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By R. L. Bruening, N. E. Izatt, S. R. Izatt

The need for selective metal separations has increased as the mining industry encounters more complex ore bodies and demand for higher performance end products expands. The Molecular Recognition Technology (MRT) process uses highly selective SuperLig® resins to remove desired metals from a variety of solutions in the mining and metals processing and recovery industries. MRT separation processes efficiently produce high purity metal products. In this paper, applications of MRT to metal recovery at mg/L to multiple g/L concentration levels are presented and discussed. Specific examples in the precious metal, nickel, cobalt, zinc, copper, and rare earth industries are given.

Jan 1, 2014

"The rocks of Notre Dame Bay form part of the Central Paleozoic Mobile Belt (Williams, 1964) of the Newfoundland Appalachians. The Central Paleozoic Mobile Belt of the northern part of the island consists predominantly of Lower and Middle Ordovician rocks overlain by Silurian elastic and volcanic sequences and underlain in the marginal zones of the belt by polydeformed metamorphic rocks of the Gander Lake Group (Kennedy and McGonigal, 1972) in the northeast and the Fleur de Lys Supergroup (Neale and Nash, 1963; Kennedy, Phillips and Neale, 1972) in the northwest. The Ordovician rocks of the Central Mobile Belt have been subdivided into a number of local groups in different parts of the region. The Lush's Bight Group was first defined by MacLean (1947) . Recently Marten (1971) has revised the definition of this group, as shown in Table 1 and his revised definition is accepted in the present paper. Plate tectonic models that have been proposed for the development of the Newfoundland Appalachian System have indicated that the mafic volcanic rocks of western Notre Dame Bay represent oceanic crust (Bird and Dewey, 1970; Dewey and Bird, 1971; Church and Stevens, 1970) which marks the remnants of the proto-Atlantic Ocean first proposed by Wilson (1966) . Such models infer that the mafic volcanic rocks constitute the upper part of an ophiolite sequence. Analyses of the lavas show that they are tholeiitic and support this conclusion (Papezik and Fleming, 1967; Smitheringale, 1972) . A complete ophiolite sequence, consisting of peridotites overlain by gabbros, overlain by a sheeted diabase dyke complex which passes upward into pillow lavas, occurs at the base of the Snooks Arm Group (Upadhyay et al., 1971 ) . Sheeted diabase dykes are known to underlie the lowest mafic pillow lavas of the Lush's Bight Group at several localities in Notre Dame Bay (Strong, 1972, and pers. comm.) . However, several conflicting points about the geology of this region suggest that although a typical oceanic crustal sequence of Lower Ordovician age is present, older rocks occur within the ophiolite terrane in several places (Williams, Kennedy and Neale, 1972) ."

Jan 1, 1972

By B. Lafrance, C. J. Beaumont-Smith, L. R. Jones

"Abstract - The Burnt Timber gold deposit is located in the Paleoproterozoic Lynn Lake greenstone belt of the Trans-Hudson Orogen, Manitoba. The deposit occurs along the Johnson shear zone, and is hosted by enriched and depleted tholeiitic volcanic arc basalts cut by feldspar porphyry dikes. The Johnson shear zone is a regional, belt-parallel structure characterized by the intensification of the regional S2 foliation. At the Burnt Timber deposit, S2 is folded by centimeter- to meter-scale, Z-shaped, F3 chevron folds that have an axial planar S3 crenulation cleavage. Within the 20 to 30 m-wide core zone of the shear zone, S2 and F3 are transposed parallel to S3 and the volcanic rocks are strongly sheared parallel to S3. The presence of a steeply plunging stretching lineation, together with dextral shear sense indicators along both S2 and S3 on horizontal surfaces, suggest that the Johnson shear zone is a dextral transpression zone. Gold was introduced in pyritic, biotitic, and carbonatized mafic volcanic rocks along the core of the shear zone. Mylonitic mafic volcanic rocks contain localized high-grade zones (=10 g/t Au) that differ from wider carbonatized, low-grade zones (<3 g/t Au) by the presence of deformed gold-bearing quartz-pyrite veins. High-grade zones are also associated with swarms of quartz-pyrite veins that cut across sericitized and carbonatized feldspar porphyry dikes, which acted as brittle, competent bodies during shearing. Gold deposition in the high-grade zones was controlled by the channeling of hydrothermal fluid along the core of the shear zone during shearing of the volcanic rocks, and brittle fracturing of the porphyry dikes. Sommaire - Le gîte aurifère de Burnt Timber est situé dans la ceinture de roches vertes Paléoprotérozoïque de Lynn Lake dans l’orogène Trans-Hudsonien, au Manitoba. Ce gîte est situé le long de la zone de cisaillement de Johnson et est encaissé dans des basaltes tholéiitiques d’arc enrichis et appauvris recoupés par des dykes porphyriques. La zone de cisaillement de Johnson est une structure régionale parallèle à la ceinture de Lynn Lake caractérisée par une intensité accrue de la foliation régionale S2. Au gîte de Burnt Timber, S2 est affectée par un plissement F3 en chevrons en Z d’échelle centimétrique à métrique associé à un clivage de crénulation de plan axial S3. Dans la zone centrale de 20 à 30 m de largeur au sein de la zone de cisaillement, S2 et F3 sont transposés parallèlement à S3 et les roches volcaniques sont fortement cisaillées le long de S3. La présence conjointe d’une linéation d’étirement à forte plongée et d’indicateurs cinématiques dextres sur les surfaces horizontales S2 et S3 suggère que la zone de cisaillement de Johnson est une zone transpressive dextre. L’or a été mis en place dans des volcanites mafiques altérées en pyrite, en biotite, et en carbonate au coeur de la zone de cisaillement. Les roches volcaniques mylonitiques présentent des zones aurifères locales à haute teneur (=10 g/t Au) qui diffèrent des zones à basse teneur (<3 g/t Au) par la présence de veines de quartz et de pyrite aurifère. Des zones à haute teneur associées à des essaims de veinules de quartz et de pyrite sont aussi notées dans des dykes porphyriques à plagioclase altérés en séricite et en carbonates; ces dykes se sont comportés comme des corps compétents durant le cisaillement. La déposition de l’or dans le zones à haute teneur a été contrôlée par la circulation du fluide hydrothermal au coeur de la zone de cisaillement durant la déformation des roches volcaniques et la fracturation des dykes porphyriques."

Jan 1, 2006

By R. K. Netolitzky

The Weedy Lake, Tower Lake, and Wedge Lake gold deposits illustrate contrasting styles and different ages of mineralization within the same district. The discovery of these deposits was the result of systematic exploration of gold occurrences noted during research of assessment files. The Weedy Lake and Tower Lake depo its reflect a late-stage gold mineralizing event. The e deposits developed along the same major structural break, and also display simi lar mineralogy and alteration patterns. Mineralization is developed in all the lithologies present. The Wedge Lake property, while having occurrences similar to the Weedy and Tower deposits. has the more important Twin Zone which best fits a volcanogenic exhalative model. The Twin Zone has a complex structural history without a recognizable alteration halo. The setting may be proximal to a hydrothermal vent. Mineralization is hosted within a mixed ulphide/oxide/silicate facies iron formation breccia. and the gold is intimately associated with arsenopyrite. The origin and age of the brecciation is key to understanding the mineralizing event. Traditional prospecting procedures in conjunction with conventional B-horizon soil geochemistry were instrumental in the Twin Zone and Weedy lake disco,•eries. Tower Lake was a prospecting discovery partially defined by previous drill programs. This deposit was also identified by B-horizon oil sampling.

Jan 1, 1986

Increasing depths and mechanization of underground mines have led to the production of large amounts of gaseous and particulate contaminants. Over 100 000 lives have been lost due to methane gas and dust explosions in coal mine workings in both the United States and Canada since 1900. There is, therefore, the need to constantly assess and evaluate the performance of existing mine ventilation systems to maintain safe and acceptable mine environmental conditions. This paper advances research initiatives in the control of methane gas in underground mine environments. It uses the results of continuous monitoring of methane gas concentrations conducted in selected coal mines in North America to assess the effectiveness of existing auxiliary ventilation systems to control methane gas concentrations. The results show that the average quantities of fresh air required to dilute, disperse and remove methane gas concentrations within set levels of one minute varied from 5.43 m3/sec. to 27.97 m3/sec. in the development headings. The average dilution times in the headings studied were less than eight minutes. The calculated dilution efficiencies of the auxiliary ventilation systems in the headings varied from 12% to 139%. These efficiencies ranged from poor to excellent. This implies that the auxiliary ventilation systems were capable of controlling the methane gas concentrations below statutory levels but may not be able to cope with large and unusual methane gas concentrations in the headings. This study is significant in the control of methane gas and coal dust explosions in coal mines.

Sep 1, 2001

By D. R. Boyle

"The basal type uranium deposits in south central British Columbia occur within unconsolidated, late Miocene fluvial paleochannel sediments that overlie major fault zones within the Okanagan Highlands Intrusive Complex. Prior to the formation of mineralization, paleovalleys containing host sediments were flooded by Pliocene valley basalts of the Plateau Basalt Formation. Five uranium deposits have been outlined to date, of which the Blizzard (4020 tonnes U) and TYee (650 tonnes U) are the largest. The basement intrusive complex underlying the deposits varies in age from early Cretaceous to Eocene and is comprised of quartz monzonite, granodiorite, Coryell monzonite, porphyritic granite and pegmatite.The mineralized host sediments comprise a complex sequence of interfingering conglomerates, arkosic sandstones and mudstones. Organic material is abundant in many, but not all, mineralized beds. Uranium mineralization is present in the form of uranous (ningyoite) or uranyl (saleeite, autunite) phosphates coating clastic grains and filling voids. Because of very strong reducing conditions related to large concentrations of marcasite and organic material, ningyoite is the only uranium mineral in the Tyee deposit, whereas the Blizzard deposit contains a more complex assemblage of minerals (saleeite, autunite, ningyoite). The observed paragenetic sequence of mineral precipitation in the Blizzard deposit (autunite-saleeite-ningyoite) indicates that the uranyl minerals, saleeite and autunite, are primary. Small amounts of Zn, Ni, Co and Mo have been introduced into the Blizzard deposit whereas Mo is the only non ore-forming element enriched in the Tyee deposit. Mn is the only depleted element in both deposits."

Jan 1, 1986

By C. I. Godwin

"The relative-value (R-value), discrimination-factor (D-factor), and vector-ratio (V-ratio) method (RDVM) provides a geological knowledge-based statistical and geological-genetic interpretation scheme for geochemical data that enhances discovery in geochemical exploration. The practical advantage of RDVM is that it synthesizes geochemical features geologically related to ore-deposit discovery in three steps: reclassifying element concentrations using log-probability plots into R-values; calculating geologically defined D-factors from R-values; and determining V-ratios. D-factors are the sum of R-values, divided by the number of R-values summed. Based on the analyses selected, D-factors mimic rock or mineral deposit signatures. V-ratios refine interpretations of rock type and vector to orebody locations.RÉSUMÉ La méthode de la valeur relative (valeur R), du facteur de discrimination (facteur D) et du rapport de vecteurs (rapport V) (RDVM), fournit un schéma d’interprétation des données géochimiques basé sur les statistiques et les connaissances géologiques et la génétique géologique; ce schéma contribue aux découvertes en exploration géochimique. L’avantage pratique de la RDVM est qu’elle fait la synthèse des caractéristiques géochimiques reliées géologiquement à des découvertes de gisements de minerais en trois étapes : une reclassification des concentrations des éléments au moyen de courbes de probabilité logarithmique en valeurs R; un calcul des facteurs D définis géologiquement à partir des valeurs R et la détermination des rapports V. Les facteurs D sont la somme des valeurs R divisés par le nombre de valeurs R additionnées. Selon les analyses choisies, les facteurs D imitent les signatures de la roche ou des gisements minéraux. Les rapports V peaufinent les interprétations des types de roches et dirigent vers des emplacements de gisements."

Jan 1, 2016

By E. Asselin, G. K. Yue

"In the present study, electrochemical measurements, especially cathodic potentiodynamic polarization (CPC) and cyclic potentiodynamic polarization (CPP), have been employed to study the kinetics of ferric reduction on chalcopyrite in aqueous Fe(II)Fe( III)H2SO4 solution at 90 °C and 110 °C. Results from the calculation of speciation in the above solution reveal that, at both 90 °C and 110 °C, the real Fe3+/Fe2+ ratio is much lower than the nominal ratio, which leads to smaller VALUES (for the reversible potential of the ferric/ferrous couple. Exchange current densities of the ferric/ferrous couple were obtained and are on the order of 106 10 5 A/cm2 a t 9 0 °C and 1 07 10 6 A/cm2 at 110 °C, respectively. The Tafel slopes from the CPP method are higher than those from the CPC method at both 90 °C and 110 °C. The transfer coefficients were about 0.360.59 at 90 °C and 0.370.65 at 110 °C. Based on the exchange current densities obtained, the rate constant kc was calculated. It was found that kc at 90 °C was slightly larger than at 110 °C, especially for the results obtained by the CPC method. The average rate constants are 862.17 cm/s for CPC and 65.30 cm/s for CPP at 90 °C, and 477.69 cm/s for CPC and 63.53 cm/s for CPP at 110 °C for nominal Fe3+/Fe2+ ratios ranging from 1:1 to 1000:1. INTRODUCTIONChalcopyrite is one of the most abundant copper-bearing minerals, accounting for approximately 70% of the world’s known copper reserves (Wang, 2005). Most of the currently proposed leaching processes are based on sulfuric acid with ferric ions and/or dissolved oxygen as oxidants. Some of these processes have been piloted in attempts to implement these technologies on an industrial scale, such as Activox (U.S. 5,232,491, 1993), Nenatech (U.S. 5,993,635, 1999), Dynatec (U.S. 5,730,776, 1998), AAC/UBC (U.S. 6,503,293, 2003), Total Pressure Oxidation (U.S. 5,698,170, 1997), CESL (U.S. 5,874,055, 1999) and Galvanox (U.S. 7,846,233, 2010).To date, much effort has been devoted to understanding the kinetics and mechanisms of the oxidative processes (Biegler & Horne, 1985; Córdoba, Muñoz, Blázquez, González, & Ballester, 2008, 2009; Ghahremaninezhad, Asselin, & Dixon, 2010; Hirato, Majima, & Awakura, 1987; Hiroyoshi, Kuroiwa, Miki, Tsunekawa, & Hirajima, 2004; Warren, Wadsworth, & El-raghy, 1982) or the cathode reduction reactions of chalcopyrite itself (Arce & González, 2002; Biegler & Swift, 1976; Biegler, 1977; Nava, González, Leinen, & Ramos-Barrado, 2008), by chemical or electrochemical methods. However, as the most important cathodic processes in chalcopyrite leaching systems, the cathodic reductions of ferric ions or dissolved oxygen are worth measuring due to their effects on the overall leaching rate, as predicted by mixed potential theory."

Jan 1, 2012

By Ralph W. Edie

"IntroductionTHE GOLDFIELDS AREA in northern Saskatchewan has be-come important in recent years because of numerous discoveries of pitchblende. The area is underlain by rocks of Precambrian age and, because of metamorphism and hydrothermal alteration, the geology in the vicinity of the pitchblende deposits is exceedingly complex and presents a challenge to all geologists •working in the district. This paper is a contribution to the geological literature of the area and presents a description of rock types, supplemented with petrographic, chemical, and spectrochemical data.Field work in connection with this paper was carried out during the summers of 1948, 1949, and 1950 while the writer was employed as assistant geologist for the Crown Corporation, Eldorado Mining and Refining ( 1944), Limited, Gold-fields area. Laboratory work was undertaken at the Massachusetts Institute of Technology during the winter months of 1949-50 and 1950-51 and extended through the summer of 1951.With the exception of SiO2and FeO, all of the new analyses ( 1) presented were carried out by quantitative spectrographic techniques under the supervision of Dr. L. H. Ahrens at M.I.T. Many of the techniques have only recently been developed at that Institute and detailed laboratory procedures have not yet been published."

Jan 1, 1952

By M. Kumral, E. Dilhuydy, B. Ozdemir

"In-pit crushing and conveyor (IPCC) systems have become increasingly popular in the mining industry as an alternative to truck-and-shovel systems. Deciding whether to haul waste rock by truck or IPCC represents an important gap to be investigated in semi-mobile IPCC systems. A cost analysis is presented to evaluate the feasibility of crushing and conveying waste material in IPCC systems, along with sensitivity and risk assessments through Monte Carlo simulation. Although the capital expenditure is higher, results showed waste crushing will be feasible in deep pits and over long mine life and haul distances.RÉSUMÉ La popularité des systèmes de concassage et de transport dans la fosse minière (IPCC, de l’anglais In-pit crushing and conveyor) n’a cessé de croître dans l’industrie minière ; ils constituent en effet une option intéressante de remplacement des systèmes par camions et pelles mécaniques. Le choix entre le transport des stériles par camions ou par IPCC est encore difficile à faire et devra faire l’objet d’une étude approfondie au niveau des systèmes d’IPCC semi-mobiles. Une analyse des coûts est présentée pour évaluer la faisabilité du concassage et du transport des stériles par les systèmes d’IPCC, de même que des évaluations de la sensibilité et des risques par le biais de la simulation de Monte Carlo. Si les dépenses en immobilisations s’avèrent être plus élevées, les résultats ont cependant montré que le concassage des stériles sera envisageable dans des fosses profondes ainsi que sur une longue durée de vie et de longues distances de transport. INTRODUCTIONThe mining industry is currently facing many challenges such as low commodity prices, increasing environmental concerns and regulations, lower grades, deeper mines, and greater waste-rock quantities. As a result, the profitability of mining operations has decreased, with many mines stopping or suspending operations, and many new projects being postponed. Mining companies have therefore focused on improvements and innovations to increase the cost effectiveness of operations, for example, increasing production capacity to take advantage of the economies of scale (Crowson, 2003) and decreasing the unit operation cost. Changes in production capacity force mining companies to evaluate alternative material handling systems.During the past few decades and within material handling systems, significant improvements have been made to truck performance and capacity. Consequently, operating expenditures (OPEX) associated with fuel and maintenance have risen swiftly. In a mining operation, truck hauling systems now represent 40–50% of the capital cost and approximately 45% of the OPEX (Tutton & Streck, 2009). Additionally, material transportation costs are expected to increase due to longer haul distances arising from deeper and larger mines (Fleet et al., 2015). Finally, large fluctuations in fuel prices result in high risks associated with truck OPEX. According to the United States Energy Information Administration (2015), the cost of crude oil—the largest component of the retail price of diesel fuel—increased from US$24.31/barrel in 1986 to US$46.92/barrel in 2016, peaking at US$151.72/barrel in 2008 (Macrotrends, 2016)."

Jan 1, 2017

By Aaro E. Aho

Yukon, one of the most potentially accessible, relatively undeveloped, regions of Canada, has major mineral possibilities. The Klondike placer gold fields and the Mayo silver-lead ?district are the sole major producers but large base-metal re-serves have been discovered in re-cent years and important asbestos deposits are now being explored. Several major exploration companies are active in this region despite short seasons, permafrost overburden, remoteness, lack of transportation, and resultant high costs. Pro-posed new roads can be expected to accelerate development. At ?present the major future mineral possibilities are considered to be lead-zinc, copper, aslbestos, silver-lead, gold, and mineral fuels. These and other mineral possibilities are outlined for various geological subdivisions of Yukon. Major favourable metallogenic features of Yukon include complexity of rock types and structures, widening of the Cordillera with cross-trends, and variety and quantity of mineralization found even with limited prospecting. Comparisons with southern &apos;British Columbia and the U.S. Cordillera suggest that further exploration will result in discovery and development of more major ore deposits and reserves which will eventually revolutionize economy of mining in Yukon. Such mineral resources, with interior petroleum and natural gas possibilities, and ?huge coastal hydroelectric power potential, are the foundations of a much larger future mining industry in Yukon.

Jan 1, 1958

By Philippe Angers

This article analyzes the social acceptability process of a mining project located in an existing city. It will explore how the principles of sustainable development have been integrated in the project of the Canadian Malartic open pit mine held by the Osisko Mining Corporation, and the corporate social responsibility (CSR) initiatives proposed to strengthen the social acceptability of the project. This mine is located on the ancient south quarter of Malartic and has required the displacement of hundred of houses and five institutions. The location and the inherent social impacts generated by the relocation of the citizens of the south quarter makes this case particularly interesting to understand social dynamics in an era of environmental consciousness. These major constraints of the mine generate high expectations within the urban population with regard to the social and economic benefits it will receive from the project. In a context where society demands higher CSR from the corporation, Osisko is closely followed regarding their actions toward the sustainable development principles to see if they respect the environment and the desires of the community. From the beginning, the company had to be a model of sustainable development in various aspects reflected by the manifold interest of the population. To understand the endeavor made by the company to fulfill the demand of CSR, we will analyze how the company understood sustainable development principles and what CSR initiatives Osisko company put forward. We will explore the involvement of the company in various social aspects like employment, employee satisfaction, and the level of commitment to non-discrimination policy in employment, notably with the native populations. We will also take a closer look at the relationship built by the company with the community and the level of commitment with the various stakeholders of the community. In this way, we will be able to seize the level of involvement of the company in the fulfillment of the principles of sustainable development toward a higher CSR, and to specify the trajectory adopted to build social acceptance.

Aug 1, 2013

By M. R. Hegge

The Jabiluka One and Two uranium deposits occur in Lower Proterozoic metasediments of the Cahill Formation, which is part of the Pine Creek Geosyncline in the East Alligator River area, Nothern Territory. The Jabiluka One deposit coincides with a "window" through unconformably overlying Middle Proterozoic sandstone of the Kombolgie Formation; Jabiluka Two is completely covered by that sandstone. The observed part of the Cahill Formation exhibits four horizons which are favourable hosts for uranium mineralization. These have been folded into an east-southeast-striking, gently plunging, open asymmetric syncline-anticline structure. The host rocks are mainly chlorite and/or graphite schists and their brecciated equivalents which have undergone initial regional prograde metamorphism to the amphibolite facies, then retrograde metamorphism to the greenschist facies. Mineralization consists of pitchblende, mainly filling open spaces and to a lesser extent in disseminated form. Chlorite, pyrite and quartz are commonly associated with the uranium mineralization. A portion of the Jabiluka Two deposit contains economic concentrations of gold. Structural preparation with low-pressure conditions at these sites appears to be the most significant ore control. Genetic hypotheses favour initial deposition in Lower Proterozoic sediments, followed by remobilization during later orogenic events. The deposits bear a marked similarity to some pitchblende deposits in central Canada.

Jan 1, 1977

By Ian R. Morrison

"Abstract - The Izok Zn-Cu-Pb-Ag volcanogenic massive sulfide deposit is located 265 km south of Kugluktuk (Coppermine), Nunavut Territory, Canada, in the west-central Slave structural province. The Izok deposit is owned 100% by Inmet Mining Corporation and represents one of the largest undeveloped zinc-copper resources in North America. The Izok deposit is hosted within and near the top of a thick sequence of predominantly felsic pyroclastic rocks of late Archean age. The hanging-wall stratigraphy includes additional felsic volcaniclastic rocks, andesitic and basaltic flows, thin sulfide-rich iron formations, and turbiditic sedimentary rocks. The felsic volcanic rocks are intruded by intermediate dikes and sills, followed by gabbroic dikes and sills. Both intrusive suites are interpreted to be volcanic feeders to the overlying flows. All lithologies are subsequently cut by younger, irregular, granitic pegmatite and diabase dikes. The volcanic and sedimentary rocks are regionally metamorphosed to pyroxene hornfels grade. The massive sulfides occur within a large (kilometer-scale) Na-depleted sericitic alteration zone. The immediate footwall and hanging-wall rocks to the deposit are characterized by zones of muscovite- biotite-sillimanite, lesser chlorite-biotite-cordierite, and locally intense silicification and sodium metasomatism. All lithologies have been affected by younger Ca-metasomatism. As currently defined, the Izok deposit comprises a cluster of five complexly zoned composite lenses: the Northwest, North, Central West, Central East, and Inukshuk lenses. The first four lenses are amenable to open-pit mining, whereas the Inukshuk lens will require underground development. The total indicated mineral resource presently stands at 16.5 million tonnes with a grade of 2.2% Cu, 11.4% Zn, 1.1% Pb, and 60 g/t Ag. Inmet Mining Corporation is presently reviewing the economic feasibility of developing the property."

Jan 1, 2004

By Charles T. Harper

The uranium deposits discovered by Amok (Canada) Ltd. in the Cluff Lake area of north western Saskatchewan occur at or near the southern edge of the uplifted basement core of the Carswell circular structure. Two types of mineralization, distinguishable, by their geological and structural setting and mineral paragenesis, have been recognized. The N-Claude type is characterized by a relatively simple mineral assemblage, consisting of uraninite or pitchblende with coffinite, and is accompanied by variable amounts of graphite and organic matter, and Fe, Cu, Pb and Mo sulphides. Both N and Claude orebodies occur within quartzofeldspathic gneisses of the basement core. On the other hand, the D-type ore has a complex mineral assemblage consisting of: uraninite, pitchblende, thucholite and coffinite, along with native gold and selenium; gold tellurides, and selenides of Pb, Bi, Ni and Co; sulphides of Fe, Cu and Pb; and organic matter. The D orebody occurs within carbonaceous shales at the base of the Athabasca Formation as well as in fault zones in regolithic quartzo feldspathic gneisses above the inverted unconformity. An age of 1050 m.y., which is consistent with a period (circa 1200-1000 m.y.) of widespread hydrothermal activity and uranium mineralization or reworking within and adjacent to the Athabasca Basin, has been obtained from uranium mineralization from the D orebody. Later reworking (circa470 m.y.) of the mineralization occurred at the intersection of older mineralized shear zones with radial faults produced during meteorite impact.

Jan 1, 1978

By Y. Gordon

ABSTRACT A methodology based on a two-stage approach was developed for process technology selection. The first stage includes evaluation of available technologies, followed by shortlisting the best technologies based on mass and energy balance modelling, financial analysis, and risk analysis. The second stage involves detailed analysis using refined input data, mass and energy balance modelling, and capital and operating cost estimation, as well as a more detailed financial analysis. A case study covering the selection of ironmaking technologies for a company in the Russian Federation is presented to illustrate the critical elements of the methodology and the analysis process.

Jan 1, 2014

The properties required for a com-pound to form useful thermoelectric materials are described. Uranium compounds which might have these properties are reviewed. Several of these compounds have been prepared and fabricated into compacts. The apparatus used for hot pressing, and for the measurement of thermoelectric power, electrical conductivity and thermal conductivity, is described. Detailed attention has been given to the properties of the nitrides. Preliminary studies on a number of other uranium compounds are reported. The figures of merit of the best materials so far examined are one-tenth of those necessary for a useful thermo-electric material. THE efficiency of thermoelectric materials for power generation and cooling is determined by their figure of merit, Z = a2 a/K, where a, a and K are thermoelectric power, electrical conductivity and thermal conductivity, respectively. It is well known that the largest values of Z are achieved with semiconductors (1). High mobility of charge carriers is necessary for simultaneously high thermoelectric power and electrical conductivity.The properties required for a com-pound to form useful thermoelectric materials are described. Uranium compounds which might have these properties are reviewed. Several of these compounds have been prepared and fabricated into compacts. The apparatus used for hot pressing, and for the measurement of thermoelectric power, electrical conductivity and thermal conductivity, is described. Detailed attention has been given to the properties of the nitrides. Preliminary studies on a number of other uranium compounds are reported. The figures of merit of the best materials so far examined are one-tenth of those necessary for a useful thermo-electric material. THE efficiency of thermoelectric materials for power generation and cooling is determined by their figure of merit, Z = a2 a/K, where a, a and K are thermoelectric power, electrical conductivity and thermal conductivity, respectively. It is well known that the largest values of Z are achieved with semiconductors (1). High mobility of charge carriers is necessary for simultaneously high thermoelectric power and electrical conductivity.

Jan 1, 1963

By Michael K. Watkeys, Charlesworth. E. GUY, Jacobus E. Potgieter, Anhaeusser. Carl R., Roger L. Gibson, Alexander F. M. Kisters

Abstract - Intrusive features of cupriferous noritoids from the deeply eroded Proterozoic granite-gneiss terrane of the Okiep Copper District in South Africa illustrate the emplacement of basic magmas into a mid- to lower-crustal environment. The small, easterly trending intermediate to basic intrusions of the so-called Koperberg Suite display a wide variety of geometries, occurrence and emplacement modes, including dike-, sill- and plug-like bodies. Coeval granulite-facies metamorphism, partial melting and ductile deformation of country rock gneisses during intrusion of the basic magmas led to emplacement and dilation processes of the intrusions which differ significantly from those described for dikes and sills at shallow crustal levels. Regional tectonic stresses are largely negligible due to very low differential stress (?1 - ?3) during deformation and intrusion, which permits emplacement at high angles to the principal compressive stress and which follows favorably inclined structural anisotropies. Dilation of the basic intrusions is largely determined by compositional differences of host rocks and occurs by thermal erosion, i.e., assimilation of wall rock gneisses. Low length-to-width ratios of basic to ultrabasic dikes and predominantly diaper -like outlines of mesocratic bodies are indicative of low viscosity contrasts between the mafic magmas and high-grade metamorphic host-rock gneisses. Buoyancy-controlled ascent of the basic to intermediate intrusions is expressed by a broad compositional zoning of basic bodies with respect to the granite-gneiss stratigraphy. Various intrusion modes within the stratigraphic column of the granite-gneiss sequence reflect a lithological and structural stratification of the seemingly homogeneous granite-gneiss terrane.

Jan 1, 1994

By Donald Carlisle

"IntroductionTHE OPINION is held by many persons outside the mining industry, and by some within it, that mine •operators customarily find it advantageous to mine •only the richer parts of orebodies and to leave behind, perhaps permanently, leaner material which could be mined only at a lesser profit. This opinion and the inference which might be drawn from it that 'gutting' of mineral resources is a common feruture• of the mining industry are prejudicial to the intertsts of the industry and deserve careful scrutiny. Oddly enough, a theory of mine economics which gives much support for the opinion was advanced first by members of the mining profession itself, has been repeated •several times in mining literature, and to my knowledge has never been adequately refoted.According to the theory, selective mining of the rich ore first on a large scale will yield substantial gains and these gains do not merely reflect the desire of 'money minded investors' for a quick return but derive from the logical application of compound interest rates and the concept of ;present value. W. O. Hotchkiss and R. D. Parks (1) illustrate the reasoning with a hypothetical example in which an orebody of 4,000,000 tons may be mined either in its entirety in forty years at $1.00 per ton profit or selectively with the recovery of only the richest half in twenty years at $1.50 per ton profit. They show that, with Hoskold rates of 4 and 8 per cent, the present value of profits from mining only the richer 2,000,000 tons exceeds the present value of profits :from mining the whole orebody by about 20 per cent."

Jan 1, 1953

By J. Forster, C. A. Pickles, Mackowiak. K.

The future development of nickel laterite deposits is crucial with regards to satisfying impending nickel demands. The commercial implementation of new hydro/pyrometallurgical processes in recent years has led to significant improvements in the extraction of nickel from the laterite ores. One potential alternative pyrometallurgical processing route would be to selectively reduce the nickel and produce a concentrate with nickel contents similar to those attainable in the conventional flotation of sulphide ores. However, even bench scale studies have not yet been able to produce a high grade (>15% nickel) concentrate from a low grade laterite ore. The present research involved the microwave vacuum reduction roasting of a nickel laterite ore to yield a high grade concentrate, rich in nickel. Firstly, the effects of temperature and pressure on the nickel grade and recovery were investigated using a thermodynamic model. Secondly, briquettes containing a mixture of charcoal and a low grade silicate nickel laterite ore were reacted in a microwave vacuum system. The experimental variables studied were the input microwave energy, pressure and absorbed microwave power. Thirdly, the ferronickel in the reacted briquette was concentrated by magnetic separation and nickel grades of up to 21% could be achieved.

Jan 1, 2015