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By P. R. Clark, M. D. Gleghorn

"IntroductionAt TransAlta Utilities Corporation's Highvale Mine, located west of Edmonton, Alberta (Fig. I and 2), dragline stripping has proved to be a practical and economical method of overburden removal and future plans have been based upon the continued use of draglines (Fig. 3) as the major stripping equipment (Williams, 1979, Nikols et al., 1986). However, long range planning has shown that the capacity of draglines alone will be exceeded in the early 1990s as mining progresses into deeper overburden cover (Tapics, 1983). Strip ratios will increase from I.3 bank m!/ t of coal in 1985to 4.5 bank m3 / t in 1995. During this period the depth of overburden will increase substantially and the areas to be mined will be characterized by weak soils including glacially displaced overburden. This increased overburden depth in relatively weak soils will make it impractical to _continue side casting by draglines without prestripping in advance. In 1983, a major investigation was initiated to determine what additional overburden removal equipment was appropriate to the Highvale operations, and recognizing the long delivery times of this major equipment. when it would be required. This paper describes studies and tests which were undertaken in 1983 and 1984 to select prestripping methods and equipment for the future operation of the mine.Previous planning studies have shown that with the current burn schedule and with the economies of progressing from low cover to high cover, as has been practiced in the past, overburden volumes will exceed the capacity of the existing draglines in the early 1990s (Fig. 4). These previous studies had placed reliance on (I tandem dragline operation for future overburden removal requirements up to a depth of 45 m throughout the Highvale Mine. New drilling together with the associated geotechnical studies and some detailed planning on the practicality of using tandem draglines, created concerns about their universal application. Even without considering geotechnical conditions there was a depth limitation to tandem dragJines and substantial prestripping would be required to achieve the ultimate depths."

Jan 1, 1987

By K. W. Edwards

The formulation of a theoretical basis for the evaluation of in-situ coal through the use of geophysical logs is outlined. This involved the development of an approach to the interpretation of resistivity in environments having multiple conductive and non-conductive components. Utilizing this approach and other conventional interpretation techniques, a program was developed yielding accurate determinations of the in-situ percentages of coal, water and ash for the evaluation of coal deposits. Basic information obtained from the CWA program can be utilized in numerous aspects of total mine planning . Some examples of the practical application of this method are included.

Jan 1, 1978

By Alfred Guenkel, Kyle Marte, K. Nikolaisen

"The INCO SO2/air process was patented by INCO in 1985 (Borbely, Devuyst, Ettel, Mosoiu & Schitka, 1985). Well over 80 mining operations worldwide are using this process to oxidize cyanides to cyanates in the tailings from gold, silver and copper mining operations. Though it is possible to supply sulphur dioxide (SO2) in either gas or liquid form, the majority of these SO2/air operations use sulphite-based salts as the ‘SO2’ equivalent reducing agent. This is probably due to the lower capital cost, safety concerns with, and availability of liquid SO2. Sodium metabisulphite (SMBS) is commonly employed, and its cost is an order of magnitude higher than that of sulphur. The increased capital expenditures (CAPEX) for a sulphur-burning SO2 gas plant could have a pay-back of less than two years. In addition, a SO2 gas plant offers potential for significant heat recovery from the sulphur burning process. In terms of safety, the SO2 gas plant only requires the storage of relatively benign sulphur and the site inventory of SO2 will be limited to the plant gas inventory. Furthermore, a SO2 gas plant will not trigger the US Clean Air Act Section 112(r) accident prevention regulations, as may be the case for liquid SO2.Most existing mining operations using ‘SO2’ are gold operations, but in recent years there has been an increased interest in larger sulphur dioxide gas plants for hydrometallurgical facilities that employ leaching of cobalt/manganese minerals or precipitation of manganese/iron (e.g. Tenke Fungurume and Boleo).This paper discusses the different processes which require SO2 as a reducing agent and compares the capital and operational costs of a SO2 gas plant to conventional process alternatives using sulphite-based salts or liquid SO2.The heart of the SO2 gas plant is the sulphur furnace. The most economical way to produce SO2 is by combustion of sulphur in air producing up to 19.5 vol% SO2. Examples of large and small sulphur furnaces are discussed in terms of design, operation, and impacts on operational costs.The SO2 gas produced in a sulphur-burning plant has to be contacted with the liquor to be reduced. The choice of gas-liquid contacting device is important, and two contacting devices are discussed: 1) Gas sparging into the bottom of leach tanks (high, nearly constant, back pressure due to liquid head) and 2) absorption columns (low gas-side pressure drop)."

Jan 1, 2014

By M. S. Diederichs, G. Walton

"Developments in understanding the brittle fracture of rock over the past two decades ultimately led to the acceptance of a cohesion-weakening-friction-strengthening model as an appropriate strategy for the modelling of spalling using a continuum approach. This strength model has been used to replicate observed failure depths and geometries for a number of case studies in the literature, most notably the AECL Underground Research Laboratory in Manitoba. One thing which these case studies typically ignore, however, is the influence of rock dilatancy on the evolution of brittle failure. Physically, this phenomenon is the volumetric expansion of the rock due to fracture opening; numerically, this phenomenon is captured by the flow rule, which is often characterized by the dilation angle, ?. Accurately modelling rock dilatancy in conjunction with strength evolution is necessary both to predict the magnitude and distribution of ground displacements, as well as the exact depth and shape of the fracturing zone. Both of these factors can have significant implications for support design. This paper is focussed on presenting some of the recent developments in this field in the context of a number of numerical modelling case studies. Initially, a new model for the dilatancy of brittle rock is presented, as well as some representative data and model parameters for different rock types. Next, several case studies of highly stressed tunnels and shafts are presented. The results of continuum numerical models are presented to demonstrate the ability of the back analyses to match observed in-situ measurements and obtained. The predictive capabilities of the material model are also highlighted for cases where sufficient “a priori” information (such as laboratory compression testing data) are available. The issues of model nonuniqueness and strain-localization/bifurcation are also addressed."

Jan 1, 2015

By J. Budac, R. Kofluk, D. Belton, M. Sjogren

A series of tests were performed to determine the flammability limits of mixtures of oxygen, ammonia, steam and nitrogen, over a solution, in a sealed autoclave. The partial pressures of ammonia and oxygen in the vapour space were varied by adjusting the character of the solution and by adjusting the oxygen concentration in the oxidant gas respectively. The data shows that flammable conditions can be minimized by controlling the operating temperature, reducing the ammonia content in the solution, increasing the concentrations of Ni, Cu and Zn in solution and keeping the % oxygen in the gas phase less than 15.5. Observations were also made that suggest that the presence of an aerosol in the vapour space may hinder ignition.

Jan 1, 2004

By G. Gabra, M. Nagamori, J. J. Panneton

"RESUMELa calcination contrôlée de 10 serpentine permet de produire de 10 magnésie active. Le degré de I'activation est mesure par 10 solubilité du magnésium dans les acides faibles tel que I'acide acétique, La serpentine contenue dans les résidus d'amiante du Québec peut donc être activée par calcination. Le teneur en magnésie active des rejets d'amiante calcinés est fonction de divers paramètres: température, temps de calcination, granulométrie, etc. Les rejets d'amiante de différentes provenances démontrent des comportements thermochimiques différents qui sont étudiés dans Ie présent travail au moyen d'ATD, de TG, de la diffraction des rayons X et de la lixivation par l'acide acétique. On constate qu'un maximum d'environ 80% de la magnésie totale peut être activé dans certains rejets d'amiante du Québec et Ie degré d'activation dépend de la provenance.vIntroductionOn sait depuis longtemps que la serpentine, Mg3Si2O5(OH)4, un silicate hydroxylé de magnésium, devient amorphe lorsqu'elle perd de I'eau d'hydratation entre 600 et 700 °C. La serpentine ainsi calcinée est alors dissociée en magnésie et en silice. Cette magnésie, dite active, est soluble dans un acide faible ou même dans les solutions de sels d'ammonium.Plusieurs precédés chimiques ont été proposés afin d'extraire sous forme de composés magnésiens la magnésie de la serpentine. La plupart de ces procédés comportent une activation par calcination de la serpentine préalablement à une Iixiviation par un acide ou par une solution d'un sel d'ammonium.Malgré la contamination par Ie fer et par d'autres éléments, les compositions chimiques des rejets de différentes mines d 'amiante du Québec, présentées au tableau 1, sont très proches de la serpentine typique. Puisque Ie degré d'activation de la magnésie varie grandement d'une serpentine à I'autre lors de la calcination, la première étape de la recherche sur la transformation chimique des rejets d'amiante du Québec se résume à une étude de leurs comportements thermochimiques."

Jan 1, 1982

By Rodney A. Cooper

The Mary River iron ore deposits were discovered in the 1960?s. The high quality of the deposits was immediately evident, and drilling programs were successful in defining a resource adequate for supporting a feasibility study. Through a combination of ownership, market and political forces, the deposits were not developed. Having missed the window of opportunity, the project remained dormant for over three decades. Baffinland Iron Mines Corporation, with its 100% ownership of the Mary River deposits, began trading publicly in 2004. Modern exploration and metallurgical test work began in 2004 and has continued in 2005 and 2006, resulting in total expenditures during this period of almost C$60 million. In May 2006, an engineering team lead by Aker Kvaerner E&C, a division of Aker Kvaerner Canada Inc., completed a scoping study based on the first of five identified deposits. Highlights of that study include direct shipping of high quality lump ore to Europe over a 34 year mine life at a production rate of 10 million tonnes per annum, based on an indicated resource of 309 million tonnes at 66.1% Fe and an inferred resource of 28 million tonnes at 65.9% Fe. Capital costs were estimated at C$1.5 billion. Using iron ore prices approximately 36% below that of the 2006 market, a pre-tax internal rate of return of 15% was estimated assuming equity financing. Payback on initial capital was 5.9 years. The pre-tax life-of-mine cash flow was estimated to be C$6.3 billion. As a result of this study, Baffinland initiated a Definitive Feasibility Study, under the management of Aker Kvaerner, which is scheduled for completion in December 2007. This paper touches on the geology of the deposits, the current resource and the outlook for expansion. Project permitting, construction planning, logistical challenges and ocean shipping considerations are discussed, providing a current perspective on the project scale, scope and timeline for commercial production. In addition, an overview of the Company?s bulk sampling program will be provided.

May 1, 2007

By M. Goto, F. Kubota

"In this study, we show the successful separation of rare earth metals, which are indispensable elements for the high-tech industry, from a solution containing a metal mixture by using a liquid-liquid extraction and liquid membrane based on ionic liquids. We employed newly synthesized N, Ndioctyldiglycol amic acid (DODGAA) as an extractant for rare earth metals. The DODGAA exhibited a high affinity for rare earth metals such as Y, Nd, Eu and Dy and the extraction efficiency was greatly enhanced in ionic liquids (ILs). Furthermore, stripping of the metals was readily achieved by using an acid solution. INTRODUCTIONRare-earth metals have important applications in cutting-edge technologies employed in the electronics, information technology, and automobile industries. As Japan does not have many natural metal resources, maintaining a steady supply of imported rare-earth metals is important. The total amount of rareearth metals imported into Japan was 19,000 tons/year in 1996, and this amount increased to 40,000 tons/year over the following decade (Kramer 2010). Japan is now one of the world’s major importers of rare-earth metals (Kramer 2010). However, more than 90% of the rare-earth metals imported into Japan come from China, the world’s leading supplier of rare-earth metal resources, due to their low costs. This situation made us realize the importance of a second resource of rare-earth metals: “urban mines” or discarded electronic waste. Rare-earth metals are generally separated from their natural ores by solvent extraction. However, since urban mines have different metals and the concentrations of rare-earth metals are usually low, highly efficient separation and recovery methods are required for rare-earth metals.Recently, ionic liquids (ILs), which are molten salts at room temperature, have attracted considerable attention since they are novel, environmentally friendly solvents (Kubota & Goto, 2006; Han & Armstrong, 2007). The use of ILs in liquid-liquid extraction of rare-earth metals has been reported (Kubota et al., 2012). In some cases, the IL-based systems showed better extraction ability and selectivity than those showed by the conventional organic solvent extraction systems(Nakashima et al., 2003, 2005; Hirayama et al., 2008; Fang et al., 2012). Therefore, more efficient solvent extraction processes by using ILs can be developed. In this study, we investigated solvent extraction processes in which ILs are employed and discuss the possibility of using ILs in the separation and recovery of rare-earth metals from electronic waste."

Jan 1, 2012

By J. Olson

"A model was developed to use near-infrared (NIR) analysis of pulverized ore samples to estimate the recoverable gold content for ores from the Barrick Cortez Hills underground mine. Current routing practices use a ratio of the cyanide soluble gold content and fire assayed gold (CN/FA) to classify ores as oxide or refractory. Prediction accuracy of the NIR model was equivalent to the CN/FA ratio. Prediction accuracy was improved by combining the CN/FA ratio and the NIR spectra. Bootstrap validation estimates the root-mean-square error to be 9.92% with an estimated r-squared value of 0.893. This model will allow more accurate estimates of the variability in recoverable gold content throughout this mine. These data will aid in building an improved geo-metallurgical model or in making better informed routing decisions during the production cycle.INTRODUCTION The contained gold of an ore available for cyanidation is often related to subtle variations in the mineralogy. It is difficult and expensive to collect enough mineralogical information in order to predict how the variable mineralogy will impact the metallurgical results and project economics throughout the life of the mine or mill. Near-infrared spectroscopy may be an effective tool to rapidly and inexpensively collect discrete, quantitative mineralogical data for minerals that contain transition metal oxides, metal sulfides with semi-conduction properties, rare earth metals, and some chemical groups having di-pole covalent bonds such as carbonates, sulfates, and various types of clays (Hunt, 1977). Near-infrared spectroscopy can be a powerful tool for geo-metallurgical characterization of deposits where the presence of these minerals has direct or indirect relationships to metallurgical results such as grindability, regent consumption, or recovery. Near infrared spectroscopy is a rapid analysis that measures the intensity of reflected light in the near-infrared spectrum. The ranges for the ASD-Panalytical units used in this study extend through the visible spectrum and into part of the UV spectrum, reporting reflection by wavelength from between 350 nm to 2500 nm. Absorption peaks visible in this range are a result of interactions with outer valence elections or chemical bonds. The location and intensity of the peaks vary depending on the chemical composition and crystal structure of a solid indicating the presence and abundance certain minerals (Hunt, 1977; Clark, 1984)."

Jan 1, 2017

By David G. Baskin

"THIS DEPARTMENT is unique in that it operates in the production stream and also provides an essential service. Its operating function consists of scheduling an ore train to haul 10,000 tons per day over 17.1 miles of track and switching all incoming and outgoing rail equipment on 2.2 miles of track at the minesite and 6.2 miles of track at the metallurgical site. The service it provides is traffic control of all incoming commodities and all outgoing concentrates, metals and acid by rail and truck, even extending to port and ship control for overseas shipments (Fig. 46). Although they cover many miles, the railroad and traffic department employees operate very efficiently, as indicated by the following organizational chart:Railroad and Traffic Superintendent ................ 1Railroad Supervisor .............................................. 1Assistant Railroad Supervisor ........................ 1Track Foreman ...................................................... 1Trainmen ............................................................... ... 4Switchmen ............................................................... 4Trackmen ................................................................ 10Traffic Supervisor ................................................ 1Clerk Steno ............................................................ 1Clerks ...................................................................... 3"

Jan 1, 1974

By E. L. Bruce

Introduction The Outokumpu copper mine is situated in eastern Finland, 50 kilometers west of the city of Joensuu or 225 kilometers directly north of the city of Viborg (Viipuri), which is situated at the eastern end of the gulf of Finland (Figure 1). The ore-body was discovered in 1910 by Dr. Otto Trüstedt after two years of careful, scientifically-directed, search. During the early period of development of the mine, the ore was treated locally and the copper re-covered by an electrolytic process. Now the ore is concentrated by tables and by flotation. The concentrates are shipped to Germany for refining. In 1929 the mine produced 150,000 tons of ore from which between 20,000 and 25,000 tons of flotation concentrates containing 20 per cent copper were produced. Profits in 1929 were approximately half a million dollars, but the present price of copper will affect very seriously the profits for 1930. The ore reserves are given as between 7 and 8 million tons (1). The grade of ore is stated to be 4 percent to 6 percent copper, with a little zinc.

Jan 1, 1931

By Y. Tang

"Rare earth elements (REEs) have many key applications in traditional and advanced technologies. A shortage of several critical REEs is expected due to the discrepancy between the availability of REEs from REE deposits and the REE demand from the market. REE recovery and separation from secondary resources such as uranium wastes and recycled materials might help balance the shortfall in a cost-effective way. This paper presents data concerning the recovery of heavy REEs (HREEs) from uranium raffinate. It also discusses the design, commissioning, and operation of a solvent extraction pilot plant for the separation of REEs.RÉSUMÉ Les éléments des terres rares (ÉTR) trouvent de nombreuses applications importantes dans les technologies classiques et de pointe. On prévoit une pénurie de plusieurs ÉTR critiques en raison des divergences constatées entre la disponibilité des ÉTR provenant de gisement d’éléments des terres rares, et la demande d’ÉTR sur le marché. La récupération et la séparation des ÉTR à partir de ressources secondaires telles que les déchets générés par le traitement du minerai d’uranium et les matériaux recyclés pourraient contribuer à équilibrer cette pénurie de manière rentable. Cet article présente des données relatives à la récupération des ÉTR lourds (HREE, de l’anglais heavy REEs) à partir de raffinat d’uranium. Il aborde également la question de la conception, de la mise en service et de l’exploitation d’une usine pilote d’extraction par solvants pour la séparation des ÉTR INTRODUCTIONSignificant amounts of strategic specialty heavy rare earth elements (HREEs) are present in waste streams in Saskatchewan uranium operations. Selective precipitation including neutralization, oxalate, and double-salt precipitation, as well as sulfide precipitation, ion exchange (IX), and solvent extraction (SX) are commonly used technologies for the recovery and purification of rare earth element (REE) solutions. REE oxalate precipitation can effectively remove Fe, Al, Ca, Si, and other impurities by taking advantage of the solubility difference between REE oxalates and impurities in the acidic solution (Xu, 2005)."

Jan 1, 2018

By The Staff

THE property of McKenzie Red Lake Gold Mines, Limited, consists of eleven claims located on McKenzie island in Red lake. The mine is about 4,Y:l miles by water from the Howey townsite on the same lake, and about 95 miles north of Kenora, Ont. (see Figure 4). Mail and express are flown-in daily, winter and summer, from Sioux Lookout, Hudson, Kenora, and Winnipeg. All heavy supplies are freighted-in during the summer over a water route, using four marine railway portages, from Hudson, Ont., a distance of about 180 miles. During the winter, freighting over the same route is clone by tractor if necessary, but costs are three to four rimes the summer rate. Due to these conditions, large inventories of supplies must be kept on hand, varying from a spring minimum of $45,000 to a peak of $110,000 early in November. The average cost of all freight brought in from steel during 1937 was $0.01 per pound.

Jan 1, 1938

By T. G. Carter

"Damaging seismicity associated with deep faulting in both mining and civil excavations not infrequently occurs without warning, and often before proper mitigation measures have been put into place. Severe squeezing is also a common problem for excavating through deep major faults. While both problematic conditions are difficult to predict and characterize, there is often a need at pre-feasibility and feasibility level to more reliably estimate the possible level of risk posed by such geologic structures. This paper introduces some structural geologic techniques that have potential application for both mining and civil applications for aiding forewarning of the extent of these types of problem.INTRODUCTIONEncountering adverse faulting at depth in deep excavations, whether for mining or civil purposes can create serious economic and safety impacts. For deep mines or for deep tunnel projects, measures are available for aiding prediction of the extent of possible influence that large scale faults could create, but these techniques are rarely if ever applied as part of routine site investigation programs, or even as part of risk assessment evaluations. Several well established structural geologic methods of palao-history reconstruction have potential application for aiding forewarning of the extent of these types of potential problem by allowing estimates to be made of:• controlling stress orientations that might engender reactivation movement;• principal stress magnitudes that could lead to failure initiation, and• probable mechanisms of fault deformation - brittle (bursting) or plastic (squeezing).This paper explores several structural geological and rockmass characterization techniques that have application for unravelling fault structure of importance to deep engineering projects. Their application for mining or tunnelling purposes is advocated in conjunction with conventional rockmass characterization assessment approaches using GSI, RMR and/or Q to aid early recognition and definition of potential adverse ground condition behaviour associated with intersection of significant faulting at depth."

Jan 1, 2015

By S. Castro, L. Gutiérrez, L. Uribe

"Use of lime in seawater as a pyrite depressant decreases Mo recovery in flotation of Cu- Mo sulfide ores. When technology that uses sodium metabisulfite (MBS) to depress pyrite is applied, the process is carried out at pH 6.5–7.5, the range where Mo recovery is higher than the usual pH 11.0–12.0 when lime is applied. Redox conditions and chemical reactions involved in depression mechanisms of pyrite by MBS, or sodium sulfite, in seawater are investigated and discussed based on the acidifying effect of MBS, oxidation of sulfite ions by dissolved oxygen, and the role of catalyst of some metal cations (e.g., copper ions) adsorbed on pyrite’s surface.RÉSUMÉ L’utilisation de chaux dans de l’eau de mer comme agent déprimant de la pyrite réduit la récupération de molybdène (Mo) dans la flottation de minerais sulfurés de Cu-Mo. Lorsque l’on applique la technologie utilisant du métabisulfite (MBS) de sodium comme agent déprimant de la pyrite, le procédé se fait à un pH de 6,5 à 7,5, gamme dans laquelle la récupération de Mo est supérieure au procédé habituel utilisant un pH de 11,0 à 12,0 lorsque l’on applique de la chaux. Les conditions de réduction-oxydation (redox) et les réactions chimiques impliquées dans les mécanismes de dépression de la pyrite par le MBS (ou sulfite de sodium) dans de l’eau de mer sont étudiées et débattues sur la base de l’effet acidifiant du MBS, de l’oxydation des ions sulfites par de l’oxygène dissous et du rôle de catalyseur de certains cations métalliques (par exemple les ions de cuivre) adsorbés à la surface de la pyrite. INTRODUCTIONThe copper industry is aware of the difficulties of floating Cu-Mo sulfide ores in seawater. Molybdenum recovery is partially depressed when lime is used to reject pyrite. In plant practice, sodium metabisulfite (MBS) has been demonstrated to be the most promising option for replacing lime in seawater."

Jan 1, 2017

By C. Cutts, K. Wheatley

The Dragon Lake Zone (uranium prospect) comprises a N160º trending vein that is approximately 110 m long, up to 5 m wide and from 1 to 40 m high. The zone is mostly within altered sandstone of the Fair Point Formation, the basal unit of the Paleoproterozoic Athabasca Group, but it also extends downward (up to 3.5 m) into basement rocks that occupy the northerly trending Maybelle River Shear Zone (MRSZ). This subvertical shear zone separates graphitic paragneiss and weakly deformed granitoid rocks to the east from non-graphitic paragneiss and foliated granitoid rocks to the west. The Dragon Lake Zone cuts across both the MRSZ and N060º-N070º-trending cross-faults that offset the shear zone but not the mineralized vein, which contains values up to 54.5% U over 50 cm core length. Strong chloritization occurs in graphitic paragneiss and sandstone adjacent to mineralization. Silica was depleted from the basement rocks and redeposited at the borders of the 5-15-m-wide alteration zone, as well as within overlying sandstone of the Manitou Falls Formation. There are minimal alteration effects in the overlying Lazenby Lake Formation. Geochemistry shows that the alteration zone in the Fair Point Formation is highly anomalous in metals, most notably in Ni, As, U, Pb, Co, and B. Clay within this zone is illitic and Fe-rich chlorite is also present. Brittle deformation is not as widespread or as well developed in the Fair Point Formation as it is in the overlying Manitou Falls Formation, which is extensively brecciated and contains some anomalous metal values.

Jan 1, 2013

By P. Babak, E. Insalaco, O. Babak, P. Henriquel

"Detection of outliers is an important primary step in geomodelling. Geological datasets often contain errors due to problems such as measurement device limitations and recording glitches. In this paper, a robust Mahalanobis distance–based approach is successfully applied to particle size distributions of the Joslyn lease, an oil sands development site near Fort McMurray, Alberta, Canada. Automatic outlier detection and geological review were combined. Outliers from the Mahalanobis distance approach were compared with their respective core photographs to determine if laboratory measurements and facies classification were correct. A checking procedure for laboratory technicians is proposed.RÉSUMÉ La détection des valeurs aberrantes constitue une étape primaire importante de la modélisation géologique. Les ensembles de données géologiques contiennent souvent des erreurs en raison de problèmes tels que les limitations des instruments de mesure et des pépins d’enregistrement. Dans le présent article, une méthode robuste basée sur la distance de Mahalanobis a été mise en oeuvre avec succès aux granulométries du bail minier Joslyn, un site de sables bitumineux en développement à proximité de Fort McMurray, Alberta, Canada. La détection automatique des valeurs aberrantes a été combinée à une étude géologique. Les valeurs aberrantes de la méthode de la distance de Manalanobis ont été comparées avec leurs photographies respectives de carottes de forage afin de déterminer si les mesures en laboratoire et la classification des faciès étaient correctes. Une procédure de vérification pour les techniciens de laboratoire est proposée."

Jan 1, 2015

By Sib N. Mukherjee

Main ventilation fans are used in all the mines and they run continuously 24 hours a day and 365 days in a year. Any improvement in their performance can lead to considerable power saving. The basic principle for selection, operations, and related measures are discussed in brief in the paper. The contributions of different elements of mine fan on its performance are discussed in brief. The means to improve efficiency of a running fan is also discussed and the importance of saving even 1 Kwh is elaborated. It is found that the cost of the energy saved may even permit a replacement fan to be procured in a few years time.

May 1, 2007

By A. Ashrafi

The electrochemical deposition of polypyrrole coating on different pretreated aluminum-alloy 7075 substrates was carried out using cyclic voltammetry, The pretreatment of specimens consisted of mechanical polishing and/or electrochemical etching, In the latter case, an aqueous solution of phosphoric acid and ethanol was used, The electrodeposition solution was 0,25 M pyrrole and 0,1 M oxalic acid in double-distilled water, The cyclic voltammetry scan rate used was 700mv/s, Morphology of the coatings was examined using scanning electron microscope (SEM), Using the Tafel experiment, corrosion resistance of the coated substrates was investigated in 0.1 M NaC1 solutions, Results obtained revealed that electropolymerization of polypyrrole on 7075 aluminum alloy would increase the resistance against corrosion in 0,1M NaC1 solution, Also it was observed that, compared with mechanical polishing, electroetching pretreatment would be more effective.

Jan 1, 2005

By The Staff

WE were requested to make a digest of our original grinding report, Fine Grinding Investigations at Lake Shore Mines. This digest is much easier to read than the original report, but it lacks the experimental 'evidence' found in the first report which, in many cases, is much more interesting and educational than the conclusions derived from it. In the course of rewriting the paper, we noticed several new angles on the test data which had not occurred to us previously. From the data included in the report and other tests not published, calculations were made which indicated a line of new test work. These tests, among other things, more than suggest a technique for designing the length of mills, the position and number of classifiers, and the total loads a mill should carry.

Jan 1, 1941