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By C MacDonald

There are many technologies available today in terms of fire and life safety in road tunnels. So many in fact that it is becoming more and more difficult for clients and contractors alike to determine what they want and what they need. From a clientÆs perspective, fire and life safety is about protection to its infrastructure and to the public at large. Conversely, the contractor is looking to meet its æfit for purposeÆ or ædeem to complyÆ requirements in the most economic and practicable way. Practices regarding fire and life safety in road tunnels have undergone a degree of transformation during the last decade or more throughout the world. This transformation has largely been driven by a series of catastrophic accidents such as the major fires in Europe including the Mont Blanc Tunnel, Tauern Tunnel, Saint-Gothard Tunnel, and now most recently in the CityLink Tunnels in Melbourne. International guidelines produced by organisations such as the Permanent International Association of Road Congresses (PIARC), the European Union, the International Tunnelling Association (ITA) and the US National Fire Protection Authority (NFPA) now provide clients, owners and designers with the tools required to define and specify the required fire and life safety systems in road tunnels. The majority of these tools are based on risk assessment and risk management. Recent road tunnel projects within Australia, however, have not referred solely to such guidelines. Clients have opted to prescribe different or additional fire and life safety requirements within the projectÆs technical specification documentation (project requirements), leaving designers and contractors with little room to implement alternatives or substitutions. Further, these project requirements are largely dictated by practice established on previous road tunnel projects within Australia. This paper looks at the current international guidelines and practices and undertakes a comparison with the EastLink tunnels in Melbourne and other road tunnels within Australia and makes assessment on whether Australian methods are the most appropriate for clients and contractors alike. Focus is directed to the key elements of fire and life safety such as:traffic envelope, barrier arrangements and emergency walkway provisions;deluge systems;drainage systems;fire rating requirements;tunnel ventilation systems;cross passage provisions;fire safety assessment;critical intelligence systems including help phones, CCTV, incident detection, tunnel signage, etc; andexternal tunnel control systems.

Jan 1, 2008

By J. Mackintosh Bell

External trade strongly influences the well being of all nations. In the modern economic mechanism, no country is so well endowed that it has not to import commodities from others and to export its products in turn to make good its deficiencies, to rectify or improve its financial structure. From the standpoint of international commerce, Canada is strategically well placed. On the south she is bounded by the richest country in the world. On the east she faces the Atlantic, on the west the Pacific. On both coasts there are fine harbours to which lead great lines of railway that span the continent. Canada is now fifth among the exporting nations of the world. For disposal abroad, she has enormous quantities of primary commodities and substantial amounts of manufactured goods as well. But she is far from being self-sustaining. She is unusually dependent on foreign trade, not only because of the commodities she has to sell but because of the lack of many essential articles she does not or cannot produce. To Canada, external commerce is vastly more important than internal trade. The wealth of nations is decided by their ability to produce more than they need, to sell more than they buy, and to build up favourable balances resulting from trade or services. With few countries, however, are returns perennially satisfactory. Fruitful periods are followed by leaner years. In times of prosperity foreign credits are increased, monetary systems strengthened, reserves accumulated to withstand recurring days of strain. Today, the foundations of financial systems are being re-examined, "dogmas hitherto accepted as canonical are being questioned" . It is not only in Europe and America that men search for illumination in problems arising from monetary restrictions.

Jan 1, 1933

By G. van Hout, D. Rahal

Caving is a mass mining method that is normally applied to large, low grade orebodies because of its low production cost and high capacity. However, equipment breakdown and poor draw management can cause mining costs to exceed that of all other mining methods. One way to minimize the effect of disruptions in the mining cycle is to use Mixed Integer Linear Programming (MILP) for long-term scheduling. This paper describes a MILP goal program which has the dual objectives of minimizing deviation from the ideal draw profile while achieving a production target. Schedule optimization is performed using a life of mine approach in which all production periods are optimized simultaneously. The underlying assumption being that material mixing in the short-term (between monthly optimization cycles) has a minimal effect on the long-term state of the panel. Schedule optimization is carried out using six general constraint types to model and control production. The constraint types define: deviation from ideal practice, panel state, material flow conservation, production quality, material flow capacity and production control. These constraints define production targets and drive production toward the ideal profile while maintaining correct mining practice. Application of the model using production scheduling data for a De Beers kimberlite mine. It is shown how different production control constraints regulate production from individual drawpoints as well as recovery of the ideal panel profile by implementing an optimised draw schedule.

Jan 1, 2003

Entry of personnel under a vertical raise bored hole is not standard practice in Australia. Where access is required below a rise, mining operations must be confident that they understand the capacity of the ground control specified and installed. Physical modelling was conducted on Callie mine to evaluate the performance of 5 mm steel wire weldmesh secured to the base of a vertical raise bored hole of 1.4 m diameter. Joint orientation data was used with Unwedge to calculate a series of potential wedges likely to form within the rise. The mass of the most likely wedges were then replicated by collecting rocks in 5 kg increments (¦10 per cent), which were allowed to freefall onto installed mesh at the base of a 40 m vertical rise. The results indicate that two sheets of mesh can retain a freefalling rock of at least 20 kg mass although rupture of strands can result. This paper outlines the test conditions, expected results based on theoretical calculations and actual outcomes of the testing.

Nov 25, 2010

By N. R. Dixon

This report summarizes all work performed under U.S. Bureau of Mines Contract No. J0395028, "Noise Control of Rubber-Tired Front-End Loaders Used in Surface Mining. " Two loaders, a Caterpillar 988 and an International H-400B, were chosen for this program, and the noise sources and acoustic paths that contribute to the operator's noise exposure were identified. Retrofit noise control treatments were designed and installed on these loaders, and noise reductions of more than 10 dBA at the operator position were achieved on both machines. The retrofit packages are low cost and have been field tested in two mines for more than two years. The results of the program were communicated to the mining industry through a series of noise control workshops and a field manual. The workshops were given in nine states across the U.S. and more than 440 manuals were distributed An audio/visual slide presentation was also developed which the program.

Jan 1, 1983

By S. E. Chetlin

In the mid-1970?s, the market value of tangible assets of S&P 500 companies far outstripped the value of intangible assets, including intellectual property (e.g., 83% tangible assets v. 17% intangible assets).1 By 2005, the picture was quite different. By that time and continuing to 2010, S&P 500 companies? market value of intangibles was about 80%, with tangible assets accounting for only 16% of market value.2 This swing highlights the importance in today?s world of understanding intellectual property rights and varying strategies and options for protecting them. This paper discusses intellectual property rights particularly patents and trade secrets, specifically: 1) types of intellectual property; 2) choosing the mode of intellectual property protection; 3) obtaining patent protection; and 4) using patents as a sword versus a shield.

Jan 1, 2012

By R. A. McIvor, R. Levac

"The Stobie No. 7 shaft, 14 ft diameter, double- drum skip hoist, was installed at the INCO Limited Frood Stobie Complex in 1942. Figure 1 shows the hoist layout. The hoist was originally equipped with babbitted journal bearings on the main drum shaft and pinion gears. In 1990, the hoist was modernized with a new braking system, two new 2000 hp D.C. drive motors, a thyristor armature supply and a PLC control system. The new drive motors were connected to the drive pinion gears with a gear type flexible coupling. The pinion gear journal bearings were refitted during the refit in 1990 as the existing babbitted bearings showed signs of wear. The pinion gear journal bearings had always run warm and had external cooling applied during the warm summer months. Figure 2 shows the journal bearings on the pinion shaft. The skip hoist main bull gear and two pinion gears were replaced in 1997 because of cracked bull gear spokes. New drive couplings were installed on the pinion gears and the pinion journal bearings were modified to allow some self-aligning properties to try to reduce the heating and wear on the babbitt. The modifications did not significantly reduce the heating problems and a decision was made in the spring of 1998 to convert the bearings to self-aligning, anti-friction-type bearings.The traditional roller bearings used on double helical pinion drive gears in hoist applications has always been double-row spherical roller bearings due to their high load-carrying capacity and misalignment allowances.Unlike single helical gears, double helical arrangements do not exert axial thrust on the pinion gear bearings, therefore, both bearings in the pillow blocks must float easily with any pinion displacement. Drum misalignment, thrust bearing end play and a multitude of other influences causes continuous axial displacement of the pinions when in operation. This constant displacement or “hunting” of the pinion gear to maintain its centre on bull gear often exceeds the axial clearance limits of spherical roller bearings thus resulting in a continuous sliding motion of the bearing outer rings against the housing seats. With time, the housing fit eventually wears, creating an out-of-round condition for bearing housing (maximum allowable cylindricity tolerance is IT4/2). When this happens, the pillow block housings must be replaced or re-machined to specification. Premature bearing wear and overheating will occur if a housing out-of-round condition is encountered."

Jan 1, 2001

By Brown H. R, Wright E. A

The authors identify the workable coal seams, their distribution in relation to quality and economic occurrence and relate their analytical characteristics to industrial use. The development of established collieries is also discussed with regard to increased production demand.The authors also indicate the potential of the coal resources of the Southern District and postulate their ultimate development.INTRODUCTIONThe Southern Coalfield yields 30 per cent of the total production of bituminous coal in New South Wales. The economic potential of the coalfield was examined last by Harper (1915). Since that time additional knowledge has been gained by prospectors, mining companies and public authorities. Expansion in the steel industry and the building of power stations on the coalfields together with improvements in fuel technology, mining methops and road transport have resulted in production of coal from seams mice thoughtto have no economic value.DESCRIPTION OF THE COALFIELDFor the purpose of this paper the term Southern Coalfield includes also the South-Western Coalfield which together comprise the following Coal Districts:IllawarraDouglas ParkWollondilly-NattaiMoss Vale-Berrima (Hanlon, 1953).Geographically the coalfield is contained by the Illawarra Range in the east, the Shoalhaven River to the south, the Wollondilly River to the west, and in the north by a line...

Jan 1, 1958

By M. J. Beus

This paper will describe the research approach being initiated by the Spokane Research Center to assess hazards and design criteria to prevent ground and muck falls in and around ore passes in hard-rock mines. The major goal of this research is to compile detailed information about ore pass processes and hazards, identification and testing of prevention strategies, and development of computer-based measurement and design methods. Recent ore pass failures have underlined the lack of OE pass design capabilities and standards available to both mine engineers and MSHA personnel. Design criteria and ore pass hang-up prevention and remediation strategies will include the effects of internal ore pass loads, blasting to relieve hang-ups, and rock mass stress redistribution and structural interaction from nearby mining. New visualization and three- dimensional analysis methods will be presented as an extension of existing ore pass design and analysis techniques. A sophisticated particle-flow analysis program will be used to simulate the response of various ore pass designs to a wide range of loading conditions driven by rock mass deformation, muck flow, ore pass blockage, and blasting in both nearby stopes and the ore pass. Analysis techniques will be calibrated and design criteria validated at the Spokane ore pass test facility. These tools will serve to reduce research costs by limiting the number of experimental field tests required.

Jan 1, 1996

By Sandip K. Mukherjee

This report presents the results of the economic analysis of several applicable alternatives to increase airflow in four underground coal mines. Pressure-quantity surveys were conducted underground and measurements were also made at the main mine fan(s). The existing ventilation networks were modeled using the modified Penn State ventilation simulator. The applicable alternatives were simulated. Performance data obtained from these simulation runs were utilized to conduct the cost-effectiveness analysis. The costs for each of the alternatives included capital, operating and operating costs. These costs were expressed as annual ventilation costs per active section in terms of dollars per cfm taking into account the economic life associated with each of the alternatives. The benefits were expressed as increased airflow quantity in the critical sections. A section of this report also deals with comparison of simulator predicted air quantity values against air quantity values measured under-ground. This volume constitutes Volume II of the report and contains the outputs of the computer simulation runs.

Jan 1, 1983

By G. C. Lammers

The object of this study was to determine the economic feasibility of hydraulically transporting Sandow (Tex.) lignite 100 miles and dewatering and thermally drying the transported lignite to a surface-dry condition. The most important factors involved in the feasibility of hydraulic transport, are the degradation incurred during transit, the length of the line, and the cost of alternative methods of shipment. In pipeline tests in which roughly 75 miles of hydraulic transport was simulated the percentage of minus-325-mesh solids increased from about 1 to 41 percent for both lignite and bituminous coal; in the micron sizes the coal fared considerably better than the lignite. Such degradation, even though it enhances flow through the pipe-line, severely aggravates the dewatering problem on lignite. Cost studies indicated that continuous vacuum filters offer the most economical means of dewatering minus-1/8-inch material. Surface moisture, if high, must be removed by relatively expensive thermal drying.

Jan 1, 1958

By R. R. Joseph, K. A. Gschneidner

The solid solubility of magnesium in the close-packed modifications of lanthanum, cerium, praseodymium, neodymium, gadolinium, dysprosium, and lutetium was determined from approximately 250°C to the eutectoid temperature by the X-ray parametric technique. The maximum solubility at the eutectoid temperature was found to be 9.4 at. pet in La, 8.2 in Ce, 9.2 in Pr, 8.2 in Nd, 14.1 in Gd, 13.5 in Dy, and 11.5 in Lu. The solubility when compared at a homologous temperature was found to increase in a smooth manner with decreasing size factor from lanthanum to lutetium. It was found that the apparent atomic radius of magnesium when dissolved in the lanthanide solvent was constant and could be accounted for by consideration of several models dealing with departures from Vegard's law. The eutectoid temperatures for the lanthanide-rich La-Mg, Ce-Mg, and Nd-Mg systems were found to be 544", 505°, and 551°c, respectively. A study of the solid solubility of magnesium in the lanthanide metals was initiated because the valency and electron egativity difference are essentially constant and favorable for solid-solution formation, and thus one could examine the effect of size on terminal solid solutions. The size factors based on metal radii range from 14.6 pet for lanthanum to 7.5 pet for lutetium. Since the electronegativity difference is small, 0.06 unit or less, application of the Hume-~othery' and Darken and Gurry2 criteria for solid-solution formation indicates that the solubility of magnesium would be expected to be small for lanthanum (between 5 and 10 at. pet) and to increase as we proceed along the lanthanide series. A search of the literature revealed no data on the solubility of magnesium in the lanthanide metals except for the solubility of magnesium in cerium at 450oCA typical phase diagram for the lanthanide-rich end of the lanthanide-magnesium phase diagram is shown in Fig. 1. EXPERIMENTAL PROCEDURES Preparation of Alloys. The lanthanide metals used in the preparation of alloys for this investigation were prepared from the corresponding fluoride by metallothermic reduction techniques previously described by Daane.4 The chemical analyses of the metals used are listed in Table I.

Jan 1, 1965

By J. W. Klokow, K. L. Riemer, R. I. L. Ferreira

As a result of the increased depth of mining in the South African gold mining industry mining induced seismicity is a severe problem. One of the strategies within the industry to contain the problem is to incorporate a system of regularly spaced stabilising pillars into mine layouts. At the Driefontein Gold Mine a system of closely spaced dip pillars is used to contain seismic energy emissions. Comparisons of seismic data for several mining clusters initially indicated a possible measure of success in the containment and occurrence of larger events. A detailed analysis of data over a 5-year period since the start of mining however, has revealed a delayed seismic response to the increasing strike spans. Significant changes marked by an increase in certain seismic variables have been observed at mining spans of between 100 to 120 meters and could be of significance to pillar spacing in the design of deep level mining layouts. La sismicité occasionnée par l’exploitation minière est un problème grave dans les mines profondes de l’industrie minière aurifère en Afrique du Sud. Une des stratégies utilisées dans l’industrie a été de maîtriser le problème en incorporant un système de piliers de stabilisation régulièrement espacés dans la disposition des mines. A la Driefontein Gold Mine, un système de piliers de pendage proches les uns des autres est utilisé pour contenir les émissions d’énergie sismique. Au début, des comparaisons de donnés sismiques pour plusieurs groupes d’extraction ont indiqué un succès possible dans la limitation et l’occurrence d’évènements sismiques. Cependant, une analyse détaillée des données sur une période de 5 années a révélé un délai entre la progression de l’extraction et une réponse sismique accrue. Des changements considérables dans les variables sismiques ont été observés dans des intervalles d’extraction entre 100 et 120 mètres, ce qui pourrait être significatif pour l’espacement des piliers dans la conception de la disposition des mines de fond. Resultierend aus den zunehmenden Tiefen des Bergbaus in der südafrikanischer Goldbergbauindustrie stellt sich die vom Bergbau hervorgerufene Seismizität als bedrohliches Problem dar. Es war eine der Strategien innerhalb der Industrie, das Problem dadurch einzudämmen, daß regelmäßig plazierte Stabilisierungspfeiler in den Bergbaulayouts inkorporiert wurden. In der Driefontein Gold Mine wird ein System von knapp aneinandergesetzten im Abfallbereich befindliche Pfeiler benutzt, um seismische Energieemissionen einzudämmen. Vergleiche der seismischen Daten für mehrere Bergbaugruppen zeigten anfangs ein mögliches Maß von Erfolg in der Eindämmung und im Auftreten von größeren Fällen an. Eine ausführliche Analyse von Daten über einen 5jährigen Zeitraum hat jedoch ergeben, daß eine Verzögerung zwischen der Progression des Bergbaus und einer erhöhten seismischen Reaktion besteht. Bedeutende Änderungen in den seismischen Variablen wurden an Bergbauspannen von 100 bis 120 Metern beobachtet und könnten für Abstandsbemessung von Pfeilern im Design des Tiefbergbaulayouts von Bedeutung sein.

Jan 1, 2003

By Charles Sabine

The U.S. Bureau of Mines studied mines and prospects in the Bristol/Granite Mountains Wilderness Study Area (WSA) in 1982. The 45,000 acre WSA, located in the eastern Mojave Desert of California, is underlain by Mesozoic plutonic rocks with scattered roof pendants of Paleozoic (?) metasedimentary rocks. Two mines and six prospects are identified; one mine, the Silver Lode Mine, and a prospect of unknown name are adjacent to the area. The Silver Lode Mine has occurrences of silver, lead and zinc. Within the study area, the Comanche Mine has occurrences of iron and copper and the Iron Victory Prospect has an occurrence of iron. None are large enough to constitute a resource. Occurrences of magnesian marble at the Comanche Mine, Iron Victory Prospect, and elsewhere in the area contain too much MgO for commercial use other than agricultural soil supplements or crushed stone. Transportation costs to markets would exceed the value of the rock. At the Comanche Mine, situated in a roof pendant of marble, about 10 tons remain of a 110-ton pod of magnetite which contained 42.5% iron, and less than 50 tons remain of a mineralized fault breccia which averaged 2.5% copper and 0.3 oz/ton silver. Magnesian marble contained 41 to 45% CaO and 14 to 16% MgO. Primary and secondary silver, lead, zinc, and copper minerals are disseminated along altered joints and in quartz veins in quartz monzonite at the Silver Lode Mine, adjacent to the WSA. Analytical data are sporadic; samples contained as much as 0.12 oz/ton gold, 1.8 oz/ton Silver, 1.1% lead, 3.8% zinc, and 0.3% copper. Mineralized zones in the workings are not resources, but they might indicate possible silver-lead-zinc resources at depth. At the Iron Victory Prospect, lenses of magnetite and hematite with some chalcopyrite occur in a skarn lone in a marble roof pendant. About 110,000 tons of iron-rich rock, averaging 47.2% iron, are present; the largest lens contains about 30,000 tons. About 150,000 tons of magnesian marble, averaging 41.0% CaO and 11.7% MgO, are also present. Deposits of stone, and sand and gravel in the WSA are too distant from markets to be resources. Occurrences of energy minerals were not identified.

Jan 1, 1984

By H. E. Powell

A laboratory investigation was conducted by the Bureau of Mines to study the magnetic characteristics and to measure the magnetic susceptibility of the mineral siderite. All susceptibility measurements were made by the method of Gouy on powdered samples and at room temperature. Specific susceptibilities of samples from 15 different locations, domestic and foreign, were determined. Values ranged from 66 to 103 (10-6) cgs electromagnetic units. The relation of susceptibility to mineral composition is discussed in this report. The specific susceptibilities of 76 minerals are tabulated in an appendix.

Jan 1, 1963

By Fred E. Fiedler

A demonstration project investigated the feasibility and effectiveness of two management interventions, Management Training and Organization Development, for improving productivity and safety in metal/non-metal mines. The management training intervention was conducted at Texasgulf Company's trona mine, using three nearby trona mines as controls. The Organization Development intervention took place in Hecla Mining Company's Lucky Friday mine, using the highly similar Star Mine as control. The two management interventions seemed about equally effective in reducing accidents and injuries, as well as MSHA citations, and the management intervention at the Texasgulf mine also appeared to have led to substantial improvement in mine productivity.

Jan 1, 1983

By T. J. McKeon

Partition curves are used to evaluate the separation performance of gravity-based concentrators. The partition curve is used to identify the nominal density cutpoint and relative sharpness of the separation. In addition, the graphical representation makes it possible to quickly identify the root cause of misplacement based on the characteristic shape of the partition curve. Partition curves have been traditionally constructed using data obtained from float-sink tests using heavy organic liquids. These toxic liquids are environmentally unfriendly and have been banned in several countries. Another method of establishing the partition curve is to introduce density tracers into the feed and plot the distribution to the lights and heavies. For heavy mineral separations, this approach is generally impractical due to the fine particle size. In addition, the partition data obtained using these existing techniques do not account for secondary factors such as particle shape that may influence the separation. In light of these problems, a methodology was developed for constructing partition curves using experimental data obtained from microscopic grain-counts. This technique, which essentially uses the different mineral species as density tracers, provides a powerful tool for evaluating heavy mineral separations. A case study is provided to demonstrate how this analytical approach can be used to assess and improve the separaton performance in an industrial upgrade plant.

Jan 1, 2005

By M. van Schoor

Coal remains South Africa?s most abundant and cheapest source of energy, and there is an ever-increasing necessity for optimal and safe extraction of the remaining reserves. Increasing focus on cost-effective mining and zero harm to the environment and miners has resulted in a shift in attitude towards the application of geophysics in local coal mining and exploration. Furthermore, technological advances have contributed to geophysics being embraced more readily by the coal mining industry, compared to a decade or two ago. Predictably, the growing interest in geophysical technologies has also created a need for education and training in the basic principles and application of geophysical methods, as local coal mining companies generally do not have in-house geophysicists. Consequently, the Coaltech Research Organisation?s Geology and Geophysics working group forum compiled a textbook aimed at addressing this need: to produce a guide for applying geophysics to coal mining problems in South Africa. The target audience for such a book would be coal geologists, mine surveyors, mine planners, and other mining staff with limited or no geophysics background. This paper provides a very brief overview of the book by summarizing key sections and selected examples. In doing so, the value of geophysics to solving a range of coal mining and exploration problems is highlighted.

Jan 1, 2014

By LaMar G. Evans

The rapid determination of uranium in ores by radiometric means was investigated by the Bureau of Mines. Among the various procedures and schemes tested, two showed most promise. They were the ratio scheme developed in the Bureau's Tucson, Ariz., laboratory and the equilibrium method developed by the Canadian Department of Mines and Technical Surveys. The ratio method is a simple, empirical procedure for classifying the state of equilibrium in ores by measuring their radioactivity by means of a Geiger-Muller counter under three different conditions, using filters. The principal merit of the method is in providing a clue as to the reliability of equivalent uranium determinations.

Jan 1, 1958

This study was conducted to determine the feasibility of using large tractor dozers in land reclamation of strip-mined areas. The procedures used are patterned after engineering models developed for evaluation of military ground vehicles in cross-country operations. Tractor dozer manufacturers furnished information on capabilities of existing equipment and ideas on the practicability of using dozers larger than those currently available Generally, they believe that current dozers in the 500? to 700-horsepower range are about as large as can be built and remain economically feasible. However, one manufacturer has a wheeled dozer rated at 1200 horsepower, and another is testing a tracked dozer of about the same horse-power.

Jan 1, 1975