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By Shiqiang (Rob) Hui, Jiaren (Jimmy) Jiang, Rees Llewellyn, Yongsong Xie

Wear has been estimated to cost the Canadian mining/mineral processing industry over $15 billion per year mainly for repair/replacement of worn parts in 2013. The associated production loss is difficult to quantify but add considerably to the problem. The Canadian oil sands sector which has to deal with extremely abrasive and erosive solids, has traditionally incurred extremely severe and often unique attack. Demonstrable progress in mitigating the wear problems has been achieved through materials development, more informed materials selections, and better component and operation condition designs. An integral contributor to these advances is a long-term collaborative research partnership between NRC and the mining/supply industry. In this paper, this continuing collaboration will be described. A main focus is to identify degradation mechanisms occurring in the most severe and important service applications and to correlate these findings with laboratory test data. Relevant abrasion and erosion (often combined with corrosion) properties have been established and correlated with composition and microstructures for all classes of resistant materials ranging from relatively soft elastomers to ultra-hard ceramics. A comprehensive wear properties database has been compiled. This capability has been instrumental in facilitating the development of improved materials, optimizing materials fitness/selection for service, wear failure analysis, and quality assurance.

Jan 1, 2015

By James L. Parks, David M. Kjos

"Significant increases in mill liner life and plant availability can be achieved by following guidelines that have evolved from over twenty years of practical experience with autogenous grinding (A0) and semi-autogenous grinding (SA0) mills. A0 and SA0 mill liner functions, performance criteria, designs, wear-resistant materials and maintenance procedures are reviewed. Operating practices that can lead to accelerated wear and breakage are discussed.IntroductionEfforts to improve the performance of liners for autogenous grinding (AG) and semi-autogenous grinding (SAG) mills began as soon as the modern, large-diameter versions of these comminution machines were first intalled in commercial plants twenty years ago . While concentrators with conventional circuits were typically running at 95010 or better mill availability, many of the new autogenous and semi-autogenous circuits were struggling to achieve 80% availability. Liner maintenance, which involves not only material and labour costs but also loss of production, was quickly identified as one of the major reasons for downtime.Today, liner designs and materials have evolved to the point where virtually maintenance-free liner life of two to three years is possible in autogenous mills and one year in the more severe operating conditions encountered in semi-autogenous mills. Of concern, however, is that hard-won lessons from the past sometimes seem to be forgotten or ignored during the design of new mills and the operation of existing mills. As liner suppliers, we are often confronted with performance problems that could have been avoided by applying well-publicized guidelines for liner design and materials selection.This paper provides an overview of AG and SAG mill liner functions, criteria for evaluating performance, designs, wear-resistant materials and maintenance procedures. Also, operating conditions that can lead to accelerated wear and liner breakage are discussed in detail."

Jan 1, 1990

By Michael L. Free, Shukla. Abhijeet

The short-circuiting tendency of a copper electrowinning cell (EW) based on the roughness of cathode deposits was investigated with varying parameters such as Cu concentration, guar concentration, current density, and temperature. A bench scale EW cell was set up to produce copper under conditions similar to industrial Cu EW. In addition, a statistical analysis and finite element analysis were performed to analyze the deposited thickness, surface roughness and maximum feature height. Interaction data for the cathode deposits suggest that current density and Cu concentration together affect the roughness of deposit more than the combined effect of guar and temperature. Model predictions of roughness were similar to experimental values. The predicted time to short-circuiting was similar to the measured time. This study provides an industrial relevant baseline against which new operating parameters can be compared.

Jan 1, 2014

By Y. Y. Yemelyanov, S. S. Gudkov, A. V. Boldyrev, A. V. Bogorodskiy, S. V. Balikov

"A series of tests to optimize pressure oxidation- carbon-in-leach process (POX-CIL) of goldbearing flotation concentrate with the addition of sodium chloride and activated carbon were carried out. Flotation concentrate which was generated during primary ores concentration from a large Russian deposit was used for these tests. The tests were performed with different concentrations of sodium chloride. It was found that the required sodium chloride concentration for gold leaching was 5 g/L. The tests performed with different additions of activated carbon showed that the amount of activated carbon should be at least 6% of the concentrate mass. The rate of sulfides oxidation was 67.7–99.8 %. The highest gold recovery was 98.6 %.INTRODUCTIONThe majority of gold-bearing ores are recommended to classify as amenable to cyanidation and refractory. Processes at elevated pressures and temperatures have become increasingly important in base metals hydrometallurgy (Lodeischikov, 1999, 2007; Naboichenko, Shneerson, Kalashnikova, & Chugaev, 2009; Thomas, 2005).Current pressure autoclaves – cyanidation flow sheets are capital intensive due to numerous circuits and the use of environmentally-unfriendly sodium cyanide. The use of halide-based lixiviants during pressure oxidation of precious metals can be a promising technique for refractory sulfide goldbearing mineral raw material hydrometallurgical processing (Fleming, 2002, 2007, Kotlyar, Meretukov, & Strizhko, 2005).In this paper, we presented the results of the research on finding the optimum process parameters of pressure oxidation using an adsorbent for a refractory gold-bearing concentrate. A proposed flow sheet involves (Bogorodsky, Yelelianov, & Balikov, 2012):1. Gold-bearing sulfides oxidation followed by precious metals dissolution and the formation of gold and silver chloride complex;2. Reaction of the precious metals chloride complex with a carbon-based adsorbent;3. Precipitation of precious metals onto the adsorbent by EW and smelting of cathode precipitates into Dore bullions.This process allows POX of gold-bearing sulfides, precious metals dissolution and their precipitation on the adsorbent to be executed in one single vessel. This study found that the most suitable lixiviant was sodium chloride. Fleming (2002) suggested that in the presence of a halide-based reagent (e.g. chlorine- ion reaction), the dissolution of gold during POX is achieved according to reaction 1:"

Jan 1, 2016

By L. Kilburn

A survey of 281 mineral exploration agreements examines the ratios among three ways that may be used to purchase an interest in a mineral property, viz: pay cash, pay shams and make future expenditures on the property. The dollar value of the future expenditures exceeds that of cash or shams by about nine times in most of the 110 agreements that contain cash-expenditure or share-expenditure components. Results suggest that cash and shams are treated about the same in terms of value. Buyers and sellers haw opposing priorities for the way that they prefer to purchase a mineral property. These opposing priorities should give rise to a perceived 50:50 balance between cash/share payment and future expenditures to satisfy the idealized situation described by most definitions of fair market value (FMV). This balance between cash/share payments and future expenditures appears to be rationalized in negotiations to a FMV when expenditures are nine times greater than cash and/or payments. On this basis, it is proposed that the FMV of a property may be determined by aggregating the dollar amount of the cash/share payments plus one-ninth the dollar value of future expenditures, as set forth in the respective purchase agreement, and proportionately applying such aggregate to full property value.

Nov 1, 2005

By P. Curry, H. G. Stephenson, B. Van Den Bussche

"Three Sisters Resorts Inc. currently owns a2035 acre (824 ha) parcel of land, which previously belonged to Canmore Mines Ltd. Approximately 50% of these lands, that are slated for residential, resort and recreation development, have been undermined for coal in one or more seams.Norwest Mine Services has been contracted by the developer to assess and advise them on any past mining activity that may be potentially hazardous to their development and offer solutions to how these hazards may be mitigated or avoided.The following paper deals mainly with the procedures put in place and accepted by the approval authorities, and the Staged approach to the Investigative Procedure that Norwest follows in the mining assessment and mitigation work for Three Sisters."

Jan 1, 1996

By Rong. G., T. Q. Lin, W. Du

Based on analysis of the evolutionary history of the valley in Baihetan, the mechanism of asymmetrical evolution, gradual migration-incision evolved from left bank to the right, is revealed in Baihetan river valleys. The process of in-situ stress evolution is carried out by using the Universal Distinct Element Code (UDEC). Consequently, the numerical results which indicate the main regulations of that stress field are as follow: (1) The phenomenon termed "high in-situ stress fold" appears in the bottom of the valley. With the maximum principal stress being 28-34 MPa, the stress increases significantly at a vertical depth of approximately 130 m. (2) The in-situ stress presents zonal distribution along the bank slope. It is apparent that the in-situ stress field consists of stress relaxation zone (SRZ), stress concentration zone (SCZ) and original stress zone (OSZ). The horizontal depth of stress relaxation zone varies from the left bank (roughly 200 m) to the right (about 120 m). Furthermore, the stress evolution of the left bank slope is studied. As a result, it is found that asymmetrical erosion contributes to the difference of the in-situ stress distribution as a critical factor, between the left bank and the right. And for an asymmetrical valley, the evolutionary process of in-situ stress field is a circular procedure, which includes the incision of valley, the accumulation of landslides and the migration of valley.

Jan 1, 2015

By J. I. Carroll, J. A. Walker

"Abstract - Camelback is a small (=200 000 tonnes), moderate grade (5%-7% Zn+Pb), volcanogenic massive sulfide deposit, which occurs within the Nepisiguit Falls Formation of the Ordovician Tetagouche Group. The host rocks are tuffaceous sedimentary rocks (Little Falls member) that overlie quartz-feldspar porphyritic tufflavas (Grand Falls member). The hanging-wall sequence comprises rhyolite of the Flat Landing Brook Formation, overlain by the Forty Mile Brook tholeiitic basalt. A dike of unaltered andesite was intersected beneath the massive sulfides, but was not found in the hanging-wall sequence in the vicinity of the deposit. The stratiform part of the deposit is made up of two, steeply south dipping, subparallel massive lenses that average approximately 4 m in thickness. Each lens is zoned, with an upper part consisting mainly of a pyrite and a basal part containing pyrite, sphalerite, and galena, with Ag values. The Au content in the massive sulfides is low (average = 52 ppb for 271 samples), but tends to be enriched in the massive pyrite near the top of each lens. Oxide facies iron formation is spatially associated with the massive sulfides, and has been traced up to 1800 m along strike. Footwall hydrothermal alteration is typical of VMS systems, and is characterized by depletion in K2O and Na2O, and enrichment in MgO and Fe2O3T with proximity to massive sulfides. The massive lenses are underlain by intensely chloritic, fine-grained, tuffaceous sedimentary rocks containing locally significant sulfide (chalcopyrite > pyrite > pyrrhotite) veins, which are interpreted to represent feeder zone mineralization. Unlike many VMS deposits, there is no evidence of silicification beneath the massive sulfides at the top of the feeder zone. The oxygen isotopic compositions (d18O = -1.5‰ to -0.3‰) of hydrothermal chlorite coupled with sulfur isotopic compositions (d34S ˜ 12‰) of the massive sulfides suggest that seawater was the dominant fluid in the hydrothermal system. Normalized rare earth element diagrams show flat Ce profiles and positive Eu anomalies, indicating that modified seawater was involved in ore formation; i.e., high-temperature (=350ºC), acidic, and reduced prior to entrainment into the hydrothermal cell. Although, seawater was the dominant fluid in the sulfide-forming system, d34S values of stringer zone sulfides (8.5‰) coupled with elevated Sn (400 ppm) in one massive sulfide sample indicate that there was at least some magmatic component in the hydrothermal cell."

Jan 1, 2006

By J. C. Gilbert

"IntroductionTHE PURPOSE of this paper is to discuss in a general way the heavy oil situation in Western Canada, and particularly to acquaint those in the oil industry who have not participated in the heavy oil end of the business with past and current developments. The author has covered •briefly the location of the heavy •and asphalt-base oil fields, their geology, current drilling and production practice, the location of the •refineries capable of handling heavy crude, their products and markets, and the problems and future prospects of the industry.Location and Description of FieldsThe term heavy oil is generally used to denote crude of 20.9° gravity and under. Since the products from heavy oil are also to a lesser extent obtained from asphalt-base crudes of higher gravity, some mention will be made here of the latter; but in general the emphasis of the paper is on heavy oil as such.In the order of their production to date, the heavy oil fields and those light oil fields which produce asphalt-base crudes are : Lloydminster, Taber, Vermilion, Conrad, Princess, and Wainwright.The Lloydminster oil field has not only produced most of the heavy oil, but also is currently the largest producer, supplying at the present time about 80 per cent of the heavy and asphalt-base crudes produced in Western Canada."

Jan 1, 1952

By S. A. Scott

In 1913, potash mineralization was recognized at a depth of over 7,000 feet in an oil-well hole (Norcanol's Radville No. 1 well) drilled near the town of Raddlle, Saskatchewan. Although, at this depth, potash is not considered mineable by conventional underground mining methods, this discovery shed the first light on the potash deposits of Saskatchewan in much the same manner as oil-well drilling was responsible for the first discovery of potash in the Carlsbad Basin of New Mexico in 19:25. The discovery near Radville alerted the oil-well geologists and, as a result potash mineralization was recognized in the Verbata No. 2 well, near Unity, Saskatchewan, in 1946. The mineralization, which was at a depth ?of 3,466 feet, graded more than 20 per cent K20 over a thickness of eleven feet. This discovery, as its depth, thickness and grade were all amenable to mining,

Jan 1, 1963

By John F. Kearney

After World War II Canada?s fledgling iron ore mining industry developed along the ill-defined Quebec / Labrador border near what became the town of Knob Lake and later renamed Schefferville. For about twenty-five years from 1954 to 1982 Schefferville was the epicenter of Canadian iron ore mining and the foundation of the Iron Ore Company of Canada. In about 1982 it all stopped, shut down, the miners moved away leaving behind a mining camp and a ghost town that have sat idle and almost deserted for the past twenty five years. The story looks set to change with new plans to re-establish the former mining operations in the historic mining camp. This paper outlines the proposal to reactivate the direct shipping iron ore operations in the Schefferville mining camp, and specifically the properties in Labrador owned or optioned by Labrador Iron Mines Limited (?LIM?), a wholly owned subsidiary of London Stock Exchange listed Anglesey Mining plc. The Schefferville mining camp is located about 1,000 km northeast of Montreal. There are no roads connecting the area to southern Labrador or to Quebec. Access to the area is by rail from Sept Iles to Schefferville, or by air from Montreal and Sept Iles.

May 1, 2007

By Margaret Anne Stephenson

Today, in Australia, it is increasingly common to see agreements between Indigenous peoples and resource companies being achieved generally as Indigenous Land Use Agreements or agreements pursuant to the ?right to negotiation? process under the Native Title Act 1993 (Cth). Despite progress in this area, resource development on Indigenous lands is not without its challenges for both the resource proponents and the Indigenous parties. History demonstrates that resource development on Indigenous lands has produced struggles between the traditional owners of the land and the resource proponents. In Australia their relationship is generally defined by issues of access to land and assuring continued access to the land for the life of the project. In this context, divisions in Indigenous communities often emerge. The proposed resource project can have the effect of polarising members of an Indigenous community. It may be regarded by some traditional land owners as an advantageous opportunity for the community and by others as a hazard to country and culture. The process of agreement making has proved not only a test for the Indigenous community but also for the resource proponent. In this paper we undertake a contemporary case study of a proposed Australian resource related-development project on Indigenous lands. This project involved a multi-billion gas hub precinct proposed at James Price Point in the Kimberley region in Western Australia. The James Price Point proposal produced a litany of challenges for all parties. The traditional owners faced fundamental social and human rights issues, including a minority opposition to the project, the project's potential cultural heritage impact, the threat of compulsory acquisition of their native title interest by a State government due to an initial failure to settle an agreement, a fracture of their unsettled land claim and a minority rejection of the agreement ultimately reached. Additionally, the ?green? lobby also rejected the proposed gas hub on environmental grounds bringing the green lobby into direct conflict with both the traditional owners in favour of the project and the resource proponent. Ultimately, Woodside announced its decision not to proceed with the proposed gas precinct at James Price Point, in April 2013. In this paper we analyse the complexity of the James Price Point gas hub negotiations with the traditional owners which resulted in an Agreement that promised to deliver substantial benefits for the Indigenous communities. We question why such a favourable and beneficial agreement for the Indigenous community also produced the plethora of challenges and concerns and we consider how future negotiation processes could be better structured to avoid the difficulties that have confronted Indigenous land owners and resource proponents alike.

Aug 1, 2013

By Vicki Tschirhart, Bill Morris, McMaster University

A new method for mapping faults within basement rocks underlying the Thelon Formation and glacial overburden was developed and tested in the Aberdeen Sub-basin. This method utilizes newly acquired aeromagnetic data, the Blakely algorithm for defining magnetic source edges, a calculated dip-direction map, a digital elevation model (DEM) derived from the Canadian Digital Elevation Database, and the positions of identified, inferred and newly mapped faults that are within and adjacent to this sub-basin. Combining these data revealed three age groups of faults. One group is seen only on the DEM; these faults are young brittle structures that have no effect on the sub-Thelon basement unconformity, and are not visible on the dip direction map. A second group is evident on the dip direction map but not the DEM; these faults are old basement structures that did not propagate upward through the Thelon Formation. The third group is expressed on both the DEM and dip direction map; these faults are also old structures that propagated upward during and/or after deposition of the Thelon Formation. The latter group of faults may be of greatest interest for uranium exploration, with reactivation increasing their potential to serve as conduits to transport uranium-rich fluids and focus deposition at or near the unconformity surface. This methodology has promise for comprehensive mapping of basin faults and tracking the tectonic development of the whole Thelon Basin through time.

Jan 1, 2013

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 R. P. D. Graham

It is almost exactly two hundred years since the foundations of the mining and metallurgical industries in Canada were laid. There '."'as nothing spectacular about this early start. It had to do with the most basic phases of these industries-the mining of coal and iron ore, and the manufacture of cast and wrought iron. At several points along the coast of Cape Breton island, coal seams may be seen outcropping quite conspicuously, and it is probable that they had been observed, and possibly worked in a small way, in very early times. However that may be, these coal seams have the distinction of being the first in North America of which there is any printed record, reference to them appearing in a volume by Nicolas Denys which was published in Paris in 1672. Regular coal mining in the district did not commence until about fifty years later, however. The metallurgists started their operations along the north shore of the St. Lawrence river. Here, at many points between Montreal and Quebec, are to be found deposits of bog iron ore, and in 1 730 a furnace for smelting such ore was established on the St. Maurice river. The St. Maurice forges continued in operation until 1880, and throughout that long period they were famed for the fine quality of castings produced, and also for a-superior wrought iron.

Jan 1, 1924

By F. Qi, T. Frišcic, C. Mottillo

"One of the principal goals of modern industry is to minimize the environmental impact and increase the materials- and energy-efficiency of transforming raw materials into valuable products. This paper will highlight our latest laboratory-scale research in low-energy, low-solvent reactivity of metal oxides and their conversion into popular metal-organic frameworks (MOFs), zeolitic imidazolate frameworks (e.g. Basolite® Z1200 component ZIF-8), and metallodrugs (e.g. bismuth subsalicylate, active component of Pepto-Bismol®). Mechanochemical ion- and liquid-assisted grinding (ILAG) and ""accelerated aging"" techniques will be presented, along with novel low-energy and solvent-free approaches, inspired by geological weathering processes, for converting metal oxides into metal-organic materials. INTRODUCTIONThe development of environmentally-friendly processes, which would in the same time be more materials- and energy-efficient than the existing ones, is one of the central concerns of modern chemical research. In that sense, the focus of the chemist has been mainly on the preparation of carbon-based organic molecules and adaptation of traditional organic synthesis to the recently delineated ideals of Green Chemistry. However, there is a growing realization within the chemistry community that significant energy, materials, and ecology-related benefits can be achieved and, indeed, targeted in the transformations of materials that are typically associated with inorganic chemistry and minerals processing. The principal aim of this highlight contribution is to illustrate how, through the use of approaches associated with solventfree chemistry and mechanochemistry (James et al., 2012), one can develop a clean and efficient system of chemical and materials transformations involving oxide precursors that normally belong to the realm of inorganic chemistry and mineral processing. In particular, this contribution will provide an overview of the recently developed mechanochemical and solvent-free reactivity of metal oxides towards small organic molecules. These mechanochemical reactions, including the methods of liquid-assisted grinding (LAG, Frišcic & Jones, 2009) and ion- and liquid-assisted grinding (ILAG, Frišcic, 2010), have so far provided a radically different means to construct advanced metal-organic materials (e.g. porous metal-organic frameworks, [MOFs] or metallodrugs) by rehabilitating metal oxides as precursors, eliminating the use of bulk organic solvents, and avoiding the use of high temperatures."

Jan 1, 2012

By K. Baris

Methane (CH4) present in coal seams, generally known as Coalbed Methane (CBM), Coal Mine Methane (CMM) or Coal Seam Gas (CSG), is a major energy source, as it is the primary constituent of natural gas. At the same time, released methane is a potent greenhouse gas (GHG) and a major safety hazard in underground mining operations. Therefore, a considerable effort has been undertaken to develop coal bed methane extraction and utilization technologies that can achieve both environmental and safety benefits. Countries with significant coal reserves and gassy seams, i.e., USA, Australia, Canada, China, India, Poland and Germany have developed mature methodologies and practices to extract, before and during mining, and utilize significant amounts of methane from coal seams. Nevertheless, on a global scale, methane recovery remains untested and many technical and economic challenges require urgent attention. The research presented in this paper, sponsored by the United States Environmental Protection Agency (EPA), is focused on the Zonguldak Basin, the only hard coal region in Turkey. The basin is known to contain very gassy coal seams and consists of three major regions: Armutcuk, Zonguldak and Amasra. Among the three, the Amasra coalfield is considered as the most favorable for CBM recovery, as it comprises of deeper coal seams and where a private company, Hema Enerji A.S. (Hema) is already developing coalbed methane production facilities. This study aims at developing a reservoir model to predict the potential CBM recovery from the CBM-2 well, the only producing CBM well drilled by HEMA Enerji A.S in the Amasra coalfield. History matching was utilized to model the 15-day production data and uncertainty analysis was performed to estimate the optimum values for the reservoir parameters. The produced model yielded an average production rate of 143 m3/day for 10 years. The total amount of CH4 to be produced during this period was 0.53 million m3. Furthermore, the total amount of GHG to be avoided was estimated at 6585 tCO2e.

Aug 1, 2013

By Marlin E. Sandlin

NORTH-CENTRAL United States is now, and will continue to be, a natural market for Canadian crude oil. This area is a natural market for many basic reasons. There are no physical barriers along the border of our countries. This market is in dose proximity to Canadian production. This market is already joined by crude oil pipe-1,ines to numerous producing areas of Canada. The tariff barriers are reasonable. We are not handicapped by mandatory quota restrictions. There are many of us who desire lo sell Canadian crude oil in this market. Further, and what is really important, there are many of us who desire to buy Canadian crude oil for this market. It is fundamental that for crude oil to be sold in the world market, it must ?be sold at competitive prices. At the same time, it is important that such competitive price must result in a fair price for the crude oil at the we1lhead. The factors of nearness to market, cheap pipe line transportation, and reasonable United States tariffs, all tend to make ?possible a competitive market and a fair wellhead price.

Jan 1, 1958

By A. H. Mumin, A. Prikhodko

"This paper provides an understanding of interpreting and evaluating airborne time domain electromagnetic (TEM) surveys as applied to massive sulfide exploration. Variations in the conductive morphologies of massive sulfide ore systems are discussed, followed by forward modelling exercises examining the derived TEM response to these morphologies and discussion of the subtleties of data interpretation. Deposit morphology in the orientation at formation and the variations occurring due to later deformation are considered. Images of corresponding resistivity–depth models are provided. The combined modelling results provide a low-cost method for initial interpretation and screening of TEM anomalies. RÉSUMÉ Cet article nous permet de mieux comprendre l’interprétation et l’évaluation des levés élec-tromagnétiques aéroportés en domaine temporel (TDEM, de l’anglais time-domain electromagnetic) appliqués à l’exploration du sulfure massif. Y sont débattues les variations au niveau des morphologies conductrices des systèmes de minéralisation du sulfure massif, suivies d’exercices de modélisation prospective qui examinent la réponse dérivée des TDEM à ces morphologies et d’une discussion sur les subtilités de l’interprétation des données. L’étude envisage la morphologie de l’orientation originelle non déformée des gisements ainsi que les variations résultant d’une déformation ultérieure. Des images des modèles correspondants de résistivité-profondeur sont fournies. Les résultats combinés relatifs à la modélisation proposent une méthode peu onéreuse d’interprétation et de contrôle initiaux des anomalies dans les TDEM.INTRODUCTION Electromagnetic geophysical surveys are an indispensable foundation of many mineral exploration programs and can account for as much as half of the predrilling exploration costs. Quantitative mass interpretation of the survey results remains difficult due to the infinite variation of deposit morphologies, their complex physical properties, and the presence of barren conductive materials that can mimic or mask the response of targeted ore. Many modern geophysical investigations that focus on time domain electromagnetic (TEM) data interpretations are devoted to problems with inversion and modelling and their algorithms. Although a few of these investigations have resulted in commercial software products, these require highly qualified and experienced users and usually include geometric assumptions. Furthermore, without the input of known physical properties and geometric constraints, the inversion results are highly ambiguous. A number of case studies document the geophysical responses to known targets in well-defined and diverse geo-electrical environments, providing a high degree of correlation between field obser-vation and the results of the modelling used in this style of investigation (Hone, 1980; Schneider & Emerson, 1980; Tyne, Idnurm, & Malone, 1981; Bishop & Lewis, 1992; Hopgood & Hungerford, 1994; Meju, 2002; Yang & Oldenburg, 2016). The uniqueness of the target/environment parameters and their specific features limits the use logy is poorly understood. The responses are therefore that are devoid of complicating environmental factors (e.g., highly conductive overburden and hostrocks or nonuniform target conductivity) as a first approach to the interpretation process of such case studies as the main reference for interpreting TEM survey responses in areas where the underlying geomodelled from generalized and typical geological models"

Jan 1, 2018

By J R. M Hutcheson

Advocate Mines Limited came into initial production on June 30, 1963, with an annual capacity in excess of 60,000 tons of high-quality chrysotile asbestos fihres, thus strengthening Canada's position in world production. The history of this development is traced from discovery through initial exploration, financing, orebody delineation and evaluation, pilot-plant production and product evaluation, construction of the plant, construction of deep?-sea shipping facilities, provision for a closed shipping season, and provision for the remoteness and for the lack of services, through to realization of full production capacity. The many unique aspects of the project are given special attention, particularly in the light of the first year of full-capacity operation. The marketing of the products in a highly competitive world market is reviewed, with special emphasis on product evaluation, quality control and the shipping of high-quality products to consumers throughout the world. C ANADA'S newest asbestos producer, Advocate Mines Limited, is located at the north end of the Burlington Peninsula, White Bay District, Newfound-

Jan 1, 1965