RU2632987C1 - Method for forming charge of blasting explosive in well - Google Patents

Abstract

FIELD: blasting.

SUBSTANCE: hole charging is performed with the dispersal of charges to the main and intermediate charges. In this case, the main charge is placed on the bottom of the well in four arms arranged mutually perpendicular to each other. Between the horizontal charges, air gaps are formed, and a locking plug is installed at the wellhead. An additional charge of blasting explosive is placed in the borehole at a distance equal to half height of the ledge, and the remaining space of the well is covered with basting material. The invention makes it possible to increase the efficiency of drilling-and-blasting breakage. A significant reduction in the specific consumption of the explosive on 1m³ of rocks, rock output from 1 p.m of the well, drilling volumes.

EFFECT: quality of toe reaming improved.

1 tbl, 3 dwg

Description

The invention relates to the mining industry and can be used in explosive borehole rock breaking in opencast mining.

There are various methods of blasting, for example, when creating open profile workings in soils by increasing the speed of the shock wave in the bottom parts of the charging cavities (see SU No. 1538659, class F42D7 / 00, publ. 1988), by carrying out a borehole explosion by saving the stability of the explosive composition with a high temperature gradient of air and interfering rocks (see SU No. 1295820, class E21С37 / 00, F42D3 / 04, publ. 1985), by the method of intensifying the uneven effect of the explosion along the length of the well (see SU No. 1540431, class. F42D3 / 00, publ. 1988), the formation of borehole row (see SU No. 1582791) by placing additional dispersed charges in the well in the form of cylindrical segments with filling gaps with casing material, etc.

Common disadvantages of the known solutions are the lack of directional action of the shock wave in the mass of the blasting block, the complexity of the design of the explosive charge and their execution, the inability to control the accuracy of the formation of the cumulative funnel during the loading of the wells, the low quality of working out the bottom of the ledge, etc.

A known method of charge dispersal in a well (see RU No. 2437056, class F42D1 / 08, published December 20, 2011), including suspension at a given depth of the well shutter and its subsequent jamming. At the same time, a hollow biconical container made of plastic mass is suspended as a borehole shutter, and it is wedged by adding several portions of crushed stone of a fraction of 10-20 mm into the well with it.

A disadvantage of the known technical solution is the possible low quality of working out the sole of the ledge, since the dispersal of charges occurs only in a vertical cavity.

The method of forming air gaps in a well with an expanded charging cavity (see RU No. 2317517, class F42D1 / 08, publ. 02.20.2008) involves drilling a blast hole of small diameter with subsequent expansion of several boiler cavities located one above the other at a given height a given diameter and the separation of the explosive charge into parts by the air gap. The distance between the boiler cavities along the height of the well is taken equal to the height of the air gaps, and the air gaps form between the boiler cavities in the small-diameter well using a device containing an elastic shutter blocking the well section, made in the form of an opening umbrella with stiffeners made of elastic strings in the form of diverging rays bonded with umbrella material. The stiffeners are made of variable stiffness, decreasing in magnitude from the center to their ends, and connected to a truncated cone directed by a large base to the air gap.

With all the advantages, the well-known technical solution is characterized by the complexity of the design of the borehole charge, the complexity of its execution and the low quality of working out the bottom of the ledge, which together reduce the efficiency of blasting the borehole charge.

The task to which the claimed invention is directed is to increase the efficiency of drilling and blasting blasting by improving the design of the borehole charge.

This goal is achieved by the fact that in the method of generating an explosive charge in the well, the main charge is placed at the bottom of the well in arms oriented along the bottom of the step perpendicular to each other in four directions, creating an air gap between these charges in a horizontal cavity, the upper wellhead of the well is locked plug, and an additional explosive charge in the wellbore is placed at a distance equal to half the height of the ledge with filling the remaining space of the well m pictures.

A comparative analysis of the characteristics of the claimed solution with the signs of analogues indicates the conformity of the claimed solution to the criterion of "novelty."

In the proposed method, new features in comparison with analogues are:

- creation of a new well design with horizontal mutually perpendicularly located cavities at the bottom of the well;

- a new principle for the formation of the air gap in the horizontal cavity of the well;

- orientation of the cavities according to the level of the bottom of the ledge and neighboring wells;

- the location of the additional explosive charge in the wellbore in the gap between the bottomhole material and the locking plug.

These new features eliminate the disadvantages of existing methods of forming an explosive charge and provide the following enhanced positive properties:

- the formation of cavities with an air gap and horizontally creates the conditions for a better study of the sole of the ledge during explosive blasting;

- the dispersion of charges in the vertical and horizontal cavities allows you to evenly distribute the energy of the explosive in the detonated block;

- the placement of the locking plug at the wellhead ensures the formation of an air gap at the bottom of the well.

The whole complex of the listed features, in general, guarantees the creation of a new method for generating explosive charge in the well.

The method is illustrated by drawings, where in FIG. 1 is a cross-sectional diagram of a borehole charge; FIG. 2 is a diagram of the location of the wells in terms of the blasting block and their main parameters, FIG. 3 - design diagram of the borehole charge.

The method is as follows.

A downhole charge is formed with the placement of explosive 1 (see Fig. 1) at the level of the bottom of the ledge in four arms with air gaps 2. After charging the main charges 1, a locking plug 3 is installed at the bottom of each well to place the casing material 4 and an intermediate charge 5. The initiation of charges 1 and 5 is carried out using the detonating cord 6 and the capsule of the detonator 7 (see Fig. 2).

The intermediate charge 5 is placed at a depth equal to half the height of the ledge H _y , which allows to achieve uniform crushing of rocks of the blasting massif 8.

The location of charges 1 in the sleeves with air gaps 2 provides a better study of the sole of the ledge, preventing the process of propagation of detonation products along the axis of the well.

As a result of the implementation of this method of charge formation in the well, the specific consumption of explosive per 1 m ³ of rocks will be significantly reduced, the yield of rocks from 1 lm wells, the volume of drilling operations due to the expansion of the grid of wells and the reduction of their size of the bores, and the quality of working out the bottom of the ledge will improve.

An example of a specific implementation of the method.

The technical essence and advantages of the new technical solution are disclosed by the example of explosive blasting of the block by the recommended method with the following parameters (see Fig. 3) of the initial data for calculations:

- the height of the ledge, N _y = 15 m;

- the slope angle of the ledge, α = 75 °;

- brand of drilling rig, SBSh - 320;

- well diameter, d _c = 320 mm;

- rock strength (sandstones), f = 9;

- bore hole with traditional technology, L _p = 20%;

- the length of the blasting block, L _B = 100 m;

- block width, W = 40 m;

- grid of wells, 7 × 7 m;

- specific consumption of explosives, q = 0.5 kg / m ³ ;

- the cost of an explosive, 600 dollars per ton.

In FIG. 3 shows the calculated (formalized) layout of wells in the blasting unit as one of the options for the execution of technical solutions. The calculations are performed in the following sequence:

I. Traditional technology

1. The depth of the well with traditional technology L ^T _c equal

= H_у + Н_y ⋅ L_пер;

= H_at+ H_y⋅ L_per;

L _per = 0.2 ⋅ N _y

where L _per - the length of the borehole well, comprising 20% of the height of the ledge, m

= 15 + 15 ⋅ 0,2 = 18 м.

= 15 + 15 ⋅ 0.2 = 18 m.

2. The volume of the blasted block - V _B ,

V _B = N _y ⋅ L _B ⋅ W = 15 ⋅ 100 ⋅ 40 = 60,000 m ³ .

,3. The volume of drilling in the blasting unit - ∑

,

= n_c ⋅

,∑

 = n_c ⋅

,

– количество скважин во взрываемом блоке, шт.Where

- the number of wells in the blasting unit, pcs.

where 7 × 7 - grid wells, m,

= 84 ⋅ 18 = 1512 м.where, ∑

= 84 ⋅ 18 = 1512 m.

,4. The output of the rock with 1 pm well -

,

=

=

= 40 м³.

=

=

= 40 m ³ .

,5. Drilling costs -

,

₌ С_пм ⋅ ∑

,

₌FROM_pm⋅ ∑

,

where C _pm - the cost of drilling 1p.m well, dollars / m.

The drilling cost of 1 lm was taken from the actual performance indicators of the enterprises of AK Alrosa (OJSC) and amounted to C _pm = 0.34 dollars / lm, i.e. 10% of the total cost of developing 1 m ^{3 of} overburden (see description RU No. 2233982, class E21C41 / 00, publ. 10.08.2004), then:

= 0,34 ⋅ 1512 = 514,1 долл.

= 0.34 ⋅ 1512 = $ 514.1

,6. The cost of blasting will be -

,

₌ q ⋅ V_Б ⋅ С_ВВ,

₌q ⋅ V_B⋅ C_BB

where C _BB - the cost of explosives, dollars / kg,

C _BB = 0.6 dollars / kg;

₌ 0,5 ⋅ 60000 ⋅ 0,6 = 18000 долл.

₌0.5 ⋅ 60,000 ⋅ 0.6 = $ 18,000

Total cost with traditional technology - З ^T ,

+

= 514,1 + 18000 = 18514,1 долл.3^T =

+

= 514.1 + 18000 = $ 18514.1

II. Recommended Technology

(см. фиг. 3),1. Well depth with the recommended technology -

(see Fig. 3),

= H₁ +

,

= H ₁ +

,

where H ₁ - the length of the vertical section of the well, m;

H ₂ - the length of the inclined section of the well, m;

– угол наклона скважины, град

= 50^°;

- well angle, deg

= 50 ^° ;

Н_у ; H₂ =

H_у;H ₁ =

N _y ; H ₂ =

H _y ;

⋅ 15м = 10 м; Н₂ =

Н_у = 5 м,H ₁ =

⋅ 15m = 10 m; H ₂ =

N _y = 5 m

= 10 +

= 10 +

= 16,5 м.where from

= 10 +

= 10 +

= 16.5 m.

2. The volume of the blasted block - V _B ,

V _B = 60,000 m ³ .

3. The volume of drilling in the blasting unit - ∑ L ^P _C ,

= n_C ⋅

= 84 ⋅ 16,5 = 1386 м.∑

= n_C⋅

 = 84 ⋅ 16.5 = 1386 m.

,4. The output of the rock from 1p.m wells -

,

=

=

= 43,3 м³.

=

=

= 43.3 m ³ .

,5. Drilling costs -

,

= С_пм ⋅∑

= 0,34 ⋅ 1386 = 471,2 долл.

= C_pm ⋅∑

 = 0.34 ⋅ 1386 = $ 471.2

,6. The cost of blasting -

,

=

= 18000 долл.

=

= $ 18,000

приняты равным 10% от затрат на буровзрывные работы. Тогда,7. The cost of improving the quality of working the bottom of the ledge is 3 pr, the quality of working the bottom of the ledge is estimated by the number of triangular prisms formed from blasting the first row of wells. The elimination of triangular prisms is carried out by drilling and blasting cord charges. The cost of eliminating triangular prisms

taken equal to 10% of the cost of drilling and blasting. Then,

= 0,10 ⋅ З^Т, годовые затраты - ∑

,

= 0.10 ⋅ W^Tannual expenses - ∑

 ,

= П_Б ⋅

,∑

= П _Б ⋅

,

where P _B is the number of blown blocks in a year.

The annual economic effect of E _{g is} calculated by the formula:

E _g = (З ^T - З ^Р ) ⋅ V _gm ,

where V _gm is the quarry productivity in terms of rock mass, mln m ³ (in the calculations it is assumed equal to 5.0 mln m ³ ).

The results of calculations of economic efficiency are given in the table, whence it follows that one of the ways to increase the efficiency of drilling and blasting breaking rocks is to improve the design of the borehole charge. So, the recommended method of generating explosive charge in a well allows to reduce the cost of drilling and blasting by 0.1159 million dollars, which is 5.8% of the total cost of drilling and blasting. The expected economic effect was obtained on a quarry with an annual productivity of 5 million m ³ in terms of rock mass, and with an increase in annual productivity, they significantly increase. In addition, there is a real possibility of using this technical solution simultaneously in several quarries.

Table

Expected improvement of technical and economic indicators of developments from the implementation of the invention

No. p / p The name of indicators Traditional technology Recommended Technology one The annual productivity of the quarry by rock mass, mln m ³ 5,0 5.0 2 The height of the ledge, m 15.0 15.0 3 Well depth, m 18.0 16.5 four The volume of the blasted block, m ³ 60,000.0 60,000.0 5 The number of blown blocks per year 84 84 6 The volume of drilling in the blasting unit, m 1512.0 1386.0 7 The output of the rock from 1 pm well, m ³ 40,0 43.3 8 Drilling costs, USD 514.1 471.2 9 Blasting costs, USD 18000.0 18000.0 10 The cost of the elimination of the triangular prism, dollars 1851.41 - eleven The total cost of drilling and blasting, dollars 19851.41 18471.2 12 Economic effect during drilling and blasting preparation of a block for excavation, USD - 1380.21 13 The annual economic effect, dollars, with the mine productivity of the quarry - 5 million m ³ - 115937.6

Claims (1)

A method of generating an explosive charge in a well, including drilling a well, filling it with a main explosive charge, placing additional dispersed charges in the well with filling the gaps with drill material, and then initiating such charges with a detonating cord, characterized in that the main charge is placed at the bottom of the well in sleeves oriented along the sole of the ledge perpendicular to each other in four directions create an air gap between these charges horizontally tal cavity, the upper mouth of the borehole lock stopper, and an additional explosive charge in a borehole placed at a distance equal to half the height of the shoulder with the backfill material remaining wells zaboechnym space.

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