scholarly journals REGULARITIES OF CHANGES IN THE GAS-DYNAMIC AND GEOMECHANICAL SITUATION AT POTASH MINES

2021 ◽  
Vol 13 (3) ◽  
pp. 426-432
Author(s):  
Alexander ZEMSKOV ◽  
◽  
Maria LISKOVA ◽  
Guzel SHARIPZYANOVA ◽  
◽  
...  

Mining operations in potash and salt deposits are complicated by gas emissions and gas dynamic phenomena. The analysis of a large number of gas dynamic phenomena and intense gas emissions at potash mines in Russia and Belarus allowed the authors to identify some patterns. In particular, it was found that the maximum number of gas dynamic phenomena occurs in the 7–10 year of operation of the mines. The purpose of the study is to analyze and identify available information on the influence of heliophysical and manmade factors on the state of rock massifs, which will allow purposefully predicting and preventing the manifestations of these factors, increasing labor safety and efficiency of mining enterprises. Research methods: methods of a full-scale mine experiment to determine the gas content of rocks and the gas content of workings, as well as analysis of statistical data. The results of the study showed that the analysis of data on 84 cases of gas dynamic phenomena at the mines of PJSC Uralkali revealed an increase in the volume of gas emissions from the developed lavas spaces at the mines of JSC Belaruskali as a result of a drop in barometric pressure on the surface. In conclusion, it can be noted that the combination of natural factors together with a powerful man-made impact on the environment creates certain prerequisites for disasters of various scales, ranging from destructive earthquakes to subsidence of mountain pressure, gas dynamic phenomena and intense gas emissions in mines and mines. The set of established patterns formed the basis for the development of a number of preventive measures that increase the safe working conditions of miners and the efficiency of mining enterprises.

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 5205
Author(s):  
Martina-Inmaculada Álvarez-Fernández ◽  
María-Belén Prendes-Gero ◽  
Juan-Carlos Peñas-Espinosa ◽  
Celestino González-Nicieza

In the last decades, rigorous research has been carried out with the end of understanding the gas dynamic phenomenon and although different preventive techniques have been employed, even today there are numerous accidents even with the loss of life. This work analyses an alternative and innovative method of fracturing and degassing coal, by generating CO2 with a pyrotechnic device called PYROC (Pyrotechnic Break Cartridges). Medium-scale tests of generation of CO2 into coal samples are carried out and their effect is analysed comparing the initial and final permeabilities of the coal samples once the generation of CO2 has finished. These permeabilities are calculated by injecting methane. Besides, the influence of different parameters as the length of the boreholes, the pressure of the gas or the initial permeability of the coal have been analysed with a numerical simulation of one face of one of the sublevels of a mine. The results show that the method increases the safety in mining operations because it fractures and degasses the coal, increases the permeability of the coal in the borehole of injection from 9.5 mD to 31 mD, decreases the methane gas pressure below pre-detonation levels for 1 min, achieves decompressed lengths between 8 and 10 m ahead of the face with pressures of injection of 50 MPa, relaxes the total length of the borehole for initial coal permeability values equal to or greater than 0.002 mD, and allows to work with low permeable coals with high induced stresses and high methane concentrations.


2020 ◽  
pp. 234-243
Author(s):  
S.I. Skipochka ◽  
◽  
T.A. Palamarchuk ◽  
L.V. Prokhorets ◽  
V.P. Kurinnyi ◽  
...  

When studying risk factors in coal mines, it is necessary, in the first place, to consider factors and properties of the rock massif occurred with the deepening of mining operations in the coal mines, and determine one of the main types of danger: risk of geodynamic phenomena. The geodynamic phenomena occur and develop under the influence of natural and technological factors. Natural factors determine the rock massif proneness of ato geodynamic manifestations or, in other words, its potential danger due to these phenomena. Occurrence of this danger depends on technological factors. Among the dangerous factors of underground coal production to which primarily belong the geodynamic phenomena, the main ones are gas-dynamic phenomena, which are the most complex by their nature and dangerous by consequences due to high dynamic power and release of great amount of gas during a short period of time. Their consequences can be accidents due to sudden gassing and blockage of workings by coal and rock, explosions of methane and coal dust, destruction of the roadway supports, damage of machines and mechanisms, equipment and devices. As the gas-dynamic phenomena in the rocks massif are accompanied by occurrence of various processes differed by their nature, therefore, risks caused by them should be taken into account at mining operations. When considering the gas-dynamic phenomena attention should be paid to the shock wave propagation, as it is one of the gas dynamic processes. Therefore, purpose of this research was to study specific features of the shock wave propagation in the rock massif in order to prevent dangerous consequences. In this article, the authors consider the processes which occur in the rock massif prone to dangerous gas-dynamic phenomena at the shock wave propagation. The methods of rock mechanics, mechanics of continuous media, gas and thermodynamics were used in the research. Analytical researches of processes and numerical analysis of the received results were carried out. It is shown that a sharp increase of thermodynamic parameters under the action of gas-dynamic phenomena can lead to occurrence of the shock waves. It is further established that an explosive air-methane mixture can be formed in cracks, cavities and pores of the face area. At opening the cavities and pores, cases of shock waves formation in air-methane mixture leading to its detonation are possible. Under adverse conditions, this phenomenon can lead to a fire in the roadway.


Author(s):  
P. A. Vityaz ◽  
I. I. Golovaty ◽  
V. Ya. Prushak

Gas-dynamic danger of Krasnoslobodsky fracture zone in Starobin Deposit of potassium salts was investigated. The study was carried out taking into account the existing ideas about the mechanism of formation of foci of gas-dynamic phenomena in the salt rock mass of the field, as well as taking into account the results of seismic and hydrogeological studies of the fault zone and the revealed patterns of distribution of gas-dynamic phenomena over the field area. The features of the geological structure of Krasnoslobodsky fracture zone in the upper salt stratum containing layers of potash ore are established. The features of the mechanism of evolution of hydrodynamic systems in fault zones are revealed. It was found that the functional system of halogen metasomatosis in these zones of the rock mass was not shielded, so that the absorption zone of the hydrodynamic system was located in the rocks of the clay-marl strata located above the upper salt strata and horizons of possible mining operations, and fractured rocks of the fault zone provided gas filtration from the system of voids formed during the evolution of hydrodynamic systems. According to the results of the study, it was concluded that in Krasnoslobodsky fracture zone within the upper salt layer there were no conditions for the formation of dangerous foci of gas-dynamic phenomena, such as sudden emissions of salt and gas and collapse of roof rocks. Accordingly, there is a possibility of safe mining operations, such as the penetration of intersecting workings through the fault zone.


2018 ◽  
Vol 11 ◽  
pp. 46-55
Author(s):  
E.V. Ulyanova ◽  
◽  
V.A. Vasilkovskiy ◽  
O.N. Malinnikova ◽  
◽  
...  

2003 ◽  
Vol 14 (1) ◽  
pp. 59-67
Author(s):  
Adepo Jepson Olumide ◽  
Ayodele Charles Oludare ◽  
Balogun Olufemi

Coal, a solid fuel in its natural state has been identified as one of the world's major fossil fuels. It is a compact, stratified mass of mummified plant debris interspersed with smaller amounts of inorganic matter buried in sedimentary rocks. The use of coal as an energy source can be dated back to the prehistoric times. Methane is associated with many if not all coal seams, and is the dreaded “fire damp” responsible for many pit explosions. Coal mines are designed to vent as much methane as possible. It is present in the pores of coal under pressure, released during mining operations and can be extracted through vertical well bores. This paper highlights the fact that pipeline- quality methane can be extracted economically from coal seems before and during underground mining operations. The stimulation method involves hydraulic fracturing of the coal seam by using water, sand and, a gelling agent in a staged and alternating sand/and no sand sequence. The purpose is to create new fractures in the coal seam(s). The cleating of the coal helps to determine the flow characteristics of the coal formation and is vital in the initial productivity of a coal-methane well. The simple calculation of gas-in-place is achieved by multiplying the gas content of the coal by net coal thickness, the density, and the aerial extent of the drainage. The method is claimed to be suitable for use in Nigeria and potential sites for coal bed methane extraction in Nigeria are identified.


2021 ◽  
pp. 76-80
Author(s):  
A. A. Vyunikov ◽  
◽  
S. G. Vorozhtsov ◽  
N. V. Khoyutanova ◽  
E. K. Pul ◽  
...  

Starting from 2019 extraction of diamond ore reserves from Internatsionalnaya pipe by Internatsionalny mine of ALROSA is carried out in complex geological and geomechanical conditions. Geodynamic situation is complicated by a few gas dynamic phenomena of different nature and scale recorded. The investigation results on gas release dynamics from dolomite rock mass during drivage of Spiral decline, in a test site on level.-802/-820 m in case of prediction and prevention measures undertaken to combat gas dynamic phenomena are presented. The dynamic characteristics of gas in outburst-hazardous dolomite rocks are calculated by the initial velocity of gas release. Efficiency of the current outburst hazard prediction method using facility MIG-Ts1 is proved. At the same time, it is necessary to perform additional studies to collect sufficient statistics and reliable data on gas release and gas pressure during drivage operations in the mine. The authors appreciate participation of Deputy CEO of VostNII Science Center, Doctor of Engineering Sciences, Professor V. S. Zykov, Doctor of Engineering Sciences, Professor A. V. Dzhigrin, Director of Research Center for Applied Geomechanics and Convergent Technologies in Mining at NUST MISIS College of Mining, Doctor of Engineering Sciences, Professor of the Russian Academy of Sciences V. A. Eremenko and Director of VNIMI’s Kemerovo Division, Candidate of Engineering Sciences P. V. Grechishkin.


2011 ◽  
Vol 56 (8) ◽  
pp. 423-426 ◽  
Author(s):  
I. A. Znamenskaya ◽  
I. E. Ivanov ◽  
E. Yu. Koroteeva ◽  
D. M. Orlov

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