Method of blast ore breaking off mass of laminated texture (versions)

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

 

The invention relates to the mining industry, and in particular to methods blasting ore from the array with a layered texture, for example, in the development of ferruginous quartzite open way.

There is a method of blasting ore in open pits, which includes the drilling of parallel rows of vertical wells, the loading wells charges explosives (he) followed by stemming, installation of explosive network and short-delay blasting charges [1].

The disadvantage of this method is that the loss of strength of the structural relations of the ore is carried out by increasing the specific consumption of EXPLOSIVES.

There is a method of blasting ore from the array with a layered texture, which includes the drilling of parallel rows of vertical wells at an angle β to line stretch layers, loading boreholes with explosive substances and their subsequent stemming and blasting in each row with the formation of the inclined shock wave compression [2]. This method is adopted us as a prototype.

The disadvantage of this method is that it does not provide effective softening ore array with a layered texture, because the orientation of the inclined plane of the front of the blast wave compression does not take into account the location of the layers of the array.

The objective of the invention is to increase the efficiency of the softening ore with ASD the freight mineral grains by creating maximum shear stresses in the planes of the layers of the array at an arbitrary angle them fall by the orientation of the inclined plane of the front of the blast wave compression under optimal angle to the line of strike of the layers.

In the first embodiment it is achieved that the way blasting ore from the array with a layered texture, which includes the drilling of parallel rows of vertical wells at an angle β to line stretch layers, loading boreholes with explosive substances and their subsequent stemming and blasting in each row with the formation of the inclined shock wave compression, while blasting hole charges in the range of angle β determine from the relation:

where α - the angle of incidence of layers;

γ - the angle between the plane of the front of the blast wave compression and vertical.

According to the second variant it is achieved that the way blasting ore from the array with a layered texture, which includes the drilling of parallel rows of vertical wells at an angle β to line stretch layers, loading boreholes with explosive substances and their subsequent stemming and blasting in each row with the formation of the inclined shock wave compression, under the sequential blasting hole charges in each row, determine the angle β from the expression:

where α - the angle of incidence of layers;

γ - the angle between the plane of the front of the blast wave compression and vertical;

Ψ - the rotation angle of the plane of the front of the blast wave is compression around the vertical axis relative to the line stretch layers, which is defined as:

where υpanel- the speed of propagation of elastic waves in the array;

t is the time interval between the explosions of the charges in the first and last wells range;

L is the length of a given number of wells, and two characters angle Ψ choose the one in which the angle between the line of each row of wells and line the edge of the ledge closer to the 90° or equal to 90°.

Figure 1 and 2 presents the scheme of the mutual arrangement of the planes of the surface of the ledge, layers of the array, the wave front compression scheme and rows of wells on the ledge while blasting charges in each row.

Fig 3 and 4 shows the scheme of the mutual arrangement of the planes of the surface of the ledge, layers of the array, the wave front compression scheme and rows of wells on the ledge under the sequential blasting hole charges in each row.

Figure 5 and 6 shows the schematic of the formation of the inclined plane of the front of the blast wave, respectively, when the simultaneous and the sequential blasting hole charges in each row.

The way blasting ore from the array with a layered texture has two options. The method according to the first embodiment is as follows.

On the horizontal surface of the shelf 1 ore array with a layered texture is determined by the geological documentation or visually line 2 Prostir the Oia arranged in parallel layers 3 and the angle α the fall of these layers. This is followed by a line 4 rows of blastholes 5 angle β to line stretch layers defined by a relationwhere γ - the angle between the plane of the front of the blast wave compression and vertical while blasting hole charges in the row (see figure 1 and 2). The rest of the rows of wells on a ledge carried out parallel to this row 4 (see figure 2). Next, make the drilling and loading of EXPLOSIVES followed by stemming. When this action is placed in the lower part of the charge, for example, at the foot of the escarpment. After mounting the blast network and switching charges in each row to produce their blasting. When blasting one borehole charge is formed by the blast wave front in the form of a truncated cone 6, the radii of the bases of which are increasing in time, and when the blasting of a number of borehole charges is formed, the resulting front of the blast wave from this number in the form of a plane 7, the angled γ the vertical (see figure 5). The angle γ depends on the velocity of propagation of elastic blast in the array (υpaneland detonation of EXPLOSIVES in a borehole (υdewand equal. In the first embodiment while blasting charges in each row, the inclined surfaces 7 of the front of the blast compression wave generated from the ka is Dogo number of wells, parallel lines 4 rows of wells (Fig, 1 and 5 shows one of these planes and the line of their intersection with the surface of the ledge coincide with the lines 4 of the shattered ranks. The maximum softening ore array with a layered texture is reached by orienting the plane of the front of the blast wave compression in the plane of the layers at an angle of 45°which, in the plane of the plies, the maximum shear stress. At the location of the rows of wells at an angle β to line stretch layers according to the formula (1), the angle between the planes of the wave front and compression layers 45°and, therefore, provide maximum alloys intergranular links in ore array of shear stresses.

The method according to the second variant is as follows.

On the horizontal surface of the shelf 1 ore array with a layered texture is determined by the geological documentation or visually line 2 stretch parallel spaced layers 3 and the angle α decline in these layers. This is followed by a line 4 rows of blastholes 5 angle β to the line of strike of the strata, defined by equation (2)where γ - the angle between the plane of the front of the blast wave compression and vertical, Ψ - the rotation angle of the plane of the front of the blast wave compression around the vertical is C relative to the line stretch layers (see 3). The rst term in the formula (2) represents the angle β' relative to the line 2 stretch that defines the line 8 (see figure 3 and 4). The rest of the rows of wells on a ledge carried out parallel to this row 4 (see figure 4). Next, make the drilling and loading of EXPLOSIVES followed by stemming. When this action is placed in the lower part of the charge, for example, at the foot of the escarpment. After mounting the blast network and switching charges in each row to produce their blasting. When blasting one borehole charge is formed by the blast wave front in the form of a truncated cone 6, the radii of the bases of which are increasing in time, and when the blasting of a number of borehole charges is formed, the resulting front of the blast wave from this number in the form of a plane 7, the angled γ to the vertical. The angle γ depends on the velocity of propagation of elastic blast in the array (υpaneland detonation of EXPLOSIVES in a borehole (υdewand equal(see Fig.6).

Under the sequential blasting hole charges in each row for maximum softening intergranular links in ore array is also necessary to Orient the plane of the front of the blast wave compression relative to the planes of the layers at an angle of 45°. Unlike the first option, the radius r of the upper base to the practical front compression wave for time t from the explosion of the first to blast the last wells of a number of increases to the amount equal to r=υpanel·t, where υpanel- speed, explosive propagation of elastic waves in the array. The result is a rotation around the vertical axis inclined to the plane of the wave front compression relative to the line stretch layers on the cornerwhere L is the length of a given number of wells. Two characters angle ψ choose the one in which the angle ϑ between the center line of each row of wells and line the edge of the ledge is closer or equal to 90° (see figure 4). At the location of the rows of wells at an angle β to line stretch layers according to the formula (2) is the angle between the planes of the wave front and compression layers 45°and, therefore, provide maximum alloys intergranular links in ore array of shear stresses. In practice, lines 4 rows of wells oriented relative to the line 9 of the edge of the ledge. Since line 2 stretch layers of the array is specified by the geological documentation angle θ to line 9 of the edge of the ledge, the series 4 wells placed at an angle of ϑ to line 9 of the edge of the ledge, equal ϑ=180°-θ-β (see figure 2 and 4).

Thus, this method provides maximum softening mineral grains in the planes of the layers of the array.

Examples of implementation described method.

Example 1.

On career Stoilensky GOK angle Paden what I layers is 30° , speed υpaneland υdewthe explosive spread of the elastic wave in the array and detonation of EXPLOSIVES in a borehole, respectively, equal to 4.9 km/s and 7 km/s (for TNT). As CENTURIES accepted the TNT. At the bottom of the borehole at the level of the foot of the escarpment set Thriller. Line stretch layers of ferruginous quartzite relative to the edge of the ledge is the angle θ=45°.

In this case the angle between the plane of the front of the blast wave compression and vertical equal.

While blasting charges in each row, the angle between the line 2 stretch layers and rows of 4 wells are determined according to the formula (1),. As a result, the rows of wells placed at an angle of ϑ=180°-45°-73°=52° the line of the edge of the ledge (see figure 2).

Under the sequential blasting holes in a row, we assume that the wells in the row are connected only detonating cord without pyrotechnic moderators (CSDS). Then the correction for the angle ψ rotate the plane of the front of the blast wave compression around the vertical axis relative to the line of strike of the layers is determined by the expression:

where υdeedsthe propagation velocity of the detonation wave in LH, 6.5 km/s Hence we have

Accept the mark m is the Nusa for amendments ψ on the nonsimultaneity of explosives and have the angle between the line stretch layers and line numbers of wells equal to:

The rows of wells placed at an angle of ϑ=180°-45°-23°=112° the line of the edge of the ledge (see figure 4). If you choose to amendments ψ plus, we have β=73°+50°=123° and ϑ=180°-45°-123°=12°i.e. the angle ϑ between the rows of wells and line the edge of the ledge to a greater extent different from the 90°than with a minus sign.

Example 2.

As CENTURIES also accept the TNT. The angle of incidence of the layers is equal to α=45°. Line stretch layers of ferruginous quartzite relative to the edge of the ledge is the angle θ=45°. In this case the angle between the plane of the front of the blast wave compression and vertical is also equal to

.

While blasting wells corner β between line 2 stretch layers and rows of 4 wells is equal to:

.

The rows of wells placed at an angle of ϑ=180°-45°-65°=75° the line of the edge of the ledge.

Under the sequential blasting holes in this example also accept a minus sign for amendments ψ on the nonsimultaneity of the blasting hole charges in range and angle β between line 2 stretch layers and rows of 4 wells will be:

The rows of wells placed at an angle of ϑ=180°-45°-15°-=120° the line of the edge of the ledge. If you choose to amendments ψ plus, we have β=65°+50°=115° and ϑ=180°-45°-115°=20°i.e. the angle ϑ between the rows of wells and line the edge of the ledge to a greater extent different from the 90°than with a minus sign.

Example 3.

As CENTURIES also accept the TNT. The angle of incidence of the layers is equal to α=75° and line them stretch is the angle θ=45° line 9-edge of the ledge. In this case the angle between the plane of the front of the blast wave compression and vertical is also equal to

.

While blasting angle β between line 2 stretch layers and rows of 4 wells should be equal to:

.

The rows of wells placed at an angle of ϑ=180°-45°-41°=94° the line of the edge of the ledge.

Under the sequential blasting holes in this example, accept the plus sign for amendments ψ nonsimultaneity of blasting holes in a row and then the angle β between line 2 stretch layers and rows of 4 wells will be:

The rows of wells placed at an angle of ϑ=180°-45°-91°=44° the line of the edge of the ledge. If you choose to amendments ψ the minus sign, we have β=41°-50°=-9° and looking to anicely to 45° the angle between the lines stretch and the edge of the ledge, i.e. 180°-45°=135° find ϑ=180°-135°-9°=36°i.e. the angle ϑ between the rows of wells and line the edge of the ledge to a greater extent different from the 90°than when choosing a plus sign.

The proposed method allows to use the energy of explosion when blasting in open pits for directional softening intergranular links ore arrays with a layered texture at all angles of incidence layers and any orientation of the line of their spreading on the surface of the ledge. Using this technique significantly improves the performance of subsequent processing (crushing and grinding) of ore.

Sources of information

1. Kutuzov BN. The destruction of rocks by explosion (explosive technologies in the industry). M.: Publishing house of Moscow state mining University, 1994, p.148, 4.3.

2. RF patent №2055303 in class. F 42 D 3/04, E 21 37/00, 41/26, 1996 (prototype).

1. The way blasting ore from the array with a layered texture, which includes the drilling of parallel rows of vertical wells at an angle β to line stretch layers, loading boreholes with explosive substances and their subsequent stemming and blasting in each row with the formation of the inclined shock wave compression, characterized in that while the blasting hole charges in the row Hugo is β determine the ratio

where α - the angle of incidence of layers;

γ - the angle between the plane of the front of the blast wave compression and vertical.

2. The way blasting ore from the array with a layered texture, which includes the drilling of parallel rows of vertical wells at an angle β to line stretch layers, loading boreholes with explosive substances and their subsequent stemming and blasting in each row with the formation of the inclined shock wave compression, characterized in that under the sequential blasting hole charges in each row, determine the angle β from the expression

where α - the angle of incidence of layers;

γ - the angle between the plane of the front of the blast wave compression and vertical;

ψ - the rotation angle of the plane of the front of the blast wave compression around the vertical axis relative to the line of strike of the layers, which is defined as

where υpanel- the speed of propagation of elastic waves in the array;

t is the time interval between the explosions of the charges in the first and last wells range;

L is the length of a given number of wells

with two characters angle ψ choose the one in which the angle between the line of each row of wells and line the edge of the ledge closer to the 90° or equal to 90°.



 

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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

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