RU2305823C1 - Method for loading inclined wells - Google Patents

Abstract

FIELD: mining industry, possible use during open extraction of mineral resources for processing shelves in open-cut mines and hydro-engineering.

SUBSTANCE: method for loading inclined wells with a charge having diameter lesser than that of drilled well, includes drilling of well, lowering a waterproof case made of elastic material down into the well to its face and following feeding of emulsion explosive substance into the case. Waterproof cover is made corrugated and its open end is held on loading hose of loading machine. Lowering of waterproof cover into the well is performed for whole depth together with loading hose for whole depth, the latter being extracted afterwards with a speed which matches the speed of filling of waterproof case with emulsion explosive substance. Diameter of charge placed in the waterproof case exceeds, at least twice, the critical detonation diameter d^H _cr, of emulsion explosive substance, positioned in a layer on well face, while critical detonation diameter of emulsion explosive substance in a layer, located in well face, is determined according to formula: d^H _cr=5,18+exp[-46,051+52,235ρ^H _rel], mm, where d^H _cr - critical detonation diameter of an emulsion explosive substance layer, located at depth H of the well; ρ^H _rel - relative density of emulsion explosive substance layer at depth of H meters.

EFFECT: increased productivity of drilling and explosive operations in open-cut mine.

2 cl, 1 tbl

Description

The invention relates to the mining industry and can be used in open pit mining for ejection of ledges in quarries and in hydraulic engineering.

A known method of loading flooded downhole wells with water-based explosive substances (WWE), according to which a waterproof flexible sleeve with a damped lower end is placed in the well. After placement in the well, the sleeve is fixed in the near-well part of the well to its walls along the entire perimeter and to a height of 1.5 diameters of the well by bursting forces acting from the internal cavity of the sleeve. A mixture of components with a chemically active gas-generating additive introduced into it during the charging process is used as the BCB. When fed into the sleeve, this mixture has a density higher than the density of the borehole water, and the density of the finished water-borne water after the chemical reaction of the gas-generating additive with at least one of the components of the water-borne water is lower than the density of the borehole water (see RF patent No. 2088893, M. class F42D 1/00, 1997).

The disadvantage of this method is the insufficient level of reliability of charge formation.

There is a method of forming a hose contour charges from water-containing explosives, which consists in drilling a well with a diameter greater than the charge diameter, lowering a waterproof shell made of elastic material into the well before slaughtering it and then supplying a mixed explosive shell inside (see RF patent No. 2097680, M. cl F42D 3/04, 1997).

The disadvantage of this method is the possibility of twisting the waterproof shell when lowering it into the well, as well as the possibility of crushing it under the influence of water pressure, which may be in the well, which negatively affects the reliability of the formation of the charge of the emulsion explosives.

The invention solves the problem of increasing the reliability of the formation of the charge of the emulsion explosive placed in a flexible waterproof shell.

The technical result that can be obtained by carrying out the invention is to increase the level of industrial safety and productivity during drilling and blasting operations in the quarry.

The specified technical result is achieved by the fact that in the proposed method of loading deviated wells with a charge with a diameter smaller than the diameter of the drilled well, including drilling the well, lowering into the well until it is slammed shut from one end of a waterproof shell of elastic material and subsequent supply of an emulsion explosive shell inside, the waterproof shell is corrugated and its non-plugged end is fixed to the charging hose of the charging machine, the waterproof shell being assembled into the well in the assembled m to produce a full depth together with the charging hose, which is then removed from the well at a rate compatible with the rate of filling waterproof shell emulsion explosives.

In addition, because the diameter of the charge placed in the waterproof shell exceeds at least two times the critical diameter of the detonation of the emulsion explosives located in the layer at a depth H of the well, while the critical diameter of the detonation of the emulsion explosives located in the layer at a depth of H, d ⁿ _cr wells are determined by the experimentally obtained dependence:

d ⁿ _cr = 5.18 + exp [-46.051 + 52.235ρ ⁿ _rel ], mm,

where d ⁿ _cr - the critical diameter of the detonation of emulsion explosives in the layer located at the bottom of the well;

ρ ⁿ _rel - the relative density of the emulsion explosive layer at a depth of H meters.

The indicated combination includes features, each of which is necessary, and all together are sufficient to achieve the claimed technical result in all cases of using the invention, to which the requested amount of legal protection applies.

The method is as follows. Drilling a ledge quarry produce wells of the same diameter. The boreholes are charged to full depth with an emulsion explosive using a mixed charging machine (SPM). Contour boreholes are drilled at an angle to the horizon, for example, parallel to the ledge board. To load the contour wells, reduced weight charges are used, which allows to increase the stability of the sides of the ledges, put in the final position, due to the reduction of the explosion energy transfer to the array. In the proposed method of loading when using emulsion explosives and SPM, a decrease in the weight of the charge is achieved by reducing the diameter of the charge.

In this case, the charge formation is carried out using a waterproof sheath made of an elastic material, for example, a fabric sleeve or a sleeve of a seamless multilayer polymer film such as polyamide-polyethylene film. The specified sleeve in the form of a corrugated shell having an expanded length of not less than the depth of the charged well is put on the SZM charging hose and the upper end of the shell is fixed on the hose. The lower end of the shell is plugged and in this form, the charging hose is fed to the bottom of the well to its entire depth. Since the corrugated shell attached to the SZM charging hose significantly increases the outer diameter of the charging hose, a necessary condition for unhindered descent of the hose to the bottom of the well is to exceed the diameter of the drilled well in relation to the diameter of the charge by at least two times.

After the end of the charging hose reaches the bottom of the well, an emulsion explosive is fed into the shell, which expands when filled. Simultaneously with the filling of the shell, the hose is lifted by winding it onto the SPM drum. In this case, it is preferable to maintain the lifting speed consistent with the filling speed of the shell. This ensures uniform filling of the shell with an emulsion explosive, the absence of pinch and bend of the shell in the well. After filling the shell with emulsion explosive in the required amount and lifting the charging hose from the well, the fixed end of the shell is removed from the hose and drowned.

The described method of loading allows you to mechanize the process of loading wells of one diameter with charges of emulsion explosives of different weights using the same equipment.

To exclude failures during explosions of charges of reduced diameter, as well as to ensure maximum energy release during explosion of a charge, it is necessary to observe the condition:

d _zar > 2d _cr

where: d _zar - the diameter of the charge emulsion explosives,

d _cr - the critical diameter of the detonation of emulsion explosives.

Emulsion explosive consists of ammonium or sodium nitrate, water, oil, emulsifier, processing aids and a sensitizer (gas generating additive) and is an inverse emulsion of a highly concentrated solution of an oxidizing agent in an oil product. The permissible density of the emulsion explosive, at which stationary detonation of the hose charge of a specific diameter is provided, depends on the depth of the well, the angle of its inclination and the relative density (porosity) of the emulsion explosive.

The critical detonation diameter depends on the relative density of the emulsion explosive (ρ _rel ), which in turn depends on hydrostatic pressure, i.e. from the distance (N) from the bottom of the well to the surface.

In view of the foregoing, it is necessary to verify the possibility of using a specific emulsion explosive charge in specific wells.

To this end, initially determine the maximum possible density of explosives of a particular chemical composition, i.e. specific gravity (ρ _max ). Then, the initial density of the emulsion explosive is set, i.e. density of emulsion explosives at atmospheric pressure (ρ ⁰ ). After that, the initial relative density of the emulsion explosive is calculated

(ρ ⁰ _rel = ρ ⁰ / ρ _max )

Taking into account the angle of inclination of the well, the value of the relative density of the emulsion explosive is calculated at a depth of N, m (ρ ⁿ _rel ):

ρ ⁿ _rel = ρ ⁰ _rel H ^{0.25642 (1-ρ rel)}

Using the obtained value ρ ⁿ _rel , calculate the value of the critical diameter of the detonation d ⁿ _cr , mm, emulsion explosives located on the bottom of the well, according to the experimentally established formula:

Based on the obtained value of d ⁿ _cr choose the diameter of the hose charge, which must comply with the above conditions. If there is a need to change the diameter of the charge, the calculation is repeated for another value ρ ⁰ .

If the well is flooded and its angle of inclination exceeds 45 °, it is necessary that the average charge density exceed the density of water to prevent the emergence of a charge.

Example.

Emulsion explosive is a water-in-oil inverse emulsion sensitized by gas bubbles in the following ratio of ingredients, wt.%:

ammonium nitrate - 79 water - fifteen mineral oil - 5.3 emulsifier - 0.7

The maximum density of such an emulsion explosive ρ _max = 1.35 _{g / cm} ³

Hose charge conditions:

- well diameter 215 mm;

- well length 28 m;

- well inclination angle 45 °;

- well depth H = 28 Sin 45 ° = 20 m

Using the above data, we will calculate by the formula (1) for several values of the initial density ρ ⁰ , we will reduce the data to table No. 1

Options Values ρ _max , g / cm ³ 1.35 N, m twenty ρ ⁰ , g / cm ³ 1.10 1.15 1.20 ρ ⁰ _rel , g / cm ³ 0.815 0.852 0.889 ρ ²⁰ _rel , g / cm ³ , 0.940 0.954 0.972 d ²⁰ _cr , mm 26 49 117 _hose d fifty one hundred 250

As follows from the calculation, for the unhindered introduction of the corrugated shell of the hose charge into the borehole with a diameter of 215 mm and its effective detonation, the initial density ρ ⁰ should not exceed 1.15 g / cm ³ . In this case, the outer diameter of the hose should not be less than 100 mm, taking into account the required level of energy content, and the diameter of the hose charge should not be more than 0.5 from the diameter of the well - 107 mm.

Claims (2)

1. The method of loading deviated wells with a charge with a diameter smaller than the diameter of the drilled well, including drilling the well, descending into the well before it is slammed shut from one end of a waterproof shell of elastic material and then supplying an emulsion explosive shell inside, characterized in that the waterproof shell is the corrugated and its non-plugged end is fixed on the charging hose of the charging machine, and the waterproof shell is assembled into the well in the assembled form to the entire depth together with a charging hose, which is then removed from the well at a speed consistent with the rate of filling of the waterproof shell with an emulsion explosive. 2. The method according to claim 1, characterized in that the diameter of the charge placed in a waterproof shell exceeds at least two times the critical diameter of detonation, d ⁿ _cr , emulsion explosives located in the layer at the bottom of the well, while the critical diameter of detonation Emulsion explosives in the layer located at the bottom of the well is determined by the formula d ⁿ _cr = 5.18 + exp [-46.051 + 52.235ρ ⁿ _rel ], mm, where d ⁿ _cr - the critical diameter of the detonation of the emulsion explosive layer located at a depth of N wells; ρ ⁿ _rel - the relative density of the emulsion explosive layer at a depth of H meters.