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By F. Ford, J. Dong

"Laboratory and miniplant testwork was carried out to reject uranium from an Iron Oxide Copper Gold (IOCG) deposit that contains an average of 60-70 ppm uranium with high variability. The dominate copper bearing mineral is chalcopyrite with minor bornite and trace covellite. The main gangue minerals are iron-rich chlorite, quartz and magnetite. The main uranium-containing mineral is uraninite (UO2). Downstream processes require the maximum uranium level of no more than 80 ppm in final copper concentrate.Mineralogical examination reveals that uraninite particles are finely disseminated with grain size of less than a few microns in the deposit requiring fine regrind in order to liberate uraninite from chalcopyrite particles. A lab flowsheet was developed to include ultrafine regrind of the rougher concentrate to the particle size of 80% passing 11-13 µm with up to four stages of recleaning in flotation columns. Finer regrind to 80% passing 5-6 µm may continue to improve liberation but does not decrease uranium level in the final concentrate. In each of the successive recleaning stages by flotation column after fine regrind, uraninite is rejected into the column tailings, with the final copper gold concentrate containing less than 70 ppm uranium from a feed containing 83 ppm uranium. The conceptual flowsheet was further tested in an integrated, continuous miniplant showing average 94% copper recovery with average 74 ppm uranium. The uraninite particles that report to the final concentrate are either locked with chalcopyrite or entrained as liberated particles of less than 5 µm in size."

Jan 1, 2016

By T. H. Patching, M. W. Mikhail

"The gas sorption and emission characteristic of coals are important to the planning and conduct of mining operations. Methane drainage from coal strata can also provide a supply of fuel in certain circumstances. Gas emissions have also created hazards during the handling and transport of coals and the release of gas also appears to be related to the yield of fine sizes during mining and processing operations.This paper summarizes studies at the University of Alberta on the permeability and gas emission of certain bituminous coals. Permeability of 'solid' samples was found to be drastically reduced by confining pressure. An emission index, .P, which has been related to outbursting behaviour of coals, has also been related to the proportion of fine s in cleaning plants. Gas sorption isotherms are dependent on temperature, moisture content, the gas involved and the type of coal and can be approximately expressed by the Langmuir or the Freundlich equations. Sorption values in sections taken across a given seam were similar but considerable differences were found in . P indices in the different coal layers of a seam.IntroductionThe emission of gases, especially of methane, from coal has been a subject of great interest (and sometimes a matter of life and death), to those who dig and handle coal since it was first mined from underground pit s. Many studies and investigations have been carried out on gas occurrences and emissions but our knowledge of the precise mechanisms of gas sorption, desorption and flow from coal is still incomplete. It is the purpose of this paper to review the principal factors involved in these processes and to briefly rep ort some of the results that have been obtained by studies in the laboratories of the Department of Mineral Engineering, University of Alberta, and Coal Research Laboratory, Edmonton, CANMET"

Jan 1, 1986

By Bordeaux Sciences Agro-INRA UMR 1065 SAVE, S. Piutti, E. Benizri, S. Lopez

Ultramafic soils display high concentrations of nickel (Ni) and a number of nutrient deficiencies (e.g. N, K, P). Ni-hyperaccumulator plants have evolved on such environments, developed specific metal homeostasis showing concentrations of Ni sometimes above 1% in their aerial biomass (Baker & Brooks 1989). Alyssum murale, a Ni-hyperaccumulator, is commonly found around the Mediterranean but can grow on non-ultramafic soils as well, with an altitudinal extension ranging from sea level to 2000 m.a.s.l. Rhizosphere bacterial communities associated with Ni-hyperaccumulator plants can differ from those of non-accumulating plants growing at the same site. Among edaphic factors that could influence the phylogenetic structure of the bacterial communities, altitude and metal-bioavailability and in particular nickel could be significant. However, most studies have focused on analyzing soils with techniques that provide little detail about the phylogenetic structure of these bacterial communities present in ultramafic soils. The objectives of this study were to understand the specific changes in the structure of A. murale rhizosphere bacterial community that occur across two gradients: 1°) elevation and 2°) Ni geochemistry, using pyrosequencing technique (454-pyrosequencing of 16S rRNA gene). It was found that the higher the soil chemically-available Ni contents, the higher the relative abundance of Proteobacteria and Actinobacteria. On the contrary, the abundance of TM7 decreased with increasing levels of available Ni. Moreover, Chloroflexi was present with 53 to 77% of relative abundance. These results demonstrate that soil chemically-available Ni drives the bacterial community diversity in the rhizosphere of Alyssum murale regardless the elevation gradient and other different soil physicochemical parameters. These results should now be confirmed in different ultramafic edaphic environments worldwide (e.g. ultramafic lateritic covers) and in the rhizosphere of different hyperaccumulator taxa.

Jan 1, 2016

By D. W. Euler, B. J. Clauzier

"Implementation of an effective energy management system will reduce energy costs without impacting negatively on production.The energy management system must be designed to complement the operation and be integrated with the organization. It must be reliable and easy to use but most important, it must have an accurate and timely feedback reporting system to allow the operation to take appropriate action.Falconbridge Limited was one of the first three companies to be awarded the energy monitoring demonstration program in May 1987. The program is sponsored jointly by the Ontario Ministry of Energy and Ontario Hydro.This paper describes the approach taken by Falconbridge Limited to implement the Onaping Area Energy Management System.IntroductionThe objective of the project was to implement an effective energy management system, capable of reducing energy costs without impacting negatively on production.Energy management systems must be designed to complement the operation and to be integrated with the organization. The system must be reliable and easy to use, but most importantly, it must have an accurate and timely feedback reporting system to allow the operation to take appropriate action."

Jan 1, 1990

By F. J. Munn

"Since 1976, Cardinal River Coal s Ltd. has completed mining in eight pits. In each of these pits, at least one wall has failed, none by design, although not totally unexpected, yet there was no loss of production nor risk to personnel or equipment. Cardinal River Coals Ltd. has been successful in implementing a program to cope with failures and now feels justified in adopting more optimistic design parameters.The wall control program at Cardinal River Coals Ltd. is based on the premise that the walls are going to fail, monitoring is to confirm when. The program consists of monitoring slope movements and piezometric levels as well as structural mapping and visual inspections. In case of excessive movement, the frequency and intensity of the monitoring is increased. If a failure is impending, suitable remedial action is undertaken such as cutting down the crest, building up the toe, depressurization of the wall, artificial support, or a combination of the above. If remedial action is not possible, monitoring permits operations to continue up to near the time of failure.At the design stage, the emphasis is on identifying the potential failure mechanisms and the con sequences of failure. Once the potential failure mechanisms are identified, a monitoring system can usually be employed to give sufficient response time, and providing the consequence of failure is not severe and/ or remedial action can be taken to arrest the movements, then it is practical to mine pit slope s which have a higher probability of failure."

Jan 1, 1985

By Bennett McLaughlin, Gille Brousseau, John F. Cook

"La Mine Bousquet commenced operations in October 1979. Mining has been by underground methods from two main zones which dip steeply to the south , Sub-level stoping methods with following fill are used.The orebody and immediate country rocks are sericitic and highly schistose. The intensity of schistosity varies significantly and poor ground conditions prevail, especially within the orebody,Initially few mining problems were encountered but in May 1981, significant damage occurred. A system of stabilizing pillars was introduced with improved support systems. Predevelopment in ore and pre-drilling of blastholes were reduced with extra footwall development.Damage has continued to occur on a regular basis particularly during the spring thaw. Generally, the adverse conditions have been successfully overcome.IntroductionMost of the mining problems that have been experienced at Bousquet have been caused by poor ground conditions . This pa per describes these conditions, considers the cause and describes the ways in which the conditions have been dealt with . Despite the problems, Bousquet is a successful operation which in 1983 produced 95,000 ozs of gold from 514,000 tons of ore."

Jan 1, 1985

By H. W. Wevers

This paper is the result of an intensive literature search and practical study of the problems experienced by a mining company with the frame cracking of their large-tonnage haulage trucks. It explains the advantages of particular HSLA steels for applications in the welded structures of such equipment. Examples of existing welds in truck frames are analyzed. Modern fatigue models and linear elastic fracture mechanics techniques are explained.

Jan 1, 1978

By N. R. Paterson

"More than a dozen AEM systems are currently being used in the routine exploration for massive sulphides. The systems differ from one another in minor respects, but fall into four main categories: rigid-coupled in-phase/quadrature systems; towed-bird, single-component systems; differential systems; and passive systems.Although field tests are important in demonstrating the performance characteristics of the AEM/airframe assembly (noise-levels, coupling effects, etc.), more meaningful evaluations can be made through physical or computer modelling. The latter approach has been used to compare the response of twelve AEM systems to both vertical and horizontal sheets, simulating a large orebody and a con-ductive overburden respectively. The effects of height changes are also studied.The results demonstrate that each AEM system has its own particular advantages and disadvantages. The relative importance of these is a matter for the geophysicist to judge, on the basis of specific geological and environ-mental information. Data currently available on AEM systems are adequate to permit an objective evaluation of the systems for a particular exploration program."

Jan 1, 1971

By R. M. Bustin

"Extensive deposits of tectonically sheared coal of the Mist Mountain Formation occur in the south eastern Canadian Cordillera. The quality of the coal varies markedly; it is commonly partially oxidized and poor washability characteristics.Oxidation of the sheared coal has been promoted by its fine grain-size and by fractures in adjacent rocks which have facilitated penetration of atmospheric oxygen and circulation of oxygenated waters. Oxidation has resulted in a loss of coking power, a decrease in vitrinite reflectance, and an Increase In oxygen and decrease in carbon content.The relatively low clean coal yields of the sheared coal are primarily the result of the greater volume of mineral matter present, which in turn reflects both the greater susceptibility to shearing of coal with abundant rock partings and the shearing and dissemination throughout the coal of formerly discrete rock partings. The high ash content of some sheared coal seams may be artificial, resulting from the difficulty in distinguishing and separating sheared roof rock and floor strata from the coal seam during mining. There is little variation between the quality of the washed sheared and unsheared coal, with the exception of the somewhat higher ash content of the clean sheared coal compared to clean unsheared coal. This poorer separation of the ash from the organic fraction of the sheared coal is considered to be a product of the large amount of fines present as well as the local formation of aggregates of organic material and ash resulting from plastic flowage of the vitrite and clarite during shearing.IntroductionIn the southeastern Canadian Cordillera, coal seams of the Lower Cretaceous Mist Mountain Formation (Gibson, 1979 were in part sheared and comminuted during Late Cretaceous and Tertiary tectonism . Extensive deposits of sheared coal exist, and even in areas of mild deformation the coal may be locally sheared (Bustin, 1979). The quality of the sheared coal varies notably; it is commonly oxidized even far from the present weathering horizon, and locally has a disproportionately large amount of ash and poor washability characteristics even far from the present weathering horizon and locally has a disproportionately large amount of ash and poor washability characteristics."

Jan 1, 1982

By Pingchao Ke, Zhihong Liu

Fe(III)-As(V) precipitates were synthesized from the Fe(II)-As(V)-SO42--H2O system at 90°C in initial Fe(II)/As(V) molar ratios of 4.0 and 5.0, respectively. The synthesis were carried out by introducing oxygen gas into the system to oxidize Fe(II) ions into Fe (III) ions, and at the same time, adding aqueous sodium carbonate solution into the system to neutralize the acid released by the hydrolysis reactions, with the purpose of keeping the pH constant at 1.5±0.05. The precipitates obtained were characterized by XRD, chemical composition analysis, SEM, XPS, and Raman spectrum. The results indicated that the particles in the precipitates were in the morphology of irregular aggregation with their sizes in the range of about 1–4 µm. The precipitates consisted of scorodite, ferric arsenate and amorphous hydrated ferric oxide, of which amorphous hydrated ferric oxide formulated as Fe(OH)x(SO42-)y. The characteristic XPS peaks of Fe-AsO43- and Fe-O in the precipitates located at 711.8 and 713.3 eV, separately, and the existence of amorphous hydrated ferric oxide led to two series of shake off lines developed over the end of high binding energy of Fe2p XPS. The precipitates were stable in TCLP tests at pH 4.93 for 60 hours with the arsenic concentrations in the leaching solutions being 0.27 mg/L and 0.59 mg/L for the precipitates prepared in the initial Fe(II)/As(V) molar ratios of 4.0 and 5.0, respectively. The tests for the long-term stability of the precipitates were carried out by leaching them for 40 days at 25°C under various media in the pH range from 9.50 to 10.57, and the results showed that the precipitates synthesized in this study were much more stable than those by previous researchers.

Jan 1, 2017

By J. Robitaille, P. Cousin

"Agnico-Eagle Mines Ltd, Laronde Division, is a gold operation processing ore containing copper and zinc. Copper is recovered as a concentrate prior to gold cyanidation.Copper concentrate grade was improved with the implementation of an on-stream analyzer. Further improvements to the copper concentrate grade could be achieved throughefficient zinc depression.High cyanide cost linked to the copper content in the flotation circuit tails, prompted some modifications to the flotation circuit. Economics and environmental issues were considered. A Maxwell cell was retrofitted with an Outokumpu HG cell mechanism stabilizing it's operation. Secondly a flotation column was added to increase circuit capacity.This paper will address flotation circuit operation difficulties, successes and results achieved before and after modifications.RESUMELes Mines Agnico-Eagle division Laronde sont considéré comme étant un producteur d'or. Le minerai révèle toutefois des teneurs appréciables en cuivre et zinc. Un circuit de traitement combinant des étapes de flottation du cuivre et de cyanuration de l'or a été adopte. Le rejet de la flottation est lixivie pour son contenu en or.La teneur moyenne en cuivre du concentre final fut augmentée suite a l'implantation d'un système d'analyse en continu. Une séparation plus efficace de la sphalérite se devra d'être obtenue afin d'améliorer davantage la qualité du concentre produit.Le contenu en cuivre au rejet du circuit de flottation influence directement la consommation en cyanure. Pour cette raison, certaines modifications à la flottation sont devenues nécessaires. Des facteurs d'ordre économique et environnemental ont été considérées. Une cellule existante fut transformée en cellule HG d'Outokumpu, stabilisant son opération, et une colonne de flottation fut ajoutée au circuit afin d'accroitre sa capacité.Le présent document se veut une rétrospective des problèmes d'opération vécus, des solutions apportées ainsi que des résultats obtenus et de leurs implications suite aux améliorationseffectuees."

Jan 1, 1995

By W. A. Plachner, Schiller E. A., S. P. Santiago

"The Monkman Coal Property is located in the Northeast Coal Block of British Columbia. It is divided into the Duke Mountain Block on the north east and the Dip Slope on the west. Together, these areas cover 39,503 ha of coal licences.The property is underlain by Jurassic and Lower Cretaceous marine and continental sedimentary rocks. Economic coal measures are contained within the Gates Formation. Exploration of the property began in the early I970s, with drilling commencing in 1975. To date, 255 holes have been drilled and nine adits have been driven to recover unoxidized coal samples.The property has a geological resource potential of 2.8 billion tonnes of medium and high-volatile bituminous coal. Medium-volatile bituminous reserves, totalling 68.9 million ROM tonnes at an over-all strip ratio of 6.3:1, have been identified in three pit areas in the Duke Mountain Block.Construction start-up will commence when sales contracts are arranged. The clean coal will be exported via the Ridley Island Terminal at Prince Rupert.IntroductionThe Monkman Coal Property is located in the Northeast Coal Block of British Columbia in the southern port ion of the Peace River Coalfield. The coal field encompasses a strike length of 250 km of Lower Cretaceous coal-bearing strata in which 13 companies have identified several billion tonnes of resources and several hundred million tonnes of reserves. Currently, two companies with contracts are in the construction phase, and are scheduled to produce coal by early 1984. Quintette Coal Ltd. has a contract with Japanese steel mills to supply annually 5.0 million tonnes of metallurgical and 1.5 million tonnes of thermal coal. Teck Corporation (Bullmoose property) has a contract to supply 1.7 million tonnes of metallurgical coal annually."

Jan 1, 1983

By C. Paulo, W. N. Wheeler, M. Kalin, M. P. Sudbury

Many researchers have tested the addition of various phosphatic materials, including Natural Phosphate Rock (NPR), to mining wastes. It was assumed that iron in the waste would form FePO4 precipitates, restricting oxygen access to pyrite surfaces and reducing oxidation. Phosphate additions were based on stoichiometry (phosphate mass to sulphide content of waste). Although some interesting, positive results were obtained with low dosages, these were considered accidental, not having followed the expected stoichiometry. In 1991, we began experimenting on tailings and waste rock with NPR, postulating that if chemo-lithotrophic microbes on the mineral surface accelerate oxidation, then heterotrophic (oxygen-consuming) microbes would reduce oxidation. All wastes with NPR produced effluents with elevated pH and low metal acidity. Later, microscopic investigations of the rocks found an organic layer on the mineral surface, which was confirmed by independent research organizations repeating experiments with very low NPR mass additions to sulphidic wastes. In 2013, heterotrophs were identified and quantified as they grew on German lignite with NPR. These data conclusively showed that the development of heterotrophic biofilms is a consequence of adding waste NPR leading to a reduction of sulphide oxidation and improved effluent from sulphidic mining wastes. We document our gradual understanding of the effects of NPR on the reduction of sulphide oxidation, covering 23 years of research.

Jan 1, 2014

By T. G. Joseph, M. Bolster, M. Curley

"High tirerim loading on haul trucks operating on rough ground frequently manifests as mechanical separations and rim base cracking caused by cyclic fatigue. This paper provides an understanding of the impact of high loads on rim component life and tire footprint, bulge, and deformation behaviour; and develops a maintenance planning tool to predict strain implications of high g loading for a given rim location. Loading tests and analyses were conducted for a tirerim arrangement under increasing load and internal tire pressure. Graphical models were developed, allowing higher g load extrapolation predictions for specific rim components.KEYWORDS g load, Mining, Model, Prediction, Rim, Strain, Tire bulge, Tire footprint, Ultra-class vehicleRÉSUMÉ L’application d’un chargement élevé sur le système pneu/jante de camions de transport rou¬lant sur des terrains accidentés se manifeste fréquemment par des séparations mécaniques et une fissure à la base de la jante engendrée par une fatigue cyclique. Cet article nous permet de mieux comprendre l’incidence de l’application de charges élevées sur la durée de vie des composantes de la jante ainsi que sur l’empreinte, la hernie et le comportement de déformation des pneus. Il développe également un outil de planification de l’entretien visant à prévoir l’incidence des contraintes en cas d’application d’un chargement g élevé sur un endroit donné de la jante. Des essais et des analyses de la charge ont été effectués pour un agencement pneu/jante soumis à une charge et une pression interne du pneu croissantes. Des modèles graphiques ont été développés, ce qui a permis d’établir des prédictions sur la base d’une extrapolation du chargement g plus élevé appliqué à des composantes spécifiques de la jante.MOTS CLÉS charge g, contrainte, empreinte du pneu, exploitation minière, hernie du pneu, jante, modèle, prédiction, véhicule ultralourdINTRODUCTION The purpose of this paper is to report on a proposed and trialed tire performance test based on data obtained from controlled testing that is used to predict the impact of high g loading on hauler rims and tires with greater accuracy. For example, for many years oil sand mining operations have expressed qualitative beliefs that an impact load of the magnitude experienced by a rim and tire arrangement is not detrimental to a rim as a stiff component; however, mining equipment components are subjected to cyclic loading where failure can result from repeated load/unload activity, truncating the peak region of a stress–strain response and resulting in fatigue failure at a stress value that is less than the peak value. The outcome reported by oil sand haul truck maintenance groups indicates they have realized that most high g impacts—such as those experienced by hauler tires and rims operating on poor ground conditions—can result in failure due to cyclic loading, where higher loads require fewer cycles for failure. This high-level loading and the resulting strain transmitted to the rim is evident in the results of the laboratory testing presented in this paper."

Jan 1, 2019

Flotation of a mineral bearing particle is the result of successful completion of a chain of events, such as, producing particles with sufficient exposure of the valuable mineral on the surface, reagent adsorption, suspension of the particle in the pulp, collision of particle with air bubbles and subsequent attachment, ascending to the froth column and transport to the concentrate stream, among others. These sub-processes in turn are affected by the feed properties such as size and density, and process variables such as size of air bubbles, degree of turbulence in the cell, particle/particle interactions etc.. Thus, inefficiencies occurring in any one or more of the above processes will result in inefficient flotation performance. In spite of its dependency on a wide variety of sub-processes, flotation performance is commonly modelled based on first order kinetics using two or three parameter models. As the model parameters may be affected by several of the sub-processes mentioned above, interpretation of their variations and identifying the specific causes is extremely difficult. Of the many factors that influence the flotation performance, liberation information of the particles such as the grade distribution and surface exposure are considered vitally important. In this paper, it has been demonstrated a) how a predictive liberation model may be derived and used in quantifying the liberation information of the particles produced at various grind sizes and b) how the flotation process may be modelled by explicitly incorporating the liberation information, thereby improving the accuracy of the model. Comparisons of the observed data with the proposed model and those of published liberation/flotation models have also been made.

Jan 1, 2016

By Mohammed Rachek

Résumé : la mine d?Elhammam, opération du groupe minier Marocain Managem, est située au sud de la ville de Meknes à 63 km, elle exploite un gisement de fluorine depuis 1974. La minéralisation se présente sous forme de deux filons principaux orientés N45° avec un pendage variant de 65 à 90° NW, entre ces deux filons on note la présence d?une succession de filons satellites sécants. La méthode d?exploitation pratiquée depuis le démarrage de la mine est celle des chambres magasins, elle assure une cadence d?extraction annuelle de 250000 tonnes. Cette méthode favorisée par une très bonne compétence mécanique des épontes de la minéralisation a offert à l?exploitation une rentabilité très satisfaisante grâce à son faible coût mine. Les travaux de recherche géologique menés en parallèle à l?exploitation ont permis la découverte d?un nouveau secteur ?K-Est Gouaïda? (KEG) qui fait l?extension nord-est du gisement principal, la minéralisation de ce secteur se présente sous forme de deux filons très étendus latéralement (900 m d?extension) et présentant une puissance minéralisée irrégulière et très faible 1.2 m en moyenne, les épontes de la minéralisation sont constituées de schistes de qualité mécanique très faible. Vers la fin des années 1990, l?exploitation s?est orientée vers le développement minier du secteur KEG. Ce développement consiste à faire le choix adéquat de la méthode et de l?infrastructure minière pour l?exploitation de ce nouveau secteur, KEG. La méthode des chambres magasins, pratiquée dans le gisement principal avec un faible coût mine, n?est pas praticable dans le nouveau secteur à cause de la qualité de ses terrains, l?irrégularité de la morphologie de sa minéralisation et de la faible puissance des ses filons. Seule la méthode des tranches montantes remblayées (TMR) peut être applicable techniquement vu les spécifications suscitées de la nouvelle minéralisation, la TMR doit être appliquée sous sa variante mécanisée pour faire face au niveau exigé de la production. Après le pilotage de l?exploitation par TMR mécanisée dans le secteur KEG, il a été confirmé que cette méthode donne une grande satisfaction en matière de stabilité des terrains, sécurité, sélectivité, productivité et récupération du gisement, néanmoins elle reste pénalisée par un coût mine trop élevé pour garder le niveau de rentabilité recherché par l?exploitation d?un produit de faible valeur marchande telle que la fluorine. Dans l?objectif de rentabiliser l?exploitation du secteur KEG qui représente en réserves l?équivalent d?une durée de vie de 4 à 5 ans et d?assurer la pérennité de l?activité, l?exploitation en collaboration avec Reminex, la filiale d?ingénierie de Managem, a adapté une nouvelle variante de la TMR mécanisée dite TMR avec plan incliné sur remblai. Cette nouvelle variante de la TMR consiste à réduire au maximum les travaux dans le stérile en reconstituant un plan incliné sur le remblai à l?intérieur des filons pour faire évoluer en vertical l?exploitation des tranches en montant vers la tête d?un panneau de minerai. La variante des tranches montantes remblayées mécanisées avec plan incliné sur remblai a été imaginée et appliquer en 1978 dans la mine de fluorine de Burc située au Sud-Ouest de la France (Sicard et Mailloux, 1983). Imaginée pour une cadence annuelle de 30000 tonnes et une mécanisation très modérée cette variante a été adaptée par l?exploitation de la mine d?Elhammam en 2002 pour un haut degré de mécanisation et une cadence d?extraction annuelle de 250000 tonnes de minerai. Cette variante de la TMR est appliquée depuis le début de 2003 dans les chantiers du secteur KEG, elle présente les mêmes avantages techniques que la TMR mécanisée classique et elle a permis la réduction du volume des travaux d?infrastructure de 17.65 m à 6.25 m de travaux par 1000 tonnes de minerai. Ceci s?est traduit par une baisse du coût technique de la mine de 34% ce qui a donné un nouveau souffle à la mine pour assurer sa production et pour poursuivre la recherche géologique d?éventuelles zones à mettre en valeur.

Oct 1, 2004

By David A. Grieve, David E. Pearson

"A rank-map of Crowsnest coalfield, showing the distribution of the bituminous coal measures and the locations of major structures, has been produced from vitrinite reflectance measurements on over600coal samples. The timing of coalification in relation to these major structures has also been determined.In the west-central portion of the coalfield a complete stratigraphic succession of coal measures which rides on major thrust surf aces is all of high-volatile bituminous rank, but despite the structural discordance no break in rank is discernible across these structures. The thrust faults therefore predate much of the coalification.Three major valleys expose cross sections of the folded coal measures and in each an increase invitrinite reflectance is demonstrable as individual seams are traced from ridge crest to valley floor. Thus, in these sections, a significant amount of coalification post-dates folding. The proportion of this post-folding coalification is found to increase toward the south of the coalfield.A late gravity-fault, exposed along the east crop of the coalfield, places high-volatile coal-bearing successions in contact with low-volatile coal and demonstrably is a reactivated thrust fault. Coalification at this locality occurred between these two different ages of faulting.The variations in rank and the subtleties of the coalification pattern have, together with systematic changes in the maceral composition of coal seams, had a profound effect on coal quality in the coalfield. Coking coals with a variety of properties occur together with some coals that have no caking capacity."

Jan 1, 1985

By J. G. Patterson

"The depressive action of sodium cyanide on chalcocite has been investigated and found to be unstable. Flotation results show that with the addition of sodium cyanide to the system chalcocite is initially depressed but rapidly recovers with time, provided there is sufficient oxygen present.lt is proposed that the unstable depression is due to the reaction of cyanide with adsorbed xanthate and copper ions at the chalcocite surface to form soluble copper complexes. When all the free cyanide has so reacted, xanthate anions can then re-adsorb on the chalcocite surface and the flotation will recover. Results are presented to verify the the above mechanism."

Jan 1, 1968

By Richard Samson

"RésuméComme l'exploitation d'un gisement à grande profondeur représente un défi de taille et que la profondeur à laquelle se situe celui d'Ansil varie de 1200 m à 1460 m, nous avons dû mettre en place une infrastructure de surface d'envergure incluant un treuil de production et un chevalement d'une très grande capacité. De même, l'infrastructure sous terre a été proposée en tenant compte de ce fait important; d'ailleurs, l'excavation de deux puits circulaires dont l'un est en beton et acier et l'autre exclusivement en béton en témoigne. De plus, la plupart des cheminées principales qui furent excavées sous terre sont de forme circulaire.L 'exploitation du gisement s'effectue par une méthode chantier ouvert (abattage par longs trous), remblaye immédiatement âpres avec un mélange de roche stérile et ciment. Un taux de minage de 1750 tonnes par jour est requis pour assurer la production.L 'utilisation d'une technologie de pointe tels: les ventilateurs et les portes de ventilation sous terre contrôlées de la surface, un système de relèves macroséismiques, de chargeuses-navettes contrôles à distance, en passant par le dessin et la planification assistes par ordinateur nous permet d'optimiser l'exploitation du gisement Ansil.IntroductionEtant donne la grande profondeur a laquelle le gisement Ansil se situe, no us avons à mettre en place une infrastructure souterraine et de surface d'envergure pour nous permettre d'atteindre nos objectifs d'exploitation.Infrastructure de surfaceLa mine Ansil dispose d'une infrastructure de surface d'importance possédant une grande capacité (Fig. I). Les deux facteurs qui furent déterminant pour le dimensionnement des infrastructures furent le taux d'extraction de 1990 t/jour et la profondeur a laquelle I 'exploitation s'effectue, puis que cette dernière affecte le temps de cycle et la capacité de hissage.La première composante principale de I 'infrastructure de surface est un treuil de production a 2 tambours de 3.65 m de diamètre et de 2.0 m de largeur chacun. Ce treuil de marque Fullerton, Hodgart & Barclay construit en 1970, opère avec 2 moteurs de 930 kW a une vitesse de 700 m/min. et il a une capacité maximale de 32000 kg. Deux câbles d'acier de 45 mm de diarnètre et de 160 000 kg de résistance a la rupture servant au hissage des bennes d'une capacité de 12 tonnes. De plus, un moteur/générateur de 3000 kW (M.G. Set) raccorde au treuil de production sert a stabliser son alimentation électrique."

Jan 1, 1991

By Fritz F. Prugger

In August, 1970, during routine shaft grouting, a major water source was intersected. Water and quicksand under very high pressure entered the shaft at a rate of 65 m3 per minute. The mine and both shafts were flooded. The breach was sealed simultaneously from within the shaft and through a relief hole drilled from surface. The mine was dewatered, rehabilitated and the equipment was restored. Production resumed two years after the accident.

Jan 1, 1979