RU2511330C2 - Method for large-scale explosive destruction of mine rock masses of complex structure for selective extraction of mineral deposit at open-pit mining - Google Patents

Abstract

FIELD: blasting operations.

SUBSTANCE: invention refers to mining industry, and namely to open-pit mining operations at development of ore and non-ore blocks of mineral deposits, the sections of which are sufficiently different as to mining-and-geological structure and quality of a valuable component, and namely to selective extraction of a mineral deposit by large-scale explosive destruction of mine rock masses of a complex structure. In rows of charges, which cross different-type mine rocks, well and group beam charges are located; group beam charges are located in sections requiring intense crushing. The latter are located in sections requiring intense crushing with direction of a convex beam surface towards intense crushing; row-by-row explosive breakage of single well and group beam charges is performed, thus performing row-by-row extension of nominal diameter of an explosion cavity.

EFFECT: preserving integrity of geometry of locations of large volumes of mine rocks within their initial geological location before and after large-scale explosions.

2 cl, 3 dwg

Description

The invention relates to the mining industry in open pit mining in the development of ore and non-metallic blocks of mineral deposits, the areas of which differ significantly in mining and geological structure and the quality of the useful component, namely, the selective extraction of minerals by large-scale explosive destruction of mountain ranges of complex structure.

Known methods of multi-row blasting of ledges for excavation by a gross method, which form various types of crushing of rock mass by an explosion, accompanied by movement and mixing of rock mass in the collapse of the ledge, and the width and direction of the excavator's entry ensure the sequence of excavation of minerals [V.V. Rzhevsky. Open pit mining processes. M .: Nedra, 1974, p. L29].

The disadvantage of this method is the impossibility of mining minerals, interspersed with local arbitrary shape and location by sections of rock inside a block of complex structure deposits, without mixing, differing in mining and geological structure and the quality of the useful component of the sites.

There is a method of separate blasting and separate excavation in the development of ore bodies, which includes combined separate blasting, when vertical or deviated wells are located only along the contour, creating a screen, and inside the plot, blasting is carried out by vertical borehole charges with separate blasting into a split trench.

Separate development of complex rock faces is characterized by the use of drilling and blasting operations, which allow changing the nature of rock destruction by regulating the energy distribution in the volume to be destroyed, changing the volumetric energy concentration of explosives and the energy reserve in 1 m of the borehole charge, using directional explosions taking into account the peculiarities of the geological structure [V. N. Mosinets, A.D. Pashkov, V.A. Latyshev. The destruction of rocks. M .: Nedra, 1975].

The disadvantage of this method is that the use of multi-row blasting in complex structural arrays is caused by the obligatory presence of a clamp or uncleared rock mass, the value of which has a calculated value without taking into account changes in the intensity of rock destruction along the width and depth of the block. With this method of blasting, the integrity of the massif is not ensured within its initial geological location. Another drawback is that the use of wells of the same diameter leads to a rapid limitation of the number of blown rows due to the formation of a certain limit in their number, associated with the need to overcome the next series of increasing loads with charges of the same diameter. That is, the increasing load is not compensated by a constant charge energy.

The closest in technical essence and the achieved result is a method of selective extraction of high-quality minerals in a quarry, including drilling wells in accordance with the project of a mass explosion, surveying a block, studying the natural blocking of rocks, contouring high-quality ore, loading wells with explosive, exploding wells and mineral excavation according to the ore mining planogram [Patent for invention No. 2208221, 10/14/1992 Aut. Eremenko A.A., Eismont S.N., Smirnov S.M., Burmin G.M., Ermak G.P. (prototype)].

The disadvantage of this method is the low adaptability, expressed in the need to first determine the location of the formation of the cutting compensation cavities by drilling additional compensation non-rechargeable wells with their reference to the main fracture systems. This method also has the disadvantage of the previously described method of separate breaking and separate excavation in the development of ore bodies, since the diameter of the wells, as in other methods that solve this problem, is not changed.

The aim of the invention is to ensure the preservation of the geometry of the locations of large volumes of the rock mass within their initial geological location before and after a large-scale mass explosion, to achieve a selective degree of crushing during explosion preparation of sections of heterogeneous rocks both in plan and in depth of a complex structural unit using conventional technology in shape, but a large-scale essentially massive explosion in open works, creating conditions for a stable and efficient selective excavation disassembling a complex structural face with a decrease in the number of movements of loading and transport equipment, achieving an almost unlimited multi-row mass explosion, obtaining close to zero displacement of the beaten part of the massif, eliminating the need for clamping in the form of uncleared rock mass by developing and applying new parameters for drilling and blasting operations and combinations of schemes decelerations up to instant blasting of the entire block.

This goal is achieved by the fact that with the method of large-scale explosive destruction of mountain massifs of complex structure for the selective extraction of minerals in open works, a conventional increase in the conditional diameter of the explosive cavity is carried out using beam charges with a variable number of wells in the beam, an increase in the number of wells in each of which, starting with second row, determined from the ratio:

, шт, $$N_i=\frac{nW}{l}$$

, PC,

where N _i is the number of wells in the group beam charge of the i-th row, pcs;

n is the number of the ith row of group beam charges, starting from the second;

W - line of least resistance of downhole charges of the first row, m;

l is the size of the free surface per one borehole charge, and numerically equal to the distance between charges in the first row of wells, m

The volume concentration of the explosion energy of a group beam charge of the ith row or its conditional diameter is changed inversely with the change in the coefficient of loosening of the broken rock mass, determined by the dependence:

, МДж/м³, $$M_{BB}^i=\frac{M_{BB}}{k_p^i}$$

, MJ / m ³ ,

- объемная концентрация энергии взрывчатого вещества i-го ряда групповых пучковых зарядов, МДж/м³;Where $$M_{BB}^i$$

- volumetric concentration of explosive energy of the ith row of group beam charges, MJ / m ³ ;

M _BB - volumetric concentration of explosive energy of the first row of group beam charges, MJ / m ³ ;

- коэффициент разрыхления при взрывании i-го ряда групповых пучковых зарядов. $$k_p^i$$

is the coefficient of loosening during the explosion of the ith row of group beam charges.

 In adjacent group beam charges, both in a row and between them, cumulative charges with a flat symmetry of linear shape are established with the axis of the cumulative recess oriented in the directions of vertical or slightly inclined contacts. In the central wells of group beam charges, cumulative charges with a flat symmetry of a ring shape with the orientation of the axis of the cumulative charge extraction in the directions of horizontal or gentle contacts are set. Short-delayed explosion of group beam charges is carried out, starting from the second and subsequent rows, with an increase in the degree of deceleration of each subsequent row by no less than

, $$\Delta t=\frac{W}{C_{mp}}$$

,

where Δt is the increase in the degree of deceleration, ms;

W _i - line of least resistance of the group beam charge of the i-th row, m;

C _mp - crack growth rate in the rock, m / s.

The last to explode the first-row borehole charges.

The invention is illustrated by drawings, where figure 1 shows the selective extraction of minerals by large-scale explosive destruction of mountain ranges in opencast mining of deposits of complex structure. Figure 2 shows the position of the cumulative charges with a flat symmetry of a linear shape with the opposite location in the extreme wells of group beam charges. Figure 3 shows the location of the cumulative charges with a flat symmetry of a ring shape, established by the contact areas of different types of rocks with the orientation of the axis of the cumulative excavation of the charge in the direction of contacts of different types of rocks.

A method of large-scale explosive destruction of mountain masses of complex structure for selective extraction of minerals in open works involves drilling in an array of 1 rows of single borehole charges 2, bundle borehole charges 3, 4, 5, the number of wells in which increases in proportion to the increase in clamp coefficient, the loading of wells 6 and 7 standard and conversion explosives with a variable volume concentration of energy, the formation of combined charges 8 with a variable energy supply in their lower part, installation in neighboring x group beam charges both in a row and between them of counter cumulative charges 9 with flat symmetry, installation of group beam charges of cumulative charges 10 with flat symmetry of a ring shape in the central wells with orientation of the axis of cumulative excavation in the directions of horizontal or gentle contacts 11 of ore 12 and rocks 13, short-blown blasting of borehole charges, starting from the second and subsequent rows with an increase in the degree of deceleration of each subsequent row.

The method is implemented as follows (figure 1).

. В зависимости от характеристик горных пород, зависящих от взрываемости, величина $$\frac{W}{l}$$

принимает значение от 0,7 до 1,5.In the complex structural rock mass 1, an orderly explosive blasting is performed to clamp single borehole charges 2 using group beam charges 3, 4, 5, the number of which in the next row increases depending on the parameters of the blasting. To do this, in each group beam charge of the subsequent, starting from the second row, an increase in the number of wells is determined, determined from the ratio $$N_i=\frac{nW}{l}$$

. Depending on the characteristics of the rocks, depending on the explosiveness, the value $$\frac{W}{l}$$

takes a value from 0.7 to 1.5.

.With a non-integral number of wells in a group beam charge, rounding is performed. The volume concentration of the explosion energy of the group beam charge of wells 6 and 7 changes inversely with the change in the coefficient of loosening of the borehole charges according to $$M_{BB}^i=\frac{M_{BB}}{k_p^i}$$

.

. Главное отличие от техники подобных взрывных работ заключается в количестве взрываемых рядов, которое в обычной практике ограничивается небольшим их количеством, лимитированным возможностями и энергией взрыва одиночного скважинного заряда 2, принятого, исходя из технических возможностей буровой техники, диаметра. В новой технологии ограничение по энергии количества последующих слоев скважинных зарядов, обусловленное (лимитированное) возможностями буровой техники, в принципе отсутствует.Thus, an increase in the load on each of them due to an increase in the increasing general effect of clamping deeper into the blasting block is compensated by an increase in the energy of charges in subsequent rows. Additional compensation for the load on the borehole charges is realized by creating 8 combined, along with the length of charges, powerful explosives, including conversion explosives. The energy reserve in the lower part of the charges is determined by the dependence $$Q_{BB}^i=\frac{\mathrm{<figure-callout\; id="2"\; label="\pi \; d"\; filenames="00000018.png"\; state="\{\{state\}\}">\pi \; </figure-callout>}{d}^{}{}^{2}0.6W_{i}n{M}_{BB}^i}{\mathrm{four}{k}_p^i}$$

. The main difference from the technique of such blasting is the number of rows exploded, which in normal practice is limited to a small number of them, limited by the capabilities and energy of the explosion of a single borehole charge 2, adopted on the basis of the technical capabilities of the drilling equipment, diameter. In the new technology, the energy limit of the number of subsequent layers of borehole charges, due to (limited) capabilities of drilling equipment, is in principle absent.

The formation of local sections of the rock mass of ore and rock (Fig. 2), not mixed by an explosion on a ledge and in terms of camber height comparable with the height of the ledge before an explosion, is carried out by installing 9 s in adjacent group beam charges both in a row and between rows of cumulative charges flat symmetry of a linear shape located in the directions of vertical or slightly inclined contacts and towards each other in the wells of beam charges. Cumulative charges 10 with a flat ring-shaped symmetry (Fig. 3) are placed at the contact 13 of ore 11 and rock 12 with the orientation of the axis of the cumulative recess in the directions of horizontal or gentle contacts.

In the rows of charges crossing different types of rocks, there are borehole and group beam charges, and group beam charges are located in areas requiring enhanced crushing with the direction of the convex surface of the group beam charge in the direction of the section of enhanced crushing.

Thus, in adjacent borehole and group beam charges, cumulative charges with a flat symmetry of a linear shape with orientation of the axis of the cumulative excavation in the directions of vertical or slightly inclined contacts are installed both in a row and between them;

- in borehole and central wells of group beam charges, cumulative charges with a flat symmetry of a ring shape are established with the orientation of the axis of the cumulative charge extraction in the directions of horizontal or gentle contacts;

- blasting of charges begins with the simultaneous detonation of cumulative charges, then with a short-blown blasting of subsequent rows, starting from the second, and with an increase in the degree of deceleration of each subsequent row by no less than

, $$\Delta t=\frac{W}{C_{mp}}$$

,

where Δt is the increase in the degree of deceleration, ms;

W _i - line of least resistance to the beam charge of the i-series, m;

C _mp - crack growth rate in the rock, m / s.

.The last to explode the borehole charges of the first row. By combining blasting retardation schemes, including instant camouflage, the degree of preservation of the geometry of the location of the destroyed rock mass up to the state of zero degree of displacement to the original is achieved, which creates favorable conditions for the selective excavator disassembly of complex structural face, significantly increasing its efficiency. To obtain such a degree of displacement of part of the massif and to eliminate the need to use uncleaned rock mass when blasting the first row, first explode group beam charges 3 and subsequent rows 4 and 5 with an increase in the deceleration rate of each subsequent row by no less than $$\Delta t=\frac{W}{C_{mp}}$$

.

Claims (2)

1. A method of large-scale explosive destruction of mountain ranges of complex structure for the selective extraction of minerals in open works, including the use of natural blocking and disturbance of rocks, contouring of high-quality ore, drilling of blast holes, their loading with explosive compositions, blasting according to the schemes and parameters of drilling and blasting operations in accordance with with the project of a mass explosion and excavation of minerals according to the planogram of ore mining. characterized in that in the complex structural mountain Hydrogens with the intersection of their types of different types have single borehole and group bunch charges in rows, the latter being located in areas requiring enhanced crushing with the convex surface of the beam directed towards enhanced crushing, they make an orderly explosive breaking of single borehole and group beam charges into a clamp, performing an orderly expanding the nominal diameter of the blast cavity, for which they increase the number of wells in each subsequent beam, starting from the second, row and divide the number of downhole beam charges in the beam of the i-th row from the ratio:
$$N_i=\frac{nW}{l}$$

, PC,
where N _i is the number of wells in the group beam charge of the i-th row, pcs;
n is the number of the i-th row of downhole beam charges, starting from the second;
W - line of least resistance of downhole charges of the first row, m;
l is the size of the free surface per one borehole charge, and numerically equal to the distance between charges in the first row of wells, m;
depending on rock characteristics $$\frac{W}{l}$$

takes a value from 0.7 to 1.5;
the volumetric energy concentration of the explosion of the borehole beam charge of the i-th row or its nominal diameter is changed inversely with the change in the coefficient of loosening of the broken rock mass according to:
$$M_{BB}^i=\frac{M_{BB}}{k_p^i}$$

, MJ / m ³ ,
Where $$M_{BB}^i$$

- volumetric concentration of explosive energy of the ith row of group beam charges, MJ / m ³ ;
M _BB is the volumetric concentration of explosive energy of the 1st row of group beam charges, MJ / m ³ ;
$$k_p^i$$

- coefficient of loosening during explosions of the ith row of group beam charges;
moreover, in adjacent group beam charges both in a row and between rows, cumulative charges with a flat symmetry of a linear shape are established with the axis of the cumulative recess oriented in the directions of vertical or slightly inclined contacts, in the central wells of group beam charges, cumulative charges with a flat ring symmetry and by orienting the axis of the cumulative recess of the charge in the directions of horizontal or gentle contacts, a short-delayed explosion of charges is carried out starting from the second o and subsequent rows with the increase in the deceleration stage of each subsequent row by an amount not less than Δt:
$$\Delta t=\frac{W_{\iota }}{C_{mp}}$$

,
where Δt is the increase in the degree of deceleration, ms;
W _i - line of least resistance of the group beam charge of the i-th row, m;
C _mp - crack growth rate in the rock, m / s;
and the last to explode the borehole charges of the first row. 2. The method of large-scale explosive destruction of mountain massifs of complex structure for the selective extraction of minerals in opencast mining according to claim 1, characterized in that the additional compensation of the load on the charges is carried out by creating powerful lengthwise combined charges, including conversion, explosives whose energy reserve in the lower part is determined by the formula:
$$Q_{BB}^i=\frac{\pi d^{2}0.6W_{i}n{M}_{BB}^i}{\mathrm{four}{k}_p^i}$$

, MJ,
Where $$Q_{BB}^i$$

- energy reserve of the lower part of the ith row of group beam charges, MJ;
$$k_p^i$$

- coefficient of loosening during explosions of the ith row of group beam charges;
d is the diameter of the wells in the group beam charge of the i-th row, m;
W _i - line of least resistance of the group beam charge of the i-th row, m;
$$M_{BB}^i$$

- volumetric concentration of explosive energy of the ith row of group beam borehole charges, MJ / m ³ ;
n is the number of wells in the group beam charge of the i-th row.

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