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By J. A. Stewart

"A common problem in the mining industry involves the overloading of established conveyor systems. This overloading can have a number of causes, such as new production technology or a changing market condition which increases demand. An overloaded system usually spells disaster and leads to clean-up problems, equipment failures and lost production. The Cape Breton Development Corporation's Lingan Mine had a serious overloading situation on its underground coal clearance system, and equipment was being damaged and production was being lost. It was rectified, in part, by increasing the coal clearance capacity through the use of booster conveyors. This paper discusses the problems which led to this situation, the booster concept and the installation of the first unit at the Lingan Mine.IntroductionThe Lingan Mine is a submarine coal mining operation with an annual production of 1.5 million tonnes from three advancing longwalls. Coal is conveyed 3400m up a 13% slope to the surface. Designed and installed in the early 1970s, the system's 820-tonne/hour design initially proved adequate; however, by the late 1970sthe system was handling surge loads of 1640 tonnes per hour due to the introduction of new face equipment.The coal clearance system consisted of three 485-Kw, two 210-Kw and one 105-Kw conveyors. Each conveyor was designed for 820 tonnes per hour using 1050-mm, Type 10 belt with a 35-degree troughing profile.There were many effects of the overloading on the system:• Loading beyond the physical capacity of the belt resulted in spillage along the conveyor, which increased operational and maintenance costs.• Overloading of the drive components resulted in premature equipment failures.• Spillage at the drive pulley often resulted in damage to the belt and pulley lagging and, under extreme conditions, the conveyor would require partial unloading before it would operate. This was a particular problem under wet conditions because the 485-Kw conveyor drives were fitted with single-drive drums."

Jan 1, 1982

By Daniel Hodouin, Claude Bazin

"This paper examines the economic advantages of tuning the operation of a differential Cu-Zn flotation circuit as a function of metal prices. Three operating strategies are considered in the analysis: 1) the operation of the circuit at planned copper and zinc concentrates grade with maximum recovery of both metals; 2) the operation of the Cu circuit at maximum copper smelter return per ton of ore and of the Zn circuit at a maximum zinc smelter return per ton of ore; and 3) the operation of the circuit at maximum copper and zinc smelter return per ton of ore. The second strategy tunes the copper circuit independently from the zinc circuit, while the third strategy tunes both circuits simultaneously IntroductionMetal prices play a very important role in the mineral industry (Malhotra and Dowling, 1991). In many cases, metal prices can be the basis for the GO/NO GO decision of a mining project (Malhotra and Dowling, 1991; Apostolides, 1983; Davis, 1996). This direct impact of metal prices on company revenues is highlighted in many annual reports. The 1995 Noranda Annual Report indicates that a variation of 10% of the copper price impacts its yearly revenues by $25,000,000. Some mine operators claim to mine stopes as a function of metal prices (Liimatainen, 1996; Hartman, 1992). This impact of metal prices is also recognized by mill operators that seek strategies to tune ore processing circuits to maximize revenues from the concentrate they sell to smelters (McKee, 1991; Barker et al., 1989; Hales and Ynchausti, 1994; Cipriano et al., 1995). In many cases the problem of tuning the operation of an ore processing circuit is complicated by the fact that the ore contains two or more valuable metals which have to be recovered into separate products. The Agnico-Eagle (Robitaille and Cousin, 1995) and Barrick East Malartic (Pelletier, 1996) Cu-Au mines are examples, as well as the Cu-Pb-Zn Brunswick mine (Shannon et al., 1993) or the Cu-Zn Louvicourt (Whiteway, 1995) and Selbaie (Wright, 1995) mines."

Jan 1, 2000

By J. Parreira

This paper presents a deterministic/stochastic model that was created to compare an autonomous haulage truck system to a manual one by calculating and estimating benchmarked Key Performance Indicators (KPIs) such as productivity, safety, breakdown frequencies, maintenance costs, labour costs, fuel consumption, tire wear, and haulage cycle times.

Aug 1, 2013

By M. J. Fairweather, Keith Lee, Naseem Mian

"The initial metallurgical response of the lead flotation circuit at Cominco Alaska's Red Dog Mine was substantially below feasibility expectations. A program of diagnostic mineralogical analysis pointed the way to a number of process improvements, including simplification of the flow sheet and installation of a large flotation column as a lead cleaner. A diagnostic mineralogical analysis of the improved circuit shows that inadvertent activation of both sphalerite and pyrite has been substantially reduced, resulting in significant improvements in metallurgical performance. Directions for further improvements to the circuit performance are suggested by the recent analysis.IntroductionRed Dog is a high-grade, sedimentary exhalative (sedex) deposit with relatively simple mineralogy. The primary non-sulphide gangue minerals are quartz and barite, with minor barium carbonate (witherite). The iron sulphate minerals, siderotil, rosenite and copiapite occur variably throughout the deposit. Mineral texture is variable ranging from liberated sphalerite grains visible to the naked eye to intergrowths, particularly between sphalerite and galena, to less than ten microns. Both pyrite and marcasite are present. To date no enhanced reactivity of marcasite has been observed. For this discussion, ""pyrite"" will be used to refer to both iron sulphide minerals. In common with other sedex deposits, Red Dog contains organic and sulphur impurities."

Jan 1, 1997

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 F. M. Makarinsky

"SynopsisThe Kanichee open pit mine and milling complex is situated approximately four air miles north-west of Ternagami, Northern Ontario, in Strathy Township. Mining and milling production commenced in January 1974.Milling throughput currently is at a rated capacity of 500 tons per day, seven days per week. A bulk nickel-copper sulphide concentrate is produced, and is trucked daily to the smelter at Falconbridge Nickel Mines Limited, Falconbridge, Ontario, some 120 road miles from Kanichee. Concentrate grades produced are in the order of 4.0% Ni and 8.0% Cu, with corresponding recoveries of 68-70% nickel and 86-90% copper. Stage additions of 100% guar-gurn solution reagent to the flotation cells for depression of talcose minerals, proved to be the major break-through for optimizing metallurgical performance.2. HistoryThe present Kanichee Mining property is known to old-timers in the Temagami area as the former Cuniptau Mine. Several attempts were made in the mid '30's and 40's to extract the ore at a profit, but each effort resulted in failure.In 1933-36, Cuniptau Mines Development Co. Limited, later called Cuniptau Mines Limited, sank a 245-foot vertical shaft and completed 2,200 feet of lateral work on the 100-140 and the 225 foot levels. Fifteen tons of ore were sent for testwork to the Mines Branch, Ottawa, Ontario.Cuniptau Mines Limited, in 1936, milled some 3,000 tons, and the resulting concentrate was put through a pilot smelter situated on the present mine site. Metallurgically, the smelting results were not encouraging, primarily due to the high melting point of the talcose minerals in the concentrate. From the period 1937-48, minor exploration work was done by Ontario Mining Corporation, Ontario Nickel Mines Limited, and Trebor Mines Limited. During the period 1948-49, 128 diamond drill holes, totalling 40,900 feet were evaluated by Trebor Mines Limited. In 1961, the name was changed to Ajax Minerals Limited, during 1968, five diamond drill holes were sunk, totalling 1,700 feet. Since that period the property has remained idle."

Jan 1, 1975

By W. D. Haley

The report of the Forestry Committee, presented to the recent Imperial Conference at London, is discouraging in its view of the future of timber resources and supplies. From a review of the forestry situation throughout the world, there is every likelihood that, thirty years from this, a shortage of the soft-woods will be severely felt. In the United States, only about one-third of the present forest area contains virgin timber. This will be cleared at the rate of five and a half million acres a year, so that in twenty-five years it will be about all gone. Canada has only about 27 per cent of her original forests left, and her virgin soft-wood will last but another half century. At the present time, the value of her lumber products is over $300,000,000 annually. During the summers of 1909 and 1910, the Government of Nova Scotia caused an examination to be made of the forest conditions in this Province. The reconnaissance, which was under the direction of Professor B. E. Fernow, of Toronto, involved an examination of the various soils, the rate of growth of the wood, and a general survey of the forest area. The importance to the Province of conserving its forest resources was clearly shown, and a number of recommendations were made, which; however, were never acted upon.

Jan 1, 1927

Located in Timmins, Ontario the Porcupine Joint Venture, a pooling of assets between two existing operations (the Dome Operation of Placer Dome (CLA) and the Hoyle Pond Operation of Kinross Gold Corporation) came about on July 1st, 2002; Placer being the manager of the Joint Venture with 51% ownership and Kinross with 49%. The formation of the Joint Venture was the realization of the dream of many who could envision the benefits of the whole area being operated as one entity ? the combination of the majority of assets in the Porcupine Camp into one venture containing tremendous synergistic potential of manpower, infrastructure, land tenure and exploration development. The name Porcupine in the gold mining industry brings with it the legacy of world class gold mines; the Hollinger, McIntyre and Dome with a proud tradition of excellence. The name Porcupine brings with it the legacy of over twenty individual mining companies in operation at any one time, producing over 65 million ounces of gold.

May 1, 2003

By Manish Kumar Jain

The mineral industry in India is an important contributor to the country?s GDP and foreign trade, and also a significant source of employment generation. The industry is distributed almost all across the country and has operations in some of the remotest areas, where it has also served as a sole source of infrastructure development. India produces 89 minerals, out of which four are fuel minerals, 11 metallic, 52 non-metallic and 22 minor minerals. The mining leases are occupying about 0.21% of the total land mass of the country. Indian mining industry is characterized by a large number of small operational mines (approx 3000 mines). Appropriate systems have been put in place to ensure sustainable growth of the sector, which include formulation of procedures for scientific prospecting and mining and development of a mechanism of prior environmental and forest clearances for mining projects. Main emphasis is to protect the health and safety of mine workers, as well as to safeguard the interests of indigenous people through rehabilitation and resettlement packages. Efforts are under way to mainstream the artisanal and small-scale mining sector in order to promote equity in the mining industry. The issue of scientific closure and reclamation of the abandoned mine sites poses a major challenge. Present paper illustrated several initiatives have been taken in this direction along with case studies, which could be replicated in other parts of the country.

Aug 1, 2013

By Guangyuan Li

A 3-D block-spring model (BSM) has been developed for simulating the behaviour of jointed rocks. The model uses a discontinuous formulation and an iterative procedure to solve the large displacements in jointed and faulted rock masses. The 3-D BSM has been used to simulate mining excavations in jointed rocks around an open pit and underground settings. The applications have demonstrated that it is a practical tool to solve complicated problems of rock mechanics in civil and mining engineering. This model has recently been modified to incorporate complex geological conditions, such as underground water flow (seepage), unstable blocks and the time-dependent behavior of backfill materials. To demonstrate the capability of the 3-D model this paper presents the fundamentals of the 3- D BSM and its application for open-pit mining. A complete computer package BSM3D has been developed based on the 3-D block-spring model. The package consists of a solving engine for numerical analysis and a Windows based processor for mesh generation and results display. The multi-functioned pre-processor provides tools and menus to help users setting up models easily and conveniently. The fully featured post-processor allows users to view the results in different windows and orientations. The graphical results include contours, vectors, animation of rock movement, and the failure state of the rock structures.

May 1, 2001

By R. V. Ramani

"A computer simulation model of a dragline has beer developed for the study of alternative dragline deployment schemes for varying geological and mining conditions. In this paper, the mathematical aspects of the model, the input data and output results are discussed. An application of the model to a coal mine in eastern Kentucky is presented.IntroductionDraglines are very productive machines. To extend their operating ranges, they are operated in several modes such as advance benching, key cut, extended benching and pullback. Unfortunately, these variations result in low machine productivities. Appropriate methods to operate these machines must be developed on the basis of detailed analyses of dragline performance under varying geological and mining conditions. There are several standard engineering procedures for the selection of dragline, and design of a dragline pit (Ramani, Iroegbu and Manula, 1976). However, the complex interrelationship which exists among equipment, methods and natural conditions can be quantified only through orderly and systematic experiments.Computer simulation is well suited to studying these types of equipment selection and method layout problems. Several alternatives can be analyzed in a relatively short time by the modification of input variables. Also, the application of computer simulation models can significantly reduce the manpower and cost required for such analysis."

Jan 1, 1985

By A. J. MacRae

Metallurgical furnaces are made up of complex multi-component systems that must function either together or in parallel for safe, and reliable operation. Thermal expansion of single material components experience induced stresses during heating and cooling, which can lead to cracking or failure. Multi component elements and systems can experience significant thermally induced stresses during both steady state and transient temperature conditions. Examples pertaining to temperature effects on refractory, copper cooling blocks, furnace shells, and complete systems will be discussed. The purpose of the paper is to highlight how stresses and strains are developed due to differential thermal expansion.

Jan 1, 2015

By Steve Cole

"The economic and strategic importance of PGE bearing deposits is fuelling renewed exploration and development efforts in the precious metals mining sector.This paper presents a review of the various techniques used in the processing of PGE bearing ores, from primary benificiation to processing routes for the different flowsheets that have been developed amongst current producers. Recent innovations such as preconcentration of ore using gravity separation, recent trends in flotation circuit design and the development of hydrometallurgical routes for the direct treatment of flotation concentrates without the need for smelting will be discussed. Data from recent projects will be presented to illustrate common characteristics of PGE ores and concentrates.INTRODUCTIONThe six platinum-group elements (PGE): ruthenium, rhodium, palladium, osmium, iridium and platinum, together with gold and silver, are considered to be ""precious"" metals. The recent spike in platinum and palladium prices coupled with the projected increase in demand for the metals has fuelled a spate of exploration and new projects in the PGE sector. Historically primary producers of PGE metals have controlled the flow of information relating to the mining and processing of these ores into the public domain. Very little published information relating to individual operations and processes is available in comparison to the abundant literature relating to other metals.The purpose of this paper is to provide a general overview of the issues relating to the processing of PGE ores. Each topic discussed could easily be the topic of a paper or book and so in many cases only the surface of the topic will be scratched. An attempt has therefore been made to provide as many references as possible.This paper discusses the classification and location of PGE ores, the mineralogical factors that affect recovery of PGE's, methods currently used for recovering PGE's and process trends in PGE metallurgy."

Jan 1, 2002

By S. Dessureault, J. Porter, M. Woodhall

Information and communication technology (ICT) is seen as a key source of future productivity improvements in mines. The information technology infrastructure (ITI) necessary to achieve these productivity improvements will come in the form of data integrated from multiple source systems throughout the mining value chain. Two pure approaches are available: supplier-controlled or operations controlled data structures; each strategy has its own advantages and disadvantages. Case studies involving the South African mining industry are used to demonstrate the advantages of using hybrid-controlled data structures. Depending on the level of operational control, new skills are also necessary to be learnt by mining professionals including: information engineering; creating consistent and quality data; and process improvement techniques that use the integrated data for improving the operation.

Jan 1, 2004

By Stuart McTavish

"Noranda's Goldstream mine is a 1,500 ton per day copper-zinc mine located 60 miles north of Revelstoke, B.C.The orebody which contains 3.69% Cu and 2.69% Zn was discovered in 1972. Construction of the mine and mill was completed in 1982 and start up was achieved in May 1983.This paper will describe the flowsheet and related equipment 1n the crusher and mill, in particular the dewatering section where two Larox pressure filters are used to dry the concentrates.INTRODUCTIONThe Goldstrean property is located 60 miles north of Revelstoke, B.C. in the Goldstream River Valley (Figure #1). It was discovered during the construction of a logging road in 1972. Exploratory drilling was initiated in 1975, and in 1976 a portal was collared to obtain underground data. Samples were taken from the underground workings for metallurgical bench tests and a pilot plant run.Due to economic conditions, the decision to go into production was delayed until 1980. Concentrator construction and underground development progressed simultaneously during 1981 and 1982, and were completed by the end of 1982. Start up of the concentrator was achieved on May 2, 1983.The ore typically contains about 40% sulphides, which are chalcopyrite 10%, sphaletite 6%, pyrrhotite 20%, and pyrite less than 5%. The sulphide minerals have a high degree of intergrowth. Most of the sphalerite occurs in micron sized grains which are embedded in the pyrrhotite and, to a lesser degree in the chalcopyrite. There is also some fine dissemination of the chalcopyrite in the pyrrhotite. The waste rock is made up of about 30% quartz, 20% guange silicates, and 10% carbonates. The ore has a specific gravity of 3.2 and a natural pH of 8.2."

Jan 1, 1985

By Charles "Chick" Rodgers

"The Key Lake uranium mine is the largest single uranium producer in the world. It is owned 2/3 by Cameco Corporation and 1/3 by Uranerz Exploration and Mining. Cameco is the operator. Current production is fourteen million pounds per year of uranium oxide (U308).The mine's location is 570 kilometres north of Saskatoon on the southern edge of the Athabasca Basin approximately at latitude 57° 11 'north and longitude 105° 34' west. Access to the mine is by an all-weather road and a private airstrip.The mill was commissioned in 1983. A molybdenum plant was constructed in 1989 in response to increasing molybdenum content in the yellowcake or final product. Early test work had showed that the first ore body to be mined, the Gaertner deposit, would present few problems with regards to molybdenum in the product. However, the test work also showed that the higher molybdenum content of the Deilmann ore, the second Key Lake orebody to be mined, would result in increased molybdenum concentrations. Without the molybdenum plant, penalties would become excessive and some product might not accepted by the refineries.This paper will describe the current Key Lake mill process with emphasis on the molybdenum solvent extraction process. It will cover the chemistry of the process, process development in the mid 1980's, and current operating practices.The Key Lake milling process consists of five individual plants, crushing and grinding, leaching -counter current decantation (CCD), solvent extraction, yellowcake/crystallization and bulk neutralization (Figure 1. Simplified Mill Flowsheet). A detailed mill flowsheet can be found in the appendix."

Jan 1, 1996

By Jessica Egan, Daniel Hodouin, Mohammed Reza Khalezi, Steve Bellec, Claude Bazin, Carl Duchesne

"A model for gold leaching was developed and implemented into a simulator. The simulator uses a description of the ore that is based on the mineral composition and precious metal content. The model accounts for the distribution of minerals and precious metals through the size intervals. An ore texture model based on precious metals and minerals grain sizes within the ore is used to predict the exposed surface of the species in the various size intervals. A model is proposed to predict the rate of dissolution of any species dissolution using the exposed surface, particle size, cyanide and oxygen concentrations, temperature, pH and agitation. The flow of slurry through a leaching tank is modelled using a parallel arrangement of perfect mixers to simulate a bypass and a Cholette-Cloutier mixer model. The simulator can be used for circuit optimization but was developed to provide an environment for learning the basic concepts of process analysis methods. Examples are given to illustrate the application of the simulator for planning tracer tests and sampling campaigns.INTRODUCTIONThe constant pressure to improve the operation of processes that are already close to optimum imposes to plant engineers to be aware of the available process analysis tools and to be able to use them to assess process operation and make a diagnosis to possible problems. Some of these tools are:•,Sampling the streams of a process;•,Data reconciliation;•,Analysis of mixing in reactors;•,Estimation of rate parameters;•,Optimal tuning and flow sheet modification;•,Automatic control and real time optimization.Although some of these tools are part of the curriculum of many university engineering programs, the students are not exposed to actual process analysis problems. In addition the complexity of the ore dressing processes compounded with unavoidable measurement errors and plant disturbances can discourage many motivated engineers. These factors often lead to an incomplete valorization of the collected data and a poor return on the investment associated with the sampling, testing and analysis of the samples.Simulators are readily available for process optimization (Yalcin and Shang, 2006) by allowing:•,The simulation of various flow sheet configurations;•,The simulation of a change of operating conditions;•,The simulation of various control strategies;•,The training of plant operators.However few simulators have been developed with the objective of providing an environment for training plant engineers and technicians to the use of tools for process analysis and optimisation."

Jan 1, 2008

By H. J. McQueen

Before 1950, hot working was simply deforming above the recrystallization point and gave a soft product compared to cold working. From 1960 onwards, improved testing in compression and torsion (stress, strain rate, temperature, quenching) provided valid specimens for microstructural analysis by polarized optical and transmission electron microscopy (TEM). Indeed, TEM was essential to uncovering the hot working mechanisms because it could distinguish between cold and hot substructures (dynamic recovery) in either initial or new grains (dynamic recrystallization). Over the years, teams at Concordia, McGill and UBC obtained NSERC support for students and equipment. CANMET built up a hot forming group having capabilities from high-rate cam-plastometer compression to rolling of experimental alloy billets; this was combined with latest metallographic instruments for fundamental research. Al alloys of every class (2000, 3000, 5000, 7000, 8000) were studied to understand the effects of solutes, precipitates, dispersoids and composites. The complex flow patterns in extrusion were clarified and modeled by finite element methods. Physical simulations of rolling schedules (up to 20 passes and reductions of 98%) by torsion provided evidence of microstructure development during both the passes and the softening intervals, thus clarifying development of texture in different alloys. The results frequently appeared in proceedings of Light Metals symposia and Canadian Metallurgical Quarterly

Jan 1, 2011

By Graham Walker

A new Code of Practice for the brake performance of off -highway vehicles was established in Alberta in 1976. Vehicles loaded to gross vehicle weight must be capable of stopping with mechanical brakes five times in quick succession on a grade of 10 per cent from a speed of 28 miles per hour. Comparative trials of various brake systems have been carried out and some combinations capable of meeting the Code are identified. Some problem areas in truck braking are reviewed and potential developments indicated.

Jan 1, 1977

By Vincent Roy

Numerous on going activities at the Daniel-Johnson Dam : ? Surveillance / monitoring ; ? Structural investigations & evaluation ; ? Injection work ; ? Crack mapping ; ? Instrumentation management (drawings & inventory) ; ? Drainage system state ; ? Foundation evaluation

Aug 1, 2013