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The National Institute for Occupational Safety and Health (NIOSH) conducted a study to determine the effectiveness of a filtered air delivery system to reduce respirable dust exposure to roof bolter operators in underground coal mines. When performing roof bolting operations, roof bolter operators may experience exposure to high levels of respirable dust during a working shift, especially when working downwind of the continuous mining machine. While drilling and installing roof bolts, this filtered air system supplies a clean curtain of air over the roof bolter operator by means of a plenum mounted beneath the canopy. This experimentally designed air curtain, adapted for roof bolting machines used in this study, is based upon previous design prototypes, computational fluid dynamics (CFD) simulations, and trial-and-error testing. Both prototype and final designs were tested in the full-scale mining galleries at the Office of Mine Safety and Health Research (OMSHR) in Pittsburgh before being taken underground for field testing. Test results of the system in both laboratory and field studies show reductions in operator exposure to respirable dust when the operator is positioned directly under the protected zone of the canopy.

Jan 1, 2012

By D. M. A. Flight, P. M. Green, J. A. Plant, P. R. Simpson

Paper presented at Mineralisation in the Caledonides, the Mike Gallagher memorial meeting held in Edinburgh, 27-28 June 1996. The British Geological Survey's regional geochemical database is used to identify the patterns associated with the various mineral deposit types and to examine the extent to which their distribution reflects the presence of long-lived metallogenic provinces in the crust. Image analysis provides new insights into the setting of the mineralisation, geochemical constraints on tectonic models of Caledonide evolution and evidence for terrane amalgamation and large-scale processes. There is evidence that much of the mineralisation reflects the presence of long-lived provinces with a distinctive geochemistry reflecting their origins as zones of crustal extension. In the case of the Middle-Upper Dalradiam sedex deposits, the relationship between geochemistry and tectonic setting is direct. In other cases, rocks deposited in extensional zones appear to have acted as reservoirs of ore-forming elements which were further concentrated during later events

Jun 19, 1905

By James H. Aase

[This study provides data on the physical and hydrological makeup of the ,t hakes waterway system and forecasts quantities, traffic patterns, and ping cost of prospective bulk mineral commerce projected to be transported it. Factors affecting the shipping cost of iron ore, bituminous coal, imestone were quantified and integrated into a computer program that can d to estimate costs under varying sets of conditions. Combined ship of iron ore, bituminous coal, and limestone in 1995 were estimated at million tons. The cost of operating the U.S. vessel fleet for trans-ng an indicated 80 percent of this traffic tonnage was projected to be $163. 5 million.]

Jan 1, 1970

By Mark R. Svinkin

Construction vibrations may adversely affect surrounding buildings and their effects range from human discomfort and disturbance of sensitive devices to visible structural damage. There is no unique conclusion regarding the effect of construction vibrations at every site. Measurement is usually made to monitor vibrations and control them with the vibration thresholds for disturbance of sensitive objects as well as damage to structures. To prevent potential litigation and mitigate the vibration effects on sensitive devices, people and structures, it is necessary to manage and minimize vibration problems before the beginning of construction activities or installation of vibrating machine foundations, and during construction. Pre-construction damage survey and engineering vibration investigations, including the prediction of anticipating vibrations, have to be made at most construction sites in advance of construction activities. Vibration monitoring and control have to be provided during construction. The instrumentation feedback of vibration prediction, monitoring and control provide the basis for choice of measures to prevent or mitigate vibration problems and settlement damage hazards.

Jan 1, 2002

Experimental results are presented that test the hypothesis that the descaling behaviour of stainless steel slabs following reheating is controlled by interfacial roughening at the scale-steel interface. In this investigation, two stainless steels were considered: type 304 (austenitic, with 18% Cr and 8% Ni) and type 412 (ferritic/martensitic, with 11.6% Cr). It was found that the entanglement that arises at the scale-steel interface was in fact effective in maintaining scale-steel adhesion, under the mechanical descaling conditions used. In the case of type 304, descaling proceeded by fracture along chromite layers, which formed (by internal oxidation) on the austenite grain boundaries; for this steel, the extent of descaling depends most strongly on austenite grain structure, and not primarily on the conditions in the reheating furnace. In contrast, type 412 samples descaled only at the edge of the entangled zone, and showed a greater sensitivity to the reheating conditions; specifically, higher free oxygen in the reheating gas and longer reheating times were found to increase the residual scale thickness. Key words: stainless steel, reheating, scale, entanglement, descaling, fayalite, internal oxidation, grain structure, free oxygen.

Jan 1, 2003

By A. Jarosz

The surface manifestation of underground mining usually entails five distinct types of surface movements, which can affect or damage surface structures, facilities and renewable resources. These movements developing at the surface can be described by (Bell, 1975; Bhattacharya and Singh, 1984): - vertical displacement, i.e. subsidence, - horizontal displacements, - slope or tilt, i.e. the derivative of the vertical displacement with respect to the horizontal distance, - curvature, i.e. the second derivative of the vertical displacement with respect to the horizontal distance, and, - horizontal strain, i.e. the derivative of the horizontal displacement with respect to the horizontal distance.

Jan 1, 1986

By Charles B. Carpenter

The New Hope field was selected for study by; Bureau of lanes engineers because many problems met by, the operators during development and operation were unique to petroleum-engineering experience. Solving these problems is believed to have doubled the ultimate recovery of oil from the field. Since the discovery well was 'completed, in April 1943, an oil-productive area of 4,950 acres- has been delineated by the drilling of 64 wells, four of which were dry holes. Four oil-bearing reservoirs - the Bacon oolitic limestone, and the Hill, Pittsburg) and Elledge sandstones, all, in the Trinity group of the Lower Cretaceous series-- have been penetrated at depths ranging from 7,300 to 8,100 feet. Three of these reservoirs were found to be closed-type or solution gas-drive reservoirs, and one - the Hill - was an open-type or water-drive reservoir. During the course of the study, the Tide Water Associated, Oil Co. and -Seaboard al Co. of Delaware made available to the writers all well records, electric logs; and coring, production,, and pressure data. The ,writers performed Certain field and laboratory- tests on cores of ,the reservoir racks and' samples -of the reservoir Oils. Analyses of cores from the four reservoirs showed average .porosities ranging from 10 to 18 percent, average permeabilities of 17 to 297 millidarcys, and -average 'connate water contents ranging from 25.4 to 30.6 percent. Subsurface and recombined samples of reservoir oils indicated that the oils in the Bacon Hill, and Pittsburg reservoirs contained ,206 to 422 cubic feet of gas in solution per barrel initially, and that the, reservoir oils were undersaturated with gas. No samples' of oil from the Elledge reservoir were analyzed, and because of meager data this reservoir was not studied in detail. 4 The presence of free 'gas' or a' gas cap, however, indicated that the oil in the Elledge reservoir was saturated with gas. The rapid decline in pressures in- the' four reservoirs during the 'first year of operation alarmed the operators and provoked them to investigate the reservoir conditions to determine the cause.

Jan 1, 1949

By P. Wearden, K. Bryner, K. Vrana, V. Castranova, R. Dey, R. Reist, J. Blackford

"Summary: Fibroblast proliferation and enhancement of collagen synthesis are key steps in the development and progression of pulmonary fibrosis. The current investigation presents a fibroblast proliferation assay to detect the release of competence factors from pneumocytes. The specific objective of this study was to define cell culture conditions for fibroblasts that would allow selective detection of competence factors in test media. The results indicate the following: (a) fibroblasts should be cultured for 2 days in plasma-free medium rather than 2% plasma to assure complete quiescence; (b) 1% plasma was optimum for producing progression activity for the bioassay of a competence factor, while 0.5% plasma did not produce sufficient progression activity (yielding false negatives) and 2% plasma often contained significant competence activity (yielding false positives); and (c) fresh plasma should be used since the progression activity of plasma was adversely affected by freezing and thawing. Under these conditions, this bioassay can be employed with either rat or human lung fibroblasts to detect competence factors such as platelet-derived growth factor (PDGF), at levels as low as 25 ng/ml.Fibrotic lung disease, as a consequence of occupational exposure to silica dust. is characterized by the development of concentric hyalinized nodular lesions in the lung and the progressive loss of pulmonary diffusion capacity. Proliferation of pulmonary fibroblasts and enhanced synthesis of collagen by these pneumocytes have been shown to be key steps in the development of chronic silicosis ( 1 ). The regulation of lung fibroblast proliferation by cytokines released from alveolar macrophages may be an important pathogenetic mechanism in the development of the fibrotic process (2). Some cytokines stimulate fibroblast proliferation by activating specific phases of the cell cycle (3,4). In particular, platelet-derived growth factor (PDGF) promotes fibroblast proliferation by inducing the movement of quiescent (G0 ) cells into the G1 phase of the cell cycle (5). Insulin-like growth factor (IGF) and transforming growth factor-P (TGF-P). on the other hand, regulate the rate of transition of fibroblasts from G 1 into the S phase (5,6). These two classes of cytokines have been termed competence and progression factors, respectively. One approach used to examine the release of cytokines from macrophages is the fibroblast proliferation assay in which quiescent fibroblasts are exposed to culture supematants from macrophages exposed to various stimuli. In most of these assays, the supernatant contains fetal calf serum (FCS), which provides the competence factor(s) necessary to facilitate the proliferation of fibroblasts (7-9). Recently, a fibroblast proliferation assay using platelet-poor .plasma [lacking competence factor(s)] as a substitute for FCS bas been described (I 0, 11 ). In this assay, the release of a competence-inducing PDGF-like growth factor from rat and human macrophages can be distinguished from other cytokines that act as progression factors."

Mar 1, 1992

By Glenn L. Allen

The rapid rise of industrial Los Angeles to international prominence has been accompanied by the natural corollary - a record influx of population - together with greatly increased production and fabrication of steel and nonferrous and light metals; industrial mineral processing; and high consumption of fuel oil, gasoline, and chemicals. These have resulted in the release of hundreds of tons of metallurgical and mineral dusts, fumes, and gases into the atmosphere daily. Los Angeles County, intrinsically, is no worse than other industrial centers in respect to the generation of atmospheric contamination. It is, in fact, more fortunate in that no coal is used, and it has no great primary metallurgical industries comparable to those of Chicago and Pittsburgh. Meteorologic and topographic peculiarities of the area, however, which result in poor drainage of the polluted air away from the Los Angeles Basin, serve periodically to greatly increase the intensity and frequency of industrial smog visitations. This combination of intense industrialization, population influx, climate, and topography has made mandatory control of air pollution necessary. The nonferrous pyrometallurgical industry of Los Angeles has three rather unusual characteristics that contribute to its difficulties in developing suitable fume control: It consists of a multiplicity of relatively small establishments subject to wide Variations in products and operating schedules; operations are largely of the secondary or reclaiming nature and, therefore, often work dirty scrap metals; and, unfortunately, much of the industry is concentrated, to a considerable extent, near the center of the city. A difficulty inherent in most nonferrous foundries, including the many brass-works melting alloys containing zinc, is the high volatility of zinc and the extremely small mean particle size of the resulting zinc oxide fume.

Jan 1, 1952

By R Lewis

Drill hole magnetometric resistivity (DHMMR) is a relatively recent addition to the explorationistsÆ suite of techniques for finding further resources in the vicinity of a drill hole. The method relies on gathering of an applied current into zones which are less resistive than the country rocks and it was first applied to exploration programs looking for weakly conductive sulphides, such as, for example, carbonate-hosted zinc deposits. More recently, it has been applied to a wider range of deposit styles, including highly conductive nickel sulphides. It has been found that the technique is capable of not only detecting mineralisation not seen by conventional electromagnetic (EM) techniques, but it can detect at a greater distance. Also, whilst EM is superior at defining tabular-shaped conductors, DHMMR may be more effective at finding cigar shaped sulphides. This paper presents a number of examples illustrating these findings.

Jan 1, 2000

By Harold W. Lipper

BUREAU OF MINES helium plants produced a. record-breaking 477 million cubic feet of this essential element in 1959. The supply of helium was less than the demand before operations were resumed at the Navajo plant in July and begun Sit a. new plant at Keyes, Okla., in August. Helium was in abundant supply after August, and the informal allocation system which had been in use intermittently since 1955 was discontinued Delivery of 26 new tank cars in August and September increased the total in the tank-car pool to 163. Defense and space agencies and the Atomic Energy Commission continued to use more helium in their operations and research.

Jan 1, 1960

Development of a permanent human base on the Moon for exploration requires a self sustaining system. This entails production and processing of limited amounts of raw material on the Moon. Any mining and construction activities on the Moon can only be performed by a robust excavation machine that can excavate a variety of material from loose surface regolith to consolidated (frozen) regolith with embedded rocks in the mixture. Meanwhile, limited amount of information on lunar regolith is available to develop and optimize a machine for given lunar ground conditions. Therefore, any excavator designed for use on the lunar surface should have the ability to adapt to a wide range of operating conditions. A prototype cutterhead for the lunar excavator was built and tested at the Kennametal facility in Latrobe PA A. This paper discusses the results of initial material characterization as well as full scale tests of a prototype cutterhead inrelevent material. A brief review of anticipated production rates under various assumed ground conditions will also be presented.

Jan 1, 2009

By B E. McCarthy

Red Dome Mine was a highly complex gold copper operation developed over a number of phases between mid-1986 to October 1997. With only three years of production ahead at any time, a proactive practical approach to mine closure was necessary. In 1989 the Domains Concept to life-of-mine planning and mine closure was created as a response to the proposed changes to legislation.The Domains Concept, a relatively simple idea developed to integrate mine closure during production at Red Dome, has been broadly adopted by both government agencies and industry in the intervening 20 year period. Over time the author has observed that the concept has been poorly applied, misunderstood and in some cases even misrepresented. As a consequence, the potential opportunities from applying the concept, including the optimisation and minimisation of life-of-mine costs, mitigation of long-term financial liability exposures and building credibility with the general community, have been missed.This paper examines the many benefits, advantages, applications and perceived barriers to developing and integrating a fully costed life-of-mine plan. Integrating the Domains Concept early in the project, within the operational budgeting, allows the production of a meaningful and useful document, representative of a whole life-of-mine, cradle to grave, with measurable rehabilitation and closure outcomes when the concept is used to full effect.The Domains Concept serves to optimise cost-effective, whole of mine, life cycle planning which provides beneficial outcomes for the community, significantly mitigates legacy issues and contributes to the attainment of compliance and sustainability principle objectives.CITATION:McCarthy, B E, 2014. The domains concept – 20 years on retrospective, obstacles and opportunities for effective life-of-mine implementation, in Proceedings Life-of-Mine 2014 , pp 621–636 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By D. Randolph Berry

Foster-Miller Associates has developed a set of guidelines to permit hoist manufacturers, mine owners, and MESA mine inspectors to design, purchase, install or inspect a safe and effective Emergency Escape Hoist, as required by the Coal Mine Health and Safety act of 1969. A series of surveys were carried out to determine: 1. The attitudes and local needs of the MESA District Managers. 2. Current escape hoist installations. 3. Equipment available for future designs. 4. Foreign methods and equipment for mine rescue. From these survey studies, preliminary guideline objectives were developed.

Jan 1, 2012

By H. Boghosian

This paper presents the design and construction of a deep basement in a steeply sloping site in glacial till in Glasgow city centre. Existing foundations, adjacent structures and services, in tandem with asymmetric loading, presented particular challenges in the planning, execution and design of the project. The construction methods and temporary works, analysis by the Finite Element method and monitoring carried out are all described.

Jan 1, 2006

By Vincent Jue

In December 2009, the Italian High Speed Rail Network AV began running over the full 1000 km system length from Turin, at the foothills of the Alps to Salerno, on the seacoast south of the volcano Mt. Vesuvius. It runs through Alpine rivers, highly seismic active zones, mountains, river plains, and through some of the most densely populated areas in Europe as well as some of its most expensive real estate. The Italian High Speed Network?s technical/economic constraints and its regulatory/socio-environmental concerns well may mirror similar obstacles set to confront the nascent California High Speed Rail Program. The two types of constraints must be dealt with together to reach the best construction solution. It is estimated that more than 20% of Italian High Speed Rail Network costs were spent on ground engineering including over 150 km of tunnels, 200 km of viaducts and bridges and 650 km of embankments and trenches. However, it also is estimated that 25% of costs were spent on social and environmental integration of the new rail lines including over 6 square miles of green offsets, 160 km of anti-noise walls, and 300 agreements for socio-environmental work. This paper will look at four examples of innovative ground engineering solutions, each with its own intricate set of constraints: ? Foundation system for viaducts across the ?Po? and ?Ticino? rivers. ? Soil consolidation under railway embankments ? Requirement of short tunnels for physical and environmental reasons ? Construction of railway stations in a confined right of way

Jan 1, 2010

It's long been suspected that there has been an increase in the incidence of premature failure of rock bolts in underground coal mines over the past ten years. As far back as 2002 a study found a possible contributor to such premature failure in some Australian coal mines might be linked to stress corrosion cracking (SCC) (Crosky et al, 2002). That study suggested the low impact toughness could be a major influence on the susceptibility to SCC of different steel compositions. A subsequent study involving laboratory corrosion tests however failed to confirm any link with metallurgical factors (Villalba and Atrens, 2007), a finding that is at odds with field experience. Some mine sites today are still reporting prematurely failed rock bolts to the rock bolt manufacturers; the failures are being identified at SCC induced. To this end a research project has recently been commissioned at University of New South Wales (UNSW), which aims to identify the environmental factors causing SCC, through field test sites and simulating the conditions within an accelerated corrosion laboratory. This paper outlines the methodology that will be used in this study.

Nov 25, 2010

By Rainer Kahrger

During the last decade, advances were made in solvent extraction/electrowinning (SX/EW) technologies. Combined with heap leaching, these technologies made it viable to exploit large, low-grade oxide copper deposits. The El Abra Mine is a good example for such a deposit. The deposit is situated in northern Chile at an elevation of about 4,000 m (14,000ft), 70 km (45 miles) north of Calama. Codelco sold 51% of the El Abra to Cyprus Minerals in June 1994, with Codelco retaining the balance. In 1993, Cyprus and the engineer on the project began discussions withinternational companies regarding the materials-handling system requiredfor the project. These early discussions were considered critical for this fast-track project.

Jan 1, 1996

By Lily Ruíz

El presente texto evalúa el relave minero de SIMSA con el objetivo de obtener un producto ecológico que pueda ser utilizado como mejorador cationico de suelos y restaure el equilibrio de los suelos ácidos de la selva peruana. Para ello, se desarrolló un trabajo a nivel de laboratorio, obteniéndose resultados satisfactorios. Posteriormente se pasó al nivel piloto donde a través de la experimentación se utilizó el relave en diferentes concentraciones para la producción agrícola y forestal, reafirmando los resultados en las mejoras de la productividad en suelos ácidos.

Sep 9, 2007

By K. I. Afewu

A modified approach to the implementation of Gy?s sampling theory is discussed and used to design a procedure for sampling crushed gold ore feed to metallurgical process plants. The approach involves calibration of certain ore-specific parameters. These parameters were calibrated for two different crushed gold ores en route to grinding mills in process plants. The model predictions were compared with the predictions from Gy?s original model. Far smaller masses of samples are required by the modified model than by Gy?s model at the same relative variance. The representativeness of the sampling procedure if normally distributed errors are assumed was also calculated. These procedures and evaluations lead to significant savings on cost of handling and preparation of the samples and to a quantifiable degree of confidence in the analytical results for the process plant.

Jan 1, 1998