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By Les Johnston

_ BACKGROUND - About EPCOR - Genesee Generating Station - Phase 3 Expansion _ TECHNOLOGY SELECTION - Selection Criteria - Combustion Options - Flue Gas Emission Control Options _ STAKEHOLDER VIEWS _ PROJECT STATUS _ EPCOR is an integrated utility company for water, gas, electricity and technology services. _ EPCOR has about 1.6 million customers in Alberta, Ontario, Manitoba, BC, and the U.S. Pacific Northwest. _ EPCOR Generation Inc. operates three power stations in Alberta which were in operation before deregulation, including the coal-fired Genesee Generating Station. _ EPCOR Power Development Corporation owns generating stations in Alberta, BC and Washington State and will be building the Genesee Phase 3 expansion.

May 1, 2002

By S. McCalpine, W. Muir, P. J. Downey

"Golden Bear Operating Company Ltd. (GBOC) was a joint venture between Chevron Minerals Ltd. and North American Metals Corp. that was formed for the development of the Golden Bear Project. The mine is located at Muddy Lake, Western British Columbia, approximately 80 km northwest of Telegraph Creek and 135 km west of Dease Lake (see Figure 1). Road access to the mine was developed by Golden Bear and consists of a radio controlled 155 km gravel road originating at highway 114.A feasibility study was completed in 1987 and project approval was finalized in 1988 with Golden Bear issuing a ""Request For Proposal"" for detailed engineering in May 1988. Golden Bear also commenced negotiating with vendors at this time for the supply of the two principal process equipment packages: the dry grinding and classification system and the whole ore roaster package.Process plant engineering and plant construction was completed in October 1989 with plant startup commencing in November 1989. Two months into the commissioning phase it became apparent that the plant, as designed, would not achieve the anticipated production targets.Kilborn Engineering Pacific were subsequently contracted by GBOC to review and modify the plant design, assist the operating personnel with plant commissioning and startup and provide operator training.This Paper describes some of the problems encountered during the startup and the plant modifications incorporated to achieve design parameters."

Jan 1, 1992

By Peter Wells, Gordon Marrs, Dominic Fragomeni, Warren Holmes, Daryl Macnamara

"LocationThe Strathcona mill ofFalconbridge Limited is located in Onaping, Ontario, 50 km northwest of Sudbury.GeneralOre from the Falconbridge mines in the Sudbury Basin (Strathcona, Fraser, Onaping, Craig and Thayer Lindsley mines) is processed through the Strathcona mill with 8500 t of nickel ore and 1500 t of copper ore being treated daily. Current capacity is -3 Mt of ore at 1.8% Ni, 1.9% Cu combined grade. Custom feeds are also processed. The valuable minerals in the ore are pentlandite (FeNi)9S8, chalcopyrite (CuFeS2) with some cubanite (CuFe2S3) and very minor nickel sulphides/ arsenides. Cobalt is present mainly in solid solution in pentlandite. There are small but economically important concentrations of precious metals including platinum, palladium gold, and silver. The common non-sulphide gangue minerals are feldspar, quartz, mica, talc, and chlorite while pyrrhotite (Fe7S8) is the major gangue sulphide. The pyrrhotite contains between 0.6% and 1.2% nickel in solid solution and additional nickel as exsolved pentlandite in micron sized blebs. The nickel and copper ores are batch-crushed in a two stage dry crushing plant and then ground in separate circuits. Concentration by flotation and magnetic separation produces a nickel concentrate assaying approximately 16% nickel plus copper and a copper concentrate assaying 30% copper and 0.4% nickel. The nickel concentrate is trucked as a slurry to the Falconbridge smelter while the copper concentrate is trucked as filter cake to the Kidd Division of Falcon bridge"

Jan 1, 2000

By D. M. Wyslouzil

"This paper was prepared for presentation at the 16th Canadian Mineral Processor's Annual Meeting, Ottawa, Ontario, Jan. 17 to Jan. 19, 1984.This paper gives an account of the development of treatment procedures for the differential flotation of refractory copper-zinc ores. Special references are made to the effectiveness of various zinc depressants and their combinations.Studies carried out on refractory copper-zinc ores demonstrated that conventional zinc depressants such as cyanide and zinc sulphate were not particularly effective when secondary copper minerals were present in the ore; the flotation activity of sphalerite was enhanced in the presence of cyanide.Among the various zinc depressants evaluated, the following depressant combinations were found most effective: Zn(OH) 2-S02 , 802-CaO, Na2S-Na2S03-S02, Na 2 S-S02 and Na 2S-S0rDS22.The practical application of any of these systems depends on the type of ore treated and other conditions such as pH, levels and points of collector and depressant additions.In this paper the effect of each depressant combination on different ores is described with reference to the selection of collectors."

Jan 1, 1984

By M. Pekguleryuz, S. A. Argyropoulos

"The recovery of additions in light metals is an important parameter influencing consistency of the finished product, which ultimately means cost. Recovery is a function of many parameters such as assimilation speed, addition density, addition practice, liquid metal processing conditions, etc. In liquid metal processing operations, it is desirable to have the maximum possible recovery at the shortest possible time.In this paper a new index will be presented, namely, the rate of recovery (RR). This index quantifies the addition recovery and introduces the time dimension in the recovery increase. As such, the RR equips the liquid metal practitioner with an accurate picture of addition assimilation in liquid metals. Results will be presented on how this index is applied to a variety of additions in liquid aluminum. IntroductionThe data on addition assimilation kinetics offer a valuable parameter describing how fast a given addition enters the metal bath. These data may be expressed as gr m-2 s-1 of additive for a set of experimental conditions which might include bath temperature and degree of bath agitation among others. However, the liquid metal processing practitioner is more interested in the recovery of additions. In other words, the point of interest is the percentage of the used addition entering the metal bath. Ideally, the addition recovery can reach the 100% level. However, in practice, the addition recovery never or rarely reaches that level. Many factors can contribute to this. Some of these factors can be slow assimilation kinetics, addition density, addition practice, turbulence of the melt, etc. In some cases, sloppy addition practices can contribute to low recoveries, or even worse, to erratic recoveries.In this paper a new parameter is introduced. This parameter relates the maximum addition recovery observed over the time needed to achieve this maximum recovery."

Jan 1, 2002

By Hassan Ghaffari

? HPGR Process/Overview ? HPGR vs. SAG ? The Manufacturers ? Mine Operations using HPGR ? Projects by Wardrop/Tetra Tech ? Economic Benefits ? Questions Main Operating Parameters ? Press Force (N/mm2) ? Roll Speed (m/s) ? Moisture Content (%) ? Feed Particle Size Distribution Specific throughput M* = throughput/D*L*V (ts/hm3) Flake thickness/strength in balance with the compressing force (floating roll situation)

Aug 1, 2013

By E. W. Johnson

"The title of my paper is ""I 'Wonder Where The Yellow Went"". As you can readily guess, it is not related to an old-fashioned ""Pepsodent"" sales pitch! Rather, it concerns a situation which arises all too frequently in some gold milling operations, namely when actual ounces of gold production do not come up to estimated or projected ounces. The boss man scratches his head and wonders where the missing gold has gone and how it has disappeared. The problem, if one exists, is amplified if one forgets that an estimate is just that - an estimate - and not a hard fact - even though the numbers are produced by computers. And yet, from the point of view of engineering; financial and production planning and security; it is most desirable to tie together all data relating to production estimates, losses and actual production.In the course of this paper reference will be made to the term ""variance psychology"", to a few of the physical properties of gold and to the nature of its occurrence in Canadian ores, in relation to the topic under consideration. Activities which have a bearing on production estimates will be reviewed. These include: weighing, sampling, assaying, estimating residual losses and, in cyanide plants, gold precipitate production. Mention will be made of apparent, unaccounted for and unknown losses. In conclusion, I shall draw from personal experience and relate three examples of ""Where the Yellow Went''."

Jan 1, 1986

By K. Sugawaral, W. Tongampl, K. Hiruta, Takasaki Y., A. Hosoi, T. Katol, A. Shibayamal

Printed circuit boards of discarded personal computers, televisions, mobile phones and so on contain a significant amount of valuable metals. For the recycle of valuable metals contained in the printed circuit board wastes (P CB W), the effect of temperature on chlorination-volatilization of metals under chlorine gas flow was studied. The experimental sample used was powder of two types: crushed PCBW (Sample 1) made from PC and industrial machines, and crushed-combusted PCBW (Sample 2) made from Sample 1. The principal element in Sample 1 and Sample 2 was copper, about 13 wt% and 20 wt% respectively. Sample 1 was composed of pure metals such as copper, tin and lead. In comparison, Sample 2 consisted of oxide metals such as copper oxide, tin dioxide and silicon dioxide. The two samples were heated at predefined temperatures (ranging from 300 °C to 900 °C) in chlorine gas. The chlorine gas flow into the furnace was set at a rate of 100 mL/min. As a result, copper in Sample 1 began to volatilize at 600 °C and completely vaporized at 700 °C. While in Sample 2, copper started to volatilize at 600 °C and reached 100% vaporization at 800 °C. For Sample 1, zinc finished volatilizing at 500 °C, while for Sample 2, zinc volatilization reached only about 80% (maximum). Also, lead, nickel and titanium showed similar results. Consequently the volatilization rate of Sample 1 is higher than Sample 2 and the temperature dependency was verified for copper, lead, zinc, nickel, antimony, titanium and chromium. In fact, the volatilization rate of these metals increased with the temperature. This result reflects the difference between pure metal and metal oxide, as Sample 2 was combusted before the chlorination-volatilization test. Moreover, the chlorination reaction may be accelerated by a reductive atmosphere because Sample 1 contains carbon. In this study, the volatilization behavior of some valuable metals in PCBW by chlorine gas was observed. Further improvement in the rate of volatilization can be achieved by optimizing the experimental conditions.

Jan 1, 2011

By J. S. Redpath, W. R. Dengler

"A description of the equipment used and the electrical-mechanical problems encountered in sinking a deep shaft is given. This shaft is currently being sunk to a depth of 7,115 feet. Some of the features of the sinking plant are a 6,500-hp double-drum hoist, a Blair stage hoist, special high-capacity mucking gear, a Galloway stage, high-tensile stage suspension ropes and 12-ton sinking buckets.INTRODUCTIONIN THE EARLY FALL OF 1965, a contract was let, by The International Nickel Company of Canada, Limited, to Shaft Sinkers (Canada) Limited -J. S. Redpath Limited -Joint Venture, • to sink and equip the Creighton No. 9 shaft at their Creighton Mine proper-ty in Ontario. This paper describes the electrical and mechanical equipment used by the contractor on this project, and details various problems that were en-countered.The shaft itself is circular in section and is lined with monolithic concrete. Upon completion, it will feature twin skip compartments, a cage compartment, counterweight compartment, manway and pipe compartment. The finished diameter of this opening will be 21 feet and the shaft will bottom 7,115 feet below the collar. The present depth of the shaft (April, 1968) is 5,400 feet. The opening is concrete lined as excavation takes place and the steel will be placed in the shaft upon completion of sinking. Hoisting is done on rope guides which are part of the stage suspension system."

Jan 1, 1968

By V. K. Gupta

"Effect of mill speed on grinding kinetics has been investigated with a view to using mill speed as a manipulated variable for control and optimization of the grinding circuit performance under variable ore hardness conditions. Dry and wet batch grinding tests were carried out for quartz, limestone and cement clinker in a 29 cm x 18 cm laboratory ball mill. Mill speed values selected were 55 and 70% critical. In the case of dry grinding operation, with an exception of quartz, for all materials studied the effect of mill speed on grinding rate was found to be insignificant for sizes finer than about 35 mesh. In the case of wet operation, grinding rates were found to be approximately proportional to the mill speed. The implications of these results are discussed.INTRODUCTIONIt is well known that mill speed has a considerable effect on the grinding rate of the ore particles l-3 For particles of a given size there is an optimum speed at which mill grinding efficiency is maximum (i.e. specific energy consumption is minimum) 3•4. Mill speed can, therefore, be effectively used as a manipulated variable to deal with the disturbances arising from changes in the size and hardness (grinding rate) of the ore being fed to the grinding circuit. Though, it has not been the case so far, with recent developments of ring motors2 and frequency inverters5 a continuous variation of mill speed has now become feasible, and it is expected that mill speed control will soon be a regular feature of plant operation2,6."

Jan 1, 1985

By A. Uribe-Salas, J. A. Finch, B. J. Huls

Froth depth or interface level is an important control variable in column flotation which can influence both grade and recovery. A common method of locating the level is based on sensing the hydrostatic pressure at one or more points along the column. The level position is then calculated from these pressure readings using an equation which includes the bulk density in the froth and bubbling zones. The precision with which the level is detected depends on how well these density values represent both zones. The calculation of these bulk densities from theoretical considerations is not possible and, therefore, the practice is to estimate them by calibration. Unfortunately, the calibration parameters often do not report the level with an acceptable accuracy. A portable conductivity probe has been developed to detect the position of the interface from conductance measurements across the interface. The location of the interface corresponds to the position where a large change in conductance is observed, which is primarily a consequence of the difference in gas holdup between the bubbling and froth zones. This probe can be used to detect the position of the interface to an accuracy of± 5 cm. The probe can be used while the column is in operation, which allows the on-line calibration of the level detection system. Results obtained in its application in a pilot-scale column (0.91 min diameter) are described.

Jan 1, 1989

By Marie-Eve Boucher

The slag in iron ore pellets allows wet sintering during firing and leads to suitable bounding. The process of slag formation differs whether it takes place in the core or in the external zone of a pellet. In the core, hematite can be reduced to secondary hematite, depending on the temperature and on the carbon monoxide/dioxide partial pressure ratio. The reaction rim that appears at the outskirts of a silica particle in contact with the FeO bearing magnetite is considered as the slag precursor in the core of the pellet. By contrast, in the external zone of a pellet, where O2 is available and CO partial pressure is very low, the first step towards slag formation is flux decomposition, mainly dolomite and limestone. The CaO liberated through this reaction will be available to react with hematite by solid diffusion to form calcioferrites, which play an active part in the slag evolution process. These two slag formation paths will be explained.

May 1, 2007

By Ross Byron, Ken Roberts

"During the fall of 2001 a program was initiated to determine the feasibility of improving the metallurgy in the flotation circuit at the Penhorwood Talc Concentrator located near Timmins, Ontario. Bench scale testwork led Plant staff to believe that opportunities existed to improve the flotation performance. Pilot scale testing was then conducted using two vendors and their respective cylindrical type flotation cells to indicate where these opportunities existed.The results of the test program determined that the replacement of the existing flotation circuit (roughers, scavengers and cleaners) with new flotation cells could be economically viable. Justification was due to a reduction in installed horsepower, maintenance costs and a subsequent increase in recovery and throughput while maintaining product quality. Unforeseen benefits included reagent and air reduction, accurate level control as well as improved working conditions due to the removal of the antiquated equipment and ancillaries.This paper will detail the justification, installation and implementation of the new flotation circuit. A special emphasis will explain the hurdles encountered while trying to install and commission the circuit in an operating Concentrator with minimal interruptions to production.INTRODUCTIONThe Penhorwood mine and Concentrator is 28 yrs old and has gone through many ups and downs with different owners, Johns Manville, Steetley Talc and now Luzenac. It has also been expanded twice, with flotation and grinding capacity being added in recent years.All of the concentration is completed at the mine site while the fine grinding takes place in the Timmins micronizing plant.Luzenac’s Philosophy is to be the world leader in Talc production, technology and sales, having about 70% of the current world High Grade talc market."

Jan 1, 2004

By Don Thompson

Canada’s oil sands are a controversial topic and virtually every newsmaker and layperson seems to have an opinion about this 179 billion barrel resource. The oil sands represent 97 per cent of Canada’s remaining oil reserves, but misinterpretation and misrepresentation of the facts are threatening development of a resource that generates significant employment and tax revenue for Canadians. Join Don Thompson, president of the Oil Sands Developers Group, as he dispels the top ten myths about Canada’s oil sands and presents an alternative perspective on an industry that can play a critical role in North America’s economic recovery.

Jan 1, 2010

By Galen Bauer

"Up until the mid 1960's, the only available methods for making continuous weight measurements were through the use of mechanical and electro-mechanical weigh scales. It was during this time period that a new concept in weighing was introduced. It was known and is still known as the nuclear belt weigh scale.During the early days of its appearance in the market place, many things were learned about its advantages and disadvantages for weighing various materials. As with many new devices, it had to go through a ""wringing out stage"" before it became accepted by the weighing industry. Even today, even though it is a proven device, there are skeptics who believe the nuclear belt weigh scale will not survive. Let me assure you, it is here to stay.. 'PRINCIPLE OF MEASUREMENTThe nuclear belt weigh scale consists of a ""C"" Frame assembly which houses the radioactive source (Cesiwn 137) and the radiation detector (Ionization chamber). The ""C"" Frame assembly is put in place around the conveyor belt as shown in Figure 1. The radiation source emits a fan shaped beam of radiation which covers the full width of the material being conveyed on the belt. Radiation which has passed through the material on the belt is detected by the ionization chamber which is located in the lower arm of the ""C"" Frame assembly. The ionization chamber changes the radiation energy into an electrical signal which is related to pounds per foot belt loading. This signal is transmitted to a highly stable amplifier which combines the pounds per foot signal with a belt travel signal from a digital tachometer which allowed the scale user to be able to monitor total mass being conveyed. Many so-called conventional type scales use belt speed rather than travel to obtain mass per unit time, and then integrate the signal to obtain their weight signal. This unnecessary step tends to erode the overall accuracy of the weighing system."

Jan 1, 1975

By Emmanuel Henry

Few industries are more challenged by technical, political and market uncertainty than the mineral industry. Technical uncertainty in mining projects concerns the volume and quality of the resource, the processing and metallurgical parameters, the production efficiency, etc. Political uncertainty can take diverse forms and includes possibilities of change in the taxation system, risk of expropriation and risk of social instability or war. Market uncertainty depends on the market structure of the commodity; price and demand volatilities are the most common sources of market uncertainty. Intensive feasibility studies including these uncertainties and risks are required before investing up to billions of dollars in the development of a new mine. Current feasibility studies are often based on a single (or very few) mean geological scenario and simplified price profiles along the life of the project. Yet, strategic decisions, for example, the level of investment in exploration and metallurgical studies, adoption of a flexible, but more costly, mine design and risk-sharing strategies are made at an early stage. Over the last twenty years, Real Option theory has emerged as a unifying framework enabling strategic planning under uncertainty (technical, political and market). Geological and market variances (second order statistics) are pivotal for proper uncertainty quantification. The present study explores the possible benefits of combining modern geostatistical tools and financial techniques for project management. More precisely, the following questions are examined: Is geological uncertainty really an issue? Can we combine geological and price uncertainties in a unifying Real Option framework? A simple example aimed at illustrating the concepts involved is presented.

May 1, 2003

By Glenn K. Nolan

"Today, more than any other time in recent history, aboriginal communities are looking for ways to be understood as more resource development companies continue to explore and develop Canada's vast resource potential.Recent Supreme Court rulings have affirmed the need to engage aboriginal communities early on in resource development projects. There are many conflicting ideas on how, who, and when to engage. Given the large number of communities and varied cultures, each resource development company must equip itself with a better understanding of the people they are planning to work with.The lecture will begin with a basic historical perspective on treaties and the various societies across Canada. We will also explore the current situation many communities find themselves in today. Building a meaningful relationship with a community is the foundation for a lasting partnership. Every community is unique and every approach to engage communities must be just as unique. The lecture will outline some basic steps that can lead to a better relationship building process between the communities and companies."

Jan 1, 2008

By Kevin O?Callaghan

Applying Legal Concepts - The Crown must consult, and where necessary accommodate, when: - Crown has knowledge, real or constructive, of the potential existence of Aboriginal rights or title and contemplates conduct that might adversely affect it - Duty to consult is triggered at a low threshold - How much consultation necessary? - Proportional to the strength of claim and potential impact - Spectrum: notice to direct involvement in decision making - Not duty to agree or to get consent (no veto) - Reciprocal: Duty requires good faith and sincere engagement on both sides Role of Proponents: Crown may delegate procedural aspects of its legal duty

May 1, 2010

By R. N. Chakravorty

Early detection of spontaneous combustion is of utmost importance in underground coal mining to prevent major disruptions of production and to ensure a safer working environment. This paper presents the work done in developing a suitable system for the early detection of heating in a hydraulic coal mine. Laboratory studies on the products of oxidation for Balmer 10 seam coal showed that a significant amount of carbon monoxide is produced during the early stages of heating and that detection methods based on the analysis of other gases, such as hydrogen, ethane or ethylene, are not a better alternative for this coal. The four-point carbon monoxide monitoring system recently installed at the hydraulic mine is discussed in this paper. It is believed that by studying the trend of carbon monoxide concentration in the mine air, it will be possible to detect heating at an early stage. Field tests carried out so far have indicated that infra-red technology will prove to be a powerful tool in the hydraulic mine, particularly for locating hidden oxidation or fire in cracks, fissures, underground workings and coal outcrop areas before it spreads extensively. The project is jointly sponsored by EMR, CANMET, Mining Research Laboratories and Kaiser Resources Ltd.

Jan 1, 1978

By Karl Hoover, Cassandra Spence, Brent Bachewich, Jaakko Levanaho

"Since year 2000 the gold recovery into copper concentrate at Hudson Bay Mining and Smelting has reduced considerably during the summer months. This initiated a testwork program in the fall 2003 to find reasons and solutions for such change. During the testwork mineralogical factors, water quality effects and different reagents were evaluated. The reason for the lower recovery appeared to be the sensitivity of some collectors to pulp temperature. As a result of the work different collectors are being used in the mill in the summer than in the winter. A modification to the water system was also made to provide cooler water to the mill in the summer months.INTRODUCTIONHudson Bay Mining and Smelting (HBMS) is located in Northern Manitoba, just on the border of Manitoba and Saskatchewan. The complex consist of four different mines, Callinan, Trout Lake, Konuto Lake and 777 mine including copper smelter and zinc hydrometallurgical plants producing metallic copper and zinc. Gold is a very important byproduct providing about 30% of the mine revenue. In early 1990s when the company was facing declining ore reserves and was starting to gradually close down the operations, the 777’th exploration drill hole discovered a new orebody, which initiated a $0.5 billion expansion program. The main projects were a new 777 hoist with underground development and a new zinc cell house. About $30 million was used to increase the mill throughput to the present 2.27 million tonnes or 2.5 million short tons per year. The expansion programs were finished by the end of the year 2003.Historically the gold recovery at HBMS has varied between 60 and 70%. The recovery has been somewhat lower during the summer months. Gold recovery improvement projects were conducted throughout the 1990s, but were not focused on the seasonal gold recovery variance. However, since 2000, when the water system modifications to meet the increased water demand were completed, the gold recovery during the summer has been much lower than in the past. In August 2003 gold recovery fell below 30%, which initiated a metallurgical research program to discover the reasons behind the low gold recovery in the summer."

Jan 1, 2005