Open Access. Powered by Scholars. Published by Universities.®

Mining Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

Discipline
Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 3721 - 3750 of 4588

Full-Text Articles in Mining Engineering

Novel Approach To The Energy Analysis Of Mine Cooling Strategies, C. T. Twort, I. S. Lowndes, S. J. Pickering Jun 1999

Novel Approach To The Energy Analysis Of Mine Cooling Strategies, C. T. Twort, I. S. Lowndes, S. J. Pickering

U.S. Mine Ventilation Symposium

The extraction of minerals and coal at increasing depth, employing higher-powered, mechanized machinery to increase production levels imposes an increased burden on the ability to maintain an acceptable mine climate. Any deterioration in the mine climate within working zones may adversely affect the health and safety of the workforce. The combination of the optimal design of the mine system layout, together with the selective application of suitable ventilation and cooling systems, may be used to control the climate within working zones. The adoption of mechanical cooling within mines is an expensive process in terms of both capital and operating costs. …

Go to article

Performance Assessment Of A Multi-Stage Cooling System At San Manuel Mine, Kuda R. Mutama Jun 1999

Performance Assessment Of A Multi-Stage Cooling System At San Manuel Mine, Kuda R. Mutama

U.S. Mine Ventilation Symposium

This paper describes the mine ventilation cooling system at San Manuel Mine, which has evolved as new deeper and hotter working levels were added to the mine, between 1979 -1997. The expansion philosophy was based on utilizing existing facilities, providing lower capital cost and operational convenience. The cooling system is comprised of three surface chillers of 10.55 Megawatts (3,000 tons) total cooling capacity. Cooling towers, also located on surface, ultimately reject all the heat from underground system. The chilled water is pumped to a shell and tube heat exchanger station located 915 metres underground in a high pressure circulating water …

Go to article

Mathematical Description Of Air Cooling Using A Mining Diaphragm Cooler Taking Into Consideration The Condensation Of Water Vapour, Waclaw Dziunyński, Stanislaw Nawrat, Bernard Nowak, Janusz Roszkowski Jun 1999

Mathematical Description Of Air Cooling Using A Mining Diaphragm Cooler Taking Into Consideration The Condensation Of Water Vapour, Waclaw Dziunyński, Stanislaw Nawrat, Bernard Nowak, Janusz Roszkowski

U.S. Mine Ventilation Symposium

Taking into consideration the possibility of condensation of water vapour contained in air which flows through a diaphragm cooler, a mathematical model of space-time changes in air temperature, humidity, and also in the temperature of the heat exchanger and the cooling water in the cooler in question was created. In the mathematical description of air-cooling using the above-mentioned cooler two zones was identified. The first concerns the dry cooling of air, while within the second, the process of outdropping of water contained in the cooled air. Each of these zones has been described by applying a system of three partial …

Go to article

Rapid Extinguishing Of Sponcom Fires In Underground Mines, Zygmunt Kajdasz, George Zieba Jun 1999

Rapid Extinguishing Of Sponcom Fires In Underground Mines, Zygmunt Kajdasz, George Zieba

U.S. Mine Ventilation Symposium

The main purpose presented in this paper is to present active and passive methods to fight a sponcom fire. The active method uses an inert gas generator called the GAG while the passive method is through the use of ventilation software. In most sponcom situations a combination of these two methods results in rapid extinguishing of the overheated areas. The presented software allows for accurate and "real time" analysis of the ventilation network. Application of the GAG has been proven on many occasions as an effective means of large volumes of mine atmosphere.

Go to article

Recovery Of Minerales Monclova Minas V, Patrick Graham, William Marston, Donald Mitchell, John W. Stevenson, David Sullivan Jun 1999

Recovery Of Minerales Monclova Minas V, Patrick Graham, William Marston, Donald Mitchell, John W. Stevenson, David Sullivan

U.S. Mine Ventilation Symposium

Methane issuing from a roof-bolt hole ignited when the hot bit was withdrawn. Similar ignitions have occurred in other mines. This one differed in that flames spread quickly, coal was ignited, and, after three futile hours of applying inadequate water and extinguishing agents, the mine was sealed. Fires are fuel and ventilation controlled. In this mine there was an abundance of methane, coal, and wood lagging. Recovery of the mine, therefore, depended on successful control of its ventilation. The recovery was done without anyone suffering a scratch; a remarkable feat considering the abnormal methane outflows and concentrations, the continuing evidence …

Go to article

Installation Of Two Main Fans At P.T. Freeport Indonesia's Underground Facilities, Felipe Calizaya, A. Mulyadi Jun 1999

Installation Of Two Main Fans At P.T. Freeport Indonesia's Underground Facilities, Felipe Calizaya, A. Mulyadi

U.S. Mine Ventilation Symposium

This study summarizes the technical aspects related to the installation of two main fans at P.T. Freeport Indonesia: one centrifugal and one axial. The fans were installed to increase the exhaust capacity of two vent systems. The 450 kW fan has been installed on surface to support an underground mine expansion project. The installation included the construction of a transition chamber, a retention wall, and the fan installation and commissioning. The 250 kW fan has been installed in an incline to increase the exhaust capacity of an ore pass ventilation system. The study presents the installation details from ground excavation …

Go to article

Axial Flow Fan Use At San Manuel Mine, Kuda R. Mutama, Dave P. Pelletier Jun 1999

Axial Flow Fan Use At San Manuel Mine, Kuda R. Mutama, Dave P. Pelletier

U.S. Mine Ventilation Symposium

A case study is presented for the use of multiple axial flow main fans as the principle source of the primary mine ventilation system for a large multi level mine. Formerly owned by Magma Copper, BHP Copper Inc.'s San Manuel Mine is a large underground block caving copper mine which started producing copper in 1955. The San Manuel Mine produces over 50,000 tons per day sulfide copper ore. The total airflow into this mine is approximately 800 m3/s (1,600,000 cfm). Providing adequate ventilation has been a very challenging experience as new, deeper levels are developed. BHP relies on …

Go to article

Deployment Of Self-Contained Self Rescuers In Australian Coal Mines, Najdat I. Aziz, Ernest Y. Baafi, Paul Mackenzie-Wood Jun 1999

Deployment Of Self-Contained Self Rescuers In Australian Coal Mines, Najdat I. Aziz, Ernest Y. Baafi, Paul Mackenzie-Wood

U.S. Mine Ventilation Symposium

In view of the recent mine disasters in the Australian coal mines, there has been a need to develop strategies to introduce SCSRs into coal mines to replace the approved filter self rescuers. A study was undertaken to evaluate the performances of the units in the normal Australian underground coal mine conditions. The study involved a laboratory and field trials at four underground coal mines using a total of 37 volunteers. These volunteers walked along the escape route at their respective mines on the first day carrying the SCSRs on their belts. The walk was repeated on a second day …

Go to article

Mine Safety In Chinese Coal Mines: Today And Tomorrow, Xintan Chang, Yunxiu Sai Jun 1999

Mine Safety In Chinese Coal Mines: Today And Tomorrow, Xintan Chang, Yunxiu Sai

U.S. Mine Ventilation Symposium

As a result of governmental agency restructuring, China's coal industry has been going through evolutionary changes as well in recent years. This paper discusses the various structural changes within the former Ministry of Coal Industry (MOCI) that occurred recently and its impact on coal production, health and safety regulation enforcement, safety training, and higher education.

Go to article

Equivalent Roughness And Its Application In Calculating Friction Drag Of Mine Roadway, Yan Zhou, Xingshen Wang Jun 1999

Equivalent Roughness And Its Application In Calculating Friction Drag Of Mine Roadway, Yan Zhou, Xingshen Wang

U.S. Mine Ventilation Symposium

Some roadways, which do not behave as "wholly rough pipe" as we expected, will have different impact on airflow in a mine ventilation network because of the low Reynolds numbers. For a "non-Wholly-rough" roadway, its resistance factor (R) or the friction factor (¦) is not only dependent upon the relative roughness but also dependent upon the Reynolds number, which varies directly as the flow rate. In this case, R or ¦ is no longer a constant independent of flow rate. Thus, in order to correctly calculate the friction drag of the same roadway for different flow rates, ¦ must be …

Go to article

Practical Values Of Friction Factors, Brian S. Prosser, Keith G. Wallace Jun 1999

Practical Values Of Friction Factors, Brian S. Prosser, Keith G. Wallace

U.S. Mine Ventilation Symposium

Over the past fifteen years, engineers from Mine Ventilation Services, Inc. (MVS) have measured numerous friction factors at many different types of mining operations. The results of these measurements indicate that standardized friction factors referenced in most ventilation textbooks are greater than those measured in the field for similar airway support systems. Many referenced friction factors are still based on G. E. McElroy's classic paper "Engineering Factors in the Ventilation of Metal Mines" published in 1935. Most mechanized mines now incorporate airways that are larger, have more advanced support systems, and more uniform openings. This paper describes the measurement techniques …

Go to article

Direct And Inverse Problem Of Diffusion With Simultaneous Linear Accumulation, Petko Ivanov Lalov Jun 1999

Direct And Inverse Problem Of Diffusion With Simultaneous Linear Accumulation, Petko Ivanov Lalov

U.S. Mine Ventilation Symposium

Mine working contamination occurs when diffusion in a constant velocity medium is accompanied by a process of absorption and accumulation of the diffunding medium, as described by the generalized convective diffusion equation proposed by J.L. Litwiniszyn. The first part of this article discusses the problem of finding a solution to the integro-differential equation under study for defined initial and boundary conditions corresponding to working with a finite length (direct problem). The second part solves the problem of determining the coefficients of this equation by using the results of measurements of the contaminant concentration by sensors positioned along the working (inverse …

Go to article

Modelling Of The Occurrence Of Hydrogen Sulphide In Coal Seams, A. D. Stewart Gillies, Mehmet S. Kizil, Hsin Wei Wu, Timothy J. M. Harvey Jun 1999

Modelling Of The Occurrence Of Hydrogen Sulphide In Coal Seams, A. D. Stewart Gillies, Mehmet S. Kizil, Hsin Wei Wu, Timothy J. M. Harvey

U.S. Mine Ventilation Symposium

Hydrogen Sulphide (H2S) has been encountered within a number of Bowen Basin collieries, Central Queensland, Australia. High concentration occurrence during mining of a longwall panel raises a number of potential problems, which demand greater understanding to allow efficient mining while maintaining safe and healthy environmental conditions. Longwall panels at Mine A and Mine B have recently mined through H2S zones. The high H2S zone mined through at Mine A was wide and covering the whole length of the face comparing to the narrow H2S zone which was cutting the panel at 45° …

Go to article

Management Of The Mining Industry/Research Organization Interface, Brad John, Jeneth M. Spiliopoulos, Judy Beazley, Timothy J. M. Harvey, A. D. Stewart Gillies Jun 1999

Management Of The Mining Industry/Research Organization Interface, Brad John, Jeneth M. Spiliopoulos, Judy Beazley, Timothy J. M. Harvey, A. D. Stewart Gillies

U.S. Mine Ventilation Symposium

The purpose of a consultancy undertaken to assess management processes in research projects to improve communication between research organisations and the mining industry through the development of an improved mode of operation and customer interface is discussed. The consultancy was conducted using the Nadler and Tushman Congruency Model of Organizational Behaviour to assess components of a projects inputs, transformation process and outputs for their degree of congruence or 'fit'. As an example the University of Queensland (UQ) managed ACARP Project 'Maximising Coal Production in the Presence of Hydrogen Sulphide (H2S) Seam Gas' was used for illustration. An action …

Go to article

An Investigation Of Longwall Gob Gas Behavior And Control Methods, Steven J. Schatzel, William P. Diamond, Fred Garcia, John C. Lascola, Frank E. Mccall, Paul W. Jeran, Thomas P. Mucho Jun 1999

An Investigation Of Longwall Gob Gas Behavior And Control Methods, Steven J. Schatzel, William P. Diamond, Fred Garcia, John C. Lascola, Frank E. Mccall, Paul W. Jeran, Thomas P. Mucho

U.S. Mine Ventilation Symposium

The National Institute for Occupational Safety and Health (NIOSH) has initiated the use of a tracer gas in field studies to characterize geologic and mining factors influencing the migration of longwall gob gas. Three studies have been conducted using sulfur hexafluoride (SF6) at a coal mine in the Northern Appalachian Basin operating in the Pittsburgh Coalbed. Eight underground tracer gas releases and one gob gas venthole release are summarized. The results indicate that the gas flow in the bleeder network and in the interior regions of longwall panel gobs do not strongly interact and that the negative pressure …

Go to article

Flammable Gas Emissions In South African Gold And Platinum Mines Review Of Incidents And Accidents, A. P. Cook, C. F. Meyer, K. Balt Jun 1999

Flammable Gas Emissions In South African Gold And Platinum Mines Review Of Incidents And Accidents, A. P. Cook, C. F. Meyer, K. Balt

U.S. Mine Ventilation Symposium

Flammable gas emissions are relatively common and widespread across the South African gold and platinum mines, but a general lack of awareness has lead to an increase in flammable gas related accidents and fatalities over the last ten years. The gas is usually a mixture of hydrocarbons C1 to C4 with hydrogen, each in varying quantities, with methane and hydrogen predominant. The three most common causes leading to gas accidents are changes to the ventilation, lack of testing for gas, and contraband, with gas ignitions caused by contraband and illegal tampering with caplamps. Development work accounts for 70 percent of …

Go to article

Gob Well Flaring: Design And Impact Analysis, Daniel J. Brunner, Karl Schultz Jun 1999

Gob Well Flaring: Design And Impact Analysis, Daniel J. Brunner, Karl Schultz

U.S. Mine Ventilation Symposium

Currently, over 30 U.S. Coal Mining operations employ a system of degasification to assist in reducing the emission of methane into their mine ventilation systems. All of these mines use vertical gob wells. This is an effective gob de gasification technique for U.S. longwall coal mining operations, particularly when prime movers apply suction to the wellheads (active gas extraction). In most cases mine operators discharge gas recovered from gob wells directly to the atmosphere. This practice poses safety and environmental concerns, and wastes a potential resource. In the U.S. there are no standards for equipping actively extracted or passive gob …

Go to article

Design Of Methane Drainage Systems To Reduce Mine Ventilation Requirements, Michael D. Zuber, Charles M. Boyer Ii, Denise L. Delozier Jun 1999

Design Of Methane Drainage Systems To Reduce Mine Ventilation Requirements, Michael D. Zuber, Charles M. Boyer Ii, Denise L. Delozier

U.S. Mine Ventilation Symposium

There are numerous proven methods to drain methane from coal seams in coal mines. These systems include vertical wells drilled ahead of mining, horizontal boreholes, gob wells, and others. However, these drainage systems are not typically applied properly to optimize gas recovery and minimize the cost of ventilation to the mine. This lack of optimization generally occurs due to the large up-front costs associated with the drainage systems and the lack of knowledge regarding the drainage technology. This results in the mine having a "reactive" response to methane drainage issues as opposed to a "pro-active" plan for handling methane drainage. …

Go to article

Methane Ignitions On Roof Bolters In Underground Coal Mines, John E. Urosek, William J. Francart Jun 1999

Methane Ignitions On Roof Bolters In Underground Coal Mines, John E. Urosek, William J. Francart

U.S. Mine Ventilation Symposium

Although not as frequent in nature as ignitions on continuous miner or longwall faces, ignitions of methane on roof bolters have caused serious injuries to underground coal miners. After reviewing the accident reports for all roof bolter ignitions from 1981 to 1998, a summary of the forty-one accidents has been developed. Of interest in the database is the ignition source, method of face ventilation, local velocity, methane liberation, size of the methane body ignited, and the duration of the flame. Three example ignitions are included.

Go to article

A Proposed New Method To Determine The Effectiveness Of In-Heading Methane Control, F. J. Van Zyl Jun 1999

A Proposed New Method To Determine The Effectiveness Of In-Heading Methane Control, F. J. Van Zyl

U.S. Mine Ventilation Symposium

Various methods have been derived to determine the effectiveness with which ventilation systems clears headings of methane in a bord-and-pillar sections. A problem with applying these methods in underground sections is that the either require the face-area air quantity to be measured, which is virtually impossible in South African collieries, or they were developed for test galleries, making it difficult to use in production sections. Taking this into consideration the methane safety index (MSI) method was developed. The method utilizes methane data recorded around an active continuous miner (CM) and an activity log of cm operations to quantitatively assess methane …

Go to article

Evaluation Of A Continuous Miner Half-Curtain Dust Control System In A South African Underground Coal Mine, Bharath K. Belle, J. J. L. Du Plessis Jun 1999

Evaluation Of A Continuous Miner Half-Curtain Dust Control System In A South African Underground Coal Mine, Bharath K. Belle, J. J. L. Du Plessis

U.S. Mine Ventilation Symposium

The issues of public health and safety in the mining industry have been dealt with around the world through the intervention of governments. In 1997 the South African Department of Minerals and Energy (DME) sent out a directive to reduce the dust concentration level to /m3 at the operator's position for the sampling period. The reasons for the difficulty with compliance are: long headings up to 35m, inherently high dust generation rates of coal, and the increased use of highly mechanized equipment. A project was formulated under SIMRAC auspices with the title of "Underground Mechanical Miner Environmental Control" to …

Go to article

Laboratory Evaluation Of Pressure Differential Based Respirable Dust Detector Tube, Jon C. Volkwein, April L. Schoeneman, Steven J. Page Jun 1999

Laboratory Evaluation Of Pressure Differential Based Respirable Dust Detector Tube, Jon C. Volkwein, April L. Schoeneman, Steven J. Page

U.S. Mine Ventilation Symposium

A new type of respirable dust sampler was developed and compared side by side to personal gravimetric samplers in the laboratory. The new sampler correlates filter back pressure with mass accumulation to provide mid-shift and end-of-shift determinations of cumulative exposure. The sampler uses a small low flow rate pump to draw dust through a small detector tube that contains a porous urethane foam respirable classification section and glass fiber filter that collects respirable dust. Six different coal dusts were aerosolized in a laboratory dust chamber and a total of 118 triplicate observations were obtained. For individual coal types, the correlation …

Go to article

The Effects Of A Diesel Particulate Filter And Fuel Borne Catalyst On Engine Emissions, Mahé Gangal, Thierry Leprince, John Muter, Brent Rubeli Jun 1999

The Effects Of A Diesel Particulate Filter And Fuel Borne Catalyst On Engine Emissions, Mahé Gangal, Thierry Leprince, John Muter, Brent Rubeli

U.S. Mine Ventilation Symposium

CANMET has been involved in an industry-government program to assess the quality of mine air and to improve the working environment. One aspect of the program is to reduce diesel particulate matter (DPM) generated by heavy-duty diesel vehicles having low exhaust temperature duty cycles. The low exhaust gas temperatures that are common in modem engines lead to insufficient regeneration of diesel particulate filters (DPF). A study was undertaken in partnership with DCL International to examine additive assisted regeneration. This study uses a cerium based fuel-borne catalyst to complete the regeneration of a DPF. Regeneration of a DPF occurs when the …

Go to article

An Integrated Approach To Control Diesel Particulate Matter In Underground Coal Mines, Pramod C. Thakur, Larry D. Patts Jun 1999

An Integrated Approach To Control Diesel Particulate Matter In Underground Coal Mines, Pramod C. Thakur, Larry D. Patts

U.S. Mine Ventilation Symposium

Diesel engines were introduced in European, Asian, and Australian coal mines nearly fifty years ago and more recently in U.S. coal mines. Their use minimizes the risks of mine fires and gas explosions associated with trolley wire haulage. While there is no epidemiological evidence that properly diluted diesel exhaust creates any health hazard, some concern persists about the long-term effects of inhaling diesel particulate matter. Existing control technology has been able to dilute all gaseous components of diesel exhaust to safe levels. Because there is no medically established threshold limit value for diesel particulate matter in U.S. coal mines, it …

Go to article

Mine Fire Detection In The Presence Of Diesel Emissions, J. C. Edwards, R. A. Franks, G. F. Friel, C. P. Lazzara, J. J. Opferman Jun 1999

Mine Fire Detection In The Presence Of Diesel Emissions, J. C. Edwards, R. A. Franks, G. F. Friel, C. P. Lazzara, J. J. Opferman

U.S. Mine Ventilation Symposium

A series of four coal combustion experiments was conducted at the National Institute for Occupational Safety and Health's (NIOSH) Pittsburgh Research Laboratory (PRL) in the Safety Research Coal Mine (SRCM) to evaluate the response of fire sensors to a small 0.61 m square smoldering coal fire which transitions to flaming combustion in the presence of diesel emissions. An optical path smoke sensor alarmed earlier than a point type diffusion mode ionization smoke sensor, which alarmed prior to a co alert value of 5 PPM above ambient. The presence of steady state diesel emissions resulted in a decrease in the optical …

Go to article

Computer Simulation Of Climatic Conditions For Underground Automated Mines For Standard And Reduced Airflow Requirements, Julian Partyka, Stephen Hardcastle, Charles Kocsis Jun 1999

Computer Simulation Of Climatic Conditions For Underground Automated Mines For Standard And Reduced Airflow Requirements, Julian Partyka, Stephen Hardcastle, Charles Kocsis

U.S. Mine Ventilation Symposium

This study demonstrates the importance of ventilation in an automated mine through climatic simulations. These have been performed on workings located at depths of 1000 m to 3000 m below surface in an underground metal mine. Each active working area employs either an electric or a diesel piece of equipment that has a full load power output of 100 kW to 200 kW. The airflows considered in the mining areas were standard full-flow conditions, i.e. 100% (6.5 m3/100 kW), and 125%, 75%, and 50% of full-flow. The analyses show, for instance, that a 100 kW electric machine can increase the …

Go to article

Non-Destructive Field Measurements Of Rock Temperature And Heat Flow In A Hot Mine, Vilen P. Chernyak, Eduard N. Malashenko, Pierre Mousset-Jones Jun 1999

Non-Destructive Field Measurements Of Rock Temperature And Heat Flow In A Hot Mine, Vilen P. Chernyak, Eduard N. Malashenko, Pierre Mousset-Jones

U.S. Mine Ventilation Symposium

A number of thermophysical measurements were carried out at the Meikle mine in Nevada in order to obtain new data concerning heat flows and wall temperatures in a hot mine. This was necessary to verify known methods of heat flow calculation and compare experimental with theoretical results. The Meikle mine was chosen because it is operated in an area of high rock temperature caused by the hydrothermal nature of the deposit and the presence of water at 60°C. The airflow rates in some of the inactive areas and the predicted background rock temperature at the mine are similar to those …

Go to article

Author's Index, Multiple Authors Jun 1999

Author's Index, Multiple Authors

U.S. Mine Ventilation Symposium

No abstract provided.

Go to article

Ventilation Network Optimization For Deep Mines, Ventzislav Bojilov, Mitko Hadjiev, Georgi Shoushoulov Jun 1999

Ventilation Network Optimization For Deep Mines, Ventzislav Bojilov, Mitko Hadjiev, Georgi Shoushoulov

U.S. Mine Ventilation Symposium

The development of underground mines in Bulgaria has reached depth limit. The conventional approach for engineering the mine ventilation is unsatisfactory under the existing level of concentration and intensification of mining work under the already complicated mining and geological conditions. This necessitates the optimization of ventilation networks for achieving the required efficiency and reliability. Direct measurements in mines has created an adequate numerical mine ventilation model. This model can optimize and forecast the future development of the mine ventilation system with the help of computer software. By means of the prepared nomograms the individual parameters of the ventilating flow are …

Go to article

Axial Fan Monitoring By Pressure Transients Close To The Blades, A Preliminary Study, Ian Loomis, Shaun Ramsay Jun 1999

Axial Fan Monitoring By Pressure Transients Close To The Blades, A Preliminary Study, Ian Loomis, Shaun Ramsay

U.S. Mine Ventilation Symposium

As the axial fan blades move within the fan case pressure transients are developed, which can be measured and qualified by a fixed point monitor. The nature of the pressure transient pattern observed close to the fan blade varies with the location on the fan performance curve. Measurement of the pressure fluctuation around the fan blade ring reveals the minute variation in pressure associated with the movement of the air within the fan. Such observations could be the basis for an on-line fan monitoring system based on the acoustic emissions from the fan blade. This paper describes a preliminary study …

Go to article

First Prev Next Last