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By Carl Fisher

A microseismic roof fall warning system was field tested in Western and Eastern coal mines in the United States to better define the capabilities and limitations of the microseismic method in predicting roof fall. Microseismic event and energy type data were obtained and documented for twenty-three coal mine roof falls, Field test results indicate that both the microseismic event and energy methods, as applied in this development effort, have a high probability for successful application in a commercially practical roof fall warning system. Based on the results and experience obtained during field testing, a commercial prototype microseismic roof fall warning system was designed and constructed. Although it was the intent of the program to field test the commercial prototype system, delays in equipment fabrication and contract time limitations did not permit field testing.

Jan 1, 1980

By J. Sammarco

The U.S. National Institute for Occupational Safety and Health (NIOSH) is conducting mine illumination research to determine if light-emitting diode (LED) cap lamps can improve safety by reducing glare. Glare can impede a miner?s ability to see hazards and to safely perform their work. Another objective is to determine if a person?s age is a factor. This is important because the workforce is aging ? the average miner is now about 43 years old. Three cap lamps were used to evaluate glare: an incandescent cap lamp, a commercially available LED cap lamp and a NIOSH prototype LED cap lamp. Thirty NIOSH personnel from the Pittsburgh Research Laboratory (PRL) served as test subjects. Three age groups were established with ten subjects in each group. Testing was conducted in the Mine Illumination Laboratory (MIL) of NIOSH PRL. The results indicate no statistically significant difference in discomfort glare among the incandescent and LED cap lamps. However, an analysis of variance for disability glare indicates that the LED cap lamps were superior for the older subjects. Disability glare scores for the oldest subject group improved 53.8% when using the NIOSH prototype LED cap lamp compared to the incandescent cap lamp and 36.5% compared to the commercial LED cap lamp. It ap­pears that, given the conditions of this study, LED cap lamps will not increase discomfort glare and can enable significant improvements in disability glare for older workers. It is also evident that not all LEDs are created equal. The disability glare improved the best for older workers when they used the NIOSH prototype LED cap lamp, which has a different spectral power distribution (SPD) (more short wavelength energy) than the commercial LED cap lamp. Therefore, for disability glare, the results suggest that the SPD is an important factor to consider in cap lamp design.

Jan 1, 2009

By E. P. Sadowski, R. J. Raudebaugh

A study of micro structural characteristics of a 30 pct Cr, 42 pct Ni, 26 pct Fe alloy has been correlated with its behavior in creep and rupture tests at 1400°, 1600°, and 1800°F. Nitrogen pickup observed at 1600" and 1800°F was associated withfissur-ing of specimens prior to fracture. IN studying the high-temperature characteristics of a nominally 30 pct Cr, 42 pct Ni, 26 pct Fe alloy certain anomalies were observed, namely: The alloy had greater stress rupture and creep strength at 1800" than at 1600° F for time periods beyond 550 hr. As placed in test, this alloy was nonmagnetic. After test, some specimens were found to be fairly magnetic. The gain observed in magnetic response was not solely a function of time and temperature of testing. This is a report of the observations and a recounting of the results of studies made in an attempt to explain the behavior of the material under investigation. MATERIAL AND PROCEDURE All test material was taken from a production size heat of an experimental alloy melted and processed using commercial practice and having the following percentage composition: C Fe Cr Ni Ti 0.05 25.83 30.13 41.59 0.41 Al Mn Si S Cu 0.42 0.75 0.45 0.011 0.34 The material was tested in two conditions, namely mill-annealed and grain-coarsened. Mill annealing, which consisted of heating to about 1900° F in a continuous furnace for about 30 min and air cooling, gave a grain size of ASTM 8 and finer. To produce the grain-coarsened condition, mill-annealed material was soaked for 2 hr at 2050°F in a laboratory furnace and air cooled. This resulted in an ASTM grain size of 4 to 5. Rupture tests were carried out at 1400, 1600, and 1800° F in accordance with ASTM procedures. In tests where only rupture life and elongation at fracture were determined, specimens of 0.252 in. diam and 1 in. gage length were used. In tests where creep curves were obtained, specimens were of 0.375 in. diam and 4 in. gage length. Several of the tests under relatively low stress were discontinued short of rupture. Three low-stress tests are still in progress at this writing. Structural changes which occurred during testing were determined from examination of the tested specimens by light microscopy and X-ray diffraction. Diffraction pattern recordings were made with a diffractometer using copper radiation on samples heavily etched in a picric-hydrochloric

Jan 1, 1960

By F. K. Shelton, J. C. Stah, Ruth E. Churchward

A study of the hydrometallurgy and electrowinning of cobalt from various domestic ores has been in progress at the Boulder City, Nevada, Experiment Station since February 1940. Previous reports covering certain phases of this investigation have been published. This report covers the research and pilot-plant work on the production of cobalt metal from cobalt-copper ores from the initial experimental work on crude ore through continuous operation. The ore types were from the Blackbird District, Lemhi County, Idaho. The initial tests were made with concentrated ore which was received by air mail and these experiments were expanded both in size and scope. After the laboratory was continued, improved, and extended tests were reported. Sufficiently advanced, a continuously operated plant producing 250 pounds of electrolytic cobalt per day was operated from June 15 through July 15, 1944.

Jan 1, 1948

The Crown Minerals Act provides a new+framework for the management of Crown owned minerals and requires that regard be had for the principles of the Treaty of Waitangi. The Act requires the preparation of Minerals Programmes to achieve the Act's objectives of efficient allocation of rights and the recovery of a fair financial return on its minerals. Efficient allocation requires that a permit is allocated to the party which values it most highly. A fair financial return to the Crown must be considered in the context of the economic rent available from individual mineral projects, with the proviso that a nil return to the Crown as the owner of the resource will not be considered a fair return from the community's perspective.

Jan 1, 1992

By C. E. Hales

In an effort to improve efficiencies and reduce costs, AngloGold has embarked on a process to develop and deliver consistent, high quality, tailings based support or construction products to stopes and tunnels on request. A three-phase approach of product conceptualisation, design and delivery has been adopted. To date a substantial amount of laboratory development has taken place with promising results, indicating that the project aims are achievable. Dans un effort pour améliorer le rendement et réduire les coûts, AngloGold s’est embarqué dans une opération qui vise à développer et fournir aux chantiers d’extraction et tunnels, sur demande, des produits de construction ou de support basés sur rejets qui sont réguliers et de haute qualité. Une méthode à trois volets a été adoptée : conception, création et livraison. A ce jour, un développement important en laboratoire s’est produit, avec des résultats pleins de promesses, qui semblent indiquer que les buts du projet peuvent être atteints. In der Bemühung, die Effizienz zu steigern und Kosten zu verringern, hat AngloGold begonnen ein Verfahren zu entwickeln welches auf Anfrage konsistent hochqualitative auf Haufwerk basierender Unterstützung oder Bauprodukte für Abbaustellen und Tunnels entwickelt und liefert Eine Dreiphasenplan zur Produktkonzeptualisierung, Design und Lieferung wurde adoptiert. Bis jetzt hat eine substantielle Anzahl an Laborentwicklung mit vielversprechenden Resultaten stattgefunden und aufgezeigt, daß die Projektziele erreichbar sind.

Jan 1, 2003

By N. W. Bliss

"Bauxite has been the almost universal ore of aluminum for about 100 years, with most of the world's reserves oc¬curring in the developing countries. As a result of fiscal and political activities prompted in part by the energy crisis, the formation of the IBA combined with increasing freight and labour costs, these reserves are no longer as competitive or as secure as they once were. This has given fresh impetus to the development of processes for alumina production that utilize raw material other than bauxite. Canada has no bauxite and it is prudent to look for alter¬native raw materials within our own boundaries suitable for one of these processes.Of the three igneous rocks that have been used as a source of alumina, only anorthosite is considered as a potential source in Canada. The Al content would be extracted by a sinter process, which currently requires a raw material with a. minimum of 28% Al2O2. Thus, about 4 tons of anorthosite and 10 to 12 tons of limestone are needed to produce one ton of alumina. There are two petrologically distinct types of anorthosite, one containing the plagioclase andesine-labradorite and around 26% Al2O3, and the other containing upwards of 30% Al2O3, in by¬townite-anorthite; for our purposes they may be con¬sidered as low- and high-alumina anorthosite respectively. The high-alumina anorthosites are somewhat rare; the low-alumina anorthosites are much more common, partic¬ularly in Eastern Canada. Geologically speaking, there is no shortage of anorthosite in Canada. The reserves are im¬mense, although their low Al2O3 content coupled with con¬siderations of location, access and proximity to limestone could be constraints to their development. Fly ash from coal-fired thermal power stations and nepheline syenite can also be used in a sinter process, but neither is likely to be utilized in Canada in the immediate future.The H+ process utilizes an acid attack to leach Al from a raw material with at least 20% Al2O3. One of the best raw materials is kaolinite-bearing clay; not only is it high in Al, but most of it can be extracted. With the possible exception of the Whitemud clay in Saskatchewan, Canada is apparently deficient in clays with sufficient reserves to support an alumina plant utilizing the H+ process. Low-alumina clays with illite and montmorillonite may also prove to be a suitable raw material if advantageously sited with respect to industrial centers. The average shale con¬tains only 15% Al2O33, much of which may be contained in minerals, such as feldspar, not amenable to acid leaching. If shale is used as a source of alumina, it will be because it contains some other valuable commodity, such as oil or uranium, the extraction of which leaves the spent shale upgraded in extractable Al2O3 and lowers the over-all costs to a point where it is economic, Thus, rejects from coal washing plants are most commonly considered as a source of alumina; they are already mined, are available in large and ever increasing amounts, and may contain significant amounts of combustible material which upgrades the Al2O3, content of the resulting ash. Coal rejects from existing and developing coalfields in Alberta and British Columbia are a possible source of raw material, but present data indicate they may contain insufficient Al2O3."

Jan 1, 1976

By R D. Lama, A Misra

One of the major factors restricting an increase in the productivity of a longwall mine is lower productivity obtained in a development panel. There has been a significant improvement in gate road development, particularly in mines requiring high density roof and rib bolting within 2 m of the face. Advance rates have increased from an average of 3 m to 5 m per shift in 1985 up to an average of 5 m to 10 m per shift in 1991. In mines at shallow depths with reasonably good conditions the increase has not been that significant. Advance rates have increased from an average of 7 m to 12 ni per shift in 1985 to an average of 12 m to 15 m per shift in 1991. Compared to the United States' (US) development rates, these are much lower. Extensive research work has been carried out to minimise cutting, wheeling, support setting time, and to optimise pillar length to achieve maximum advance rates. Pillar optimisation is very important in order to expedite adverse rates. This paper investigates various development rate technologies, both present and future, and optimises pillars to improve these dev elupment rates. Pillar optimisation is based upon time and motion studies conducted at mines in the Illawara region of New' South Wales, Australia, and the basic tools of arithmetic.

Jan 9, 1996

By S. Gorzalczynski

The recent trend in underground mine developments is “bigger is better.” This is most certainly evident in the mine shaft and conveyances that operate within its compartments. Today, there are several new installations requiring mine cages that can transport up to 170 passengers. The technology in mine hoisting is advancing to address a combination of higher capacity requirements, deeper hoisting depths and faster winding rates, however, some areas of the hoist plant have not changed in the past 50 years. The most notable of these areas is the shaft compartment guide string and the conveyance mounted safety arrest mechanism. The technology in use today for the protection of passengers in a shaft conveyance from a hoist rope severance incident remains conceptually unchanged from Elisha Otis’ design of 1850. The actual retardation components, the safety dogs, have taken on several forms since Elisha’s invention with the last major design change occurring in the late 1940s. The arrest of a free falling shaft conveyance requires that the shaft guides withstand the energy imparted on them by the safety dogs. There are some very real limitations presented by the use of wood for this application. The new hoisting era will most certainly continue to demand larger capacity equipment, but also an increased awareness toward safety

Jan 1, 2002

By Afrânio Márcio Costa

Placas lingotadas continuamente, não obstante atendam a requisitos como composição química, conteúdo de inclusões, aspectos macro e micrográficos, podem ser desclassificadas por falta de conformidade dimensional. Contrações térmicas, de solidificação e de transformações de fases são partes intrínsecas do processo e são afetadas por alterações na taxa de extração de energia da placa durante o processo. Este conjunto de contrações determina o Fator de Contração de operação, o qual é utilizado para determinar as dimensões do molde que irão resultar na largura especificada, onde o presente estudo determinará o fator de contração dos aços peritéticos. As variáveis identificadas que influenciam no fluxo de calor primário foram: frequência de oscilação, superaquecimento, velocidade de lingotamento e viscosidade do pó fluxante. Identificou-se que o resfriamento secundário e a conicidade utilizado no molde, também são critérios determinantes para obtenção de larguras especificadas. Assim sendo, uma equação de regressão foi desenvolvida para o Fator de Contração.

Aug 17, 2017

By Donald Koch

The project investigated regional impacts of mining on the ground water system of the Powder River Basin by: 1) establishment of a regional ground water monitoring network. and 2)development at a set pit digital computer models to simulate ground water flow and quality, ground water contributions to surface water flow and quality (i.e., baseflow), and watershed run-off and recharge. Over 100 wells were monitored for physical and chemical parameters. Data were used as input to the models and for the development of a comprehensive data base. The basin was modeled on a regional and subregional scale using a finite -difference model employing an alternating difference technique. Two water-shed models were evaluated fur their ability to provide runoff and recharge inputs to the basic ground water model. Application of the regional and subregional models using conservative mining scenarios showed that drawdowns may extend west from the mines as far as ten miles but that impacts would be insignificant on a regional scale. The watershed model could be effectively applied to small watersheds only.

Jan 1, 1982

By P. Marinos, G. Tsiambaos, H. Saroglou

Anisotropy is a characteristic of intact foliated metamorphic rocks (slates, gneisses, phyllites, schists). ?esting was used to establish the anisotropic behaviour of selected gneissic rocks. The effect of anisotropy on various mechanical properties (strength, deformation) and dynamic properties (wave velocity) was examined. The rock samples were also tested at successively higher confining pressures in order to evaluate the effect of anisotropic behaviour at high overburden pressures. L’ anisotropie characterise les roches foliées (schistes, gneiss, phyllades). Dans ce travail des essais en laboratoire ont été exécutés afin de déterminer le comportement anisotropique des roches gneissiques. L’ effet de l’anisotropie a été examiné par rapport aux propriétés méchaniques (résistance, deformation) et propriétés dynamiques (vélocité ultrasonique). En outre des essais des roches ont été exécutés a des compressions latérales successivement plus grandes afin de déterminer le comportement des roches sous grands charges. Anisotropie ist eine Eigenschaft der geschieferten Gesteine (TonSchiefer, Gneis, Phyllit, Marmor). Versuche wurden durchgeführt, um anisotrope Verhalten von gneis Gesteinen zu ermitteln. Der Einfluss von Anisotropie auf mechanische (Festigkeit, Dehnung) und dynamische Eigenschaften (Wellegeschwindigkeit) wurde bestimmt. Die Dreiaxialversuche wurden unter grossem allseitigen Drücken entnommen, um das anisotrope Verhalten auf grösse herrschende Spannung zu bestimmen.

Jan 1, 2003

By John P. Capp

Information is summarized on the major uses of fly ash and prospects for utilization in agriculture and in brick and mineral-wool manufacture. Technological aspects of utilization are discussed and references are given to the work of many of the leaders in the fields of fly ash production, processing, and utilization.

Jan 1, 1970

By D R. Swinbourne, T Lehner

Study of the distribution of minor elements between copper matte andfayalite slag is important in determining appropriate methods tomaximise the recovery of valuable metals and the rejection of harmfulelements. Boliden Mineral AB operate a large copper smelter in northern Sweden, where they had noted that the loss of silver to the slag in the settling furnace appeared to be a direct function of the tin content of the slag. This work was aimed at determining whether or not this was a cause-and-effect relationship. Copper matte containing approximately 50 wt per cent copper and small amounts of silver and tin was equilibrated with silica-saturated fayalite slag at 1250¦C, then quenched. The matte and slag were then analysed for their silver and tin contents. It was found that there was no relationship between the silver distribution and the tin distribution. The silver matte/slag distribution ratio had a value of 120 ¦ 40 while that for tin was 2.8 ¦ 0.3. It is suggested that the most likely cause of the relationship observed at the Boliden smelter was matte entrainment in the slag.

Jan 1, 1999

By D. O. Downing

"The 1990s saw enormous changes in the Canadian coal industry and the future promises to be no less turbulent. While the markets served by Canadian coal producers have changed and buying practices continue to evolve, the coal mining, or supply side, has also changed remarkably in response and now provides the basis for an interesting industry story.The dynamic situation in coal mining has led to some surprising outcomes and seemingly contradictory developments. This paper outlines the changes that have occurred, and which are still unfolding in Canadian coal mining, firstly, in terms of mining technology and productivity, secondly, in terms of corporate divestments, acquisitions and bankruptcies, and finally, in terms of resource development. The paper also outlines some plausible futures for the industry looking ahead."

Jan 1, 2002

By A. R. Harrington

BEFORE discussing some of the technical aspects of the steam generating plants of Nova Scotia Light and Power Company, Limited, it might be of interest to go back through history and see the development of steam generation in this public utility. Back around 1902 Nova Scotia Light and Power Company, Limited, had three slide-valve engines in-stalled at its Water Street, Halifax, generating station for a total capacity of 1,800 kilowatts. The plant remained at about this size until 1910 and in 1911 a 2,000 kilowatt steam turbine was installed to raise the total capacity of the plant to 3,800 kilowatts. In 1916, a 3,000 kilowatt turbine was installed and one of the slide-valve engines was removed to make a total plant capacity of 6,200 kilowatts. The total demand in the Company's service 8rea was at that time 4,000 kilo-watts.

Jan 1, 1958

By Sandra Penttinen

To assist blasting professionals with the creation, documentation, and appropriate methodology to standardize the data collection of the pre and post blast investigation process. Penttinen Associates will present a logical non-technical presentation focusing on: Why pre-blast surveys SAVE How to prepare for pre-blast inspections What to do in preparation of pre-blast inspections The creation of an industry standard all-inclusive pre-blast document Establishing pre-blast inspection operational standards Preserving the data.

Jan 1, 2001

By S. H. Ash

THE ANTHRACITE region of Pennsylvania contains over nine-tenths of the total anthracite deposits of North America and produces all but an insignificant proportion of the total output of anthracite in the Nation. The whole economy of the northeastern section of the United States depends, to a large extent, on the mining of Pennsylvania anthracite, which is shipped to New Jersey, New York, and New England and is a principal source of energy and heat for that entire region. The responsibility of the Federal Government for developing an engineering method that will prevent inundation of the Pennsylvania anthracite mines and keep them in operation has long been recognized. To obtain a reliable picture of the anthracite-mine-water problem and to solve that problem, it is necessary to have factual data on the volume and the quality and character of the mine water handled by the pumping plants in the anthracite region, as well as the kinds of pumps utilized and problems concerning their operation.

Jan 1, 1953

By M C. Goode

The use of electrical or electronic safety systems to protect personnel, and the engineering tasks associated with the design, manufacture and maintenance of these systems are referred to using the term ‘functional safety’. In the past ten years, the use of such systems has transitioned from its traditional base, in oil and gas major hazard facilities, to being a part of most large mining and materials handling projects. In particular, functional safety is rapidly becoming a significant component of Australian iron ore projects, typically in the form of emergency stops, remote isolation, drive through interlock, robot cell entry or mobile machine anti-collision systems. While these types of systems have been in use in iron ore for a long time, functional safety standards (eg AS61508, AS62061, AS4024.1503) require more rigourous demonstration of the level of risk reduction provided by the systems.The early engineering project development phases require a number of key decisions to be made around functional safety implementation. The decisions made at this point in a project will go on to dictate the required types of risk assessment and analysis, equipment selection, sizing of substations, and training and maintenance requirements for owners. For project teams that are unfamiliar with functional safety, or inexperienced in its application, an incorrect decision or failure to understand the requirements of the chosen standard can lead to a failure to meet contract requirements, as well as major cost and schedule overruns.This paper examines the implications of functional safety on early engineering studies, focusing on the following questions: How does a designer or company determine what standard is best suited to their project? What key aspects of functional safety design need to be considered during project development? And finally, how can the impact of functional safety to the project be minimised?CITATION:Goode, M C, 2017. Functional safety impacts on study stages of major projects, in Proceedings Iron Ore 2017, pp 347–352 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By J. Bongarra

This report describes the development of the instructional design and content of a training program for shaft construction miners and supervisors. The recommended training approach is based on the results of a needs, task, and competency analysis of the jobs performed by conventional shaft sinking and raise drill personnel. Learning objectives were derived from the task analysis and the appropriate training delivery system was chosen using a selection technique which employed learning algorithms. The training described is aimed at improving the safety and efficiency of constructing shafts by new hire and experienced miners and supervisors. A self-paced, self-teaching, modular approach to training, using criterion-referenced tests was proposed. Recommendation was made to divide the training into three parts: Orientation and Safety; Task Instruction; and Practical Exercise. Training requirements for conventional shaft sinking and raise drilling were described. Training program content was detailed in the form of module and lesson design approaches. In addition, the report recommends a method for developing, implementing and validating the training program. The authors conclude that such an implementation would meet the major objectives of improving the safety and efficiency of shaft construction work operations.

Jan 1, 1979