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By J. E. Hawley, Y. Rimsaite, T. V. Lord

"IntroductionIN THE COURSE of. a spectrographic investigation of the platinum metal .content of various minerals in sulphide ores, the use of • fire-assay beads dissolved in gold-amalgam ( 1) was found suitable for the quantitative determination of palladium and platinum. Later work on platinum and bismuth-rich beads showed however, that these could not always be readily mixed uniformly in the amalgam. Accordingly another technique was sought which would allow the simultaneous determination of gold, silver, palladium, platinum, rhodium, and bismuth, the last .a common contaminant in fire-assay beads. The method evolved, which consists of dissolving fire-assay •beads in .lead, resembles in several respects the method of Scobie (2) in which silver was used. It has equally good sensitivity arid reproducibility, and allows the determination of silver as well as the other metals mentioned. The 'mutua1 standard' method of calculation (3a) is used to determine actual quantities present. This method has been applied to sulphide and arsenide minerals and •ores• of nickeliferous and non-nickelferous deposits• of both pre-and post Cambrian age, and, following a suggestion by Dr. G. S. Hume and the late Dr. H. V. Ellsworth, Geological Survey of Canada, has also been used for a peculiarly rich platiniferous uranium oxide ore from the Nicholson property, Lake Athakaska, Sask. More recently, the method has been .tested for the determination also of iridium and ruthenium and results indicate it may be applied, as• well to osmium."

Jan 1, 1953

By Timothy W. Ellis

Wire Bonding is the dominant IC interconnection process presently used in the semiconductor assembly industry (1). The flexibility, adaptability and cost of wire bonding will continue to keep it as the key process for the interconnection of integrated circuits to substrates. However, wire bonding still has certain technological hurdles to overcome if it is to continue following the semiconductor roadmap (2). Particular issues which need to be addressed include low overall tensile strength, low elastic modulus, low shear per unit area and mechanical loop stability of Gold based micro-alloys. The ability to produce ?Deformation Process Metal-Metal Matrix Composites? (DMMCs) is based upon the deformation nature of immissible metallic systems. For reference, the Gold (Au)-Molybdenum (Mo) phase diagram is shown in Figure 1 (3). By inspection of the diagram, Au has a very low solubility for Mo, while Mo has essentially no solubility for Au. This is the metallurgical analog of oil and water. In the Au-Mo case, this is particularly troublesome when producing precursor ingots of the alloy to be formed into wire products. In Table 1, the melting points and densities are shown for Au and Mo. As shown, the melting point of Mo is significantly higher than Au, and is very close to the boiling point of Au (2856°C). However, Au?s density is higher than that of Mo. As such, conventional casting techniques are not suitable, since solid Mo would float off the surface of an Au melt thus depleting the matrix of its alloy addition. In this work, two-phase composite wires were produced by deformation processing to develop an interconnection wire with elevated tensile strength, modulus and shear to those commonly available in the market (4). This technology has been used previously in the production of high strength electrical conductors particularly for high field pulsed magnets (5).

Oct 1, 2003

By Stanley G. Hutton, Robert Brubaker

"It has long been recognized that mining workers subjected to high levels of hand-transmitted vibration may suffer from vibration-related complaints. Prolonged exposure to whole-body vibration may also result in adverse effects. In this study, the effects of vibration on mining workers are examined. Previous work documenting the occurrence of vibration-related disease is reviewed. From this work, it is apparent that operators of hand-held pneumatic rock drills are exposed to a significant risk of developing vibration disease. Vibration levels recorded on the rock drills now in use are presented and shown to exceed levels recommended by a proposed ISO standard.IntroductionThe possible harmful effects of exposure to excessive vibration levels have long been recognized, particularly among operators of hand-held tools. Numerous cases have been reported of a vasospastic disorder commonly known as vibration white finger disease (VWFD), which was a term coined by the Industrial Injuries Advisory Council in Scotland in 1970(1 ), Those suffering with the disorder have frequent vasospastic attacks in which the fingers, hand and, in advanced cases, the lower arm turn white and numb, usually after a cold stimulus. Advanced stages of VWFD have been reported in which the skin becomes ulcerated and gangrenousm. The incidence of the disease has been particularly serious in the forest industry due to the extensive use of chain saws. However, in recent years, the introduction of antivibration saws has resulted in a significant reduction in the occurrence of the disease.In a recent report for the Canadian Department of Supply and Services - Energy, Mines and Resources, Hutton & Brubaker considered the effects of vibration on workers in the mining industry. In this report, the physiological and medical effects of vibration were considered, relevant vibration standards were discussed, previous vibration measurements were documented and field measurements carried out. In the present paper, the results recorded in this study will be summarized, together with results that have been previously published relating to vibration levels existing in the mining industry."

Jan 1, 1982

By R. H. Pemberton

"THE Mattagami district of Quebec has, during the past few years, experienced intense exploration by virtually every mining company operating in Canada. As a result of this activity, a number of well-mineralized zinc-copper bearing bodies have been found, some of which will almost certainly go into production. Much of the area has undergone what is now termed ""Saturation Prospecting"" or intense and detailed geological and geophysical surveying, followed by the drilling of nearly all possible bets. Considering only the airborne geophysical surveying, some blocks of ground have been flown by virtually every geophysical instrument which has to date been installed in an aircraft. A list of these different geophysical instruments would include: l. Fluxgate-type total field magnetometers 2. Vertical field magnetometer ,3. Nuclear-precession magnetometers 4. Single-frequency out-of-phase electromagnetometers 5. Dual-frequency out-of-phase electromagnetometers 6. Horizontal component measuring electromagnetometers 7. In-phase and out-of-phase electromagnetometers8. Dip-angle measuring electromagnetometers."

Jan 1, 1961

By Stephen G. Downs

PCF?, or Penetrating Cone Fracture, is a propellant-based technique for rock excavation, which has significant potential for the mechanization of narrow-vein mining. The technique is currently being developed for use in the narrow-vein flat-dipping gold and platinum deposits in South Africa in conjunction with major mining companies. The technique is also applicable to steeply dipping vein deposits, such as those found in North America, Australia and elsewhere. The implementation of PCF? in South Africa to date is reviewed and plans for the introduction of PCF? excavation in other areas are highlighted.

Oct 1, 2001

By J. -C. Sztuke, M. Cao

ABSTRACT The correlations between froth recovery of coal and air recovery were investigated using a hybrid mechanical flotation column. The particle slurry was fed onto the surface of air-water two phase froths to carry out the tests. Froth recovery was taken as the recovery of particles into the froth product, whereas air recovery was determined by the froth height method. The relationships between froth recovery and air recovery were nearly linear, with greater slopes for more hydrophobic particles. Inside the froth phase, the particles were stratified, with hydrophobic particles concentrated in the upper region and hydrophilic particles in the lower region.

Jan 1, 2013

"Horizontal grinding mills have been used in the mining industry for more than a century, and due to their operational and maintenance simplicity they remain a widely used technology for various stages of comminution. The relative ‘efficiency’ of horizontal grinding mills compared to other comminution equipment is often debated, and efforts to improve the energy efficiency of these mills is an on-going area of attention for process engineers.The discharge arrangement design affects the material transport characteristics within a horizontal grinding mill. Material transport plays a significant role on efficiency of horizontal grinding mills. The magnitude of benefits that can be achieved with efficient material transport in AG/SAG mills has been demonstrated in a Greenfield milling operation at Mirabela Mineração’s SantaRita Nickel operation in Brazil. This grinding circuit was commissioned in October 2009, which was designed as a typical SABC circuit to grind 4.6 mtpa (575tph) to produce a P80 of 125um with 10-12% ball charge in SAG mill. The nameplate design capacity has been achieved in few days in ABC circuit without grinding media in SAG mill, and has been operating in ABC mode. The through has gradually increased to an average of 800 tph and recently 7% ball charge has been introduced to increase the throughput to +900tph.This paper investigates improved material transport using Outotec’s TPL™ (Turbo Pulp Lifter) technology and the opportunities this technology presents when designing horizontal grinding mills. Operational data, with particular reference to energy and throughput optimization, is presented."

Jan 1, 2013

During the past decade, the miner-al industries have been faced with an increasing shortage of engineers. The point has now been reached where the shortage may be termed critical. This shortage may be attributed directly to declining enrollment in the mineral science programs offered by the universities on this continent. Although the reasons for declining enrollment are undoubtedly many, two major hypotheses may be postulated. The first is that high-school graduates are either unaware of the mineral industries and the opportunities in them or that they are aware of them but have somehow obtained a false image of their true nature. The second is that they are aware of the true nature of these industries and the opportunities they offer but find them exceedingly unattractive. The problem of dwindling enrollments has, in recent years, been subjected to a concerted attack by the industries and professions concerned. However, their efforts to date have been based essentially on the first hypothesis. Sufficient results are now available to suggest that either the methods of attack are inappropriate

Jan 1, 1965

By D. K. Uko

In the stretch-bend or bending-under-tension test, a strip is rigidly clamped and restrained at each end and bent by central transverse loading using a radiused punch: The strip deflection at failure has been used as a measure of formability for high-strength low-alloy (HSLA) steels by other investigators. In this work, a detailed study is made of strains developing during stretch bending of an 80,000-lbf/ in 2 (552 MPa) yield stress steel using different punch radii. It is shown that toward the end of the process, the bending strains at both the inner and outer surfaces are tensile and suddenly increase at a rapid and approximately equal rate. The strain ratio in the failure region departs significantly from plane strain , even using a large width-to-thickness ratio of about 10. The effective fracture strains appear to be independent of bend ratio (punch radius/thickness) and significantly below the fracture s train in simple tension. Metallographic and tensile data were obtained for the subject material and, for one bend ratio, the effects on stretch-bend parameters of annealing both on this material and a. carbon steel were compared.

Jan 1, 1977

By G. Lipsett, S. Dessureault

Information technology (IT) initiatives in the past have tended to be sold on their ability to maximize resource output and return on capital by allowing assets to be used more effectively and efficiently. Many IT projects fail, not delivering return on their investment. This is known in the IT industry as the “productivity paradox,” where increasing investments in IT do not result in comparable increases in productivity. Experiences and studies of most business sectors reveal that this paradox is rooted in the false assumption that more IT spending automatically results in financial benefit, whereas the benefits are in how effectively IT is used. Most business sectors have accepted that re-engineering of processes is required to gain the full benefits promised of IT. A mining operation has organizational processes similar to most business sectors, but unique operational processes. The lessons of changing business practice in more common business processes, such as inventory control and customer-supplier relationships, can be adequately transposed into a mine setting. The unique operational processes in mines, in turn, require unique redesign efforts. Several enabling information technology opportunities have recently become available, such as more integrated mine production management systems and tactical manager training simulators. This paper reviews some of the latest IT products and outlines the processes and kinds of change that will be required in order to benefit from these new investment options.

Jan 1, 2009

By D. A. Rhys, M. Sieb, M. A. Prefontaine, C. L. Swanson, S. R. Frostad, H. Q. Smit

"Gold-silver mineralization at Red Mountain (1992 resource of 2.5 million tonnes grading 12.8 g/t Au and 38.1 g/t Ag) occurs within several discrete zones within a folded sequence of Middle to Late Triassic Triassic sedimentary rocks, Early Jurassic volcaniclastic and pyroclastic rocks, and Early Jurassic intrusions. Three phases of Early Jurassic sills and stocks collectively comprise the Golds/ide intrusions: (1) irregular bodies of medium-grained hornblende monzodiorite (Hillside porphyry); (2) hornblende-biotite + quartz porphyritic monzodiorite to quartz monzodiorite (Golds/ide porphyry; U-Pb zircon ages of 197.1 + 1.9 Ma); and (3) biotite porphyritic hornblende monzodiorite sills (Biotite porphyry). Contact breccias and igneous breccia dikes are common features of the Golds/ide intrusions. Chemical similarities and equivalent ages of volcanic rocks and intrusions, and the presence of intrusive clasts in volcanic rocks suggest that the intrusions are feeders to overlying volcanic units.Hydrothermal alteration affects all pre-Tertiary rocks on Red Mountain, including all phases of the Golds/ide intrusions. Several shallow-dipping alteration zones are developed sequentially above a propylitic quartz stockwork/molybdenum zone. These include: (1) sericite-quartz-pyrite alteration (pyrite-dominant alteration); (2) chlorite-K-feldspar-sericite-titanite alteration with disseminated and vein pyrrhotite (pyrrhotite-dominant alteration); and (3) brown to black tourmaline veins and K-feldspar-pyrite-titanite-actinolite alteration. Anomalous gold(> 0.3 g/t) mineralization is developed at the transition from the pyrite to the pyrrhotite dominant alteration over a > 1 km2 area. Within this anomalous zone, high-grade (3 g/t to 20 g/t Au) gold-silver mineralization occurs in 5 m to 29 m thick, semi-tabular pyrite + pyrrhotite stockworks with intense sericitic alteration and surrounding disseminated sphalerite + pyrrhotite.Stratigraphic, spatial and geochronologic relations and alteration zoning indicate that mineralization formed in a subvolcanic environment at the top of the Golds/ide intrusions and at the base of the Early Jurassic volcanic pile. The Golds/ide porphyry is interpreted to be the mineralizing intrusion. The alteration zoning, molybdenum-copper mineralized quartz stockworks, extensive Ksilicate and tourmaline alteration, and the relationship with a hypabyssal porphyritic intrusion show similarities to many porphyry systems."

Jan 1, 1995

By D. C. Peck, H. D. M. Cameron, N. M. Halden, L. S. Jobin-Bevans

Abstract-The late Archean Pipestone Lake anorthosite complex (PLAC) is a 0.9 x 17 km sill-like layered intrusion that is part of a suite of coeval megacrystic anorthosite bodies in the Cross Lake region, northwestern Superior Province. Exploration for Ti-V-Fe oxide mineralization and concurrent geological investigations have contributed to a greater understanding of the lithostratigraphy of the PLAC and its oxide mineralization. Mapping and drill core studies have established a laterally continuous igneous stratigraphy comprising six leucogabbro/anorthosite zones and three melagabbro/gabbro zones. Field evidence, including disrupted blocks of layered units, scour contacts, and size-graded and modally-graded layering, suggests younging towards both the northern and the central parts of the complex. A decrease in the anorthite content of the feldspars from An75 in the south to An30 in the north suggests that the magmas become more evolved to the north. Macrorhythmic layering and gross morphological features suggest that the PLAC crystallized from four major influxes of geochemically similar basaltic magmas. The paucity of magmatic erosional features in the PLAC indicates that layering developed in a relatively static magma chamber, so that in-situ crystallization processes are required to account for the observed petrologic diversity. Drilling has confirmed that a significant Ti- V-Fe resource is contained in two of the four discrete mineralized subzones in the PLAC. Textural evidence and the stratiform nature of the oxide-enriched subzones are consistent with a magmatic origin for the oxide mineralization.

Jan 1, 1997

By Stratton-Crawley R., G. E. Agar

"A study has been done of the scale-up of laboratory bench-scale flotation to continuous plant circuit performance. It was found that the impellor speed and the air flow rate influenced the results and in this case extreme values of these operating variables were required in order to reproduce the plant rougher results in the laboratory. Despite the experimental uncertainty introduced by these extreme values, it was demonstrated that the plant performance could be predicted and experimentally reproduced with bench-scale tests.IntroductionThe mineral processing industry relies heavily on batch flotation testwork to design flowsheets, evaluate reagent s and compare various types of ore. The batch tests are generally regarded as being directly comparable within themselves, but quite often they relate poorly or not at all to continuous circuits. Obviously this dilemma generates considerable uncertainty with wide-ranging ramifications. One of the manifestations of this unfortunate situation is the commonly expressed opinion that ""it may work that way in the laboratory, but it will never work that way in the plant"".In a previous publication, a method was described whereby the results of batch bench-scale tests could be used to simulate a locked cycle flotation test series. The work to be described here is a continuation of that investigation with an extension to the simulation of an actual plant circuit. It would have been preferable to progress from laboratory batch data to a continuous pilot plant and then finally to a full-scale plant operation. However, because that possibility did not present itself, an attempt will be made to show that the performance of an existing plant circuit can be successfully simulated from batch data. The success of the procedure can be judged by the agreement among the plant results, a locked cycle test and the predicted results based on batch tests."

Jan 1, 1982

By K. M. Tompson, R. L. Armstrong, C. I. Godwin

"Tungsten skarn deposits on the Clea property in the Selwyn Mountains, Y. T., are related genetically to a quartz monzonite stock, about 500 metres in diameter at the surface. Lower Paleozoic sedimentary rocks are metamorphosed for a distance of 3 km from the stock. Tungsten-bearing skarn mineralization within the altered sedimentary rocks is of two types: sulphide-rich pods and calc-silicate beds. The most significant scheelite concentration is in calc-silicate beds near or adjacent to the quartz monzonite stock. Discordant K-Ar and Rb-Sr isotopic dates indicate that the stock is probably of early Late Cretaceous age, 94 Ma or slightly older, and that it cooled slowly. High initial 87Srl86Sr ratios and disequilibrium relationships between K-jeldspar phenocrysts and groundmass minerals in the porphyritic phase of the granitic rock , and between different granitic rock specimens, indicate contamination of crystallizing magma by old sialic continental crust which extends westward under the Selwyn Basin.This study is significant to regional tungsten exploration. Granitic rocks associated with tungsten deposits, in this part of the Canadian Cordillera at least, appear to have specific isotope characteristics that indicate they were generated at a specific time and in a particular way.IntroductionThe Clea tungsten skarn property (Fig. I) is owned by Canex Placer Limited, and lies in the Selwyn Mountains (Bostock, 1948) near the eastern margin of the Selwyn Basin (Wheeler and Gabrielse, 1972), Yukon Territory. The property covers a 20-square-mile area centered near latitude 62°47 ' north and longitude 129°52' west, and is accessible by helicopter. An airstrip and the terminus of a summer-use gravel road at MacMillan Pass, Yukon, are about 20 miles to the northnorthwest.This paper deals mainly with the geochronemetry of granitic rocks from a stock associated with tungsten mineralization on the Clea property. We show that these rocks have specific characteristics that not only define the genesis of this stock, but also have significance for regional tungsten exploration around plutons in the Canadian Cordillera."

Jan 1, 1980

By S. H. Ash

Introduction Probably the newest thing in mining safety is the apparent dissatisfaction on the part of the mineral industry, as represented by both management and labour, and the general public of many nations in which mining is conducted, with the safety record of the mining industry. This is reflected by published comments in the technical press;' in labour periodicals, in popular Journals and periodicals, and in the daily press (5, 11). Despite what may be said to the contrary, mining in the United States is becoming safer, and this trend has been evident for several years (see Figures 1 to 4). Because the author's experience has been mostly in the United States this paper will discuss briefly some recent observations in the United States that have a bearing on mining safety. Because coal mining is of primary interest to the Mining Society of Nova Scotia, the paper treats mostly of coal-mining safety; however, many hazards in mining .are common to all mines, regardless of the minerals mined.

Jan 1, 1950

By S. Y. Tshipeng, A. T. Kaniki

"RÉSUMÉ La lixiviation acide d’un minerai oxydé cupro-cobaltifère en milieu non réducteur et en milieu réducteur en utilisant le Fe2+ et le métabisulfite de sodium (SMBS) a été étudiée et les résultats ont été comparés. Les tests de lixiviation ont été effectués à température ambiante, dans une pulpe à 30 % solide, avec une vitesse d’agitation de 600 tr/min, un potentiel redox de 350 mV pour les tests en milieu réducteur, et un pH de 1,8. Les tests de lixiviation avec usage du SMBS comme réducteur ont donné la meilleure cinétique de lixiviation du cuivre. Pour le cobalt, c’est l’usage du Fe2+ qui a donné la meilleure cinétique de lixiviation. L’augmentation de la dose du fer dans la solution au-delà de 5 g/L a influencé négativement les rendements de lixiviation du cuivre et du cobalt. ABSTRACT Acid leaching of a copper-cobaltiferous oxide ore in a non-reducing environment and in a reducing environment using Fe2+ and sodium metabisulfite (SMBS) was studied and the results compa¬red. The leaching tests were performed at room temperature, in a 30% solids pulp, with a shaking speed of 600 rpm, a redox potential of 350 mV for the tests performed in the reducing environment, and a pH of 1.8. The leaching tests using the SMBS as a reducing agent produced the best copper leaching kinetics. As for cobalt, the best leaching kinetics was achieved using Fe2+. An increase in the amount of iron in the solution above 5 g/L negatively influenced copper and cobalt leaching yields. INTRODUCTION La République Démocratique du Congo (RDC) est un pays reconnu dans le monde pour son sous-sol qui regorge d’énormes quantités de cuivre et de cobalt (USGS, 2014; Palisade Research, 2016). La technique qui semble être la plus recommandée pour extraire à la fois le cuivre et le cobalt des minerais oxydés cupro-cobaltifères est la lixivia-tion acide en milieu réducteur. Cette technique est appliquée par la majorité des sociétés minières qui exploitent ces minerais dans l’ex-province du Katanga en RDC, à savoir: Tenke Fungurume Mining, Mutanda Mining, Kamoto Cop¬per Company, Sicomines, Gécamines, Boss Mining, Chemaf, Ruashi Mining et Somika. L’usage d’un agent réducteur est indispensable pour l’obtention d’un bon rendement de lixiviation du cobalt. En effet, plusieurs chercheurs s’accordent sur le fait que le cobalt trivalent de l’hétérogénite (CoO·2Co2O3·6H2O) est insoluble à l’action de l’acide seul; il ne devient soluble qu’après réduction en cobalt bivalent (Mwema, Mpoyo, & Kafumbila, 2002; Mulaba-Bafubiandi, Ndalamo, & Mamba, 2007; Ferron, 2008; Seo, Choi, Kim, & Tran, 2013; Stuurnam, Ndlovu, & Sibanda, 2014)."

Jan 1, 2018

By R. Biss

"Niobium or columbium, as usually called in North America is becoming a more and more important metal in the industrial world because of its attractive properties.Eventhough discovered in the early nineteenth century, it was not until the 1930's that its use became more widespread. The discovery of large commercial deposits in the late 1950's and the demand of industry for steel with high strength and toughness further promoted its use. To assure its adequate supply new or-e processinr technologies had to be developed. So, beside the traditional gravity concentration, the flotation process was employed for the partial upgrading of pyrochlore concentrate at S8ve (Norway) plant in 1953. The flotation process was equally used at St-Lawrence Columbium plant in the province of Quebec, Canada. The new plants at Araxa and Catalao in Brazil and at St-Honore, Canada, which supply almost of all niobium used today in the non-Communist world, also adopted the flotation process. The processes using long chain aliphatic rnonoarnines, diamines or sulfonates as collectors proved to be difficult especially on weathered types of ores or on those having a substantial content of silicate gangue minerals. They almost completely failed in case of alkaline intrusive rocks as syenites, nepheline syenite, ijolites and pyroxenites, composed almost entirely of silicate minerals. A lot of effort was devoted all around the world on research of new, more efficient flotation processes. So in 1982, Les Services T.M.G. Inc. (Niobec), sole producer of pyrochlore concentrate in North America, developed the direct pyrochlore flotation process from carbonatites. In 1983, at about the same time, the Quebec Department of Natural Resources Laboratories and Les Services T.M.G. Inc. announced a successful recovery of niobium Minera1s from a low grade nenheline syenite ore."

Jan 1, 1984

By Thorndycraftm R. B.

"PURPOSEThe purpose of this presentation to the Canadian Mineral Processors is to review gold heap leaching systems currently in use and discuss their applicability to Canadian ores. The author's experience with the development and operation of heap leaching spans the past four years at. Pinson, and visits to many ether heap leaches in the western United States.INTRODUCTIONBy way of introduction to the heap leaching system, I will describe in slight detail the method used at Pinson Mining in northern Nevada. This will be followed by a discussion of optional methods in use at other operations visited.The Pinson orebody is a finely disseminated, well-oxidized hydrothermal deposit. Gold particles are finer than 20- microns. The orezone hostrocks are metamorphosed and silici¬fied limestone and shale. Sulfides and carbonaceous materials are negligible.The Pinson open-pit mine has operated since June 1980. It produces 1500 tpd of C.I.P. mill feed averaging .10 oz gold per ton, and 1500 tpd of heap leach material averaging .025 oz gold per ton. Cutoff grades are 0.04 for mill feed, and 0.01 for heap leaching. Stripping ratio is 9 tons of waste and leach grade to 1 ton of mill feed.The project is located in northern Nevada at 4900 feet above sea level.,Winters are fairly severe, with freezing conditions affecting operations from early December through April. Although officially designated as ""high-mountain desert"" country, snow and/or freezing rain occur almost every week of the winter.To date, all Pinson production-scale heap leaching has treated run-90,000 tons of ore are stacked on 300 foot square clay leach pads. Cyanide leach solution is applied through ""wobbler"" sprinklers at .0025 gpm/sq ft for 60 to 90 days. The pregnant solution flows from the heap by gravity to plastic-lined ditches, into a collection sump and then through buried piping to the 2.2 million gallon pregnant solution pond."

Jan 1, 1984

By G. Lee, E. T. C. Spooner

"Molybdenum mineralization at Boss Mountain is hosted by the Triassic Takomkane quartz monzodiorite batholith and is associated with a Cretaceous monzogranite stock. Ore has been mined from a sheeted vein system that describes a partial annulus centred upon the apical region of the stock and from subvertical breccia pipes that emanate from the stock. Molybdenite precipitation is coincident with CO2 effervescence from a dilute (1.9 mole o/o NaC/ equivalent) hydrothermal fluid over a temperature range of 250°C to 370°C at a pressure of approximately 350 bars, interpreted to be greater than or equal to the lithostatic load and equivalent to a depth of 1.3 km or less.IntroductionThe chemical and thermal constraints on molybdenum transport and deposition to form molybdenum ore deposits are not well understood. To address this problem, the Boss Mountain mine in central British Columbia, operated by Noranda Mines Ltd., was chosen as a well-described (Soregaroli and Nelson, 1976), relatively small and simple example of a Cordilleran Mo~ deposit. It is situated on the northeast slope of Takornkane Mountain, 10 km west of the community of Hendrix Lake (N.T.S. 93A/2W; latitude 52°06'N, longtitude 120°56'W). Access is from 100 Mile House by nearly 90 km of road, the first 50 km of which are paved."

Jan 1, 1995

By K. Schimann, H. D. Knipping, J. P. Fouques

"RESUMELe gisement d 'uranium de Cigar Lake, dans la région de l'Athabasca au nord du Saskatchewan, fut découvert en mai 1981 par Cogema Canada Ltée, opérant pour Ie compte de la ""Waterbury Lake Joint Venture"".Le corps minéralisé. qui est dépourvu de toute expression directe en surface, est situé a la discordance entre les met sédiments du wottaston Group (Protérozoïque inférieur ou Aphébien) et les grès de l 'Athabasca (Protérozoïque moyen ou Hélikien), à une profondeur de 410 a450 m.Fin 1984, Ie gisement était reconnu par 105 sondages minéralisés repartis sur une longueur de 1800 m, pour une largeur comprise entre 25 et 105 m. 11 se présente sous forme d’une lentille aplatie de 5 a30 m de puissance, et montre une remarquable continuité d'ensemble. Une ride ou bombement topographique de la discordance est associée au gisement surtoute sa longueur.A l'échelle régionale, le corps minéralisé à est associe à un corridor structural d’orientation est-ouest, a l'intérieur duquel des facies particuliers aténdance blast mylonitique sont développes dans les formations métapolitiques agraphite du socle métamorphique. Il est entouré par un halo d'altération très important, caractériser Ie développement de minéraux argileux alumino-magnesiens (illite-chlorite).La minéralisation est située, pour la plus grande part, dans les grès d'Athabasca, et se compose essentiellement d'uraninite et de sulfo-arseniures de nickel et de cobalt,De nombreux levés géochimiques et géophysiques ont été effectues dans la région de Cigar Lake. Aucune anomalie ne peut être associée directement au corps minéralise, mais la combinaison des données en provenance de plusieurs sources s’est révélée fort utile au niveau de l’interprétation géologique régionale et de la définition des cibles de sondages a l'intérieur des zones reconnues favorables.Le gisement de Cigar Lake présente de nombreuses analogies avec plusieurs des gites classiques de la région de l'Athabasca; il est caractérise en particulier par l'intensité des phénomènes d’altération et la présence de minéralisations extrêmementriches.En 1984, les réserves géologiques globales estimées par géostatistique sur I ‘amas minéralise principal s 'élevaient a 110 000 tonnes d'uranium, aune teneur moyenne de 12.2%, avec une précision de 25% à l'intervalle de confiance de 95%.ABSTRACTThe Cigar Lake uranium deposit, in the Athabasca area of North Saskatchewan, was discovered in May 1981 by Cogema Canada LId., as operator of the Waterbury Lake Joint Venture. The deposit, which is devoid of direct surface expression, is located at the unconformity between the Lower Proterozoic (Aphebian) Wollaston Group meta-sediments and the Middle Proterozoic (Helikian) Athabasca sands tone, at a depth of 410 m to 450 m below surf ace.AI the end of 1984, the deposit had been defined by 105 mineralized holes over a length of 1800 m and a width of between 25 m and 105 m. It has the shape of a flat-lying lens 5 m to 30 m thick and shows a remarkable longitudinal and latera continuity from the information obtained to date. A well-defined bulge of the unconformity underlies the mineralized zone over its entire length.The deposit appears to be controlled by an east-west-trending structure within which a particular rock facies (""augen gneiss"") has developed in the graphitic metapelites of the Wollaston Group. It is surrounded by a strong alteration halo affecting both sandstone and basement, characterized by extensive development of Mg-A I rich clay minerals (illite-chlorite).The mineralization is hosted principally by the Athabasca sandstone, and consists mainly of uraninite and sulfo-arsenides of nickel and cobalt.Numerous geochemical and geophysical surveys have been carried out in the Cigar Lake area, and no specific geochemical or geophysical anomaly can be directly associated with the mineralized body, although there may be locally a good coincidence. However, a combination of several methods proved extre"

Jan 1, 1986