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By J. J. Fallon

Las Vegas is a place of many distractions. It is difficult for one to apply himself to sophisticated technical matters in the midst of gambling, liquor, scantily clad young ladies and the top entertainment available in the United States. But, I know that the men and women of SME are made of stronger stuff and will not be tempted by these things.

Jan 1, 1989

By Bernie W. Martin

The East Side Access (ESA) project is the largest commuter railroad project ever undertaken in the United States. The purpose of the ESA project is to bring commuters from Long Island into Grand Central Terminal. The program is estimated to cost $4.3billion. The purpose of this paper is to describe the key design elements for the Queens segment, ?re life safety, ventilation and changes to the proposed contract delivery method.

Jan 1, 2003

By J. J. Webb

At Kerr-McGee's Galatia Mine in southern Illinois, the need for safe and efficient longwall moves prompted a detailed planning effort. Galatia Mine operates two longwalls on separate coal seams with different geologic conditions. An overview of the longwall move planning as related to manpower training, roof control, ventilation, transportation, equipment recovery and setup will be discussed. The impressive safety record achieved during each of the longwall moves at Galatia Mine verifies that health and safety planning does play a major role.

Jan 1, 1994

By Jun Han

Coal has been mined in the Kailuan mining area for more than 130 years. The remaining reserves consist of, in large part, coals that would have been considered economically unminable or technically not feasible by the previous generations. Some of the current operations have to resort to overmining because the lower seams had been extracted in the past. This paper deals with the feasibility and proper layout of mining roadways of overmining carried out in the No. 5 seam of Qianjiaying coal mine of Kailuan mining area using numerical and physical simulation. FLAC2D was used to investigate the characteristics of stress and displacement in the overburden after extraction of the lower seams. It also analyzed the proper layouts of gateroads in the upper seams, i.e. locating them in the stress-relief zone of the gob so that their stability can be easily maintained. In addition, a two-dimensional physical model was constructed for investigation of damages to the upper seams due to mining of the lower seams. Finally, based on the results of investigations, proper gateroads layout was designed and successful extraction was implemented for panel 1357 in the No.5 seam.

Jan 1, 2009

The US economy grew at a rate of 4% in 1994 and the gross domestic product rose to $6.74 trillion. With 261 million people - 605,000 in mining, including petroleum -the United States has l 10 million dwelling units and 200 million licensed motor vehicles. New private housing units authorized in 1994 rose 14% to 1.4 million units. New car production rose 11 % to 6.6 million units, while truck and bus production rose 30% to 5.2 million units. The inflation rate was less than 3% and the prime rate of interest averaged 7.15%. The producer price index (1982 = 100) for fuels and related products and power was down 4% to 78, while metals and metal products rose 5% to 125. Chemicals and allied products rose 3% to 132, and non-metallic mineral products rose 3% to 124. The merchandise trade deficit rose 25% to $166 billion. Disorder in the former Soviet Union led to substantial dumping of mineral materials. With vast mineral resources, the former Soviet Union land area totaled 22.4 million km2 (8.6 million sq miles). In comparison, the North Ameri¬can Free Trade Agreement (NAFTA) area (United States, Canada and Mexico) totals 21.4 million km2 (8.3 million sq miles).

Jan 1, 1995

By C. G. Anderson

Historically, the treatment of orebodies for recovery of valuable constituents presents many processing challenges. In a time of heightened environmental awareness, the constraints placed on processing complex orebodies are becoming more and more pronounced. As such, established technologies are limited in their ability to fill the needs of these emerging sources of raw materials. A prime example of this is in processing PGMs from primary sources. Normally, this type of material is found in a nickel-copper-iron sulfide matrix. Typically, these materials are processed by established pyrometallurgical means. However, other options should be considered. Hydrometallurgical processes are available which offer advantages over pyrometallurgical methods. One of these is the nitrogen species catalyzed sulfuric acid pressure leach used industrially by Sunshine Mining and Refining Company. In 1990, laboratory work was undertaken in cooperation with Stillwater Mining Company to test PGM matte materials from the Columbus, Montana smelter. The initial results were very positive, and they led to a design to recover PGMs in a high grade residue and to recover nickel and copper as valuable products. Handling the iron and other wastes in an environmentally safe manner was also successfully investigated.

Jan 1, 1995

By André Vien, Robert Edwards, Rob Perry

A metallurgical control application can only succeed if the system's lowest common denominator, its instrumentation and regulatory control is implemented and maintained correctly. This paper describes the basics of regulatory control implementation including some practical guidelines for instrumentation installation, operator interface design, loop tuning, and continuous loop performance analysis. Tuning and analysis techniques are illustrated by step-by-step industrial examples. A small investment in basic control pays dividends in better overall plant performance and provides a solid foundation for advanced control efforts such as expert systems.

Jan 1, 2000

Cost accounting information is used primarily for (1) planning, control, and performance evaluation; and (2) managerial decision-making. Incremental analysis is a tool for managerial decision-making. It is designed to estimate future financial performance, namely the benefits and costs associated with alternative courses of action. Decisions may be distinguished as pertaining to short-term or long-term activities. Long-term activities frequently focus on capacity decisions and the attendant capital budgeting processes used to quantify the financial effects of these decisions. Short-term decisions typically address short-range production quantity and pricing issues, outsourcing, selection of the optimal mix of products, inventory management, and the acceptance of special orders. This chapter addresses these short-term decisions.

Jan 1, 1999

By L. M. English

In the past 30 years, the research arena has changed significantly in all fields, mining included. The relative representation of the topics of research, how the research is performed, and who has performed the research have all changed significantly over these decades. Although there are a lot of subjective ideas concerning these changes, and there is a fair amount of anecdotal "analysis," there has been no actual study of these trends to verify the facts. The period studied is divided into six five-year periods for the purposes of comparison. Some of the trends analyzed are as follows: ? Co-authorship ? Research areas ? Research sponsors ? Cooperative efforts

Jan 1, 1995

By A. Haghighat, B. Lattimer

"Mine face ignition due to a high levels of methane is one of the most common fire incidents in underground coal mines. This work exams ignition scenarios in continuous miner headings. Depending on the magnitude of the ignition or resulting fire, the ventilation curtain in the continuous miner (CM) heading may be damaged or dislodged, affecting the ventilation into the area. A computational study was conducted to investigate the effects of different levels of damage to the ventilation curtain on the ventilation flow into the CM area. The computational fluid dynamics software Fire Dynamics Simulator (FDS), Version 6.0 was used to predict the conditions that develop due to a 200 kW fire in the coal mine face following a methane ignition with different levels of curtain damage. Smoke layer depth, temperatures and mass flow into the CM area were used to evaluate the impact of no damage to the curtain, partially dislodged curtain, and fully removed of the curtain. Partial removal of the curtain allowed more smoke to accumulate in the CM area and a reduction in ventilation into the CM area. With full removal of the curtain, the smoke accumulated through the entire depth of the CM area and flowed out the entrance to the CM area and the ventilation completely bypassed the region. INTRODUCTION Active working faces in underground coal mines are one the most hazardous locations in terms of fire events. According to Mine Safety and Health Administration (MSHA) data analysis, the highest number of non-fatal fire incidents was reported at mining faces, intersections and crosscut areas in comparison with other locations from 2000 to 2012. About 464 fires happened at active working faces from 2000 to 2012, most consisting of a methane ignition, in some cases followed by localized fire. These are high risk incidents due to the potential to raise float dust and damage ventilation systems, particularly auxiliary systems such as curtain or tubing. Depending on the magnitude of the ignition or fire, the ventilation curtain in the continuous miner (CM) area may be damaged or dislodged, affecting the ventilation into the area. Five computational fluid dynamics (CFD) scenarios were considered to investigate the smoke layer depth, temperature, visibility, mass flow rate, and the behavior of airflow in an entry with a continuous miner (CM) located in it. The state of the auxiliary ventilation was varied based on the assumption that as an ignition increases it magnitude it will affect ventilation curtain proportionally. Visibility and temperature along the height of the entry at different sections were investigated and the interface height at each section was determined. Also, the fresh air height was studied for tenability analysis in future. FDS, Version 6.0 was used to predict the conditions that develop due to a 200 kW fire on the coal mine face following a methane ignition with different levels of curtain damage. Smoke view software was used as the post processor to visualize and analyze methane fire behavior at the face. Most entry fires are reported as fuel-controlled fires as they are rarely restricted to air access (Ingason et al, 2014). The working face fire in the following models was assumed to be a fuel-controlled fire."

Jan 1, 2016

By Frank R. (Original by) Barnako

Coal mining historically has been a hazardous occupation but, in recent years, tremendous progress has been made in reducing accidental coal mine deaths and injuries. The purpose of this chapter is to discuss the basic principles of accident prevention as they are related to coal mining. Accident prevention fundamentals are no different for coal mining than for any other type of work. The fundamentals apply to all industries. Construction workers may be struck by falling tools and materials, and miners may be struck by falling slate and coal. Sailors may be trapped by shipboard fires, and miners may be trapped by mine fires. Railroad brakemen may lose hands and fingers positioning couplers, and miners may lose hands and fingers positioning couplers. Many other examples could be cited, but the point is that accidents that happen in coal mines are basically similar to accidents that happen in other industries. Thus, the basic principles for preventing accidents apply in coal mining as they do in any other type of work.

Jan 1, 1981

By I. M. Konduri

Theoretical investigation and laboratory experimentation have shown a great potential for jet fan ventilation in mines. Jet fans, also called induction fans due to the induction effect of the fluid jet to ventilate headings, may have particular application in remote-controlled production operations. This paper summarizes ongoing research using a scaled laboratory model. The model uses water as a fluid medium and simulates a typical 25m long heading of 1.5mx6m cross-section. The effects of various nozzle positions and designs have been investigated by using still photography as a tool for flow visualization. It is also found that the use of jets in combination with line curtains has enhanced the overall ventilating effect in the model entry.

Jan 1, 1996

By O. Alvarez-Campos

Two porphyry copper orebodies, the North and Central MM orebodies, have been found through regional and structural geologic works, about 5 Km south of Chuquicamata, under a gravel bed of approximately 100 m and in the west side of the West Fissure. The mineralization is emplaced in a coarse granodioritic porphyry, predominantly with sericitic alteration. In the North MM ore-body, with 200 million metric tons of 1.0% Cu, the mineralization is mainly chalcopyrite, bornite, digenite and molibdenite. In the central MM orebody, with 700 million metric tons of 1.3% Cu, there are large veins of enargite, chalcocite and bornite, the last one increasing in depth, separated by chalcopyrite and pyrite zones; in these veins there are interesting gold and silver values. Both orebodies have an upper enrichment of chalcocite and covellite, with pyrite envelope. According with these characteristics, the MM orebodies could he the upper part, with sericitic alteration, of the Chuquicamata porphyry copper system, displaced by the West Fissure system movements, but we couldn't eliminate the possibility that MM can be a new orebody, different of Chuquicamata.

Jan 1, 1993

By Christophe Bragard, Jason Choi, William H. Hansmire

This case history provides a physical benchmark of tunneling technology progress comparing an old hand-mined tunnel to a modern 20-ft-diameter EPB TBM that mined in the same ground. This rare opportunity to see how tunnels were constructed many years ago occurred when an old 10-ft-diameter storm drain tunnel in the way of os Angeles subway construction was demolished and replaced with obas berglass pipe. Steel rib and lagging initial support was exposed showing solid-sawn 2" × 12" × 48" redwood lagging. This paper documents the as-built old tunnel, how it was successfully replaced, and some lessons learned.

Jun 23, 2024

By John S. Lagarias

When ore bodies are faulted or mill feed turns refractory, mining managers and engineers act vigorously to convert imminent failure into eventual success. The recent proliferation of onerous "environmental" regulations and restraints is likewise a threat to successful mining enterprise, in some ways more insidious and dangerous than the problems presented by natural obstacles. The regulatory burden has become so heavy that a pall of pessimism covers much of the mining enterprise. In this paper we frankly recommend a Pollyanna approach, making not just "the best of it" but directing the whole environmental process: first, to improve our planning, engineering, and operating procedures; and, second, to demonstrate the need for modification of laws and regulations which are intolerably burden-some to both the mining industry and the public. It is customary for government officials and environmentalists to point out how great are the new environmental regulations and how successfully these have improved the natural environment in particular and the quality of life in general.

Jan 1, 1978

By Neil Hepworth

Neves Corvo Mine employs four mining and four backfill methods, including paste fill. The paper shows how the strength requirement for backfill in primary stopes was calculated and the relationship between laboratory strength and in situ strength requirement. The liquefaction of paste in secondary stopes is discussed with methods to determine the liquefaction potential. It was found from laboratory tests and the preliminary results of the underground trial, that the liquefaction potential of the paste is low at 2% and is high at 0.5% cement. The results to date are inconclusive regarding 1% cement.

Jan 1, 2001

By J. E. House

Creative ideas and endeavors require imaginative and positive responses, if they are to be reduced to practices. This lecture will define the plurastic roles of various technical disciplines which were important in the development of the LIX reagents. Specific personalities, facts, and events will be used to trace the development from an idea, to the exciting acceptance and practice of the technology. An objective analysis of the entire LIX reagent development, spanning twenty-five years experience of the author, will be given, these will be used as a basis for critical examination of how the various technical disciplines could improve their effectiveness in advancing future technologies.

Jan 1, 1990

By Derek M. Hutchinson, Don Zeni

The construction of shafts by blind drilling has been made cost effective by advances in technology and experience. The techniques of blind shaft drilling are discussed and a brief history presented. A recent use of blind shaft drilling to access a small gold ore body in Australia is described. Finally, the most recent developments in drilling machinery are reviewed together with possible applications in new and existing mines.

Jan 1, 1987

By Richard H. Sailors

Data from full scale marked ball tests are used to demonstrate the effects of abrasion, corrosion, and impact on overall wear rate. The predominate wear mechanism need be identified before the optimum alloy can be chosen for the grinding media. Use of high chromium grinding media often results in increased mill efficiency due to shape retention. Thus, a benefit from energy savings can result as well as a reduction in wear rate. Converting from steel to east high chromium grinding media requires close association and cooperation between producer and consumer in order to properly conduct these studies.

Jan 1, 1990

By Y. Zimmels, C. Feldman

Closed-circuit grinding processes are considered in the context of a reactor-separator circuit that involves multifraction streams and products. Because grinding circuits are low-efficiency, capital-intensive operations, modeling to maximize their economic return is appropriate. An attempt to develop and test such a model is presented in this work. The model relies on process simulation for both the mill and the separator, in conjunction with constraints imposed by product specifications. The grinding process was simulated using breakage functions, which provided complete data on the feed and product of the mill. A cyclone bank used as the separator was also simulated using known models. The overall process model provided a complete simulation of the multistream grinding and separation process. The process model was then incorporated into an economic model that predicts grinding cost, subject to process constraints, for a given set of operating variables. The model facilitates economic optimization of the grinding process as it relates to process variables and process hardware.

Jan 1, 1993