Integrated estimation of strength properties of complex-structure coal seams

2019 ◽  
Vol 8 ◽  
pp. 33-41 ◽  
Author(s):  
Yu.N. Linnik ◽  
◽  
V.Yu Linnik ◽  
A.B. Zhabin ◽  
A.V. Polyakov ◽  
...  
Keyword(s):  
Complex Structure ◽  
Strength Properties ◽  
Coal Seams ◽  
Integrated Estimation

scholarly journals Criteria for the difficulty of working out coal-bearing zones of quarry fields

2019 ◽  
Vol 134 ◽  
pp. 01018
Author(s):  
Alexei Selyukov ◽  
Nuray Demirel
Keyword(s):  
Complex Structure ◽  
Uneven Distribution ◽  
Open Pit ◽  
Coal Seams ◽  
Mining Methods ◽  
Coal Reserves ◽  
Working Out

Coal-bearing zones of open pit fields are represented by formations of coal seams from inclined to steep bedding with unstable thickness, both in dip and strike with different dip angles even within the same strata, with varying rock inter-layers and strength. In addition, most coal seams have a complex structure, including rock layers inside. In most cases, there is an uneven distribution of coal seams, and, consequently, coal reserves over the area of quarry fields. In this regard, for the analysis of quarry fields, there is a need to select criteria for assessing the complexity of coal-bearing zones for the purpose of systematizing them and choosing directions for constructing technological schemes for excavation and loading operations and mining methods.

scholarly journals Maintenance of reusable mine workings during the augering mining of coal seams

2018 ◽  
Vol 60 ◽  
pp. 00001
Author(s):  
Volodymyr Bondarenko ◽  
Hennadii Symanovych ◽  
Iryna Kovalevska ◽  
Viktor Chervatiuk
Keyword(s):  
Strength Properties ◽  
Geometric Parameters ◽  
Cement Stone ◽  
Regression Equations ◽  
Variable Rigidity ◽  
Coal Seams ◽  
Stress Strain ◽  
Extraction Working ◽  
Mine Workings ◽  
The Stability

The augering mining of thin and very thin coal seams has been proposed for using the efficiency of this task, related to the stability of reusable mine workings. The interrelation has been established and optimized between the support loading parameters in the extraction working during the augering mining of thin and very thin coal seams with the stress-strain characteristics of the protective monolithic strip of variable rigidity. The strength properties of sand-cement stone for the erection of rigid and yieldable parts of the protective strip are studied. The regression equations are obtained, which allow to determine the rational force, deformation and geometric parameters of the “support – protective strip” system elements during the extraction workings maintenance.

scholarly journals Coupling Technology of Deep-Hole Presplitting Blasting and Hydraulic Fracturing Enhance Permeability Technology in Low-Permeability and Gas Outburst Coal Seam: A Case Study in the No. 8 Mine of Pingdingshan, China

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Wei Wang ◽  
Yanzhao Wei ◽  
Minggong Guo ◽  
Yanzhi Li
Keyword(s):  
Coal Seam ◽  
Hydraulic Fracturing ◽  
Complex Structure ◽  
Coal And Gas Outburst ◽  
Gas Content ◽  
Low Permeability ◽  
Gas Extraction ◽  
Deep Hole ◽  
Coal Seams ◽  
Gas Outburst

The current study aims to analyze the principles of integrated technology of explosion to tackle the problems of coal seam high gas content and pressure, developed faults, complex structure, low coal seam permeability, and high outburst risk. Based on this, we found through numerical simulation that as the inclination of the coal seam increases, the risk of coal and gas outburst increases during the tunneling process. Therefore, it is necessary to take measures to reduce the risk of coal and gas outburst. We conducted field engineering experiments. Our results show that the synergistic antireflection technology of hydraulic fracturing and deep-hole presplitting blasting has a significant antireflection effect in low-permeability coal seams. After implementing this technology, the distribution of coal moisture content was relatively uniform and improved the influence range of direction and tendency. Following 52 days of extraction, the average extraction concentration was 2.9 times that of the coal seam gas extraction concentration under the original technology. The average scalar volume of single hole gas extraction was increased by 7.7 times. Through field tests, the purpose of pressure relief and permeability enhancement in low-permeability coal seams was achieved. Moreover, the effect of gas drainage and treatment in low-permeability coal seams was improved, and the applicability, effectiveness, and safety of underground hydraulic fracturing and antireflection technology in low-permeability coal seams were verified. The new technique is promising for preventing and controlling gas hazards in the future.

scholarly journals Evaluation of Synthesized Catalytic Complex Structure-Forming Ability during Paraffin Base Tar Upgrade

2018 ◽  
Vol 7 (4.36) ◽  
pp. 1006
Author(s):  
Alim F. Kemalov ◽  
Ruslan A. Kemalov ◽  
Adiko Serge-Bertrand
Keyword(s):  
Chemical Nature ◽  
Raw Materials ◽  
Complex Structure ◽  
Strength Properties ◽  
Raw Material ◽  
Low Molecular Weight ◽  
Catalytic Complex ◽  
Bituminous Materials ◽  
Heavy Oil Residues ◽  
Selection Of

The combination of the synthesized multicomponent bifunctional catalytic complex (MBC) components with heavy oil residues (HOR) of the paraffin-naphthenic (P-N) base leads to the chemical structuring of the hydrocarbon (HC) segments of the raw material molecules, and the specifics of HOR physicochemical structure, which will be the criteria for the selection of modifiers with a certain chemical nature [1,2,3,4]. It has been established that the introduction of catalytic activators in the tar composition promotes both the intensification of the oxidation process and the production of bituminous insulating material (BIM) with high physicomechanical properties [1,2,4].Raw materials for the production of special bituminous materials must be highly resinous with a P-HC content of up to 3% by weight. Based on the works by A.S. Kolbanovskaya [6], this is explained by the fact that the dispersed structure of bitumen is significantly dependent on the content of P-HC, since the dispersed phase in the oils is formed by naphthenic (N-) and PN-A-HC at certain temperatures with the side chains of the paraffinic P-HC series. If their content is more than 3% by weight the crystallization skeleton of P-HC is developed, which provides stiffness and reduces the plasticity interval for the system. Together with this, it is known that in the process of HOR oxidation the amount of low-molecular-weight oil A-HC decreases continuously, and the relative amount of PN-HC increases. Due to this, the affinity of the dispersion medium (DM) decreases to asphaltenes [7,8,9], which, moreover, becomes larger, which leads to THE deterioration of the cohesion and adhesion-strength properties of BIM.  

scholarly journals STUDY OF THE IMPACT OF THE INTRODUCTION OF SHAFT TECHNOLOGY DEVELOPMENT ON THE DILUTION OF INCLINED COAL SEAMS OF COMPLEX STRUCTURE

Ugol ◽  
2019 ◽  
pp. 16-19
Author(s):  
E.B. Shevkun ◽  
◽  
A.V. Leschinskiy ◽  
A.I. Dobrovolskiy ◽  
A.A. Galimyanov ◽  
...  
Keyword(s):  
Technology Development ◽  
Complex Structure ◽  
Coal Seams ◽  
The Impact

scholarly journals On the organization of excavation and transportation equipment in the coal-bearing zones at open pit mines

2021 ◽  
Vol 315 ◽  
pp. 01017
Author(s):  
Maxim Tyulenev ◽  
Sergey Markov ◽  
Oleg Litvin ◽  
Michal Cehlár ◽  
Yaroslav Litvin
Keyword(s):  
Complex Structure ◽  
Open Pit ◽  
Coal Seams ◽  
Open Pit Mines ◽  
Joint Development ◽  
Transportation Equipment ◽  
Development Procedure ◽  
Mining Works ◽  
Dispatching Control

One of the essential issues of the benches’ development procedure is the choice of the method of seam development in the complex structure: joint development of rock and coal seams in one complex face or their separate excavation in blocks of 50-100 m in length. The decision of this question is connected with the mode of mining works, represented by the schedule of stripping and winning works. The choice of one or another method is connected with operative-dispatching control of haul trucks delivery. When rock and coal are mined together in a complex face, overburden haul trucks should be supplied for loading rock and coal haul trucks for coal in turns. It is organizationally difficult to supply haul trucks of different purposes during the shift. It is necessary to proceed from the shift (daily) planning of haul trucks supply for specific faces. In addition, it is necessary to take into account that rock and coal faces are often located on opposite sides of the quarry pit. This article studies the issue of organizing the operation of excavation and loading equipment during the mining of the coal-bearing zone of the open pit in order to reduce the loss of output of haul trucks.

SEM Study of Tension Wood Fiber Morphology and its Effect on Paper Properties

1977 ◽  
Vol 35 ◽  
pp. 308-309
Author(s):  
K. W. Robinson
Keyword(s):  
Tension Wood ◽  
Wood Fiber ◽  
Strength Properties ◽  
Fiber Morphology ◽  
Paper Properties ◽  
Pure Cellulose ◽  
Short Rotation ◽  
Hardwood Trees ◽  
Sem Study

Tension wood (TW) is an abnormal tissue of hardwood trees; although it has been isolated from most parts of the tree, it is frequently found on the upper side of branches and leaning stems. TW has been classically associated with geotropic alignment, but more recently it has been associated with fast growth. Paper made from TW is generally lower in strength properties. Consequently, the paper industries' growing dependence on fast growing, short- rotation trees will result in higher amounts of TW in the final product and a corresponding reduction in strength.Relatively few studies have dealt with the role of TW in the structure of paper. It was suggested that the lower strength properties of TW were due to a combination of factors, namely, its unique morphology, compression failures in the cell wall, and lower hemicellulose content. Central to the unique morphology of the TW fiber is the thick gelatinous layer (G-layer) composed almost entirely of pure cellulose.

A new method of complex structure analysis by electron microscopy

1978 ◽  
Vol 36 (1) ◽  
pp. 628-629
Author(s):  
V.V. Rybin ◽  
E.V. Voronina
Keyword(s):  
Complex Structure ◽  
Reciprocal Lattice ◽  
Stacking Faults ◽  
Plastic Strains ◽  
Base Position ◽  
Structural Regularity ◽  
Orientation Matrix ◽  
Computerized Processing ◽  
Fully Automatic ◽  
Diffraction Patterns

Recently, it has become essential to develop a helpful method of the complete crystallographic identification of fine fragmented crystals. This was maainly due to the investigation into structural regularity of large plastic strains. The method should be practicable for determining crystallographic orientation (CO) of elastically stressed micro areas of the order of several micron fractions in size and filled with λ>1010 cm-2 density dislocations or stacking faults. The method must provide the misorientation vectors of the adjacent fragments when the angle ω changes from 0 to 180° with the accuracy of 0,3°. The problem is that the actual electron diffraction patterns obtained from fine fragmented crystals are the superpositions of reflections from various fragments, though more than one or two reflections from a fragment are hardly possible. Finally, the method should afford fully automatic computerized processing of the experimental results.The proposed method meets all the above requirements. It implies the construction for a certain base position of the crystal the orientation matrix (0M) A, which gives a single intercorrelation between the coordinates of the unity vector in the reference coordinate system (RCS) and those of the same vector in the crystal reciprocal lattice base : .

Sign in / Sign up

Export Citation Format

Share Document