RU2499222C1 - Method of exploding different-strength rocks - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: proposed method comprises drilling of vertical wells and reaming them inside the outline of soli inclusions at appropriate cross points. Note here that diameter of well reamed sections $$d_0^{inc}$$

is taken with allowance for diameter of nonreamed wells $$d_0^b,$$

ultimate strength $${\sigma }_{ul}^{inc}$$

and $${\sigma }_{ul}^b$$

and Poisson's ratios ν^inc and ν^b, modulus of elasticity E^inc and E^b, porosity "П"_inc and "П"_b, solid inclusions and bearing strata, respectively, isentropic curve of detonation products γ₂, parameter of adiabatic curve ξ, and pressure of detonation products at Chapman-Jouguet point P₀ of used industrial explosive.

EFFECT: efficient and uniform fracturing.

1 tbl

Description

The invention relates to mining and construction, and in particular to methods of blasting rock masses of different strengths in open cast mining. Such massifs may have inclusions represented by interlayers, layers (layers) of hard rocks in the enclosing less strong rocks, various lenses and other formations having different positions and power along the height of the blasting block.

A known method of blasting rock of various strengths with solid inclusions in open pit mining, including drilling vertical wells, loading them with combined charges of industrial explosives (PWS), blocking wells and blasting PW charges. Moreover, a more powerful PVV is placed in that part of the charges that crosses the solid inclusion [1].

The known method does not guarantee the required quality of crushing of multi-strength arrays, since it does not take into account the totality of the basic properties of the host rocks, inclusions and applied PVV.

In addition, the possibility of using the method is limited by the need for several types of PVV at the enterprise with significantly different properties. This can cause significant difficulties, especially with a small amount of consumption of more powerful PVV required for crushing solid inclusions, which limits the scope of the method.

The closest technical solution to the claimed one is a method of blasting rock masses of various strengths with solid inclusions in opencast mining, including determining the presence of solid inclusions in the host rocks, the contour in plan and marks of the roof and soil of these inclusions, drilling vertical wells, expanding wells at the intersection sites solid inclusions, loading wells with explosive charges, the diameter of which is equal to the diameter of the wells, and blasting explosive charges [2]. The method has been widely used in thermal drilling and expansion of wells drilled by mechanical methods in thermobored rocks (unoxidized ferruginous quartzites, strong and dense quartzites, granites and some other rocks). At the same time, the strength properties of the host rocks and stronger inclusions differed no more than 1.5 times. Currently, in world practice, including in the Russian Federation, thermal drilling and expansion of wells are used extremely rarely due to its high cost and selectivity.

The specified method does not guarantee obtaining the required quality of crushing of multi-strength arrays, since it does not take into account the totality of the basic properties of the host rocks, inclusions and the applied UIP. As a result of this, equality of the diameters of the zones of controlled crushing (SAM) in the enclosing less strong rocks and stronger inclusions is not ensured, which reduces the efficiency and uniformity of crushing of multi-strength arrays.

The objective of the invention is to improve the quality of crushing of different-strength rock masses with solid inclusions having different positions and power along the height of the blasted block.

The technical result achieved in this case is to increase the efficiency and uniformity of crushing of multi-strength arrays by ensuring the equality of the diameters of the zones of controlled crushing in the host rocks and solid inclusions by taking into account the totality of the basic properties of the host rocks, inclusions and the applied UIP.

расширяемых участков скважин принимают из соотношения:The specified technical result is achieved by the fact that in the known method of blasting rock masses of various strengths with solid inclusions in open cast mining, which includes determining the presence of solid inclusions in enclosing less strong rocks, the contour in plan and marks of the roof and soil of these inclusions, drilling vertical wells, expanding wells in areas where they intersect solid inclusions, loading wells with charges of industrial explosives (IAP), the diameter of which is equal to the diameter of the wells, and blasting the charges of PV According to the invention the pre-defined limits of the tensile strength, Poisson's ratio, Young's modulus, porosity and bulk coefficients host rocks and solids, while the diameter $$d_0^{\mathrm{at}\mathrm{to}l}$$

expandable sections of wells are taken from the ratio:

$$d_0^{\mathrm{at}\mathrm{to}l}=d_0^{\mathrm{at}m}\sqrt{\left(\frac{{\left(\frac{\zeta \cdot P_0}{{\sigma }_{R\mathrm{but}\mathrm{from}}^{\mathrm{at}m}}\right)}^{\frac{\mathrm{one}}{{\gamma }_2}}-\mathrm{one}+\frac{{\sigma }_{R\mathrm{but}\mathrm{from}}^{\mathrm{at}m}}{K_{\mathrm{at}m}}}{{\left(\frac{\zeta \cdot P_0}{{\sigma }_{R\mathrm{but}\mathrm{from}}^{\mathrm{at}\mathrm{to}l}}\right)}^{\frac{\mathrm{one}}{{\gamma }_2}}-\mathrm{one}+\frac{{\sigma }_{R\mathrm{but}\mathrm{from}}^{\mathrm{at}\mathrm{to}l}}{K_{\mathrm{at}m}}}\right)\cdot \left(\frac{\frac{{\sigma }_{R\mathrm{but}\mathrm{from}}^{\mathrm{at}\mathrm{to}l}}{K_{\mathrm{at}\mathrm{to}l}}+M_{\mathrm{at}\mathrm{to}l}+P_{\mathrm{at}\mathrm{to}l}}{\frac{{\sigma }_{R\mathrm{but}\mathrm{from}}^{\mathrm{at}m}}{K_{\mathrm{at}m}}+M_{\mathrm{at}m}+P_{\mathrm{at}m}}\right)}\left(\mathrm{one}\right)$$

- диаметр нерасширенных участков скважин, м; ζ - параметр адиабаты; P₀ - давление продуктов детонации в точке Жуге, Па; γ₂ - показатель изоэнтропы продуктов детонации ПВВ; $${\sigma }_{рас}^{вкл}$$

и $${\sigma }_{рас}^{вм}$$

- соответственно пределы прочности твердых включении и вмещающих пород при растяжении, Па; K_вкл и К_вм - соответственно коэффициенты всестороннего сжатия твердых включений и вмещающих пород; П_вкл и П_вм - соответственно пористость твердых включений и вмещающих пород; $${\text{M}}_{\text{вм}}=\text{2}\left(\frac{{\text{σ}}_{\text{рас}}^{\text{вм}}\left(\text{1}+{\text{ν}}^{\text{вм}}\right)}{{\text{E}}^{\text{вм}}}\right)+{\left[\frac{{\text{σ}}_{\text{рас}}^{\text{вм}}\left(\text{1}+{\text{ν}}^{\text{вм}}\right)}{{\text{E}}^{\text{вм}}}\right]}^2$$

- коэффициент, определяющий упругое расширение границы камуфлетной полости во вмещающих породах; $${\text{M}}_{\text{вкл}}=\text{2}\left(\frac{{\text{σ}}_{\text{рас}}^{\text{вrкл}}\left(\text{1}+{\text{ν}}^{\text{вкл}}\right)}{{\text{E}}^{\text{вкл}}}\right)+{\left[\frac{{\text{σ}}_{\text{рас}}^{\text{вкл}}\left(\text{1}+{\text{ν}}^{\text{вкл}}\right)}{{\text{E}}^{\text{вкл}}}\right]}^{\text{2}}$$

- коэффициент, определяющий упругое расширение границы камуфлетной полости в твердых включениях; ν^вкл и ν^вм - соответственно коэффициенты Пуассона твердых включений и вмещающих пород; Е^вкл и Е^вм - соответственно модуль Юнга твердых включений и вмещающих пород, Па;Where $$d_0^{\mathrm{at}m}$$

- diameter of unexpanded sections of wells, m; ζ is the adiabatic parameter; P ₀ - pressure of detonation products at the Jouguet point, Pa; γ ₂ is an indicator of the isentropic detonation products of PVV; $${\sigma }_{R\mathrm{but}\mathrm{from}}^{\mathrm{at}\mathrm{to}l}$$

and $${\sigma }_{R\mathrm{but}\mathrm{from}}^{\mathrm{at}m}$$

- respectively, the tensile strengths of solid inclusion and host rocks in tension, Pa; K _on and K _vm - respectively, the coefficients of comprehensive compression of solid inclusions and host rocks; P _on and P _vm - respectively, the porosity of solid inclusions and host rocks; $${\text{M}}_{\text{vm}}=\text{2}\left(\frac{{\text{σ}}_{\text{races}}^{\text{vm}}\left(\text{one}+{\text{ν}}^{\text{vm}}\right)}{{\text{E}}^{\text{vm}}}\right)+{\left[\frac{{\text{σ}}_{\text{races}}^{\text{vm}}\left(\text{one}+{\text{ν}}^{\text{vm}}\right)}{{\text{E}}^{\text{vm}}}\right]}^2$$

- coefficient determining the elastic expansion of the boundary of the camouflage cavity in the host rocks; $${\text{M}}_{\text{on}}=\text{2}\left(\frac{{\text{σ}}_{\text{races}}^{\text{on}}\left(\text{one}+{\text{ν}}^{\text{on}}\right)}{{\text{E}}^{\text{on}}}\right)+{\left[\frac{{\text{σ}}_{\text{races}}^{\text{on}}\left(\text{one}+{\text{ν}}^{\text{on}}\right)}{{\text{E}}^{\text{on}}}\right]}^{\text{2}}$$

- coefficient determining the elastic expansion of the boundary of the camouflage cavity in solid inclusions; ν ^on and ν ^vm are Poisson's ratios of solid inclusions and host rocks, respectively; E ^on and E ^VM - respectively, Young's modulus of solid inclusions and host rocks, Pa;

The set of features indicated in the claims includes all the features, each of which is necessary, and all together are sufficient to obtain a technical result.

The distance between the blast holes is usually chosen from the condition of contact of the SAM during the explosions of the explosive charge in these wells. However, when blasting rock masses of different strengths, the diameters of the rocket charge of the borehole charges crossing solid inclusions are significantly smaller within the inclusions than in enclosing less strong rocks. Therefore, in solid inclusions between wells, central zones non-destroyed by explosion are formed. To crush these undestructed zones, the proposed method provides for the expansion of wells in areas where they intersect solid inclusions. This allows you to place a larger number of PVV inside the inclusions and thereby increase the diameter of the air SAM within the inclusions and reduce the volume of these central zones not destroyed by the explosion.

The determination of the presence of solid inclusions in the enclosing less strong rocks, the contour in the plan and the marks of the roof and soil of these inclusions allows you to set the parameters of occurrence of inclusions inside the destructible massif, including their thickness along the depth of specific wells, adjust the design and parameters of the UHV borehole charges, and the necessary expansion sites by the depth of the wells.

Wells are drilled vertically, since such wells are more stable than inclined in rocks of small strength, which in most cases are the host rocks of the massif.

Charging wells with PVV charges, the diameter of which is equal to the diameter of the wells, allows you to simplify the loading process, maximize the use of the volume of wells and increase the yield of rock mass from one linear meter of the well.

Formula (1) is obtained from the condition of ensuring equal diameters of the SAM in the enclosing rocks and inclusions and is based on a ratio that determines the radius of the zone of controlled crushing when taking into account the basic properties of rocks and PW [3]. This ratio for the radius r of the SAM in porous rocks can be rewritten in the form

$$r=r_0\sqrt{\frac{{\left(\frac{\zeta \cdot P_0}{{\sigma }_{R\mathrm{but}\mathrm{from}}}\right)}^{\frac{\mathrm{one}}{{\gamma }_2}}-\mathrm{one}+\frac{{\sigma }_{R\mathrm{but}\mathrm{from}}}{K}}{\frac{{\sigma }_{R\mathrm{but}\mathrm{from}}}{K}+M+P}}$$

where r ₀ is the radius of the well. Then the condition for the equality of the radii (diameters) of the SAM in the enclosing rocks r ^vm and in inclusions r ^{on is} written in the form

r ^vm = r ^on

Formula (1) directly follows from this condition.

It is known that tensile stresses are decisive in the destruction of rocks, since the tensile strength on average is 2.5 times less than with shear, and 10 times less than with compression. A preliminary determination of tensile strengths σ _races , Poisson's ratios ν, Young's moduli E and porosities 77 of the host rocks and solids included in formula (1) is a prerequisite for the implementation of the method, since the diameter of the air defense system depends on the values of these parameters and, therefore, , diameter of expandable sections of wells. The pressure P ₀ of detonation products at the Jouguet point, the adiabatic parameter ζ, and the isoentropic index γ ₂ are constant and known values for each specific PVW at its specific initial density at the moment of charge initiation, i.e., the charge density, and their values, all other things being equal, determine completely diameter of SAM

на участках пересечения ими твердых включений из условия обеспечения равенства диаметров ЗРД во всем взрываемом массиве путем учета совокупности основных свойств вмещающих пород, включений и применяемого ПВВ, что повышает эффективность и равномерность дробления равнопрочных массивов горных пород с твердыми включениями на открытых горных работах.Thus, expression (1) allows you to set the required diameter of the expansion of wells $$d_0^{\mathrm{at}\mathrm{to}l}$$

at the sites of intersection of solid inclusions from the condition of ensuring equal diameters of the SAM in the entire blasted mass by taking into account the totality of the basic properties of the enclosing rocks, inclusions, and the applied explosives, which increases the efficiency and uniformity of crushing of equal-strength rock masses with solid inclusions in open mining.

In view of the foregoing, the totality of all the features indicated in the claims really allows to solve the problem of the invention (improving the quality of crushing) and ensures the achievement of the specified technical result.

The method is carried out by sequentially performing the following operations.

и $${\sigma }_{рас}^{вм}$$

, коэффициенты Пуассона ν^вкл и ν^вм, модули Юнга Е^вкл и Е^вм а также коэффициенты всестороннего сжатия K_вкл, K_вм и пористости П_вкл, П_вм твердых включений и вмещающих пород соответственно.According to the geological service of the enterprise (the results of preliminary engineering and geological exploration), the presence of solid inclusions in the host less strong rocks in the block being prepared for blasting, the contour in the plan and the marks of the roof and soil of these inclusions, their power, and tensile strengths are determined $${\sigma }_{R\mathrm{but}\mathrm{from}}^{\mathrm{at}\mathrm{to}l}$$

and $${\sigma }_{R\mathrm{but}\mathrm{from}}^{\mathrm{at}m}$$

, Poisson's ratios ν ^on and ν ^vm , Young's moduli E ^on and E ^vm as well as all-round compression coefficients K _on , K _vm and porosity P _on , P _{vm of} solid inclusions and host rocks, respectively.

), без учета наличия включений.Taking into account specific conditions, the parameters of vertical borehole explosive charges, including their diameter (borehole diameter), are determined by well-known methods or the results of previous explosions under similar conditions $$d_0^{\mathrm{at}m}$$

), excluding the presence of inclusions.

For the adopted PVV, the detonation parameter γ ₂ , the adiabatic parameter ζ, and the pressure of the detonation products at the Jouguet point P _{0 are} found from the tabular data or well-known dependences.

по принятой на данном предприятии сетке скважин.In accordance with the found resistance values along the bottom of the ledge and the length (depth) of the wells, blast holes are drilled with a diameter $$d_0^{\mathrm{at}m}$$

according to the grid of wells accepted at this enterprise.

и $${\sigma }_{рас}^{вм}$$

, коэффициенты Пуассона ν^вкл и ν^вм, модули Юнга Е^вкл и Е^вм и пористости П_вкл и П_вм твердых включений и вмещающих пород соответственно.In the process of drilling wells, by changing the drilling speed, color and condition of the fracture products that are discharged to the surface, they determine, if necessary, the presence, contour in plan, elevation of the roof and soil and the power of solid inclusions along the depth of each well, as well as tensile strength $${\sigma }_{R\mathrm{but}\mathrm{from}}^{\mathrm{at}\mathrm{to}l}$$

and $${\sigma }_{R\mathrm{but}\mathrm{from}}^{\mathrm{at}m}$$

, Poisson's ratios ν ^on and ν ^vm , Young's moduli E ^on and E ^vm and porosity P _on and P _{vm of} solid inclusions and host rocks, respectively.

и $${\sigma }_{рас}^{вм}$$

, ν^вкл и ν^вм, Е^вкл и Е^вм, П_вкл и П_вм, γ₂, P₀ и принятый диаметр бурения скважин $$d_0^{вм}$$

, определяют диаметр $$d_0^{вкл}$$

расширяемых участков скважин в местах пересечения ими твердых включений, обеспечивающий равенство диаметров ЗРД во вмещающих породах и твердых включениях.Next, using the found parameter values $${\sigma }_{R\mathrm{but}\mathrm{from}}^{\mathrm{at}\mathrm{to}l}$$

and $${\sigma }_{R\mathrm{but}\mathrm{from}}^{\mathrm{at}m}$$

, ν ^on and ν ^vm , E ^on and E ^vm , P _on and P _vm , γ ₂ , P ₀ and the accepted diameter of well drilling $$d_0^{\mathrm{at}m}$$

determine the diameter $$d_0^{\mathrm{at}\mathrm{to}l}$$

expandable sections of wells at the intersection of solid inclusions, ensuring equal diameters of the SAM in the host rocks and solid inclusions.

. Расширение скважин осуществляют одним из известных способов, подходящим для условий конкретного предприятия, параметров залегания твердых включений, свойств вмещающих пород и твердых включений, например с использованием механических расширителей или простреливания небольшими зарядами ПВВ. Расширение скважин может производиться только на полную мощность включений, несколько выше кровли включений и их почвы, от кровли включений и ниже их почвы, ниже кровли включений и до или ниже их почвы. Схема расположения и длина расширяемых участков скважин также будут определяться конкретными условиями взрывания.After that, at the intersections of the wells with solid inclusions, the wells are expanded to the found diameter $$d_0^{\mathrm{at}\mathrm{to}l}$$

. The expansion of the wells is carried out by one of the known methods suitable for the conditions of a particular enterprise, the parameters of occurrence of solid inclusions, the properties of the enclosing rocks and solid inclusions, for example, using mechanical expanders or shooting small explosive charges. Wells can be expanded only at the full capacity of inclusions, slightly higher than the roof of inclusions and their soil, from the roof of inclusions and below their soil, below the roof of inclusions and to or below their soil. The layout and length of the expandable sections of the wells will also be determined by the specific conditions of the blasting.

Then the wells are charged with charges of the same PVV, the diameter of which is equal to the diameter of the wells. In the process of loading the wells, the installation of downhole blasting networks is carried out, and at the end of the loading, the clogging of the upper uncharged part of the wells is performed.

After the end of the stemming of the wells, the surface blast network is installed, connected to the downhole blast networks, and the blast hole explosives are blown up using one of the blasting methods adopted in open pit mining.

An example of the method

, коэффициентом Пуассона ν^вм=0,2 и модулем Юнга E^вм=1,5·10¹⁰ Па. Внутри этих вмещающих пород залегают твердые включения гравелитов, имеющих большую сопротивляемость взрыванию, с коэффициентом крепости по шкале М.М. Протодъяконова ƒ=4…5, средними пределом прочности при растяжении $${\sigma }_{рас}^{вкл}=\mathrm{1,5}\cdot {10}^{10}Па$$

, коэффициентом Пуассона ν^вкл=0,3 и модулем Юнга Е^вкл=4·10³ Па. В качестве ПВВ использовали граммонит М, который при плотности заряжания 1·10³ кг/м имеет показатель изоэнтропы продуктов детонации γ₂=1,26 и давление продуктов детонации в точке Жуге P₀=4,21·10⁹ Па. Высота уступа равнялась 12 м.Overburden rock was blasted at a quarry developing a phosphorite deposit. The rocks of the deposit are composed of sandy loam and loam, pebble and conglomerate, bentonite clays and clay marl, requiring explosive loosening, with a coefficient of strength on the MM scale Protodyakonova ƒ = 1,5 ... 2, average tensile strength $${\sigma }_{R\mathrm{but}\mathrm{from}}^{\mathrm{at}m}=\mathrm{1,5}\cdot 10{}^{6}P\mathrm{but}$$

, Poisson's ratio ν ^VM = 0.2 and Young's modulus E ^VM = 1.5 · 10 ¹⁰ Pa. Inside these enclosing rocks there are solid inclusions of gravelites having a high resistance to explosion, with a coefficient of strength on the MM scale. Protodyakonova ƒ = 4 ... 5, average tensile strength $${\sigma }_{R\mathrm{but}\mathrm{from}}^{\mathrm{at}\mathrm{to}l}=\mathrm{1,5}\cdot {10}^{10}P\mathrm{but}$$

, Poisson's ratio ν ^on = 0.3 and Young's modulus E ^on = 4 · 10 ³ Pa. Grammonite M was used as PVV, which at a loading density of 1 · 10 ³ kg / m has an isentropic index of detonation products γ ₂ = 1.26 and the pressure of the detonation products at the Jouguet point P ₀ = 4.21 · 10 ⁹ Pa. The height of the ledge was 12 m.

, равный диаметру заряда, составлял 250 мм (станок шарошечного бурения СБШ-250 МП с коронкой диаметром 244 мм). Направление скважин - вертикальное. Удельный расход ПВВ - 0,83 кг/м³. Вместимость 1 погонного метра скважины - 31,2 кг/м, форма сетки скважин - квадратная (6×6 м); глубина скважин l_скв - 13,0 м; длина забойки l_заб - 5,0 м; длина перебура l_пер -1 м; длина заряда l_зар - 8 м; масса заряда в скважине - 392 кг.For specific conditions and from the experience of the enterprise without taking into account the presence of solid inclusions, the diameter of the wells $$d_0^{\mathrm{at}m}$$

equal to the diameter of the charge was 250 mm (a cone drilling machine SBSh-250 MP with a crown with a diameter of 244 mm). The direction of the wells is vertical. The specific consumption of PVV is 0.83 kg / m ³ . The capacity of 1 running meter of the well is 31.2 kg / m, the shape of the grid of wells is square (6 × 6 m); well depth l _borehole - 13.0 m; _stemming length l _zab - 5.0 m; the length of the crossbar l _per -1 m; charge length l _zar - 8 m; the charge mass in the well is 392 kg.

, ν^вкл и Е^вкл.Previously, for the block being prepared for the blast, the geological service of the enterprise found that in the host rocks (gypsum clays), a horizontal interlayer of gravelites with a thickness of 4 m with roof marks along the ledge of 6 m and soil 10 m with the above values $${\sigma }_R^{\mathrm{at}\mathrm{to}l}$$

, ν ^on and E ^on

In the course of drilling, changes in the drilling speed, color and condition of the fractured products being released to the surface confirmed the presence, contour in plan, elevation of the roof and soil, thickness and properties of the gravelite layer, as well as the properties of the enclosed gypsum clays, which indicated the need for expansion of the wells over the entire area of the block.

Particular difficulty in the development of the deposit is caused by areas with strong inclusions of conglomerates, gravelites in calcareous cement in soft rocks. Physico-mechanical properties of the rocks are presented in table 1.

Table 1 Breeds: Tensile strength σ _ra , Pa Elastic modulus E, Pa Poisson's ratio ν Rock strength coefficient according to Protodyakonov f Compression coefficient K, Pa Porosity P,% Host rocks (gypsum clay): 1.5 · 10 ⁶ 1.5 · 10 ¹⁰ 0.2 1,5 0.83310 ¹⁰ 13 Strong inclusions (gravelites) 4,510 ⁶ 4.0 · 10 ¹⁰ 0.3 4,5 3.33310 ¹⁰ eleven

When calculating the radii of controlled crushing for enclosing rocks and solid inclusions using grammonite-M (detonation velocity D = 4 · 10 ³ m / s, Δ = 1 · 10 ³ kg / m ³ ), the following values were obtained:

r ₁ = 3.27 m, r ₂ = 2.28 m.

:To increase r ₂ to r ₁ by the relation (1), the required diameter for the expandable sections of the wells, in solid mounts, is determined $$d_0^{\mathrm{at}\mathrm{to}l}$$

:

, $${\text{M}}_{\text{vm}}=\text{2}\left(\frac{\mathrm{1,5}\cdot {10}^6(\mathrm{one}+0.2)}{\text{one}\text{,5}+{\text{10}}^{\text{10}}}\right)+{\left[\frac{\mathrm{1,5}\cdot {10}^6(\mathrm{one}+0.2)}{\text{one}\text{,5}\cdot {\text{10}}^{\text{10}}}\right]}^2=\mathrm{0,00024}$$

,

, $${\text{M}}_{\text{on}}=\text{2}\left(\frac{\mathrm{4,5}\cdot {10}^6(\mathrm{one}+0.3)}{\text{four}\cdot {\text{10}}^{\text{10}}}\right)+{\left[\frac{\mathrm{4,5}\cdot {10}^6(\mathrm{one}+0.3)}{\text{four}\cdot {\text{10}}^{\text{10}}}\right]}^2=\mathrm{0,00029}$$

,

$$\begin{array}{l}{d}_{\text{0}}^{\text{on}}=\text{0}25\sqrt{\left(\frac{{\left(\frac{0.1037\cdot 4.21\cdot {10}^9}{1.5\cdot {10}^6}\right)}^{\frac{\mathrm{one}}{1.26}}-\mathrm{one}+\frac{1.5\cdot {10}^6}{0.83\cdot {10}^{10}}}{\left(\frac{0.1037\cdot 4.21\cdot {10}^9}{4.5\cdot {10}^6}\right)-\mathrm{one}+\frac{4.5\cdot {10}^6}{\text{8}\text{, 33}\cdot {\text{10}}^{\text{10}}}}\right)\cdot \left(\frac{\frac{4.5\cdot {10}^6}{8.33\cdot {10}_{10}}+0.00024+0.11}{\frac{1.5\cdot {10}^6}{0.83\cdot {10}^{10}}+0.00029+0.13}\right)}=\\ =0.25\cdot 1.45\approx 0.35\text{m}\text{.}\end{array}$$

Thus, it follows from (1) that, at the intersection intersections of the solid inclusions of the well, the wells should be expanded to a diameter of 350 mm, which allows increasing the SAM to r ₁ . This ensures the complete absence of oversized pieces of rock.

Information sources

1. Bibik I.P., Rakhmanov R.A., Ivanovsky D.S. Improving the efficiency of explosive loosening of multi-strength arrays during the development of the Jeroy-Sardara deposit of phosphorites // Mountain Journal. Non-ferrous metals. Special issue. - 2008. - No. 8. - S. 49-51, Fig. 4, III, b.

2. Drukovany M.F., Dubnov L.V., Kutuzov B.N., Efremov E.I. Handbook of drilling and blasting operations in quarries. - Kiev: Naukova Dumka. - 1973. - P.371, fig. 166, c.

3. Dugartsyrenov A.V. The physical nature and mechanism of rock destruction during a camouflage explosion. Blasting business. Issue No. 106/63. - M .: CJSC “MVK on blasting at AGN”, 2011. - S.112-126.

Claims (1)

A method of blasting diverse rock masses with solid inclusions in open cast mining, including determining the presence of solid inclusions in the enclosing less strong rocks, the plan in plan and the marks of the roof and soil of these inclusions, drilling vertical wells, expanding wells at the intersections of solid inclusions, loading wells with charges of industrial explosives (PVV), the diameter of which is equal to the diameter of the wells, and the blasting of explosive charges, characterized in that the strength limits are preliminarily determined and tensile Poisson's ratio, Young's modulus, porosity, and compression coefficient comprehensive host rocks and solids, while the diameter $$d_0^{\mathrm{at}\mathrm{to}l}$$

expandable sections of wells are taken from the ratio:
$$d_{\text{0}}^{\text{on}}={\text{d}}_{\text{0}}^{\text{vm}}\sqrt{\left(\frac{{\left(\frac{\text{ζ}\cdot {\text{P}}_{\text{0}}}{{\text{σ}}_{\text{races}}^{\text{vm}}}\right)}^{\frac{\text{one}}{{\text{γ}}_{\text{2}}}}-\text{one}+\frac{{\text{σ}}_{\text{races}}^{\text{vm}}}{{\text{K}}_{\text{vm}}}}{{\left(\frac{\text{ζ}\cdot {\text{P}}_{\text{0}}}{{\text{σ}}_{\text{races}}^{\text{on}}}\right)}^{\frac{\text{one}}{{\text{γ}}_{\text{2}}}}-\text{one}+\frac{{\text{σ}}_{\text{races}}^{\text{on}}}{{\text{K}}_{\text{on}}}}\right)\cdot \left(\frac{\frac{{\text{σ}}_{\text{races}}^{\text{on}}}{{\text{K}}_{\text{on}}}+{\text{M}}_{\text{on}}+{\text{P}}_{\text{on}}}{\frac{{\text{σ}}_{\text{races}}^{\text{vm}}}{{\text{K}}_{\text{vm}}}+{\text{M}}_{\text{vm}}+{\text{P}}_{\text{vm}}}\right)},$$

Where $$d_0^{\mathrm{at}m}$$

- diameter of unexpanded sections of wells, mm;
ζ is the adiabatic parameter;
P ₀ - pressure of detonation products at the Jouguet point, Pa;
γ ₂ is an indicator of the isentropic detonation products of PVV;
$${\sigma }_{R\mathrm{but}\mathrm{from}}^{\mathrm{at}\mathrm{to}l}$$

and $${\sigma }_{R\mathrm{but}\mathrm{from}}^{\mathrm{at}m}$$

- accordingly, the strength limits of solid inclusions and host rocks in tension, Pa;
K _on and K _VM - respectively, the coefficients of comprehensive compression of solid inclusions and host rocks;
P _on and P _vm - respectively, the porosity of solid inclusions and host rocks;
$${\text{M}}_{\text{vm}}=\text{2}\left(\frac{{\text{σ}}_{\text{races}}^{\text{vm}}\left(\text{one}+{\text{ν}}^{\text{vm}}\right)}{{\text{E}}^{\text{vm}}}\right)+{\left[\frac{{\text{σ}}_{\text{races}}^{\text{vm}}\left(\text{one}+{\text{ν}}^{\text{vm}}\right)}{{\text{E}}^{\text{vm}}}\right]}^2$$

, a coefficient determining the elastic expansion of the boundary of the camouflage cavity in the host rocks;
$${\text{M}}_{\text{on}}=\text{2}\left(\frac{{\text{σ}}_{\text{races}}^{\text{on}}\left(\text{one}+{\text{ν}}^{\text{on}}\right)}{{\text{E}}^{\text{on}}}\right)+{\left[\frac{{\text{σ}}_{\text{races}}^{\text{on}}\left(\text{one}+{\text{ν}}^{\text{on}}\right)}{{\text{E}}^{\text{on}}}\right]}^2$$

, a coefficient determining the elastic expansion of the boundary of the camouflage cavity in solid inclusions;
ν ^on and ν ^vm are Poisson's ratios of solid inclusions and host rocks, respectively;
E ^on and E ^VM - respectively Young's modulus of solid inclusions and host rocks, Pa.