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Strategic Branding ? In 2006 Explore for More was created ? By industry, for industry ? Cohesive approach to career attraction ? Defines industry and employers of choice Career Kits ? Positive impression of mining: ? before seeing the brochure 31% ? after seeing the brochure 83% ? Likely to consider a career in mining: ? before seeing the brochure 12% ? after seeing the brochure 23% MARS ? Mining Attraction, Recruitment, and Retention Strategy (2007-2010) ? Attract, recruit and retain a skilled workforce ? Increase participation of under-represented groups ? Dispel myths and misconceptions of the mining industry ? Inform and educate Canadians of career opportunities ? Promote and build upon industry best practices in workforce planning

May 1, 2009

By Chuck Edwards

"The development of two large, high-grade uranium projects has been proposed for northern Saskatchewan. The projects are now under review by a joint federal/provincial panel. The McArthur River project is owned by the McArthur River joint venture (Cameco Corporation 53.991 %, Uranerz Exploration and Mining Limited 29.775%, Cogema Resources Inc. 16.234%) and operated by Cameco. Cameco proposes to mill the McArthur River ore at the existing Key Lake mill. The Cigar Lake project is owned by the Cigar Lake joint venture (Cameco Corporation 48.75%, Cogema Resources Inc. 36.375%, Idemitsu Uranium Exploration Canada Ltd. 12.875%, Korea Electric Power Corporation 2.000%). The Cigar Lake joint venture proposes that Cameco operate the Cigar Lake mine for the owners, and that Cogema mill the ore at their McClean Lake mill, now under construction. Proposed systems provide safe mining and ore handling, and allow the milling of McArthur River ore at Key Lake and Cigar Lake ore at McClean Lake. This avoids the disturbance of new sites for milling and tailings disposal.The McArthur River and Cigar Lake deposits are the largest known high-grade uranium deposits in the world. The ore grades at McArthur River and Cigar Lake are at least 100 times those that are mined elsewhere. It is proposed to mine these deposits using remote underground mining methods, to crush and grind the ore underground, to pump a thickened ore slurry to surface, and to transport it in special containers by truck to the mills.During all mining and processing stages the ore is fully contained. Radon emission is controlled by positive ventilation of all process vessels, with the process ventilation backed up by the primary mine ventilation system. Radiation is controlled by heavy steel pipe and vessel walls, concrete walls and sometimes lead sheeting."

Jan 1, 1997

By V. Murugaiyan

The Geotechnical Engineer is faced to view problems emerging from the task of protecting the environment and also the problems related to prevention of natural hazarders. Geo-Environmental Engineering, based on the development of geotechnical engineering, addresses the problems for the industrial world and the impact on health and welfare in relation to pollution of the ground. In the recent years, acute land pollution due to indiscriminate discharge of industrial effluents especially Organic acid based effluents has become one of the major concern due to erosion in the privatization of sustainable development under Indian Scenario. To study the effect of chemical changes on soil properties due to amino acid effluent contamination on soil and erosion behavoiur. The changes in the soil properties of effluent contaminated clay and silty soil were experimentally observed to be due to the interaction of organic and inorganic constituents of effluent on index properties of soil. The surface reactivity of soil mass is experimentally reported to be varying proportionately with respect to clay (%) in the soil. Also higher surface reactivity of clay increases the Solid Retension Time (SRT) with increase in rate of chemical transformation of organic and inorganic solids within soil. Hence soil S1 (high clay content 54.5%) showed increased SRT and soil S3 (low clay content, high silt and clay content 94.9%) showed decreased SRT and long transformation stage.

May 1, 2004

By Marc C. Bétournay

Under the requirement to define the economic advantages of using hydrogen fuelcell vehicles, a broadscoped project was initiated to quantify the costs associated with operating fuelcell vehicles and diesel vehicles. While ventilation savings are clearly an advantage for the former, a complete and detailed analysis of this and other operational and capital cost elements was undertaken in order to provide the mining industry with factual information in considering the changeover from one technology to another. This article outlines the results of the investigations to date defining the costs/benefits associated with: capital purchases, operations (electrical/diesel, mine air heating fuel, ventilation, openings, surface and underground infrastructure, maintenance, labour, etc.), delivery of energy, regulatory obligations, and mine production. Considerations are given to the type and size of a mining operation, the depth, and location in North America. Significant ventilation power, equipment and infrastructure savings are possible with the application of fuelcells for shallower mine applications. At depth, where heat is an issue, there is a reduction in benefit. Specific qualifiers such as minimum air velocities, dust dilution, shaft and heating system velocity limits must be considered on an individual mine basis. While the capital cost for fuelcell mining equipment is currently higher than diesel versions, the high cost of fuelcells is anticipated to be reduced significantly in the near future with the intensification of manufacturing. In either case the operational savings would probably be sufficient to balance the supplementary capitalization costs. A comprehensive cost-benefit report will be issued in the near future.

May 1, 2003

By A. A. Beland, R. J. Dawson, S. Shewchuk

"Shovel buckets, scraper blades, dipper teeth, mine car wheels and hammermills are examples of equipment which require routine maintenance due to abrasion. Service life can be extended by the use 0/hard/acing and buildup materials. Mining and milling applications are described and field welding procedures discussed.A high-stress abrasion test used to select hard/acing and buildup materials/or hammers in a hammermill is described in detail. Field tests of the selected alloys confirmed their performance, and maintenance records showed a significant saving in down time and cost.The relationship between the abrasion resistance of the alloys and their hardness, work hardening, composition and microstructure is summarized. IntroductionLarge volumes of ore are handled daily by the mining industry. The abrasive nature of most ores results in extensive wear to both handling and processing equipment. If such wear is neglected it may cause lost production time and also, in extreme cases, require the complete replacement of expensive equipment. The well-planned maintenance of components subject to abrasive wear by means of buildup materials and hard facing can result in substantial economic benefits. Such benefits can , however, only be realized through the correct choice of welding process, consumables and deposition methods available to maintenance personnel. Hardfacing MethodsHardfacing is applied by a variety of methods; the three most widely used being arc welding, oxyfuel gas and thermal spraying. Table 1 summarizes the major processes used within each method. Filler metals in the form of rod, wire or powder are necessary to fulfill the individual requirements of each process. The filler rods are available in the cast form or, in the case of ductile metals or alloys, as wrought rod or tube. All types are supplied bare or flux covered. Wire is supplied in two forms, drawn flux cored and drawn solid. Powder filler metals are available in many metals or alloys; they may be simple mechanical mixtures or prefused and atomized alloys made to a specific size range and shape for optimum results for each applicable process."

Jan 1, 1980

By A. C. Wilson

In 1991, local prospector C. ?Mickey? Clement recovered at least three alluvial diamonds from the Michipicoten River. Two of these stones were sent to the Department of Mineralogy, Royal Ontario Museum, where they were identified as industrial grade diamonds with weights of 1.05 and 1.13 carats. Both stones were described as frosted and graphite-inclusion riddled. In 1995, prospector Sandor Surmacz and geologist Marcelle Hauseux discovered diamonds in bedrock approximately 20 km north of the Michipicoten River. An 18.1-kg bulk sample of a xenolith-rich lamprophyre, taken from an outcrop at the side of the Trans Canada Highway north of Wawa, yielded 1 macro diamond and 5 micro diamonds. All but one was gem quality (Sage 2000). Since then, more than 36 occurrences of diamonds in bedrock have been reported in an approximately 30 km2 area centred 20 km north of the town of Wawa. The occurrences are hosted within a sequence of unusual, Archean-aged, heterolithic breccias previously considered to have no economic significance. Ten kimberlite occurrences also have been confirmed in the Michipicoten greenstone belt in the last 5 years. Two of these kimberlites are diamondiferous. To date, expenditures on property acquisition and diamond exploration in the Wawa are estimated at $120 million (CAN). This paper summarizes the geological observations made on these occurrences and discusses including the relationship between the occurrences and the regional geology.

May 1, 2003

By Karim El-Ouassiti, Marc Minville, Stéphane Chabot, Claude Bazin, Valérie Ouellet

"Alumina is the main source of aluminium and it is extracted almost exclusively from bauxite ores found in the Southern hemisphere. Clays are abundant minerals that contain from 15 to 40% w/w of alumina from which it can be extracted by various processes. This paper reviews the processes used for the extraction of alumina from clays and discusses results obtained with a clay sample from the Murdochville area in the Quebec Province. The application of a conventional process to this clay did not yield an acceptable recovery although smelter grade alumina was produced. A modification to the process allows increasing alumina recovery from 85% to more than 92%. The application of the improved flow sheet to other alumina carriers failed to yield comparable recovery, showing that an optimum processing path for the recovery of alumina should be found for individual clay materials.INTRODUCTIONMost of the aluminium smelters are fed with alumina extracted from bauxite found in the Southern hemisphere. Bauxite is processed by the Bayer process that uses a caustic leach of the ore. In the middle of the century, the US Bureau of mines, motivated by the fear of an alumina delivery disruption, conducted several research projects aiming at producing alumina from non bauxitic ores. These projects led to the development of various acid leaching processes (Habashi, 1993). The sulphuric and hydrochloric acid leaching processes were brought to pilot plant evaluation (Bengtson, 1979), while nitric and other leach liquors were tested in the laboratory (Phillips and Wills, 1982; Habashi, 1983). Although clays are abundant and inexpensive minerals, the studied processes remained uncompetitive with the alumina extraction from bauxite (Hudson, 1987 page 42; Peters et al., 1962) for which reserves are estimated to support alumina production for the next 50 years (Oye et al., 1999). On the other hand, the local extraction of alumina from clays could significantly reduce the transportation costs of alumina to smelters and provide an alternative source of alumina supply from the Southern hemisphere countries. Also, the extraction of secondary products for some types of clay (Nasyrov et al., 1999) containing significant amounts of potassium and sodium could provide an additional return that may improve the economics of alumina production from clays."

Jan 1, 2005

By H. A. Steane

"This presentation will cover some crushing and grinding considerations in plant design and operation. There is nothing basically new in the subject matter presented here; however, the viewpoint and interpretation may be novel and some of it controversial.The presentation is based on experience gained in the metallurgical design of plants for Placer Development Limited from 1960 to the present. The plants are listed on SLIDE No. 1.These plants have conventional crushing, followed by rod mill and ball mill grinding. I would like to think that autogenous grinding plants are the answer for eliminating secondary crushing plants and reducing the capital and operating costs; however, the autogenous plants seem to have some problems of their own and I have had no experience with them.Fineness of Grinding RequiredFirst let us consider the fineness of grinding required.The fineness of grind will affect the recovery obtained, and the relationship must be determined. If the grinding is too coarse, some of the valuable mineral, either free or locked in middling grains, will not be floated. However, as grinding is probably the greatest single operating cost, we do not want to grind any finer than is justified economically.Finer grinding should not be carried beyond the point where the net smelter return for the increment saved becomes less than the added operating cost. Even this fineness will be beyond the economic limit because of the additional capital cost for the equipment needed to achieve it. These factors will be discussed in more detail later.The Bond work index is the commonest method of expressing a measure of the effort that has to be expended in grinding. It is the kilowatt-hours required to reduce a ton of rock from an infinite size to 80% passing 100 microns. The formula allows a calculation to be made for other size ranges."

Jan 1, 1976

By B. K. Gorain, A. W. Stradling

"The traditional metallurgical scale-up techniques for flotation plants are based on lumped flotation rate constants, dimensionless hydrodynamic numbers and the use of safety factors. Once the plant has been designed, the flotation principles that govern scale-up play almost no role in the optimization of the circuit to meet its metallurgical targets. This deficiency can potentially lead to a plant design incapable of meeting its targets, especially when circuits incorporate large flotation cells. This paper demonstrates the application of the k = PSbRf model in providing a suitable framework for flotation modelling, scale-up and circuit optimization, thus presenting an integrated approach to the problem. Studies were conducted at Teck Cominco’s Red Dog concentrator to characterize cell hydrodynamics, gas dispersion properties, froth flow behaviour, entrainment and ore floatability to obtain the key data necessary to develop a model for the flotation circuit. The findings of these studies are presented in this paper, which provide valuable insights into the modelling and optimization of the Red Dog flotation circuit. IntroductionThe traditional methodology for flotation scale-up and plant design is based on the ruleof- thumb with safety factors and dimensionless hydrodynamic group similitude considerations. With the recent trend toward larger flotation cells with volumes of 150 m3 and greater in concentrators, the problem of scale-up has become even more acute. The scale-up factors that may have been tolerated on smaller cells are not applicable to larger cells. The transportation of froth in these large cells adds further complexity to the problem. Arbiter et al. (1980) foresaw this problem and pointed out that if scale-up were attempted by rule-ofthumb and trial-and-error, the probability of failure would then increase with scale. This problem is confounded by the fact that the design and scale-up considerations used for a new flotation circuit play almost no role in optimization of the circuit to meet its metallurgical target. This results in a plant design, which may be incapable of meeting its metallurgical targets. There have been several instances where new concentrators have required significant circuit modifications and additional capacity to achieve design targets."

Jan 1, 2003

By Bruno Bussière

Le drainage minier acide (DMA) provenant de la circulation des eaux à travers les rejets miniers sulfureux est sans doute le principal problème environnemental auquel est confrontée l?industrie minière. Afin de prévenir les problèmes environnementaux reliés au DMA, on doit restreindre la présence de l?une et/ou de l?autre des principales composantes menant à la production d?acide, soit l?eau, l?air et les sulfures. Pour ce faire, différentes techniques ont été proposées au cours des dernières années, dont la désulfuration environnementale et les couvertures avec effets de barrière capillaire (CEBC). Dans ce papier, on propose d?utiliser ces deux techniques en combinaison. Ainsi, on produirait un rejet désulfuré à l?usine de traitement qui pourrait, par la suite, être utilisé comme matériau pour la couche de rétention d?eau de la CEBC. Dans un premier temps, on présente les résultats d?une étude de laboratoire qui montre qu?il est possible de désulfurer les rejets de concentrateur à l?aide de la flottation non sélective jusqu?à l?obtention d?un résidu non générateur d?acide. Par la suite, des essais en colonne ont permis de démontrer qu?il est possible de limiter la production de DMA d?un résidu sulfureux à l?aide d?une CEBC dont la couche fine est constituée de résidus désulfurés. Des prédictions théoriques estiment même que la présence de sulfures résiduels dans la fraction désulfurée utilisée comme matériau pour la rétention d?eau peut avoir un effet bénéfique en réduisant la migration d?oxygène. En effet, les sulfures contenus dans la couche de rétention d?eau peuvent consommer l?oxygène qui tente de migrer vers le bas et, ainsi, réduire les flux d?oxygène qui atteignent les rejets réactifs.

Nov 1, 2002

By Patrick Frenette

Résumé La Mine Goldex entrera en production au 2ième trimestre de 2008. Pour permettre une production de l?ordre de 6960 tpj, le forage ITH à une pression de 400 psi (28 bar) à été sélectionné. Il s?agira d?une des premières applications du forage ITH à cette pression sous terre. Cet article traitera des gains anticipés et montrera certains résultats préliminaires. Il sera aussi question du bras manipulateur utilisé pour manipuler les tiges de forage. Abstract The Goldex Mine will start production in the second quarter of 2008. In order to achieve a production of 6960 tpd, ITH drilling at 400 psi (28 bar) was selected. ITH drilling at this pressure will be one of the first underground applications. This paper will discuss the anticipated gains and show some preliminary results. The use of the rod handler will also be discussed.

Feb 1, 2008

By Philip A. Dirige

This paper presents the variability of responses of paste backfill specimens that have been prepared with varying binding agent and binder combinations, when subjected to uniaxial compressive strength testing. A testing program conducted for an underground operating mine to produce cost efficient paste fill recipes using four different binding agents, in various ratios and combinations, is presented to illustrate the responses. These binding agents are Normal Portland Cement Type-10 (NPC T-10), oxidation or sulphide attack resistant binder (Binder A), replacement binder B (Binder B), and replacement binder C (Binder C). The paste fill recipes were prepared at 2, 3.5 and 5% binder content at varying binder combinations, at fixed size and tested in a Material Testing System (MTS) under constant strain rate conditions following cure times of 7, 14, 28, 56, 90, 112, 180 and 240 days. The results of tests suggested that the strength data clearly shows a trend of increasing strength with increasing binder content but not necessarily cure time. It is noted that all the blends achieved dramatic increases in strength up to 28 days of cure and then either increased or decreased moderately beyond 28 days curing, depending on the binder content and binder combination. The moderate decrease is apparent for the 2% paste fill blends and in some binder combinations of the 3.5 and 5% blends, which indicated lackluster performance beyond 28 days curing. This lackluster strength performance indicated that the binder content and combination may not be sufficient for the paste fill to achieve complete hydration and acquire adequate strength performance beyond 28 days. This study indicated that economic paste fill recipes can be designed with confidence using affordable alternative binders. However, it is noted that these alternate binders cannot be used as stand alone binders but should be used in combination with NPC to facilitate hydration of the paste fill.

May 1, 2006

By Brad E. Melanson

Because mine haul trucks consume considerable quantities of fuel, they are ideal candidates for the adoption of cleaner and cheaper fuels like natural gas. Impressive fuel cost savings will be realized in regions where liquefied natural gas (LNG) has cost advantage to diesel fuel, while also providing significant reductions of air contaminants and greenhouse gases. High Pressure Direct Injection (HPDI) of natural gas utilizes the diesel cycle combustion process and therefore retains the diesel engine?s high performance and efficiency characteristics. HPDI has been demonstrated in on-road Class 8 trucks since 2001 accumulating almost 10 million kilometres to date. The supply of LNG fuel will be an essential parallel aspect in the introduction of HPDI to mining. LNG can be transported to site as diesel is today, or may be produced on or near mine operations that have access to methane sources or pipelines.

May 1, 2006

By R. E. de Barrio, M. E. Lanfranchini, R. O. Etcheverry

"The El Abuelo Ca-Fe-magnetite skarn and related hydrothermal quartz veins are located at Cerro Pepita Hill, in southwestern Chubut province of southern Argentina, 1700 km southwest of Buenos Aires. These deposits are developed in a continental magmatic arc environment linked to the Andean orogeny. Iron skarn mineralization is mainly hosted by an Upper Jurassic to Early Cretaceous sedimentary sequence interbedded with Upper Jurassic basaltic andesite, and is spatially associated with Early Cretaceous calc-alkaline dikes. Ore grades vary between 40 and 63 wt.% Fe. In addition, anomalous metal contents (>10 000 ppm Cu and up to 81 g/t Ag) are present in the hydrothermal quartz veins.At least three paragenetic mineral assemblages have been identified in the El Abuelo exoskarn: (1) amphibole > epidote ± chlorite ± quartz, formed by isochemical contact metamorphism; (2) Fe-clinopyroxene ± Ca-garnet, formed during prograde metasomatic anhydrous exoskarn formation; and (3) actinolite ± epidote ± chlorite ± quartz ± magnetite > titanite, resulting from hydrous retrograde alteration of exoskarn. Endoskarn alteration involved an early Mg-Fe-clinopyroxene ± Fe-garnet assemblage followed by retrograde actinolite replacement of pyroxene. Lower temperature hydrothermal alteration related to quartz veins was superimposed on the skarn assemblages, showing an innermost sericite ± adularia ± pyrite ± chalcopyrite assemblage and an external propylitic halo.Some metallogenic characteristics of the mineralization and the geological setting resemble those in several iron oxide copper-gold deposits elsewhere in the world."

Jan 1, 2007

By Derek J. Cyr

Climate has an immense impact on the properties of Athabasca oil sands and the ease or difficulty with which it is excavated and extracted. During the winter months, exposed oil sands surfaces freeze. When hydraulic and electric shovels used in the various operations in the Fort McMurray area excavate the benches, large frozen lumps are created. These lumps are either destined for a lump dump where increased costs are incurred due to rehandle, or they are sent to the primary crushers where they can cause significant downtimes by jamming the crusher. The crusher down time can sometimes be in the order of hours of lost production. Studies on data from two consecutive winters at Syncrude Canada?s North Mine show a high correlation between climate and the generation of frozen oil sands lumps. Temperature, ground cover, traffic, bench exposure time, oil sands grade and moisture content all contribute to this problem. A 1D frost penetration model was used to predict the depth of frost expected in oil sands and the corresponding likelihood of frozen oil sands lumps. To combat the challenge of frozen lump generation, a number of proactive and reactive measures can be taken: artificial snow, shallow ponds, scheduling, blasting or ripping.

May 1, 2004

"This paper describes some of the methods and equipment used for fine milling of minerals, and gives particular attention to the Vibro Energy system.In addition, the paper describes a specific application in the gold mining industry. This is the 200 tpd plant built by Anglo American Corporation at the President Brand Mine in South Africa in 1985, now a division of Freegold. This plant treats a gold bearing pyrite flotation concentrate which is finely ground to 15 microns prior to cyanidation and carbon-in-pulp (CIP). l .0 INTRODUCTIONFree milling gold ores are those that yield acceptable dissolution and recovery of the gold following grinding to what can be described as normal fineness, frequently between 50% and 90% passing 74 microns.Increasingly, gold metallurgists are faced with ores that are refractory. The traditiona1 treatment route for refractory gal d ores and concentrates has been by roasting, but for environmental reasons this is becoming less acceptable, or in some areas of the world, totally unacceptable. New methods of treating refractory gold ores are being developed and applied in practice. These new methods include pressure and biological oxidation. Higher gold liberation can also be attained by increasing the fineness of grind, although with conventional systems there are economic limits to this.In flowsheet development and test programs on new deposits, a standard procedure is to establish the relationship between the grind and subsequent go 1 d extraction. The normal situation is that gold extraction increases as the ore, or concentrate, is ground finer. Typically, this relationship is as shown in Fig. l, where the incremental additional extraction is very small once an optimum, or economic, grind has been achieved. This generally app1ies whether the material is free milling or refractory. The limits to grinding are set by the type of equipment which is commonly in use, usually ball mills. These mills have the obvious advantage of high capacity, however, they are increasingly inefficient as finer grinds are required. In general, ball mills are used to reduce ore to some agreed percentage passing 74, or possibly 53 microns."

Jan 1, 1988

By Jean-François Lapointe

Many advances have been made concerning the automation of heavy equipment teleoperators such as those found in mining. Complete automation, however, is not achieved yet and the operation of these vehicles still relies on the presence of a human operator. Fortunately, a lot of research has been done in order to improve the performance of these human-machine systems. This paper presents the characteristics of different control modes and input devices used for the control interface of those telemanipulators. We describe the benefits and drawbacks of each particular control interface on the overall system performance, based on a review of research in the field. We conclude with some recommendations and a discussion of future research needs, given the new potential advances offered by virtual environment technology and embedded computing.

May 1, 2001

By Elizabeth Gardiner

Tailings and water management facilities are integral components of mine and mill operations. They must be managed for the long term to ensure that safe and environmentally responsible stewardship is achieved. The Mining Association of Canada (MAC) has developed and published two manuals to provide guidance to mining companies on sound practices for the safe and environmentally responsible management of tailings facilities: ???A Guide to the Management of Tailings Facilities; and ???Developing an Operation, Maintenance and Surveillance Manual for Tailings and Water Management Facilities. The Guides were designed to help companies develop and implement tailings management systems that include environmental and safety criteria, to improve the consistency of application of sound engineering and management principles to tailings and water management facilities through their full life cycle, and to demonstrate this to regulators and the public.

May 1, 2003

By Emilie S. Williams

The Doyon Mine?s Zone 1 (Altered Zone), found along the southern boundary of the mine, encompasses approximately 20% of the mining reserves. The mineralisation is found in a series of steeply dipping narrow veinlets, which are contained in an extremely weak host rock: a sericitic schist with RQD values ranging from 0 to 20. Longhole mining methods are used, with either longitudinal or transverse approaches, depending on the width of the ore zone. Dilution is of critical importance in the mining of this zone, particularly in longitudinal stopes, where dilution levels have averaged 55% since 2000. Major factors influencing dilution in this zone include the stope geometry and standup time. A two-phase approach has been developed to mine and backfill longitudinal stopes: the top of the stope is pastefilled after approximately half of the broken ore has been extracted; the remainder of the ore is extracted once the plug has cured; and the remaining void is filled. This method has been used in six stopes to date, resulting in an average dilution of 17%. This paper details the application of this technique and its effect on dilution.

Oct 1, 2004

By E. M. Watkin

"Land directly disturbed by hard rock mining activities in Ontario and Quebec was surveyed in 1974 as part of a country-wide assessment, (Murray 1977). Some 15, 000 hectares, or 5 7 square miles, are listed as having been disturbed by overburden removal, waste rock and tailings deposition (Table 1) in the region. That area represents sixty-eight per cent of the total area which ha1; been disturbed by mining in central and Atlantic Canada. Assessment of disturbed areas was undertaken using LANDSAT-1 and LANDSAT-2 satellite imagery. Certain limitations of the technique were recognized but the data obtained were considered a relatively acceptable assessment of the extent of disturbed areas larger than ten hectares.Approximately ten per cent of the land disturbed by mining in the two provinces has been reclaimed to varying degrees. Indeed, this proportion is correct for the country as a whole. As pointed out by Ripley, Redmann and Maxwell (1978), some of the land was disturbed long before environmental concern 01· reclamation were ever considered. In numerous instances reclamation will remain impossible until presently active operations are closed. Nevertheless, these authors feel such figures make it clear that reclamation has not been a high priority in Canada in the past. Canada is a vast country, and there has been little pressure toward efficient use of all land space. Most mining operations occur in areas distant from the country's population centres. Under these circumstances, therefore, the pressure to reduce the environmental impact of mining is much less than in the more densely populated areas of Europe and the eastern United States, where such activity can occur in or adjacent to large metropolitan areas."

Jan 1, 1980