Application In Mining Industry Research Articles

Composition and treatment of wear resistant steel for application in mining industry

The service life of machines in the mining industry is in the most cases determined by wear rate of parts in contact with the rock and soil. This work demonstrates the results of investigation on wear resistance of high-carbon low-alloy steel under abrasive wear. Steel samples containing 1.2 wt.% of carbon, 3 wt.% of manganese and 2 wt.% of silicon were hardened from 900 °C and 1000 °C and subjected to two-body and three-body abrasion tests. It has been established that after heat treatment this steel has increased abrasive wear resistance due to the phase transformation of unstable austenite into deformation-induced martensite. The results of study of near-surface region microstructure of samples after wear are presented. X-ray diffraction analysis and measurement of the microhardness of the worn surface were also carried out. It has been established that during abrasive wear a continuous layer of deformation martensite with a microhardness of 1300-1400 HV 0.05 is formed at a depth of up to 10 μm. Such a microhardness significantly exceeds the microhardness of quenching martensite. The results of the work can be used to increase the service life of wear parts of mining equipment.

Modern Conveyor Pulleys with Modified End Disc Design, Locking Device & Gearless Drive

Nowadays, in order to mine the ore economically, it became necessary to increase the tonnage of mined ore, as well as to improve the method of transporting the ore that is to be mined. Belt conveyors are essential equipment for transferring the material from one place to targeted place and conveyor pulleys are the major component of conveyor system. Such kind of conveyor system needs reliable conveyor pulleys. Different type of conveyor pulleys are used throughout the conveyor system as per their function. In this research, the agenda is on modification of present conveyor pulley design by removing the most common causes of catastrophic fatigue failure which are used for high tension application in mining industry. The target during the research is on improvement of end disc design, elimination keyed connection in between shaft and hub by using locking device. The another development is to use of gearless drive technology for drive pulleys. This is obtained by continuous improvement and strategic standardized process to cater the need of mining application. These modified conveyor pulleys are best suitable for high capacity, high tension long distance conveyors used in mining industry.

MINING APPLICATIONS OF IMMOBILIZED MICROBIAL CELLS IN AN ALGINATE MATRIX: AN OVERVIEW

Immobilized microbial cells have been used extensively in various industrial processes. However, immobilized cells have not been used widely for mining industrial applications. Cell immobilization consists of a technique by which microorganisms are confined through physical or chemical interactions in a matrix, or fixed to the surface of the immobilizing agent. In recent years, entrapment of cells within spheres of Ca2+ alginate has become the most widely used technique for immobilizing living cells. This review examines many of the scientific and technical aspects involved in using Ca2+ alginate immobilized microbial cells in mining activities, with a particular focus on the biohydrometallurgical industrial applications and processes of soil bioremediation in heavy metal contaminated mining areas, environmental recovery of atmospheric emissions containing H2S and treatment of acid mine drainage.

Enhancing Energy Efficiency of Wireless Sensor Network for Mining Industry Applications

Abstract Recent advances in sensing modules and radio technology will enable small but smart sensors to be deployed for a wide range of environmental monitoring applications. They collect data from different environment or infrastructures in order to send them to the cloud using different communications platforms. These data can be used to provide smarter services. However, they are various issues and challenges related to the ubiquitous sensors that should be solved. In this paper we interest on analysis of wireless sensor network from an energy management perspective. The idea behind the energy-efficiency wireless sensor networks is that each node can only transmit to a limited number of other nodes directly. The limited resources of nodes imply that the transmission range is limited. In order to transfer the data to the final destination, the traffic must be relayed using intermediate nodes, creating a multi-hop route. The total energy consumption associated with an end-to-end transmission over such a route can be significantly reduced if the nodes are correctly configured. In this paper, underground mine monitoring system is presented with an overview of the related issues and challenges such as reliability, cost, and scalability.

Laser re-manufacturing of failure 18Cr2Ni4WA gear in low-speed heavy-load mining machine transmission

This article investigated laser re-manufacturing technology application in mining industry. The research focused on green re-manufacturing of failure spur. Leave the main gear body stay intact after the dirty, rust, fatigue and injured part were removed completely before the green re-manufacturing procedure begin. The optimized laser operating parameters paved the road for excellent mechanical properties and comparatively neat shape which often means less post processing. The laser re-manufactured gear surface was systematically examined, including microstructure observation, and dry wear test at room temperature. The test results were compared with new gear surface and used but not broken gear surface. Finally, it proved that the green re-manufactured gear surface displayed best comprehensive mechanical properties, followed the new gear surface. The resistance of dry wear properties of used but not broken gear surface was the worst.

A combined photovoltaic and novel renewable energy system: An optimized techno-economic analysis for mining industry applications

The productivity of the mining industry in Chile, currently the main driver of Chilean economy, is closely tied to foreign demand for ores. Ore-processing is known for involving energy–intensive processes, such as comminution, concentrating and cathodic processes. As mining activities take place in the arid north of Chile, they are affected by water scarcity. Water shortage has forced the industry to pump desalinated seawater up to mining sites over 2000 m above sea level, further increasing electricity consumption. Given these energy needs, and the fact that electrical energy supply in the north of Chile is based on fossil fuels, it is important to consider the use of renewable energies as environment-friendly and economic alternatives. The aim of this work is to evaluate, by an optimized techno-economic analysis, the use of photovoltaic and a novel wind-based technology to supply at least 10% of the current and the predicted electrical energy requirements of the mining industry in the Antofagasta region. A combination of an optimization problem and technical evaluation was performed using Matlab to obtain the optimal number of solar and wind-based technology units in a case study. Total energy generation from a novel wind-based technology unit is 67,616 MWh/y, corresponding to 14.45·106 Nm3 (1298 t) of hydrogen and 7.41·106 Nm3 (10,323 t) of oxygen after electrolytical transformation. Considering a 65% efficiency of the combined cycle fed with hydrogen and oxygen, 28,133 MWh/y of electrical energy would be obtained. For the cases studied the cost of energy from the combined system was estimated to be between 0.255 US$/kWh and 0.273 US$/kWh, slightly higher than the average energy regional cost. According to the analysis, the renewable energy system could be a sustainable alternative to supply economic green energy to the mining industry in Chile.

Standardization of a method for studying susceptibility of Indian coals to self-heating

This paper establishes the standardization of an electro-chemical method called wet oxidation potential (WOP) technique for determining the susceptibility of coal to spontaneous combustion. A total of 78 coal samples collected from 13 different mining companies, spread over most of the Indian Coalfields, have been used for this investigation. Experiments were carried out at different concentrations of KMnO4, viz., 0.05, 0.1, 0.15, and 0.2 N in 1 N KOH and at 27, 40, and 45 °C. With a combination of different concentrations of KMnO4 and temperature, 12 experiments were carried out for each coal sample. Altogether, 936 experiments have been carried out by adopting different experimental conditions to standardize WOP method for wider applications in mining industries. Physical, chemical, and petrographical compositions of coal samples were studied by proximate, ultimate, and petrographic analyses. In order to determine the best combinations of experimental conditions to achieve optimum results in wet oxidation potential method, results were first analyzed by principal component analysis and then by artificial neural network analysis. These analyses clearly reveal that susceptibility index “rate of reduction of potential difference” (RPD12), keeping experimental condition with 0.2 N KMnO4 in 1 N KOH solution at 45 °C, produces optimal results in finding out the susceptibility of coal to spontaneous heating. Further, coals are classified according to their proneness to spontaneous heating with multilayer perceptron (MLP) classifier. A correct classification with accuracy of 94.29 % on test data has been achieved with this classifier. The results have been further validated by tenfold cross-validation method to show its consistent performance over the chosen features.

Bio-Oxidation and Biocyanidation of Refractory Mineral Ores for Gold Extraction: A Review

Bioleaching has emerged as a green technology with promising applications in mining industries in the context of recovery of precious metals from mineral ores. The authors synthesize the current knowledge available in the bioleaching of gold (Au) from ores by bringing together historical developments and recent endeavors. In addition, the role of the microbial community in the bio-oxidation of refractory ores for removal of base metal impurities and in the recovery of Au based on biocyanidation is reviewed. They also address the future research directions in the bioleaching of Au in order to make further advances toward practical industrial applications.

Method of the production cycle duration time modeling within hard coal longwall faces / Metoda probabilistycznego modelowania czasu trwania czynności cyklu produkcyjnego realizowanego w przodkach ścianowych kopalń węgla kamiennego

Method of probabilistic modeling of the production cycle duration time within hard coal longwall faces has been described in the present study. Duration of these activities for various technologies, including probabilistic schemes modeling have been described in the introduction. In order to illustrate the described method, an example of probabilistic modeling for data obtained from specific longwall face has been presented. The final chapters entitled “The possibility of Using the method” and “Results” contain information on the perspective of the method application in mining industry.

Emerging trends in information and communication technology in mine safety and disaster management

There is tremendous growth in the use of Geographic Information Systems (GIS), Global Positioning Systems (GPS), Remote Sensing, Satellite Communication, and Modeling & Simulation techniques. These tools and techniques helps significantly in characterizing infrastructure, risk area and disaster zones, planning and implementation of hazards reduction measures etc. Communication satellites becomes vital for providing emergency communication and timely relief measures. Integration of space technology inputs into natural disaster monitoring and mitigation mechanisms is critical for hazard reduction. This paper mainly focused on all the issues described above. Major emphasis had been given to the recent developments in information & communication technology enabled tools and their applications in mining industries for safe mining operations with increased productivity.

Statistical models of brittle fragmentation

Recent developments in statistical models for fragmentation of brittle material are reviewed. The generic objective of these models is understanding the origin of the fragment size distributions (FSDs) that result from fracturing brittle material. Brittle fragmentation can be divided into two categories: (1) Instantaneous fragmentation for which breakup generations are not distinguishable and (2) continuous fragmentation for which generations of chronological fragment breakups can be identified. This categorization becomes obvious in mining industry applications where instantaneous fragmentation refers to blasting of rock and continuous fragmentation to the consequent crushing and grinding of the blasted rock fragments. A model of unstable cracks and crack-branch merging contains both of the FSDs usually related to instantaneous fragmentation: the scale invariant FSD with the power exponent (2−1/D) and the double exponential FSD which relates to Poisson process fragmentation. The FSDs commonly related to ...

Selective Adhesion of Thiobacillus ferrooxidans to Pyrite

Bacterial adhesion to mineral surfaces plays an important role not only in bacterial survival in natural ecosystems, but also in mining industry applications. Selective adhesion was investigated with Thiobacillus ferrooxidans by using four minerals, pyrite, quartz, chalcopyrite, and galena. Escherichia coli was used as a control bacterium. Contact angles were used as indicators of hydrophobicity, which was an important factor in the interaction between minerals and bacteria. The contact angle of E. coli in a 0.5% sodium chloride solution was 31 degrees , and the contact angle of T. ferrooxidans in a pH 2.0 sulfuric acid solution was 23 degrees . E. coli tended to adhere to more hydrophobic minerals by hydrophobic interaction, while T. ferrooxidans selectively adhered to iron-containing minerals, such as pyrite and chalcopyrite. Ferrous ion inhibited the selective adhesion of T. ferrooxidans to pyrite competitively, while ferric ion scarcely inhibited such adhesion. When selective adhesion was quenched by ferrous ion completely, adhesion of T. ferrooxidans was controlled by hydrophilic interactions. Adhesion of E. coli to pyrite exhibited a liner relationship on langmuir isotherm plots, but adhesion of T. ferrooxidans did not. T. ferrooxidans recognized the reduced iron in minerals and selectively adhered to pyrite and chalcopyrite by a strong interaction other than the physical interaction.

An on-line method to detect incipient failure of turn insulation in random-wound motors

Induction motors used in various mining industry applications fail frequently because they are subjected to severe operating conditions. Periodic test procedures are inappropriate for many installations and the cramped and hazardous mining environment makes unscheduled motor replacements difficult and time-consuming to perform. An online detector of insulation degradation is proposed and demonstrated analytically and experimentally. This detector, termed the effective negative-sequence impedance, is computed from the voltage and current phasors at the motor terminals. It can be used frequently, even continuously, and does not interfere with normal motor operation. With this detector, motor replacements can be scheduled, thereby reducing production downtime associated with emergency maintenance actions.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>