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By Li. L.

Backfilling has become a popular solution in underground mines around the world. It reduces environmental impact of mining industry and improves ground stability. In most cases, backfill has a high water content so that it can be delivered by pipes from a backfill plant on ground surface to underground stopes. Upon deposition in the stope, the backfill tends to consolidate under its own weight, leading to a generation of excess pore-water pressure. To avoid excessive pressure and protect the backfill barricade installed at the base of the stope, the backfilling of the stopes is usually divided into two stages: plug pour and backfill body pour. The interruption of backfilling operation is undesirable as it slowdowns the mining productivity, and sometimes causes pipe clogging, leading to unexpected increase in manpower cost and further reduction in mining productivity. The backfilling interruption time may be reduced, even eliminated if the drainage of backfilled stopes is sufficiently improved. This paper presents an application of wick drains, a material commonly used in civil engineering, to mine backfilled stopes to help accelerating the drainage. A protocol is proposed for installing the wick drains in a mine stope to be backfilled. Numerical simulations were made, showing that the drainage of the backfill can significantly be improved by the introduction of wick drains. The application of wick drains in mine backfill can thus be considered as a promising technique and merits deeper and more detailed investigation.

Aug 1, 2013

By A. S. Gendron

A brief description of Inco's ORC copper refinery tankhouse and the electrowinning tankhouse is followed by a comparison of the requirements for the production of the high-quality copper in both systems. The description will focus on both tankhouses, with emphasis on experience to date in the electrowinning tankhouse. Particular attention will be paid to sensitivities of each tankhouse to process upsets which can. significantly afject the quality of the product cathodes.

Jan 1, 1977

By D. J. Scarpato

"Slope construction in shale can present some interesting challenges for geotechnical design engineers and contractors alike. There are challenges that can be expected and designed-for; however, all too frequently, such challenges manifest themselves as “surprises” in the field. Common constructability challenges can include those such as drill hole deviation during drilling for controlled blasting; and, excavation slope instability arising from inconsistent perimeter control drilling. Drill hole deviation results from the cumulative effects from both drilling mechanics and rock mass conditions. Once a hole has initiated the deviation trajectory, it is difficult to rectify drill steel position. Although such challenges are not necessarily unique to shale, they are often exacerbated by weak, weathered and transversely isotropic nature of bedrock conditions. All too often, the working assumption is that shale is “soft” and easily excavatable; however, this blanket assumption can prove to be costly. This paper is intended to provide design professionals and contractors with the practical considerations needed to avoid the “surprises” associated with drill hole deviation, and minimize the potential for costly claims.INTRODUCTIONFor all the slopes that have been excavated worldwide, and for such advancements in excavation technology and field characterization, one might be tempted to believe that the industry almost has slope development down to a science. This is frequently not the case, especially for weak/weathered and anisotropic bedrock. Excavation contractors are still pushed to the limits of what their technology can achieve, and engineers are all too often called to the field during construction, to make potentially risky onthe- fly decisions relative to excavatability, short and long-term slope stability, and project safety. Although there have been a host of other research papers and journal articles that have been written on the subject of deviation over the past 30 years (Brown, Geen, Sinha, 1981), the problems associated with drill hole deviation are still all too frequent. This fact is especially true for civil engineering surface excavations in bedrock."

Jan 1, 2015

By Graham Farquharson, Jame Marshall

"Mining towns have always been an important part of Canadian geography. Many Canadians grew up in them. The frontiers of northern Canada would be a lot closer to the United States border but for the pioneering of new mines, new towns, and new transportation routes. Names such as Labrador City, Chibougamau, Val d’Or, Rouyn-Noranda, Kirkland Lake, Timmins, Sudbury, Red Lake, Thompson, Flin Flon, Yellowknife, Whitehorse,Trail and Kimberley are some of the better known larger communities that have grown to become major commercial and government centres, but which started as the base for a mining development.Many other smaller towns never grew beyond being small communities, dependent upon the local mine and many of these are still alive, but perhaps not quite what they used to be. In this list would be Buchans, Schefferville, Chapais, Cadillac, Virginia town, Lynn Lake, Uranium City, Pine Point, and Keno Hill.Nevertheless, all these towns and dozens more like them were residential communities where people lived and raised families and were quite accustomed to being days from the major centres of Montreal, Toronto, Edmonton and Vancouver, and not just hours away as wet end to measure travelling time today."

Jan 1, 1996

By M. Hozayen, E. S. Radwan, P. A. Nawrocki, A. Jebbouri

"A major geomechanical study was conducted for one of the UAE onshore oil fields with the purpose of studying reservoir rock properties and stress distribution, based on which a 3D coupled reservoir geomechanical model was built. This model was later used for wellbore stability analysis and for analyzing the effect of fractures on future reservoir production performance, including fracture deformation and permeability evolution occurring due to reservoir depletion and resulting changes in local stress field. The subject of this study was a complex fractured Upper Cretaceous carbonate reservoir characterized by high degree of heterogeneity, both vertically and laterally. Wellbore instability related drilling problems were encountered while drilling the wells in this field. The problems were mainly in drilling the horizontal wells, including breakouts and mud losses. Experimental results of laboratory tests are summarized in this paper whereas wellbore stability analysis and formulation of a 3D geomechanical model that was built for that purpose is summarized in a sister paper (Part II).A suite of tests reported includes tensile strength, uniaxial and triaxial compression and permeability under stress at simulated reservoir conditions. All tested rocks have been grouped into twelve test units and reservoir geology, rock types and challenges related to designing a viable sampling and testing program for a big reservoir are discussed first followed by sample selection criteria and details of the testing program. All test units showed brittle behavior at zero confinement and some samples showed similar behavior at low confining stresses. With confining stress increase, the behavior gradually turned to plastic but some samples showed features of ductile behavior even at low confinement.Obtained experimental data have been summarized in the form of strength criteria and correlations. The Mohr-Coulomb strength equations were obtained for each test unit and also for the averaged values. It was noticed that triaxial compressive strength (TCS) increases with decreasing porosity or increasing density but their influence on TCS is getting smaller with confining pressure increase. Good correlation of porosity and density with Young’s modulus, Poisson’s ratio, unconfined compressive strength (UCS), friction angle, cohesion and tensile strength has been noticed and there was an increasing trend between the confining pressure and TCS. Rock type (mud or grain supported) was not influencing the TCS as much as porosity and density and the two lithologies encountered affected TCS approximately in the same way. These results and correlations are summarized and explained in this paper. They were further used in the numerical modelling part (Part II) of this paper, Hozayen et al. (2015). It is also concluded that rock lithology is not a decisive factor and mechanical properties of tested rocks should be rather considered dependent on porosity and permeability. This helped greatly in reducing the number of tests that had to be performed."

Jan 1, 2015

By G. Girard, A. Larouche, J. Colbert, G. Doyer

"The Direct Chill (DC) casting process uses water to extract heat from molten aluminium and helps to control the solidification process. Many factors such as the water flowrate, water distribution around the mould and water impingement angle have significant impacts on the solidification process. It has been noted that the chemistry variation of the cooling water is also an important factor that has a major impact on the presence of defects on the ingot. A significant change in the water quality can produce defects on the ingots such as cracks, bleedouts, or runouts. Understanding the impact of water quality variation on ingots is therefore essential to ensure good ingot production and reduce defects. This paper aims at describing a new approach to follow the variations of process water quality over time. It is an original and innovative method, which is still under progress. A water quality and stability index (WQSI) is under development to evaluate changes in the water composition based on water physico-chemical parameters. The index is calculated by comparing each of the actual parameters with historical values previously modeled by a statistical law. It is a dimensionless number having an adjustable weight factor for each parameter. The positive or negative contribution of each parameter, with respect to the water cooling capacity, is taken into account to calculate the WQSI. The current selection of parameters is based on knowledge from the literature as well as on empirical experience. When the developed tool will be mature, it could be used to track water variations upon time and anticipate problems, enabling proactive actions to ensure good ingot production.INTRODUCTIONFor many years, the impact of water chemistry on heat transfer, during DC casting, has been of great interest in the aluminum industry. Several papers have been published to demonstrate the correlation between water chemistry and heat transfer (Yu, 1985), (Gildemeister, 2014). Although numerous studies do present the effects of water parameters (i. e. hardness, conductivity, oil, and grease…) on cooling capacity under controlled experimental conditions, they do not reflect the strong interactions between the parameters and variations present in a casting center. Wells and Cockcroft also demonstrated that laboratory based studies are not fully representative of real heat transfer in an industrial casthouse, there are too many factors involved (Wells, Li, & Cockcroft, 2001). In this context, it becomes very difficult to obtain a quantifiable relationship between the capacity of water to cool the ingot and ultimately the performance of the cast."

Jan 1, 2016

By A. E. Cameron

MR. N. T. AVARD : I would like to congratulate Dr. Cameron on his presentation of some pertinent facts about the Coal Resources of Nova Scotia. There is no question but what there is something very definitely wrong about the coal mining situation in this Province. These are times when we can with profit look facts in the face and attempt to solve some riddles. Perhaps now is the time when we can bring some of these coal mining facts into the open and look them over. Co-operatively, we might evolve some helpful solutions. However, I would like, first, to make some specific reference to the Joggins coal field, not as a mining expert, but rather as an executive who has evolved some ideas after some years of practical contact with this field. Dr. Cameron states that existing operations in this area will probably continue for a few years. As a matter of fact, under normal conditions, these mines are good for another twelve years. With the installation of more powerful equipment for hoisting, pumping, and ventilation, an additional five years could be counted on. With one exception, that pretty well clears up mining from the outcrop, hitherto the only method of approach in this field. The chief reason for this present limitation is prolific 'bootlegging' operations. It is too bad that these should have been permitted to ruin a valuable coal field. Moreover, I am cold by competent authorities that this need not have been so. At one time shortly before war broke out there were 74 bootleg operations within an area of one square mile around Joggins. However, despite the fact that these operations were illegal, I could not find any means of stopping then and I believe the same conditions existed in many other coal areas in the Province. For some reason, the eyes of the law were closed. The result is that many outcrop possibilities have been permanently ruined. The exception noted in the so-called Queen seam, which has definite possibilities for approach through the outcrop. This is probably the best coal in the district.

Jan 1, 1944

By John C. Taylor

"The non-ferrous pyrometallurgical industry has been under extreme pressure since 1980 and significant changes are taking place, principally in the copper, nickel and lead industries. This paper reviews some of these changes, particularly with respect to smelter capacity, major technical trends, and the industry's response to increased energy costs and environmental constraints.The Canadian metal mineral production for 1985 has been estimated at a value of over $8 billion, of which half is derived from copper, nickel, lead and zinc production. It is in our national interest that the Canadian industry remain competitive in the world market and continue its traditional contribution to the Canadian economy. IntroductionPyrometallurgy by definition requires energy, usually in the form of fuel, and produces process gas streams which can no longer be discharged directly to atmosphere in most countries. While the industry has been under varying degrees of pressure over the past fifteen years, it is just since the early 1980s that major changes have taken place, due, to a large extent, to an oversupply on the primary metal markets and depressed prices. These factors, combined with a surge in the price of oil, have resulted in some trends developing which must be recognized by those in the industry who plan to be in operation and competitive in the next decade.Although the value of Canada's mineral production, in terms of constant dollars, has decreased by more than 35% over the period from 1980 to 1985, the bulk of this production is exported and the industry still makes a significant contribution to the Canadian economy."

Jan 1, 1988

By Hamid-Reza Manouchehri

Coarse particles flotation is controlled by detachment (particle hydrophobicity and flotation cell turbulence) For composite particles (the bubble may attach to good hydrophobic region, but the expansion of the three phase line of contact is limited. Hence, the equilibrium contact angle, characteristic of the hydrophobic region, may never be attained, and the force of attachment is decreased relative to that possible for homogenous hydrophobic surfaces.

May 1, 2013

"A 3-dimensional finite element model for stress/stability analysis of rock excavations in underground mines is presented. Developed for use on personal computer under OS/2 operating system, the model employs the 8-node isoparametric brick element and accounts for such loading conditions as in situ stresses and gravity loading of the rock mass. In addition, modelling of backfill in mine stopes as in situ stress-free material is incorporated. Material failure is assessed by Mohr-Coulomb or Hoek-Brown failure criterion. A mine design example is presented to illustrate the potential use of the model as a tool for stope design.IntroductionNumerical modelling of mine structures has become a vital tool for mine design in recent years. The need to maximize ore extraction ratio and to reach deeper mineral deposits underground has led the mining industry to employ numerical methods of analysis to undertake complex ground control studies in order to better understand the ground response to mining excavations and to evaluate the ground support requirements. Thanks to the rapid developments in computer technology, it is now possible to perform very comprehensive analyses including, but not limited to, 3-dimensional, elasto-plastic, or large deformation or time dependent nonlinear analyses on personal computer.During the past ten years or so, many researchers undertook 3-D finite element analyses of rock mechanics problems in mining engineering. The following is only a sample review. For example, Chan'!' used three-dimensional finite elements to study the mechanical response of jointed granite during shaft sinking at the Canadian Underground Research Laboratory. Wang et al.(2) performed 2-D and 3-D finite element analyses of room-and-pillar mining system with flat and rolling coal seams. Thatejatu used three-dimensional finite element method to examine the problem of branching tunnels. Dolezalovaw used three-dimensional finite elements for the analysis of tunnel-face advance with partial excavation as well as full-face excavation in combination with rein for cement of the face by long anchors. Peili (5) used three-dimensional finite elements for the simulation of rock-liner interaction near the tunnel face."

Jan 1, 1992

By W. Pietsch

For a number of reasons, solids entering and leaving facilities for the treatment of minerals are becoming increasingly finer. Such materials pose problems throughout processing. Solids featuring small particle sizes tend to dusting, result in losses and segregation, exhibit various storage, transportation, and metering problems, and fine particulate effluents can not be easily captured, used and/or recycled. Sustainable mineral processing must minimize the exploitation of natural resources and avoid the need for disposal of wastes. The first requires the use of lower quality raw materials and upgrading, which typically results in the production of fine grained concentrates, and the latter encourages the recycling of wastes and byproducts or efforts to investigate them as sources for secondary raw materials or other beneficial applications. To overcome the difficulties associated with fine particulate solids, size enlargement by agglomeration is necessary. The resulting products have free flow characteristics, do no longer dust or segregate, and are sized and shaped as required for optimum processing. In addition, agglomerated materials may be engineered to feature desirable structure, composition, and a number of related, improved properties. Such engineering may be applied for the modification of fine run-of-mine and up-graded minerals as well as the production of secondary raw materials from by-products or wastes. By the interdisciplinary application of size enlargement by agglomeration waste-free processing of minerals becomes feasible.

Jan 1, 2004

By Edward P. Barrett

Iron ore, when subjected to reducing gases at a temperature suitable for reduction of the oxide but not high enough to melt the ore or metal formed, is converted into metallic iron. The product, being the original piece of iron oxide minus its oxygen, is sponge-like in appearance when viewed under a magnifying glass, and hence is called 'sponge iron. Sponge iron was probably the form in which some of the first iron was recovered from the ores. As early as the eighth century the Catlan forge developed into a low shaft furnace known as the high bloomary, in which iron was produced in the form of a pasty mass. These furnaces were increased in height, and with increased temperatures came the production of liquid cast-iron, at first undesirable because of lack of knowledge of methods for working it. In 1340 the first true blast-furnace was built iri Belgium. Some castings were made, but the greater part of the iron was converted into wroughtiron blooms by a crude puddling process. Charcoal was the universal fuel until the latter part of the seventeenth century, when coke was first used in England. Larger scale developments of methods of refining pig-iron followed. In I 885 Bessemer built his first converter in England, and within a few years the Siemen' s regenerative open-hearth furnace was developed, also in England, to produce steel. Then followed the enormous expansion in the metallurgy of iron. The idea of a direct process for the production of iron and steel has persisted during all of this time.

Jan 1, 1925

By A. LA. Salama, D. B. Hyma

"The Western Research Centre (WRC) of CANMET located in Devon, Alberta, is a modern research facility offering services ranging from fundamental research to pilot plant investigations. Recently, a 0. 76 metre diameter by 7.9 metre high Flotaire column flotation cell was installed as a demonstration unit for Canadian coal producers. Because the column cell is intended to be used for research, development and demonstration, WRC recognized that additional sensing equipment and improved process control would be required to generate good data for subsequent column scale-up and engineering design.A low cost, personal computer based control system was, therefore, designed and installed. This paper describes the stepwise procedure in developing the control strategies, selection of system software and hardware, and installation and configuration of the system.Preliminary performance data on a western Canadian coal sample are also presented. Future testwork is planned on additional coal samples to expand upon existing database."

Jan 1, 1993

By C. Mills, A. O. Burt

"The paper examines the role of gravity concentration in both an historical context and within the modern mineral processing industry. It discusses the principles of the process on both a theoretical and practical level. The importance of more mineralogy and its effect on the choice of the wide range of equipment available is discussed. The paper concludes with a discussion on the relative merits of gravity concentration with other forms of processing.IntroductionIt is an unfortunate, albeit popular, misconception among otherwise enlightened engineers in the mineral processing industry that gravity concentration was a process developed in the dark ages, perfected in the middle ages, and abandoned in the modern ages.Gravity concentration was developed in the dark ages - long indeed before that. Agricolau: cited examples of gravity concentration, crude examples admittedly, being practiced over 3000 years ago. However, gravity concentration is not dead. Far from it. As recently as 1978 it was reported that the total mineral tonnage treated by this process in the United States was greater than that processed by flotation. Coal represents the bulk of the or e treated by gravity separation in the U.S.A., with iron ore representing a major portion of the balance."

Jan 1, 1985

By W. Díaz, R. A. Parra, L. E. Arias, C. A. Toro, M. Marin, E. Balladares, V. Parra, G. Reyes, S. N. Torres, D. Sbarbaro

This work presents visible-near infrared (VIS-NIR) spectroscopy measurements, and signal analytical techniques to characterize minerals and relevant pyrometallurgical process variables for the copper extractive industry. Data signal processing techniques such as baseline correction and numerical analysis are used to estimate the continuous and discontinuous spectral components. Such spectral components are used to estimate the process temperature, and patterns such as the integrated radiation. Also, metal combustion emissivity calculation are depicted. Our findings suggest that VIS-NIR spectroscopy may be a suitable technique to assess the process condition state, appearing as an interesting sensing alternative. INTRODUCTION Although the flash smelting process is one key stage in the copper extractive industry, representing about 40% of copper matte production worldwide (Cantallopts, 2017), few attention is dedicated to develop sensing solutions to assess process variables, such as mineralogical composition and temperature, in the feeding and bleeding stages, compared to the steel industry (Strakowski, et al., 2014). In this process and other industries, e.g. the thermoelectric power generation one, combustion and particularly the generated flame are the production chain’s heart. Since the flame is a highly radiative emitting process where chemical and physical transformations take place, many works had been dedicated to characterize the combustion state by sensing its radiation using optical and photonic technologies (Ballester & García-Armingol, 2010). In this context, this work aims to contribute with visible-near infrared (VIS-NIR) spectroscopy and pyrometry techniques to retrieve relevant information from a laboratory scale flash smelting process. On the other hand, since photonic instrumentation allow us to perform contactless measurements of emitted, absorbed, transmitted or scattered radiation, it appears as a suitable technique for sensing process properties in harsh environments, e.g. high temperature processes. One of these techniques is the Visible- Near Infrared (VIS-NIR) spectroscopy, which provides information about the spectral radiation intensity distribution, in this work, the emitted flame’s radiation. It is well known in combustion research that the spectral emission from a flame is composed by a black body continuous radiation background, molecular emissions, elemental emissions and additive noise features (Arias et al., 2011). To make sense of such information signal processing techniques are needed, here we propose to analyse the continuous and discontinuous spectral components separately.

Jan 1, 2019

By Akiyoshi Horiuchi, Manabu Kanno, Shigeki Sato, Taro Aichi

"AKITA ZINC Co., Ltd. (Iijima Zinc Refinery), jointly owned by DOWA METALS & MINING Co., Ltd.(DMM), has used the company’s own hematite process for iron control since the beginning of operations in 1971. The hematite process consists of reductive leaching with SO2 gas and iron removal in autoclaves by high temperature hydrolysis. This process enhances not only zinc recovery but also the recovery of gold, silver, copper, lead and rare metals, which is carried out at another DOWA metallurgical plant. All by-products produced in the hematite process are marketed and sold. This paper presents an overview of the hematite process and the recent process improvements made.INTRODUCTION DMM carries out mining and smelting activities for precious metals, PGMs, rare metals and base metals such as copper, lead and zinc. It owns KOSAKA SMELTING & REFINING, producing copper and lead, and the AKITA ZINC Co., Ltd. (AZC) in Akita Prefecture. DOWA is a specialized smelting company which has established a metallurgical complex for copper, lead and zinc, including a recycling business. AZC was established in 1971 at a production capacity of 72,000 t/y zinc; it is jointly owned by DMM and five other non-ferrous metal companies. AZC has increased its capacity continuously and now produces 210,000 t/y of zinc. Figure 1 shows the changes in zinc production and capacity at AZC."

Jan 1, 2016

By Scott Hean

"Environment and the economy are interwoven irrevocably. They need to be publicly discussed, and discussed often so that new approaches can be understood and developed - approaches which are complimentary, not confrontational.Discussion on the environment is timely, from the perspective of mining engineers and developers, from that of bankers and from their shared perspective as people concerned with enhancing the quality of life, the environment and the economy.This paper will touch on how what is called the ""environmental economy "" that has evolved has become entangled with regulatory and financial issues in a way that is dangerous for all of us. It will also look at some of the promising possibilities that a world-wide and continuing concern for the environment holds out for us.For many decades, British Columbia has provided some of the key examples of the intertwining of environmental and economic issues, and, very importantly, providing the people prepared to do something about them.Canada's first environment minister, the late Jack Davis, came from British Columbia. He led this country's delegation to the Stockholm Environment Conference in 1972, a conference that laid the groundwork of principles necessary to establish some international certainty as to the legal liability for causing trans-national environmental damage.Another British Columbian who was also a national environment minister, John Fraser - now the Speaker of the House of Commons - was one of the first to dramatize the importance of acid rain and force it into the international public arena.Some 20 years ago, British Columbians made Vancouver and their province one of the major centres of opposition to the Alaska Pipeline and Tanker System - with some justification, it now seems.That a British Columbian , then MP David Anderson, was given legal recognition to sue in a United States' court against a system that was either in U.S. territory or international waters was an important precedent in, and of, itself in terms of environmental law. That old controversy is now a very current case study - in terms of dealing with the question of liability.-"

Jan 1, 1991

By C. H. Bertoni

"The Superior Province of the Canadian Shield is the largest gold producing area within Archean greenstone rocks in the world, with total production of over 140 million ounces of gold. One hundred and fifty-five mines have individually produced more than 8,000 ounces, although only a relatively limited number of deposits (33) produced more than one million ounces of gold. The output from these 33 deposits accounts, however, for 85% of total gold production. The majority of grades (68%) ranges between 0.10 and 0.30 ounce per ton, and there is no linear relationship between grade and tonnage.Development of new gold mines reflects the history of gold prices. However, the response to the latest increase in gold prices was not as marked. It is concluded that gold deposits are becoming increasingly more difficult to find and new exploration techniques are urgently required.IntroductionWith most of its production coming out of the Superior Province, the Canadian Shield is the largest producer of gold from Archean greenstone rock s in the world. In total gold production, the Superior Province is surpassed only by the paleo-placers of Witwatersrand and the placers of the USSR (Anhaeusser, 1976). There has been no attempt so far to compile the historical production of the Province as a whole in a single document. The aim of this work is to fill this gap, not only for the convenience of having a complete list of gold producers, but, more importantly, as a basis on which to study the tonnage and grade characteristics of these deposits."

Jan 1, 1983

By E. M. De Souza, R. Penner

"Water is encountered at the majority of underground mines, both over their lifetime and during each stage of development and production. The dewatering system is one of the most important and costly components of an underground mining operation and it is often not well designed and analyzed. An effective design of a mine dewatering system will greatly reduce its energy cost as well as improve working conditions and reduce production costs. A computer-based system, called Qpump, has been developed to assist the underground operator to effectively design and/or assess over-all and local mine dewatering systems. The design features and principles used in the development of Qpump are introduced and an example which illustrates typical applications is presented.IntroductionTraditionally, dewatering operations have been given lower priority than many other operations in underground mining. Invariably water will be encountered during the sinking of the mine shaft, during development and subsequent production. The dewatering system thus becomes a very important component of an underground mine operation and, in fact, any mine manager will attest to the importance and necessity of an efficient mine dewatering system.The water problem is of varying importance at different mines. There are several factors that contribute to the water encountered. It is a function of the mining method and techniques utilized (backfill system, drilling and raising technology, dust control sprays, shaft water rings, etc.) and of prevailing conditions (ground water, rock structure and permeability). In some cases a mine may be so dry that little pumping is required while in others, the weight of water pumped may exceed by many times that of ore mined.The successful design and application of a mine dewatering system is dependent upon the operating conditions of each specific operation. There are no standard procedures and systems which can be used for all mining situations. However, an effective water system will greatly reduce the energy and production costs of a mine, improve working conditions and eliminate headaches because of flooded working places."

Jan 1, 1993

By T. E. Smith

"This paper describes the application of a motor-driven flywheel unit, known as a peak shaver, to compensate for the cyclic load fluctuations of a large electric dragline installed at Pine Point Mines, near Great Slave Lake in the Northwest Territories. Of particular interest in this application is the fact that the power system supplying the dragline is a relatively small isolated system, with the major generating source approximately 170 miles from the mine.The cyclic load fluctuations of the dragline are theoretically capable of producing a maximum swing of up to 11 megawatts, which approaches nearly 50% of the installed generating capacity. To reduce these load fluctuations to acceptable limits various alternatives were considered, leading to a decision to install a peak shaver to optimize the operations of both the mine and the power system. Without the peak shaver, the dragline operations would be severely curtailed and additional diesel generation would have to be run at considerable expense, otherwise the power system frequency fluctuations would be totally unacceptable. With the peak shaver, power and frequency fluctuations are kept within tolerable limits, and optimum economic operation of the diesel generation is obtained.The paper outlines the steps leading to the selection of the peak shaver as the compensating device, describes the equipment installed and gives details of operating experience with the dragline/peak shaver combination since installation early in 1979. This .peak shaver is the first of its kind in North America, the only other peak shaver installation being in Australia.IntroductionPine Point Mines Limited owns zinc-lead mining and milling operations located at Pine Point, Northwest Territories, 5 miles south of Great Slave Lake (Fig. I). The company is staffed and managed by Cominco Ltd., which has a 69% interest in Pine Point Mines.Mining activity in the Pine Point area was first recorded in 1898, when the Yukon gold rush was on, but when the zinc/lead showings in the Pine Point area did not yield much in the way of gold, interest in the area soon waned. Cominco Ltd. first acquired some claims in the Pine Point area in 1928, but interest was sporadic until the early 1950s, when extensive exploration indicated rich pockets of zinc/lead ore near the surface. Pine Point Mines Limited was formed in 1951, with Cominco acquiring a majority interest in the company."

Jan 1, 1980