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By Aleksandar N. Nikoloski, Tendekayi Tapera, Glen P. O’Malley

Chalcopyrite (CuFeS2) and enargite (Cu3AsS4) are among the most important copper sulfides. At present, many known deposits of these minerals are uneconomic to process because they are of too low grade, insufficient size or too remote to be cost effectively treated with conventional technologies that can deal with their refractory nature. Therefore, developing an effective, low cost extraction process for recovery of copper from them is important. The research presented in this paper will deal with potentially cost effective strategies involving catalysed processing, studied under conditions relevant to recycle heap leach conditions. The present account summarises some of the main findings from the research program carried out at Murdoch University between 2014 and 2018 that has investigated the effects of the common leaching parameters, major and minor species present in the leach system and additives on the rate and extent of copper extraction from low-grade ores, in which primary copper sulfide minerals such as chalcopyrite and enargite were the dominant copper minerals. The study involved batch leaching tests, detailed structural and mineralogical characterisation and thermochemical modelling under conditions relevant to heap leaching. The results have demonstrated that silver in particular has a strong catalysing effect on the extraction of copper from ore under the leach recycle conditions and, at an adequate dosage, can effectively overcome surface passivation, enabling almost complete extraction of copper from chalcopyrite as well as enargite. The aim of this paper is to present the effect of the studied additives and to briefly elaborate on the mechanism of the silver catalysed leaching process. In addition, the presence of certain secondary agents was shown to lower the critical dosage of silver and promote extraction. The data from the study allowed the development of a theory for the silver catalysed reaction mechanism, which enables further optimisation and cost-effective application of this strategy in practice. INTRODUCTION Researching the extraction of copper from chalcopyrite is important as it is the most abundant copper mineral in the earth’s crust. The majority of ores containing this mineral are processed by flotation to produce a concentrate, followed by smelting and electrorefining. However, most reserves available nowadays are of low grade or limited in size, and therefore not suitable for this conventional approach. Hydrometallurgical processing via heap leaching with or without the aid of bacteria has been shown to be potentially economical. Chalcopyrite is refractory though and suffers from slow leaching kinetics and poor overall extraction, so understanding the mechanism of how it leaches has received significant attention by researchers working in this field over the past 50 years. The refractoriness, which is the main issue with the hydrometallurgical approach, is generally described as passivation of the chalcopyrite surface whereby a surface coating is formed that blocks the reaction interface or wetting of the chalcopyrite, limiting the copper extraction. Exactly what this layer is made of or how the issue could be overcome has been the subject of intense study and debate for many years. One of the limitations of the work to date is that much of the research focus has been on typical initial leaching conditions, while there has been relatively little research into how the leaching is affected under recycle solution conditions where certain metal ions (Fe, Mg, Al) have often accumulated in the liquor. This occurs because the leach solution exiting a heap contains many species from the dissolution of gangue minerals and typically this solution is returned to irrigate the heap, once the copper has been removed, leading to an accumulation of these species.

Jan 1, 2019

"The Schist Lake mine, owned and operated by the Hudson Bay Mining and Smelting Co., Limited, is situated on the northwest arm of Schist Lake, 4 miles southeast of Flin Flon, Manitoba.The deposit was discovered early in 1947, during a diamond drilling program exploring small copper showings along the west shore of the lake. The orebodies came to surface between the mainland and the north end of Stitt Island.Production began in August, 1954, at an initial rate of 300 tons per day. Underground workings have been carried to the 1,700-foot level, where exploration work is now being done.General GeologyRocks of the area are Precambrian lava flows, with associated pyroclastic breccias and tuffs, and related minor intrusions. Their general strike is northwest and their dip is nearly vertical. Shearing is common and is related to the activity which caused intense folding and much faulting in the area. The larger faults and the fold axes trend a few degrees west of north. The lavas are mainly andesitic but a layer of sericite-carbonate schist, which is probably derived from a fine-grained, grey quartz porphyry, occupies most of Stitt Island and extends into the mine area. It is within this layer of schist that the ore deposit occurs (Figure 1).The OrebodiesThe ore occurs as tabular to lens-shaped bodies which strike northwest, dip nearly vertically, and plunge at 60 degrees to the southeast. The ore zone is 800 feet long and has been traced for a distance of 2,000 feet along the plunge (Figure 2). The maximum length of continuous ore within this zone is 200 feet. Widths of individual ore lenses vary from a maximum of 35 feet to a minimum of 2 feet.The ore consists of three distinct types: massive sphalerite-pyrite, massive chalcopyrite-sphalerite, and disseminated chalcopyrite-pyrite. The No. 1, or eastern, orebody is predominantly massive sphalerite-pyrite. The western part of the No. 2 orebody is massive chalcopyrite-sphalerite. The disseminated ore forms the eastern part and the lower end of the No. 2 orebody. All three types of ore, with patchy distribution, are found in the smaller lenses below the 1, 100-foot level.Metallic minerals, in order of deposition, are pyrite, arsenopyrite, chalcopyrite and sphalerite, galena, enargite, and gold. Both massive types of ore exhibit banding in many places, probably as a result of the selective replacement of schist. The disseminated ore was formed as a filling of the interstices in a brittle chert rock which appears to have been crushed by the same forces which produced the schist."

Jan 1, 1949

By A. F. Robertson

FOR several years, the rock-burst question has been given serious consideration by the operating staff at Wright-Hargreaves mine and, as a result of observations and experiences, several different methods of mining have been developed which are now in use in various parts of the mine. These are described in the following pages. It should be emphasized, how-ever, that these methods, and the views expressed in this paper, are based solely on conditions at Wright-Hargreaves mine. Such conditions may or may not be similar to those obtaining in other mines in the Kirkland Lake area, where ore occurrences, veins, wall-rock, faulting, intrusives, etc., may be entirely different. Size and shape of ore-bodies, composition of the ore-bodies and their surrounding rocks, locations of intrusives and sedimentary rocks, and direction, dip, and strength of faults, all introduce problems that are peculiar to each individual mine. Ground failure' in coal and metal mines is not at all unusual. A variety of systems of mining have been developed to delay movement of large or small blocks of ground, or, in some instances, to take advantage of the fact that ground movement, due to mining operations, is unavoidable. Ground failure may be either slow collapse or it may take place with explosive violence. It is principally with the latter condition that we are concerned in the mines of the Kirkland Lake district.

Jan 1, 1939

By J. H. Douglas, A. F. Matheson

"The Hard Rock is the most easterly producing mine in the Little Long Lac area. The Company was formed in 1934 to develop a surface showing of gold in quartz made by a prospector, W. W. Smith, in 1931. Although some ore was eventually produced from this discovery, the principal orebody, hidden below 10 feet of muskeg, was found about 1,000 feet to the north by exploratory diamond drilling early in 1938 from the No. 2 shaft workings at the 250-foot level.Production started in 1938 and to January 1, 1947, 201,000 oz. gold had been obtained from 1,165,282 tons of ore mined and 869,397 tons milled. Of this ore about 15 per cent came from the development and mining of the original orebodies discovered at the surface. The remainder came from the ore found by the underground diamond drilling done in 1938. Of the latter ore, the Company estimated, at January 1st, 1947, only 140,000 tons remained. The orebody, therefore, contained approximately 1,100,000 tons.OREBODIES AND GENERAL GEOLOGYThe orebodies of the Hard Rock mine are of two main types: the quartz ore of the south and No. 1 shaft zones, and the sulphide ore of the north zone. The quartz ore consists of white quartz veins mineralized with sparse, fine, light-coloured pyrite, or, less commonly, nests of coarse, crystalline, light pyrite. A little tourmaline, scheelite, pyrrhotite, chalcopyrite, arsenopyrite, and native gold are also present. Native gold occurs in a few places in quartz veins in exceedingly rich cemcentrations, apparently where there are large, light-coloured, pyrite crystals of imperfect form. The ore of the north zone is massive pyrite with arsenopyrite and in places pyrrhotite. Many short irregular quartz veins, from a few inches to 2 feet in width, are also present, but the quartz forms a very small percentage of the whole. The veins may be flat to vertical, and sulphides on one or both sides replace the host rocks. The gold is closely associated with the sulphides . The quartz is commonly barren except where it contains sulphides or along the borders of the sulphide ore zone where native gold is not uncommon in quartz stringers."

Jan 1, 1954

By Robert D. Brown

"Important tax changes, many of them of direct interest to the mining industry, were contained in the budgets brought down by federal and provincial finance ministers across Canada this spring. This month, Tax Notes presents a brief summary of important tax changes introduced at the federal and provincial levels in the last few months.IntroductionIn the March 1980 issue of the CIM Bulletin, Tax Notes surmised that the short-lived 1979 budget proposals of the former Conservative government offered a unique glimpse of budgetary changes that might be unfolded in 1980. Scene II of this ""now you see it-now you don't"" drama opened on April 21, 1980, when Finance Minister Allen MacEachen, in an ""economic statement""' reintroduced a selection of tax proposals taken from the ill-fated Conservative' budget of December 11, 1979, but refused to bring forward major new proposals in tax and finance.Mr. MacEachen proposed a 5% surtax on federal corporation income tax to apply in the 2 years from January 1, 1980 to December 31, 1981, as a slightly modified version of the same surtax proposed by former Finance Minister Crosbie in his December budget address. Mr. MacEachen also reintroduced a number of technical amendments which would affect the taxation of mining income in certain instances. In addition, a large number of other tax proposals suggested in the previous Conservative budget were also reintroduced, although there are some notable omissions."

Jan 1, 1980

By David W. Smith

"This paper is devoted mainly to a discussion of the hydrocarbon potential of the offshore, with a few brief remarks concerning the inorganic mineral potential.OFFSHORE OIL AND GAS POTENTIALIN ORDER TO HAVE HYDROCARBON ACCUMULATIONS, we must satisfy three basic requirements. First, we re-quire a sufficient thickness of sedimentary rocks which contain some porous and permeable formations to act as reservoirs. Second, we require some type of trapping mechanism, such as faulting, folding or stratigraphie trapping. Finally, we require that large quantities of hydrocarbons have been generated within the sedimentary rocks and have migrated to the traps."

Jan 1, 1969

By Mark W. Masson, David B. Stevenson, David W. Broughton, Douglas R. Cruji, Steven E. Parry

"Abstract-The Amalgamated Kirkland gold deposit is located at Kirkland Lake, Ontario, within the Archean Abitibi Greenstone belt of the Canadian Shield. It lies on a fault or "break", termed the Cyprus Break, which is a splay off a regional structure termed the Cyprus-Battle Mountain Break. The Cyprus Break merges with the Cyprus - Battle Mountain Break above the -250 m level, as it was not encountered in shallow drilling or surface exploration. These structures lie 1.5 km south of the 727 000 kg (23 million ounce) Kirkland Lake Main Break and 0.5 km north of the 872 000 kg (30 million ounce) Larder Lake Break.The deposit is hosted by alkalic Timiskaming Group volcanic and sedimentary rocks which are overthrust by older Larder Lake Group tholeiitic and komatiitic flows along the Larder Lake Break. Timiskaming syenitic intrusives, similar to the host rocks for the Kirkland Lake Main Break gold deposit, intrude both suites.The Amalgamated Kirkland deposit consists of lode-style gold mineralization which is mainly hosted by altered and pyritized Timiskaming trachytic volcanics which wedge out or thin at depth, between two sedimentary units. The intersection of the Cyprus - Battle Mountain and Cyprus Breaks, in conjunction with the westward plunge of the volcanic wedge, appears to control the westerly plunge of the Amalgamated Kirkland deposit at approximately 50º.Mineralization is characterized by blue-gray brecciated and "wormy" quartz-ankerite veins which contain up to 10% fine-grained pyrite and, in decreasing order of abundance, minor galena, chalcopyrite, sphalerite, molybdenite and visible gold. The sulfides and gold commonly occur along fractures and wallrock inclusions within the veins. Native gold occurs as fine pinpoints distributed in 1-mm to 5-mm size clusters of up to ten or more grains.The auriferous veins occur within a quartz-ankerite-sericite-pyrite alteration assemblage which is enveloped by a broader zone of ankerite-sericite±hematite±quartz-pyrite alteration up to 60 m wide. This latter assemblage overprints the regional greenschist-facies chlorite-calcite assemblage.The Amalgamated Kirkland property has had a long history of exploration activity beginning with the first discovery of mineralization in 1911 on the Hunton Shaft claim located in the northeast corner of the property. Since that time various prospecting, mapping, trenching, geophysical surveys and diamond drilling programs have concentrated on either carbonate zones along the Larder Lake Break or quartz veins along the northern side of the property in association with complex trachyte flows and syenite dikes.Battle Mountain Canada Inc. located the Cyprus - Battle Mountain Break through a prospecting, trenching and geophysical program in 1989. Drilling by Battle Mountain and Cyprus Canada under the surface showing, coupled with several revisions to the structural interpretation of the Cyprus - Battle Mountain and Cyprus Breaks, resulted in delineation of the Amalgamated Kirkland deposit. Location of an auriferous structure through basic surface exploration within 1 km of a world-class orebody demonstrates both the subtle nature of Archean gold deposits and the potential for finding new mineralization in heavily prospected camps."

Jan 1, 1995

By Jeremy P. Richards

Key inputs are volatiles and heat: Slab dehydration: Breakdown of amphibole and serpentine in hydrated oceanic crust releases fluids into mantle wedge, causing metasomatism.

May 1, 2008

NANA Accepts Mining ­ 1974 - Leadership presented mining option to people ­ Community meetings; recognized need for cash economy ­ 1979 - Poll shows consensus in favor of mine development ­ 1980 - Shareholders approve mining; Congress approved land selections

May 1, 2002

By R. S. Jr. Stronach

"IntroductionThe property of Campbell Red Lake Mines, Limited, is in Balmer township, Red Lake area, Patricia portion of Kenora district, Ontario. It consists of a group of twelve claims which had been staked and re-staked a number of times before George W. and Colin A. Campbell staked them in 1944. Messrs. Brewis and White incorporated Campbell Red Lake Mines, Limited, in July, 1944, to acquire these claims from the Campbell brothers, and in November of the same year re-assigned their option on the controlling interest of the treasury shares to the Dome Exploration Company (Quebec), Limited, a wholly owned subsidiary of Dome Mines, Limited.A long known exposure of sulphides on the northeasterly portion of the property, which returned low gold assays, on sampling, was the only showing of interest at this time. However, Dr. H. C. Horwood's report and map of the district had recently been published and favourable structure W3.S indicated in Balmer township. It was on the strength of this showing and Dr. Horwood's report that Dome Exploration became interested in the property.Between. January, 1945, and April, 1946, a diamond drilling programme was carried out, with completion of sixty-one holes. Five holes proved the surface showing to hold no commercial interest, so routine cross-sectioning of the property from north to south was started. The fourth hole of the series returned excellent ore intersections and from that time on the programme changed to one of extending these values. The final results of the drilling showed that what is now known as the A zone has a continuous length of some 1,200 feet, a width of 4½ feet, and an overall grade of about 0.5 oz. gold per ton. There were many other intersections of ore grade outside this A zone which could not be successfully correlated .at that time, but underground work has opened many of them. It may be said here that practically all the work to date has been confined to the southeast claims of the property."

Jan 1, 1950

By Bert Taylor

"The Mining concessions of Quemont Mining Corporation, Limited, are located at 48°16'N latitude, 79°00'W longitude, in Rouyn township, northwestern Quebec. Six hundred and forty acres in area, they lie directly north of, and contiguous to, the Horne mine of Noranda Mines Limited. The north arm of Osisko Lake covers a large area of the southern part of the property. The orebodies lie below the Jake with one body extending through to the bedrock surface.The property was staked in 1922, and was originally known as the Murray Claims. The group attracted interest from numerous exploration companies because of the proximity of the Noranda orebodies.The United Verde Extension Company, of Arizona, optioned the claims in 1926. They sank a shaft to a depth of 235 feet, at a short distance from the Noranda boundary. From a level established at a depth of 215 feet they completed 3000 feet of exploratory driving from which 6000 feet of diamond drilling was done. Only a small body of siliceous gold ore was found before they dropped their ·option.In 1928, The Mining Corporation of Canada purchased a 90 per cent interest in the property. An operating company, later named Quemont Mining Corporation, was formed. An electrical survey was carried out on a portion of the property, followed by deepening of the shaft to 922 feet. Levels were established at 500 and 900 feet, and 4,800 feet of driving and more than 3000 feet of diamond drilling were carried out from them.Geological knowledge at that time recognized that a major break, the Horne Creek fault, lay not far inside the south boundary. Striking north 80 degrees east, the fault dipped south at 85 degrees. The rock on the north side of the fault was massive rhyolite; to the south, meta-diabase and a little rhyolite. A left-handed movement was indicated by a 600-foot offset on a north striking diabase dyke. The small body of siliceous gold ore, referred to previously, was confined to the 215 level."

Jan 1, 1949

By W. W. Weber

"The Mine property comprises some 700 acres in ranges VI and VII, Barraute township, about thirty-seven miles due north of Val d'Or in northwestern Quebec.The transformation of a small farming community into the youngest and largest zinc producer in eastern Canada began late in the autumn of 1950. At this time, a geological survey party of the Quebec Department of Mines discovered sphalerite-pyrite mineralization in a strong regional shear structure crossing range VII of Barraute township. Diamond drilling commenced in November 1950, and by June 1951 a total of more than 63,000 feet of drilling, at fifty-foot intervals, had explored an ore zone 2,500 feet in length and 102 feet in average width to a depth of 700 feet, the deepest ore intersection.Production started late in 1952, and is at present in excess of 4,000 tons per day. Production in 1954 of77,790, 166 lbs. of zinc and 989,610 oz. of silver, from 1,525,284 tons of ore, makes this mine the largest zinc producer in eastern Canada.General GeologyAll the consolidated rocks of the area are Precambrian, and most of them are volcanic. They consist mainly of subsiliceous Javas, with smaller amounts of siliceous to intermediate lavas and pyroclastic rocks. The lavas have been intruded contemporaneously by many sill-like bodies of coarser-grained diorite and gabbro. There are no sedimentary rocks within ten miles of the mine.A period of major folding and faulting was followed by intrusion of granite. The volcanic rocks have been compressed into isoclinal folds trending roughly east-west, and the granitic batholiths also show a rude lineal alignment in the same direction. The granitic masses vary consider-ably in composition, ranging from the potassic LaCorne granite, ten miles south of the mine, to the sodic Duverny mass, ten miles west. In addition there is a variation from a general granitic core to dioritic and gabbroic phases on the margins and in satellitic intrusions."

Jan 1, 1949

By M. Proulx

"RÉSUMÉ Le diagramme ternaire Al2O3-Sr-Y est un nouvel outil servant à l’exploration de gisements de sulfures massifs volcanogènes (SMV) archéens. Le diagramme permet de discriminer entre les roches volcaniques à minéralisations à zinc dominant (domaine Zn+) et celles à minéralisations à cuivre dominant (domaine Cu+), ainsi que les roches volcaniques ayant subi une chloritisation hydrothermale pouvant aboutir à la formation de chloritites associées aux cheminées d’altération (domaine Cl+). Ces trois domaines délimitent des zones d’influence géochimique ou d’empreintes hydrothermales résiduelles ou fossiles produites par les cellules de convection hydrothermales générées par des magmas. Le diagramme permet aux sociétés d’exploration de déterminer de façon peu coûteuse la fertilité potentielle des roches volcaniques archéennes en ayant recours à leurs bases de données et aux résultats de leurs analyses de terrain, sans aucune manipulation des données. Le diagramme ne s’applique pas aux SMV aurifères.ABSTRACT The tertiary diagram Al2O3-Sr-Y is a new tool to explore Archean volcanogenic massive sulphide (VMS) deposits. The diagram can be used to discriminate between the volcanic rocks where zinc is the dominant mineralization (Zn+ domain) and the rocks where copper is the dominant mineralization (Cu+ domain), as well as the volcanic rocks that were subjected to hydrothermal chloritization that could have led to the formation of chloritites associated with alteration chimneys (Cl+ domain). These three domains define the zones of geochemical influence, or residual or fossil hydrothermal footprints produced by hydrothermal convection cells generated by magmas. Exploration companies can apply the diagram to determine, at low cost, the potential fertility of the Archean volcanic rocks by using their databases and the results of their field analyses, without any data manipulation. The diagram does not apply to gold-bearing VMS deposits."

Jan 1, 2015

By Pierre Gaucher

It is possible to selectively mine an orebody by combining the use of the SSW probe with any bulk mining methods as well as narrow vein exploitations. In other words, thanks to the use of the SSW probe, mining operators will be able to reduce and control dilution that is generally associated to every mining operation. Already, quick and substantial savings have been obtained. Falconbridge mines have demonstrated in Sudbury and Raglan operations, that the SSW probe can log nickel, copper and iron sulphides in blast holes. They have raised the grade and reduced dilution by outlining the limits of the ore zones before selectively loading explosives in the blast holes. By lowering the probe in a blast hole, a profile of the ore content is instantly measured and recorded. Logging cored diamond drill holes at the mine have demonstrated that the ore content (nickel, copper, cobalt, PGM) as assayed is proportional to the intensity of the probe?s electromagnetic response (EM), probably because the nickel / pyrrhotite ratio is uniform within a given orebody. The probe also measures the intrinsic conductivity of the sulphides and the percentage of magnetite. All probe readings are displayed and automatically stored at a 10-cm interval within the same reading unit. A 30-meter blast hole takes less than 2 minutes to survey. The whole instrument is light (12 kg) and very simple to use. One operator can carry the SSW system and survey either down or up-holes. The probe works from ?40°C to +50°C. Plotting the measurements of the SSW probe in blast holes (2-3-4-6-10 inches in diameter) before blasting allows to determine the exact shape of the orebody within the waste rock and uneconomic low-grade ore. Thus, only the portion of the holes that contains ore is blasted. The dilution is then much reduced and, by leaving the waste and low-grade ore in place, the mine saves on transportation, blasting, crushing, backfilling, milling, etc. Thousands of dollars are thus saved. Some savings may also be achieved during the development of stopes by guiding development drifts and by replacing diamond drilling by percussion drilling. In some circumstances, when the probe shows that some of the rich ore was not drilled-off, additional blast holes will allow to recover pockets of rich ore that otherwise would have been abandoned in the walls of a stope.

May 1, 2001

By G. Vibert Douglas

NICKEL minerals are known in New Brunswick but have never been reported from Nova Scotia. The attention of the writers was drawn to an occurrence of pyrrhotite, reported to carry nickel, at the Second Gold brook, Middle river, Cape Breton. The purpose of this paper is to record the occurrence and give an account of the general geological association. In a later paper it may be possible to give greater details? than are available at present. GEOLOGY The area lies at the edge of a plateau of Precambrian rocks which forms the panhandle of Cape Breton island. This plateau has a general elevation of 1,200 feet. Middle river, with its tributaries, the First, Second, and Third Gold brooks drains the area. The lower country to east and southeast of the plateau is underlain by lower Carboniferous sediments. The rocks of the plateau are presumably of Precambrian age but have never been definitely correlated with the Gold-Bearing Series of the mainland. ?There i:s; however, some resemblance, although they have apparently been more intensely mountain-built. They are essentially fine grained, sheared quartzites and slates . The general strike is east and west, with a north dip of 45° to 55°. There are smalllocal drag-folds in the area. The only igneous rock in the immediate vicinity is an intrusive pink porphyry. It has small phenocrysts of quartz and feldspar. It has intruded the sediments generally along the structural planes, but in places crosses the structure . Its intrusive character is further proved by the fact that it contains xenoliths of the quartzite.

Jan 1, 1937

By W. K. Muwais, R. G. Cuddy

"The Lower Cretaceous McMurray Formation contains the bitumen reserves of the Syncrude Mine in northeastern Alberta. This formation comprises sediments deposited sequentially in fluvial, estuarine and marine depositional environments. The Syncrude Base Mine area consists mostly of estuarine sediments, as much of the original marine sediments have been eroded away. These estuarine deposits consist of channel-fill sediments and interchannel tidal flat sediments with the channel-fills comprising most of the orebody.Channel-fills contain, among other lithologies, interbedded sand, silt and clay rich layers that often occur as sequences of inclined beds with dips up to 25 degrees or more. A detailed knowledge of the distribution of these inclined beds, their lithological characteristics and their continuity is very important in assessing the risk of mine highwall instability . Techniques used to identify and characterize adverse structures are reviewed. INTRODUCTIONGeneralThe Syncrude Canada Ltd. oil sand mine is located within the surface mineable portion of the Athabasca Oil Sands area about 40 kilometres north of Fort McMurray in northeastern Alberta, Canada (Fig. I). The company commenced large-scale strip mining of oil sands in June 1977in the area, referred to as the Base Mine, situated in the southeast corner of the company's two lease areas (Fig. 2).The mining method (Fig. 3) utilizes large electric drag lines operating on a single bench with highwall depths up to 60 metres. Feed grade oil sand (= 6 wt.% bitumen) is mined by draglines and windrowed parallel to the highwall crest. Lower grade oil sand « 6 wt. 0J0 bitumen) occurring as waste bands is selectively mined by the draglines and cast back into the mined out pit or placed on the bench and hauled by truck. The windrowed feed is delivered to the extraction plant by a bucket wheel reclaimer and conveyor system. Stripping of Recent, Pleistocene and Cretaceous overburden units is done outside the conveyor systems by mobile equipment. The 4.5 kilometre long mine is split into four quadrants for planning and scheduling purposes, with each quadrant having an individual dragline-bucketwheel-conveyor system.Surface mining of oil sand at Syncrude requires the removal of vast quantites of material. The design of the open pit mine relies heavily on knowledge of the distribution of ore and waste materials, and on the physical characteristics of these materials.The geology of the oil sand below the dragline bench at the Syncrude Mine is complex. Geological, geotechnical and hydrogeological factors play an important role in the design and operation of the mine. This paper describes aspects of the geology that impact on the design and operation of the mine. Some of the methods and procedures adopted by Syncrude to successfully overcome difficulties that the complex geology creates are discussed."

Jan 1, 1989

By Henry Hengeveld

Are the IPCC results credible? The most recent IPCC assessment is??an admirable summary of research activities in climate science? US National Academy of Science 2001 report to President Bush Joint statement by Academies of Science from 17 other countries ? May 2001 ?The work of the?IPCC represents the consensus of the international science community on climate change science. We recognize IPCC as the world?s most reliable source of information?and endorse its method of achieving this consensus.?

Nov 1, 2002

By D. Pérez Escobar

Multiphase steels are quite sensitive to hydrogen embrittlement. Laboratory tests to evaluate this often use electrochemical, charging to introduce hydrogen into the sample, but damage purely caused by hydrogen charging has to be avoided. A ferrite-bainite steel, was charged using various conditions to identify when surface blisters occurred. Samples were also checked for internal, damage by electron microscopy. This study was repeated for three other multiphase steels and pure iron. An HSLA steel, was found to be more resistant whereas pure iron was quite susceptible to internal, hydrogen damage. For al, industrial, steels, cracks concentrated in the middle of the sample were attributed to inclusions and segregations, inherent to production.

Jan 1, 2010

By R. L. Eadie, J. L. Luo

The effect of plastic deformation on near-neutral pH stress corrosion cracking (SCC) also known as environmentally assisted cracking was studied by cracking rate measurements. All the tests were conducted in a synthetic near-neutral pH solution. The traditional potential drop tests using compact toughness (C-T) specimens with 2-3 mm long pre-cracks showed varying plastic deformation by rolling would increase the material's susceptibility to SCC. This was confirmed by cyclic loading tests using double notched flat tensile specimens with 200-300 µm long pre-cracks which gave the same results that the specimen with large scale plastic deformation by tensile loading had a relatively faster crack growth rate than that with only small scale plastic deformation.

Jan 1, 2005

By D. Kovachevich, M. A. Pfeifer

"A t remote locations typical of mines and associated ore processing plants, diesel electric generators are ideally suited for power plants due to their inherent operating flexibility, efficiency and reliability. In recent years rapid escalation in fuel and related transportation costs has made extensive waste heat recovery from generating sets financially attractive to a much greater extent than previously.The paper outlines key considerations during planning and design stages for utilizing the various waste heat sources available to best advantage. Based on two /980 mining projects built in the Canadian Arctic, data is presented on potential operating and capital costs savings. A review of heat balances, engineering flow diagrams and major equipment selections for process and building heating systems utilizing waste heat is included.IntroductionResource projects increasingly occur in remote areas requiring on-site self sufficiency in electrical power generation. For such projects, the low- or medium-speed turbo-charged diesel engine is very often the preferred choice as a prime mover for the generating sets . It is inherently reliable, has good response to load changes and has comparatively high fuel efficiency over a wide load range . From a project execution standpoint, It is capital cost- competitive and procurement lead-time normally ' fits ' within tight schedule constraints. In addition, its potential for waste heat recovery is excellent , particularly in northern climates where space heating requirements are usually substantial, and also where there a re requirements for heat for process and plant services.The high cost of fuel , with add-on transportation costs , provides a major incentive to fully exploit the available waste heat recovery potential o f such installations.As a result of the rapid escalation in the price of petroleum products following major crude oil price increases in 1973 and again in 1978-79, liquid petroleum fuels, having the desirable properties of comparatively high heat content and transportability, are no longer 'cheap' commodities and have become so valuable that industry has widely undertaken serious conservation efforts.Currently, it appears that petroleum cost trends of the 1970s may not continue, at least in the near term, and that we may see somewhat reduced energy costs for a time. In the longer term , and certainly within the life spa n of major projects, however, it is generally believed to be inevitable that these fuels will be increasingly expensive . Energy costs are today a major operating cost for remote minerals processing plants and will remain so for the foreseeable future.In order to meet the economic challenge posed by high energy costs, future projects should be thoughtfully planned from the outset with the goal of minimizing energy requirements and maximizing the use of waste heat recovery to meet such requirements. There is also considerable potential for significant energy savings by retrofitting of existing installations."

Jan 1, 1984