RU1774156C - Method of breaking down rocks - Google Patents

Abstract

The invention relates to mining and can be used in the construction of underground workings using a blasting method. The purpose of the invention is to increase efficiency by reducing the contour disturbance of the massif. The method of subsequent contouring blasting during underground mining 1 involves drilling holes along the contour of the mine, charging them with explosive charges and blasting explosive charges sequentially one after another. In the method, the distance between the contour holes is determined from the ratio a m, a (50 P-Q-A-d32) / dw2 (MO7 + kpgh) where P is the mass of the explosive charge in a meter of the hole, kg / m; Q — specific heat of explosion, kcal / kg, A — mechanical heat equivalent, 4.1810 J / cal; f is the coefficient of rock (ore) strength according to the MM scale Protode conova p - averaged density of overlying rocks kg / m; g is the acceleration of gravity, m / s: h is the depth of blasting from the surface, m; K is the concentration coefficient of excess energy; d3 is the diameter of the explosive charge, m; dm - borehole diameter, m. SG С

Description

The invention relates to mining and can be used in the construction of underground workings using a blasting method.

There is a known method for subsequent contouring blasting during underground workings, including drilling holes along the working contour, charging them with explosive charges and blasting explosive charges sequentially one after another 1.

The disadvantage of this method is that it does not take into account the strength of the rocks (ores), the energy of the explosion (type of explosives), the depth of the work from the surface, the effect of the crescent air gap between the cartridges

Explosives and borehole walls (with trained loading) - this leads to the fact that the specific consumption of explosives in various mining conditions is constant, i.e. in some cases there will be a shortage of rock, and in other cases excessive contour crushing of the massif, which does not allow to obtain a high-quality output contour.

The closest method is the method of subsequent contouring blasting during underground workings, including drilling holes along the working loop, charging them with explosive charges and blasting explosive charges sequentially one after another 2.

but a

A disadvantage of the known method is that it ignores rock pressure and redistribution of rock pressure near the underground mine, and also does not take into account the explosion energy of the explosive, which does not allow to obtain a high-quality mine circuit, leads to contour crushing of the massif and subsequent conclusions. All this reduces the effectiveness of the method.

The purpose of the invention is to increase efficiency by reducing marginal disturbance of the rock mass.

The essence of the method lies in the fact that in the method of breaking rocks, including drilling of jack and contouring holes, loading them with explosive charges and sequential blasting, first charges in jack and then contouring holes, contouring holes at a distance from each other, which is determined from the expression

50P-0-A-SJ

ai (M07 + K- / o-h-g)

where P is the mass of the explosive charge in a meter of borehole, kg / m; Q - specific heat of explosion, kcal / kg; A - mechanical equivalent of heat - 4.18 x KU4, J / kcal; f is the rock strength coefficient on the M. M. Prod scale; p - averaged density of overlying rocks, kg / m3; g is the acceleration of gravity, m / s2; h is the depth of blasting from the surface, m; K is the concentration coefficient of excess voltages (can be assumed to be 2.75 according to P.M. Tsymbarevich); d3 is the diameter of the explosive charge, m; - borehole diameter, m; a - distance between the axes of the contour holes, m.

Example. We determine the parameters of explosive blasting if work is carried out at a depth of h 330 m; B - detonite - 10 A; P 0.54 kg / m; Q 1200 kcal / kg; d3 0.024 m; Yesh 0.036 m; K 2.75; p-2600 kg / m3; g 9.81 m / s2,.

0

5

0

5

0

5

, 54X1200 4,, 0242 „s

and ts 0, ohm

0.0362 (108 + 2 ,,)

The distance from the line of contouring holes to the exposed surface (line of least resistance) is determined by the well-known formula

W 1.11a,

where W is the line of least resistance, m.

Lines of least resistance

W 1.11 a 0.55 m.

Claims (1)

The claims A method of breaking rocks, including drilling of jack and contouring holes, charging them with explosives (HE) and sequentially blasting charges first in jack and then contouring holes, characterized in that, in order to increase efficiency by reducing the edge disturbances of the mountain range, the contouring bore holes are drilled at a distance from each other, which is determined from the expression 50P-0-A-sho diL (M07 + K-p g h) where P is the mass of the explosive charge in a meter of borehole, kg / m; Q is the specific heat of the explosion, kcal / kg, A is the mechanical equivalent of heat. 4, J / kcal; f is the coefficient of rock (ore) strength according to the MM Protodon Konov scale; p - averaged density of overlying rocks, kg / m; a is the acceleration of gravity, m / s, and h is the depth of blasting from the surface, m; K is the concentration coefficient of excess energy; d3 is the diameter of the explosive charge, m, duu - borehole diameter, m.