Vol 148 No 1
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Date submitted2000-06-27
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Date accepted2000-07-04
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Date published2001-01-01
Modern physical and technical problems of rock fracture (based on research supported by the Russian Foundation for Basic Research and the work of leading institutions in Russia and several CIS countries)
- Authors:
- K. N. Trubetskoi
- S. D. Viktorov
The problem of rock fracture is one of the most important scientific problems in the modern system of mining sciences. The efficiency of rock destruction determines the efficiency of all subsequent stages of mining production. We offer an overview of modern scientific research on rock fracture, carried out in Russia and some other CIS countries.
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Date submitted2000-06-08
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Date accepted2000-07-12
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Date published2001-01-01
Modern problems concerning destruction of rock during well drilling
- Authors:
- Vladimir S. Litvinenko
- B. B. Kudryashov
Born in ancient times, drilling wells until the second half of the 19th century remained mostly percussive on rope or rods. Rotary drilling was only manual and was used for sinking shallow wells in weakly cohesive rocks. As far back as 600 years B.C. Confucius wrote of thousands of wells as deep as 500 m and even as deep as 1,200 m drilled in China for water and salt. Over the centuries this ancient invention of the Chinese has hardly changed. French travelers of the 19th century described Chinese drilling technology as it was more than 2.5 thousand years ago.
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Date submitted2000-06-17
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Date accepted2000-07-19
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Date published2001-01-01
Disruptive effect of an explosion in a pre-stressed environment
- Authors:
- V. V. Adushkin
- A. A. Spivak
Despite ongoing attempts to create new destruction technologies based on non-traditional approaches to mining (thermal destruction, exposure to radiation streams and high energy particles, etc.) the explosion of chemical explosives remains the main way of crushing rocks in the massif. It seems that in the coming decades, explosive technology will remain dominant on an industrial scale.
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Date submitted2000-06-02
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Date accepted2000-07-28
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Date published2001-01-01
Current state of the theory of detonation and methods of predicting parameters of condensed explosives
- Authors:
- K. K. Shvedov
The phenomenon of detonation underlies numerous technologies for the beneficial use of explosive explosive energy (EE). The history of its discovery and study goes back more than a hundred years, but many aspects remain unclear.
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Date submitted2000-06-18
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Date accepted2000-07-21
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Date published2001-01-01
State, prospects and expert evaluation of the optimal size of the possible use of industrial explosives in Russia
The basis for the work presented is the Resolution of the Interdepartmental Council on Explosives № 3 dated 10.12.99. A number of leading specialists of the country in the field of development, production and use of explosives (explosives) were involved in the preparation of materials.
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Date submitted2000-06-21
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Date accepted2000-07-22
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Date published2001-01-01
Experimental studies of the destructive effect of explosion in a solid medium when changing the properties of explosives
- Authors:
- E. I. Efremov
- V. A. Nikiforova
- A. V. Ponomarev
As is known, the mining of non-metallic minerals has special requirements for blasting operations, as the lumpiness of the blasted rock mass is limited not only by the maximum, but also by the minimum size of the lump. In determining the rational degree of crushing, for example, fluxing limestone and dolomite, along with the output of oversized fractions, it is necessary to consider the volume of over-crushed rock mass (fractions with particle size less than 5 mm), negatively affecting the yield of commercial products. In this case the second factor is often more significant, because in nonmetallic pits the yield of over-crushed rock mass reaches 20%, which not only leads to losses of commercial products, but also reduces the efficiency of the explosion (the huge cost of explosion energy for rock crushing). In this regard, studies of the influence of explosive properties of explosives on the yield of regrind product, taking into account the compliance of explosive properties with the nature of the destructed medium, are very important in terms of both energy consumption and resource saving (losses of minerals).
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Date submitted2000-06-24
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Date accepted2000-07-17
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Date published2001-01-01
Blasting technology in the quarry of the Maidanpek mining enterprise
- Authors:
- I. Krsmanovich
Studies of geological and structural features of the massif structure have shown that in andesites with depth there are diagonal type faults, which break the ore zone into blocks. The width of the faults is up to 1 m, and in some cases even more. Presence of faults essentially influences the process of drilling and quality of rock blasting. Diagonal faults have a steep drop and jibs and fractures have a gentle drop. The gentle dip of cracks has a strong influence on the conditions of propagation of explosive waves, which must be taken into account in the design of blasting operations.
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Date submitted2000-06-27
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Date accepted2000-07-18
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Date published2001-01-01
Use of bulk emulsion explosive to improve blast and production performance at Jingduicheng оpen pit
- Authors:
- Xiong Daiyu
- Qin Hu
- Ren Xiaoming
- Wang Xuguang
At mid-1980s, many large and middle open pits in China began to equip bulk emulsion explosive trucks, and progressively realized site manufacturing and mechanical charging of mining explosives, which, to a great extent, increased the blast and mining production efficiency, and promoted Chinese mining blast technical progress. The site manufacturing and charging technology for bulk emulsion explosives may considerably simplify components and preparation process of mining explosives, realize mechanization of explosive preparation and charging blast hole, improve safety during manufacturing, transportation and handling of explosives ...
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Date submitted2000-06-30
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Date accepted2000-07-11
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Date published2001-01-01
Numerical simulation of a blast effect in a soft formation
- Authors:
- V. G. Bazhenov
- V. L. Kotov
- A. V. Kochetkov
At present, there is a significant number of experimental and theoretical works devoted to the study of the properties of soft soils under explosive loading and experimental methods for determining the shock adiabats of soft soils. However, the results obtained are largely contradictory, and both further research into the basic properties of soft soils and an in-depth theoretical justification of the experimental methods themselves are required. This paper presents the results of a numerical study of the impact of a superimposed explosive charge on sandy soil through a metal impactor plate. The ground is modeled by S.S. Grigoryan’s compressible medium with irreversible volumetric and shear deformations. Numerical solutions obtained using various shock adiabats known in the scientific literature are compared with experimental data. As a result, a synthesized sand shock adiabat is proposed and justified in the range from low pressures up to 1 GPa. The influence of volumetric plastic deformations and friction forces on wave processes in the ground is analyzed.
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Date submitted2000-06-10
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Date accepted2000-07-27
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Date published2001-01-01
Formation and registration of solitons in granular media
In the world around us there are many examples of environments composed of the same elements. These include biological structures, electrical circuits, and granular artificial materials. Similar structures composed of separate granules and blocks can be found in a rock formation. All these media have nonlinear properties and are extended. We are interested in the method of energy transfer through media of periodic structure.
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Date submitted2000-06-18
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Date accepted2000-07-12
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Date published2001-01-01
Solitons and structured media diagnostics
Real rocks are characterized by a diverse heterogeneity of structure, so the problem of determining the properties of such media is no less urgent than the problem of their fracture
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Date submitted2000-06-01
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Date accepted2000-07-08
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Date published2001-01-01
Prediction of stress wave parameters in kimberlites based on the model of layered isotropic elastic media
The problem of resource saving when mining diamond-bearing kimberlites at the Udacha open pit of ZAO Udachinsky GOK is extremely relevant, since in the last decade there has been a stable tendency of reducing the quality of commercial products - diamond crystalline raw materials. Examination of the character of damages of diamond monocrystals suggests that the technological defects of crystals are caused, first of all, by the pulse mode of loading crystals of host rocks at the stages of explosive destruction, mechanical crushing and grinding of kimberlite ore at the crushing and milling equipment. This is evidenced by the nature of damage to diamond single crystals manifested in crushing, shear and chipping cracks. The highest damageability occurs in medium and large diamonds, especially of the +2 class. In its turn, according to the CCA, taking into account the cost of diamonds of different size and quality groups, 1% increase in preservation allows to get an additional profit of about $7 million. ALROSA's efforts are aimed at improving the natural preservation of rough diamonds, which is why research has been resumed to predict the parameters of stress waves that are potentially dangerous in terms of damage to the rough diamonds. Since kimberlites are breccia and tuff-like rocks with rather homogeneous properties in layers with different elevations, which tend to increase acoustic stiffness with depth of occurrence, they can be considered as layered homogeneous isotropic elastic media.
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Date submitted2000-06-09
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Date accepted2000-07-06
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Date published2001-01-01
Vibratory equipment for disintegration of technogenic and mineral raw materials
The most common and energy-consuming technological processes in industry and agriculture are crushing and grinding. It is known that they absorb about 20% of the electricity generated on the planet. Such high energy consumption is due to the fact that modern crushing and milling machines use the processes of destruction mastered in ancient times: compression, impact, abrasion, cutting. In this case the material is destroyed haphazardly, almost without using microcracks and other defects of its structure, which causes extremely low efficiency of crushing and milling units. In addition, the use of these effects on the material leads to irreversible loss of useful components or to a significant deterioration in the properties of the products produced from them due to the incomplete disclosure of the useful component or, conversely, overgrinding, pelletizing or damage to the particles.
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Date submitted2000-06-12
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Date accepted2000-07-02
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Date published2001-01-01
Development of a fractured coal structure under the action of high pressure
The study of the impact of high pressure on the structure and behavior of coals is not only of practical interest, but also of academic interest, because it contributes to the accumulation of information necessary for the most complete understanding of the processes occurring here. Experimental results show that tectonic stresses during metamorphism reach values sufficient for molecular regularization, which leads to an increase in the degree of graphitization of coals.
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Date submitted2000-06-02
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Date accepted2000-07-24
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Date published2001-01-01
On numerical simulation of stationary and non-stationary processes in fractured rocks
The problems of numerical modeling of the behavior of fractured (non-cohesive) continuous media are related to the development of mining technologies (mainly, explosions on discharge), the study of landslide processes, as well as the phenomena established in seismically hazardous zones. The energy of deformation of unbound media is spent on overcoming internal friction and loosening. The description of irreversible deformations in non-cohesive media on the basis of physical models with constants included in them is possible if these constants are determined in laboratory or field experiments. In laboratory tests of specimens, it is not always possible to establish these constants directly, therefore, it is necessary to carry out additional calculations simulating test conditions.
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Date submitted2000-06-02
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Date accepted2000-07-22
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Date published2001-01-01
Prediction of disruptive action of stress waves on the basis of seismological data
- Authors:
- I. V. Vorontsov
- V. G. Shemenev
Designing mine workings, mining, construction of underground facilities for various purposes at great depths and in difficult mining and geological conditions is closely related to the task of determining the stress-strain state (DS) of rock massifs.
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Date submitted2000-06-06
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Date accepted2000-07-07
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Date published2001-01-01
On a numerical algorithm for solving nonlinear problems in geomechanics
Designing of mine workings, mining, construction of underground structures of various purposes at great depths and in difficult mining and geological conditions is closely connected with the task of defining the stress-strain state (SSS) of rock massifs.
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Date submitted2000-06-22
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Date accepted2000-07-30
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Date published2001-01-01
Assessment of rock fracturing using the index of irregular cleavage
- Authors:
- K. A. Dolgov
The result of an explosion in fractured rock depends on its degree of fracturing, which can be characterized by the fractional composition of lump sizes in the massif. Fractured massifs are usually classified into very large-block, large-block, medium-block and small-block. In order to predict the sustainable results of the mining, it is necessary to know the category of fracturing of the massif.
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Date submitted2000-06-03
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Date accepted2000-07-07
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Date published2001-01-01
On the delaminability of unstrengthened heavy coal seam roofs
- Authors:
- N. F. Dontsul
- G. N. Zhurov
In the literature, the impact of unstrengthening on the stratification of rocks of heavy roofs has not been given enough attention. As is known, the delamination of layered rocks of the roof of workings significantly reduces their bending stiffness, which eventually leads to a significant increase in the normal to the layering displacements of layers between the layers and the formation of limiting zones. In this regard, prediction of the stratification of unstrengthened in combination with hydraulic treatment of rocks of heavy roofs is important, as it is used in selecting the optimal parameters of coal deposits development systems, providing the necessary operational mode of the working chamber, as well as in solving other important geomechanical problems.
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Date submitted2000-06-06
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Date accepted2000-07-04
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Date published2001-01-01
On the stratification of anisotropic interbedded rocks
- Authors:
- N. F. Dontsul
- G. N. Zhurov
- P. K. Tulin
In this paper, the method developed by Professor S.T. Kuznetsov for calculating the delamination of sedimentary roof rocks with close elastic characteristics is proposed to be transferred to transversal-isotropic interlayered rocks. The issue of predicting possible patterns of delamination and detachment of interbedded rocks with elastic anisotropy is very important, since the obtained information is used in selecting and properly placing high-capacity complexes and mechanized supports, as well as in solving other important problems of mining geomechanics.
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Date submitted2000-06-22
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Date accepted2000-07-29
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Date published2001-01-01
On the effect of humidity on the stratification of interbedded rocks
Based on the use of the special limit state condition, studies were conducted on the effect of moisture on the stratification of layered interbedded rocks for the case of overworked and then underworked interbedded rocks. The researchers paid insufficient attention to the effect of humidity on the stratification of interbedded rocks. As is known, the stratification of stratified rocks of the roof of mine workings significantly reduces their bending stiffness, which eventually leads to a significant increase in normal to the layering displacements of interlayered layers and the formation of limit zones. In this regard, prediction of the stratification of interbedded rock, with account of moisture, is important, as it is used in selecting the optimal parameters of the passports of mine workings, providing the necessary operational mode of mine workings, as well as in solving other important geomechanical problems.
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Date submitted2000-06-01
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Date accepted2000-07-11
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Date published2001-01-01
Calculation of the stress state of rock mass during vertical concentrated charge explosion
- Authors:
- A. A. Eremenko
- V. M. Seryakov
- G. P. Ermak
Among the methods of rock destruction used in the development of mineral deposits, the drilling and blasting method is the most widely used. A significant number of works are devoted to practical and experimental study of rock mass destruction processes, in which a comprehensive assessment of the problem in question is carried out. At the same time, practice constantly puts forward new tasks, the solution of which is difficult to implement on the basis of available knowledge and ideas. It is impossible to overcome the emerging difficulties without additional scientific research. A large number of issues requiring a solution arise in the fields of Mountain Shoriya and Khakassia when applying vertical concentrated charges (VCC). They are used for destruction of technological blocks of rocks formed during the mining of ore bodies by the systems of stage forced collapse. The main purpose of successful application of VCC is the maximum destruction of the ore massif within the excavated block.
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Date submitted2000-06-27
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Date accepted2000-07-28
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Date published2001-01-01
On approaches to determining blast efficiency in geotechnology
As is known, the external indicators of the development of mineral deposits (geology, requirements for the final technological indicators, etc.) are constantly becoming more complex. At the same time, in the modern mining practice the most important role is played by the processes of destruction as the basis of mining, and the main means at the head of all geotechnologies of solid minerals extraction is the explosive energy. It has a price and its intrinsic controllability.
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Date submitted2000-06-12
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Date accepted2000-07-15
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Date published2001-01-01
Characteristics of explosive fracturing of overburden permafrost rocks
Most of Yakutia's open-pit coal deposits are characterized by favorable mining and geological conditions: horizontal bedding, relatively small thickness of overlying rocks, location of deposits close to populated areas, high quality of coals, etc. However, mining operations are significantly complicated by the harsh climate and the permafrost condition of the rock massif.
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Date submitted2000-06-11
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Date accepted2000-07-21
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Date published2001-01-01
Second stage of wave-free expansion of the cavity of a concentrated explosive charge
- Authors:
- N. N. Kazakov
In the technical literature, it is widely accepted that crushing of rock during explosion is carried out by stress waves, that only 1-5% of the energy of stress waves is spent on crushing. When exploding an explosive charge in a rock, the nature of energy transfer to the external environment depends on the properties of the explosive, charge density, the geometry of the charge and its position in the massif.
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Date submitted2000-06-17
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Date accepted2000-07-01
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Date published2001-01-01
Regularities of formation of zones of fine and radial cracking in the destruction of rocks by explosion of elongated charges
- Authors:
- G. M. Kryukov
- I. V. Smager
- I. I. Drozd
A large number of scientific, research, experimental and experimental-industrial works both in Russia (USSR) and abroad are devoted to the processes of destruction of rocks by explosion. As a result of these works, the basic laws of deformation and destruction of rocks by explosion have been established. Nevertheless, when solving specific practical problems in specific mining and technical conditions it is necessary to carry out additional research and experimental work, allowing with a given efficiency and reliability to conduct drilling and blasting operations. This is due, firstly, to the complexity of the structure and, accordingly, the wide variability of properties of objects deformed and destroyed by explosion; secondly, mining-technical and technological features of blasting and, thirdly, the imperfection of developed models of explosive impact on deformable and destructible environment.
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Date submitted2000-06-23
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Date accepted2000-07-02
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Date published2001-01-01
Stress concentration and scale factor in the fracture of anisotropic rock
- Authors:
- Yu. M. Lebedkin
- A. S. Matorin
- V. G. Shemenev
Fracture of rocks for industrial or other needs (hammering, drilling, extraction of piece rock, processing, etc.) regardless of the method and technology of loading is a local short-term intensive impact, proceeding according to the scheme: load application - deformation - growth of micro- and then macro-damages - growth of cracks - fracture. In this regard, the applied theory of rock failure should not take into account rheology and relaxation, i.e., the model of such failure does not take into account the evolution of micro- and macro-damages in the rock. These phenomena can be accounted for by the ultimate stress or strain in the current state of the fractured rock volume.
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Date submitted2000-06-30
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Date accepted2000-07-05
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Date published2001-01-01
Method for calculation of additional rock fracture at the quasi-static stage of blasting action
To calculate the parameters of drilling and blasting operations for explosive destruction of rocks, empirical dependences or relations based only on the action of stress waves are used. It is known, however, that at the quasi-static stage of the explosion there is additional destruction of rocks. It is manifested both in the secondary crushing of pieces in the fracture zone and in the increase in the size of this zone. Qualitatively, these effects are known and used, in particular, in the creation of various types of faces in the mouths of boreholes and wells, increasing the duration of the quasi-static stage of the explosion. However, the physical and mechanical processes of additional fracture at the quasi-static stage of the explosion have been studied much less than at the wave stage.
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Date submitted2000-06-24
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Date accepted2000-07-20
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Date published2001-01-01
Relaxation in soils and rocks
- Authors:
- A. V. Mikhalyuk
The physical basis of most known methods of explosion control is the dependence of mechanical behavior of rocks (deformation, fracture) on the time characteristics of the loading mode. However, using this dependence, we usually do not take into account its relaxation nature, which is characteristic of the entire class of geophysical media, actively affecting changes in their physical state, determining the dissipation of energy of force impact and, consequently, affecting its result. Therefore, the study of the relaxation properties of rocks has been given increased attention.
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Date submitted2000-06-28
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Date accepted2000-07-26
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Date published2001-01-01
Estimation of microcracking in coal during methane desorption
- Authors:
- V. N. Odintsev
At present, when a number of industrial regions producing coal are experiencing a shortage of gas fuel, the problem of industrial production of methane at coal deposits is urgent. To solve it, it is necessary to investigate a number of fundamental scientific problems. One of the main tasks is to establish the patterns of decay of the natural system "coal - methane" and the migration of methane to mining wells. According to the views prevailing among many experts, almost all of the methane is in the coal in the absorbed (dissolved) state, and the coal bed is initially gas-tight. Therefore, not in all cases, drilled wells can give methane in the required volume. This is evidenced by field experiments. Some gas production wells produce little methane. Other wells, such as those in the coal fields of the San Juan Basin, have very high gas yields.
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Date submitted2000-06-09
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Date accepted2000-07-06
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Date published2001-01-01
Specific energy consumption at different levels of rock fracturing
- Authors:
- B. R. Rakishev
- M. S. Kushpanov
It is known that in technological processes of drilling, blasting, crushing and milling, depending on the conditions and nature of the application of the external load, different amounts of energy are spent on the destruction of a unit volume of rocks. The analysis shows that each of the widespread empirical laws of crushing is a part of a more general law of crushing, obtained by the authors of the article on the basis of the universal energy criterion of destruction taking into account the scale effect.
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Date submitted2000-06-20
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Date accepted2000-07-13
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Date published2001-01-01
On some characteristics of a plastic wave
- Authors:
- E. S. Tkachenko
To successfully combat such gas-dynamic phenomena as sudden releases of coal (rock) and gas or rock bumps, it is necessary to have a clear understanding of the mechanism of destruction of a solid body. To study such a phenomenon in mines is rather labor-intensive for known reasons, but to achieve effective results in this area it is necessary to know more deeply at least the simplest mechanism of destruction of coal (rock) samples during their compression in the press, because the nature of the destruction of samples and massif are the same. Previously, on the basis of experiments on testing coal specimens on the press the fact of specimen destruction by plastic waves was established and the experimental method of determining the velocity of plastic waves V fl during the destruction of specimens was proposed. The authors propose the hypothesis of pulsation of an elastic-plastic wave during its propagation and the generation of a running plastic wave.
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Date submitted2000-06-13
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Date accepted2000-07-15
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Date published2001-01-01
Dynamics of stochastic instability and fractal nature of fractures
- Authors:
- K. V. Khalkechev
For a long time, the development of our ideas about the fracture process was hampered by the incomplete mathematical description of the conditions near the crack end. In recent years, this subject has attracted considerable research attention, which has led to some important results. However, these theories are also unable to describe the crack growth pattern with sufficient completeness. In this paper, attention is focused on the investigation of equilibrium and non-equilibrium crack propagation conditions at a given location and the prediction of the pattern of its further propagation, as well as on the mechanical and mathematical substantiation of the fractality of the fracture surface.
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Date submitted2000-06-04
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Date accepted2000-07-05
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Date published2001-01-01
Fracture widening characteristics at blasting mining of granite in far zone
- Authors:
- V. A. Shekov
- O. V. Myasnikova
- M. G. Menzhulin
Explosive block blasting is one of the key operations in the technology of extraction of granite blocks in the production of natural stone facing materials. It provides both acceptable economic expenses at extraction of blocks, and the corresponding productivity of the extracting enterprise. The main requirement for such operations is to minimize the impact of blasting on cracking in the granite block.
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Date submitted2000-06-11
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Date accepted2000-07-13
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Date published2001-01-01
On the working efficiency of mixtures of ammonium nitrate and aluminum in blasting
- Authors:
- A. N. Afanasenkov
- B. N. Kukib
The use of aluminum in mixture compositions is explained by the fact that its oxidation releases a large amount of energy, which should increase the detonation (velocity, pressure) and explosive (brilliance, throwing ability, workability) characteristics of the composition. However, numerous experiments have shown that this is not the case. For example, the introduction of up to 20% A1 in the composition does lead to an increase, although to a lesser extent than expected, of the heat of explosion Q (as measured in a calorimeter bomb) and of the blast effect, which is the greater the larger the particles of A1. The detonation velocity of powerful explosives with the introduction of A1 decreases, and the effect is the stronger the smaller the size of its particles. The brisance of mixtures practically does not change, the critical diameter of detonation increases, etc.
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Date submitted2000-06-12
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Date accepted2000-07-16
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Date published2001-01-01
Mechanized method for the preparation of granulite-Zh and the results of its pilot tests
Explosive blasting of dry granite massifs in the quarries of the Leningrad region is currently carried out with standard explosives: ammonite and grammonite 79/21 (82/18). Explosive blasting of watered massifs is carried out with 30/70 and 50/50 grammonite, granulotole and conercial explosives of granipor type. The experience of our foreign northern neighbors has shown that under similar conditions safer and cheaper ANFO-type non-trinitrotoluene compositions and other water-emulsion explosives can be successfully used. Switching to these explosives allows to refuse the expensive transportation of dangerous cargoes over long distances, as they can be prepared on site. The first experience of application of locally prepared no-trinitrotoluene explosives has been carried out at several granite pits of Vyborgsky District of the Leningrad Region and Kamennogorsk. As the simplest explosive the granulite-Zh developed by the authors was used (patent No.2088559 with the priority of invention of 1992). Granulite-G is an explosive composition with the averaged chemical formula C 4.0-5.0 H 8.0-9.0 N 0.04-0.08 O with the following proportions of components by weight, %: ammonium nitrate - 80-95; fatty protein additive - 5-20.
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Date submitted2000-06-27
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Date accepted2000-07-12
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Date published2001-01-01
Application of industrial explosives produced by ORICA in mining enterprises
ORICA products are widely known in the global market of industrial explosives consumers. Currently, the company has plants in 30 countries of the world, which produce various types of granular (ANFO) and emulsion (POWERGEL) explosives, as well as non-electric EXEL blasting systems. In May 1999, a group of specialists in the field of blasting from the Republic of Kazakhstan left for Turkey to conduct acceptance tests of industrial explosives of ORICA company, which are widely used in Kazakhstan since 1995 in underground and surface mining of mineral resources, blasting with boreholes and wells in weak, medium- hard and tough rocks, in dry and water-filled boreholes and wells. The annual consumption of explosives is about 10,000 tons.
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Date submitted2000-06-09
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Date accepted2000-07-12
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Date published2001-01-01
Modification of aquatol compositions considering their demixing
- Authors:
- A. A. Vakhotin
- S. D. Viktorov
- N. G. Demchenko
Long-term practice of using aquatrinitrotoluenes for blasting shows that the main drawbacks of these compositions: tendency to delamination and relatively low water resistance, have not yet been overcome. The delamination of aquatrinitrotoluene components during formation of charges in real conditions leads to reduction of specific heat of explosive transformation of the whole charge on average up to 30 % (tab.1). Currently, emulsion explosives, which do not have these drawbacks, are more widely spread in the practice of blasting works
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Date submitted2000-06-21
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Date accepted2000-07-22
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Date published2001-01-01
Assessment of actual energy detonating aquatrinitrotoluene characteristics in long relieving blast charges considering the stability of the physical composition
- Authors:
- M. G. Gorbonos
- V. I. Sivenkov
- V. I. Pochekutov
One of the main problems of effective use of water-containing explosives (WCE) in various mining and geological conditions and especially when blasting waterlogged massifs is the stability of aquatrinitrotoluene charges. When mixing a hot oxidizer solution (HOS) in mixing and charging machines with granulated or flaked TNT, the latter, having the density of granules p = 1,48+1,5 g/cm3, cannot be kept suspended in the explosive mixture, since the density of HOS does not exceed 1,4 g/cm3. As a consequence, there is a stratification of water-filled explosives, which leads to a change in the energy and detonation characteristics of explosives, to a deterioration of bottom penetration, to an increase in the yield of oversized material.
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Date submitted2000-06-21
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Date accepted2000-07-13
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Date published2001-01-01
Technological opportunities to improve properties of blended explosives based on experience in Mongolia and Yugoslavia (Serbia)
It is known that the explosive characteristics and explosive efficiency of mixed explosive compositions determine not only the chemical composition and ratio of the components, but also their physical state and the uniformity of mutual distribution (mixing). The most famous example is mixtures of ammonium nitrate and TNT: grammonite 79/21 and ammonite 6ZV, which are identical in chemical composition, but differ significantly in dispersion of the components, the critical diameter, velocity, detonation pressure, etc. Here it should be noted that in determining the homogeneity of a heterogeneous system, it is necessary to consider both the size and homogeneity of mixing of the condensed components of the composition and the size and homogeneity of distribution of possible, and sometimes necessary, gas inclusions, which is typical, for example, for bulk mixtures based on porous ammonium nitrate (AN) granules and water-bearing explosives in the form of emulsions and (or) suspensions.
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Date submitted2000-06-09
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Date accepted2000-07-30
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Date published2001-01-01
Laser initiation of energy-intensive compositions
The interest in works devoted to laser impact on energy-saturated compositions (EC) has been steadily increasing recently, which is largely predetermined by the practical needs of creating safe means of initiation of explosives. Conducting research on experimental selection of optimal chemical compositions of ES that meet the requirements of their remote detonation and formation of profiled detonation waves during laser initiation with a given sequence of actuation is quite in demand.
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Date submitted2000-06-14
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Date accepted2000-07-20
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Date published2001-01-01
Energy performance of oversized lumps crushing with the use of standard and conversion blasting equipment
In the practice of rock excavation by borehole and borehole charges, oversized lumps of rock mass are formed, the yield of which is caused by: the physical and mechanical properties of rocks, the blockiness of rock masses, the parameters of drilling and blasting operations and other factors. The presence of oversized lumps of rocks on working platforms of open pits complicates technological processes of excavation and transport, reduces the efficiency of loading and transporting equipment. In underground mining the crushing of oversized lumps of rock mass is carried out on scraper tracks, in ducts and ore stacks, during the works in which the most difficult are the cases of jamming and vaulting.
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Date submitted2000-06-13
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Date accepted2000-07-11
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Date published2001-01-01
Use of recycled ammunition explosives to produce conversion explosives directly in the disassembly process
At present, the bases and arsenals of the RF Ministry of Defense contain a considerable quantity of conventional ammunition (CA) with an expired shelf life. The total quantity of high explosives contained in them is estimated at about 100 million tonnes. Certainly, this value is not comparable with the annual consumption of industrial explosives in Russia (1 million tons). However, if we take into account the potential man-made danger, as well as the absolute material value of chemical raw materials, their introduction into the economic turnover is an important environmental and economic task.
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Date submitted2000-06-30
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Date accepted2000-07-27
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Date published2001-01-01
Optimization of types of explosives for open-pit mining in Muruntau
- Authors:
- O. N. Malgin
- V. N. Sytenkov
- S. K. Rubtsov
The general direction of development of mining works in the Muruntau open pit is to increase its development depth to 700 m and more with the expansion of the area of application of cyclic-flow technological schemes of development with the use of steep-slope conveyors, which significantly tightens the requirements to the size of the transported material. In view of this, the main concept of improving the technology of blasting in the quarry is the intensification of blasting processes and increasing the specific weight of the blasting method of crushing as the cheapest and most technologically advanced.
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Date submitted2000-06-02
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Date accepted2000-07-04
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Date published2001-01-01
On the use of aluminized high explosive compositions in industrial slurry explosives
- Authors:
- I. A. Ovyan
Despite the widespread work on the disposal of ammunition, the problem of both the discharge of ammunition filled with powerful aluminized explosives, and the use of extracted explosives in the extractive industries remains relevant. In the present work some questions of the use of aluminized explosives of the composition type: hexogen, phlegmatizing agent - aluminum powder, as the main component for the production of industrial explosives are considered.
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Date submitted2000-06-09
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Date accepted2000-07-26
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Date published2001-01-01
Experience of using emulsion explosive slarrit in open-pit mining operations of Pechenganickel OAO Kola MMC using the technology of Dino Nobel, a Norwegian company
- Authors:
- V. F. Ogienko
Prior to 1999, rock mass was stripped in the open-pit operations at the Tsentralny mine with domestic standard explosives. Granulotol was used on watered blocks, while 79/21 grammonite was used on "dry" blocks. Igdanite was used in insignificant quantities due to the lack of sufficient mechanization and its low energy for rocks with a hardness factor of 14-18 (according to Protodiakonov). Detonating cord DShE-12 and TNT-400G were used as means of initiation. In this technology there was practically no mechanization. All operations, from unloading of wagons to loading of boreholes were performed manually, transportation was carried out by KrAZ-256B trucks. As a whole, this complex of works was excessively costly. This state of affairs could not satisfy the company management.
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Date submitted2000-06-06
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Date accepted2000-07-27
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Date published2001-01-01
Analysis of explosive characteristics of water-containing explosives with reduced TNT content
- Authors:
- D. S. Podozerskii
- S. A. Edigarev
- E. A. Vlasova
The study of the mechanism of excitation and propagation of detonation processes in water-containing explosives (WCE) has important scientific and practical significance. The stability and completeness of detonation of explosive charges determine the amount of energy released and the explosion momentum, which predetermine all subsequent phases of explosion development, namely: deformation of rock, its crushing, movement of rock mass and seismic action.
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Date submitted2000-06-05
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Date accepted2000-07-28
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Date published2001-01-01
On some fundamentals of the effectiveness of explosive destruction of rocks
- Authors:
- V. I. Pugachev
At the 2nd International Scientific Conference "Physical Problems of Rock Fracture" it is appropriate to note the great role of scientists from the St. Petersburg Mining Institute (A.N. Khanukaev, V.N. Borovikov, etc.) in studies of wave parameters of explosive loading of rocks. The successes achieved in the study of blast waves substantiated the expectation that "the development of engineering methods of explosion energy control should be based mainly on the management of these wave parameters" (V.N.Mosinets, 1976). However, the mechanism of rock deformations and fractures could not be unambiguously substantiated by the parameters of explosion waves. Wave theory gave a good idea of the primary effect of the explosion, in acoustic approximation allowed to approach the solution of many problems, but did not find application to determine the main parameters of charges in the practice of blasting.
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Date submitted2000-06-05
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Date accepted2000-07-26
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Date published2001-01-01
Explosion energy control during core charge excitation by shockwave action
- Authors:
- B. U. Raskildinov
One of the ways to improve the efficiency of drilling and blasting operations is to improve the design of borehole and borehole column-mounted charges during explosive blasting of solid minerals. The analysis of existing designs of explosive charges, used for stripping the rock mass at mining enterprises, allows to note that along with the widespread solid cylindrical column of explosives, quite a large number of more effective designs, allowing to actively manage the energy of the explosion in the destruction of the rock massif, has been developed. These designs are based on the extensive use of a number of factors: reducing the initial pressure of the explosion products, increasing the time of their impact on the massif, creating several groups of detonation waves in the charge, cumulation, etc. However, despite the advantage of dispersed charges compared with solid charges, they have not yet found wide application due to the significant material and time costs of charging boreholes or wells.
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Date submitted2000-06-10
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Date accepted2000-07-19
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Date published2001-01-01
Ways of expanding the range of industrial explosives and methods of controlling their energy characteristics
- Authors:
- I. A. Ryzhukhin
- A. A. Ivanov
To regulate the impact of explosion in the directional destruction of rocks, it is necessary to use industrial explosives (IE) with a sufficiently wide range of energy, technological and physical-mechanical properties. In some cases, it is even necessary to reduce the volumetric energy density and create controlled systems for energy transfer and extraction. When developing the explosives for the mining industry it should be taken into account that the efficiency of the use of explosives is determined not only by the degree of useful use of the potential energy of the charge, but also by the possibility to control the mechanism of destruction of rocks. The creation of methods of controlling the explosion energy is based on a qualitative change in the mechanism of its action by introducing additives to the PVB composition, improving the technology of preparation, modifying the surface of the energy-intensive metal combustibles.
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Date submitted2000-06-05
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Date accepted2000-07-15
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Date published2001-01-01
Methods of charging explosive wells with aquatrinitrotoluene
During the testing and industrial development of the process of charging wells with aquatools, a number of problems affecting the quality of explosive preparation of rock mass arose.
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Date submitted2000-06-23
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Date accepted2000-07-16
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Date published2001-01-01
Inorganic explosives for safe means of priming charges in oil wells
Constantly tightening requirements for explosives (explosives) in terms of safety in handling, reliability, environmental friendliness, etc. have led to a search for explosives for safe means of initiation that meet these requirements among complex compounds. Among coordinated compounds, pentaammonates of cobalt (III), containing substituted tetrazoles as the sixth ligand and the perchlorate anion as the external ion, stand out by their physicochemical characteristics.