scholarly journals Issues of Exploitation of Induction Motors in the Course of Underground Mining Operations

2017 ◽  
Vol 62 (3) ◽  
pp. 579-596 ◽  
Author(s):  
Stanisław Gumula ◽  
Wiktor Hudy ◽  
Malgorzata Piaskowska-Silarska ◽  
Krzysztof Pytel
Keyword(s):  
Induction Motors ◽  
Underground Mining ◽  
Mechanical Energy ◽  
Mining Industry ◽  
Electrical Energy ◽  
Mining Operations ◽  
Slip Ring ◽  
Input Signals ◽  
Large Distortion ◽  
Oriented System

Abstract Mining industry is one of the most important customers of electric motors. The most commonly used in the contemporary mining industry is alternating current machines used for processing electrical energy into mechanical energy. The operating problems and the influence of qualitative interference acting on the inputs of individual regulators to field-oriented system in the course of underground mining operations has been presented in the publication. The object of controlling the speed is a slip-ring induction motor. Settings of regulators were calculated using an evolutionary algorithm. Examination of system dynamics was performed by a computer with the use of the MATLAB / Simulink software. According to analyzes, large distortion of input signals of regulators adversely affects the rotational speed that pursued by the control system, which may cause a large vibration of the whole system and, consequently, its much faster destruction. Designed system is characterized by a significantly better resistance to interference. The system is stable with the properly selected settings of regulators, which is particularly important during the operation of machinery used in underground mining.

scholarly journals DETERMINANTS OF ACCIDENT IN THE MINES: A RETROSPECTIVE STATISTICAL ANALYSIS OF MINING ACCIDENTS IN GHANA

2020 ◽  
Vol 3 (2) ◽  
Author(s):  
Francis Frimpong ◽  
Kingsley Kwakye
Keyword(s):  
Statistical Analysis ◽  
Socioeconomic Development ◽  
Underground Mining ◽  
Current Trend ◽  
Mining Industry ◽  
Body Part ◽  
The Body ◽  
Mining Operations ◽  
Fatal Accident ◽  
Analytical Technique

The mining industry continues to be an important sector of the Ghanaian economy, contributing to the foreign exchange, employment and socioeconomic development after the colonial period. The current trend of mining operations requires greater skills and technical knowledge because they involve sophisticated machines, dangerous chemicals and explosive mechanisms, underground operations etc. Accidents in the mines just like any occupational accident may lead to deaths, injuries, disabilities and financial losses. One of the ways of improving occupational knowledge and skills is to acquire some level of understanding of accident causation mechanism. An analytical technique which will form the basis for accident and injury epidemiological studies is therefore necessary to ensure operational safety improvement. A retrospective statistical analysis of accidents in eight gold mining companies was undertaken through measures of association, hypothesis testing, trend analysis and predictive measurements. The results of the study indicate that 20% of accident cases resulted in deaths, 30% were serious and 50% minor accidents. Underground mining increases the risk fatal accident by 1.46, morning shift increases the risk of fatal accident by 4.81 and being a contract miner increases the risk of fatal accident by 1.05. The part of body injured can predict the degree of injury by reducing the error of prediction by 40.2%. Since proportion of accident fatalities increases with increasing age of miners, it is recommended that miners with higher age should not be task with high risk jobs. It is recommended again that, miners should be given improved protective clothes to guide against occurrences of fatal incidents. Especially, clothes to cover the head and upper part of the body since they top the fatality chart and the fact that fatality is strongly associated with body part. <p> </p><p><strong> Article visualizations:</strong></p><p><img src="/-counters-/edu_01/0720/a.php" alt="Hit counter" /></p>

Irkutsk school of mining engineers is celebrating 90th anniversary

2021 ◽  
Vol 44 (4) ◽  
pp. 358-368
Author(s):  
B. L. Talgamer
Keyword(s):  
Underground Mining ◽  
Mining Industry ◽  
Gold Deposits ◽  
Educational Process ◽  
Open Pit ◽  
Mineral Deposits ◽  
Mining Institute ◽  
Mining Operations ◽  
Design Work ◽  
Research And Design

It is in 1930 that the training of mining engineers began in Eastern Siberia on the basis of the Siberian Mining Institute (now Irkutsk National Research Technical University). In 1931 the Department of Mining Arts was organized, which later was named the Department of Mineral Deposits Development. Over the years, the Department has trained more than 7000 graduates – mining engineers, who made a huge contribution in the development of the mining industry in the Irkutsk region and neighboring territories including Mongolia. The Department has trained more than a hundred mining engineers and Masters of science for Mongolia; assisted the lecturers and professors of the Mongolian Polytechnic University (now Mongolian University of Science and Technology) in organizing the educational process for training specialists for the country's mining industry. At its different formation stages the Department of Mineral Deposits Development was headed by well-known scientists – mining engineers, who created three scientific schools for the development of coal, placer and gold deposits; the obtained scientific results were marked with two State awards of the Russian Federation, dozens of doctoral and candidate dissertations were defended and about 100 patents were received. Today, the Department super- vises the training of mining engineers in open-pit and underground mining of mineral deposits, carries out a large amount of research and design work on the orders from mining enterprises, trains academic staff, develops new technologies and technical solutions in order to improve mining operations. The Department is deeply involved in the cooperation with mining enterprises, research and design organizations, as well as with universities that train mining engineers.

Types of Faults and Condition Monitoring Methods of Induction Motors

2019 ◽  
pp. 131-162
Author(s):  
Maheswari M. ◽  
Gunasekharan S
Keyword(s):  
Induction Motors ◽  
Supply Voltage ◽  
Raw Materials ◽  
Mechanical Energy ◽  
Electrical Energy ◽  
Constant Speed ◽  
Working Environment ◽  
Monitoring Methods ◽  
Bearing Fault ◽  
Complete Failure

Induction motors are the electromechanical devices used to convert electrical energy into mechanical energy and work under the principle of mutual inductance. They have stator and rotor as two major parts. They run at constant speed when the supply voltage and frequency are constant and are suited for constant speed drives. They have rugged construction but working environment causes different faults. As per IEEE and EPRI study on induction motor faults, bearing fault and stator faults are 46% and 36%, respectively. The broad categories of the fault are stator winding fault, broken rotor fault, rotor mass unbalance fault, bowed rotor faults, single phasing fault, bearing fault, and crawling. Unbalanced stator voltage and current, oscillations in torque, drop in efficiency and torque, overheating and unwarranted vibration are the effects of these faults. Undetected faults cause complete failure of motor and it is costly in terms of lost production time, maintenance cost, and wasted raw materials.

Human Factors in Underground Metal and Nonmetal Mining

1980 ◽  
Vol 24 (1) ◽  
pp. 175-179
Author(s):  
William H. Crooks ◽  
Norman D. Schwalm ◽  
James M. Peay
Keyword(s):  
Research And Development ◽  
Human Factors ◽  
Underground Mining ◽  
Mining Industry ◽  
Mining Operations ◽  
Work Site ◽  
Site Characteristics ◽  
Mining Coal ◽  
Human Factors Research

The study describes the environmental, job, and work site characteristics of underground metal and nonmetal mining operations from a human factors viewpoint. Attention is given to the problems associated with the man-machine-environment interface in underground mining and to the accidents and injuries associated with underground mining operations. Differences in methods and equipment used in mining metal and nonmetal materials versus those used in mining coal are noted. Problem areas in the metal and nonmetal mining industry that would benefit from further human factors research and development are outlined.

scholarly journals Prospects for resuming the underground development of magnetite quartzites in Ukraine, mining, technological and economic aspects

2018 ◽  
pp. 45-52
Author(s):  
S.O. Popov ◽  
V.M. Sidor ◽  
V.A. Novik
Keyword(s):  
Economic Efficiency ◽  
Iron Ore ◽  
Underground Mining ◽  
Mining Industry ◽  
Operating Conditions ◽  
Raw Material ◽  
Material Base ◽  
Economic Aspects ◽  
Mining Operations ◽  
Magnetite Quartzite

Purpose. Substantiation of expediency and prospects for resuming the development of magnetite quartzites by underground method in Ukraine. Methodology. Analysis of literature sources, project documentation and practical data that contain information on the current state and conditions for the development of iron ore in Ukraine, as well as data on varieties and state of reserves of different types of these ores. Findings. The problem, faced by domestic iron ore mining enterprises in connection with reaching the large depths of mining operations and the emergence of a shortage of raw material resources, is described. The volumes of magnetite quartzites, which are contained in the dormant mines, operating mines, and those mines of Ukraine that are not currently in operation, are determined. The expediency and directions for resuming the development of these ores, as well as expanding the raw material base of the domestic iron ore mining industry, are justified. Originalty. The principal approaches to the implementation at a modern technological and technical level of the cyclic-flow underground mining technology for the development of magnetite quartzite reserves, which is capable of ensuring the economic efficiency of their extraction at depths where the open method of their development becomes unprofitable, are expanded. Practical value. Ensuring the economic efficiency of underground development of magnetite quartzite reserves in operating conditions of the iron ore mining enterprises of Ukraine leads to a significant expansion of their raw material base, which is currently constantly decreasing, as well as support of the production capacity of these enterprises for a long period of time, and allows Ukraine to remain one of the leaders in the iron ore mining industry in the world. Key words: prospects, underground mining, magnetite quartzites, mining, technological, economic aspects.

scholarly journals MODELLING-FRIENDLY LIFE CYCLE INVENTORY OF UNDERGROUND MINING OF BAUXITE: A CASE STUDY FROM JAJCE MINES IN BOSNIA AND HERZEGOVINA

2021 ◽  
Vol 36 (3) ◽  
pp. 59-76
Author(s):  
Anamarija Grbeš ◽  
Ivo Galić ◽  
Branimir Farkaš ◽  
Ivan Budeš
Keyword(s):  
Life Cycle ◽  
Bosnia And Herzegovina ◽  
Life Cycle Inventory ◽  
Fossil Fuels ◽  
Underground Mining ◽  
Mechanical Energy ◽  
Mining Industry ◽  
Compressed Air ◽  
Sublevel Caving ◽  
The Impact

The objective of this paper is the study of the life cycle inventory (LCI) for underground mining of small, clustered deposits of Dinaric Alps-type bauxites, mined in the mountains near Jajce, a town in Bosnia and Herzegovina, in the period 2010-2020. Modelling of the life cycle inventory was done based on the company’s internal reports and project documentation for a variant of the sublevel caving method that involves drilling and blasting. Four mines, located on three exploitation fields, were found in different phases of mine life, different levels of tectonic disturbances and different types of energy: diesel, electricity, and compressed air. The main results of this study are the inventory of underground bauxite exploitation made based on long-term data, the life cycle of one bauxite deposit, and the emission factors from blasting. Underground mining in this case proved to be energy intensive: an average of 52-92 MJ/t was required (as opposed to 37 MJ/t for surface bauxite exploitation in Italy). At the same time, underground bauxite exploitation caused only 5.6-6.4% of the transformation of natural land that is above the mines and deposits. The operations relying on diesel fuel caused local emissions in the air and underground. The operation relying on electricity for DC locomotive and generation of the compressed air were without local emission into the air, although energy efficiency was probably reduced using compressed air as mechanical energy. At the state level, the impact depends on the country’s energy mix, which is still quite dependent on fossil fuels. Engineering estimates of blasting emissions indicated detonators and ammonium nitrate explosives as a potentially important source of environmental impact. The mining industry would significantly benefit from cleaner energy in electricity generation (the energy sector) in Bosnia and Herzegovina. The path of air emissions in the underground system, especially lead and nitrogen compounds, needs to be further explored.

HIL Simulation of a Track Type Tractor for Autonomous Controller Testing

2008 ◽  
Author(s):  
Nicolas Sleiman ◽  
Julie A. Reyer
Keyword(s):  
Mining Industry ◽  
Simulated Data ◽  
Soil Conditions ◽  
Hardware In The Loop ◽  
Mining Operations ◽  
Input Signals ◽  
Control Modules ◽  
Earthmoving Equipment ◽  
Digital Or ◽  
Hil Simulation

The mining industry is introducing several autonomous mining operations, however the development of these algorithms is extremely expensive. This paper discusses the integration of a Hardware In the Loop (HIL) simulation to earthmoving equipment to aid in the development of autonomous mining operations. The benefit of this simulation is to save time and money for engineers developing the autonomous features. The hardware setup contained machine components that were connected to the Electronic Control Modules (ECMs). The ECMs used in the lab setup were the same as those on the actual tract type tractors. Those ECMs receive input signals based on which they command the solenoids. The HIL simulator converts the analog outputs into digital ones. Then the HIL sends out digital or simulated outputs to the ECMs such as pressure and fuel levels. The results of this work compare simulated data and real machine test data of an autonomous feature. A comparison is presented between the autonomous feature and a human operator. Finally potential of the HIL is demonstrated examining the autonomous feature with different soil conditions.

Reduction of structural vibrations with the piezoelectric stacks ring

2020 ◽  
Vol 64 (1-4) ◽  
pp. 729-736
Author(s):  
Jincheng He ◽  
Xing Tan ◽  
Wang Tao ◽  
Xinhai Wu ◽  
Huan He ◽  
...  
Keyword(s):  
Vibration Control ◽  
Mechanical Energy ◽  
Electrical Energy ◽  
Structural Vibrations ◽  
Rotor Systems ◽  
Fea Model ◽  
Piezoelectric Stacks ◽  
Shunt Damping ◽  
Reduction Effect ◽  
Euler Bernoulli Beam

It is known that piezoelectric material shunted with external circuits can convert mechanical energy to electrical energy, which is so called piezoelectric shunt damping technology. In this paper, a piezoelectric stacks ring (PSR) is designed for vibration control of beams and rotor systems. A relative simple electromechanical model of an Euler Bernoulli beam supported by two piezoelectric stacks shunted with resonant RL circuits is established. The equation of motion of such simplified system has been derived using Hamilton’s principle. A more realistic FEA model is developed. The numerical analysis is carried out using COMSOL® and the simulation results show a significant reduction of vibration amplitude at the specific natural frequencies. Using finite element method, the influence of circuit parameters on lateral vibration control is discussed. A preliminary experiment of a prototype PSR verifies the PSR’s vibration reduction effect.

The Nature of Mining-Induced Horizontal Displacement of Surface on the Example of Several Coal Mines

2014 ◽  
Vol 59 (4) ◽  
pp. 971-986 ◽  
Author(s):  
Krzysztof Tajduś
Keyword(s):  
Underground Mining ◽  
Mining Industry ◽  
Horizontal Displacement ◽  
Surface Slope ◽  
Proportionality Coefficient ◽  
Model Studies ◽  
Displacement Vectors ◽  
Mining Conditions ◽  
Design Projects ◽  
Academy Of Sciences

Abstract The paper presents the analysis of the phenomenon of horizontal displacement of surface induced by underground mining exploitation. In the initial part, the basic theories describing horizontal displacement are discussed, followed by three illustrative examples of underground exploitation in varied mining conditions. It is argued that center of gravity (COG) method presented in the paper, hypothesis of Awierszyn and model studies carried out in Strata Mechanics Research Institute of the Polish Academy of Sciences indicate the proportionality between vectors of horizontal displacement and the vector of surface slope. The differences practically relate to the value of proportionality coefficient B, whose estimated values in currently realized design projects for mining industry range between 0.23r to 0.42r for deep exploitations, whereas in the present article the values of 0.33r and 0.47r were obtained for two instances of shallow exploitation. Furthermore, observations on changes of horizontal displacement vectors with face advancement indicated the possibility of existence of COG zones above the mined-out field, which proved the conclusions of hitherto carried out research studies (Tajduś 2013).

scholarly journals Geological CO2 quantified by high-temporal resolution stable isotope monitoring in a salt mine

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Alexander H. Frank ◽  
Robert van Geldern ◽  
Anssi Myrttinen ◽  
Martin Zimmer ◽  
Johannes A. C. Barth ◽  
...  
Keyword(s):  
Temporal Resolution ◽  
Underground Mining ◽  
Stable Carbon Isotope ◽  
Underground Mines ◽  
Background Concentration ◽  
High Temporal Resolution ◽  
Salt Mine ◽  
Gas Migration ◽  
Mining Operations ◽  
Anthropogenic Contributions

AbstractThe relevance of CO2 emissions from geological sources to the atmospheric carbon budget is becoming increasingly recognized. Although geogenic gas migration along faults and in volcanic zones is generally well studied, short-term dynamics of diffusive geogenic CO2 emissions are mostly unknown. While geogenic CO2 is considered a challenging threat for underground mining operations, mines provide an extraordinary opportunity to observe geogenic degassing and dynamics close to its source. Stable carbon isotope monitoring of CO2 allows partitioning geogenic from anthropogenic contributions. High temporal-resolution enables the recognition of temporal and interdependent dynamics, easily missed by discrete sampling. Here, data is presented from an active underground salt mine in central Germany, collected on-site utilizing a field-deployed laser isotope spectrometer. Throughout the 34-day measurement period, total CO2 concentrations varied between 805 ppmV (5th percentile) and 1370 ppmV (95th percentile). With a 400-ppm atmospheric background concentration, an isotope mixing model allows the separation of geogenic (16–27%) from highly dynamic anthropogenic combustion-related contributions (21–54%). The geogenic fraction is inversely correlated to established CO2 concentrations that were driven by anthropogenic CO2 emissions within the mine. The described approach is applicable to other environments, including different types of underground mines, natural caves, and soils.

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