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By T. H. Aldrich

(Chattanooga Meeting, October, 1908.) Tars paper is intended only to give a preliminary account of experiments made, and conclusions reached, concerning the treatment of certain refractory low-grade gold-ores, the profitable reduction of which may furnish a useful guide to the solution of similar mining and metallurgical problems, not only in the gold-bearing belt of the Southern United States, but perhaps in other regions also. It must be regarded as simply a ?report of progress," preceding a more elaborate and conclusive report of regular practice. The mines of the Hillabee Gold Mining Co. are located upon what is generally known locally as Hog Mountain, on the northern edge of Tallapoosa county, Ala., about 15 miles from Goodwater and 14 miles from Alexander City, stations on the Central of Georgia Railway. Gold has been known since 1839 to exist on this property, where it was discovered in that year by a man named Johnston. The property was worked for placer-gold by the old miners, and there are now the remains of four attempts to operate it by stamp-mill and plate-amalgamation. The present owners purchased it in 1896, and since that time they have experimented at frequent intervals, in order to devise a process that would satisfactorily recover the gold. In 1903 regular operations were begun. Geologically, the mountain consists of an intrusion of what has been pronounced true granite in altered sedimentary slates. The cooling of the granite produced shrinkage-cracks, which have become veins. There is considerable question as to the period of the slate formation; but it is undoubtedly, in my opinion, of Carboniferous age. The veins, about 50 in number, strike N. 60° to 80° E.; dip approximately 65° from the horizontal; vary from a few inches to 25 ft. (being in gen-

Nov 1, 1908

By Bashir Ahmed, Fred D. Wright

Numerous investigators have studied the various factors that influence the ultimate strength of model mine pillars, such as ratio of height-to-least width; restraint or friction on the top and bottom; 1,2 the effect of stress distribution in pillars on their strength;3 and the scaling factors involved in applying the results of model pillars to full-scale pillars. However, the load-bearing capacity of pillars after initial failure does not appear to have been investigated. Yet many mines employ methods in which small pillars or pillar remnants are left systematically; these pillars crush as mining progresses and, of necessity, affect the behavior of surrounding rock even after initial failure. The effect of such crushed or crushing pillars depends largely on their load-deformation characteristics. This chapter presents the results of a preliminary investigation to determine the load-deformation characteristics of a few model mine pillars to and beyond initial failure. Various investigators have also studied the elastic and viscoelastic behavior of mine structures. In such studies, computers are frequently employed to obtain numerical results by the finite difference or finite element methods. It would be entirely feasible to write a program that would approximate the load-deformation characteristics of pillars to and beyond the crushing stage if these characteristics were known. More accurate information on the induced stresses and deformations in overlying strata and on surface subsidence could be obtained, information which should result in better strata control by enabling the engineer to calculate more accurately the effects of changes in pillar spacing, size, and shape.

Jan 1, 1972

By Tony Lipiec, Greg Gosson

"When it comes to new mines being developed, there is a general industry consensus that most low-hanging fruit has been picked. Many projects currently in the mine development pipeline have been around for decades, but were held back because of technical challenges. Future development of these deposits will likely require access to the public capital markets, and in Canada that means providing scientific and technical disclosure on these deposits in compliance with NI 43-101. As many of these “challenged” projects have metallurgical issues, the companies that own the projects need to ensure their metallurgical Qualified Persons provide transparent disclosure regarding proposed solutions to those issues.This paper provides an overview of the disclosure requirements under NI 43-101 that are pertinent to metallurgists, and other Qualified Persons who prepare technical disclosure regarding the metallurgical characteristics of a mineral project. It lists the triggers for a technical report under NI 43-101 and Canadian stock exchange policies, and identifies the sections of the report that should involve input from a metallurgist or process engineer. It briefly outlines new civil liabilities under Canadian securities laws that increase the possible consequences for not complying with the technical disclosure standards.These materials are provided for general information purposes only and do not constitute legal advice. Readers are advised to seek specific legal advice from their own legal counsel in relation to any decision or course of action contemplated."

Jan 1, 2010

By G. C. Weatherly, L Beitelman, M Gray, M. W. Bates, R Hadden

"A program of evaluation of in-mould electromagnetic stirring on the product of a straight-mould, billet continuous casting machine has been carried out. The effects on macrostructure, surface and internal quality, chemistry segregation and mechanical properties on carbon, low-alloy and resulphurized, free-machining steel billets and rolled bars are discussed. Operational aspects as a result of in-mould stirring are highlightedIntroductionA development program on electromagnetic stirring (EMS) in the mould of a continuous caster was started by Ferrco Engineering Limited in 1979, with the first experimental device being developed and installed at Lake Ontario Steel Company. As a result of these initial trials, new designs of in-mould EMS systems have been developed and are currently being used in continuous casters in North America and Europe. The rapid progress which has been made is in large measure due to the fruitful cooperation which has existed between the various parties, including Ferrco, the EMS equipment manufacturer, several operating plants and the University of Toronto.A brief review of some of the basic ' principles of electromagnetic stirring action on solidifying metal, and the landmarks of this process development, will explain the philosophy of this cooperation.From casting practice, it is well known that an equiaxed dendritic structure provides better' material properties than a columnar dendritic structure. Homogeneity of the equiaxed structure leads to better control of material properties, such as strength and ductility. Therefore, many efforts are being made to obtain this structure in continuous casting.The extent of the equiaxed zone is determined to a large degree by convective flow in the liquid. Fluid flow can fragment dendrites in the columnar zone, which then act as nuclei for grains in the equiaxed zone farther down the sump. This process is referred to as dendrite or grain multiplication."

Jan 1, 1982

By Jorge Luiz Soares do Couto

O presente trabalho tem como objetivo realizar uma análise comparativa do comportamento de quatro metais de solda obtidos pelo processo arame tubular de forma a avaliar o efeito da relação Ni-Mn nas propriedades mecânicas. Foram soldadas juntas multipasse, com consumíveis da classe 110ksi de resistência mecânica, preaquecimento de 200°C, corrente contínua e posição plana e aporte térmico nominal de 1,2 kJ/mm. Após a soldagem, realizaram-se ensaios mecânicos e metalográficos em corpos-de-prova retirados integralmente do metal depositado, na condição de como soldado e após tratamento térmico pós-soldagem. Os resultados mostraram que as melhores propriedades mecânicas foram obtidas para uma composição contendo 1,35%Mn e 2,50%Ni. Adicionalmente, verificou-se que o tratamento térmico pós-soldagem propiciou uma redução da tenacidade ao impacto dos metais de solda de maior resistência devido à precipitação de carbetos nos contornos de grão.

Aug 7, 2018

By K. Hodgson, J. P. M. Hojem, N. G. W. Cook

Already about one-third of South Africa's coal is mined at depths exceeding 100 metres. Almost all this mining is done by the bord and pillar method. Conventional design procedures call for ever larger pillars as depths of workings increase, resulting in the loss of large amounts of coal and reductions in productivity. Barrier pillars are in general use to ensure against large collapses. The presence of these strong pillars would allow a more efficient design of the bord and pillar layout to yield improved extraction ratios by using smaller, yielding, pillars between the bords. Knowledge of the complete load- displacement curves for such pillars is a prerequisite for the design of such a system. A 100-MN, stiff jacking system for measuring the complete load-displacement curves of pillars with cross-sections of up to 2 m X 2 m is described. The jacks are installed in a slot cut across the central plane of symmetry of a pillar, thereby ensuring that the stress distribution in the pillar during a test, especially at its contacts with the roof and floor, is identical to that caused in a similar pillar by convergence across the seam. Preliminary results in the form of complete load-displacement curves for test pillars of about 1.5 metre square section are given.

By Burden of Occupational Cancer in Canada Project Team, Demers P. A., Kim J., Arrandale V. H., Jardine K.

"In 2012 diesel engine exhaust (DEE) was classified as a human carcinogen by the International Agency for Research on Cancer (IARC) and is one of the most common workplace carcinogens internationally. We estimate that approximately 2.4% of lung cancers (n=560) and a suspected 2.7% of bladder cancers (n=200) are attributable to occupational exposure to DEE annually in Canada. High levels of exposure to DEE in mining results in a disproportionate number of cancers in this sector (approximately 220 lung and 20 suspected bladder cancers annually). These could be prevented by reducing the number of workers exposed and level of exposure. KEYWORDS Bladder cancer, Diesel engine exhaust, Economic burden, Lung cancer, Mining, Occupational cancer, Prevention, Regulation INTRODUCTION Diesel engine exhaust is a complex mixture of gases and particulates containing known and suspected carcinogens such as benzene, polycyclic aromatic hydrocarbons (PAHs), and metals. Approximately 900,000 Canadians are exposed to diesel engine exhaust at work, making it the most prevalent occupational lung carcinogen in Canada (CAREX Canada). Diesel engine exhaust is recognized as one of the most common workplace carcinogens in the world, but its classification as a human carcinogen by the International Agency for Research on Cancer (IARC) was relatively recent. In 2012, after decades of mounting evidence, diesel engine exhaust was upgraded from a probable (IARC Group 2A) to a definite human carcinogen (IARC Group 1) (IARC, 2014). The IARC evaluation was based on strong evidence in humans for an increased risk of lung cancer, as well as strong evidence in animal studies. The key human evidence considered by IARC was from epidemiologic studies of workers in truck transportation, rail transportation, and mining industries, where the use of diesel engines is widespread. These studies provided strong sufficient evidence for an increased risk of lung cancer, as well as limited evidence for bladder cancer. The human studies used particulate matter, generally measured as elemental carbon (EC) or total carbon, as a surrogate for diesel engine exhaust to assess the risk associated with level of exposure. The animal studies reviewed by IARC showed sufficient evidence for cancer with exposure to whole diesel exhaust and the particulate matter fraction of diesel exhaust, but not for the gas phase components."

Jan 1, 2019

1. In 2003, a total of 4,357 stone mining operations reported employment to the Mine Safety and Health Administration (MSHA). The major industrial classifications in stone mining are dimension stone (used for construction purposes), crushed and broken stone (aggregates), cement, and lime. • Stone mines comprised 30.3% of all mining operations. • Mines producing crushed and broken stone (n = 3,412) comprised 78.3% of all stone mining operations.

Feb 1, 2005

1. In 2002, a total of 4,311 stone mining operations reported employment to the Mine Safety and Health Administration (MSHA). The major industrial classifications in stone mining are dimension stone (used for construction purposes), crushed and broken stone (aggregates), cement, and lime. Stone mines comprised 29.7% of all mining operations. • Mines producing crushed and broken stone (n = 3,372) comprised 78.2% of all stone mining operations.

Jan 1, 2004

By George K. Burke

Single axis soil mixing is a mechanical method of blending soil in situ with a reagent binder to achieve improved character. Generally this achieves a design compressive strength or shear strength and/or permeability, but can be used to immobilize and/or fixate contaminants as well as a treatment system for chemical reduction to a more "friendly" substrate. The reagent binder can be a variety of materials, including cement, fly ash, slag, lime, and an assortment of additives. Usually this reagent is delivered in a slurry form (combined with water), but the Dry Mix Method uses pneumatic conveyance.

Jan 1, 2001

By William Babcock

Augered, Cast-In-Place (ACIP) piles can be an economical, reliable, versatile foundation system. They have also been a part of projects that were behind schedule and the subject of lawsuits. The ACIP pile is a specialty system that is more workmanship dependent than most deep foundation systems and is especially vulnerable to the problems and abuse of poor specifications and contract language. Many of the original specifications were based on grouting methods, and numerous misconceptions have followed the method. The Deep Foundations Institute (DFI) has been the leader in debunking the mystique that has hovered over the method and attempted to standardize the industry through publication of the manuals describing the method and how it should be inspected. DFI should be applauded for taking the lead and producing a reference document that can be used to educate the specification writers, designers, inspectors, and owners. It must be must appreciated that there have been other organizations that would not acknowledge ACIP piles as a legitimate member of the deep foundation family. Some consultants and designers have gone to the extreme of making it policy to not recommend the method for use. This presentation is one practitioner's view of the causes of problems as they can be traced back to the contractual conditions. It is intended to provide a broader and different perspective than those provided by the technical specialists. It does not necessarily reflect the position of the DFI or any of the organizations associated with the ACIP pile industry. It is intended to further the spirit of partnering on every ACIP pile project, to further the acceptance and promote the use of this unique system, for the benefit of all the parties. It should be recognized, however, that all of the participants can and do play a role in getting a project into trouble. My view is that projects that get into trouble usually have an early flaw that leads the project to the edge, and the project participants blindly follow the original mistake right over the cliff like lemmings. This instinctive reaction may be a survival tactic by going along with the group, because any one party that departs from the program or shows a position of weakness is a candidate for sacrifice.

Jan 1, 1997

By William E. Souder

The behavioral accident simulator (BAS) is a computer program that can be used to simulate accident situations. It demonstrates how the potential to have an accident grows or diminishes as a result of changes in various environmental, organizational, and behavioral factors. It calculates the number of fatalities that may result from various conditions and graphically displays these data. The BAS is useful for studying systems of accident causes, for demonstrating the various ways to diminish fatalities, and for training employees. This Bureau of Mines report provides the detailed instructions needed to use the BAS.

Jan 1, 1988

By Stanley M. Moos

The Pueblo Viejo gold/silver mine, located in the Dominican Republic, started production in early 1974 processing ores averaging 4 g/tonne gold and 20 g/tonne silver at a rate of 7,250 tonnes/day. The ore milled is a silicified siltstone with average work index of about 8 that occurs as an extensive oxide capping of a primary sulfide orebody. The sulfide ores are refractory to conventional treatment process and extensive research work is now in progress to develop a treatment process for them. The ore deposit has a long history having been mined by the indigenous Arawak Indians (for some time in the early sixteenth century) prior to the arrival of the Spanish and then by the Spaniards. In the early 1950?s, Italian engineers attempted to process the sulfide ores. Mining by the Indians and Spanish was abandoned because of low grade and little coarse gold in the oxide ores and by the Italians because of the refractory nature of the sulfide ore. In 1969, Rosario Resources geologists discovered that there existed sufficient reserves of oxide ore for a viable mining operation and accordingly, the plant was designed, built and brought into production.

Jan 1, 1979

By Xiang Zhang, Junjie Liu, Zhibo Tong, Langsha Shao, Guojun Ma

The aqueous mineral carbonation process that leaching alkaline earth metals from industrial residues by ammonium salt and carbonation thereafter is one of the potential technologies for CO2 sequestration. In this paper, the effect of particle size of waste slag on the leaching rate of metals under a microwave field and effect of microwave irradiation on the carbonation process were investigated. It was found that the initial leaching ratio of Ca decline seriously with the particle size of EAF slag increasing, and the Ca leaching ratio is relatively low during 120 min leaching. The lower leaching ratio of Ca with large particle size is due to the existence of a silica product layer produced on the surface of calcium silicates. Moreover, due to the microwave irradiation, the leaching ratio of calcium and the crystallization rate of calcium carbonate increase, though the particle size and distribution range of calcium carbonate reduce.

Mar 1, 2018

Under the Bureau of Mines Research Contract Number H0252071, Foundation Sciences, Inc. has compared the relative effectiveness of roof bolts installed at an angle over the rib with that of bolts installed vertically at the rib side, The information gathered during this investigation was sufficient to supply supplementary information on the mechanics of roof support systems and the general acceptability of field instrumentation methods. During the 140 days of field investigation, 235 bolts were installed, 45 inclined and 190 vertical, in two adjacent intersections. Of these 235 bolts, 30 were in-stalled with load cells and 38 were tested for anchor capabilities. In addition to this instrumentation, the deformation of the opening was measured by convergence meter on 9 lines throughout the two testing areas, and a borescope and photo-elastic gauges were utilized to obtain information on the roof action beyond the surface.

Jan 1, 1977

By W. A. Dixon Edwards

Gravel deposi ts in the Edmonton region are unique in their diversity in origin and age. The deposits were described first around the turn of the century (Dawson and McConnell 1896) . Among the many more recent in vestigations are works by Rutherford (1936), Shelley and Associates Limited ( 1977) and the City of Edmonton (1978) .

Jan 1, 1984

By C D. Strickland

Western Australia (WA) has been a significant world producer of titanium minerals (rutile, ilmenite and leucoxene) and zircon for over 55 years. In 2010, despite global difficulties, WA accounted for 12 per cent of world production for zircon, ten per cent for ilmenite, and eight per cent for rutile. With downstream processing, titanium minerals (ilmenite, rutile, leucoxene) and zircon exports for 2010 were valued at $511 M (Department of Mines and Petroleum, 2010).Production is dominated by two areas of the Perth Basin, namely the Eneabba and the Bunbury-Capel regions, which are located 240 km north and 200 km south of Perth respectively. Mineralisation is within Cenozoic beach or near shore dune deposits at three broad altitudes related to the present coastline, and two older higher sea-level still-stands. The titanium-zircon minerals presumably were derived from the underlying Mesozoic sediments of the Perth Basin. Contrary to expectations, age dating suggests that the ultimate source of most of this mineralisation was not the adjacent Yilgarn Craton. With the cooperation of industry, the Geological Survey of Western Australia has mapped all known significant titanium-zircon mineralisation within the Perth Basin. This mapping has identified ‘strategic mineral resource protection areas’ that should be set aside for future mining, ‘sterilised’ and ‘mined’ areas that generally do not restrict land use options, and ‘possible strategic resource areas’ which have exploration potential for hosting titanium-zircon mineral deposits.The Perth Basin is currently undergoing rapid residential and industrial development. By informing all stakeholders of the locations of potential mining areas, the titanium-zircon mapping has the ability to reduce future land use conflicts, and facilitate sequential land use planning. Appropriate planning measures are being implemented to ensure that the Western Australia’s titanium-zircon minerals industry remains strong and viable in the future.

Oct 5, 2011

By T. Koulomzine, R P. Jaeggin

The claims now held by Mount Wright Iron Mines Co. Limited were acquired by staking in 1956, 1957 and 1958, i.e., some time after the major deposits of the Quebec Cartier Mining and Normanvi!le Mining Co. (formerly Quebec Cobalt & Exploration Ltd.) were already discovered and partly outlined. The choice of the location of the Mount Wright hold-ings was governed simply by the -availability of ground still open to staking and by its proximity to properties held by major iron companies. Mount Wright Iron Mines had no previous knowledge of the geology and no aeromagnetic results were available to it to guide the choice of areas to be staked. In order to explore the newly ac-quired claims it was decided to make a grid of widely spaced magnetic profiles on the ground rather than use aeromagnetics. This afforded the possibility of making some geological observations simultaneously with the geophysical measurements.

Jan 1, 1961

By Qingyu Deng, Shiwei Ma, Wang Hua, Guibao Qiu

"The flow properties of the blast furnace slag bearing high TiO2 at high temperature like the viscocity may change a lot due to the formation of the carbonitride inside, causing serious problems on the separation between the metal and the slag. Therefore, the critical condition of the formation of Ti(C,N) in blast furnace is vital importance for the ironmaking process with iron ore bearing titania. In this study, the formation of Ti(C,N) in blast furnace and the influences of various factors on the Ti(C,N) formation are investigated by FactSage. It is found that the mass of Ti(C,N) would reach the maximum at 1480 oC, and the product is mainly TiN below 1620 oC, while it is mainly TiC above 1620oC. The order of the factors by the importance from strong to weak was: temperature, the content of TiO2 in slag, basicity of slag, the content of MgO and Al2O3.IntroductionThe titanium dioxide (TiO2) in iron ore bearing titania will be partly reduced by carbon to titanium carbonitride (Ti(C,N)) in blast furnace, causing serious problems on the separation between the metal and the slag because of the change of flow property. Therefore, the critical condition of the formation of Ti(C,N) in blast furnace is vital importance for the ironmaking process, especially for the smelting of iron ore bearing titania. Extensive experimental data in regard to the formation of Ti(C,N) has been reported in numerous papers[1-6]. However, only some discrete data can be obtained by experiment, and it is difficult to detect the mass of Ti(C,N) in slag. In addition, the experiment is difficult to be proceeded when the temperature is above 1600oC. Therefore, it is very difficult to make clear the critical condition of the formation of Ti(C,N) by experiment."

Jan 1, 2012

By R. E. Miller

Accelerometers and pressure transducers mounted in suspension components can be used to monitor the ride of haulage trucks. Presently, it is difficult to tell what caused a jolt to the truck using either pressure or acceleration data alone. When information from a Global Positioning System is recorded at the same time as shock pressures or acceleration data, then the exact location of an event can be determined. Mine management can then determine what caused the jolt to the truck.

Jan 1, 1999