Borehole charge

Abstract

Borehole charge contains an explosive borehole in which the initiation means and explosive substance are placed up to the design level, as well as a casing above the explosive substance up to the level of the surface of the explosive block. In the cavity of the borehole, a sleeve made of an air-permeable sleeve made of polymer material is placed, the length of which exceeds the depth of the borehole, and the diameter is not less than the diameter of the borehole. Wherein the sleeve, isolated in the lower part, is provided with a weighting agent and is divided by a seam along the entire length into two containers - the main and auxiliary, which are filled with an emulsion explosive substance. Wherein the diameter of the auxiliary container does not exceed the diameter of the main container, and the free part of the sleeve is located above the explosive substance charge in the form of a gasket between the explosive substance and the casing made of crushed rock mass.

Description

The utility model belongs to the field of mining and blasting, namely to structures downhole charges of explosives used in drilling and blasting operations in in various mining conditions, including waterlogged and complex geological massifs. The technical solution can be used in open-pit mining of mineral deposits, in including in the extraction of ore and non-ore minerals. The utility model is expedient be used when forming charges in vertical and inclined blast wells of various diameter and depth in the presence of water inflow. The proposed design of the downhole charge is particularly effective in waterlogged conditions. wells, in the presence of fractures and caverns in the rocks, as well as if necessary ensuring stable charge geometry and maintaining calculated energy characteristics until the moment of initiation. The utility model can be applied when using emulsion explosives that require protection against water and mechanical factors. The closest analogue is a borehole charge, which includes an explosive borehole in which The initiation means and explosives are placed to the calculated level, as well as the deadlock above explosive to the level of the surface of the explosive block (V.F. Byzov, P.Y. Fedorenko "Explosives works". - Kryvyi Rih: "Mineral", 2021. - P. 130-133). The disadvantage of the known design of the borehole charge is that it is characterized by direct contact of the explosive with the water environment and the walls of the well, and also the lack of structural elements that provide insulation, structuring and mechanical charge stabilization. The main disadvantage of a close analogue is the hydrodynamic instability of the explosive column. substance under waterlogging conditions. When placing an emulsion explosive directly in the well cavity comes into contact with water, which can lead to partial erosion, filtration losses of components, changes in local density and disruption of the homogeneity of the structure along charge height. Under the action of the hydrostatic pressure of the water column and the explosive's own weight, it is possible stratification, formation of zones of reduced density, as well as the formation of internal cavities. This reduces the stability of the detonation process and worsens the predictability of the explosion parameters. In a watered well, if there is rock fracturing and water inflow, partial leakage or decompression of explosives in the bottom zone, leading to loss the calculated charging level and changes in energy distribution along the depth of the well. The absence sealing elements does not allow to ensure a stable position of the lower limit of the charge. The design of a close analogue also does not provide for structural separation of the explosive column. substance in cross section. The charge is formed as a single array, the diameter of which is determined exclusively well geometry. In case of uneven walls, presence of cavities or local expansions there is an uneven distribution of the mass of the explosive, which causes the appearance of zones of different density and worsens the contact of the charge with the rock mass. As a result, the efficiency decreases transfer of detonation energy to the environment. The lack of constructive means of forming charge zones of different diameters or volumes does not allows you to adjust the ratio of mass and density of the explosive within one cross-section. This limits the possibilities of optimizing the explosive effect depending on properties of the collapsing array. The purpose of the utility model is to create a borehole charge design that provides stable formation and preservation of the calculated geometry and density of the emulsion explosive column substances in the well, including in waterlogged conditions, with increased reliability, stability and predictability of explosion parameters. The utility model is aimed at solving the following interrelated technical problems: - ensuring the isolation of the emulsion explosive from the aqueous environment and filtration media processes in a waterlogged well; - increasing the hydromechanical stability of the explosive column due to its structuring in length and cross-section; - formation of a controlled distribution of the mass of explosives across the borehole cross-section with the possibility of creating main and auxiliary charge zones; - ensuring mechanical stabilization of the charge structure along the depth of the well and preventing its deformation during filling and placement of the toe; - maintaining the continuity and uniformity of the charge until the moment of initiation; - high-quality formation of an explosive charge in conditions of significant waterlogging of the well; - increasing the efficiency of detonation energy transfer to a rock mass due to ensuring tight and uniform contact of the charge with the well walls. The problem is solved by the fact that in a borehole charge containing explosive a well in which the initiation means and explosive are placed up to the design level, and also a blow above the explosive to the level of the surface of the explosive block, according to the useful model, a sleeve made of breathable polymer sleeve is placed in the well cavity material whose length exceeds the depth of the well and whose diameter is not less than the diameter wells, and the sleeve, insulated at the bottom, is provided with a weight and is divided with a seam along the entire length into two containers - the main and auxiliary, which are filled with emulsion explosive substance, while the diameter of the auxiliary container does not exceed the diameter of the main container, and the free part of the sleeve is located above the explosive charge in the form of a gasket between the explosive substance and a lump of crushed rock. The technical result achieved when using a borehole charge is: increasing the stability, reliability and reproducibility of charge parameters in waterlogged and complex mining geological conditions due to the isolation of the emulsion explosive, its structuring by cross-section and length of the well and mechanical stabilization of the structure. Using a sleeve made of breathable polymer material with an insulated bottom partly ensures the exclusion of direct contact of the emulsion explosive with water and rock massif, which prevents erosion, filtration losses and changes in charge density. In As a result, the calculated energy concentration is maintained throughout the height of the explosive column. The division of the sleeve by a longitudinal seam into the main and auxiliary capacity provides structuring charge across the cross section. This allows for a controlled distribution of mass and density explosive, reduces hydromechanical deformations during filling, reduces circumferential stress in shell and increases the stability of the column shape during charge formation. As a result of charge formation its stable geometry is ensured. The breathability of the sleeve material helps remove air from the inter-contact area between the charge and the walls of the well, which ensures a tight fit of the charge to the rock massif and increases efficiency of detonation energy transfer to the environment. This leads to more uniform destruction of the massif and a decrease in the proportion of undamaged areas. The presence of a free part of the sleeve, located above the charge and performing the function of a gasket, provides mechanical protection to the top of the explosive column during placement As a result, this prevents the charge from decompression, maintains its integrity and eliminates formation of rarefaction channels in the upper zone. Insulated lower sleeve and weighting ensure precise positioning depth charge and the stability of its lower limit, which increases the accuracy of compliance with the calculated charging level and improves the predictability of explosion parameters. The presence of the main and auxiliary tanks formed by a longitudinal seam, which made in a sleeve and due to the sequential regulated filling of the containers with explosive The substance ensures effective displacement of water from the well and the formation of a uniform charge bodies. The borehole charge is implemented in the following way. In a drilled water-filled blast well 1, made in a rock massif explosive block, previously cleaned of drilling cuttings and brought to the design depth, Place initiation means 2, in accordance with the blasting work passport. After installing the initiation means 2, a sleeve 3 made of air-permeable polymer material. Sleeve 3 has a length exceeding the depth of the well 1, and an outer diameter not less than the diameter of the well 1. The lower part of the sleeve 3 is insulated with a sealed bottom section 4, which prevents the escape of emulsion explosive and eliminates contact of the charge with the rock at the bottom of well 1. In the area of ​​the lower end of the sleeve 3, a weight 5 is installed, which ensures stable and directed immersion of sleeve 3 to the design mark and its straightening along the entire length of well 1. Sleeve 3 is divided along its entire length by a longitudinal seam 6 into two mutually insulated containers: main container 7 and auxiliary container 8. The longitudinal seam 6 is made continuous, hermetic and provides hydraulic and mechanical isolation of tanks 7 and 8 from each other along the entire length of sleeve 3. The diameter of the auxiliary tank 8 is not greater than the diameter of the main tank 7. This ratio diameters forms the required distribution of the mass of the explosive emulsion substance across the cross section of the well 1, ensuring preferential placement of the main volume of charge in the main container 7, additional localized placement in the auxiliary tank 8 and effective displacement of water from the well. After lowering sleeve 3, well 1 is sequentially filled to the design depth. emulsion explosive 9, the substance of the main container 7 and the auxiliary container 8. The filling is carried out to the calculated level, which corresponds to the design height of the charge in well 1. During the filling process, the emulsion explosive 9 is evenly distributed inside corresponding containers 7 and 8, while the longitudinal seam 6 prevents the redistribution of the substance between The breathable structure of the sleeve material 3 ensures the removal of excess air from the inter-wall space and promotes a tight fit of the filled containers 7 and 8 to the walls well 1, which increases the filling ratio and improves the contact of the charge with the rock mass. As a result, a borehole charge is formed, consisting of an emulsion explosive. 9, placed in the main container 7 and the auxiliary container of the sleeve 8 3, while the geometry of the transverse The charge cross section is determined by the ratio of the diameters of the specified capacities. Since the length of sleeve 3 exceeds the depth of well 1 after filling tanks 7 and 8 emulsion explosive 9 in the upper part of the well 1 remains free part sleeve 3, not filled with explosive. The specified free part of sleeve 3 is located directly above the formed charge and performs the function of a gasket 10. The free part of the sleeve 3 forms a separating layer between the surface of the charge and the subsequent coating. 11. Due to the air permeability of the material of the sleeve 3 and its flexibility, the free part is sealed under by the action of its own weight and the weight of the casing 11, forming a shock-absorbing and load-distributing gasket 10, which prevents the mechanical impact of the hammer directly on the emulsion explosive. After forming the gasket 10, a casing 11 is poured into the well 1 from the free part of the sleeve 3, made of crushed rock mass. The ramming 11 is placed above the free part of the sleeve of level 3 surface 12 of the explosive block. When the initiation means 2 is triggered, the detonation is transmitted to the emulsion explosive 9, placed in containers 7 and 8. The presence of two containers with different diameters ensures the formation of of the calculated charge structure of the well cross-section 1, and the longitudinal seam 6 provides effective feeding explosives into the sleeve. The insulated lower part 4 prevents the loss of emulsion explosive 9 in the lower zone well 1, and the weighting agent 5 ensures the accuracy of the charge positioning in depth. The free part of the sleeve 3, located between the charge 9 and the heel 11, helps stabilize the upper charge limits, reduces the likelihood of its decompression during backfilling and increases the resistance of the structure to the moment of the explosion. As a result, a well charge with controlled distribution of emulsion is realized. explosives according to the cross-section and height of the well, ensuring reliable insulation, stability of the charge geometry and the formation of an effective tip to the level of the explosive surface 12 block. The implementation of the device is based on the controlled formation of a column of emulsion explosive substances 9 in isolated containers 7 and 8 of hose 3 taking into account hydrostatic and contact-mechanical processes occurring in the well cavity 1. Emulsion explosive 9 is a viscoplastic medium with increased density. When the main tank 7 and the auxiliary tank 8 are sequentially filled, two parallel columns of matter, hydraulically isolated by a longitudinal seam 6. Due to the insulation of tanks 7 and 8: - transverse redistribution of mass under the action of hydrostatic pressure is excluded; - the asymmetric arrangement of the substance is eliminated during local deformations of the sleeve 3; - a stable charge structure is formed throughout the entire depth of well 1. The hydrostatic pressure in each container is determined by the height of the corresponding emulsion column. explosive 9. Since the diameter of the auxiliary container 8 does not exceed the diameter of the main container 7, the bulk of the substance is concentrated in the container 7, which ensures the formation of the central of an energetically saturated charge nucleus. The auxiliary capacity 8 performs the function of an additional energy distribution channel. Such distribution mass reduces the possibility of internal ruptures of the BP column under the influence of its own weight, since each capacity perceives the load autonomously. The air permeability of the polymer material of the sleeve 3 ensures effective displacement of water from inter-wall space between the outer surface of the containers 7, 8 and the walls of the well 1 in the process filling. If water is not removed, local layers form in the intercontact zone, which reduce the actual area of ​​contact of the charge with the walls of the well 1 and create zones of reduced impedance. The structure of the sleeve 3 ensures the gradual displacement of water outwards as the internal pressure increases in containers 7 and 8 during filling with emulsion explosive 9. As a result, the outer surface of the filled containers 7 and 8 is evenly pressed against the walls. well 1, the charge contact coefficient with the rock massif increases, it is excluded formation of breaks in the continuity of the BP column. Hydrodynamically, this leads to the formation of a stable column of matter without cavities and internal rarefaction, which is especially important with a significant depth of the well 1. The longitudinal seam 6 performs not only the function of a hermetic separation, but also the role of a longitudinal rib. When filling containers 7 and 8, under the action of hydrostatic pressure, radial expansion occurs expansion of the sleeve walls 3. Due to the division into two containers, the effective radius of each cavity decreases, reducing the magnitude of the circumferential stress in the material of the sleeve 3 increases the stability of the cross-sectional shape. Thus, the design works as a system of two parallel cylindrical shells of smaller diameter instead of one large shell, which reduces the likelihood of local material ruptures. Even with local damage to one tank, the geometry of the second tank is preserved, which increases operational reliability of the charge. The insulated lower part 4 takes the total axial load from the explosive columns emulsion substance 9. The tightness of the lower section prevents the substance from filtering into the pore space rock space, which eliminates the reduction of charge density. The weighting agent 5 forms a directed axial force when lowering the sleeve 3 into the well 1. Due to This eliminates the folding of the sleeve and ensures its straightening along the axis of the well, A uniform distribution of containers 7 and 8 along the entire depth is achieved. Mechanically, the weighting device 5 creates a pre-tension of the sleeve 3, which increases the stability of the position. longitudinal seam 6 and prevents twisting of the containers relative to the well axis. The free part of the sleeve 3, located above the charge, functions as an intermediate layer-gasket 10 between emulsion explosive 9 and slug 11. Additionally, gasket 10 reduces the possibility of formation of decompression zones in the upper part of the charge under dynamic impact during backfilling. The set of features is an insulated lower part 4, a longitudinal seam 6, a division into containers 7 and 8, the air permeability of the sleeve 3 material ensures the stability of the BP column geometry throughout its depth; absence of internal cavities and air inclusions; uniform distribution of charge density; ensuring the calculated parameters of the well charge before its initiation. When the initiation means 2 is triggered, the detonation wave propagates in the medium with uniform density and continuous structure, providing predictable parameters explosive impact on a mass of rocks. Thus, the hydrodynamic separation of the flows of emulsion explosive 9 in tanks 7 and 8 in combined with mechanical stabilization of the sleeve design 3 ensures the formation of a stable, geometrically controlled and energetically uniform borehole charge placed in well 1 to the level of the wellbore 11.

Claims

A borehole charge containing an explosive borehole in which the means are placed initiation and explosive to the calculated level, as well as a blowout above the explosive substance to the surface level of the explosive block, which is distinguished by the fact that in the cavity a sleeve made of breathable polymer material is placed in the well, the length of which exceeds the depth of the well, and the diameter is not less than the diameter of the well, and the sleeve, insulated at the bottom, is provided with a weight and is separated by a seam along the entire length into two containers - the main and auxiliary, which are filled with emulsion explosive substance, while the diameter of the auxiliary container does not exceed the diameter of the main container, and the free part of the sleeve is located above the explosive charge in the form of a gasket between the explosive and the crushed rock mass.

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