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By F. G. Boehm, T. S. Golosinski, P. M. Tucker

"In an earlier paper(1) the visits to several European mines using the bucket-wheel excavator (BWE) technology were described. It was during this trip that information was gathered on some interesting developments related to this type of mining, taking place elsewhere. It was learned that an across-the-pit system (XPS) comprised of a BWE and stacker has been operating successfully in a Hungarian mine for some time. Also the use of stackers with 225 m long booms and draglines with 125 m booms and 125m3 buckets in Soviet mines was indicated. Such equipment could be of great value to some Canadian strip mines, in particular the equipment proven useful in severe climatic conditions of U.S.S.R., similar to those of the Canadian prairies.To follow up on this information a field trip to Hungary and the U.S.S.R. was organized by the Department of Mineral Engineering, University of Alberta, to study the applications and performance of the systems in question. Visited were the Thorez mine near Visonta, Hungary, U.S.S.R. Ministry of Coal Mining and Skotchinski Institute in Moscow, Karagandashakhstoi Institute (designers of Ekibastuz mines in the Kazakh Republic) and Kostenko mine in Karaganda, Vostsibgiproshakht Institute (designers of Irsha Borodinski, Kharanovski, Moguntski and Tugnuski mines in Siberia) and the eastern Siberian Unit of the U.S.S.R. Coal Mining Ministry in Irkutsk as well as Azeiski mine located some 250 km northwest of Irkutsk. The findings of this field trip are presented."

Jan 1, 1985

By S. Banisi, M. Poorkani, M. Farzaneh, M. Askari

"At the Sarcheshmeh copper mine 40,000 t of ore per day with an average grade of 0.9 % Cu is ground to 70% passing 75 microns. Grinding is effected in 8 parallel lines of 8 x 5 m ball mills in a closed circuit with cyclones. The make-up balls are 80-mm forged alloy steel balls and the average ball consumption is 750 gh of ore ground. In order to optimize ball size distribution inside the mill, based on the previous investigation instead of using only 80 mm make-up balls a combination of 80 and 60 mm (75% to 25% by weight) ball charge was used in one of the mills. To evaluate the performance of three ball types namely forged alloy steel balls (A), ductile cast iron (C), high chromium cast iron (D) and also a combined (80 and 60 mm) charge of forged alloy steel balls (B), four identical parallel mills were charged accordingly. These four mills were sampled during a period of six months. The amount of material finer than 75 microns of cyclone overflows was selected as a criterion for the performance evaluation. It was observed that in a mill with the combined make-up balls the amount of fine produced was 4% higher than the other mills. The consumption of ball types A, C and D were 730, 710 and 534 g/t, respectively. The results of laboratory flotation tests showed that due to an improvement in the production of fines an increase of 1.4% in the overall copper recovery is obtainable. Due to the promising results, the new make-up ball regime was implemented in all mills in the plant.INTRODUCTIONThe Sarcheshmeh copper ore body which may rank as third or fourth largest in the world contains 1 billion tonnes averaging 0.90 % copper and 0.03 % molybdenum. It is located southeast of Iran and has been processing 40,000 t/d of ore since 1982. The mine produces 100,000 tonnes of copper and 2,200 tonnes of molybednite concentrate per year. After three stages of crushing, the ore with a F80 of 12.7 mm is fed to 8 parallel ball mills in closed circuit with cyclones to produce a product 70% finer than 75 microns. The concentrate of the first stage of flotation is reground and the tailing constitutes the main component of the plant final tailings. A concentrate with an average grade of 31% Cu is obtained after cleaning and re-cleaning stages. Total recovery of the plant varies between 83 and 87 % depending on the operating conditions and ore type."

Jan 1, 2002

By K. Hoover, G. Labarre, S. Rantanen

"As part of the Namew Lake project a mill was constructed to treat 1900 tpd of ore grading approximately 0.90% CU and 2.45% Ni to produce copper and nickel concentrates.Nickel occurs mainly as pentlandite and violarite while copper occurs as chalcopyrite. Two main ore types are present1 lower grade disseminated sulphides in a talcose ultramafic gangue and a higher grade solid sulfide with a granitic breccia matrix.Primary crushed ore from underground is treated on surface in a conventional closed circuit crushing plant using 2-stage cone crushing. Crushed ore is conveyed to storage and then fed at a controlled rate to a grinding circuit employing a rod and ball mill with hydrocyclone classification. Rougher flotation separates and cleans nickel and copper sulfides from waste materials followed by a high lime separation circuit to separate the minerals into final concentrates. Dewatering is achieved through use of high capacity thickeners and pressure filters prior to delivery to a loadout area. The crushing and milling control is highly automated.Plant design was based on metallurgical samples obtained from drill cores. After the first year of operations, plant results compared favourably with design projections.INTRODUCTIONThe Namew Lake Project is a joint venture partnership between Outokumpu Mines Ltd. (Canada) and Hudson Bay Mining and Smelting Company Ltd. (60%). The project included construction of a mine and milling complex to treat approximately 500,000 tonnes per year of copper-nickel ore grading o.91% and 2.44% Ni. Known reserves are estimated at 2. 65 million tonnes. The deposit is located approximately 65 km south of Flin Flon (120 km by road) and about 5 km east of the Manitoba-Saskatchewan border. The decision to construct a concentrating facility was made June 15, 1987 and construction started a week later. The facility, designed for 1900 tonne per day throughput, was ready for commissioning in September 1988. Outokumpu Engineering of Finland was chosen to prepare metallurgical flowsheets, select and develop plant layouts, and provide construction management. Kilborn (Toronto) contributed detailed engineering for civil, structural, mechanical and electrical components and outokumpu Equipment of Canada, the design, the supply, and commissioning of the instrumentation package. Hudson Bay undertook the initial metallurgical test work and preliminary design work."

Jan 1, 1990

By K. Ananthanarayanan, R. I. L. Guthrie, S. A. Argyropoulos

"The low cost and availability of micro-computers and their peripherals provides the metallurgical engineer with the opportunity to use such computers in a wide variety of applications. In this paper, the authors describe the development of a low cost data acquisition system capable of measuring up to 8 analogue channels at a sampling rate of up to 5000 measure mentsper second. This system is equipped with proper hardware and software so that the micro-computer can be linked to a central computer facility such as the McGill System for Interactive Computing (MUSIC). This central computer facility is supported by an AMDAHL V7 computer. Using the present interface, communication rates between the microcomputer and the central computing facility can be as high as 9600 (baud).The above mentioned data acquisition system is currently used for monitoring dissolution kinetics of ferro-alloy additions in liquid steel. In addition to this, special software has been developed which enables the user of this system to monitor solidification rates of ingots, etc. As economic considerations are always important, comparisons have been made with existing recorders which show that the cost Of the present system is only 30 per cent more than a two-pen strip chart recorder.RESUMELa disponibilité et le bas prix des micro-ordinateurs et de leurs périphériques permet à l'ingénieur métallurgiste d'utiliser de tels ordinateurs pour diverses applications. Dans ce rapport, les auteurs décrivent le développement d'un système d bas prix pour l'acquisition des données, capable de mesurer jusqu'à huit canaux analogues jusqu’à une vitesse de 5000 mesures par seconde. Ce système est équipe avec son propre ""hardware"" et ""Software"" qui relient le micro-ordinateur d’un ordinateur central, comme le système de McGill pour computations réciproques (MUSIC). Ce central d'ordinateurs est soutenu par l'ordinateur AMDAHL V7. Utilisant cet "" interface"", la vitesse de communication entre Ie micro-ordinateur et l'ordinateur central peut atteindre jusqu'd 9600 (baud)."

Jan 1, 1980

By Chris Cross

A working group from Anglo American, BHP Billiton, Rio Tinto and Xstrata reviewed supply and demand for graduates from mining education departments in countries where they normally recruit: Australia, Canada, Chile, Western Europe, South Africa and USA. Departments are typically small and increasingly unsustainable, resulting in a steady rate of closure. Supply and demand for graduates in the minerals industry is cyclical, with supply lagging behind demand and trending downwards. Currently, supply is tight and the industry is trying to expand with an ageing workforce. Greater collaboration between universities and within the industry is recommended to address these issues.

May 1, 2006

By J. R. Goode

"The Las Cristinas deposit in Venezuela contains reserves of 12.8 million ounces of gold at a grade of 1.20 g/t (Crystallex, 2004). The deposit comprises fully oxidized saprolite (SAPO) overlying a layer of sulphide-enriched saprolite (SAPS) which lies above carbonateleached bedrock (CLB) and carbonate stable or un-leached bedrock (CSB). Gold occurs at about the same concentration in all lithological groups. The bedrock units contain minor amounts of copper (about 0.1%) as chalcopyrite, while SAPO contains virtually no copper which has been leached and deposited in the SAPS zone.A previous owner began investigation of the Las Cristinas deposit in 1991. Over the next seven years, the company drilled 1,174 holes with a total length of 159 km, conducted extensive metallurgical testwork, including pilot plant operations, and completed feasibility studies. Construction was started in 1997 and again in 1999, however, on each occasion was suspended.Crystallex has been producing gold inVenezuela since the early 1990s. In 1997, Crystallex acquired Inversora Mael which had held two of the claims to the Las Cristinas concessions since 1986. In September 2002, Crystallex entered into a definitive agreement with the Corporación Venezolana de Guayana (CVG) to develop the Las Cristinas deposit.An extensive program of studies and testwork was started in late 2002 to determine an optimum development plan for Las Cristinas. Mine Development Associates, SNC–Lavalin Engineers and Constructors, SGS Lakefield Research Limited, J.R. Goode and Associates, and A. Laplante at McGill University acted as the main contractors.Because of the potential value of by-product copper, earlier flowsheets used carbon-inleach for SAPO, but processed all other ore types by flotation to produce a gold-copper concentrate with cyanide leaching of cleaner tailings to maximize gold recovery. Cyanide recovery was necessitated by the high copper content of the leach feed. Initial studies of available data by Crystallex revealed that direct leaching of all ore types would provide about 11% more gold recovery than the previously selected flotation route with reduced capital and operating costs.Bench and pilot-scale studies have confirmed that a SAG-ball mill-gravity-CIL route is very effective for all ore types and will give about 89% gold recovery. This paper describes the testwork conducted in 2003, discusses a 20,000 t/d plant design, and presents economic data."

Jan 1, 2005

Over the last three decades, the mining industry has been moving towards more underground mechanized mining methods and the number of LHD vehicles utilised has increased. The growth of mechanization and automation has benefited both workers and the mining companies. However, due to the design of the LHD vehicle and the limitations of the operating environment, restrictions to operator visibility are inevitable. The inability of the equipment operator to see clearly (i.e. people, objects or hazards) around the machine has contributed to a number of accidents including fatal injuries. In order to identify vehicle design characteristics resulting in restricted and blocked sightlines, visibility assessments for existing machines are traditionally completed in the field using a light filament technique. Past researchers have used the light filament technique to collect obscuration zones around the equipment and to produce a 2D chart of this information. The 2D shadow diagrams have proved to be useful in highlighting potential equipment problems and have been performed repeatedly to show the potential of redesigning a part of the LHD for improving visibility. The light filament method involves manually collecting data and requires a level of judgment to be used. As a result the method is susceptible to errors and requires around three hours to complete. The objective of the current research is twofold; firstly to develop a rapid method for field visibility data collection using a laser scanner and secondly to compare results of repeat tests for both light filament and laser scanning methods. A MENSI GS100 laser scanner along with Pointscape and 3Dipsos software has been used to collect visibility information and process the data. The research aims to develop the laser scanner as a technique to rapidly evaluate the visibility profile of an LHD vehicle. Machine design changes can then be assessed quickly using these results.

May 1, 2004

By W. N. Hamilton

As a result of a test-drilling program conducted by the Research Council of Alberta in 1968, a gypsum deposit averaging 30 feet in thickness, with a chemical purity of 84 per cent gypsum, has been proven to underlie the Clearwater River valley for a distance of 18 miles at depths ranging from near-surface to 300 feet. This and other subsurface deposits in the vicinity of Fort McMurray, Alberta are the product of local hydration of anhydrite beds believed to be the water-insoluble remains of the leached Prairie Evaporite formation of Middle Devonian age, the thick salt section of which is preserved down dip. The effects of salt solution are seen in the disturbed bedding and the intermixture of greyish green shale with gypsum in the core, the shale content being responsible for the rather low chemical purity of the deposit. A similar gypsum deposit, but probably of higher purity, is postulated to occur beneath the Athabasca River valley about 60 miles north of Fort McMurray.

Jan 1, 1969

By Barrie Robb

Outline 1. Mackenzie Aboriginal Corporation (MAC) 2. ACR background 3. ?Learning from Experience? project - What - Why - lessons 3. How Industry could contribute to sustainable Aboriginal communities 4. Concluding words What is the Mackenzie Aboriginal Corporation (MAC)? ? Aboriginal owned ? Established construction capabilities ? Commitment to development of northern resources ? Partners have extensive experience

May 1, 2008

By Andrew R. Marchbank

The application of biologically assisted methods for metal extraction in the mining industry has a long history, but development of modern techniques has been relatively slow. There is, however, a resurgence of interest in the industry with the recent development of methods to successfully treat base metals concentrates. Two major pilot plant programs for treatment of chalcopyrite concentrates have been initiated in the past year and results from one are beginning to be released. This paper provides an overview of methods that have been applied in the past; from the earliest deliberate applications of the technology, through the copper and uranium heap and dump leach applications, the more highly engineered agitated tank leach gold applications and the developments currently taking place in the industry.

May 1, 2002

By D. Fleury

"This paper describes the challenges of mining a sill pillar under various types of paste backfill quality. From 1994 to 2002, Louvicourt mine produced approximately 12,600,000 t grading 3.5% Cu, 1.5% Zn, 27 g/mt Ag, and 0.85 g/mt Au. The mining method is transverse blasthole stoping, mining primary and secondary stopes. The production of this 4,300 t/d operation was accomplished using two mining horizons; from the 655 m level to the 415 m level and from the 860 m level to the 680 m level. The main sill pillar is between the 680 m level and the 655 m level. The second sill pillar is between the 885 m level and the 860 m level representing a quarter of the main sill pillar in size. Since 2002, production has gradually decreased and mining activities are expected to end in mid-2005. The sill pillar production will represent almost 25% of the total mine production. The overall recovery of the sill pillars stopes will be discussed in this paper. To recover the sill pillars, more than 1,500 m of development was planned in or under paste backfill. The first sill pillar stopes under paste backfill were mined out in 2002 with excellent results."

Jan 1, 2005

By C. O. Aksoy

There is a long history of coal production in Turkey with electric energy generated from power plants since the 1950s. However, the cost of power generation is high. Therefore, it has become necessary to find a means of decreasing production costs to become more competitive in a global market. This paper attempts to economically minimize the overall operating costs of a dragline-shovel-truck system applied at an open pit mine that has fed the Yatagan power plant since 1979, lowering the lignite production cost, and indirectly, the overall electricity generation unit cost. Systems currently in place, as a result of former optimization studies, are time-consuming and expensive to re-implement to comply with today’s very different geometric and economic conditions affecting mining operations. In such cases, rather than re-optimization, it is more viable to identify the parameters that affect the minimum unit cost, via a cost minimization study, allowing present mine equipment to be utilized more efficiently. Unit cost minimization analyses are subject to the capacity of the pool of mining equipment available, combined with the mining block geometry from pre-stripping onwards. In this overall unit cost minimization study, P&H shovels and CAT 777 trucks with capacities of 15 yd3 and 77 tons, respectively, were used in truck-shovel pre-stripping operations. A 65 yd3 Marion 8050 dragline was used to expose the overburden immediately over the coal seam. Pre-stripping bench heights varied from 8 m to 20 m and dragline bench heights from 20 m and 25 m were evaluated to minimize the unit cost of field operations. Total overburden extended to a depth of 60 m (35 m to 40 m for pre-stripping). Minimization analyses performed on the pre-stripping truck-shovel operation, prior to dragline operations, determined that the shovel bench height should be 15 m requiring a dragline bench height of 25 m.

Jan 1, 2005

By Christian Bourcier

La méthode d?exploitation traditionnelle de la mine est le chantier chambre-magasin. Cependant, lors de l?exploitation d?un chantier, nous avons été confrontés à un problème de soutirage. Le minerai abattu est resté accroché à l?intérieur du chantier ce qui nous obligea à soutirer environ 200 wagons, représentant 700 tonnes. Suite à l?ampleur de la situation, nous avons décidé de finir l?exploitation du chantier par la méthode sous-niveau long trou retraité. Cette première expérience de récupération de piliers ayant été réalisée avec succès, nous avons décidé de continuer avec deux autres récupérations de piliers afin de pouvoir augmenter notre expertise autant au niveau technique qu?au niveau économique.

Oct 1, 2001

By Kathryn L. Neale, Derek L. Mulligan, Robin E. Goad, Norman A. Duke, A. Hamid Mumin, W. John Camier

"Abstract - The NICO and Sue-Dianne deposits are being explored and delineated by Fortune Minerals Limited in the Mazenod Lake District of the Northwest Territories, using an Olympic Dam model. The deposits were discovered in the south part of the Great Bear magmatic zone (GBMZ) within the Proterozoic, Bear Structural Province of the Canadian Shield. They are the only known significant Canadian examples of Proterozoic iron oxide-hosted polymetallic deposits. Worldwide, this class includes such deposits as Olympic Dam and Ernest Henry in Australia, Kiruna-Aitik in Sweden, and Salobo in Brazil. Their considerable size, up to 2 billion tonnes, and polymetallic ore assemblages make them highly attractive targets for exploration. Common characteristics of this class include their Early to Middle Proterozoic cratonic settings with extensional rifting evolving from collisional tectonics. Deposits typically occur along major structural lineaments within the aureoles of a distinctive suite of anorogenic potassium-rich "A-type" granite intrusions. Although hosted by diverse lithologies, deposits of this class are characterized by a number of other diagnostic regional- and deposit-scale features, which may be recognized in reconnaissance- and propertyscale geological and geophysical surveys.The southern GBMZ in Canada has several characteristics (age, tectonic setting, geology and geophysical attributes) similar to those of the Olympic Dam deposit and its other significant global analogues. Airborne and ground geophysical surveys carried out in the GBMZ identified coincident potassium, uranium, magnetic, resistivity, chargeability, and gravity anomalies centered over the NICO deposit. The nearby Sue-Dianne deposit is characterized by coincident uranium, potassium, magnetic, resistivity and chargeability anomalies. Both deposits occur within a regional, northweststriking, arcuate trend of volcanic and sedimentary rocks characterized by significant positive Bouguer-gravity and magnetic responses and are believed to represent a major basement discontinuity. The NICO anomalies are at the intersection of this regional trend with a major transverse fault through Lou Lake. Regional and local geophysical data indicate the presence of significant concentrations of iron oxide within a broad area of intense potassium metasomatism. Geological mapping identified cobalt, gold, bismuth, and copper mineralization in biotite-magnetite-amphibole-sulfiderich ironstone and schist. This mineralization is localized within altered wackes of the Snare Group, which are unconformably overlain by potassium feldspar- (±hematite ±magnetite) altered rhyolite of the Faber Group. The Sue-Dianne deposit is a hematite-magnetite-Fe-silicate-cemented diatreme complex enriched in copper, silver, gold, and uranium within a broad zone of potassium, iron, quartz, and epidote metasomatism. The diatreme is located at the intersection of two major faults at the north end of the basement discontinuity and is hosted in rhyodacite ignimbrite marginal to the Faber Lake rapakivi-granite pluton. At both deposits, diatreme- and maar-facies iron oxide-cemented breccia straddle the regional metasedimentary-volcanic unconformity, suggesting that mineralization formed in a near-surface environment synchronous with the onset of volcanism."

Jan 1, 2000

By François Robert

The rate of new mineral discoveries in Canada has been declining in the last two decades. In response to the challenge and to stagnating investments in mining-related R&D, twenty Industry partners, supported by PDAC and Natural Resources Canada, established in 2010 the Exploration Innovation Consortium (EIC). This Consortium seeks to promote the discovery of new resources in Canada through coordination and sponsorship of industry-focused innovative and collaborative research and technology development, as well as training and education in mineral exploration. The two main themes of the integrated R&D program focus on exploration targeting in Deep and Mature Environments and in Remote and Covered Terranes.

May 1, 2011

By William Pitman

Ground instability and subsequent rock falls are a major concern in underground mines. As a result, several mining companies are conducting risk assessments of the ground support installed in their mines. Risk assessment is now commonly used to provide mine operators with a systematic process to assess the strategic risks that could lead to injury to personnel or loss of production, and evaluate possible risk control measures. Risk assessments can be carried out to identify major hazards, assess the likelihood of occurrence and consequences of each hazard and estimate the level of risk. This process allows assessment of possible remediation actions to minimize the risk and likelihood of occurrence or mitigation of the consequences to a level that is reasonable and practical. This paper presents two practical mine applications of qualitative risk assessment of ground support to highlight the benefits of this process. Yearly or bi-yearly risk assessment of mine excavations can assist mine operators in prioritizing resources and areas that require support remediation. In addition, it provides a mechanism for proactive response to reduce potential risks associated with personnel safety, equipment safety and environmental impact. It also provides a baseline against which changes in ground condition can be compared and quantified.

May 1, 2004

By Oyku Selimoglu

The key to successful mine production plan and subsequent operation is efficient mine layout design and optimization. Pit layout design and optimization allow the delineation and extraction of mineable reserves and the minimum waste subject to slope stability, economic, quality and quantity constraints. Many design and optimization software packages have been developed to aid this intensive and challenging process. These packages include VULCAN, SURPAC, DATAMINE, GEMCOM, MICROLYNX, MEDSYSTEM and MINESIGHT. These software packages are developed as integrated computer-aided systems used for database creation, survey, geological and geostatistical modeling, mine planning and production optimization and environmental modeling. In Turkey, many mining companies still plan and design mine layouts with traditional hand methods. In this study, VULCAN has been used to design and optimize the Eti-Bor A.S. Kestelek Boran Open Pit Mine in Western Turkey. The main objective is to show the company the superior advantages of mine planning software for designing and optimizing mine layouts over the traditional hand methods. Drill hole data used by the company to estimate the reserves for planning are used in this study. The ore grade varies between %1,04 B2O3 to %47,33 B2O3. The pit toe and crest strings are projected using variable batter angles and berm distances. On the north side, batter angle is 180 and berm distance is 25 meters, on the south side, batter angle is 320 and berm distance is 15 meters. In addition to that open pit bench height is 10 meter. The concepts of block modeling are applied to the Kestelek open pit mine with detailed ore grade modeling for each block. The Lerchs-Grossmann?s algorithm is used to optimize this mine based on the block model, the economic block values for each block and the underlying field constraints. The results from VULCAN were similar to the estimates by hand. The reserve estimates from VULCAN is 13,192,870 tons compared with the hand estimate of 13,200,000 tons, overburden estimates of 15,622,889 m3 compared with 15,000,000m3 obtained by hand with a stripping ratio 1.18:1 (m3:ton) from VULCAN versus 1.14:1 (m3:ton) from hand estimate. Vulcan improves the efficiency, speed and reproducibility of the planning results. It provides mining engineers, geologists and surveyors with a cost-effective modular system for assessing and planning the mine layouts. Furthermore, Vulcan?s specific modules allow efficient access and manipulation of databases, open pit mine design, block models, optimized 3D mine layouts, and more. However, for competitive business in Eastern Europe, VULCAN should improve its software support. Effective training, help desk support systems and nearby distributors with just-in-time solutions to company problems will generate competitive business for VULCAN.

May 1, 2007

By K. Mikulash

"Agnico-Eagle Mines Limited is located at Joutel in North-Western Québec. The mine is about four miles north-west from the town on the left bank of the Harricana River. The present mining is 1,800 feet deep with an extensive geological development below this level.HISTORY The development of the ore body started sometimes in 1967 and then the operation ceased in 1969 and again reopened in 1973 due to higher prices of gold. During these periods of active development, a considerable metallurgical research has been done by different laboratories and research and design companies.The original capacities of the Mill differed as much as 30%. So did the concept of the ore treatment. The original design of the mill was for 200 TPD of ore with straight cyanidation. The problems with low gold extraction, high reagent consumption and poor filtration resulted in a decrease of the expected mill output to an initial 550 TPD with gold recoveries in the order of 40 to 60%.Although the studies and research work done on the ore varied, all of them had a common conclusion: a very fine grind is needed to expose gold. The mining method (sub-level blast hole mining) now provides the ore that differs from that on which the metallurgical test work was conducted and the original capacity calculations had been done.These variations in the concept consequently led to the conclusion that the size of gold is a determining factor for the process.Kilborn Engineering provided the original design with the Leslie Eng¬ineering completing the design. The metallurgical test work has been done by the Department of Energy, Mines & Resources, Lakefield Research of Canada, Kilborn Engineering and Sidam Incorporated.The new flotation section with secondary grinding has been designed and put into operation by the company in December 1975 with the results yet to be evaluated."

Jan 1, 1976

By Fidelis T. Suorineni

The Ashanti mine, located in Obusai, Ghana, West Africa, has been in production for over 100 years, and is currently the second largest single gold producer in Africa. The mine covers a concession area of 434 square kilometers with four main ore types: the quartz vein type, disseminated sulphide type, supergene sulphides and transition ore, and granitoids stock works (visible gold and quartz veinlets). Various mining strategies and methods have been employed for the mining of the narrow-vein ore at Ashanti. In recent years, the mine owner: Ashanti Goldfields Company Ltd. has embarked on a mine-wide expansion program to boost production to a target of one million ounces per annum. With the rapid depletion of its high-grade ore, a suitable mining method was required to produce a high tonnage at low cost to meet production objectives. This paper discusses how the Ashanti mine applied Canada experiences in mining technology to boost production, and the impact that the differing geological settings between the two countries had on the stope performance at the Ashanti operations. Experience developed at the Ashanti mine led to innovative modifications for stope layout and design methods in relatively poor ground conditions.

Oct 1, 2001

By Adam Wright

"Les Mines Selbaie have been producing copper and zinc concentrates from the A-1 ore zone since 1986. This paper reviews major developments in flotation practice over that period. Firstly, ore blending strategies for Selbaie's non-homogeneous polymetallic ore are discussed. The evolution of reagent use is then reviewed, focussing on copper collector trials. A description of Selbaie's flotation columns follows. Finally, past and future developments for process control are outlined.Depuis 1986, Les Mines Selbaie produisent du concentré de cuivre et de zinc provenant de la zone A-1. Cette conférence présente !es développements majeurs en flottation qui ont eu lieu depuis ce temps. Premièrement, la stratégie du mélange de minerai non homogène polymétallique est présentée. L'évolution des réactifs utilises est démontrée, particulièrement !es collecteurs de cuivre. Par la suite !es colonnes de flottation sont presénteés et finalement !es développements futurs ainsi que ceux qui ont eu lieu dans le contrille de procédé sont expliqués.1.0 INTRODUCTIONLes Mines Selbaie, wholly owned by Billiton Metals Canada Inc., is currently mining and processing ore from a polymetallic surface deposit located 288 km northwest of Val D'or, Quebec (fig. 1). The mine produces copper concentrates containing gold and silver as well as zinc concentrates containing silver. 8000 dmt/day of ore is crushed and ground to 80% passing 49 µm, prior to processing by conventional copper/zinc differential flotation. The flotation circuits consist of both conventional and column cells (fig. 2). Detailed descriptions of the mill are available elsewhere in the literature (8,9)."

Jan 1, 1995