting rock at surface mines, including drilling down-hole, loading and blasting, characterized in that the breaking of lead pairs of divergent wells drilled with the working surface of the ledge in the vertical plane, in which one hole in each pair are drilling perpendicular to the sole of the ledge, and the second in the direction of the slope of the scarp slope to the sole, with vertical and inclined wells of each pair of wells are arranged in parallel vertical planes, remote from each other by a distance equal to 1-2 borehole diameter, equivalent to the energy used CENTURIES pair of divergent wells.

5. The method according to claim 4, characterized in that the inclined hole of each pair of wells drilled at the side of a slope of the scarp slope to the sole at an angle

where H is the height of the ledge, m;

the p - capacity of EXPLOSIVES in 1 m wells, kg/m;

q is the calculated specific consumption of EXPLOSIVES, kg/m^{3}.

6. The method of blasting rock at surface mines, including drilling down-hole, loading and blasting, characterized in that the breaking of rocks are pairs of diverging beams of parallel closely spaced wells drilled with the working surface of the ledge in the vertical plane, in which one beam wells are drilling perpendicular to the sole, and the second in the side of a slope at an angle to the sole, with vertical and oblique beams of each pair of beams are arranged in parallel vertical planes, remote from each other by a distance equal to 1-2 borehole diameter, equivalent to the energy used CENTURIES pair of divergent wells.

7. The method according to claim 6, characterized in that the inclined beam wells in a pair of divergent beams of wells drilled at the side of a slope of the scarp slope to the sole at an angle

where H is the height of the ledge, m;

the p - capacity of EXPLOSIVES in 1 m wells, kg/m;

q is the calculated specific consumption of EXPLOSIVES, kg/m^{3}.

**Same patents:**

FIELD: mining art, in particular, open-pit mining of mineral resources by high benches.

SUBSTANCE: large-diameter single holes are replaced by a pair of divergent holes of a smaller diameter, in which one hole is always vertical, and the other one is inclined towards the bench; the single holes of the larger diameter are replaced with a pair of divergent bundles of parallel converged holes, in which one bundle is vertical, and the other is inclined towards the bench; the single holes of the larger diameter are replaced with a pair of divergent holes of a smaller diameter, in which one hole is vertical, and the other is inclined towards the bench and positioned in the vertical plane parallel with the first one and distant from it by 1-2 hole diameters; the single holes of the larger diameter are replaced by a pair of divergent bundles of parallel converging holes, in which one bundle is vertical, and the other is inclined towards the bench and positioned in the vertical plane parallel with the first one and distant from it by 1-2 hole diameters.

EFFECT: enhanced efficiency of blasting of the benches.

7 cl, 6 dwg