Method for obtaining a preset crushing ratio of fissured mountain mass and the required coefficient of heading advance per round to shot holes length ratio
SUBSTANCE: method comprises shot hole or bore-hole drilling, loading them with explosive material so that the bottom part of the shot hole the explosive material density or energy concentration would exceed the one in the wellhead of the shot hole. The mass of explosive material charge in the bottom part of the shot hole is calculated mathematically, depending on the line of least resistance value, the diameter of explosive material charge, fissure parameters and physical and technical mountain mass parameters, the rock pressure and detonation velocity of the explosive material.
EFFECT: enhanced efficiency and safety of drilling and blasting operations alongside with ore beneficiation efficiency.
1 dwg, 1 dwg
The invention relates to the mining industry, in particular the layer system of mining with the use of drilling and blasting operations.
Known method for improving the quality of the crushing mountain massif of the explosion in open pits, according to which the wellhead is BB with the lowest specific energy, and at the bottom of the wells CENTURIES with high specific energy, or by drilling at the bottom of the borehole boiler extensions .
However, the author is not listed, what is the diameter of the boiler in the area of the enlargement or what explosive weight (length of the explosive charge) with high energy, which you can choose depending on the physical and technical properties of rocks, detonation and geometrical parameters CENTURIES.
The closest technical solution is the method of loading holes with providing various concentrations of energy explosion in the bottom and core part of the bore-hole . The length of the bottom of the bore-hole is 1/3 the depth of the hole, and the density of loading of 0.85 g/cm3for Ammonites, which creates a seal CENTURIES by zabojnik. The concentration of EXPLOSIVES in the core part is 0.5 kg/m, which is achieved by leaving an air gap and part of the bore-hole for tamping.
However, the bumper blast hole charges of EXPLOSIVES used in underground mining of ore, as a rule, charge 2/3 from glinister. That is half of the explosive charge will have a density of 0.85 g/cm3(high energy density), and the other half of 0.45-0.55 g/cm3(low energy density) due to the presence of the air gap.
In addition, when calculating the mass of the charge in the bottom part is not taken into account the line of least resistance (LNS), the diameter of the explosive charge fracturing parameters and physico-technical properties of the rock mass, detonation characteristics CENTURIES and size of rock pressure.
Method for obtaining a given degree of fragmentation of the fractured rock mass and the desired utilization of the bore-hole (KISH) explosion, including the drilling of boreholes or wells, loading EXPLOSIVES so that at the bottom of the hole density CENTURIES or concentration of energy were greater than in the mouth part of the bore-hole, characterized in that the mass of the charge sealed or vysokobarnogo CENTURIES at the bottom of the borehole is determined taking into account the magnitude LNS, charge diameter, fracturing parameters and physico-technical properties of rocks, the ground pressure, and velocity of detonation of EXPLOSIVES from the expression
W - the line of least resistance or the distance from the borehole to the electric circuit of the cavity, m;
dethe average size of the individual array, m;
F - measure of cracks is vitasti array;
d3- the diameter of the explosive charge, m;
µ - coefficient of friction between the separateness of the array;
P - value rock pressure between the air holes and Ironman cavity, PA;
D - speed detonation of EXPLOSIVES, m/s;
ν is the Poisson's ratio of rock.
The proposed method can provide high KISH due to seal CENTURIES and determine the mass of the bottom part of the explosive charge needed to overcome LNS. Also, do not seal CENTURIES in the mouth part can reduce the output of fines in the blasted rock mass, which increases the efficiency of enrichment, for example, uranium ores. The weight of CENTURIES with a high concentration of energy (due to the seal or the use of more powerful EXPLOSIVES) in the bottom part is determined taking into account the magnitude LNS, charge diameter, fracturing parameters and physico-technical properties of the rock mass, the ground pressure, and velocity of detonation of EXPLOSIVES. This allows you to increase security, efficiency blasting and ore.
The method consists in the following. Low mass of the explosive charge in the bottom part is not sufficient for blasting the rock mass from the array when the layer extraction of ores. Therefore, in the newly formed face appear "glasses", which reduces the efficiency of blasting. Inflated the weight of the explosive charge at the bottom leads to pieism is leczeniu ore and reduce the effectiveness of x-ray radiometric enrichment, for example, uranium ores.
The mass of the explosive charge in the bottom part, necessary for the conditions of the array with the maximum KISH, you can determine based on the first law Newton's stresses. The compressive stress occurring in the mountain at the moment of explosion of the explosive charge at a distance from a charge equal LNS should be equal to the sum of the frictional forces created by the rock pressure and lateral spreading of rock. Mathematical conclusion, see Appendix 1.
Output pereizluchennykh factions in the mouth part of the bore-hole with a size less than 40 mm (VMsignificantly depends on the density of loading (ρinand the velocity of detonation of EXPLOSIVES D. That is, VMdirectly proportional toand D2.
The increase in the density of loading CENTURIES from 600 to 850 kg/m3will lead to the increase of fines in 2 times in the mouth part of the bore-hole. Use instead of Ammonite EV with a value of D=4,2·103m/s, detonite with D=5,1·103m/s will lead to an increase in output of fines 1.47 times in the mouth part of the bore-hole. Mathematical conclusion VMgiven in Appendix 2.
The proposed method is as follows. The Poisson's ratio of rocks to determine the stage of exploration by known methods. The detonation speed D and the diameter of the explosive charge d3determine, using reference books. The value of the priori pressure in the area of the conducting layer Zachodni define or geophysical methods, or the well-known formula P=ρgH, where ρ is the bulk density of the rock mass, kg/m3., g - gravitational acceleration, m/s2N is the depth from the surface of the earth, m, the value For the concentration ratio of rock pressure in the area of the blow hole, usually it is equal To=2-3. Values f, µ determined from the deon the table
The value LNS W is determined by the passport drilling and blasting. For Ironman holes W is equal to the distance between them to the bumper - the minimum distance from the borehole to the surface of the electric cavity. For contouring - the minimum distance from the borehole to the exposed surface of the formed cavity.
The value of dedefine directly on the bottom output. Substituting
Islandia values of the parameters in formula (1), get the value of Q. Next, in the layer section of the Buryat electric, pneumatic and counting the holes. All boreholes charge. When using the same type BB ammo in the bottom part of the maximum compacted by power. The explosive cartridges in the mouth part is introduced into the holes without seals. When using different types of EXPLOSIVES in the bottom part of introducing more efficient CENTURIES (for example, demonic M, ammonal 200), priustevye less workable - Ammonite IV.
Next make installation network and explode in accordance with the passport drilling and blasting.
Example. Mine has a "Deep" JSC PIMCU in the array hard-shot grounds granites with the size of the separateness of 0.3-0.5 m produce ore extraction system tunneling layer extraction with hardening bookmark. Drilling the holes and blow by the conventional methods, charging boreholes Ammonite IV and podbrezova all the cartridges. Measurements of the results was performed by determining KISH (along the length of the "glasses") and the entry of small fractions (-40 mm) photopolarimetric method. The results after five cycles of explosives: KISH amounted to 0,7-0,85, output fraction - 40 mm was 37-45%.
Next it was decided to use the new method. The numerical values of the parameters in the formula (1): W=0.7 m; de=0.4 m; f=8 (see table); d3=0.04 m; the value of rock pressure at H=500 m, ρ=2,5·103kg/m3, g=9.8 m/s2, K=2 is equal to P=2,46·107PA; D=4,2·103m/s; ν=0,25. Substituting Chi is certain value in the formula (1), get Q=0,24 kg
Calculations by the formula (1) showed that the mass of the bottom sealing portion of the explosive charge must be equal to 0.24 kg is approximately one cartridge Ammonite IV. Subsequent experimental work in hard-shot grounds granites with a mass at the bottom of the charge, equal to 0.2-0.25 kg (1 cartridge), and the density of the loading mouth part of the charge (3-4 cartridge weight 0,6-1,0 kg, diameter 32 mm), is 0.64·103kg/m3revealed: KISH was 0.8-0.9, the output fraction - 40 mm 28-35%.
Thus, application of a new method allowed us to increase the KISH and reduce the yield of fines that helped improve the efficiency and safety of drilling and blasting operations, and the effectiveness of x-ray radiometric separation.
Sources of information
1. Efremov AM Preparation of rock quarries. - M.: Nedra. - 1980. - S (rice,m), s.
2. Technique and technology of blasting at mines // ABT. Heptaminol, Lowdose, WTO and others - M.: Nedra. - 1978. - S-187.
Appendix 1. Theoretical calculation of the mass of the explosive charge at the bottom of the borehole to increase the KISH
The greater utilization of the borehole when the descending layer excavation of ores improves the efficiency of mining operations and security level. To improve KISH recommended to condense CENTURIES at the bottom of the borehole or to use it more workable CENTURIES. However, you must determine the mass is In, sufficient for reliable blasting of the mountain massif in Ironman cavity. The underestimation of the mass of EXPLOSIVES will not receive the specified KISH, overstatement to pereseleniu ore, which has a negative effect on the enrichment, for example, uranium ores.
The mass of the explosive charge in the bottom part, sufficient for reliable blasting of the rock mass, can be calculated from the first law Newton's stresses. The compressive stress σin(r), resulting in a mountain range at a distance r (r=W, where W is LNS), must be equal to or exceed the sum of the frictional forces created by the rock pressure (σgand side thrust rocks (σbr) on the electric circuit cavity
According to  for spherical explosive charge
where ρinD, d3accordingly, the density of the explosive charge, the detonation speed CENTURIES, the diameter of the explosive charge; W - LNS; de, F -, respectively, the average size of the piece separately in a rock mass, a measure of the deformability of jointed rock mass, π=3,14.
According to 
where µ, ν, respectively, the coefficient of friction between the pieces of rock in shear, Poisson's ratio of rock, P - value rock pressure between the air holes and Ironman cavity.
Substituting (2) and (3) in (1), we obtain
Multiplying the left and right part of (4)get the formula to determine the mass of the explosive charge required for the release of the rock mass of Ironman cavity
The energy of a cylindrical explosive charge from the bottom part extends from spherical when considering processes at large distances (15-30 diameter of the explosive charge) . In this case, l3=4d3. Then (5) can be rewritten in
Annex 2. The output calculation pereizluchennykh fractions (-40 mm) when changing the detonation characteristics of CENTURIES.
Output pereizluchennykh fractions with size less than 40 mm can be determined from geometrical considerations by the formula
RMis the radius of the zone pereizluchennykh fractions near the explosive charge is defined in , m;
N is the number of holes in the bottom layer Zachodni;
S is a sectional area of the layer zagadki, m2;
ρinthe density of loading, kg/m3;
C is the speed of longitudinal waves in the rock specimen, m/s;
dM- the maximum size of a piece pereizmennoy rock mass, dM=0.04 m;
σp- the tensile strength of a rock specimen in gap, PA.
The analysis of the formula (7) after substitution in (8) shows that the output of small fractions of VMthe nternet is proportional to D 2and ρ2.
1. Tyupin NR. Geometrization of crushing zones of fractured array parallel to the axis of the explosive charge. // Izvestiya Vuzov. Mining magazine. - 1985, №1, - P.41-45.
2. Tyupin NR. Improving the efficiency of Geotechnology using explosive energy during the deformation of fractured strained rocks. // Thesis for the degree of doctor of technical Sciences - Moscow: VNIPI promtechnologii. - 2002. - Pp. 102, 104.
3. Pokrovsky GI Dependence of the form of range of the explosion on the shape and disposition of the charges. - In the book. Explosive business. - M.: Nedra. - 1964. No. 54/11. - S.
The method of obtaining a given degree of fragmentation of the fractured rock mass and the desired utilization of the bore-hole (KISH) explosion, including the drilling of boreholes or wells their loading EXPLOSIVES so that at the bottom of the hole density CENTURIES or concentration of energy was greater than in the mouth part of the bore-hole, characterized in that the mass of the charge sealed or vysokobarnogo CENTURIES at the bottom of the borehole is determined taking into account the magnitude LNS, charge diameter, fracturing parameters and physico-technical properties of rocks, the ground pressure, and velocity of detonation of EXPLOSIVES from the expression
W - the line of least resistance or the distance from the borehole to contact the RA Ironman cavity, m;
dethe average size of the individual array, m;
F is the indicator of fracturing;
d3- the diameter of the explosive charge, m;
µ - coefficient of friction between the separateness of the array;
P - value rock pressure between the air holes and Ironman cavity, PA;
D - speed detonation of EXPLOSIVES, m/s;
ν is the Poisson's ratio of rock.
SUBSTANCE: suspended well stem comprises flat elements and an elastic link. At the same time flat elements are made as two hingedly joined half-discs joined to each other, length of each equals 0.55-0.7 dw, and width - 0.65-0.9 dw. At one side each element is rounded, following the well circumference. A rope is fixed to the hinged joint, so that the hinged joint is arranged at the bottom.
EFFECT: higher operational reliability of the device, intensified process of rocks grinding, reduced specific consumption of explosive, higher quality of rock mass grinding, simplified and cheaper design.
SUBSTANCE: during development of arrangement diagram of bore pits the location points of bottoms of bore pits are arranged on explosion plane on bottom-hole of set of bore pits. Programme product of design of arrangement diagram of bore pits determines absent parametres of bore pits considered from bottom-hole of set of bore pits to navigation plane. Programme product is capable of determining initial location point of bore pit and direction of bottom-hole. Programme product also makes explosion technical calculation of arranged bore pits.
EFFECT: method and programme product for development of arrangement diagram of bore pits is improved.
25 cl, 20 dwg
SUBSTANCE: location of first queue wells is shifted in relation to last queue wells of the previous blast of current horizon and wells of higher horizon, and the location of next queue wells is shifted in relation to wells of previous blast of higher horizon.
EFFECT: increase of drilling-and-blasting operations effectiveness ensured by decrease of wells waste due to rock falling, improvement of rock crushing quality and bench toe working out.
3 tbl, 4 dwg
SUBSTANCE: invention relates to blasting and may be used in mining industry in blasting of lengthy pieces of rocks of various strength. Invention consists in the fact that well blasting is carried out with number of wells in a row equal to 5 and with delay between sections equal to (10÷15)×a ms, where a - distance between wells in a row, wells in a wedge explode relative to each other with the delay equal to (15÷25)×b ms, where b - distance between rows of wells, besides, at first well is exploded, which is arranged in the top of wedge, and then - in the order of moving away from top of wedge.
EFFECT: reduced height of heap of exploded rock mass, less throwing of exploded rock mass, reduction of seismic effect from mass explosion and increased quality of rock mass grinding.
SUBSTANCE: in the proposed method there defined is the quantity of air supplied to the dead-end underground working ventilated by infusion method. EC charge with diametre not less than 50 mm and length not less than 6 charge diametres is blasted in steel shell with wall thickness not less than 5 mm in test room, which is created in the underground working by means of isolating cross-piece that has a hole for ventilating air output. After explosion ventilating air is exhausted and with the aid of gas-analyser there performed is constant measurement of toxic gases concentration till the decrease of their contents up to gas-analyser threshold response and gaseous air pollutants are calculated. Note that additionally at explosion moment there measured is EC charge detonation speed for detonation process completeness control.
EFFECT: provision of defining of explosives gaseous air pollutant at the places of their use.
1 tbl, 6 ex
SUBSTANCE: invention can be used in mineral resource industry for testing of industrial explosives (EC) made at the places of their use. The proposed method includes location of EC charge into shell cavity, EC charge blasting in it, defining the volume of extended cavity and calculation of relative working efficiency of EC charge. As the shell there used is steel seamless pipe with diametre not less than 50 mm, wall thickness not less than 5 mm and length not less than 10 charge diametres. Over the pipe at a distance of 0.54-0.60 of charge length away from initiation beginning there tightly arranged is gauging ring made of steel 45 with diametre not less than 150 mm, height 30-50 mm. Note that there performed is the blasting of EC tested charge and 6ZHV ammonite charge as reference one and there defined are the changed volumes of inner cavities of gauging rings of tested and reference EC charges. The calculation of explosive working capacity is performed in relation to the volumes of inner cavities of gauging rings of tested and reference EC charges after explosion. Note that additionally there measured is EC charge detonation speed for detonation process completeness control.
EFFECT: provision of relative working capacity defining of modern industrial large particle explosives.
1 tbl, 12 ex
SUBSTANCE: method for destruction of solid rocks or concrete, includes installation and driving of devices filled with mixture of substances in blast holes, initiation of combustion reactions in devices in non-detonation mode, accompanied by development of appropriate pressure in blast holes. Non-detonation mode of combustion is provided by application of mineral oxidiser in the form of pellets with size of 0.1-5.0 mm, which fills up to 95% of sealed device volume, besides prior to installation of device into blast hole, device cover is opened, liquid hydrocarbon fuel is poured into it in stoichiometric amount, cover is closed, and device is shaken. In version of method, dry sealed blast holes are filled with mixture of mineral oxidiser in the form of pellets with size of 0.1-5.0 mm with liquid hydrocarbon fuel. Initiation of combustion reactions is done by means of initiation facility arranged in the form of thin exploding wire, connected to source of high-voltage electric pulse.
EFFECT: method makes it possible to considerably simplify operations at site of works performance, to increase reliability of method actuation, its safety, to reduce cost of works and therefore increase landmine effect from method application.
SUBSTANCE: method includes drilling vertical main and additional wells, besides selection of explosive for charging of additional wells is done by value of explosive detonation speed identified from the ratio with account of explosive detonation speed for charging of additional wells D0, m/s; ultimate tensile strength of solid inclusion rocks, Pa and ultimate tensile strength of host rocks, Pa. Additional wells are drilled with depth with account of solid inclusion soil elevation in depth of the main wells, between which appropriate additional well is located - m; number of the main wells, between which according additional well n is located, and diameter of additional wells - dwell∂, m.
EFFECT: improved efficiency of crushing of various solid inclusions with account of the main properties of host rocks, inclusions and applied explosives.
2 cl, 2 dwg, 1 ex
SUBSTANCE: device for destructing rock lumps consists of explosion substance in shell in form of elongated cumulative charge (ECC) 1 with metal foil placed in cumulative recess of ECC, of fuse out of initiating explosion substance (ES) in form of cartridge, and of "П"-shaped case made of split parts with air pockets 12 in vertical walls; also pockets are connected to chamber through orifices 7. The device contains a hold down fixture packing a two-part gasket 14 and 15 between a lump and the device. The "П"-shaped case is made of several parts out of materials of different strength and connected with bolts: main, several additional ones and un upper one.
EFFECT: raised efficiency of rock lumps destruction.
SUBSTANCE: benches are developed by pillar and peripheral splits, wells are drilled within the limits of peripheral split, charged and exploded, peripheral split is developed as advanced relative to pillar split, main and auxiliary wells are drilled in massif of pillar split as horizontal along pillar, arranging a row of auxiliary wells higher than the middle of bench, wells are charged by their stemming with low-density material on both sides and exploded.
EFFECT: reduced amount of rocks dropped to lower arranged horizons, decreased volumes of additional handling related to lifting of exploded rocks dropped at lower arranged benches to the horizon of their primary location, increased efficiency of mining works.
1 ex, 2 tbl, 8 dwg
FIELD: mining art, in particular, open-pit mining of mineral resources by high benches.
SUBSTANCE: large-diameter single holes are replaced by a pair of divergent holes of a smaller diameter, in which one hole is always vertical, and the other one is inclined towards the bench; the single holes of the larger diameter are replaced with a pair of divergent bundles of parallel converged holes, in which one bundle is vertical, and the other is inclined towards the bench; the single holes of the larger diameter are replaced with a pair of divergent holes of a smaller diameter, in which one hole is vertical, and the other is inclined towards the bench and positioned in the vertical plane parallel with the first one and distant from it by 1-2 hole diameters; the single holes of the larger diameter are replaced by a pair of divergent bundles of parallel converging holes, in which one bundle is vertical, and the other is inclined towards the bench and positioned in the vertical plane parallel with the first one and distant from it by 1-2 hole diameters.
EFFECT: enhanced efficiency of blasting of the benches.
7 cl, 6 dwg
FIELD: mining industry, applicable in opencast mining of mineral resources and hydraulic engineering.
SUBSTANCE: the method for formation of a deep-hole charge of a multi-component mixed explosive consists in impregnation of porous and crystal ammonium nitrate with liquid petroleum product and placement of the obtained explosive in the hole, formation of the mentioned deep-hole charge in its extension is accomplished with sections of various density of the explosive depending the physico-mechanical properties of the rocks located in the length of the hole, varying the density of the explosive by varying the mass percent relation of the quantity of granules of porous and crystal ammonium nitrate in the explosive compound, the mass percent of a granule of porous ammonium nitrate is within 54.5 to 71.5, a granule of crystal ammonium nitrate is within 20 to 40, liquid petroleum product - within 5.5 to 8.5, the granules of porous ammonium nitrate are used with sizes of 2.5 to 4.5 mm, and those of crystal ammonium nitrate - 0.7 to 1.3 mm, mineral oil is used as petroleum product.
EFFECT: provided optimized destruction of the rock in opencast mining of mineral resources and in building blasting operations.
FIELD: mining industry, applicable for slanting of high benches at development of magmatic deposits of mineral resources by open pit.
SUBSTANCE: the method includes drilling of contour holes for formation of a screening peephole, buffer and breaking holes to a depth corresponding to the height of one working subbench with a redrill, the middle row of breaking holes is made with an incomplete drill, charging of the openings and their blasting, dispatch of the rock, after blasting first of outline openings, for formation of the screening peephole, and then of breaking holes and mucking of the rock, similar operations are performed on the underlying subbench of the lower high bench, at the development of the lower high bench, the development of the upper and lower benches is conducted by doubling of the working subbenches, at the development of the lower subbench of the upper high bench the outline openings are drilled to the whole height of the doubled bench, the buffer openings are drilled at a distance of 12 to 13 diameters of the charge from the outline openings and to a depth at least corresponding to the height of one working subbench with a redrill equal to 6-8 diameters of the charge, the first and last rows of the breaking holes are drilled with a redrill, equal to 4-5 diameters of the charge, and the incomplete drill of the middle row of the breaking holes makes up 7-8 diameters of the charge, after blasting of the buffer and breaking opening and mucking of the rock a crest is formed, from whose surface on the side of the slope outline and buffer openings are drilled, the first ones - to the height of doubled subbenches, and the second ones - to the height at least of one lower working subbench, then the breaking openings to the same height as in the above - and underlying subbenches and for production of a natural protective bank on the upper section of the lower high bench in the section of the berm the formed ridge is liquidated by drilling, charging and blasting of the openings of small diameter and depth.
EFFECT: enhanced stability of high benches on the outline of the open pit.
2 cl, 3 dwg, 1 ex
FIELD: mining industry, applicable at blasting of rocks on the ground surface, at blasting of ores in the underground conditions and driving of underground open pit minings.
SUBSTANCE: the method for drilling blasting of rocks includes drilling of boreholes with subsequent their loading with explosive charges, short-delay blasting and registration of seismic oscillations on one block. Then, the zone with the maximum quantity of simultaneously blasted deep-hole charges on this block is determined according to the amplitude of speed exceeding the preset level on the seismograph. After that the intervals of operation between the adjacent charges on the next block are increased with due account made for the obtained results of measurements on the previous block.
EFFECT: provided the necessary degree of rock crushing at an allowable level of seismic action on the environment.
4 dwg, 1 ex
FIELD: mining of mineral raw material, applicable at opening of workings or manbreaking.
SUBSTANCE: a trapezoidal recess is made in the cartridge-shape charge of blasting destruction obliquely to the longitudinal axis of the charge. The recess is positioned at the cut of the generating line and the change end face. In the charged blast-hole (or well) the recess is directed towards the non-charged blast-hole or towards the additional exposed plane.
EFFECT: enhanced utilization factor at opening of workings and holes at mass breaking.
SUBSTANCE: method comprises making well charge of individual members of the blasting agents that receive one or several strikers. The members are separated with spaces filled with a liquid with a density of 800-1400 kg/m3. The strikers are actuated so that the detonation of blasting agent is completed simultaneously in the bulk. The height of the active section of the charge of blasting agent interposed between the boundaries of the liquid and location of the striker are calculated from the formula proposed.
EFFECT: enhanced efficiency.
7 cl, 3 dwg
FIELD: mining industry; openpit mining of ferruginous quartzites.
SUBSTANCE: method is proposed in two versions. According to first version, method includes drilling at bench parallel rows of vertical boreholes at angle β relative to strike line of layers determined by the following relationship: β=arc cos (cos 45°-sinγ·cosα)/(sinα·cosγ), where α is angle of dip; γ is angle between plane of blast wave front and vertical. Then, boreholes are charged with explosive followed by tamping at simultaneous blasting in each row for forming inclined compression blast wave. According to second version, proposed method includes drilling parallel rows of vertical boreholes at angle β relative to strike line determined by the following relationship: β= arc cos (cos 45°-sinγ·cosα/(sinα·cosγ)±ψ, where α is angle of dip; γ is angle between plane of compression blast wave front and vertical; ψ is angle of turn of compression blast wave front around vertical axis relative to strike line which is determined as follows: ψ=arc sin(υel·t/L) where υel is velocity of propagation of elastic wave in mass; t is interval of time between blasts of charges in first and last boreholes of row; L is length of this row of boreholes; sign of angle ψ is selected that angle between line of each row of boreholes and line of crest of bench of shoulder is close to or is equal to 90°, after which boreholes are charged with explosive followed by tamping and successive blasting in each row forming inclined compression blast wave.
EFFECT: enhanced efficiency of softening the ore.
3 cl, 6 dwg, 3 ex
FIELD: mining; construction industry; methods of breaking rocks from massifs with lenticular permafrost massifs.
SUBSTANCE: the invention is pertaining to the field of mining and construction and is intended for breaking rocks from massifs with the lenticular permafrost spots. The technical result is improvement of the quality of crushing of rocks with the lenticular permafrost spots and a capability to control the sizes of the crushing over the whole volume of the rocks shooting. The method provides for boring of the downward primary and additionally boreholes, their charging with explosive charges (explosives), stemming of boreholes and firing of charges of explosives. At that while boring the primary boreholes in the case of presence of the lenticular permafrost spots determine their contours in plane and marks of the roofing and soil of these lenticular permafrost spots by the depth of the boreholes. The additional boreholes they drill inside the contour with a crossover of the indicated lenticular permafrost spots, but not deeper than the primary boreholes, At that determine marks of the roofing and soil of the lenticular permafrost spots by the depth of the additional boreholes, and at a charging of the additional boreholes the charges of explosives place inside the crossing lenticular permafrost spots.
EFFECT: the invention ensures improvement of the quality of crushing of rocks with the lenticular permafrost spots and a capability to control the improvement of the quality of crushing of rocks with the lenticular permafrost spots and a capability to control the sizes of the crushing over the whole volume of the rocks shooting.
8 cl, 2 dwg, 4 ex
FIELD: mining art, applicable for mining by open method in rocky and semirocky rocks at placing of high benches on planned contour.
SUBSTANCE: the method consists in collaring of inclined holes from the upper bench to be height of a doubled bench, for production of a cut-off slot at formation of the upper inclined part of the bench and contour vertical holes from the intermediate bench to the same depth for formation of the lower vertical part of the bench, loading and blasting. The novelty in the method is in the fact that the drilling of holes of the contour row from the intermediate bench is performed in three stages: initially in the first stage drilled is the part, of inclined holes from the initial to the final point of the section of sloping with one direction of inclination, in the second stage drilled are the inclined holes of the contour row having the same inclination and the same distance between the holes as in the first stage, but in the contrary direction, in the third stage between the mentioned inclined contour holes drilled are vertical contour holes, the inclined holes of the contour row are loaded by a permanent charge from the face to the mouth of the holes, and in the vertical contour holes positioned between the inclined contour holes, the amount of the charge is changed successively from the face to the mouth, corresponding to the minimum distance between the inclined and vertical contour holes at the bottom of the lower bench is the minimum charge in the vertical contour hole, which in proportion with removal from the bottom of the lower bench successively increases, reaching its maximum value at the bottom of the intermediate bench, at the maximum distance between the inclined and vertical contour holes at the bottom of the lower bench the value of the charge in the vertical contour hole from the face to the mouth is changed in the reverse order.
EFFECT: enhanced efficiency of sloping.
7 dwg, 1 tbl
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