RU1818519C - Method for blasting watered wells - Google Patents

Abstract

The invention relates to blasting, can be used when loosening 2 rocks in quarries for the extraction of minerals or local building materials and can reduce the cost of drilling and blasting. For this, explosives are chambered into the shell with a diameter not less than the diameter of the borehole; the explosive cartridge is lowered in a length connected to a tight cylindrical cage, determined by the formula I KQ / Ј, 785 (CD - 2D) 2 у, where K is the coefficient reserve; -0 - mass of explosive charge, kg; C is the coefficient of proportionality, less than 1; D is the diameter of the well, m; D is the wall thickness of the cage, m; y - bulk density BBvKr / M3, while holding the cartridge by the downhole at the installation site, the clip is removed from the well. 1 ill. (L

Description

FIELD OF THE INVENTION This invention relates to blasting and can be used for loosening rock in opencast mines for mining or local building materials.

The purpose of the invention is to reduce the cost of drilling and blasting operations.

The essence of the invention lies in the fact that the explosives are chucked into the shell with a diameter not less than the diameter of the borehole, the lowering of the cartridge of the explosive is carried out in a length defined by the formula

I KQ / JO, 785 (CD - 2 D) 2 y,

where K is the reserve ratio;

Q is the mass of the explosive charge, kg;

C is the coefficient of proportionality, less than 1;

D is the diameter of the well, m;

D is the wall thickness of the cage, m;

bulk density В В, kg / m3, while holding the cartridge by the downhole at the installation site, the clip is removed from the well.

The drawing shows a section through the well in the direction of its axis with the explosive cartridge lowered into it.

The method is carried out as follows.

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To charge the borehole 1 drilled in waterlogged rocks, explosives (BB) are chambered into a moisture-proof casing, and the BB 2 cartridge is made of a polyethylene sleeve. Lowering the explosive cartridge into the borehole is carried out in a cylindrical ferrule 3 connected to the rod 4, using the ram 5. The length of the ferrule 3 is determined by the formula

I, 785 (СО-2 / у,

where K is the reserve ratio equal to 1.1-1.2;

Q is the mass of the charge, kg;

C is a proportionality coefficient, providing for the conditions of free lowering of the cartridge 2 in the holder 3 along the well 1. The coefficient value is taken equal to 0.8-0.9;

D is the diameter of the well, m;

L-wall thickness of the cage, m;

bulk density B, kg / m3.

The outer diameter of the sleeve 3 corresponds to the value of CD. The length of the cartridge 3 corresponds to the length of the cartridge B B 2. Observance of the indicated values ensures that the cartridge 2 is placed inside the cartridge 3. In the manufacture of the cartridge 2, the sleeve serving as the shell of the cartridge 2 is crimped to eliminate the formation of an air bubble inside the cartridge 2.

After lowering the cartridge 2 at the same time while holding it at the installation site by the downhole 5, the clip 3 for pull 4 is removed from the well 1.

The cartridge 2, freed from the cage 3, under the force transmitted by the face 5, is shortened in length and increases in diameter, filling the cross section of the well 1. After this, the cartridge BB 2 is blown up.

An example of the proposed method is given below.

A borehole with a diameter of 220 m drilled in flooded rock formations is charged with a non-resistant 79/21 grammonite. Pre-grammonite is patronized in waterproof polyethylene shells. For the manufacture of grammonite cartridges weighing 15 kg each, a polyethylene sleeve with a diameter of 0.225 m is used. To lower the cartridge into the well, a cylindrical ferrule with an outer diameter of 0.9 x 0.225 0.2 m and a wall thickness of 0.005 m is used.

The length of the cartridge is taken equal to the length of the cage and is calculated by the formula

I 2: KQ / 0.785 (CD - 2D) 2 yh - 1.2 x .785 (0.9 x 0.225 - - 2 x 0.005) 2 x 900h 0.7 m.

The cartridge is adopted at the same length so that the cartridge can be fully stacked within the cartridge. In the manufacture of a cartridge, after filling grammonite into a polyethylene sleeve, the latter is crimped to eliminate the air bubble and clogged. Before lowering into the well, the cartridge is laid in

a clip connected to a rope used as a pull during charging. The cartridge in the cage is inserted into the well and sent to the bottom by the face of the hole.

At the installation site, the cartridge is held by the downhole, and the clip is removed from the well. During the release from the cage, the cartridge completely fills the well section and shortens in length.

The invention provides an increase in the linear charge density and an increase in the grid location of the wells, which determines a reduction in the volume of drilling operations; increased productivity and reduced lead time.

Claims (1)

The claims A method for blasting waterlogged wells, including patronizing a non-water-resistant explosive in a moisture-proof casing, lowering an explosive cartridge with a bottomhole into a well and blasting a cartridge, characterized in that, in order to reduce the cost of drilling and blasting operations, explosives are chucked into shells with a diameter not smaller than the diameter of the well, the lowering of the cartridge is carried out in a length I connected to a cylindrical cage, determined from the expression fifty I, 785 (), where K is the reserve ratio equal to 1.1-1.2: Q is the mass of the explosive charge, kg; C is the coefficient of proportionality, less than 1; D is the diameter of the well, m; D-wall thickness of the cage, m; the bulk density of the explosive is at the same time the cartridge is held in place by the downhole. kg / me.ste installation, and the clip is removed from the well.