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By C. Gaubert, G. Bourassa

"The construction or rebuild process in the anode baking furnaces has been modeled with the software Rockwell Arena, in order to minimize the process cost and risk. The case study was focused on the sectional rebuild (""on the fly"") that needs a high coordination of the material inventory, the on-site personnel and the construction/production schedule. Multiple entities and resources were allocated for the different part of the process (in-furnace process, prefabrication, materials transportation, etc.). Logic flow charts and VBA macros were used to simulate the space utilization (including cranes utilization) and interaction with production. MS-Excel output files can show user-friendly results."

Jan 1, 2006

By Ji Wang

Reflective in-seam wave detection has the advantages of a far detection range and wide applicability. It has been successfully used in detection of many abnormal geological structures in work-faces, such as faults and collapse columns. However, a reflective in-seam wave is a dispersion wave. It has weak energy and is always covered by the direct in-seam wave. In the past, underground seismic explorations were not able to image the opposite roadway using reflective in-seam waves. To solve this problem, we propose a new method of reflective in-seam wave imaging based on adaptive dispersion filtering. This method processes the reflective in-seam wave using a filter with the parameter of transmission distance. The degree of similarity of the filtered and the explosion signal is used to estimate the transmission distance and image the reflective objects. We test and verify this method using real underground seismic data. This research is helpful for the detection of coal mine goafs and abandoned roadways in work-faces or in front of tunneling ends.

Aug 1, 2013

By K. G. Chipman

The Geological Survey is the oldest map making department in the Canadian Government service, and when organized in 1842, one of the first principles to be recognized was the absolute necessity of having good maps. The primary purpose of the Survey has always been geology; but because a graphic representation by means of maps makes the written report .more readily intelligible; because the correlation of known geological facts is often difficult or nearly impossible unless they can be represented on a map; and, because the public demand information shown in this way, the Geological Survey must continue to supply maps; and the supplying of these maps must be considered as an essential part of the work of the Survey. It is a commonly recognized principle of pedagogics that an appeal to the eye is quicker than one to the ear; that children (and others) learn more quickly when a thing is presented to them through the eye rather than through the ear. The application of this principle to the work of the Geological Survey is that, to a large number of people, the message of a map is more quickly grasped, is more readily intelligible, and is in many ways of more interest and value than is the same information in a report. I do not mean that the maps are of more importance than the reports.

Jan 1, 1924

By Samuel Nunoo

Gibraltar Mine is an open pit copper-molybdenum mine in central British Columbia. The stability and potential failure modes of pit walls in the Granite Pit are controlled by the orientations of joints and faults. The structural geology also has an impact on as-mined bench geometries. Geotechnical mapping and surveying were conducted using stereo photographs and photogrammetry software. Detailed digital terrain models were constructed to determine the pit wall geometry and the locations and orientations of larger structural features. The pit wall geometry is compared to conventional survey results and the mapped structures are compared to results from a nearby geotechnical borehole.

Aug 1, 2013

By D. L. Johnston

"Function and ApplicationsWater-only cyclones, (WOC) are a dynamic mineral separator which cause minerals to separate in a water medium by virtue of difference in specific gravity. Figure 1 shows diagramatic plan and sectional views of a water-only cyclone.A slurry of mineral matter and water is fed through the inlet opening under gravitational or pump pressure. The combined effect of centrifugal action and conical shape is to concentrate the heaviest fraction of mineral on the periphery and bottom of the cyclone. This layer of higher specific gravity particles increases in thickness and density between the cyclone inlet and apex. The action in the bed of higher gravity particles formed in the flattened portion of the cone surrounding the tip of the vortex finder deter;nines the specific gravity of separation or cut-point. Mineral particles of lower specific gravity flow with the bulk of the water, out the vortex finder. Mineral particles of higher specific gravity flow with little water out the apex. A more technically e:mct description of the functioning of the water-only cyclone can be found in previous publications noted in the references.The water-only cyclone was invented and refined by J. Vis man, formerly of the Canadian Mines Branch staff, between 1958 and 1965. The first industrial application noted in the literature was when it was introduced as a cleaner for fine coal in 1962. Since 1970 the water-only cyclone has become a common separation apparatus in many Canadian and foreign coal processing plants. The only other mineral industry application known to the author is in separation of gold bearing heavy minerals from sand<'>. The potential does exist for other applications and this area deserves to be investigated more thoroughly than it has been."

Jan 1, 1989

By A. Perucho, J. P. Harrison, A. Bedi, L. Alejano, L. Lamas, A. Sofianos, A. M. Ferrero, R. Migliazza, R. Olsson, J-F. Mathier

"In 2010, the Eurocode for Geotechnical Design, EN-1997-1:2004 (CEN, 2004), informally known as Eurocode 7 or EC7, became the Reference Design Code (RDC) for geotechnical design – including rock engineering design – within the European Union (EU). EC7 is one standard within the comprehensive Structural Eurocode suite, which as a whole has been also adopted by a number of other countries beyond the EU. EC7 is thus becoming a key design standard for geotechnical engineering worldwide.As part of the Structural Eurocode suite, EC7 requires designs to adhere to the principles of Limit State Design. However, it is not clear that current rock engineering design practice can satisfy this requirement. In addition, evidence is accumulating that EC7 is currently difficult to apply to, and may even be inappropriate for, rock engineering design. These issues may be due to the fact that the development of EC7 to date took place without any formal input from the international rock mechanics and rock engineering community.In early 2011 under the auspices of CEN (Comité Européen de Normalisation / European Committee for Standardisation), EC7 entered a formal period of maintenance which was aimed at improving the applicability and ease-of-use of the Code. This maintenance cycle will conclude in 2020 with the publication of a revised version of EC7.This paper describes a number of critical aspects for rock engineering in the context of EC7, inparticular the following:– the history of the Structural Eurocodes and the concepts they embody;– the nature of Limit State Design and the challenges and opportunities it poses for rock engineering design;– the formal means by which the Structural Eurocode maintenance cycle proceeds;– the plans currently being developed for improving EC7 with regard to rock engineering design and construction;– the unique and vital opportunity for the entire international rock mechanics and rock engineering community to comment on the Code and make suggestions for its improvement."

Jan 1, 2015

By J F. Davies

A review is presented of the fundamental differences between the Superior and Churchill geologic provinces. Structure, lithology, grade of metamorphism and a single recent age determination suggest that the Flin Flon -Snow Lake and Lynn Lake belts are remnant blocks of originally Superior rocks lying within the Churchill province. Major mineral belts occur along the main boundary between the Superior and Churchill provinces (the Thompson -Moak Lake nickel belt) and within the remnant Superior blocks inside the Churchill province (Fiin Flon -Snow Lake and Lynn Lake). During the Hudsonian orogeny, metamorphic gradients must have existed across the Churchill-Superior boundary and between the remnants of Superior rocks and the enclosing gneisses of the Churchill province. It is possible that not only the unusual nickel deposits of the Thompson belt but also the base metal deposits of the Flin Flon -Snow Lake and Lynn Lake districts are due to redistribution, or diffusion and migration of metals to areas of lower-grade metamorphism during the Hudsonian orogeny.

Jan 1, 1964

By Mohammadreza Jalali

Alberta contains over 400 billion barrels of viscous crude oil in fractured carbonates but there is no viable extraction technology as yet. Petroleum geomechanics has become a vital part of the assessment of such hydrocarbon reserves, especially for naturally fractured cases, which are particularly challenging in terms of accurate recovery prediction because of joint fabric complexity and lithological heterogeneity. As a result of interconnected fractures, transport properties of fractures (mostly permeability issues rather than thermal effects) are affected by production and injection activities that change the pore pressures, temperatures, saturations, and effective stresses. Enhanced oil recovery methods involving massive amounts of fluid injection (hot or cold) at high pressure (pinj) may be used to mobilize and produce the oil; therefore, deeper understanding of the fractured systems is desirable. Pressure and temperature variations in a fractured reservoir change the in situ stresses in the reservoir and surrounding rocks; this affects fracture apertures, radically changing the bulk flow properties because flux rate is highly sensitive to aperture. Hence, coupled pressure, temperature and effective stress changes must be considered for fractured reservoirs under a thermo-hydro-mechanical (THM) coupling approach.A hybrid FDM/DDM coupled method is presented to couple pore pressure and stress around a fracture in an impermeable matrix block. Deformation and stresses are calculated in each time step and then fracture permeability, which is the most sensitive petrophysical parameter in fractured reservoirs, is updated based on the fracture aperture variation. This model is then verified with UDEC (Universal Distinct Element Code) which uses a discrete approach to cope with fractured rock mass behavior.

Jun 1, 2012

By F. Mackay, S. A. B. da Fontoura

"The theoretical solution for a viscoelastic well was presented by Gnirk and Johnson in 1964. From this an exercise was executed to validate the numerical simulation of a cemented salt well. The exercise comprised the geomechanical behavior through time of a cemented salt well, this was achieved using a finite element commercial software. This simulation showed the accuracy of the theoretical solution for viscoelastic materials such as salt rock. The theoretical solution presented elastic and viscoelastic analytic equations for the tangential and radial stresses. The equations for the elastic material (casing and cement) and for the viscoelastic material (salt rock) are presented here: Where equations 1a & 1b are the radial and tangential stresses of the elastic material; equations 2a & 2b are the radial and tangential stresses of the viscoelastic material; and a, r and b are the geometrical parameters explained in Figure 1. These equations are function of Pb, a stress time dependent factor that comes from the Burgers model of viscoelasticity. This is well explained in Gnirk and Johnson (1964) and for the sake of simplicity is not disclosed here. Po is the stress at section A-A’ dependent of the depth h."

Jan 1, 2015

By M. N. Pons, F. Ferrari, V. Houzelot, B. Laubie, A. Bani, Université de Lorraine-CNRS LRGP

"More than 400 plants in the world are able to accumulate nickel in their aerial parts at concentrations higher than 10 g per kg of dry biomass. Then, nickel (Ni) can be recovered from the biomass of these hyperaccumulator plants. Agromining is a chain consisting in growing such plants and recovering metal and has been developed thanks to the combined know-how of agronomy and hydrometallurgy. Plants can be grown on serpentine soils, containing rather high concentrations of Ni, on sterile heaps or on contaminated soils. This crop enables us to extract Ni from secondary resources, and to improve soil quality by lowering its metal content. For example, Alyssum murale can be grown at the field scale in the Balkans, at yields corresponding to 110 kg Ni per hectare.Hydrometallurgical processes have been designed from the lab scale to the pilot scale to produce nickel salts: ANSH (ammonium and nickel sulphate hexahydrate), nickel sulphate, acetate, etc. and so on. These salts are used for surface treatment and in the paint and chemical industry. Ni salts are prepared from ashes, after plant calcination. Processes are based on the conventional methods of hydrometallurgy: acid leaching followed by different precipitation steps. These processes will be presented, as well as the pilot scale design. A life cycle assessment has been performed and clearly shows the environmental interest of this approach as a potential part of an anti-erosion strategy. An economic assessment has proved process feasibility and the final step is the launching of a start-up. At the moment, the approach is widened to other metals (cadmium, cobalt) and rare earth elements (REEs)."

Jan 1, 2016

By Lorant B. Geller

Sixteen miners died tragically at the Paymaster gold mine at Timmins, Ontario in February, 1945, when a badly corroded hoist rope broke. The investigation of the Royal Commission that followed arrived at a number of recommendations (Investigations, 1947) aimed at avoiding future disasters of this kind. One consequence was the development, and legislated use in Canada, several decades ago, of powerful electromagnetic (EM) instruments for the nondestructive testing of mine shaft wire ropes. The authors have been involved for many years in the design, production, and testing of EM instruments (Geller and Udd, 1990 and 1992, Geller and Kitzinger, 1991, Geller et al., 1993). Since the mid-1990s particular attention was paid to the design and operational results obtained from the computer- controlled portable MagnographJ II wire rope tester (Geller et al., 1995 and 1998). In the present article the authors summarize further hardware- and software-related developments of this instrument. Further, an account is given of the results obtained from the most recent design known as the PermaScanJ testing system. This is also a computerized dual-function system. In it, however, the sensor head is designed primarily, if not solely, for permanent installation and for remotely controlled operation. This represents a basic departure from traditional designs, which were intended for ad hoc temporary installations. The remotecontrolled instrument described in this paper has now been in operational use for more than 4 years.

May 1, 2003

By Deni Côte, Marcel Vallée

"The Guide to the Evaluation of Gold Deposits reviews the successive evaluation steps in the domains of geology, engineering, and economics. The Guide analyzes, in a systemic perspective, the sequence of exploration, development, and evaluation work required to bring a mineral deposit to production. The aim is to identify the metal/mineralization losses and ore dilution that each work step contributes to the evaluation and mining process. The procedure allows one to maximize the income and profits of a mining operation, and to reduce the risks of financial losses tied to investment decisions in the mining sector. For greater efficiency, the criteria of reserve estimation and classification should be integrated with the evaluation steps and methods. At earlier stages of deposit development, when quantitative knowledge is available mainly on the geological axis, the term ""delimited mineral deposit"" should be used. The term ""reserve"" should be used only in an operating mine or in a mining project, when information in the geological, engineering, and economic domains is adequate to ensure technical and financial feasibility. ""Reserves"" are by definition ""mining reserves"". Each category of proven/probable reserves and measured/indicated deposits should be subdivided into two classes to express better the many steps of mineral valuation. The category of ""possible reserves"" shall be replaced by that of ""inferred mineralization"". This system, derived from the Australasian Code, can easily be integrated into current practices of the exploration and mining industry within a short timeframe. The proposal to develop the use of the margins of error of the estimates at a confidence level of90% should be viewed in a longer timeframe. Establishing the precision of the mineral inventories and distinguishing between categories and classes by means of the margin of error will require more work and a longer break-in period.SOMMAIRELe ""Guide d’évaluation des gisements d&apos;or"" analyse, dans une approche systémique, les travaux d&apos;évaluation et de mise en valeur des gisements minéraux dans l&apos;axe de la géologie, dans l&apos;axée l&apos;ingénierie et dans I ‘axe de l&apos;économique. L’objectif est d&apos;identifier la contribution aux pertes de métal et à la dilution du minerai des diverses étapes de l&apos;évaluation et de l&apos;exploitation du gisement. Ceci aid erra à maximiser les revenus et les profits, et ainsi, à réduire les risques départe financière que comportent les décisions d&apos;investissements dans le secteur minier. Pour atteindre ces objectifs, iI est essentiel de relier les critères d&apos;inventorie et de classification des réserves aux méthodes d&apos;évaluation des gisements. Aux stades antérieurs du développement minéral, lorsque les connaissances quantitatives ne s&apos;étendent qu’à l&apos;axe géologique, le terme ""gisement délimite"" sera utilisé. Le terme ""réserve"" ne sera utilisé que dans une mine en exploitation au dans un projet minier, lorsque l&apos;information dans les axes de la géologie, de l&apos;ingénierie et de l&apos;économique sera appropriée pour en garantir la faisabilité technique et économique. Chaque catégories des réserves, prouvée et probable sera subdivisée en deux classes pour mieux qualifier les niveaux d&apos;évaluation du projet. La catégorie actuelle des réserves possibles sera remplacée par celle des ""minéralisations inférées"". Plusieurs essais démontrent que le système propose, qui s&apos;inspire du Code australasien, peut facilement et rapidement s&apos;intégrer dans les pratiques de l&apos;industrie. II pourrait également contribuer à une standardisation des méthodes et des nomenclatures à l&apos;échelle internationale. La proposition d&apos;utiliser les marges d&apos;erreur des estimes au niveau de confiance de90%pour caractériser les estimations se situe dans une plus longue perspective. Cette application demandera des développement méthodologiques additionnels ainsi qu&apos;une période de rodage."

Jan 1, 1992

By George Efremidis, Markos Avlonitis, Elias C. Aifantis, Avraam Konstantinidis

"Nowadays, there is an increasing interest for realistic spring-block models capable of addressing precursor phenomena in catastrophic earthquake-induced landslides. By pre-defining the constitutive law between externally applied stress and induced local strain increments, the dynamic behaviour of the rock/soil slope can be studied by means of the distribution of slip events at the interface between the soil and the bedrock. It is shown that by relaxing the assumption of constant of externally applied stress rate and local strain increments, a robust 2D spring-block model can be formulated for studying triggered landslides. A cellular automaton is built in order to examine the dynamic behaviour and the stability of rock/soil slopes during the initiation of a landslide. The type and nature of the failure plane, as well as the triggering mechanism is studied. The different dynamic evolution modes of the slope can be mapped to specific shape parameters of the corresponding distributions of the incremental displacements. The proposed spring-block model can be used in order to understand, predict and minimize the impact of catastrophic landslides triggered by earthquakes.INTRODUCTIONEarthquakes have long been introduced as one of the major cause of landslides. Earthquake induced landslides are of great importance because they can cause considerable damage and life casualties. Existing analyses can provide landslide concentration, i.e. the number of landslide sources per square kilometer of surface area, as well as the distance from the earthquake source, which is related to the strength of shaking, the slope steepness, which is connected to shear stress, and finally the rock type, which is referred to material strength (Keefer, 1984). In spite of their great importance in social and economic life, earthquake-induced landslides are still considered as an open geotechnical problem. The dependence of the number and distribution of landslides on earthquake magnitude and ground shaking intensities is a crucial factor for the description and determination of the phenomenon. The hazardous types of earthquake-induced landslides, the most susceptible geologic materials and the reactivation of landslides originally triggered by nonseismic activity are some important topics for areas affected by landslides. Most of these areas present an irregular and asymmetric shape with respect to epicenters and fault ruptures, and also show a strong correlation with magnitude (Keefer, 1984, 2000). The number of landslides caused by an earthquake generally increases with increasing earthquake magnitude. Keefer (1984) presented a magnitude scale in order to quantify the number of earthquake-induced landslides. Malamud et al. (2004) have proposed an independent landslide-event magnitude scale on the earthquakes, based on the logarithm of the total landslides number associated with an event. The aforementioned studies try to relate the landslide magnitude scale to the visible effects of the triggering mechanisms."

Jan 1, 2015

By A. Kobzhanov, S. Saparova, S. Brochot, D. A. Mango

KATCO (an ORANO Mining and Kazatomprom joint venture) is the largest in-situ leach uranium mining operation in the world, exploiting the Muyunkum and Tortkuduk uranium deposits in southern Kazakhstan. After extraction from the deposits, uranium is then transported via a hydraulic network to be purified in three processing plants located near these deposits. Within KATCO, with the support of ORANO Mining and CASPEO, in 2018 and 2019, a large project that had as its main objective to improve the uranium accounting system was implemented. The objective of this paper is to describe this project and all the changes that it entailed. At KATCO plants, a black-box approach was previously used for uranium accounting. However, it is recommended to use all the available measurements and to deploy a data reconciliation model (between well-fields and plant) as the reconciliation uncertainty is overall lower and it provides a more accurate uranium balance. During the deployment of this project, the rules and algorithms to generate the uranium accounting report, the associated flow diagrams (for uranium accounting), the streams, units of operation, stocks, reporting and Key Performance Indicators calculation rules were re-defined.

Jan 1, 2020

By B. F. Giyani, D. Rahal

"Stirred media mills have proved to be more energy-efficient than the conventional ball milling for fine grinding applications. The mill performance is governed by a number of operating variables including mill stirrer speed, feed particle size, solids content and slurry rheology. A study was conducted to assess effects of mill speed, media size and density, and slurry density on the Stress Intensity (SI) in a VXPmill and thereby the relationship to mill performance. For the mill speeds tested, it was found that the optimum tip speed is 7 m/s. If the speed is too high (12 m/s) energy losses result due to mechanical friction losses and heat generation. If the speed is too low (3 m/s), the kinetic energy is not sufficient to promote breakage. The size reduction ratio increases with the increase in mill speed and the decrease in solids content especially in the coarse fraction particle sizes. The effect of slurry rheology on mill performance was shown by assessing the effects of increasing solids concentration and decreasing particle size. Rheological effects seemed to interact with mill speed such that the mill was less energy-efficient at higher solids content and at higher mill speeds particularly for grinding to fine particle sizes. There is an opti"

Jan 1, 2017

By T. G. Edgeworth

Some of the historical background of the industry is reviewed, with reference to the different types of reduction cells in use for aluminum smelting. Factors to be considered in cell des1gn involve capital, power, and operating costs. The trend is apparently toward larger cells. The industry is studying new construction materials for cell linings, as well as alternate electrolyte compositions and other design changes which will improve productivity and energy efficiency. The aluminum smelting activity in other countries is briefly reviewed. TODA Y'S industrial production of aluminum is still based on the simultaneous discoveries made in 1886 by Charles Martin Hall in Ohio, and Paul Heroult in France. Up to that date, only about 50 tons of aluminum had been produced in the world, and the price at that time was about $5 per pound. Sucl1 figures must be contrasted with the present world aluminum smelting capacity of over five mil-lion tons per year, and a price of about 25 cents per pound.

Jan 1, 1962

By José J. Suárez

As pressure grows for commodity pricing, new mines are more difficult to develop, the stock markets demand better financial returns from mining companies, resources for the developing and operations are scarce, and developing countries in Asia, and Africa demand more metals, it is important that mining companies effect better utilization of capital to develop capital projects. In the last few years, the costs for Capital projects have been impacted by the following factors:

May 1, 2013

By R. E. Bou Serhal

Many miners are exposed to dangerously high levels of noise on a daily basis. Over the past 15 years, a continually increasing number of occupational hearing loss has been reported from the mining community in the United States, of which, more than 95% is attributed to prolonged noise exposure. Although the noise exposure levels may differ between coal miners and metal and non-metal miners, in the absence of noise control at the source, the solution is the same: use of personal hearing protection devices (HPD). While protecting the miners? hearing it is also essential to no longer hinder their ability to communicate. With access to an advanced HPD that is customized to the miners? ears we are able to combine these two requirements. Using an intra-aural instantly custom molded HPD miners are protected from high levels of noise. The HPD is equipped with wireless capabilities, and contains both a speaker and an In-Ear Microphone (IEM). Therefore, the miners? speech may be captured from inside the ear and transmitted to the remote listener. This IEM signal is relatively noise-free since it is isolated from the background noise. The IEM speech signal, however, is ?boomy? and is missing some high frequency content, making fricative consonants hard to understand. Nonetheless, the IEM speech signal is correlated with the natural speech signal and may be manipulated through statistical techniques to more closely resemble natural speech. By improving the intelligibility and quality of the IEM signal, numerous applications may be enabled. One use of the enhanced IEM signal will be for radio communication. Using wireless radio communication in a noisy mining environment is sometimes the only practical and affordable solution to allow communication between miners equipped with personal hearing protection devices. Traditionally, one of the weaknesses of such wireless radio communication lies in the lack of designating receivers: whether they are the intended receiver or not, all those carrying a radio receiver are subjected to the broadcasted signal. The current work will detail a new concept of a "radio-acoustical virtual environment" where the radio signal will only be received by miners within a given spatial range, such range depending on the user?s vocal effort as well as the ambient and perceived background noise levels.

Aug 1, 2013

By Kenta Suzuki, Toshiya Anami, Daisuke Shimosaka

"In an Al-Mn alloy heat exchanger fin stock, the effect of annealing conditions for as-cast and 0.1%Zr addition on recrystallization behavior is investigated using metallurgical analysis. Refinement of post-brazed recrystallized grains in fin stocks with Zr addition are suppressed for long-time annealing. In 0.1%Zr fin stocks, there was a decrease in the number of fine a-Al(Mn,Fe)Si dispersoids for pinning of sub grain and grain boundary. In addition, relatively homogeneous distribution of Al3Zr dispersoids was observed with increasing annealing time in as-cast. Homogeneous distribution of Al3Zr dispersoids can have a major effect on pinning of sub grain and grain boundary during brazing heat treatment. The homogenous distribution of fine dispersoids prior to brazing heat treatment is effective in causing the suppression of refinement of post-brazed recrystallized grain structure in aluminum alloy fin stocks.INTRODUCTIONAl-Mn based alloys are widely used as fin stocks in automotive heat exchangers because of their superior mechanical properties, braze ability, sagging and so on. In particular, coarsening of recrystallized grain structure is beneficial to avoid erosion, and achieve excellent sagging resistance (Lee, Yoon, Kim & Jung, 2002). For resisting grain coarsening, the alloys should contain a dense and homogeneous distribution of fine dispersoids to retarder crystallization (Humphyreys& Hatherly, 2004). It has been demonstrated that addition of Zr to Al-Mn alloys can shift recrystallization to higher temperatures because of the distribution of fine Al3Zr dispersoids in matrix(Pokoba, Cieslar& Lacaze,2012). According to Tohma, Asanoand Takeuchi (1987), coarsely recrystallized grain structure was obtained in 3003alloy with Zr addition after heat treatment. However, fine Al3Zr dispersoids are usually heterogeneously distributed because of segregation during casting and low diffusion rate of Zr in aluminum. Therefore, a homogeneous distribution of Al3Zr dispersoids can be achieved through long-time precipitation annealing(Jia, Hu, Forbord& Solberg, 2008)."

Jan 1, 2018

By W. G. Jewitt

Introduction The use of the aeroplane in prospecting is already familiar to everyone connected with the mining industry. Apart from transportation companies, three organizations, the N. A. M. E., the Dominion Explorers, and the Exploration Department of the Consolidated Mining and Smelting Company, have made the aeroplane an everyday feature in every mining district in Canada. Its use has been demonstrated successfully in the mountains of British Columbia, but perhaps its greatest field lies in the Canadian Shield, where the numerous lakes and rivers afford an almost continuous series of landing places for aeroplanes, on floats in the summer and on skis in the winter. To the man who has travelled by canoe, toiling over fly-infested portages or held for days at a time, wind-bound, on the big lakes, the ease, speed, and cheapness of aeroplane travel have marked the beginning of a new era, in which ground previously covered with difficulty in a month or more is travelled with ease in a few hours. Development of an air service in the Consolidated Mining and Smelting Company has proceeded on different lines from those of other organizations, and this paper is concerned with that development.

Jan 1, 1931