RU2506533C1 - Suspension well stemming - Google Patents

Abstract

FIELD: blasting operations.

SUBSTANCE: invention refers to mining, to drilling and blasting operations in mine rocks and can be used in different fields applying blasting operations in mine rock masses, and namely at open development of useful minerals. A suspension well stem is made from a piece of material that is bound with two ropes on the outer side; one end of the first rope is bound with a stiff knot, thus forming the first internal volume, inside which a support is arranged. A transverse support size is by 30-50% less than the well diameter. The other end of the first rope is passed inside through the centre of the material piece and attached to a crossbar at the well head. The second rope is bound with a free knot above the stiff knot, with possibility of its movement along the first rope, thus forming the second internal volume, the transverse diameter of which is by 15-20% larger than the well diameter and one third of which is filled with loose inert material; ends of the material piece are left free.

EFFECT: invention allows reducing specific explosive flow, improving crushing quality of mine rock due to long-term arrangement of detonation products in a charging cavity till complete destruction of mine rock, simplifying the structure and improving structure actuation reliability.

2 dwg

Description

The invention relates to mining, to the field of drilling and blasting in rocks and can be used in various industries that use blasting in massifs of rocks, in particular in open pit mining.

Known borehole stemming from rock fines, etc., which increase the duration of expanding gaseous products of an explosion on a destructible massif (Kutuzov BN Blasting operations. M: Nedra, 1988, p.223).

Also known is a borehole stemming having the shape of a cylinder, the external diameter of which is comparable with the diameter of the well (RF patent No. 2229684, IPC 7 F42D 1/20, publ. 05.27.2004). A disadvantage of the well-known bottomhole is the complexity of manufacture and installation, the unreliability of the operation of the structure.

Known suspension borehole shutter (RF Patent No. 2319924, IPC F42D 1/20, published March 20, 2008), adopted for the prototype, which is made of a piece of material and placed inside a piece of cargo material fixed inside a piece of material with a rope, a piece of material outside is tied free a knot with another rope around the first, and the transverse size of the shutter is less than the diameter of the well.

However, the known shutter is designed to disperse the charge in the well.

The technical result, the solution of which the present invention is directed, is to reduce the specific consumption of explosives, improve the quality of crushing of the rock due to the long-term locking of the detonation products in the charging cavity until the complete destruction of the surrounding rock, simplification of the design, improving the reliability of the structure.

The specified technical result is achieved by the fact that the suspended borehole stemming is made of a piece of material that is tied with two ropes from the outside, one end of the first rope is tied with a rigid knot, forming the first internal volume inside which the support is placed, its transverse size is 30-50% less than the diameter of the well and the second end of the first rope is stretched inward through the center of the piece of material and attached to the crossbar at the wellhead, the second rope is tied with a free knot above the rigid knot, with the possibility of its movement along rvoy rope, forming a second inner volume, the transverse diameter of which is 15-20% more than the borehole diameter, and a third full of particulate inert material, the ends of the segment material is left free.

The inventive suspended borehole stemming is illustrated by drawings, where in Fig.1 shows the design of the suspended borehole stemming, in Fig.2 - suspended borehole stemming in the working position.

The inventive suspended borehole stemming is made of a piece of material (for example, an explosive bag) tied with two ropes from the outside. One end of the first rope 1 is tied with a rigid knot 2, forming the first internal volume 3, inside which the support 4 is placed, the transverse size of the support is 30-50% less than the diameter of the well (for example, a large piece of rock of appropriate size). The size of the support is empirically selected and depends on the diameter of the drilling, which is determined by the strength of the blasted rocks, the type of explosive used and the rational degree of explosive crushing. The second end 5 of the first rope 1 is stretched inward through the center of the piece of material and is attached to the crossbar 6 at the wellhead, with which the suspended well stall is fixed at the required depth.

The second rope 7 is tied with a free knot 8 above the rigid knot 2 in such a way that it can move the free knot along the second end 5 of the first rope 1, forming a second internal volume 9, the transverse dimension of which is 15-20% larger than the diameter of the well. The second internal volume 9 is filled by a third with a loose inert material 10, and the ends of the material segment are left free in order to uniformly fill the cross section of the well, avoiding spillage of drill trifle.

When analyzing the results of a series of industrial explosions conducted in order to assess the effectiveness of the claimed invention in the explosive preparation of strong and very strong rocks, strength 10-18 on the scale of prof. M.Protodyakonova was found that it is optimal to use the declared diameter for placing in the lower part of the bottom hole of a support (piece of rock). This is due to the fact that during an explosion the support 4, under the influence of expanding explosion products, penetrates into a space filled with loose inert material, but does not act as a piston pushing inert material from the well, but, on the contrary, because its size is smaller than the diameter the set value of the well, contributes to an additional compaction of drill trifle and the development of stress centers along the interface of the “drill trifle-rock in its entirety” interface, which is the well forming, leading to a significant increase in the sliding friction forces of the suspended borehole stemming on the borehole wall and, accordingly, an improvement in the blocking effect.

The inventive suspended borehole stemming works as follows. After drilling the block, the wells are charged, the detonating chain is mounted, then into the well to the depth of the massif with intense fracturing (secondary fracturing, formed from the impact of the previous explosion - 1.5-2.5 meters) on a rope, which is fixed on the crossbar located at the mouth wells, lower the borehole stemming. Inert material is poured from above (for example, a bayonet or small rock) to the day surface.

Under the influence of the weight of loose inert material located inside the second volume and supported from below by a support located in the first volume, the suspended borehole stem is flattened, blocking the borehole and fits snugly against the borehole walls.

Under the weight of the drill trifle, the knot formed by the second rope slides along the first rope, the suspended well stump is evenly flattened, and the free ends of a piece of material tightly cover the gap between the suspended well stall and the walls of the well, preventing spillage of drill trifle.

At the time of the explosion, the support (a large piece of rock) is embedded in a loose inert material 10 with which the second internal volume is filled, as well as in an inert material (drill trifle) 11 that fills the space between the bottom hole and the wellhead; compacts the above-mentioned rock formations, increasing the friction force of the stem from the wall of the well, directed opposite to the upward movement of the elements of the stem, and thereby locking the explosion products in the explosive chamber.

The presence in the suspended borehole stemming of a piece of material partially filled with loose inert material 10 is determined by the need to install the borehole stemming in a certain part of the well - at a depth of intense fracturing, i.e. the depth at which the rock mass is not affected by the destructive effects of the previous explosion. In other words, the second internal volume 9 with inert material 10 when installed in the well due to the free node 8 in its upper part is placed in such a way that evenly fills the cross section of the well

The inventive suspended borehole stemming allows the maximum use of the energy of the explosion products, to intensify the process of crushing rocks, to reduce the specific consumption of explosives, to improve the quality of crushing of rock mass.

At the same time, the following is achieved: ensuring the operating time of the suspended borehole stemming, necessary for the maximum use of the energy of the gaseous products of the explosion; simplification of placement of suspended borehole stemming inside the well; simplicity of production of suspended borehole stemming; a significant reduction in the cost of the product due to material savings, improving the reliability of the operation of the stemming.

Claims (1)

Suspended borehole stemming, characterized in that it is made of a piece of material that is tied with two ropes from the outside, one end of the first rope is tied with a rigid knot, forming the first internal volume inside which the support is placed, its transverse dimension is 30-50% less than the diameter of the well, and the second end of the first rope is stretched inward through the center of the piece of material and attached to the crossbar at the wellhead, the second rope is tied with a free knot above the rigid knot, with the possibility of its movement along the first rope, forming the second internal volume, the transverse diameter of which is 15-20% greater than the diameter of the well and is filled by a third of loose inert material, while the ends of the piece of material are left free.

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