Method of blast-hole drilling ensuring preset extent of blast rock grinding

FIELD: blasting.

SUBSTANCE: method of blast-hole drilling ensuring preset extent of blast rock grinding includes drilling of explosive wells at the distance between them, depending on detonating characteristics of explosives, physical and technical properties of a rock massif, parameters of its cracking, their charging and explosion. Explosive wells are charged with explosives with specific consumption per m3 of blast rock in amount determined with account of explosive energy losses as charge explosion products expand in a well volume occupied with the charge, and also with account of losses related to the extent of the specific explosive detonation completeness in the well of the specific diameter, which are introduced into a calculation expression for a coefficient of relative operability of the applied explosive.

EFFECT: reduced volume of drilling works in drilling of explosive wells, which results in higher efficiency and reduced cost of blast-hole drilling.

3 tbl

 

The invention relates to the mining industry, in particular to methods of mass blasting ores and rocks, and can be used for open development of mineral deposits.

There is a method of drilling and blasting operations in quarries to ensure a given degree of fragmentation of the blasted rock mass, including the drilling of groups of blastholes on the distance between them is determined from the expression depending on the diameter of the charge, the detonation characteristics of EXPLOSIVES, physical and technical properties of the array parameters of fracture and size conforming piece (see Reference shooter/edited Binkowska. - M.: Nedra, 1988, s-273).

However, this method does not provide calculation results close to real obtained in specific conditions experimentally.

The closest in technical essence to the described invention is a method of drilling and blasting operations to ensure a given degree of fragmentation of the blasted rock mass, including the drilling of blastholes on the distance between them, a certain ratio depending on the diameter of the charge, the detonation characteristics of EXPLOSIVES, physical and technical properties of the rock mass, parameters of fracture, subsequent loading and blasting, is known from the patent of the Russian Federation No. 2239783.

However, the known method does not take into account the real health used CENTURIES and consequently does not make it rational specific consumption, which leads to an increase in the volume of EXPLOSIVES used at mass explosion or not the requirements to achieve the specified degree of fragmentation of blasted rock.

The invention is directed to the solution of the technical problem the optimization process of drilling and blasting operations (drilling and blasting) from the point of view of providing a given degree of fragmentation of the blasted rock with minimizing the required specific consumption used CENTURIES kg/m3.

The technical result in the application of the method is to reduce the volume of drilling operations during drilling of blast holes, which leads to increased productivity and reduced the cost of drilling and blasting.

The problem is solved due to the fact that in the method of drilling and blasting operations to ensure a given degree of fragmentation of the blasted rock mass, including the drilling of blastholes on the distance between them, depending on the detonation characteristics of EXPLOSIVES, physical and technical properties of the rock mass and parameters of fracture, loading and blasting, loading blastholes make EXPLOSIVES with a specific consumption per m3blasted rock in quantity, which is determined taking into account energy losses the CENTURIES with the expansion of the products of the explosion of the charge in the volume of the well, occupied by the charge, and also taking into account losses associated with the degree of completeness of the detonation specific EXPLOSIVES in a borehole of a specific diameter, which enter into the calculation expression ratio relative is operable CENTURIES, while the specific consumption of EXPLOSIVES is determined from the expression

where

Q - weight of the charge in the borehole, kg;

H - the height of the ledge, m;

- the content in the array of structural units with a maximum size of G>0,15;

Vnm- estimated minimum output oversized, %;

VN.- specified output oversized, %;

G>0.15 m is the maximum size of the piece within the crushing zone with radius R (conforming the size of the pieces);

- the coefficient of relative health used CENTURIES in relation to another (reference) EXPLOSIVES;

- the average distance between cracks in the array, m;

d - diameter borehole charges, m;

Δ is the density of the loading wells, kg/DM3;

the amendment takes into account relative (diameter) length of borehole charges;

M is the sequence number of soil classification SNiP.

In the proposed method of drilling and blasting operations to ensure a given degree of fragmentation of the rock mass (determined by the percentage of output bliss is Arita) used the basic provisions, known from theory and practice of conducting drilling and blasting, taking into account the influence of individual parameters passport drilling and blasting on the results of explosions, a change which allows you to adjust the crushing in a wide range, such as the specific consumption of EXPLOSIVES and define its parameters, including the diameter of the charge, net of their location and the type of EXPLOSIVES.

Also taken into account physico-technical properties of the rock mass, the parameters of fracture. Requirements to the results of blasting at quarries include compliance with work safety (rational specific consumption), ensuring sufficient loosening of the rock mass at the foot of the developed ledges, as well as the necessary fragmentation of the rock mass to ensure productive work loading and transport equipment.

In the basis of the method was based on the well-known concept used in the calculations passport drilling and blasting the relative health of the applied concrete CENTURIES, determined from the ratio

where

f - relative performance;

QCCis the calculated heat of explosion applicable CENTURIES, kcal/kg;

Qeis the calculated heat of explosion of the reference CC, kcal/kg;

VCC- estimated volume of gases of explosion used BB, DM3/kg;

Ve- estimated volume of gases of explosion reference is In, DM3/kg.

Experimental use when conducting blasting emulsion EXPLOSIVES showed that TNT coefficient (equivalent) BB calculated heat of explosion of reference and applicable CENTURIES, as well as the formula (1) did not meet the actual health of emulsion explosive substances, as they do not take into account the fundamental differences between granulated EXPLOSIVES and emulsion EXPLOSIVES, which differ in density and detonation properties and, as a consequence, difference:

a) the energy loss during the expansion of the energy of detonation products;

b) energy losses due to different degrees of completeness of the process of detonation of the charges of different diameters.

This often leads to errors in the rational calculation of specific consumption and, as a consequence, the required amount of EXPLOSIVES per blast, which leads to the calculation of the inflated safety distances for blasting works.

Taking into account the above principal differences between proposed to clarify the formula for calculating the relative efficiency, which should be determined taking into account energy losses CENTURIES with the expansion of the products of the explosion of the charge in the well volume occupied by the charge, and also taking into account losses associated with incomplete detonation of specific EXPLOSIVES in the hole of specific diameter. These losses determine the relative health of this the pubic CENTURIES, entering in the calculation of the expression ratio relative is operable VV:

where

Vused BB- estimated volume of gases of explosion used BB, DM3/kg;

Vreference BB- estimated volume of gases of explosion reference BB, DM3/kg;

the actual heat of the explosion, Kcal/DM3;

ρ is the density used or reference explosives, kg/DM3;

Qsettlementis the calculated heat of explosion of reference or used explosives; kcal/DM3;

Kd- the indicator of the ratio of the critical diameter (steel shell) used EXPLOSIVES to the diameter of the charge, which is found by the formula

This indicator identifies the relative supply reliability and completeness of the process of detonation of the substance in the well conditions specific diameter. The scope of formula for diameters charge of 100 mm or more.

Efficiency - the efficiency of the explosion, reflecting the loss of energy during the expansion of the detonation products to the amount of explosive charge in the borehole, obtained on the basis of the correlation between the ratio of the amounts of charge and welland loss of energy of the explosion when the expansion of the detonation products of the original volume, occupied by the explosive in the borehole, excluding its porosity, the volume of wells

The results of the calculation of the coefficient of relative efficiency and coefficient of the proposed method are given in table 2.

Required specific consumption of EXPLOSIVES (kg/m3) to achieve the specified degree of fragmentation of the shattered rock mass (output oversized, %) is determined from the expression

where

Q - weight of the charge in the borehole, kg;

H - the height of the ledge, m;

- the content in the array of structural units with a maximum size of G>0,15;

Vnm- estimated minimum output oversized, %;

VN.- specified output oversized, %;

G>0.15 m is the maximum size of the piece within the crushing zone with radius R (conforming the size of the pieces);

- the coefficient of relative health used CENTURIES in relation to another (reference) EXPLOSIVES;

- the average distance between cracks in the array, m;

d - diameter borehole charges, m;

Δ is the density of the loading wells, kg/DM3;

the amendment takes into account relative (diameter) length of borehole charges;

M is the sequence number of soil classification SNiP.

When real is the organization of the proposed method of blasting with the aim of improving safety and efficiency of drilling and blasting, when calculating the parameters of the explosion, the approach applied in the evaluation of explosive properties EXPLOSIVE based on the number of determining their efficiency factors such as the efficiency of the explosive, its density (saturation per unit volume), the critical diameter of detonation used substances affecting the reliability of the downhole detonation charges and high efficiency of the explosion.

As a result of this approach obtained the generalized characteristic explosive properties used EXPLOSIVES, which allows to estimate their actual destructive ability, proven by many years of practice, emulsion EXPLOSIVES.

For optimum mass of EXPLOSIVES per blast is introduced is identical to an existing conversion factor, which is calculated by the formula

The results of the calculation of the actual heat of explosion is widely used CENTURIES, the coefficients of relative healththese CENTURIES against granulator (reference BB), as well as conversion factorsobtained by the proposed method are given in table 2.

Required specific consumption of EXPLOSIVES kg/m3necessary to achieve the specified degree of fragmentation of the blasted rock (output oversized, %)set the ut taking into account energy losses CENTURIES with the expansion of the products of the explosion in the volume, occupied by the charge in the well, and also taking into account losses associated with the degree of completeness of the detonation specific EXPLOSIVES in the hole of a certain diameter.

The described method of drilling and blasting operations in the application of emulsion EXPLOSIVES can reduce the amount of blast hole drilling by optimizing the specific consumption of EXPLOSIVES kg/m3necessary to achieve the specified degree of fragmentation of blasted rock.

So, based on calculation results by the given method (Graduation) (the results are shown in table 1), the application of emulsion EXPLOSIVES must spend 30% more than granulate (assumed equivalent). However, the experience of industrial applications have shown that these calculations lead to excessive use of emulsion EXPLOSIVES. Industrial tests were conducted confirmed the correctness of the proposed method of calculation and showed that actually the number of required CENTURIES is much lower (see table 2).

To determine the effectiveness of the proposed method of blasting operations were carried out pilot tests on the branches of JSC "Coal company Kuzbassrazrezugol" in 2009, replacing "Granulite yn-1 in dry and slaboobvodnennyh wells with drilling and blasting parameters calculated by the existing method, the emulsion explosive "Siberia-1200" option is mi drilling and blasting, calculated by the proposed method.

According to the conditions of the experiment were Oborony control and experimental plots of the block with existing drilling and blasting parameters and defined in accordance with the proposed method, in which the output characteristics (output size of the piece more than accounted for) was estimated values determined from the nature of the energy release BB on the proposed method.

Comparative data from experimental plots on one of the blocks is shown in table 3. The data obtained show that the application of the proposed method achieved a significant reduction in the volume of drilling operations during drilling of blast holes, which leads to increased productivity and reduced the cost of drilling and blasting.

Table 1
The results of the calculation of TNT equivalents and conversion factors used for CENTURIES under the existing method of calculation of rational values of specific consumption of EXPLOSIVES used in a number of large mining enterprises of Kuzbass developed STU
№ p/pNaimenovanie BBThe heat of explosionThe Density Is, kg/DM3TNT equivalentThe conversion factor
kJ/kgKcal/kg
1Granulator*3733893100011,0
2TNT (scaly)33868109200,901,11
3Granulit yn-1, yn-1A37108809500,911,10
4Sibiri258561712000,771,30
* TNT equivalent calculated by the heat of the explosion relative to the TNT in water-filled state (Granulator).

Table 3
Comparative table of the drilling and blasting parameters on an existing (control plot) and the proposed (experimental section)
Data on the exploded blockControl plotExperimental section
Start date of importation01.11.08
Date of explosion05.11.08
Horizon+255
Profile line48-5146-48
Geological characteristics of the host rocksSiltstone fine-grained 90%,
Sandstone medium-grained 10%
Fortress on a scale professional Protodiakonov11
Volume VGM total, thousand m3 131, 5mm
Volume UGM, thousand m3on the experimental plot block82,549,0
The depth of wells m2-12m
Intermediate detonatorIV⌀6O mmFRI-P
FRI-P
The way of initiationSINV-With-500
The number of BB, t56,738,0
The volume of drilling, m Pogue.29351360
Output oversized, %1,931,74
The specific consumption of EXPLOSIVES, kg/m30,8210,776

The method of drilling and blasting operations to ensure a given degree of fragmentation of the blasted rock mass, including the drilling of blastholes on Russ is in nformation between them, depending on the detonation characteristics of EXPLOSIVES, physical and technical properties of the rock mass, parameters of fracture, loading and blasting, characterized in that the loading blastholes make EXPLOSIVES with a specific consumption per m3blasted rock in quantity, which is determined taking into account energy losses CENTURIES with the expansion of the products of the explosion of the charge in the well volume occupied by the charge, and also taking into account losses associated with the degree of completeness of the detonation specific EXPLOSIVES in a borehole of a specific diameter, which enter into the calculation expression ratio relative is operable CENTURIES, while the specific consumption of EXPLOSIVES determined from the expression:

where Q is the mass of the charge in the borehole, kg;
H - the height of the ledge, m;
- the content in the array of structural units with a maximum size of G>0,15;
Vnm- estimated minimum output oversized, %;
Vn- specified output oversized, %;
G>0.15 m is the maximum size of the piece within the crushing zone with radius R (conforming the size of the pieces);
- the coefficient of relative health used CENTURIES in relation to another (reference) EXPLOSIVES;
- the average distance between cracks in the array, m;
d - diameter borehole dawn is s, m;
Δ is the density of the loading wells, kg/DM3,
the amendment takes into account relative (diameter) length of borehole charges;
M is the sequence number of soil classification SNiP.



 

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EFFECT: enhanced efficiency of sloping.

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FIELD: mining industry, applicable in driving of horizontal workings.

SUBSTANCE: compensation and blast holes are drilled in a rock mass over the entire length of the raise. The blast holes are charges partially or completely, and they are subjected to a short-delay blasting into compensation holes and then the formed compensation cavities. The interval of slowing-down between the holes blasted in succession, depending on the detonation characteristics of the explosive, charge diameter, physico-technical properties of the rock mass, height and diameter of the newly formed compensation cavities should provide for breaking of the rock from the mass and full outburst of the rock mass from the cavity, i.e. to prevent the pressing effect of the rock mass in the contour of the raise.

EFFECT: determined the interval of slowing-down between the holes blasted in succession with prevention of the rock mass pressing in the contour of the raise, which allows to increase the height of the blasted section and enhance the physico-technical properties of the raise driving.

1 dwg, 1 ex, 2 tbl

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