RU2080315C1 - Method of manufacturing borehole charge - Google Patents

Abstract

FIELD: borehole drilling. SUBSTANCE: method consists in using as explosive bundles of tubular mono- or dibasic powder which are dipped into borehole and free space between bundles and borehole walls is filled with loose industrial explosive or saturated ammonium nitrate aqueous solution. Method ensures increase in borehole charge density to 0.75-0.95 g/cu.cm and safe operation, as well as reduction in cost of drill-and-fire works by 1.3-2.5 times. EFFECT: enhanced efficiency and reduced cost. 3 cl, 3 dwg

Description

 The invention relates to the field of blasting on the earth's surface, in particular to a method for producing a borehole charge when using single and dibasic gunpowders in the form of a tube as industrial explosives (industrial explosives).

The use of mono- and dibasic powders as an industrial. BB is known [RF patents NN 2026274, 2026275, 2026272 and other US patent N 3235425, UK patent N 1216299]
Created on the basis of one and dibasic gunpowder prom. BB belong to the class of granular patents of the Russian Federation NN 2026274, 2026275, or water-containing (suspension and emulsion) RF patent N 2026272, US patent N 3235425, UK patent N 1216229.

It is known that a borehole charge is made by loading a granular industrial. Explosives into the well manually or using special machines with a charge density of 0.75 to 0.95 g / cm ³ [Cook MA The science of industrial explosives. M. Nedra, 1980; Dubnov L.V. Bakharevich N.S. Romanov A.I. Industrial explosives.-M. Nedra, 1988]
In all these cases, the powder is subjected to grinding or cutting into elements of a given shape and size.

 The powder grinding phase is labor-intensive and energy-intensive, explosive and requires the development and installation of new additional equipment. Particularly time-consuming is the process of grinding monobasic (pyroxylin) powders, which are inherently thermosets. The organization of powder grinding sites at blasting sites is not economically feasible.

 Therefore, the main disadvantage of the manufacture of borehole charges from granular, suspension and emulsion industrial. Explosives based on gunpowder is the high cost of blasting.

The use of a tube of one and dibasic gunpowders without preliminary grinding for the manufacture of borehole charges is difficult for the following reasons:
1. The loading density of the well when loading single tubes does not exceed 0.4 0.5 g / cm ³ due to their random location in the well, the continuity and continuity of the column of the borehole charge are not ensured.

2. A bundle of connected tubes has a so-called bulk density of 0.8 0.85 g / cm ³ with a powder density of 1.54 1.65 g / cm ³ .

To ensure the safety of loading wells with tube bundles, the ratio d ₃ / D _well between the diameter of the tube bundle (d _s ) and the diameter of the well (D _well ) should be at least 0.9, which leads to a decrease in the density of loading wells.

 3. When lowering (dumping) the tube bundle into the well, the latter should completely overlap each other's cross-section for reliable transmission of detonation from one bundle to another. In the absence of 100% overlap, the parallelism of the arrangement of the beams relative to the walls of the well, the detonation pulse (shock wave) from the initiator (checkers-detonator) and from the beam to the beam weakens and can completely decay, which leads to failure in the operation of well charges.

 An object of the invention was the creation of a method of manufacturing a borehole charge from tubular powders without prior grinding, eliminating the above disadvantages.

 The problem is solved due to the fact that the beam is preliminarily formed from a tube of monobasic or dibasic gunpowder, the bundles are loaded into the well, and the free space between the bundles and the walls of the well is filled with loose (granular) industrial explosives, or granular ammonium nitrate, or a saturated aqueous solution of ammonium nitrate.

 Preferably, the bundles are formed (“knitted”) from tubes of the same length. The outer and inner diameters of the tube may be different. In addition, you can use ready-made previously manufactured bundles of tubes in storage warehouses.

 To ensure the safety of loading wells, the diameter of the tube bundle should be no more than 0.9, and from the point of profitability and the feasibility of using tubular powders at least 0.5 of the diameter of the well.

The proposed method provides an increase in the density of loading wells to 0.75 0.95 g / cm ³ , a decrease in the cost of drilling and blasting 1.3 to 2.5 times.

 In FIG. 1 shows a borehole charge, a general view; in FIG. 2 the dependence of the linear and volumetric density of the well loading by bundles of tubes on the relationship between the diameter of the beam and the diameter of the well; in FIG. 3 dependence of the detonation velocity and detonation pressure on the charge density.

 In FIG. 1 shows a view of a downhole charge consisting of bundles of tubes and a bulk industrial. BB

In FIG. 2 shows a linear dependence (curves 1 and 3) and volume (curves 2 and 4) loading densities on the ratio d ₃ / D _borehole between the beam diameter (d ₃₎ and hole diameter (D _BH). Curves 1 and 2 relate to powder beams with a density of 0.8 g / cm ³ , curves 3 and 4 0.9 g / cm ³ .

The density of the powder is 1.54 g / cm ³ .

As follows from FIG. 2, the linear and volumetric loading densities increase with increasing ratio d ₃ / D _well and reach their maximum when the beam and well diameters are equal.

 In FIG. Figure 3 shows the dependences of the detonation velocity (D) curve 1 and the detonation pressure of the explosion products (P) curve 2 on the charge density (ρ). The higher the charge density, the higher the speed and pressure of detonation.

It is known that the sensitivity of gunpowder to a shock wave is estimated by the critical pressure of detonation excitation and for mono- and dibasic gunpowders it is 4.5 6.0 GPA. As follows from the data of FIG. 3, failure-free operation of the borehole charge can be achieved with a loading density of at least 0.75 g / cm ³ , which can only be achieved by filling the free space between the powder beams and the walls of the well with a loose prom. BB

 A method of manufacturing a borehole charge (a method of loading wells) is as follows: a bundle of powder tubes of the same length is formed, which are connected on both sides at a distance of 60 ± 10 mm, for example, with a linen cord or twine so that the tubes do not fall out of the beam. In one bundle, tubes with different outer and inner diameters can be used. Knitting of beams can be carried out in the factory, in warehouses for storing a powder tube or at stationary points of blasting sites. Beams of any length are suitable for loading wells. The fabricated beams are loaded into the well and periodically fill the free space in the well with granular ammonium nitrate, bulk industrial explosives, or filled with a saturated aqueous solution of ammonium nitrate. When charging flooded wells with running water, a thickener, for example, sodium carboxymethyl cellulose or polyacrylamide, is introduced into a saturated solution of ammonium nitrate.

 Well plugging and initiation of borehole charges are carried out by the method adopted at this quarry.

Example 1
Diameter of wells, mm 152
Depth of wells, m 3
Stacking of wells, m 1,5
Drilling grid, m 4x5
Well loading (capacity), kg 25
of which powder bunches with a diameter of 120 mm, kg 18
Ammonium nitrate GOST 2-85, kg 7
The ratio of d ₃ / D _SLE 0.8
The ratio of gunpowder: saltpeter 2.6: 1
Loading density, g / cm ³ 0.92
Example 2
Diameter of wells, mm 216
Depth of wells, m 13
Zaboyka, m 2
Drilling grid, m 4x4.6
Well loading, kg 341
of which powder bunches with a diameter of 175 mm, kg 211
Grammonite GOST 21988-76, kg 130
The ratio of d ₃ / D _SLE 0.7
The ratio of gunpowder: grammonite 1.6: 1
Loading density, g / cm ³ 0,85
Example 3
Diameter of wells, mm 216
Depth of wells, m 13
Zaboyka, m 2
Drilling grid, m 4x4.6
Well loading, kg 326
of which powder bunches with a diameter of 200 mm, kg 276
Granulotol OST 84-882-74, kg 50
The ratio of d ₃ / D _SLE 0.8
The ratio of gunpowder: granulotol 5.5: 1
Loading density, g / cm ³ 0,8
Downhole charges were manufactured analogously to example 3, where the TU 84-7509009.06-90 granipore was used as a bulk industrial explosive; granipor TU 84-7509009.31-92; granulite OCT 21 987-76; grammonal
Example 4
Diameter of wells, mm 216
Depth of wells, m 13
Stacking of wells, m 2
Drilling grid, m 4x4.6
Well loading, kg 306
of which powder bunches with a diameter of 120 mm, kg 200
Alumotol GOST 12696-67, kg 106
The ratio of d ₃ / D _SLE 0.56
The ratio of gunpowder: alumotol 1.9: 1
Loading density, g / cm ³ 0.76
Example 5
Diameter of wells, mm 216
Depth of wells, m 13
Stacking of wells, m 2
Drilling grid, m 6x6
Well loading, kg 441
of which powder bunches with a diameter of 200 mm, kg 276
Saturated solution of ammonium nitrate, kg 165
The ratio of d ₃ / D _SLE 0.8
The ratio of gunpowder: a solution of saltpeter 1.7: 1
Loading density, g / cm ³ 1,1
Example 6
Diameter of wells, mm 152
Depth of wells, m 3
Stacking of wells, m 1,5
Well loading, kg 30
of which powder bunches with a diameter of 130 mm, kg 18
Saturated solution of ammonium nitrate, thickened with sodium salt of carboxymethyl cellulose, kg 12
The ratio of d ₃ / D _SLE 0.85
The ratio of gunpowder: a solution of nitrate of 1.5: 1
Loading density, g / cm ³ 1,1
During explosions, militants (detonator drafts) are installed in the upper and lower parts of the well for all examples.

Explosion rates (for all examples)
Specific consumption of explosives, kg / m ^{3 of} blasted rock 0.52-0.76
Camber width, m 40-45
Cast for the last row of wells
Rock crushing Within normal limits
Visible thresholds or failures Not recorded.

 According to statistics, the cost of prom. Explosive is 30-60% of the cost of drilling and blasting. The proposed method for manufacturing a borehole charge using a beam of powder tubes (without preliminary grinding) reduces the cost of drilling and blasting by 1.3-2.5 times, because the cost of knitting beams is 8-10 times lower than the cost of grinding a powder tube.

Claims (3)

 1. A method of manufacturing a borehole charge, comprising loading the borehole with explosive, characterized in that formed bunches of tubular monobasic or dibasic gunpowder are used as the explosive, the bunches are loaded into the borehole, and the free space between the bunches and the walls is filled with loose industrial explosives or saturated aqueous ammonium nitrate solution.  2. The method according to p. 1, characterized in that the granular industrial explosives use granulotol, or grammonite, or granulite, or gramonal, or alumotol, or granipor, or granular ammonium nitrate.  3. The method according to p. 1, characterized in that the saturated aqueous solution of ammonium nitrate is thickened before feeding into the well, for example with sodium salt of carboxymethyl cellulose or polyacrylamide.

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