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By Bob Drew, Goran Vukovic, Bojan Zivanovic, Klaus Gamweger

Reaction bath temperature is a major factor in processing liquid metals and in many applications where a balance between process duration and temperature has to be found to run a procedure efficiently. Also extremes of temperature can decrease the output of a process if too cold or even make it impossible, conversely overheating can be detrimental to both the product and furnace integrity. With the help of the new online temperature measurement system very accurate monitoring of the process is possible in contrast to the current routine practice where the temperature is measured periodically with dip thermocouples. The system works with a digital, fiber optic pyrometer, which is embedded in a refractory housing. Installation in the lining is possible below liquid level as nitrogen is blown to keep the system open and to ensure continuous sight from the optical head of the pyrometer to the molten metal through the tuyere. This permanent temperature measurement gives optimal process control with the potential of taking appropriate actions at an early stage enabling proactive process control. Therefore energy savings and even process endpoint detections can be realized.

Jan 1, 2015

By E. A. Cleveland

A glance at the map discloses the fact that the Pacific Great Eastern railway either traverses or crosses some of the most important rivers of the province: the Squamish with its branches the Stawamus, Mamquam and Cheakamus; and the Green, Lillooet, Birkenhead, Fraser and Quesnel rivers. Each of these and some of their tributary streams, having their ?sources and upper reaches in the higher altitudes in regions of abundant snowfall, is capable in greater or less degree of furnishing water under suitable heads for the economic production of power. Beginning at its present terminus at Squamish the railway has the only hydro-electric development within its territory among the whole list of streams mentioned. A 225 horsepower installation at the edge of the East branch of the Squamish river, using water from Stawamus river, a branch of the former, under a head of 418 feet, is a modest beginning. Two or three additional sites, where water may be used under somewhat similar heads, may be found on this little stream. Next above Squamish, along the route of the railway, is the Mamquam, a long tributary of the Squamish from the eastern slopes. It has a drainage area of something like 130 square miles with widely varying discharges of from less than 50 to about 14,000 cubic feet per second. The preliminary investigations so far have disclosed no suitable storage sites, so the Mamquam may be regarded as a small continuous power stream - probably less than 1000 horsepower.

Jan 1, 1925

By Deni Côte, Marcel Vallée

"The Guide to the Evaluation of Gold Deposits reviews the successive evaluation steps in the domains of geology, engineering, and economics. The Guide analyzes, in a systemic perspective, the sequence of exploration, development, and evaluation work required to bring a mineral deposit to production. The aim is to identify the metal/mineralization losses and ore dilution that each work step contributes to the evaluation and mining process. The procedure allows one to maximize the income and profits of a mining operation, and to reduce the risks of financial losses tied to investment decisions in the mining sector. For greater efficiency, the criteria of reserve estimation and classification should be integrated with the evaluation steps and methods. At earlier stages of deposit development, when quantitative knowledge is available mainly on the geological axis, the term ""delimited mineral deposit"" should be used. The term ""reserve"" should be used only in an operating mine or in a mining project, when information in the geological, engineering, and economic domains is adequate to ensure technical and financial feasibility. ""Reserves"" are by definition ""mining reserves"". Each category of proven/probable reserves and measured/indicated deposits should be subdivided into two classes to express better the many steps of mineral valuation. The category of ""possible reserves"" shall be replaced by that of ""inferred mineralization"". This system, derived from the Australasian Code, can easily be integrated into current practices of the exploration and mining industry within a short timeframe. The proposal to develop the use of the margins of error of the estimates at a confidence level of90% should be viewed in a longer timeframe. Establishing the precision of the mineral inventories and distinguishing between categories and classes by means of the margin of error will require more work and a longer break-in period.SOMMAIRELe ""Guide d’évaluation des gisements d'or"" analyse, dans une approche systémique, les travaux d'évaluation et de mise en valeur des gisements minéraux dans l'axe de la géologie, dans l'axée l'ingénierie et dans I ‘axe de l'économique. L’objectif est d'identifier la contribution aux pertes de métal et à la dilution du minerai des diverses étapes de l'évaluation et de l'exploitation du gisement. Ceci aid erra à maximiser les revenus et les profits, et ainsi, à réduire les risques départe financière que comportent les décisions d'investissements dans le secteur minier. Pour atteindre ces objectifs, iI est essentiel de relier les critères d'inventorie et de classification des réserves aux méthodes d'évaluation des gisements. Aux stades antérieurs du développement minéral, lorsque les connaissances quantitatives ne s'étendent qu’à l'axe géologique, le terme ""gisement délimite"" sera utilisé. Le terme ""réserve"" ne sera utilisé que dans une mine en exploitation au dans un projet minier, lorsque l'information dans les axes de la géologie, de l'ingénierie et de l'économique sera appropriée pour en garantir la faisabilité technique et économique. Chaque catégories des réserves, prouvée et probable sera subdivisée en deux classes pour mieux qualifier les niveaux d'évaluation du projet. La catégorie actuelle des réserves possibles sera remplacée par celle des ""minéralisations inférées"". Plusieurs essais démontrent que le système propose, qui s'inspire du Code australasien, peut facilement et rapidement s'intégrer dans les pratiques de l'industrie. II pourrait également contribuer à une standardisation des méthodes et des nomenclatures à l'échelle internationale. La proposition d'utiliser les marges d'erreur des estimes au niveau de confiance de90%pour caractériser les estimations se situe dans une plus longue perspective. Cette application demandera des développement méthodologiques additionnels ainsi qu'une période de rodage."

Jan 1, 1992

By K. G. Wheeland, K. G. Byberg

The occurrence of a secondary, dust-fuelled explosion following blasting of sulphide ores has been reported in mines in many countries, including canada, the USA, Australia and South Africa. However there has been little effort to document the events and develop effective control technology. Following a detailed investigation of an incident at the Geco Di vision of Noranda Minerals Inc. , the company held a conference of interested parties in October 1986 to review the state-of-the-art and to agree on action. '!his paper outlines the causes and effects of such explosions, the key conference points and conclusions, and subsequent information-exchange and teclmology-developrnent activities.

May 11, 1988

By C. A. Sosa-Blanco

Minera Sabinas in central Mexico treats a complex sulfide ore containing galena, chalcopyrite, sphalerite and argentite as valuable minerals, and in some cases important amounts of non-magnetic pyrrhotite. For high pyrrhotite ores, results obtained by selective flotation showed good grades and recoveries in the lead-copper circuit, but a commercial zinc concentrate could not be produced due to the high floatability of pyrrhotite. When this is the case, an alternative method was proposed to produce a bulk concentrate by flotation which is then leached to recover copper and zinc from liquor in a SX-EW circuit. Leaching was conducted in an autoclave in order to study the effect of temperature and pressure, but bioleaching tests were also conducted. Leaching lead-silver residues were treated by cyanidation in order to recover silver values. The results obtained by selective flotation and by bulk flotation with leaching of the bulk concentrate showed that the latter alternative increased zinc recovery by 30 % with similar recoveries of the other metals.

Jan 1, 2007

By E. R. Rivenbark

"The coal handling plant represents an investment of about $100 million in coal handling and storage equipment. The coal receiving is done by a continuous ship unloader that can handle ships in the 60 000 T range at Q rate of 1750 /ph. A unique feature in the system is a stacker/reclaimer unit which will work inside a dome storage structure. The coal for the unit will include any low sulphur coal that can be delivered by sea at an economical price blended with New Brunswick high sulphur coal.ThE flue gas scrubber is a wet limestone system capable of 95% SO2 removal. The scrubber will utilize about 150 000 tonnes of limestone per year and will produce commercial grade gypsum by the forced oxidization method.IntroductionWith the need for new generating capacity being required, New Brunswick Power reviewed, in 1985, its options for the next unit. The study indicated that the most attractive option for New Brunswick Power would be a coal-fired unit capable of receiving imported coal at a sea port. The site selection process resulted in three site options being considered.The existing Coleson Cove and Dalhousie sites, and the Belledune site were considered. To meet load distribution needs, it was then decided that the unit had to be located in the northern section of the province, thus eliminating the Coleson Cove site. The Belledune site was selected because it had the capacity to have additional units added where as the Dalhousie site would have only been able to accommodate one unit"

Jan 1, 1994

By George H. Hope, Steve Ciccone

"The Red Dog Mine is both the largest known zinc reserve and the largest zinc producer in the world. The mine started in 1989, and by 1999 had increased production from approximately 300,000 tonnes per year (t/yr) of zinc concentrate to in excess of 900,000 t/yr. The VIP Mill Optimization Project further increased zinc concentrate production to 1.1M t/yr while improving both product quality and zinc recovery. The Mill Optimization project also addressed a number of issues related to risk reduction: power generation capacity, water treatment capacity and concentrate thickening. The project was faced with numerous challenges, the most daunting of which was the schedule. This US$105M project was executed, from conception to completion, inside of two years. Less than nine months elapsed from concept to delivery of materials and equipment to site. The project also faced a 100-day ice-free shipping window, the challenges of construction in an Arctic environment, and an extremely tight labour market for qualified craft personnel. These challenges were successfully addressed with several innovative approaches to project execution, including an Alliance contracting arrangement between the owner, engineer and contractor; full integration of the team; construction of modules in Anchorage; and fast-track engineering, procurement and construction.INTRODUCTIONThe Red Dog Mine, which began operations in 1989, is located above the Arctic Circle in Northwest Alaska, approximately 145 km north of Kotzebue (Figure 1). An 80-km road connects the mine site to the DeLong Mountain Transportation System (DMTS) port site. Red Dog is the largest known zinc deposit in the world, with known reserves totalling 94.5M tonnes, and is the largest zinc producer with a concentrate production rate of more than 1.1M t/yr.Open-pit mining is by typical drill, blast and load operation using moderately sized mining equipment. Ore is processed through conventional crushing, grinding, and flotation to produce separate lead and zinc concentrates. Filtered zinc and lead concentrates are trucked year-round to the DMTS port site, where they are stored in two A-frame buildings, 330 and 440 m long. A lightering barge system is used to transfer concentrate from the shallow water load-out to deep-sea vessels anchored approximately two miles offshore. Shipping is limited to a 100-day, ice-free window beginning in early July."

Jan 1, 2003

By Brian Hall

For some years, the mining industry has been consistently delivering returns below the market average. One of the causes is a disconnect between what is perceived to drive value creation by many industry analysts and senior corporate executives, and what actually drives the intrinsic value of mining operations. The perverse effect is that strategies that should increase value are perceived to have the potential to drive share prices down, and vice versa. This paper challenges common perceptions of what drives a mining company?s value. Anecdotal evidence suggests that the key drivers of value in the market, and hence in many boardrooms, are such things as increasing the reserves and production rate, and reducing unit operating cost. However, while the quoted reserves may satisfy ore reserves reporting code requirements to be economic, this does not imply that they are optimal. Often, a proportion of the quoted reserve reduces the potential value of the operation. Metal price increases, increased production rates, and operating cost reductions are all seen as conditions or actions that can improve value, and lead to cutoff grade reductions, thereby increasing ore reserves. However, modern cutoff theory and studies conducted by the author and his colleagues show clearly that, while breakeven cutoff grades will fall in these circumstances, optimum cutoffs may be much less volatile, and may even increase. Results from case studies indicate that value is maximised by right-sizing, not maximising, the production capacities, and by optimising the cutoff strategy. Values of many existing underground mining operations can be increased significantly by a substantial cutoff grade increase. Also, an increase in downside risk, and hence reduced returns, can occur using typical life-of-mine planning strategies if prices received are lower than predicted. Since this is often the case, low industry returns may be a direct result of typical strategic mine planning processes. Relatively simple cost-effective techniques are available to provide senior decision makers with information needed to assess the tradeoffs between their many conflicting corporate goals, and the balance between risk and reward. Often this information is not being generated at all. If it is, decisions affecting the value of the company are occurring by default at relatively low levels within the hierarchy, with senior executives apparently unaware of them or their potential impact. The paper concludes that without a re-evaluation of the way mining projects are valued, to demand proven value optimisation from mining plans by boards and mining analysts, the industry will continue to deliver below average returns.

May 1, 2003

By Dan Miners

"This presentation will provide an overview and understanding of Mine Safety and Health Administration (MSHA) and Ontario Regulations for Mines and Mining Plants. It includes discussions on the history and practical development of the standards and an overview of engineering best practices from a construction, maintenance and operational viewpoint. INTRODUCTION Ontario is one of the safest mining jurisdictions in the world and has some of the most comprehensive regulations for the construction, operation and maintenance of a mine. In the USA, several operators have adopted some or all of the practices prescribed by the Ontario Regulations as an internal procedure. Experience has demonstrated that these plants are indicating less unplanned downtime and fewer issues with MSHA inspectors in their hoist plants. HISTORY AND THE REGULATIONS Both Canada and the USA have had some form of laws governing the operation of mines since the late 1890s. The paths of legislation have run in reasonably parallel lines, continually improving the health and safety conditions in the mining industry. Ontario Mine Health and Safety In the 1970s the accident rates in mining were higher than any other industrial sector; this prompted a Royal Commission on the Health and Safety of Workers in Mines (the Ham Report). The recommendations of this report, published in 1976, generated several changes in the regulations regarding worker safety in mines. Following the release of the Ham report, the Occupational Health and Safety Act (OHS) was passed by the Legislature in 1978. The Act is a set of comprehensive laws governing almost all Ontario workplaces, and it replaced separate laws governing different industrial sectors. OHS is enforced by the Ministry of Labour (MOL), and this discussion will focus specifically on Ontario’s Occupational Health and Safety Act, R.R.O. 1990, Regulation 854, Mines and Mining Plants, Part X Mine Hoisting Plant (Ontario Regulations). USA Mine Health and Safety A coal mine explosion in West Virginia and medical studies on occupational disease led to the 1969 Federal Coal Mine Health and Safety Act (Coal Act). The Coal Act was the most comprehensive and stringent Federal legislation governing the mining industry to date. The Mining Enforcement and Safety Administration (MESA) was formed, following the 1973 Act, as a new departmental agency to assume the enforcement of safety and health in mines. The Federal Mine Safety and Health Act of 1977 (Mine Act) transferred enforcement responsibilities from the Department of the Interior to the Department of Labor and named the new agency the Mine Safety and Health Administration (MSHA). This agency enforces the Code of Federal Regulations (CFR), and this discussion refers to CFR Title 30 Mineral Resources, Chapter I Mine Safety and Health Administration, Department of Labor, Subchapter K—Metal and Non-metal Mine Safety and Health (MSHA)."

Jan 1, 2019

By George A. Lawrence, J. C. McHardy

"Field operating experience with an improved flotation mechanism for handling various flotation applications is covered in this paper. Some aspects of designing flotation machines are also presented. Operating data from extensive testing of commercial size equipment under actual plant operating conditions in the following applications is detailed:1. Copper Flotation2. Fine Coal Flotation3. Base Metal Sulfide FlotationDesign features, design improvements, modifications tested, and overall performance data are reviewed. Some mecl1anical performance data as well as metallurgical performance results are presented. Some comparisons with conventional flotation equipment are reported in this paper.Flotation sizing theories are reviewed and an actual equipment selection ex2.mple is presented. Scale-up criteria used for developing large cells are briefly covered.The paper concludes with a brief review of anticipated future flotation equipment design needs. IntroductionThe mining/milling industry is faced with increasing pressure to cut costs while maintaining product quality and indeed, in some instances, expanding production. For copper, nickel, iron, molybdenum, lead and zinc sulphides, coal, phosphate and some other minerals;, flotation remains the primary method of concentration and recovery of the valuable mineral away from the gangue. Cost reduction in flotation can be broadly focused on two areas:1. Flotation Chemicals2. Flotation Equipment"

Jan 1, 1985

By D. F. Coates

Slope problems arise on mining properties from cuts for roads and railroads and from open pits. When it is 'realized that 1,000,000 extra tons of waste may have to be mined as a result of an average slope being reduced by 1 ° it is easy to appreciate that the slope problems connected with open pits are of far greater importance than the others. The type of slope failure that can occur can be classified in different ways. The most useful classification would be one that separates the causes in such a way as to provide a basis for studies to deal with problems of prevention and control. Using this criterion the types of slope failures are classified into four groups. Having classified the problems in this way an understanding can be gained of the various mechanisms involved in failure ..

Jan 1, 1961

By Olli Haavisto, Juha Timperi

"Accurate on-line assays of mineral slurries are the basis for effective operation of flotation circuits. Typically the elemental content measurements are obtained by an X-ray fluorescence (XRF) analyzer, which samples the process lines and performs the analysis concurrently line-by-line. For a more frequent measurement of each slurry line the XRF measurements can be complemented with reflectance spectrum information. In reflectance spectroscopy the absorbance properties of the slurry in the visible and near-infrared wavelength range are analyzed. The advantage of reflectance spectroscopy is that measurements can be obtained quickly and simultaneously from several slurry lines. However, since the shape of the spectrum is only indirectly affected by the slurry elemental contents, frequent calibration of the measurement against the XRF analyzer is necessary. This study elaborates the combination of reflectance spectrum analysis with XRF. Results of laboratory tests for different slurries are presented and the operation of the system in a copper-zinc flotation plant is demonstrated.IntroductionElemental analysis of mineral flotation slurries is the most important factor in evaluating the performance of concentration processes. Timely on-line assays are also used as the basis for controlling the circuits and ensuring that the grade and recovery targets are reached. X-ray fluorescence (XRF) is the dominant technology in on-line elemental slurry analysis, and typically centralized XRF analyzers are used. The advantage of a centralized analyzer is that one measurement probe can be used to acquire the data from several slurry lines. This reduces the overall operating cost of the system when compared to distributed analyzer system design with several measurement probes requiring maintenance and spare parts. Slurry samplers are installed in the interesting process flows and representative sample flows are brought to the analyzer, where the slurry is further sampled and measured consecutively by the XRF analyzer. Due to the centralized structure of the analyzers and consecutively measurement of the sampling lines the sampling interval per slurry line can be relatively long. In larger concentration plants with several sampling lines a typical assay interval is in the range of 10-20 minutes."

Jan 1, 2016

"Discrete Fracture Network (DFN) modelling has increasingly being used in many geotechnical and mining engineering problems, the authors believe there is an ever greater demand to provide updated guidelines that address the collection of discontinuity data in the specific context of DFN models. In general terms, the generation of a DFN model requires collecting information on i) fracture orientation, ii) fracture intensity, iii) fracture length and iv) fracture terminations. The International Society of Rock Mechanics (ISRM) suggested methods for the quantitative description of discontinuities in rock masses directly include most of these parameters. However, there are important differences engineers should be aware. To what extent discontinuities can be sampled and which limitations are inherently introduced in the analysis by the sampling methods being adopted represent important aspects that should drive the collection of discontinuity data for DFN analysis; this will require the introduction of a more appropriate set of guidelines bridging the gap between the current, very practical, ISRM methods and the data requirements imposed by the use of new DFN technologies.INTRODUCTIONThe last decade has seen a major increase in use of the Discrete Fracture Network (DFN) approach, both as a stand-alone tool or integrated within more complex geomechanical simulations (Rogers et al., 2014 and Elmo et al., 2014). In particular, the DFN approach offers the opportunity to maximise the use of fracture data collected from mapping of rock exposures and to construct synthetic rock mass (SRM) models. However, the potential of DFN based modelling is limited if there is insufficient care in collecting the necessary structural data at the required engineering scale. DFN models are also subject to the process of data calibration and validation (Hadjigeorgiou, 2012). With DFN modelling becoming an almost integral part of many geotechnical and mining engineering problems, the authors believe there is an ever greater demand to review the process of collecting fracture data in the specific context of DFN modelling.The value of the DFN model depends directly on the quality and quantity of available field data. For example, fracture length (persistence) is an important parameter in DFN modelling; however, this parameter is either seldom available at the pre-feasibility stage due to a lack of exposures (man-made or natural), or engineers have access to limited length data collected along exploratory drifts. Characterisation of rock exposures should also take into account limits of window/scanline mapping techniques with respect to both trace length bias and the effect of cut-off assumptions inherent in the mapping methodology."

Jan 1, 2015

By M. F. Ameur, M. Habak, H. Aouici, M. Kenane

Present study interest by aluminium alloy (Al 7175-T5173) drilled without cooling fluid. The influence of the machining parameters (spindle speed and feed rate) on the holes quality was analyzed. Drilling tools are made of carbide (WC); high speed steel (HSS) and TiN coated carbide (WC-Ti).The Experiment design was reinforced by the application of statistical analysis of variance (ANOVA).The results show that the thrust force is influenced principally by the spindle speed and feed rate. Though, both feed rate and tool materials have statistical significance on the surface roughness. In addition, the objective of correlations between spindle speed and feed rate with the evolution of the machining parameters was established. These correlations were obtained by quadratic regression using the response surface methodology. Finally, useful to select optimum values of drilling parameters, that would minimize thrust force, torque, cutting temperature and surface roughness.

Jan 1, 2015

By Arthur M. Whiteside

Discussion of the laws bearing upon the economics of mining in this province at once resolves itself under three headings: (a) The rights and obligations of holders of mineral bearing lands; (b) Taxation of mines; (c) Regulation of methods adopted in financing mining operations. Titles: The law relating to titles is contained in the Mineral Act, Placer Mining Act and Coal Mines Prospecting Act. Origin: Mining laws in force in this province and elsewhere on the continent had their origin in the rule-of-thumb regulations adopted by prospectors themselves, when, far from the centres of civilization and the seats of the courts of justice, they found it necessary, for mutual protection, to fix the conditions of possession by right of location, and to prescribe the duties to be performed in order to enable the individual to maintain his ground against all comers. These regulations have been codified and added to by legislatures, until we find adequate protection and safeguard to property in the laws of this province.

Jan 1, 1924

By H. R. Shakeri, R. Mayer, M. J. Worswick, A. Rahem

The current focus of research and development in transportation industry is to use lightweight materials such as aluminium alloys for more structural components. In this regard, maintaining safety of the passenger and vehicle is the most important; therefore crashworthiness of components made of lightweight materials must be evaluated prior to sizable application of these materials. The focus of the present study is to understand failure and damage mechanisms during the axial crushing of aluminium tubes made of A1Mg3.5Mn alloy of 2 and 3.5 mm thickness. Due mainly to complexity of the crushed tubes, a microstructural approach is considered. In this study optical, stereo as well as scanning electron microscopy techniques have been used to study damage and failure mechanisms in these types of tubes, which are essential energy absorbing components in passenger vehicles.

Jan 1, 2006

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 Kristine Haug

Although most in situ operations in Alberta do not encounter significant problems during resource extraction, there have been a few documented occurrences of oil or steam releases as a result of compromised caprock seals. The objective of the Oil Sands Caprock Integrity Project (OSCRIP) is to characterize the units above and below bitumen zones to determine which geological factors affect the quality of the caprock seal. In addition, geomechanical properties and stress measurements of the bitumen reservoir and overlying units will be examined to provide a better picture of the containment conditions in which in situ operations occur. The information from this study will aid regulatory staff and industry in determining the zone-specific geological and geomechanical factors that could affect the design, operation, and feasibility of in situ recovery projects. The OSCRIP study area (Townships 87 to 99 and Ranges 1 to 13, West 4th Meridian) encompasses the surface mineable area, the northeast extent of the Wabiskaw-McMurray bitumen deposit and the Clearwater Formation, as well as a wide band of the Devonian salt-dissolution zone. Regional geological mapping of the Cretaceous strata focuses on the spatial extent and thickness of the caprock seal. Mapping of the underlying Devonian strata is targeted at better understanding the potential effects of salt dissolution and collapse of overlying strata on the integrity of the caprock seal. Examination of LiDAR (Light Detection And Ranging) bare earth DEM in the study area has revealed localized depressions that may represent sinkholes rooted in subsurface collapse features in Devonian carbonate and evaporite strata. Mapping the location and understanding the timing of salt dissolution-related features and deformation in the Devonian strata will help address questions about the possible effect that geological structures, such as sinkholes, have on the integrity of the caprock, as well as the potential for localized variations in the stress regime of the bitumen zone and overlying units. The stress regime in units above 350 m is such that any induced fractures are believed to be horizontal, and therefore, there would appear to be no mechanisms that would allow these fractures to reach the surface. However, recent incidents have shown that vertical pathways can occur, linking the subsurface to the surface. The final phase of the project will evaluate the changes that may occur in the stress regime under thermal operating conditions in the study area.

Jun 1, 2012

By Brad Thrall, Howard Bradley, Michael Samuels

"LOCATIONViceroy Minerals Corporation owns and operates the Brewery Creek heap leach gold mine located approximately 55 kilometers northeast of Dawson City, Yukon Canada. Dawson was home of the Klondike Gold Rush 100 years ago. Upon startup in November 1996, the Brewery Creek Mine was the northernmost operating heap leach gold mine in North America and one of the most northern in the world. Located at 64"" 02' latitude, the mine is less than 300 km south of the Arctic Circle. Access to the mine is available at Kilometer 14 of the Dempster Highway, linking Inuvik, NWT and the Klondike Highway, 40 kilometers east of Dawson City. The immediate vicinity is the only part of Canada not glaciated in the Wisconsin advance, which has resulted in an oxide ore deposit due to approximately 80,000 years of weathering - an area unique in Canada.DESCRIPTION OF OPERATIONSIn order to utilize heap-leaching technology successhlly in an extreme northern climate, a number of design features were incorporated into the process flow sheet to operate on a year round uninterrupted basis. Winter temperature may dip below minus 50 ""C, demanding an approach to mining and leaching that is different from heap-leach operations in more temperate climates. Because of the severe winter temperatures, the mine operates approximately 2 10 days per year, while the leaching process is continuous on a year round basis. Run of mine ore (ROM) is placed on the heap beginning in mid April until late October. Overall gold recovery is projected to be 78% over a 325 day leaching cycle with annual production levels of 2.3 million tonnes of ore placed on the pad, with an average of 75,000 ounces of gold recovered per year. The recovery process utilizes conventional sodium cyanide leaching, carbon adsorption, high pressure stripping, thermal reactivation and acid washing, and on-site smelting.HISTORYFollowing a comprehensive governmental and public review of the proposed project, a Class A Yukon Water license was issued in August, 1995. Construction started in 1995 and leaching commenced in October 1996.A Socio-Economic Accord with the Tron Dek Hwech'in First Nations provides for employment, contract, and scholarship opportunities for First Nations citizens."

Jan 1, 1999

By J. A. González-Anaya, F. Nava-Alonso, O. Alonso-González, F. Alvarado-Hernandez, A. Uribe-Salas, C. Jimenez-Velasco

"One of the most common hydrometallurgical methods for precious metal extraction is cyanidation. The effluents of this process may contain relatively high concentrations of copper, zinc and iron, which react with free cyanide to form complexes, adversely affecting the efficiency and the economy of the process.This preliminary work studies the use of the solvent extraction technique to remove copper, zinc and iron cyanide complexes from a synthetic solution similar to that of gold mill effluents, in order to allow the recycling of the solution back to the process. For the extraction of these anions (Cu(CN)2 -, Cu(CN)3 2-, Cu(CN)4 3-, Zn(CN)4 2- and Fe(CN)6 3-), trioctyl methyl ammonium chloride (Aliquat 336) was studied as extractant, using nonylphenol as modifier in the organic phase (iso-octane). The experimental results showed that for a synthetic solution containing 450 mg/L total cyanide, 160 mg/L copper, 50 mg/L zinc and 51 mg/L iron, it is possible to extract the 96% of copper, 91% of zinc and 75% of iron when using 0.011 mol/L of Aliquat 336 (organic/aqueous volume ratio (O/A) =1) in the pH range of 9-10."

Jan 1, 2014