INFLUENCE OF OVERSIZE YIELD FOR THE PRODUCTIVITY OF LOADERS

2021 ◽  
Vol 4 (1) ◽  
pp. 284-294
Author(s):  
S. А. Vohmin ◽  
◽  
A. K. Kirsanov ◽  
G.S. Kurchin ◽  
E.V. Shevnina ◽  
...  
Keyword(s):  
Rock Mass ◽  
Research Methodology ◽  
Underground Mines ◽  
Actual Output

Industrial observations were carried out to determine the actual output of oversized mines at underground mines (excluding nonmetallic ones) of the Norilsk Nickel. The research methodology provided for measuring the actual output of oversized after borehole breaking of ore massifs of chambers at the underground mines "Oktyabrsky", "Taimyrsky", "Komso-molsky", "Zapolyarny" and "Mayak" of the ZF Norilsk Nickel. A decrease in the productivity of loading and transport vehicles for the shipment of rock mass from the chambers through a re-duction factor associated with the percentage of oversized cargo is determined.

scholarly journals Study on the Deformation Mechanism of Soft Rock Roadway under Blasting Disturbance in Baoguo Iron Mine

2018 ◽  
Vol 2018 ◽  
pp. 1-12
Author(s):  
Hong-di Jing ◽  
Yuan-hui Li ◽  
Kun-meng Li
Keyword(s):  
Rock Mass ◽  
Deformation Mechanism ◽  
Soft Rock ◽  
Deformation Monitoring ◽  
Underground Mines ◽  
Blasting Vibration ◽  
Iron Mine ◽  
The Stability ◽  
Soft Rock Roadway ◽  
Rock Roadway

In order to study the deformation mechanism of soft rock roadway in underground mines, it is necessary not only to study the influence of the dynamic disturbance caused by the cyclic mining blasting vibration on the stability of the soft rock roadway but also to study the degradation of the roadway surrounding rock itself and other factors. The paper presented a synthetic research system to investigate the factors that influence roadway rock structure deterioration in Baoguo Iron Mine. Firstly, the stability of rock mass was analyzed from the perspective of the physical and structural characteristics of the rock mass. Afterwards, according to monitoring data of mining blasting vibration, a suitable safety blasting prediction model for Baoguo Iron Mine was determined. And then, combining the results of mining blasting vibration monitoring and deformation monitoring, the effect of cyclic mining blasting on the stability of the soft rock roadway was obtained. By systematically studying the intrinsic factors of rock quality degradation and external environmental disturbances and their interactions, this paper comprehensively explores the deformation mechanism of soft rock roadway and provides the support for fundamentally solving the large deformation problems of soft rock roadway in underground mines.

scholarly journals Automatic Classification of Microseismic Signals Based on MFCC and GMM-HMM in Underground Mines

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Pingan Peng ◽  
Zhengxiang He ◽  
Liguan Wang
Keyword(s):  
Rock Mass ◽  
Gaussian Mixture ◽  
Automatic Classification ◽  
Microseismic Monitoring ◽  
Underground Mines ◽  
Basic Step ◽  
Microseismic Data ◽  
Safety Risks ◽  
Microseismic Events

In order to mitigate economic and safety risks during mine life, a microseismic monitoring system is installed in a number of underground mines. The basic step for successfully analyzing those microseismic data is the correct detection of various event types, especially the rock mass rupture events. The visual scanning process is a time-consuming task and requires experience. Therefore, here we present a new method for automatic classification of microseismic signals based on the Gaussian Mixture Model-Hidden Markov Model (GMM-HMM) by using only Mel-frequency cepstral coefficient (MFCC) features extracted from the waveform. The detailed implementation of our proposed method is described. The performance of this method is tested by its application to microseismic events selected from the Dongguashan Copper Mine (China). A dataset that contains a representative set of different microseismic events including rock mass rupture, blasting vibration, mechanical drilling, and electromagnetic noise is collected for training and testing. The results show that our proposed method obtains an accuracy of 92.46%, which demonstrates the effectiveness of the method for automatic classification of microseismic data in underground mines.

scholarly journals Stability of a rock mass using the key block theory: a case study

2020 ◽  
Vol 150 ◽  
pp. 03024
Author(s):  
Y. Zerradi ◽  
A. Lahmili ◽  
M. Souissi
Keyword(s):  
Rock Mass ◽  
Underground Mines ◽  
The Finite Element Method ◽  
Empirical Methods ◽  
Mining Operations ◽  
Initial Equilibrium State ◽  
Eastern Zone ◽  
Geometrical Data ◽  
Key Block

In underground mines, excavating disturb the initial equilibrium state of the rock mass, and therefore require selection of a support in order to control the movement of rocks, avoid landslide and work safely. Thus, the progress of mining operations in the ST2 mineralization, in the eastern zone of the Bouazzer mine, is disrupted because of stability problems. On the basis of field observations and analyzes of core drill, the geological and structural study, carried out in this area, has shown the existence of three types of facies: altered and cracked diorite, cobaltiferous mineralization which is in contact with serpentinites. In fact, the empirical methods such as Barton, Bieniawski and the recommendations of the AFTES have qualified the rock mass as poor, furthermore they proposed as kind of supports: steel arches, shotcrete and rock-bolts. Numerical simulation by the finite element method proved to be very complex due to existence of several types of discontinuities (faults, shistosities and joints).These discontinuities are natural fractures that delimit various shapes and sizes of wedges, which can become detached from the roof or siding of the excavation and collapse under their own weight. Although the empirical methods cited above provide supports for each facies, however, this support is expensive and difficult to implement in practice because it must cover the entire surface of the excavation and thus not allowing to detect stable blocks that do not require a support. For this it was essential to carry out an analysis of wedges to better locate unstable blocks. The treatment of fracturing data has highlighted the presence of five sets of discontinuities of which three sets are principals and the other two are minor joints. Then, while taking into account the geometrical, mechanical data of the discontinuities as well as the geometrical data of the excavation, we were able to detect the shape and the size of the unstable blocks and the sets of discontinuities delimiting them and which favor their sliding and tilting. Thus, we calculated the number of anchor bolts needed to stabilize these blocks in order to ensure an acceptable safety factor. This study shows clearly how a wedge analysis of the rock mass can guide and optimize the support work.

scholarly journals Enhancement of the technology of mining steep ore bodies applying the “floating” crown

2021 ◽  
Vol 280 ◽  
pp. 08013
Author(s):  
Serhii Pysmennyi ◽  
Serhii Chukharev ◽  
Kyelgyenbai Khavalbolot ◽  
Iryna Bondar ◽  
Jambaa Ijilmaa
Keyword(s):  
Rock Mass ◽  
Rock Pressure ◽  
Iron Content ◽  
Iron Ore ◽  
Underground Mines ◽  
Protective Structure ◽  
Unit Load ◽  
Block Caving ◽  
Crown Length ◽  
Ore Bodies

When mining ore bodies in Kryvyi Rih iron ore basin, underground mines apply open stoping or bulk caving systems in proportion of 55% to 45%. Most of underground mines prefer stoping with pillar caving. Yet, rock pressure contributes to growth of costs for workings maintenance and deterioration of extraction indices. Rock mass extraction indices can be enhanced by application of a protectve structure in the upper part of the block that will enable additional decrease in load on the draw level. There are a great many of methods for determining parameters of constructive elements of the protective structure that help keep its integrity for the whole period of block mining. The article suggests methods for determining parameters of the protective structure when mining steep ore bodies. The research conducted demonstrates that with the inclined protective structure, increase of unit load on it from 200 to 1200t/m2 leads to decrease of its thickness from 6.3-20.9m to 5.5-18.4m and increase of the crown length from 40m to 60m. The developed block caving system with application of the protective structure when mining steep ore bodies enables overall decrease of ore dilution in the block by 3%, increase of iron content in the mined ore by 1.3% without significant mining costs growth and decrease of loads on the workings of the receiving level.

scholarly journals Method for Radioactive Waste Disposal in Underground Mines

2021 ◽  
Vol 15 (2) ◽  
pp. 49-62
Author(s):  
E. V. Kuzmin ◽  
◽  
A. V. Kalakutsky ◽  
A. A. Morozov ◽  
◽  
...  
Keyword(s):  
Rock Mass ◽  
Radioactive Waste ◽  
Radioactive Waste Disposal ◽  
Underground Mines ◽  
Regulatory Requirements ◽  
Paper Briefly ◽  
Geomechanical Properties ◽  
Ore Processing ◽  
Underground Disposal ◽  
State Corporation

This paper presents the key parameters associated with the disposal method used to dispose of radioactive waste (RW) of Class 2 and 3 in abandoned underground mines of PIMCU site assuming additional isolation of RW containers, adjustment of bedrock geomechanical properties and compliance with regulatory requirements. The paper briefly analyzes international practices focused on RW disposal in natural and artificial underground cavities. It provides a comparison between the forecasted volumes of RW generation at the enterprises of the State Corporation Rosatom and the available underground disposal capacity at PIMCU site. It presents the main characteristics of a paste filling manufactured based on materials from uranium ore processing and used as an insulating filler inside the vaults. The paper summarizes the results of operations on rock mass reinforcement based on an injection method. It indicates the key advantages of the proposed method.

scholarly journals The Impact of the Rock Mass Deformation on Geometric Changes of a Historical Chimney in the Salt Mine of Bochnia

2018 ◽  
Vol 35 ◽  
pp. 04002
Author(s):  
Anna Szafarczyk ◽  
Rafał Gawałkiewicz
Keyword(s):  
Rock Mass ◽  
Laser Scanning ◽  
Underground Mines ◽  
Salt Mine ◽  
Internal Factors ◽  
Rock Mass Deformation ◽  
Structural Surface ◽  
Geometry Measurement ◽  
Geometric Changes ◽  
The Impact

There are many ways of the geometry measurement of slim objects, with the application of geodetic and photogrammetric methods. A modern solution in the diagnostics of slim objects is the application of laser scanning, with the use of a scanner of a scanning total station. The point cloud, obtained from the surface of the scanned object gives the possibility of generating not only information on structural surface deformations, but also facilitates obtaining the data on the geometry of the axis of the building, as a basic indicator of the characteristics of its deformation. The cause of the change in the geometry of slim objects is the impact of many external and internal factors. These objects are located in the areas of working or closed underground mines. They can be impacted by the ground and they can face the results of the convergence of cavities. A specific structure of the salt rock mass causes subsequent convergence of the post-exploitation cavities, which has the influence on the behaviour of the terrain surface and the related objects. The authors analysed the impact of the changes in the rock mass and the surface on the changes of the industrial chimney in the Bochnia Salt Mine.

Three-Dimensional Numerical Simulation of the Mass Exchange Between Longwall Headings and Goafs, in the Presence of Methane Drainage in A U-Type Ventilated Longwall / Symulacja Numeryczna 3D Procesów Wymiany Masy W Układzie Wyrobiska Ścianowe Zroby, W Aspekcie Prowadzenia Odmetanowania Ściany Przewietrzanej Systemem Na „U”

2013 ◽  
Vol 58 (3) ◽  
pp. 705-718
Author(s):  
Przemysław Skotniczny
Keyword(s):  
Numerical Simulation ◽  
Rock Mass ◽  
Coal Seam ◽  
Mass Exchange ◽  
Experimental Analysis ◽  
Three Dimensional ◽  
Underground Mines ◽  
Test Cases ◽  
Methane Drainage ◽  
Invaluable Tool

Abstract The phenomena related to the occurrence of methane in underground mines pose a considerable danger in the process of coal seam exploitation. Quite often, experimental analysis falls short of investigating their areas of origin (goafs area, affected rock mass, the tail gate area with abandoned excavation). Therefore, an invaluable tool for evaluating the risk involved in the exploitation process might be the numerical simulation of the phenomenon in question, carried out with the use of the latest CFD methods. Due to its application, we are able to recreate and predict the mechanism of the studied phenomenon, with certain assumptions and simplifications made. The present paper discusses the results of the numerical simulation of the process of mass exchange occurring between affected rock mass and longwall headings. The calculations were performed for two test cases - 100 meter long walls.

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