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By Bern Klein, Malcolm Scoble, Justin Widdifield, Andrew Bamber

"It has been suggested that the pre-concentration of ore underground can bring positive economic and environmental benefits to underground mining, particularly at extreme depth. The integration of mineral processing systems for coarse waste rejection and disposal into the underground mining environment has a substantial impact on the economics and operation of the mine. A case study for the integration of underground pre-concentration at Falconbridge’s Thayer Lindsley and Fraser Copper operations in Sudbury, Ontario is discussed, with particular focus on ore evaluation, system design, integration, and impacts on the operation. Conclusions as to the overall feasibility and potential impacts of underground pre-concentration are presented.INTRODUCTIONObjectivesA scoping investigation has been conducted for Falconbridge Ltd on the Fraser Copper Zone and Thayer Lindsley mines in order to develop a better understanding of the operations, and to do a preliminary evaluation of the potential for pre-concentration of the ore underground. The objective was to develop a conceptual design and evaluation of a pre-concentration system for each site. The results are to be used as the basis for a more detailed future study.Underground Pre-ConcentrationThe pre-concentration of ore to reduce the quantity and improve the quality of material transported to the processing plant is not a new concept and has been in practise at several mines including the American Zinc Company in Mascot Tennessee (Munro et al, 1982), the Sullivan Mine in British Columbia and presently at Xstrata’s Mt Isa lead-zinc mine in Australia, as well as at several PGM mines operating in the South African Bushveld. For each of these mines, a high degree of waste rejection was achieved at a coarse particle size with good metallurgical recoveries. The benefits arising from the surface pre-concentration of ore are well documented in the literature (McCullough et al, 1999; Miller et al, 1978; Munro et al, 1982; Schena et al, 1990; Sivamohan & Forssberg, 1991)."

Jan 1, 2006

By K. J. Daun, C. J. Shi

UsiborThrough the second step heating at 900 °C, the spectral emissivity shows a gradually decreasing trend with increasing soak time, caused by the surface phase transformation from Al® 1500P coupons are austenitized in a Gleeble 3500 thermomechanical simulator using a two-step heating procedure in an argon atmosphere. Variations in spectral emissivity are measured in-situ using a near infrared spectrometer and ex-situ with a Fourier transform infrared reflectometer. Microstructural evolution and surface roughness are investigated using optical microscopy, FE-scanning electron microscopy, and a surface profilometer. A series of phase transformations of Al-Fe-Si intermetallic phases at the coating/steel substrate interface cause the surface phase and surface roughness to change, which in turn influences the spectral emissivity. At the beginning of the first heating step, the coupons have very low spectral emissivity, due to the molten Al-Si coating. Spectral emissivity increases significantly with increasing soak time from 5 to 12 minutes, associated with the surface phase transformation of the coating into Al7Fe2Si intermetallic phase and an increase in surface roughness. 5Fe2 into AlFe intermetallic phase with a decrease in surface roughness.

Jan 1, 2015

"4.1. IntroductionThis chapter reviews the geochemistry of the platinum-group elements (POE) in sulphur-poor silicate rocks, and the limited data on POE in silicate, oxide, sulphide, arsenide and sulpharsenide minerals. The earliest geochemical studies of POE in silicate rocks, minerals and meteorites were carried out mainly by Goldschmidt, the Noddacks and their co-workers, and are reviewed in Crocket (1969). These researchers established the siderophile character of the POE, emphasized the common association of the group with sulphides in ultramafic-mafic rocks and suggested that very low concentrations of POE are typical of sulphur-poor silicate rocks and minerals. Much of these data were for Pt and Pd only and are more than 50 years old. Because of the poor sensitivity typical of the available analytical methods, few reliable data were obtained on silicate rocks in these early studies. Surveys of POE geochemistry demonstrate that the data base for sulphur-poor silicate rocks is very restricted, although considerable highquality data for Pd and Ir have been accumulated (Wright and Fleischer 1965, Yushko-Zakharova eta/., 1967, Mertie 1969, Crocket 1969, 1979, Keays 1981).Two recent publications, Vol. 71, No. 7 (1976), of Economic Geology (An Issue Devoted to Platinum-Group Elements) and Vol. 17, Part 2 (1979), of The Canadian Mineralogist (Nickel-Sulphide and Platinum-Group-Element Deposits), are of special interest. These volumes are clear testimony to the impressive progress made in the last decade toward describing the mineralogical and geochemical aspects of POE ore deposits, but at the same time demonstrate the constraints in modelling POE ore genesis due to our meager knowledge of the. POE content and distribution among minerals in the source rocks of ultramafic and mafic magmas. It is clear that the phases hosting POE in mantle source rocks are poorly understood. Nevertheless, Naldrett and Duke (1980) have shown that the absolute and relative concentrations of POE in magmatic sulphide ores are related to the degree of partial melting of mantle peridotites, and subsequent processes of batch equilibration and fractional segregation of sulphides."

Jan 1, 1979

By R. R. Klimpel

"SYNOPSISA discussion of the importance of flotation rate in the analysis of mineral flotation is presented. In particular, the highly interactive nature of the flotation ""system"" is emphasized where there are components of chemistry, equipment, and operating conditions simultaneously involved. It is further shown that: 1) flotation rate must be measured in order to economically optimize the performance of an industrial flotation circuit, 2) that consistent patterns exist in both flotation rate and equilibrium recovery when changing various settings of the system components, 3) that knowledge of these patterns is necessary in order to avoid making system changes that are either self-compensating or dramatically re-enforcing in some particular aspect of performance, and 4) the rate related role of the chemistry component (e.g.frothers and collectors) is often much bigger than is sometimes realized (especially in a negative sense involving overdosing of reagents). INTRODUCTIONFroth flotation is widely usedl-6 in mineral beneficiation processes as a method for separating different types of finely divided solids present in a liquid (usually aqueous) suspension. The approach is based on the contacting of solids with upward moving air bubbles in an agitated vessel where the solids are exposed to chemicals (collectors) which create a condition favoring the attachment of a certain portion of the solids to the air bubbles. This selected portion is then removed in a froth stabilized by chemicals (frothers) and subsequently recovered from the flotation vessel. Depending on the settings of the various components of the flotation ""system"" (see Figure 1) it is possible to achieve a wide range of flotation performance."

Jan 1, 1984

By Jacek Paraszczak

L?exploitation rentable des gisements de type filonien constitue un problème important dans le contexte actuel de l?industrie minière québécoise. Les études effectuées depuis 1994 ont indiqué, que la technologie d?abattage mécanique utilisant l?outil hydraulique appelé « éclateur radial-axial » constitue une alternative intéressante par rapport aux méthodes conventionnelles par le forage et sautage. Les essais du prototype de l?éclateur ont prouvé qu?il est en mesure d?abattre les roches dures dans un environnement minier, mais sa performance dans les termes de masse du roc abattu dans une unité de temps a soulevé certaines doutes. Pour cette raison, une étude de préfaisabilité de l?éclatage en tant qu?une technologie d?excavation souterraine a été réalisée. Cet article présente quelques résultats des travaux effectués dans le cadre du contrat octroyé à l?Université Laval par le Ministère des ressources naturelles du Québec. Leur objectif principal consistait à comparer, pour les conditions des gisements filoniens, la productivité et les coûts des méthodes d?exploitation souterraine utilisant l?éclatage par rapport à celles conventionnelles. Deux variantes proposées de cette méthode ont été comparées avec la méthode conventionnelle sur le plan du coût (par tonne de minerai) et de la teneur de coupure de minerai d'or. Les études ont démontré que l?application de l?éclatage représente un potentiel de réduire ce coût, surtout dans les situations où l?abattage sélectif pourrait avoir lieu. Pour le cas de base on a trouvé, qu?il serait possible de réduire la teneur de coupure par la marge d?environ 16 ? 26%. Toutefois, les études de sensibilité ont démontré, que le coût dépend de façon important de la productivité d?éclatage, qui, pour sa part, varie beaucoup en fonction de paramètres du massif rocheux devant être abattu.

Oct 1, 2001

By S. Fuentes, J. Cáceres

"During the past fifteen years, mines utilizing the block caving method have improved performance and systematically reduced total mining costs.This paper describes improvements in mine design, mine planning, and mine management, including methods enabling the Chilean and international mining industry to ensure cost savings and productivity growth while using the block caving method. These improvements have encouraged the re-evaluation of underground operations at operating and closed open pits, and challenge surface mining applications as the only low-cost mining method. This paper describes a strategy to estimate the optimum open pit to underground transition time during the life of a mine. IntroductionDuring the last fifteen years, block caving mines have experienced huge changes in designs, planning and administration. These changes have permitted operators to drastically reduce costs, improve equipment productivity, and improve overall business performance. As a consequence of this situation, the block/panel caving mining system is challenging actual open pit operations to maximize the net present value (NPV)."

Jan 1, 2004

By Rajiv Kalra, Ji Jiangang

"This paper reviews the following aspects of the world’s largest manufactured Grinding Mill’s in terms of diameter and power, along with the world’s biggest shop assembly and trial run of the mills delivered to Sino Iron Magnetite Project in Australia.1. An overview of the basic flow sheet of the Sino Iron (Magnetite) Project located in Australia2. An overview of in-house designed CITIC Heavy Industries 12.2 m (40ft) F x 11 m(36ft) LG – 28MW AG mills including FEA and major components3. In-house manufacturing at CITIC-HIC work in Luoyang China of all major components for 6 off Ø12.2 m(40ft) AG mills and 6 off Ø7.9 m(26ft) x 13.6 m(44.6ft) LG – 2 x 7.8 MW Ball Mills4. Major aspects of design and preparation of the biggest shop trial run of Ø7.9 m(26ft) x 13.6 m(44.6ft) LG Ball Mill witnessed by international EPCM’s and clients in July 2009.5. Major aspects of one piece assembly of 1300 tonne rotating element of the Ø12.2 m(40ft) x 11 m(36ft) LG AG Mill and Ø7.9 m F (26) x 13.6 m(44.6ft) LG Ball Mill at the port of the export China and transport to Australian Port and then to site.6. An insight to unique installation methods used for Ø12.2 m(40ft) and Ø7.9 m(26ft) rotating element lifting on the mill foundation in one piece assemblies.7. CITIC Heavy Industries present capability for in house design and manufacture of Grinding Mills up to Ø13.7 m (45 ft) with 35 MW Gearless drives and Ø12.2 m(40ft) with 2 x 10 MW Geared Mill drives"

Jan 1, 2012

By J. K. Gowans

"INTRODUCTIONTo bring a mining property into production in the Canadian High Arctic a company must deal with the harsh environment, the short shipping season and the high cost of labour. In trying to minimize the effect of these factors, the concept of a barge-mounted process plant was investigated as an alternative to the conventionally built concentrator. Cominco's previous experience gained at the Black Angel Mine on Greenland's west coast suggested that this would be a practical alternative.The normal shipping season at Little Cornwallis Island is approximately six weeks long, from mid-August to the end of September. All equipment and materials must be delivered during this small ''shipping window."" The logistics problems are enormous; if the conventional approach had been used the major process equipment would have been delivered to Little Cornwallis Island at the same time as the completed barge actually was! Construction would also be starting at the start of the worst climatic conditions, the Arctic winter. Nine months production was gained by opting for the ""Barge"" approach.What the Arctic winters do to the shipping season, so do they affect the productivity and the cost of labour. Construction labour must come from southern Canada. Thus higher transportation costs and higher wage rates, with more overtime and incentives, increase the labour costs to approximately 50% over normal southern rates. Couple these rates with the lower productivity involved with men working in the extreme cold temperatures and the net effort is worth avoiding. A process plant being constructed in Southern Canada can take advantage of more accessible labour at lower costs, increased productivity and a faster construction schedule. The barge concept must still deliver the equipment and materials during the ""shipping window"" but it can in the completed form."

Jan 1, 1983

By Turcotte. Yves-Laurent

Notre conférencier, Monsieur Yves L. Turcotte, Vice-président et Directeur général chez Promaintech Novaxa est diplômé en génie industriel de l?Université du Québec à Trois-Rivières et détient une maîtrise en gestion de projets de l?Université du Québec à Montréal. Il est une véritable sommité canadienne dans le domaine de l?amélioration de la performance des organisations. Provenant d'entreprises manufacturières et de services, il possède plus de 20 ans d?expérience en tant que développeur de technologies, conseiller et formateur auprès d?entreprises. Il a à son actif la réalisation de mandats dans plus de 400 entreprises. Il est reconnu pour sa grande capacité d?analyse et pour trouver des solutions novatrices et profitables aux problèmes des organisations les plus complexes. Aujourd'hui, il dirige Promaintech Novaxa, une division de DMR, qui a célébré son dixième anniversaire en 2006. Cette organisation ayant des places d?affaires dans la région de Montréal, Québec et Vancouver compte plus de 50 professionnels et a une carte de visite dans 16 pays. Les axes d?intervention sont le Management, la Productivité, la Fiabilité, l?Innovation et l?Amélioration Continue.

Feb 1, 2008

By M. Gaumont, F. Robichaud

"Agnico Eagle Mines Limited (AEM) is a Canadian-based gold producer with operations in Canada, Finland and Mexico. In 2010, AEM produced its first gold bar in Nunavut, Canada as it started its Meadowbank operation. It is also in 2010 that AEM acquired the Meliadine property, which is located 25 Km North of Rankin Inlet, Nunavut, Canada. The Meliadine gold project is an advanced exploration and development project, comprising of workers camp, underground and open mines, a processing plant and all the services facilities and infrastructures required to sustain operation in a remote arctic environment.Pending formal board approval, production start-up is planned for Q3 2019 and the process flowsheet is based on an ore processing rate of 1.1 million dry tonnes per year (3,000 dry tonnes per day from underground mining) for the first three years, and 1.98 million dry tonnes per year (5,000 dry tonnes per day from both underground and open pit mining) for the remaining years at 92% process plant availability.To the end of 2015, more than 45 metallurgical test programs have been conducted on the Meliadine deposits. Based on the results of these programs, an optimal gold circuit was designed, comprising of crushing, grinding, gravity separation and cyanide leaching with a carbon-in-leach circuit (CIL), followed by cyanide destruction and filtration of the tails for dry stacking. The assumed gold recovery for the reserves averages 96.0% at a 7.44-g/t gold average mill feed grade."

Jan 1, 2016

Stress induced, gravity-assisted failure processes typically dominate long before stress levels approach the strength of the intact rock (at approximately smax > 0.4UCS where smax = 3s1 ? s3 and UCS is the Unconfined Compressive Strength of the intact rock (Martin et al. 1999)). Under these conditions, discontinuities typically become clamped and the failure process becomes brittle. This brittle failure process is dominated by new stress induced fractures growing subparallel to the excavation boundary. While it is possible to identify areas with the potential for brittle failure, for example, using the general assumption that brittle failure will occur in areas at right angles to the major principal stress (Hoek et al., 1995), when the threshold smax > 0.4UCS is reached in areas around the tunnel boundary, or elastic modelling and the Hoek-Brown brittle parameters proposed by Martin et al., (1999) (i.e. m? 0 and s ? 0.11), amongst others, recent observations discussed by Everitt & Lajtai (2004), and Kaiser (2005; 2006) suggest that brittle failure processes are enhanced when structural features such as joints, weakness zones, bedding planes or foliations are preferentially orientated around the excavation boundary creating stress raisers which in turn facilitate the stress-driven rock mass disintegration process (e.g., as illustrated by Everitt & Lajtai (2004) on Figure 1b). Such weaknesses induce stress heterogeneities that thus promote tensile-spalling failure processes (Diederichs 2000). The observations suggest that stress induced damage can occur ?prematurely? depending on the orientation of micro and macro structures in situations where the known stress conditions should not yet initiate brittle failure processes. In general, when structural features (micro and/or macro), especially foliations, are present in a rock mass, the strength is effectively reduced, largely due to tensile strength heterogeneity in areas depending on the orientation of the structural features with respect to the excavation boundary. As a result, stress induced damage could occur in areas not normally considered due to the influence of anisotropy (Figure 1).

May 1, 2009

By Dale Dean, Bill Hancock, Raul Mondragon, Carlos Aguilar, Chris Martin

"In 1942, commercial mining operations began in what is now the Lucky Friday Ag/Pb/Zn mine in Idaho’s Silver Valley. Wholly owned since 1962 by Hecla Mining Company, the mine has produced more than 145 million ounces of silver and has been a mainstay producer in Idaho’s Silver Valley for over 70 years.However, by the early 21st century, the mill had fallen, technologically, seriously behind the rest of the industry. Accordingly, starting in 2005, the current mill management team set to revitalizing the milling operation. This paper will describe how the mill was systematically evaluated and the aging infrastructure replaced with more current technology. Driven by internal mill review studies supported by QEMSCAN mineralogical balancing, the mill has in recent years been through waves of upgrading – from the installation of new mechanical and column flotation equipment to the introduction of on-stream analysis, a technology well-accepted around most of the industry but alien to this technologically conservative mining district.The experience at Lucky Friday is a testament to the need for ongoing structured mill optimisation and technology upgrading in established mining operations. This paper will describe engineering experiences associated with upgrading equipment in an operating mill, contained in a confined building. Experiences in teaching the team new ways of operating a mill, and finally the metallurgical rewards that have been reaped will be described.INTRODUCTIONMining in Idaho’s Silver ValleyIdaho’s Silver Valley is a 64-km long valley flanked by the US Northern Rocky mountains, seldom more the 3-km wide, and stretching across much of Idaho’s northern panhandle, roughly 150 km south of the Canadian border. Mining has been continuously active in the area for more than 140 years, during which time, the Silver Valley has become one of the richest silver producing districts in the world, and as of 1985 had out-produced the 500 years of production from the famed Potosi district in Bolivia. Since 1885, almost 100 deposits have been discovered and worked in the district (Chapman, 2000)."

Jan 1, 2011

By W. Roy Dunbar

"The Porcupine area is in northern Ontario at the intersection of N. Lat. 48° 30' and 81° W. Long. It is 125 miles due north of the Sudbury nickel range. Practically all the mineral production of this area has come from the townships of Tisdale, Deloro, Whitney, and Ogden, in order of importance. The accompanying map of the Porcupine area and its extensions to the east and west (Fig. 4) has been included to show what I consider to be an essential objective of this paper, a perspective for exploration.The discovery of gold ore in the Porcupine area at such an early date resulted from the extension of the Temiskaming and Northern Ontario railway and exploratory survey lines north into unexplored territory, for the early history of Porcupine is inextricably tied to the exploration along Niven's survey lines and the extension of the railway north from Cobalt to Nellie Lake. The following are the more significant events leading to the discovery of gold in Porcupine.1896-E. M. Burwash, employed by the Ontario Bureau of Mines, examined the country along Niven's base line and noted quartz veins that carried traces of gold. He was attached to Niven's survey party.1899-The late W. A. Parks reported on the geology of the portage route from Mattagami river to Night Hawk lake, for the Ontario Bureau of Mines. He noted the occurrence of gold in quartz veins and reported “I regard the region south of the trail to Porcupine lake as giving promise to the prospector"". He also was attached to Niven's survey party.1901-Charles Camsell, while prospecting for the Algoma Central railway, did some work on a vein occurrence carrying low gold on ground now known to be part of the Hollinger mine (3).1907- Extension of the Temiskaming and Northern Ontario railway to Nellie Lake.1909- Bannerman followed up Indian story about occurrence of coal, and found iron formation. He remained to prospect and found the gold-bearing vein of the Scottish Ontario property."

Jan 1, 1954

By H. J. McQueen

Before 1950, hot working was simply deforming above the recrystallization point and gave a soft product compared to cold working. From 1960 onwards, improved testing in compression and torsion (stress, strain rate, temperature, quenching) provided valid specimens for microstructural analysis by polarized optical and transmission electron microscopy (TEM). Indeed, TEM was essential to uncovering the hot working mechanisms because it could distinguish between cold and hot substructures (dynamic recovery) in either initial or new grains (dynamic recrystallization). Over the years, teams at Concordia, McGill and UBC obtained NSERC support for students and equipment. CANMET built up a hot forming group having capabilities from high-rate cam-plastometer compression to rolling of experimental alloy billets; this was combined with latest metallographic instruments for fundamental research. Al alloys of every class (2000, 3000, 5000, 7000, 8000) were studied to understand the effects of solutes, precipitates, dispersoids and composites. The complex flow patterns in extrusion were clarified and modeled by finite element methods. Physical simulations of rolling schedules (up to 20 passes and reductions of 98%) by torsion provided evidence of microstructure development during both the passes and the softening intervals, thus clarifying development of texture in different alloys. The results frequently appeared in proceedings of Light Metals symposia and Canadian Metallurgical Quarterly

Jan 1, 2011

By Tim Martin, Dave Tahija

"In April, 2014, Hecla's Greens Creek mill, near Juneau, Alaska, switched from sulphuric acid to the use of dissolved carbon dioxide for lead flotation circuit pH control. The Greens Creek mine uses paste backfill, in which mill tailings are mixed with cement and used to fill mined areas. Some backfill inevitably becomes part of mill feed during subsequent mining cycles, resulting in high feed pH levels and increased dissolved calcium in the lead flotation circuit. Sulphuric acid is traditionally used to lower pH in such cases but it produces undesirable side effects, including poorer lead-zinc separation and unstable froth. The amount of sulphuric acid used at Greens Creek was limited due to these effects, resulting in higher than target pHs when feed backfill content was high. Dissolved carbon dioxide can be added without these limitations so pH levels have been under much better control since the switch. Additionally, lead-zinc separation and froth characteristics have significantly improved.IntroductionThe Greens Creek Mine, owned by Hecla Greens Creek Mining is an underground mine located on Admiralty Island near Juneau, Alaska, producing silver, gold, lead and zinc in the form of lead and zinc flotation concentrates and a gravity gold concentrate (McDonald, Morgen & Hancock, 2012). The lead and zinc concentrates are produced in conventional flotation circuits preceded by a graphite removal flotation step.The underground mine utilizes cemented paste backfill, of which a certain amount is inevitably re-mined in later mining cycles and returned to the mill, mixed with fresh ore. The Portland cement used in the paste backfill is highly basic so that, from the point of view of the mill, the net effect is to introduce a good deal of lime to run-of-mine mill feed, producing a very high natural pH. This high pH needs to be lowered to obtain good metallurgical results."

Jan 1, 2016

By Yves Gratton

The International Commission on Large Dams (ICOLD) is a non-governmental International Organization which provides a forum for the exchange of knowledge and experience in dam engineering. It is the world's leading professional organization dedicated to advancing the technology of dam engineering and supporting socially and environmentally responsible development and management of the world's water resources. ICOLD was founded in 1928 and has National Committees in 82 countries with approximately 7,000 individual members who are engineers, geologists and scientists from governmental and private organizations, consulting firms universities, laboratories and construction companies. Its original aim was to encourage progession in planning, design, construction, operation and maintenance of large dams and associated civil works by collecting and disseminating relevant information and by studying related technical questions. Since the late sixties, focus was put on subjects of current concern such as dam safety, monitoring of performance, reanalysis of older dams and spillways, effects of ageing and environmental impacts. More recently, additional subjects have included cost studies at the planning and construction stages, harnessing international rivers, information for the public at large, and financing.

May 1, 2002

By K. Duckworth

"AbstractA new electromagnetic depth sounding technique was applied to the measurement of salt thickness above the workings in the Central Canada Potash Mine at Colonsay, Saskatchewan. The initial tests indicate that this new technique can measure salt thickness and that the technique possesses operational feature s which make it possible to monitor trends in salt thickness throughout the mine. The technique can be applied using existing equipment, but the tests do indicate the desirability of developing equipment with features specially suited to the mine environment.IntroductionTESTS were conducted in the Central Canada Potash Mine at Colonsay, Saskatchewan during 1974 and 1975 to determine if a new technique in electromagnetic depth sounding could provide a convenient means of measuring salt thickness above the workings. This new technique, which was described by Duckworth (1975), offers operational features which appear to be advantageous in this particular situation.The problem requires that soundings be made upward from the mine workings to the base of the second red shale. This shale forms an impermeable seal on top of the Prairie Evaporite. A knowledge of this salt thickness is of interest due to the need to avoid any possibility of the workings rising to cut the red shale. Another desirable objective is the detection of any disruptions of the red shale. Ideally, this should be done ahead of the workings in order that such areas of disruption may be avoided."

Jan 1, 1977

By J. B. Brodie, C. Pelletier

"The vulnerability of Canadian and U.S. companies, their directors, officers and employees to onerous penalties associated with violations of environmental statutes and common law actions has provided the impetus for the increasing use of environmental audits. This trend is developing in direct proponion to the cost and difficulty of obtaining liability insurance. Companies operating in British Columbia should be cognizant of developing legislative and enforcement trends and their implications for individual and corporate responsibility. Canadian mining companies doing business in the U.S. should be particularly aware of the environmental exposure which may be assumed with property acquisition or by operations which produce or use any of an ever-increasing list of regulated substances.The environmental audit is now a key component of prudent business planning which will identify noncompliances and environmental liabilities, outline defensive strategies, and assist in a legal defence should charges be laid. This paper will discuss the purpose and mechanics of an environmental audit with emphasis on those features which will maximize protection against statutory and common law actions.IntroductionThe environmental audit is but one weapon in a comprehensive defensive strategy for corporate and individual survival in an increasingly litigious world. The principles of the environmental audit have been formulated as a logical response by management to an ever-growing list of environmental vulnerabilities, which often have the potential to result in plant shutdowns, prosecutions or fmancial liability of major proportions. Accordingly, the audit may play a critical role in maintaining profitability as well as assisting in the defence of a company and its employees against actions taken by regulatory agencies and citi7.cns under statute and common law. Should convictions result from these actions, the penalties are likely to be ameliorated by the demonstration of due diligence through management policy supporting the audit procedure.An awareness of environmental sensitivities, strict adherence to licensing requirements, and planning for environmental emergencies are now generally considered to be as important to profitable performance as operating costs, metal prices, and labour peace. Why is this so? The increased priority given to environmental matters is partly a result of changing attitudes amongst the mining profession, but perhaps more importantly, it is also a direct consequence of the proliferation of ever more stringent environmental legislation, the targeting of management for responsibility and the draconian penalties imposed for violations of such legislation. Contributing to this trend are recent court decisions involving disputes of an environmental nature in which the standard of care required for a successful defence now requires almost super-human diligence in environmental management. The principle of ""strict liability"" (in which negligence or permit violation does not have to be shown) is also being increasingly applied in the resolution of civil actions."

Jan 1, 1988

By L. E. Djingheuzian

Introduction For many years the immense deposits of bituminous sands of northern Alberta have been attracting the attention of our governments, engineers and .scientists ( 6). Undoubtedly these bituminous sands represent one of the greatest potential resources of liquid fuels in the world. However, their commercial development has been retarded by the complexities of the technological problem and by the economic factors involved in the processing of the sands. The technological problem has been attacked from several angles ( 2, 3, 1, 11), and cold water separation of bitumen is one of them. To the ore dressing engineer, the cold water process is of utmost importance since, by the use of standard ore dressing machinery, it accomplishes most efficiently and economically the separation of bitumen from bituminous sands. The significance of using ore dressing equipment was especially enhanced by the fact that the scientific principles which underlie the design of standard machines were demonstrated in the cold water separation process with an extraordinary clarity. This greatly facilitated the analysing of limitations and advantages of different machines during-the pilot plant investigations and helped to complete the investigations practically in the allotted time.

Jan 1, 1952

By Jean-François Dorion

La corrosivité des environnements miniers souterrains est un phénomène peu étudié au Canada. En plus de détériorer les systèmes de soutènement, la corrosion s?attaque aussi à divers installations et équipements souterrains. Cette étude, débutée en janvier 2007, est l?établissement d?une banque de données afin de caractériser les environnements miniers souterrains selon leur potentiel de corrosivité pour les systèmes de support de terrains. Pour ce faire, cinq (5) mines ont été sélectionnées afin de comparer les environnements : Laronde, Géant-Dormant, Niobec, Mouska et Doyon. À chacune des mines, trois (3) endroits ont été étudiés. Les résultats préliminaires démontrent une grande variabilité des conditions d?une mine à l?autre ainsi qu?à l?intérieur même d?une mine. La minéralogie des roches et du gisement influence la composition des eaux souterraines et la présence des sulfures joue un rôle important sur l?agressivité de l?eau et de l?air des mines de l?étude. Afin de déterminer le potentiel de corrosivité, plusieurs paramètres doivent être considérés et la mine doit être zonée selon l?agressivité des endroits.

Feb 1, 2008