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By W. H. Patterson

The history and experience of early companies in the Islands is illustrated by the typical transactions of Trans-Western from 1959 to date. Trans-Western had entered into farmout agreements with companies strong enough to carry out at least the required minimum exploratory work and then such development as might be warranted. The farmee companies were required to make deposits to guarantee work performance during the first period of validity, i.e. the first 3 years of the 12-year life of the permits, and at the rate of 5 cents per acre. At that time, a good deal of geology was available, as a result of extensive exploration that had been carried on by the Geological Survey of Canada and other geological enterprises, with field parties travelling over and camping on all of those Islands. Trans-Western's farmees then selected, from Trans-Western's priority on 13.5 million acres, what they believed were the lands most prospective of producing large oil and gas discoveries, and, having the right to trim off acreage which they considered less prospective, thereby reducing the acreage of Trans-Western and its farmees to in excess of 5.5 million acres. The farmees then commenced a 3-year program carrying out geological exploration to the required minimum of 5 cents per acre, and with some permanent and many mobile camps.

Jan 1, 1969

By R. I. Kraydenko, A. N. Dyachenko

"The possibility of SiO2 5N production by staged purification of ammonium hexafluosilicate (NH4)2SiF6 is discussed. High-purity silicon dioxide can be obtained with fluoridation of quartz concentrate by solid NH4F at 100 °C, with further sublimation of the product at 320 °C, its dissolution, ammonia hydrolysis, filtration and drying of SiO2•nH2O. This is accompanied by regeneration of the processing reagent - NH4F.INTRODUCTIONProduction of high-purity silica-5N (SiO2 content over 99.999%) is an important and urgent task of the modern chemical industry. This material is used in the manufacture of optical glass, optical fibers for internet cables, silicon for solar power and electronics.Quartz concentrate is raw material for the production of silicon dioxide. The existing technologies of synthetic silicon dioxide were introduced in the mid-twentieth century. These methods are energy-consuming, multi-step and do not meet stringent environmental requirements. In fact, as some conventional technologies became obsolete; it became necessary to develop new methods for the production of synthetic silica. We believe that the fluoride technology of processing of quartz materials by ammonium fluoride is the most promising direction.In industry, silicon dioxide marked ""Silica White"" is obtained by liquid-phase method. The method consists of the precipitation of amorphous silica from sodium silicate solutions with acids. The resulting product is filtered, washed and dried. Depending on the deposition conditions and nature of the coagulant the ""Silica White"" is acidic, neutral or alkaline. The dry product is subjected to grinding. The degree of dispersion and porosity of the particles of Silica White depends on the nature of decomposition agent (a substance that decomposes the silicate) and coagulant, conditions of sedimentation, filtration and drying. During the drying process the silica particles are sintered into aggregates of a few millimeters."

Jan 1, 2012

By X. Shi

Magnesium, the lightest structural metal, has not yet been considered as a serious contestant for automotive use due to its weaknesses in corrosion. Electroless nickel-boron alloys are well known for their corrosion resistance and hardness. An electroless nickel-boron layer was successfully deposited first on the chemical conversion pre-treated AZ31 alloy and also on the Ni-P coating which was deposited on the conversion coating. The electroless bath contained nickel sulphate and dimethylamine borane (DMAB) as main salts and the samples were activated by a 5 g/L AgNO3 solution before the electroless plating process. The presence of the conversion coating between the nickel coating and the AZ31 substrate acted as a barrier and prevented corrosion of the alloy. The morphology of the nickel-boron layer was studied using SEM. The crystal structure and the composition were examined by EDS and the hardness was measured. The corrosion behaviour of the nickel-boron layer deposited on the conversion coating and on the Ni-P coating was studied using potentiodynamic polarization in a 0.5M NaC1 solution. A saturated standard calomel electrode was used as a reference electrode. The results show that the nickel-boron coatings had a significantly better corrosion resistance than the AZ31.

Jan 1, 2006

By Richard Stewart

There are highly competitive world markets in most of the minerals being mined today. The high standard of living we enjoy in North America results in ever increasing productivity through mechanization and automation. Conventional underground and open-pit mining practices throughout the world are constantly changing to reflect the engineering advances of our technology. New records in tunneling, shaft sinking and excavating are being established. Larger and faster equipment is in production. Mining operations are being studied in detail to improve materials, methods and machines. Standards and controls are being established to measure the performance of people and equipment. These steps all tend to improve our present performance. In addition to these short-range improvements, however, there are the basic research and applied research studies which are aimed at developing entirely new approaches to our mining problems. Basic research in rock mechanics is coupled with applied research in rock penetration, fragmentation and stabilization.

Jan 1, 1963

By Alireza Golabchi

The AEC (Architecture, Engineering, Construction) industry is an information intensive industry and all related processes employed during different phases of a project, including planning, designing, building, manufacturing, occupying, and maintenance, involve vast amounts of data that is used for a wide variety of purposes. Building Information Modeling (BIM) is a powerful shared knowledge resource which stores this data to support decision making about a facility through all these different phases in its life cycle. Nowadays, BIM is mostly used in the design and construction phases while it can also be highly beneficial beyond those stages. For example, in the Operation and Maintenance (O&M) phase, BIM could be used for automated facilities management or robotic inspection to provide semantic knowledge for navigation. For any implementation not related to the original intent of the BIM (design), organizations need to be able to represent their project data in a common interpretable form, which provides the possibility of an accurate exchange of data among different software products and platforms, known as interoperability. This study has investigated the current state of interoperability between software products used as Building Information Modeling tools. The main focus has been on a popularly used format for BIM models, Industry Foundation Classes (IFC), since it has been specifically developed to enable standardized data exchange. The research methodology involved a comprehensive literature review and the gathering of all fragmented prior research related to the field in order to develop a consistent understanding of the current state of knowledge. This was accompanied with a detailed case study that evaluated and compared two dominant pieces of BIM software, Revit and Bentley, and examined their interoperability strengths and weaknesses while using the IFC format.

Aug 1, 2013

By K. Szczesny

This paper considers the integration of uncertain real-time logistics data for reactive construction scheduling. In order to manage a construction project efficiently, an accurate schedule representing the current project progress is inevitable. The quality and up-to-dateness of such a schedule depends on the availability of real-time data. Typically, real-time logistics data contain information about the availability of material, equipment and personnel as well as delivery dates and site conditions. The accuracy and inherent uncertainty depends on the location where the real-time data was acquired. Currently, the integration of such data into a construction schedule is a very time-consuming, manual and, thus, errorprone process. Therefore, this paper proposes a methodology that enables an automatic integration of such uncertain data into construction schedules. By integrating uncertainties into the existing schedule their impacts on the construction work can be evaluated. For this, discrete event simulation is applied. In order to model uncertain input parameters for simulation models this methodology applies the fuzzy sets theory. In combination with alpha-cut sampling technique, discrete model input parameters are obtained. By applying reactive scheduling with several discrete event simulation experiments, the results can be used to modify construction schedules according to agreed timeframes and costs. In order to demonstrate and validate the presented approach an example is conducted.

Aug 1, 2013

By P. Leo

Al-Mg-Si alloys are widely used as medium-strength structural materials; extrusion is the most common processing route. In the present hot deformation investigation of a 6060 alloy, the microstructure of the alloy has been analyzed in the as-cast state, after homogenization heat treatment and after hot deformation by tensile tests in the range 400-490°C and 10-4 to 10-2s-1 on both as cast and homogenized alloys. After deformation the microstructure of the as-cast alloy exhibited cavitation. The flow curves at the lowest test temperature T show a gradual softening after a stress peak, being more evident for the alloy deformed in the homogenized state in association with a high yield stress; at higher T a plateau is attained which is lower as T rises and strain rates decrease. For each fixed T, the ductility decreases as strain rate increases for the homogenized alloy whereas, for the as cast alloy, it rises with strain rate. Constitutive analysis gives Q = 240kJ1mol for the homogenized alloy in agreement with published values; this indicates a more rapid strength decline with rising T than Al, suitable for good hot workability along with the lack of cavitation.

Jan 1, 2011

By W. A. Padgham, J. A. Brophy

About 85 % of the 350 tonnes of gold produced by 25 mines in the onhwe t Territories (NWT) since 1935 has come from the Yellowknife-area mines, Con and Giant , which exploit shear zones in Archean mafic volcanic of the Slave Structural Province. Four percent of the total production has been from Archean iron formation-hosted depo its, mainly from Lupin Mine, which today produces more gold than Con and Giant combined and has been primarily responsible for the increase of WT gold output from 5 to 12 tonne per year since 1981. The remaining gold ha been won from the following deposit typesall but the last being in Archean rock : sedimentary-volcanic contact depo its uch a Discovery and Salmita (10 %); turbidite-hosted quartz-vein depo its uch a Camlaren and Ptarmigan (1%); Proterozoic deposits such as Shear Lake and Fox (1#) . All but I% of WT gold has come from the Archean Slave Structural Pro ince, which is also the premiere exploration area for gold deposit types that have yet to be productive in the NWT. These types include stratabound gold in mafic and in felsic volcanic rocks (eg. , at Indin Lake and Courageous Lake, respectively) as well as gold in plutonic rocks (eg. Anialik Gnei Complex). Deposits similar to those in the Slave have al o been found in the Archean Ennadai Belt of the Churchill Structural Province. In the Cordillera. there is potential for placer gold and for gold associated with Cretaceou intrusions.

Jan 1, 1986

By M. C. Harris

"Excess Gibbs energy is a thermodynamic parameter which quantifies the difference between the value of the Gibbs energy for a real mixture and that for an ideal mixture. More specifically the partial molar excess Gibbs energy of a species (i) in a mixture is indicated by the change in the overall excess Gibbs energy of the solution as the number of moles of species (i) changes while keeping temperature, pressure and the number of moles of all other species in the solution constant. Generally it is obtained from the activity coefficient which in turn can be obtained for a species in a mixture using a variety of models. The most widely used method is to use UNIFAC. Flotation is probably the most important process in the concentration of minerals and requires the use of reagents such as collectors and frothers. There is abundant experimental data which illustrates that collectors of different alkyl chain lengths will change the contact angle and that frothers of different structures and molecular weights will result in changes in key flotation properties such as froth behavior, surface tension and critical coalescence concentration. In this paper it is shown that there is a strong linear relationship between measured parameters such as froth volume/height, surface tension, critical coalescence concentration and contact angle and the partial molar excess Gibbs energy of the molecules used. Proposals are made to explain these correlations.INTRODUCTIONAs is well known froth flotation is arguably the most widely used process in the separation of minerals. In broad terms the process relies on the use of reagents known as collectors to adsorb onto a mineral surface and thus render the mineral particle hydrophobic. Alkyl thiolates are very commonly used for this purpose. The hydrophobicity is induced as a result of the alkyl group’s molecular structural properties which results in it forming a non-ideal mixture with the process water. Surfactants (or frothers) are typically alcohols and are known to lower the surface tension of the system and also inhibit bubble coalescence and reduce bubble size. Since alcohols are polar they will also form a non-ideal mixture with water. The hydrophobic mineral attaches to the bubble and rises to the froth phase where the valuable mineral is recovered as a concentrate. Frothers have often been characterized using the so-called HLB (hydrophobic-lipophilic balance) number but recently it was shown that the use of activity coefficients (?) or excess Gibbs energy (G ex ), which is calculated using equation (1) is a much more appropriate way to describe the behavior of these reagents in non-ideal mixtures with water (Corin and O’Connor, 2014)."

Jan 1, 2016

By D. J. MacKinnon, Kazi E. Haque

Ammonia present in a variety of mine/mill waste waters was almost completely oxidized to nitrogen by chloride mediated electro-oxidation. A closed circuit operation of preconcentration of ammonia on a suitable adsorbent (e.g. zeolite or a resin) followed by brine stripping of ammonia and electrolysis of the strip liquor seems to have sound technical, economic and environmental merits. The removal of ammonia, cyanide, cyanate or thiocyanate from a mine/mill waste water (e.g. gold mill), either individually or collectively, is also feasible by chloride mediated electro-oxidation technique. Further R&D investigations are necessary for the development of a closed circuit operation for the removal of ammonia, cyanide and thiocyanate; and also to obtain technical data for process cost estimates

Jan 1, 1996

By J. J. Quinn

Several mineral flotation plants utilize process water with high soluble salt content. The processing of semi-soluble minerals, the use of recycle streams, sea or well water give rise to this situation. It is unclear as to the overall effect on flotation response though there does seem to be evidence of bubble size reduction, increased froth stability and reduced reagent dosage. The present work aims to quantify the effects of salts present in process water on gas dispersion (bubble size and gas holdup) and froth properties. The salts examined were NaCI, CaCl2, Na2SO4, Na2S2O3 and Al2(SO4)3. Tests were conducted to determine the effects of salt type and concentration on gas holdup and bubble size distribution. The salts containing multivalent ions had a greater impact than the monovalent ions, in keeping with the literature. A relationship between gas holdup and ionic strength was established. The concentration of frother (methyl isobutyl carbinol, MIBC) giving equivalent gas holdup was determined. The effect of salt and frother combinations was also explored.Proposed mechanisms for coalescence inhibition in salt solutions are briefly reviewed in light of the current findings.

Jan 1, 2006

By W. R. Smith

Introduction No commercial deposits of silica sand are known to occur in British Columbia, so all requirements for foundry and other uses must be imported. During the war, nearly 5,000 tons per year were used, all originating in Illinois and delivered to local consumers for about $12.00 per ton. Present requirements are somewhat less, but the cost is still of the same order. The relatively high cost of silica sand in British Columbia is not only a serious item for present consumers, but might be a deterrent to the establishment of a glass industry, should this be contemplated at any time. The present investigation was undertaken in an attempt to provide a cheaper source of silica sand within the Province. In 1936, a large number of beach and bank sand deposits in the lower coastal region of British Columbia were examined by the British Columbia Department of Mines, and samples were analyzed chemically and mineralogically. The deposits over the whole area proved remarkably uniform in mineral composition, consisting essentially of quartz, feldspar, ferromagnesian minerals, rock fragments, and various accessory minerals, and differing only in the relative proportions of the various constituents. In no case did the quartz content of any sand exceed about 40 percent and the average was of the order of 20 to 30 percent.

Jan 1, 1947

By Andrew Kerr

Overview of Presentation ? Introduction ? An historical context: From 1866 to the 21st century. ? Geological framework for iron ore in the region known as the ?Labrador Trough?. ? Producing iron-ore deposits of the Labrador City ? Wabush area, and near-future production from the Schefferville area. ? Exploration projects representing potential future production?.or expansion of the district. ? Some concluding remarks???

May 1, 2011

By T. H. Janes

"IntroductionSULPHUR is a constituent of many industrial products. It is part •of almost anything we eat, wear, or use. In fact, sulphur is so important that there has been an increasing tendency in recent years to measure industrial growth in terms of sulphur consumption.The uncertainty of obtaining adequate supplies •of elemental sulphur from the Frasch-mined domes. of Texas and Louisiana in the United States led all countries in 1950 to seek alternative sources of supply of this necessary element.Canadian industry has been supplied, for many years, with most of its sulphur requirements by United States Frasch-mined sulphur. World demand for this sulphur has necessitated the imposition of controls on its distribution, as production has not kept pace with demand. Until the third quarter of 1950, Canadian manufacturers of pulp and paper, heavy chemicals, explosives, and textiles •experienced little difficulty in obtaining their needs of elemental sulphur from the United States. However, at that time, low producers' stocks and declining reserves threatened to reduce shipments from producers, with the prospect of a continuing shortage for some time. These conditions, together with higher prices, stimulated the search for alternative sources of supply in Canada."

Jan 1, 1952

By A. B. Baldwin

"Uranium and thorium mineralization occurs at several localities in eastern Quebec along the north shore of the Gulf of St. Lawrence. The main occurrences are near Sept-Iles, Baie Johan Beetz, Romaine and St-Augustin river. Mineralization occurs mainly as disseminated uraninite, uranothorite, uranothorianite, monazite and minor zircon and allanite. Yellow to orange oxidation products are observed along fracture planes of the uranium-bearing deposits to a depth of a few feet. Magnetite, biotite and smoky quartz have a distinct tendency to accompany the radioactive minerals. The host rocks include white to pink pegmatite, pink granite and also, in the case of the Romaine and St-Augustin River occurrences, cream to grey plagioclase-rich, well foliated paragneiss and migmatite. Radioactivity near secondary structures, such as fractures and joint planes, indicates some reconstitution of radioactive minerals.The North Shore of Quebec is the northeast extension of the Grenville sub-province. It is also a uranium-thorium metallogenic province."

Jan 1, 1970

By L G. White

During 1958, prospecting parties working for the Mackenzie Syndicate in the Flat River area of the Mackenzie mountains, Northwest Territories, identified tungsten mineralization and located the property now being developed by the Canada Tungsten Mining Corporation Ltd. Scheelite mineralization, associated with pyrrhotite and minor chalcopyrite, occurs in lime silicate skarn replacement zones within a limestone-chert-argillite series intruded by granitic dykes originating from the ? main batholithic mass underlying the sedimentary beds. The results of surface outcrop sampling and 15,000 feet of grid-pattern diamond drilling have been combined to outline an orebody estimated to contain 1.32 million tons, grading 2.51 per cent WO after applying a 10 per cent dilution factor for mining purposes. T HE property of Canada Tungsten Mining Corporation Ltd. is located in the upper Flat River area of the Mackenzie mountains, Northwest Territories. Skarn-type replacement deposits containing scheelite mineralization are .situated between elevations of 4,500 and 5,500 feet above sea level along the east flank of the mountain range forming the boundary between the Yukon Territory and the Northwest Territories. The nearest supply center for the area is Watson Lake, Yukon Territory, located at Milepost 635 on the Alaska Highway.

Jan 1, 1963

By Ann Lamontagne

Le parc à résidus de l?ancienne mine Dunraine contient des résidus générateurs de drainage minier acide. Le concept proposé pour la restauration du site est d?utiliser le fort potentiel alcalin des boues rouges, résidus d?aluminerie, afin de neutraliser les résidus miniers. En appliquant une certaine quantité de boues rouges à la surface du parc, on provoquera une neutralisation de l?acidité. De plus, les alcalis contenus dans les boues rouges vont provoquer la précipitation de minéraux stables (sulfates tel la jarosite). La précipitation de ces minéraux provoquera la formation d?une couche indurée qui rendra difficile la circulation de l?oxygène et de l?eau. Bien que ce concept ait été vérifié en laboratoire, ce sont là des hypothèses qui restent à vérifier dans des conditions réelles d?exposition. Les principales questions soulevées par l?utilisation des boues rouges, mis à part le contexte géochimique, est le contexte technico-économique. En effet, le transport de quantité importante d?un matériel argileux humide présente un défi économique important. Outre le défi économique, la manipulation et l?épandage de ce produit sur des parcs à résidus constituent également un défi important. Cet article présente les conclusions d?une étude technique sur le transport, la manutention et l?épandage de boues rouges sur un parc à résidus situés en Abitibi : le site de Dunraine.

Nov 1, 2002

By M. Staite

This paper analyzed the feasibility of converting a 5kW natural gas SOFC power generator system designed to operate on natural gas to be fuelled by methanol. The analysis included laboratory methanol fuel processing experimentation, methanol reformate SOFC cell testing, and SOFC system mass and energy balance modelling. Methanol fuel processing experimentation indicated that theoretical reformate compositions can be achieved for high temperature (600-900°C) methanol steam reforming. A 6% open circuit voltage decrease and a 10% peak power current density decrease between cell operation on humidified hydrogen and methanol reformate was observed. SOFC system mass and energy balance modelling indicated that a natural gas SOFC system can be converted to operate on methanol fuel with minimal (1%) efficiency impacts, however the systems' thermal integration can be impacted.

Jan 1, 2005

By V. L. Mitsopoulos

This paper provides a summary of tailings disposal techniques and the improvements that have been made through the introduction of thickened tailings disposal. The general properties and characteristics of thickened tailings are described, as is a design process for selecting appropriate technologies for thickening, pumping, transporting and storing tailings. The factors affecting the selection of an appropriate disposal site and operational considerations for the effective utilisation of tailings storage areas are also documented.

Jan 1, 2006

By J. R. Kish, J. Dabrowski

"The susceptibility to intergranular corrosion modes is a major technical issue preventing widespread utilization of higher strength welded AA7xxx extruded beam profiles, in the peak-aged T6 condition, in automotive bumper assemblies. A study was undertaken to evaluate the relative exfoliation corrosion resistance (ASTM G85-A2) as a function of joint design parameters, namely the base alloy composition, heat-treated condition and beam orientation after exposure to a cyclic acidified salt spray test. This paper documents the major findings extracted from this study.INTRODUCTIONBumper systems play a predominant role in the passive safety of an automobile, since they are one of the main structures for absorbing the collision energy in the event of an automobile crash. Heattreatable AA6xxx-series (Al-Mg-Si) and AA7xxx-series (Al-Zn-Mg) Al alloys, with relatively high strength, toughness, energy absorption, weldability and formability, make it possible to design costcompetitive bumper systems to crush in a controlled fashion. In this context, Cu-lean AA7xxx extrusions, such as AA7003 and AA7108, which exhibit higher strength than AA6xxx extrusion, such as AA6082, represent an attractive light weight material from which to fabricate bumper assemblies (Clausen et al., 2000; Pedersen et al., 2008; Chen et al., 2009).Arc welding is a key joining process for AA7xxx alloys within the transportation industry. A major technological issue preventing widespread utilization of arc-welded AA7xxx joints is the susceptibility to severe localized corrosion (Kent, 1970, Reboul et al., 1985; Holroyd et al., 1987). It generally occurs as exfoliation corrosion within a heat affected zone (HAZ) a few millimeters from the weld bead, or a type of stress corrosion cracking (weld-toe cracking), which initiates at the weld toe and propagates into the interfacial region between the weld bead and the HAZ (so called “white zone”). In addition to the micro-galvanic cell activity induced by the intermetallic compound constituent and strengthening particles present, there is strong evidence that macro-galvanic cell activity between the weld bead and base AA7xxx alloy may be playing a controlling role. Electrochemical profiles taken across fusion welded joints, in cross-section, during exposure to saline solutions suggest that a significant potential difference exists across the AA7xxx arc-welded joint (Shumaker et al., 1967; Grauer and Wiedmer, 1980; Tuck, 1985, Onoro and Ranninger, 1993). These studies consistently show that the HAZ and base alloy are more electronegative with respect to the weld bead (arc-welded with AA5xxx filler wire). Despite this initial important work, the majority of the recent corrosion research effort on welded AA7xxx alloys has focused on the performance of friction stir welds (Lumsden et al., 1999; Wadeson et al., 2006; Hatamleh et al., 2009)."

Jan 1, 2012