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By Claude Gosselin

En 1995, la Compagnie minière Québec Cartier a mis de l'avant un projet de recherche sur la modélisation de l'écoulement des gaz pour ses fours de frittage à l'usine de bouletage de Port-Cartier. Cette démarche s'inscrivait dans un large processus de collaboration avec l'Université Laval et le Consortium de Recherche Minérale (COREM). L'usine de bouletage possède deux fours de frittage d'une capacité moyenne de 600 tonnes/heure pour chacun des fours. Les fours de frittage sont des systèmes complexes d'échange de chaleur qui fonctionnent à contre-courant (le débit de boulettes versus les débits de gaz). Pour rencontrer les spécifications reliées aux propriétés mécaniques des boulettes, le processus de fabrication requiert des mesures et un contrôle des systèmes très précis. L'information fournie par plus de 70 capteurs (pression, température, puissance, vitesse, hauteur de lit, position de volet....) est utilisée pour manipuler une vitesse de grille, cinq ventilateurs et neuf zones de brûleurs. Malheureusement, les variables qui influencent fortement les mécanismes de frittage, c'est-à-dire les débits de gaz dans les différentes zones du four ainsi que la masse de boulettes qui circulent ne sont pas mesurées. Une méthode est donc proposée pour une estimation en ligne de ces variables. La méthode est basée sur un arrangement de 65 équations reliant pressions, températures et débits de gaz dans les conduites, les ventilateurs, les sections du lit et les fuites (Gosselin, 1998). Pour des raisons de simplification de cet article, seul un sous-système du four sera présenté. Les techniques de réconciliation des données reliées à la conservation de la matière et de l'énergie montrent que la mesure en ligne du débit de boulettes mène à l'estimation des débits de gaz et apporte des avantages intéressants pour le contrôle des variables stratégiques des fours.

May 1, 2001

By M. A. EI Zeky, A. E. El-Nikbaily, M. A. Shahin

"Possible mechanisms of microsilica dust formation and factors affecting its quantity have been discussed. General mathematical models to predict the dust quantity based on electrical and coke consumptions, and flue gas temperature as functions of silicon recovery in the process and silicon content of the alloy have been established. It has also been shown that the flue gas temperature can be used as an additional process control parameter. Comments are made on the effect of the dust formation on the whole process economics and it is pointed out that the formed microsilica dust is a valuable by-product and not an industrial waste. INTRODUCTIONFerrosilicon is produced in electric arc furnaces with submerged electrodes. The charge mixture consist s mainly of quartzite, coke as the reducing agent and iron chips. The products are ferro silicon and carbon monoxide, various other volatile materials, water vapour and silicon monoxide gas. Carbon monoxide and silicon monoxide oxidize at the charge surface when mixed with air entering through the furnace hood openings. The off-gas contains a considerable amount of dust, which is mainly very fine particles of silica formed as a result of oxidation. The emission of dust containing gases to the atmosphere causes serious pollution problems to the environment. Therefore, the control of the formation of the dust, preventing it from escaping to the atmosphere, and dealing with this very fine dust collected from the flue gases represent important technological and economical parameters in the ferrosilicon production industry.This paper is concerned with the relations between the quantity of formed micro silica dust, as a function of both silicon recovery and silicon content in the alloy, and various other technological parameters; and their possible effects on the energy consumption and economics of the whole process."

Jan 1, 1989

By F. Duan, J. Pfarr, J. M. Goris

"The U.S. Bureau of Mines, in cooperation with the Homestake Mining Co. and the University of Utah, is conducting a field demonstration to evaluate the behaviour of rock masses supported with cable bolts. One of two rock masses being studied is supported with both conventional and birdcage cables. This rock mass is located between the 6500 and 6650 levels of the 45-48N stope, 21 ledge. The second rock mass is the hanging wall of the D-limb stope between the 3500 and 3650 levels near the Ross Shaft and is supported with conventional cables. The primary objectives of the project are to monitor the behaviour of the two rock masses during mining using extensometers and cable support strain gauges, after which the rock will be modelled using the finite-element code UTAH III. Field data will be used to verify the modelling. In addition, a comparison between the effectiveness of conventional and birdcage cables will be made.45-48N StopeThe 45-48N stope is located in the 21 ledge between the 6500 and 6650 levels and contains about 233 000 short tons of mineable ore. The orebody lies within the Homestake Formation and is very irregular being approximately 200 ft long and 75 ft wide. Between the 6500 and 6650 levels, it dips from 35 degrees to 60 degrees east with a near-vertical plunge to the south. Mineralization is characterized by arsenopyrite and pyrrhotite with minor gold. The contact between the Homestake and the overlying Ellison Formation creates a plane of weakness along localized graphitic layers. The footwall dips at approximately 60 degrees but between 100 ft and 120 ft above the 6650 level , the hanging wall flattens to almost 20 degrees causing a significant mining problem."

Jan 1, 1991

By Michel David

"The usual complaint of mines is that grade does not match exploration expectations. Quite often, more tons are mined than expected but at a lower grade. This can be seen as dilution. Geostatistics can help predict which dilution can be expected both in terms of grade and tonnage for different mining methods.The usual vocabulary of geostatistics speaks of block distribution; block variance, size effect, information effect, all terms which say very little to the practitioner. In f act, all this can be rephrased in terms of dilution .In this paper, the following is presented - an example which shows how reserves change with the size of selection units and number of samples taken, and tables which show the dilution that are bound to happen when dealing with the commonly encountered log-normal distribution. Finally, the paper shows how grade tonnage computations should be made in the case of an arbitrary distribution. IntroductionGeostatistics progresses more and more rapidly if one judge s by the number and quality of papers published in Mathematical Geology or at APCOM meetings. More and more case studies describing successful applications are published (David et al., 1986)(Kwa and Mousset-Jones, 1987). It is estimated that more than 270/0 of the gold mines around the world use geostatistics. There is still, however, a lot of resistance from the remaining 73%. Geostatistics has more formulae and equations than it needs to reach year 2000. We will be well into the third millenium before all the models available now are actually used. The progress may come in the form of finding better ways to present known statistical results and getting away from the jargon of geostatisticians. One example may be in trying to explain how we can answer the most common plea of the mining industry: production grade is not what was expected in the feasibility study."

Jan 1, 1988

By Douglas G. Jay

"Transfer points on belt conveyors have long been a source of problems for both designers and users. Conveyors are generally given a low priority in new equipment layout, thus designers are often forced to compromise due to space limitations. Consequently, for this reason as well as for reasons of initial economics, many conveyors are supplied with less than adequate transfer points.Although not intended as a cure-all, a number of existing installations have been modified with the result that spillage has been reduced to a minimum and belt life has been extended. The most striking modification consisted of replacing conventional rigid frame idlers with five-roll catenary idlers.Although catenary idlers can be traced back to the early 1900s in North America, with a patent having been issued in Washington, D.C. as early as May 29, 1907, the practical application of this concept has only recently reached North America. Major installations include applications at St. Lawrence Cement in Oakville and Iron Ore Company of Canada in Sept-Iles, as well as belt conveyors at Stelco's Nanticoke plant and yard conveyors at Syncrude in Alberta. These installations were part of major capital expenditures for new facilities and included complete conveyor systems.However, this article will discuss the use of catenary idlers on existing rigid frame conveyors for the purpose of absorbing the energy of falling lumps, protecting conveyor belts and reducing spillage. We will deal specifically with an installation at Inco Metals Company in Sudbury, Ontario, where approximately 40 five-roll catenary idlers were installed on a 42-in.-wide belt conveyor handling ore located under the railroad car dumper at the Clarabelle Mill. Before-and-after photographs clearly show the tremendous improvement in the cleanliness of the location, and the savings in maintenance costs and extended belt life have prompted Inco to consider modifying other conveyors."

Jan 1, 1982

By Godfrey W. McDonald, Dennis E. Fredrickson

"Commercial coal mining has been recorded in Nova Scotia since 1863 and during this period an estimated 60,000,000 short tons of mine discard containing 10 1030% coal has been accumulated, Approximately 70% of these dumps are in the Cape Breton region and most are owned by the Cape Breton Development Corporation (CBDC), formerly DEVCO.The explosion of oil produced energy costs which created an increase in thermal coal demand as well as the desire to rehabilitate abandoned mine dumps encouraged coal reclamation. CBDC was receptive to a proposal from the Selminco Joint Venture and encouraged the building of the Princess Recovery Plant (1980) and The Summit Plant (1982).The mine dump contains scrap, waste rocks, coal and substantial quantities of fine shale. The scrap and oversize are removed and the remaining material slurried with water to a density of 1.45. The slurry is cycloned to separate the saleable thermal coal from the rejects which are returned to designated areas of the dump for contouring and revegetation.BackgroundThe recorded coal production in Nova Scotia from 1863 to 1980 was 390,000,000 short tons. This extraction was associated with an estimated 60,000,000 short tons of discarded material. This mining discard and coal washing plant reject are located in numerous, varying sized dumps throughout the mining areas. Approximately 70% of these dumps are in the Sydney coal field region of Nova Scotia. The coal content of these dumps varies from 10 to 30% coal with an average of 18%.Energy CostsThe explosion o f energy costs in the mid-1970s greatly increased the sale price of thermal coal which made recovery of coal from some of the dumps economical. The environmental benefit of these operations will be the rehabilitation of the dumps upon cessation of the coal reclamation operation."

Jan 1, 1983

By Aysan Molaei, Kristian E. Waters

"Solvent extraction is the one of the most common techniques for recovering metal ions from aqueous systems. However, it is not efficient in the extraction of low concentration metal ions from aqueous solutions. Predispersed solvent extraction (PDSE) is an alternative method for solvent extraction which implies colloidal liquid aphrons as extracting agents in order to reach higher interfacial area and lower reagent consumption. This work investigated important parameters in PDSE of nickel ions from dilute aqueous solutions by fractional factorial design of experiments. Four experimental parameters, the initial extractant concentration, initial surfactant concentration, equilibrium pH and phase volume ratio (organic to aqueous ratio) were investigated. The important parameters were determined as well as important interactions between these parameters. It was found that extractant concentration, phase volume ratio, and equilibrium pH are the most significant experimental parameters. However, the interaction between surfactant concentration and other parameters was determined as significant interactions.INTRODUCTIONNickel is one of the key components found in cars, mobile phones, rechargeable batteries, kitchen appliances, and steel industry (Anyadike, 2002). It is one of the most important metals produced by Canada which is in the five top nickel producers in the world. Despite a 24% decrease in the nickel prices from 2011 to 2014 the nickel global mine production increased by 36% between these years (U.S. Geological Survey, 2015; Nickel - Statista Dossier, 2015), which shows the increasing demand for nickel. This high demand leads producers to consider the production of nickel from low grade ores and other secondary sources such as process wastewaters. The removal of nickel ions from process wastewater is also important due to environmental considerations. Nickel is known to be a human carcinogen and it may cause serious lung and kidney problems, pulmonary fibrosis, gastrointestinal distress, and skin dermatitis if it exceeds the critical level (Borba et al., 2006; Fu & Wang, 2011)."

Jan 1, 2016

By L. C. Kitchener, K. Vollenwyoer

"This paper describes the development of an automated, 70-ton capacity, underground electric trolley truck at Inco Ltd. The purpose of the project is to provide a high capacity and high productivity haulage system to suit continuous loader applications in existing mining horizons where conveyor belt application is not immediately practical. IntroductionWith the start o f a program by Inco in mid-1983 to develop a continuous loader for bulk mining of our hardrock orebodies, the need for a rapid ore transportation system was recognized to match the increased extraction rates planned. Two methods were investigated, truck haulage and conveyor belt. As a result, a conveyor belt system has since been designed and installed with a continuous loader at Stobie Mine and an electric truck has been designed, fabricated and assembled, with shop testing underway. This paper deal s with the latter project. BackgroundMany existing mining horizons which could utilize continuous loaders do not have the straight runs required for conveyor belts. In these situations, truck haulage would be the only alternative of the other transportation methods that would be practical. In order to match the high productivity potential of the continuous loader, however, a more efficient trucking system is required than would be available with conventional diesel powered trucks or with electric truck designs commercially available, or under development. A higher capacity truck and an automated operation is necessary so that the application of additional units to suit increasing haulage distances matches loader output without reducing over-all productivity because of the need for additional operators.A first effort to work with a major electrical manufacturer was unsuccessful and resulted in a project delay of almost one year. In November 1984, an investigation into the concept was reinstigated with UTDC, and an agreement to start design was reached in April 1985."

Jan 1, 1988

By J. C. Thornley, H. L. J. Drummond

"Fifty years of wear on the original carbon steel shaft of this hydro turbine necessitated repair operations in 1980. Both austenitic and martensitic stainless steels have been used individually as journal materials in separate trials on an80-inch long and 22-inch diameter radial bearing but neither one nor the other has been successful.The wear and cracking problems of the stainless steels leading to the present abandonment of both classes of stainless steel are described. In particular the dependence of the toughness of type 410 stainless steel on its tempering temperature and the susceptibility of that steel to quench cracking are highlighted because problems have been caused by both of these metallurgical factors.IntroductionAs part of a desire to improve the efficiency of a fifty-year old hydro-electric generating station on the Saint John River, the decision was made to change the journal and bearing material for the shaft bearings, which are stave-type bearings. For the initial fifty years of operation the bearings had been wooden (lignum vitae) and had run on the carbon steel shaft directly. For one of the four unit s at this station the performance of this combination has been truly excellent, and the remaining three sets of bearings had performed well. However there had been shaft wear on the units and the wear had made the shafts somewhat elliptical when a decision was made to install some sort of new journal on to three of the old shafts. [In addition to the wear on the carbon steel journals it was found that one shaft was significantly softer in the bearing area than it was immediately above the bearings (180 Vickers in comparison with 230 to 250 Vickers)] ."

Jan 1, 1985

By W. A. Crosby, W. K. Smith, K. L. McDonald

"IntroductionThis paper describes how the introduction of two blasting techniques and the resuItant development of new dragline digging methods have increased the productivity of single- and double-seam dragline operations at the Rietspruit opencast mine.LocationRietspruit , one of South Africa's largest opencast strip mines, is situated some 11 5 kilometres east of Johannesburg in the Witbank coal field.BusinessRietspruit is a joint venture between Transvaal Consolidate d Land and Exploration Company (T.C.L.) and Shell, South Africa. Rietspruit is administered and managed by Rand Mines, the Mining division of Barlow Rand, transportation and marketing being the responsibility of Shell. The total saleable coal product, approximately 5,5 million tons per annum, is exported via Richards Bay.Presplitting and Throw BlastingPresplitting was initially introduced in September 1980, as a means of dewatering t he overburden and mid burden to facilitate the use of dry-mix explosives a s opposed to slurry explosives.The utilization of the throw blasting technique arose as a direct result of observed ground movement after the successful introduction of presplitting. The first trials commenced in March 1981 on the double-seam operation. The methods, economics and resulting advantages are fully described elsewhere. A brief description follows.Method of PresplittingAfter determining the desired presplit line, 250-mm holes are drilled to top of coal at 4-m to 6-m intervals, dependent on the competency of the rock overlying the coal. A single 60-kg charge of slurry explosives is located at the bottom of each hole, no tamping is used and all the holes are detonated simultaneously. The results are a competent, straight, vertical highwall. This enables accurate control of the first row of blast holes closest to the highwall, which is a prime requisite for successful throw blasting."

Jan 1, 1983

By A. Bouajila1

Minerals processing organisations will be more and more under intense competitive pressure. Major changes are being experienced with intense respect to resources, processes, production strategies and markets. As result of international competition, only the most productive and cost-effective operations will survive. That is why operators in the minerals industry have always aimed to obtain better performance from their processes along the mineral extraction cycle starting from exploration up to the smelting step if any. A principal ingredient and perhaps the most important one in the process of evolution toward improved productivity is the achievement and implementation of an error-free production synonym of an ignorance-free operation. This is, at the same time, a guarantee for quality, a minimising factor for waste materials production, handling and disposal, and a maximising factor for labour utilisation. The notion of ?error or ignorance-free? -usually identified as a ?made in Japan? manufacturing mythology, will sound, at first impression, like a pious ideal, to be striven for but impossible to attain. Nevertheless, the introduction of measurement and detection technology in the minerals industry along the last century should benefit from the today?s sensors and control systems that explosively expanded beyond their traditional production base into far-ranging commercial ventures. The fastness and spread of those technologies will play an important role in the survival of innovative plants. Their role in information assimilation, and control of operations to maintain an error-free production environment, will help many plants to stay effective on their competitive course. In this paper the feasibility of the zero process ignorance concept as applied to the comminution circuits will be discussed and the challenge behind this ambitious move toward improved productivity will be outlined. Examples of pre-competitive R&D projects started at COREM in order to fulfil this prerogative will be presented.

May 1, 2001

By Robert B. Parsons

"This article is based on a paper presented by Jim Scott at the 1988 annual convention of the Prospectors and Developers Association of Canada. The paper suggests a number of factors that might be taken into account in negotiating royalty terms.IntroductionRoyal ties are a part of mining life in Canada. They are used by many kinds of individuals in many kind s of situations. Prospectors commonly take royalty interests back when they transfer claims to development companies. Mining companies disposing of undeveloped (or sometimes even developed) properties are often paid at least in part by royalties. Royalties are even used by institutional investors with no other connection with the resource industry.Such different royalty holders have different investment goals, different cash flow requirements, and different risk / return preferences. These differences have given rise to a number of different royalty types. These types range from the simplest cents-per-ton royalty (where the operator pays a royalty at a fixed rate per ton milled) to net smelter return or ""NSR"" royalties (where the royalty is based on a percentage of the operator's NSR) all the way to net profit interest or ""NPI"" royalties (where the royalty is based on the operator's bottom-line net profit),The fundamental difference between the many royalty types is in the risk / return relationship. The cents-per-ton royalty, for example, is relatively risk-free. Of the many economic factors which affect a mine, the only one which will affect the royalty holder is the amount of ore physically milled. On the other hand, the potential for significant gains under a cents-per-ton royalty is also very limited. The royalty holder will not share in any increases in the market price of the end product or any cost reductions achieved by the producer."

Jan 1, 1989

By Simon Pelletier, Jose Delgadillo, Dave Page, Pramod Kumar, Raj Rajamani, Dilek Alkac, Martin Fillion

"In general, many past works examine mill load, mill power, shell lifter design etc with a view to improving the mill capacity. On the contrary, only a handful of papers have addressed the transport of fine slurry through the pulp lifters. We present the flow dynamics of pulp lifters via laboratory scale experiments, high speed photography and modeling with computational fluid dynamics. Next, the flow behaviour in ArcelorMittal’s Mont-Wright autogenous mill discharge flow is examined. In an effort to improve mill throughput, a comprehensive simulation and plant scale study of the mill was taken up with a focus on the shell and pulp lifter design. The shell lifter was found to be at its optimum limit for breakage of ore particles given the constraints of wear life and occupied volume. Next, the pulp lifter study was taken up with computational fluid flow code and discrete element code. The simulations directly showed that there was considerable carry-over of slurry. This effect was traced to the area restriction in the pulp lifter channels. Further, crash-stop studies confirmed slurry pooling within the mill. Thus it was readily apparent that mill throughput can be increased if the pulp-lifter could be redesigned. Consequently, the discharger section of the pulp-lifter was redesigned.First, this paper outlines the modeling in laboratory scale studies and plant scale studies leading up to the discharger design. Next, the discharge flow in seven different published mill surveys is predicted with computational fluid dynamics (CFD) methodology shown here. Finally, Mont-Wright mill circuit performance before and after the discharger redesign is described. The usefulness of fluid flow simulations in the design of pulp-lifters is emphasized."

Jan 1, 2012

By SangHyeok Han

Selecting the best possible cranes and identifying spatial conflict-free locations on sites can result in productivity and safety improvements for large-scale industrial construction projects. In the current practice, experienced lift engineers select cranes based on the heaviest lift and/or the largest lifting radius of the identified crane. This practice is relatively time-consuming, and optimization of the crane?s use and location is also difficult. There are many factors which need to be considered during the crane selection process, a reality which further complicates the process. This paper presents a framework which aims at developing a decision support system to enhance the crane selection process and collision-free path planning for large-scale construction projects. This paper utilizes an innovative crane selection matrix in order to establish a process for optimized crane selection for construction projects. The study considers more than 40 different factors in order to reduce time and improve safety for crane operations. Following finalization of crane type (mobile crane versus tower crane), a visualization model to simulate crane operation and identify collision-free crane operation paths is proposed. This process can assist project managers to plan the lifting process more effectively and efficiently. A case study-based approach was utilized to demonstrate the proposed methodology. The methodology was tested in the planning and construction process for boiler house structures in Mannheim, Germany. The project entailed numerous challenges: one of the major tasks was to lift a 102-ton load on the top of the boiler structure through crane collaboration; space limitations on site also presented several challenges related to crane selection, location, and operation processes. Based on the project constraints, the proposed crane selection framework, and the visualization models, two tower cranes were selected and successfully implemented in the case study.

Aug 1, 2013

By S. J. Cook

Copper, a world commodity, and the first metal used by man, played a great part in the beginnings of modern civilization, which rests so dependently on the utilization of metals. Then, long after the close of the so-called 'bronze age,' when iron and steel had attained great prominence as the world's most important metals, the practical application of electricity to industry and commerce, for the improvement of every phase of man's multitudinous activities, gave a new impetus to the production of copper. Improved metallurgical practice made it possible to work low-grade properties at a profit. Research disclosed many new uses for copper. The metal, now produced from the mines of the world in the proportion of about one pound to every 50 tons of pig iron, has attained an importance which rivals that of iron and steel in the commerce and daily life of every nation. New fields of copper-bearing ore have been discovered in Canada in recent years. Established mines in the United States and Chile are producing on a great scale. Africa looms up as one of the great question marks in the future of copper. Whereas, a few years ago, the end of the world?s resources was predicted as being in sight, the evidence now available seems to show that the copper production of the world is likely not only to continue, but to increase for a long time yet to come. Canada's future in copper is a great subject; in the present paper only a few of the most outstanding factors affecting Canada's destiny in this large field may be noted, but if consideration of the points raised herein serves to focus attention on the magnificent possibilities of Canada as a producer of copper, the preparation of the paper will be more than justified.

Jan 1, 1928

By Allan R. Punkkinen

Safe extraction of the valued ore resource in the deep levels of VALE Creighton Mine has progressed in a pillar-less fashion using vertical retreat, slot-slash and uppers retreat methods since the cessation of ?cut and fill? mining in the late 1980?s. Sequencing of the panel extraction and filling has been the key to successful exploitation of high stress orebodies at depth. In late 2010, discussions between the Operating Department and Creighton Ground Control revealed an opportunity to evaluate a trial primarysecondary sequence in the west end of the 400 Orebody at the 2340m horizon. To manage the trial primarysecondary project, a high level risk analysis and management of change was carried out to mitigate potential danger. As part of the requirements, an instrumentation project was conducted in the hanging wall and footwall bottomsills of the secondary panel and within the secondary panel itself. The extraction sequence was modeled with Map3D® software, confirming high stress levels with the advance of the primary panel. Enhanced ground support was installed based on modelling results. A key objective of the instrumentation project was to verify support system response to mining and to obtain knowledge in regards to the behavior of the stope. This paper describes the first time that this type of new innovative instrumented rockbolt technology had been used in a hard rock mining environment. Understanding of the physical deformation mechanisms of ground support in response to high stress conditions is the basis for an effective ground control strategy. The data played an important role in subsequent enhanced ground support system design at the mine and importantly, established the fact that the secondary pillar had not totally failed. Subsequent cavity monitor results helped establish that fact.

Jun 1, 2012

By K. Raht

LEAD poisoning is perhaps the oldest and, until recent years, the most misunderstood of all industrial diseases. Hippocrates appears to have recognized a relationship in the colic experienced by a patient who worked with metals, and the ancient literature is filled with references to the colics and 'dry bellyaches'. The colic and other sequalæ following drinking of lead-bearing waters and, particularly, wines has excited possibly more comment in the older medical literature than any other ætological factor. It was not until1656, when Stockhusen definitely connected the colic of the workmen with the fumes given off in the process, that the true danger to those working with lead was recognized. Unfortunately, something over 200 years elapsed before industry took any note of Stockhusen's discovery; it remained for Legge and Goodly and investigators of the early 1900's to forcibly educate their profession and industry to the manner in which lead gained entrance to the body. The work of Legge and Goodly was published in 1912 and the clearness with which these investigators presented the scientific data which they had accumulated will mark this volume as perhaps the first and most important contribution to our modern knowledge of the subject. It also ushered in a period when, in the short space of thirty years, lead poisoning has been reduced from one of the most baffiing and widespread o industrial diseases to one which can be anticipated and controlled. The next great contribution came in 1926 with the publication of the work of the Harvard group. Here, for the first time, was the physiological behaviour of lead laid bare, and it is to the discoveries of these authors that we owe our modern treatment of lead poisoning.

Jan 1, 1941

By G. D. Mcdowell, L. B. Cochrane, B. D. Thompson

"Abstract - Exploration for deep underground copper and nickel sulfide deposits in the Sudbury mining camp is carried out with surface drilling. More detailed drilling, with an advanced underground exploration program, may be necessary to establish an accurate interpretation of the deposit geology and upgrade the resource estimate to the measured category for reserve estimation and feasibility assessment. Resource evaluation is a lengthy and costly process that could result in a decision not to proceed with the project. For projects that proceed to production, significant reductions in the operating and capital costs could be achieved with a more accurate interpretative model of the deposit geology and mineralization. Quality control procedures to ensure the integrity of the drilling data and interpretation guidelines are essential steps in the development of a deposit model. The use of block modeling techniques and the application of geostatistics for resource estimation further improve the quality of the resource model.Significant improvements to the interpretive models can also be achieved by incorporating additional information from geophysical measurements to validate and constrain the geological interpretation. The geophysical models must be consistent with known geological environments and oreforming processes, which has required the concurrent development of comparative models from exploited deposits. These geophysical techniques can also provide key geotechnical information required for the optimum design of the mining method and mining sequence. The objective of this program is to improve the accuracy of the deposit model and the quality of the resource and reserve estimates in order to optimize capital investments and reduce the development and operating costs of underground mining projects. Several of these techniques are currently being tested at INCO Limited’s Sudbury operations. The results from those tests are presented and their applications are discussed within the framework of resource/reserve classification systems and project evaluation objectives."

Jan 1, 1998

By Graham Swan

The case is presented for the development of a spray-on liner for ground support, but only in the context of a new mining system, consistent with the technical and business case advantages of liners compared to alternatives. Over the past 10 years much effort has been expended in specifying and testing the mechanical/environmental properties of various liners, without actually fulfilling any mining system requirements. The results have been generally disappointing, with no consistent and sustained application in a dayto- day production environment being achieved, anywhere. Central to this shortcoming has been the failure of mining/liner ma nufacturing companies to realise that screen/mesh or shotcrete cannot simply be replaced with thin, deformable liners: success will depend upon closely defining and evolving a new, liner- functional mining system. The paper begins with a discussion of some fundamental technical capabilities and constraints associated with 3M Canada?s liner material that has been developed in partnership with Falconbridge Limited. Intended applications for this liner include the support of bursting ground associated with deep mining conditions. With safe application and consistent performance in mind, the paper argues for a new mining system that derives in the first place from best quality drilling and blasting practices. Taking this as a given, a system for waterscaling and liner application prior to mucking out is proposed, followed by bolting through the liner while arranging for the bolts to be explicitly connected to the liner. Some logistical and equipment related challenges of such a mining system are then reviewed and discussed in the context of the business case for liners. It is concluded that this approach, if successful, will provide the greatest benefits in the areas of safer mining, due to reduction in worker exposure, and in reduced mining cycle times.

May 1, 2003

By J. C. Salas, A. Weishaupt, J. A. Guzman

The origins of the electrorefining process date back to 1869, when the first ER cathodes were produced at Pembrey, South Wales. By the time that Pembrey was closing, Chuquicamata tank house was under construction, initiating in 1915 a long history of electrolytic cathodes production. Initially electrowon cathodes and later electrorefined cathodes were produced. During the history of Chuquicamata tank house, there have been several challenges associated with the quality demanded for electrolytic copper. Among them, the transformation from electrowinning to electrorefining in 1952, the onset of the direct commercialization of ER cathodes and the phase out of wire bars in the 80s, several technological changes including the implementation of permanent cathodes, and certainly the constant increase in complexity of the anodes refined. This paper explores the manner in which Chuquicamata has addressed these challenges and examines its links to process characteristics, which have been necessary to maintain a product quality according to market requirements and a brand, “CCC”, that is widely recognized worldwide. INTRODUCTION Located in the north of Chile, in the Atacama Desert, Chuquicamata is an open pit copper mine that for many years has played a relevant role in the global and local mining industry. Known from prehispanic times, the Chuquicamata deposit was initially developed between 1912 and 1915 by the Chile Exploration Company, the operating company of the Chile Copper Company controlled by the Guggenheim Brothers in the USA (Yeatman, 1916). Officially inaugurated on May 18th, 1915, by the President of Chile who pressed a button in Santiago sending a telegraph signal to the power generation plant specially built in Tocopilla, 1500 km north. It signaled the beginning of generating energy, sending it to Chuquicamata, another 140 km east (“El mineral de Chuquicamata”, 1915), marking the beginning of its industrial operation.

Jan 1, 2019