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By Stephen Mcgibbon, Tim Twomey

"Abstract - The High-grade Zone (HGZ) was discovered 5000 ft (1520 m) below surface in the hangingwall of the existing orebody, 46 years after the Red Lake mine first went into production. The very rich ore of the HGZ is characterized by a remarkably abundant distribution of visible native gold. The location of this discovery challenged conventional wisdom at the time and its genesis has yet to be fully understood. Textural observations of ore within carbonate veins as well as crosscutting relationships suggest peak-metamorphic emplacement for at least some of the gold. Post-lamprophyre dike remobilization of gold is locally observed in the HGZ. Structure and dilatancy were the key elements for localizing ore at the Red Lake mine. Ore occurs where a fault trend intersected folded ultramafic volcanic rock that created a semi-permeable cap-rock to ore fluids ascending the "feeder" structure. This was enhanced by strong competency contrasts between the eastern ultramafic rocks, felsic volcanic rocks west of the HGZ, and the mafic volcanic host to ore - an exceptional environment for the development of protracted dilatant fluid pathways for gold deposition.Development in the HGZ began in February 2000 and reached commercial production on January 1, 2001 at a capital cost of US $53 million. December 2001 reserves are 1.9 million short tons (1.73 Mt) at an average cut and diluted grade of 2.05 ounces per ton gold (70.5 g/t) containing 3.8 million ounces of gold. The extremely rich ore presented a unique challenge in grade estimation for the Geology Department at the mine. The historic cutting factor was replaced by a statistical method as more data were collected from mining and mill reconciliation. The mine produced 503 000 ounces of gold in 2001. Exploration at the mine is targeting HGZ-type ore formation within basalts associated with the intersections of fluid pathways and folded ultramafic rocks, as well as other targets."

Jan 1, 2001

By A. B. Parsons, P. G. Howes

"This article discusses how recent changes in the federal and Quebec .income tax laws have contributed to an improved investment climate for mineral exploration in the Province of Quebec. Individual investors who are resident in Quebec and who are in the highest tax bracket (1984-60.4% marginal rate) may obtain tax benefits that result in only nine cents of each invested dollar being at risk.IntroductionIn a recent submission by the Mining Association of Canada to the Royal Commission on the Economic Union, it was stated that the mining industry ""is no longer discovering and opening new mines at rates sufficient to offset the depletion of existing orebodies and to maintain pre sent output"". With world metal prices still in a depressed state following the prolonged 1981-82 recession, moreover, the continuing success of Canadian mining in world markets will depend on this country's ability to compete in a new environment characterized by subsidized Third World production . For the most part, this new competitive environment will encourage the development of cost-efficient mines that are better equipped to withstand the troughs and valleys of international metals prices."

Jan 1, 1984

The AG/SAG circuit discharge P80 is now increasingly referred to as the “Transfer Size” or T80 for short. From the literature it is apparent that in circuit design some approaches to the sizing of AG/SAG mills as well as the ball mills that they feed use this parameter. This paper reviews whether the use of the T80 is appropriate in this context. In the course of the review examples of AG/SAG discharge size distributions measured from range of operating circuits are used to illustrate the arguments made.

Jan 1, 2012

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

This paper examines the latest advances in mine hoist motor and drives systems. The technology employed for large hoists has migrated from the traditional DC technology to AC motors with cyclo convertor drives, and more recently, advances in pulse width modulation (PWM) drives have resulted in these being applied to large hoist drives. When combined with PWM drive technology, the induction motor presents the ideal solution for hoist applications This paper examines the factors in choosing a suitable PWM drive and motor for a hoist installation. Factors under consideration include: ? hoist duty cycle, ? drive rating restrictions, ? choice of power semiconductor device,, ? low speed operation, ? maintenance ? reliability The cage induction motor and synchronous motor are compared and it is shown that the induction motor is the motor of choice for large hoists.

May 1, 2010

By R. A. Frith

"Belts of Yellowknife Supergroup volcanic and sedimentary strata in the Slave Structural Province are separated by granitoid complexes. The strata and most intrusive rocks are 2.7 and 2.5 Ga old, but rocks around 3.1 Ga have been recognized in some of the complexes and are believed to represent a once-extensive sialic crust. Volcanics were erupted along rifts in this crust and the rifts became sites of crustal foundering and the development of troughs that filled with turbidites of volcanic and granitoid provenance. Present margins of the granitoid complexes may be close to the original margins of deposition of volcanics, with associated mineral deposits, and close to the thickest parts of basins of sedimentation.The Hackett River volcanic belt extends 100 kilometres between Mara River and Back River and is crudely S-shaped, with a northern sector surrounding a core of granitoid basement rocks, a northeasterly facin g central sector and a southerly facing southern sector. Up to 8 kilometres of andesitic volcanics with intercalated felsi c volcanic rocks are preserved within the central sector. The f elsic rocks include thick lenses of volcaniclastics with large, quartz-eye-bearing clasts, but the known metal deposits are not associated with these. Both of the deposit areas, the Hackett River area in the northern domal sector and the 'A itch ' Lake area 40 kilometres to the south in the central sector, are near the tops of relatively thin atypical volcanic sequences above suspected basement rocks. The Yava deposit near 'A itch , Lake overlies a unit of subaerially deposited, welded, andesit ic ash flows and the Hack ett River deposits overlie highly metamorphosed volcaniclastic rocks that include suspected ignimbrites.The deposits are notably argentijerous and lead-rich. They consist of stratigraphically zoned sheet-like bodies of iron sulphides, sphalerite, galena and chalcopyrite underlain by altered rocks containing chalcopyrite stringers. The Yava deposit was formed where hydrothermal fluids exuded through the fractured floor of a flooded caldera basin. The Hackett River deposits may have been formed in a similar setting and it is not inconceivable that all the known deposits in the belt were formed in a single large caldera basin, although there is no independent evidence for the required major fault separation between the Hackett River dome and the 'Aitch' Lake area."

Jan 1, 1980

By R. A. Nemchek

Over the years, concentrator plant design has evolved from a large number of small grinding mills to a small number of large mills. In many cases, all of the tonnage runs through a single mill (typically a large SAG mill), so that the plant’s performance hinges on the productivity of this one machine. Industry specifications attempt to address the critical nature of today’s grinding mills in a manner that is often overly complex, neglects economics, and is not clearly focused on the end user’s goals. This paper surveys current industry practices, and proposes an improved approach to standards writing recognizing that product design, procurement, manufacturing, and quality are all inter-related in contributing to a project’s success. The lessons learned here can be extended to specifications for all types of machinery.

Jan 1, 2012

By F. J. Alcock

IN the summer of 1934, gold was discovered on Lodge bay, on the north shore of lake Athabaska in northern Saskatchewan, about fifty miles east of the Alberta boundary line. The first claims were taken up by the Consolidated Mining and Smelting Company of Canada, Limited, and there was a 'rush' to locate similar showings. Staking continued through the summer and succeeding winter, and in the spring of 1935 the provincial government established a recording office at a convenient point which is central to the more important holdings and where 'planes can land in any weather. During the past summer, the name of this townsite was changed from Beaverlodge to Goldfields, and a post office was established here. The season was one of great activity; a great deal of assessment and development work was carried out and a large amount of further prospecting done. In addition to the work by private companies, geological investigation was carried out in the region by a Federal Geological Survey party under the charge of the writer and a reconnaissance examination was made of an area of some 7,000 square miles surrounding the region of particular interest. Though this was the first discovery of gold in the region it was not the first occasion that prospecting had been carried out along the north side of lake Athabaska. Over twenty years ago, a number of prospectors were at work in the area and a large number of claims were staked, many of which were never recorded. One man by the name of Piché, in the years 1910, 1912, and 1913, took up a considerable number of claims north of Pine Channel narrows, east of Fond du Lac. His discoveries, which consisted of small showings of sulphides in sedimentary gneiss, proved to be of no economic importance. In 1915, a sudden widespread interest was aroused by the report that a sample of ore collected near Fond du Lac had yielded a very high assay in silver. In March and April of that year, prospectors began to rush into the field by dog teams to take up claims, and, as soon as the Athabaska river was free of ice, others started by boat from Athabaska Landing. Some hundreds of claims were staked and recorded in the Dominion Land Office at Edmonton or at Fort Smith. By July, most of the prospectors had? left the region, having failed to find any silver ore. In 1921, considerable prominence was given to the area a few miles east of Goldfields by reports that very large masses of iron ore were available there. Claims were taken up, but the material is much too low grade to be considered commercial ore.

Jan 1, 1936

By L. E. Young

"The Red Dog deposit of the western Brooks Range, Alaska was discovered in the 1970s. Two mineralized areas are present, the Main and Hilltop deposits. With indicated and inferred reserves of 77 million tonnes of 17.1% zinc, 5.0% lead and 82 g/ tonne silver, the Main deposit of Red Dog represents one of the world's largest zinc-lead deposit s. Since serious evaluation by Cominco commenced in 1980, a better understanding of deposit geology has been gained through 10 715m of diamond drilling and concurrent geologic, geophysical and geotechnical studies. The Red Dog deposit is of Mississippian to Pennsylvanian or Early Permian age, and straddles a redox transition in fine-grained and chemical sediments of the Red Dog structural sequence.The Main deposit has been modified by regional Mesozoic thrust faulting and isoclinal folding, resulting in complex interrelationships between silica rock, sulphide rock and barite. Multiple lines of evidence suggest the Main deposit contains both a syngenetic stratiform and a replacement component. Ore fluids were probably derived by regional lateral movement of brines through a coarse clastic footwall aquifer, then upwards along block faults to the site of the Red Dog deposit.Historical PerspectiveThe region in the vicinity of the Red Dog deposit (Fig. 1) was first prospected by J. W. Kelley in the late 1880s (Orth, 1967). The first coordinated inland exploration was conducted by the U.S. Geological Survey in 1910-1911 and 1923-1926 (Smith, 1913; Smith and Mertie, 1930). The earliest reports of zinc-lead mineralization in the region include reference to samples collected at unknown locales by Eskimo prospectors (Anderson, 1944). In 1955 stratiform pyrite was discovered 19 km west of Red Dog by I.L. Tailleur of the U.S. Geological Survey (Tailleur, 1970). The first reported visit to what is known as Red Dog was by I.L. Tailleur in 1968, who was field checking a colour anomaly noted by B. Baker, a local bush pilot (Tailleur, 1970; Moore et al., 1986) ."

Jan 1, 1989

By C. Sartain

In recent years market pressures have been building on companies to develop the next era of mining projects to follow the previous boom in copper projects of the mid 90's. However the response from the industry has been slow in coming, and somewhat muted. It is clear that there simply have not been the obvious quality projects waiting to be rapidly developed. Many of the known undeveloped copper projects have particular characteristics that have previously prevented their development, including mineralogical complexity in the ore bodies, environmental challenges or particularly difficult geographic locations. This paper describes how the Copper Division of an international mining company, Xstrata plc, is preparing to progressively develop an impressive pipeline of projects, armed with an array of proprietary technologies and with a strong approach towards sustainable development and community engagement. The approach being taken is enabling Xstrata to complement its acquisitive corporate philosophy with a management emphasis on project development and operational optimization and enhancement.

Jan 1, 2007

By J. Shanks

In 1920 the writer presented some notes, embodying his experience with storage-battery locomotives as main under-ground haulage-motors at Brazeau collieries. (1) Since that date these motors have stood up well to the test of maximum output and heavy overloads, having accomplished all that was expected of them. The notes presented in 1920 gave a brief description of the conditions under which these motors were working at Brazeau collieries, also the cost, per ton mile, of operating them. The cost per ton mile has since then been appreciably reduced, by working the locomotives nearly to capacity and under more ideal haulage conditions, on both shifts. It is not the intention of the writer to repeat what was written in 1920, but rather to give members the benefit of his experience in operating different types or designs of locomotives; to draw their attention to the drawbacks of some designs, and to the improvements made in some of the more recent storage-battery locomotives put on the market, as regards efficiency, upkeep, and safety. Because of their flexibility storage-battery locomotives have advantages over any other type of haulage, where grades are suitable to their use. The number in use in the mines in the United States has increased enormously during the past few years, and this method of haulage is, at the present time, attracting the attention of British and Continental mining engineers.

Jan 1, 1924

By G. Q. Liu

"The application of oxygen-enriched cyanidation to three Canadian gold ore samples has been investigated. The results showed that the use of oxygen can improve gold dissolution kinetics, reduce grinding time, and lower cyanide and lime consumptions. To obtain the same gold extraction, the required cyanide leaching time was reduced from 48 hours in slurry containing 8 ppm O2 to 12 - 24 hours in 20 ppm O2 slurry. Reagent consumptions were reduced by 23 - 37% for cyanide and by 35 - 54% for lime. There was little advantage to further increasing the dissolved oxygen to 32 ppm from 20 ppm. Gold extraction from the +200 mesh fraction improved 4 - 14% in oxygen-enriched slurry. A general kinetic model derived from the cyanidation of three ore samples can be described by the following equation: <equation>where E is the gold extraction (%) at time t (hours), EI is the ultimate gold extraction (%) , and &apos;P and k are constants depending on cyanide concentration, level of dissolved oxygen, and the characteristics of the ore samples. Comparative studies of conventional carbon adsorption and carbon adsorption in oxygen-enriched slurry have also demonstrated that oxygen enrichment resulted in more favourable conditions for gold adsorption."

Jan 1, 1995

By D. M. Baird

ABSTRACT A revised stratigraphic section of Carboniferous rocks which occupy about 700 square miles in southwestern Newfoundland is presented. Gypsum, which outcrops at thirty-five different localities, is found to belong to four principal zones in the section. The newly mapped structure of the region makes the otherwise random occurrences of gypsum appear as systematic outcroppings of the four zones which follow the regional structure. Details of several occurrences are given and those most advantageous for exploitation are pointed out. INTRODUCTION ROCKS of Carboniferous age occupy an area of about 700 square miles in southwestern Newfoundland. They occur in a belt, from 5 to 15 miles wide, which extends from the head of St. Georges bay southwestward for 65 miles to the mouth of Little Codroy river (see Figure 1). Several hundred feet of Pennsylvanian rocks overlie rocks of Mississippian age, which are at least 12,000 feet thick. The rocks of the Carboniferous section of Newfoundland are very similar to those of Nova Scotia and represent a northeastward continuation of the same palaeophysiographic conditions. Mississippian measures of Windsor equivalence include thick gypsum deposits which outcrop at many places and which extend under large areas as indicated by sink-holes and by structural considerations.

Jan 1, 1951

By J. Carr

This paper discusses: (1) the need for Western Canadian coal in eastern Ontario Hydro plants; (2) design parameters-unit trains, year- &apos;round receiving from trains, and shipping (Great Lakes season); (3) equipment chosen-dumper-indexer, outhaul conveyor, yard belt, stacker, reclaimer, surge-bin feeders, shiploader, docking system and dust control; (4) foundation and soil conditions-dumper house, yard belt, surge bin and dock-piling-runway; (5) winter conditions- thaw shed, feeder, lump breaker, beltings (oil), and dust control and disposal; and (6) operations to date.

Jan 1, 1979

By J. F. Wright

INTRODUCTION Eighteen years ago about half a dozen experienced prospectors moved from northern Ontario to northwest Manitoba to prospect &apos;greenstone&apos; areas shown on geological maps of .parts of northern Manitoba prepared by J. B. Tyrrell, D. B. Dowling, and Wm. Mclnnes. Gold-bearing quartz was soon discovered by these men in this new field, and in succeeding years many more prospectors entered the district. A number of the pioneers are still prospecting, and since 1913 mineral deposits have been discovered each year in widely separated areas of the large district extending 150 miles eastward from the 102nd meridian and 60 miles north of latitude 54°30&apos;. The majority of the discoveries, however, have been made near Schist, Elbow, Wekusko, and Kississing lakes. One hundred or more mineral occurrences of some merit are known, the main types being sulphide replacement bodies containing nickel-copper or copper-zinc and gold-bearing quartz veins. Some underground exploration or diamond drilling has been completed on 25 or more of the prospects. Up to the present, three ore-bodies, namely, Flin Flon, Sherritt-Gordon, and Mandy, have been proved. Of these, Flin Flon, the largest, is estimated to contain from 16,000,000 o 19,000,000 tons of copper-zinc ore carrying some gold, silver, and lead. Next in importance in regard to tonnage is Sherritt-Gordon, with a calculated reserve of nearly 5,250,000 tons of copper-zinc ore carrying less than $1.00 combined gold and silver.

Jan 1, 1931

By J. R. Pacheco

Paranapanema group has decided to implement the business system SAP R/3 in all companies of the group in order to replace all current applications. This project has taken nine months to be completed. This paper describes the phases of this implementation, with focus on the Plant Maintenance component. In addition, it gives an idea of the effort required to implement SAP R/3 on an organization the size of Paranapanema group.

Jan 1, 2007

By W. D. Gould, A. Kapoor

Acid mine drainage (AMD) is characterized by low pH and high concentrations of sulfate and dissolved metals such as iron, manganese, aluminum, zinc, and copper. Chemical treatment of AMD achieves pH neutralization and toxic metal removal but also produces large quantities of bulky sludge that requires long-term storage facilities and monitoring. Chemical treatment of AMD achieves only partial removal of sulfate (SO4) and total dissolved solids. Sulfate reducing bacteria (SRB) have been used for the removal of sulfate from industrial process wastewaters. The biological sulfate reduction process generates sulfide and alkalinity. The sulfide produced in the biological sulfate reduction process is used to precipitate metals present in AMD as their respective sulfides and the alkalinity generated is used to neutralize the AMD. This review article will present an overview of biological sulfate reduction processes using SRB, bioreactor configurations, AMD treatment studies, and full-scale systems in operation for the treatment of acid mine drainage.

Jan 1, 2004

By P. Homola, M. Karlík, M. Slámová

"Aluminum sheets (AA1199, AA8006, and AA5754) were processed by accumulative roll-bonding (ARB) in the temperature range from 20 to 350°C. The microstructure of the sheets was characterized by means of scanning and transmission electron microscopy and electron backscattered diffraction. Mechanical properties were monitored by hardness measurements and tensile tests. Increasing strain (number of ARB cycles) led to incremental development of lamellar microstructure with a decrease of the spacing between high-angle grain boundaries in the normal direction of sheets. ARB process produced an important increase of strength while maintaining thickness and relatively high ductility, without accenting of the anisotropy of mechanical properties of sheets. The level of hardening decreased with the processing temperature and at 300 and 350°C ARB caused even the softening of the material due to the recovery of the deformed microstructure or partial recrystallization during heating to ARB processing temperature.INTRODUCTION Accumulative Roll Bonding (ARB) is a technique of grain refinement by severe plastic deformation (SPD) proposed by Saito et al. (1999). One ARB cycle consists in sheet cutting, surface treatment, stacking of two pieces, heating (optional), and rolling with 50% reduction in thickness. Since the sheet thickness remains unchanged by this cycle, ARB processing can be repeated as many times as desired. The goal of ARB is to impose an extremely high plastic strain on the material, resulting in structural refinement and strength increase without changing specimen dimensions. After several cycles, ultra-fine grained (UFG) materials with high strength and relatively high ductility are produced. An advantage of this method is that it does not require any special equipment as other SPD methods such as equal channel angular pressing (ECAP) (Valiev & Langdon, 2006), high pressure torsion (HPT) (Valiev et al., 2000), or cyclic extrusion and compression (CEC) (Richert et al., 1999), but only a conventional rolling mill and so it is seen as an economically viable and industrially scalable processing route. ARB processing has been successfully applied to various kinds of metallic materials at room or elevated temperatures (Tsuji, 2005). Besides processing single metals and alloys, ARB has also been used for creating ultra-fine grained and nanograined metallic composites (Wu et al., 2010; Qu et al., 2014)."

Jan 1, 2018

By Donald Leroux, Robert Grant

"Flotation is a complex and highly multivariate process. Using the conventional OFf (one-factor-at-a-time) technique, the optimization of flotation circuits through laboratory or plant testwork is difficult, time-consuming and therefore, expensive and often results in marginal improvements. The optimal operating conditions can be more efficiently estimated when a systematic approach like SDE (Statistical Design of Experiments) is taken.The concentrator of Noranda's Brunswick Mining Division (near Bathurst, New-Brunswick) is well known for the complexity of its differential copper-lead-zinc flotation circuits. One of them, the chalcopyrite-galena separation (or CuSep) circuit, is impacted by more than 20 variables.Statistical Design of Experiments (SDE) techniques were applied at the laboratory scale to improve the performance of Brunswick's CuSep circuit. Screening tests were conducted using Fractional Factorial designs while optimization tests were carried out based on Response Surface Modelling techniques like the Central Composite design. Every series of tests, without exception, revealed new information and process insights which led to significant circuit performance improvements in the plant So far, the metallurgical gain may be as high as four percentage points of copper recovery (in the CuSep circuit). Potential cost savings of expensive consumables (steam, activated carbon) have also been identified but will require additional circuit modifications before being realized.IntroductionIn spite of its apparent simplicity, flotation is a complex three-phase (solid, liquid and gas) separation process. Fundamentally, it is a highly multivariate process. Industrial flotation circuits are commonly affected by 10 or more process variables."

Jan 1, 1997

By A Frostick

Ranger uranium mine is surrounded by the World Heritage listed Kakadu National Park and offsite impacts resulting from mining at Ranger would affect the Magela Creek catchment first. Radionuclides, lead isotope ratios and metal concentrations were measured in sediment cores from the Magela Creek catchment around Ranger to investigate the dispersion of mine-derived particulates. The study found a localised area within the Ranger mineral lease, where upper sediments had elevated levels of radionuclides and trace metals and radiogenic Pb isotope ratios. There is no current evidence of sediment dispersion from Ranger further downstream within the Magela Creek catchment.

Aug 1, 2010