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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 Adam Moore, Ryan Gillespie, Jarrett Quinn, Audrey Walters, Peter Radziszewski

"Vale Long Harbour Processing Plant (LHPP) was designed to process Voisey’s Bay nickel concentrate into finished nickel and associated copper and cobalt products. The plant includes a secondary grinding circuit comprising two Stirred Media Detritors (SMDs) operating in parallel. The ultrafine grinding circuit was designed to process concentrate at a rate of 33 t/h and produce a ground product (P80) of 20 µm to feed the leach circuits. Start-up of the grinding circuit at LHPP was undertaken in December 2014.The objective of this paper will be to describe the design, commissioning, start-up and performance of the secondary grinding circuit with a focus on the two Metso SMD-355-C mills. Following a brief overview of Vale’s LHPP and the SMD technology, the paper will review the design of the SMD secondary grinding circuit from lab tests through to scale-up performance prediction. This will be followed by the results of circuit commissioning outlining some of the issues raised and addressed after which SMD performance will be outlined. Specifically, the SMD circuit grinding performance will be examined since start-up which will include the effect of media size and wear on grinding. Furthermore, impeller wear will be examined by determining initial “shear volume” and worn “shear volume” as well as its effect on mill power and the means to maintain it. The paper closes with a discussion on grinding performance."

Jan 1, 2016

By D. Knuutila, G. Goyette, James A. Finch, G. Bartolacci, A. Fortin, Chi Ho Lau, A. Lockhart

"In a COREM-McGill collaborative research and development project, gas dispersion parameters and froth properties were manipulated in a copper flotation plant to study interactions between the collection and the cleaning zones. In this paper, specific work on developing some relationships between operating conditions and froth stability in a rougher column flotation cell of 125 m3 is reported. Froth stability, measured by image analysis, was related to the following process conditions for specific flotation machines in an industrial case study: Gas flow rate, collector dosage, pH, frother type and dosage. Across the range examined, froth stability was improved through a decrease in gas flow rate and/or increasing frother dosage. Metallurgical results (grade and recovery) showed that both gold and copper were dependent on froth stability.INTRODUCTIONMcGill and COREM have over the past two years collaborated in a research and development project to merge gas dispersion parameters, frother analysis (McGill technology), and froth properties (COREM’s imaging system) to study the interactions between the collection zone (pulp) and the cleaning zone (froth). The main goal is to increase knowledge of flotation cell hydrodynamics since it is known to govern the metallurgical performance of the flotation process (Power et al., 2000). In this paper, specific work on developing some relationships between operating conditions and froth stability in a copper flotation circuit is reported.The objective of this work is to study gas dispersion in a large volume flotation column (hydrodynamics) and to measure its impact on the froth. By froth imaging, it is possible to diagnose operational problems on the basis of froth characteristics (Bartolacci et al., 2005a) and consequently, to propose ways of improving process performance by froth analysis (Bartolacci et al., 2005b).Another approach to froth characterization is investigated in this paper. In the same flotation column, a froth stability apparatus (column) was included (Triffet and Cillers, 2004). The mechanical froth stability apparatus is used to link “hard” froth characteristic measurements to “soft” froth characteristic measurements (those obtained by imaging)."

Jan 1, 2008

By T. Ivankina, T. Lokajícek, H. Kern, T. Svitek

The knowledge of 3D velocity distribution of P- and S-waves in rocks is very important parameter for interpretation and understanding the nature of seismic anisotropy observed in the earth’s crust and upper mantle. A new high-pressure measuring head was designed and constructed to enable ultrasonic sounding of spherical rock samples in 132 independent directions under up to 60 MPa of acting hydrostatic pressure by means of simultaneous longitudinal and transversal sounding. New measuring system enables ultrasonic sounding of spherical rock samples by using a pair of P-wave sensors and two pairs of perpendicularly polarized S-wave sensors (TV and TH) see Fig.1. Shear wave sensors polarization is oriented according to rotation axis of the sample. Special shear wave gel was used to transfer shear waves between the sample and sensors under acting hydrostatic pressure. An isotropic glass sphere was used to check and calibrate the new measuring setup. A spherical sample of a biotite gneiss from the Outokumpu scientific drill hole was used for testing measurement. There is shown that both, P- and S-wave velocities, can be measured simultaneously up to 70 MPa, respectively. We report data of the 3D velocity distribution of P- and Swaves measured for the first time on a sample sphere of biotite gneiss. We rely, in particular, on the directional dependence of compressional and shear wave propagation and their relationship to the crystallographic (CPO) and shape preferred orientation (SPO) of major rock-forming minerals. The 3D seismic measurements revealed a strong foliation-related directional dependence (anisotropy) of P- and Swave velocities. Ultrasonic measurements were compared with 3D velocity calculations based on neutron diffraction measurements of crystallographic preferred orientation (CPO) of major minerals. Comparison of 3-D velocity distribution (P, S1, S2 and S1-S2) determined by two completely different methods ultrasonic sounding and neutron diffraction is presented. Measurements showed that the intrinsic bulk anisotropy is basically caused by the CPO of biotite constituting about 23 vol.% of the rock.

Jan 1, 2015

By S. Hoskins, S. Chiovelli

"The annual budget for the repair and maintenance of equipment at Syncrude Canada Ltd. is in excess of $450 million. Of this amount, a significant portion can be attributed to the loss of material on various pieces of equipment throughout the operation. In order to effectively battle the different wear and corrosion mechanisms that lead to material loss, it is important to understand how materials behave in the environments in which they are used. Through the work carried out at Syncrude, and work conducted with various external collaborators, significant improvements in both equipment reliability and productivity have been achieved. This paper will review some recent field trials where materials research has demonstrated the potential for significant improvements in equipment run life and reduced maintenance costs. These field trials will demonstrate the need for understanding the interaction between various damage mechanisms and the materials used in different services. The paper will also discuss current areas of focus along with future directions for further work. IntroductionSyncrude Canada Ltd, located in northern Alberta, Canada, operates a mining, extraction, and upgrading facility that removes bitumen from oil sand to produce synthetic crude oil. Oil sand is mined from the orebody using conventional open pit mining techniques. Recently, the mining scheme has changed from a dragline/bucketwheel/conveyor system to a shovel/truck/crusher/hydrotransport operation as depicted in Figure 1. Since the start of production in 1978, the identification, development and application of wear protection has been an ongoing challenge due to the abrasive nature of the oil sands and the massive volumes of materials that are moved. The use of various materials and application processes along with component design modifications has resulted in significant improvements in both productivity and reliability (Adamic et al., 1995; Llewellyn, 1996, 1997; Anderson et al., 1998; Chiovelli et al., 1998).In an effort to continuously improve the operation, Syncrude has been quick to adopt new wear technologies. As seen in Figure 2, since the start of operation, a variety of materials have been used to increase wear performance and ultimately equipment reliability and availability. Although Figure 2 does not show a time axis, the bottom axis may also be used to represent a time progression for the predominate use of these materials at Syncrude. Tungsten carbide metal matrix composite (WC-MMC) overlays are currently the materials of choice for most of Syncrude’s critical production applications. Metal matrix composite overlay technology has potential for significant improvements and Syncrude is actively working with powder consumable manufacturers to advance this technology."

Jan 1, 2004

"In conjunction with Banick Mercur , Wright Engineers Limited designed the first multi-stage aqueous pressure oxidation system in an alkaline environment in North America. A three-stage slurry heating and slurry pressure let-down with heat recovery was an innovative approach to the problem of high energy cost with the low sulphur content of the ore. The design of this system required solving a number of problems associated with heating and pumping of slurries at pressures up to 3230 kPa and temperatures in excess of 220°C. Wright received an Award of Merit in October 1989, from the Canadian Consulting Engineering Awards Committee in the Process Category for its design of the Mercur pressure oxidation system.The Mercur Mine is located at the south end of the Oquirrh Mountains in Tooele County about 65 miles by road from Salt Lake City, Utah, U.S.A. The original mill was designed to process 5000 tpd of oxidized gold ore in a carbon-in-leach (CIL) circuit. A new ore treatment system was required to treat the substantial quantities of refractory ore reserves which could not be treated economically in the existing mill. The new pressure oxidation circuit makes the refractory ore amenable to gold recovery by oxidation of the sulphides contained in the ore .Wright Engineers Limited was commissioned by Barrick Mercur Gold Mine Ltd ., a wholly-owned subsidiary of American Barrick Resources, to design the pressure oxidation facility. This followed completion of a feasibility study by Wright which showed that the project was technically and economically viable.Work on the feasibility study began in 1986, detail design commenced in February 1987, and was completed in December 1987. Mechanical installation was completed in January 1988, and slurry feed began in February 1988. The plant has operated since June 1988 without major interruption . Wright was responsible for engineering, procurement and construction management for the addition of the 750 tpd pressure oxidation circuit to the existing mill and also had commissioning responsibility.Major unit processes involved in the pressure oxidation facility are ore thickening, three-stage slurry preheating, pressure oxidation and three-stage slurry cooling with heat recovery, stearn generation, propane and oxygen storage and a video graphic display process control system were included in the scope as process anciliaries.The pressure oxidation increases gold recovery from the refractory ore by conventional CIL from as low as 35% to more than 86070. A patent has been granted for the process."

Jan 1, 1989

By Derrin A. Auerswald, Jacolien P. Wyethe, Nanne M. \/egter

Base and precious metal refineries often produce effluent solution and slurry streams containing between 50 mg/L and several grams per liter of base metals. Metals have historically been precipitated from these streams with lime to produce effluent streams at pH values between 8 and 9. This effluent treatment process generally does not remove alkali and alkali-earth metals or halides efficiently and with more stringent environmental legislation, more sophisticated effluent treatment plants must be considered which could for example incorporate sulphate removal with ultra-filtration, or the SavminTM process, followed by reverse osmosis for the removal of halides. The flowrates of effluents are often high and if base metals can be recovered before neutralization, the revenue generated from this stream can reduce the cost to produce clean water significantly, and in the case where high concentrations are disposed of, result in a profitable operation. As an add-on to an existing the plant the recovered metal is upgraded and recycled to the plant, but the production of a saleable metal can also be considered. Technology selection for metal recovery depends on the composition and flowrate of the effluent, but could incorporate resin-in¬pulp or other ion-exchange technology; precipitation as sulphides, hydroxides or carbonates; or solvent extraction. This paper describes, as a case study, the technology selection process and uses data from Zincor. Zincor is a division of Exxaro Base Metals (Pty) Limited, a subsidiary of Exxaro Resources Limited.

Jan 1, 2011

By J. W. Matousek

"Computer modeling of smelting processes requires internally consistent equations for calculating the compositions of mattes and slags. That is, the sum of the calculated assays must total 100%. One set of equations that satisfies this requirement for copper produced under oxidizing conditions (pSO2>one atmosphere pressure) is given by the following:%[Fe] = 62.0 – 0.775%[Cu]%[S] = 28.0 – 0.00125%[Cu]2%[O] = 10.0 – 0.225%[Cu] + 0.00125 %[Cu]2Mattes containing nickel in appreciable quantities do not have the defined “white metal” end point of approximately 80 percent copper and 20 percent sulphur that is found in the copper system during the converting process. The above equations, however, are readily extended to nickel and nickel/copper mattes for any desired end product composition."

Jan 1, 1996

By D. Nikols, G. Caraghiaur, P. C. Roxburgh

"IntroductionThe Highvale Mine is located 70 km west of Edmonton , Alberta on the south side of Lake Wabamun. It has been developed by TransAlta Utilities Corporation as a captive mine to supply fuel to two genera ting power plant s. The mine is owned by TransAlta and operated under contract by Manalta Coal. Within the mine permit area, TransAlta own s the right to mine 80% of the recoverable surface mineable coal.The planning process starts with the annually produced 25-year energy forecast which is provided by the Electric Utility Planning Council (EUPC). A 1983 forecast predicts an average annual increase in energy requirements of 4% over the next 25 years. Put another way, the requirement will double before the end of the century. A lar ge part of the base load generation of the Province of Alberta is provided by th e plants fueled from Highvale Mine. The Highvale Mine is therefore expected to maintain a high output over a long period of time.Mine PlanningMine planning is an ongoing, interative process that draws from many sources. All levels of planning draw from the same sources but du e to the different processes and objectives of each planning class, the degree of influence may differ. The planner becomes then a coordinator bringing together data and excerpts from several disciplines in groups. Generally, there are four classes of mining plan s; these are all used at the Highvale Mine (Table I)."

Jan 1, 1986

By J. A. Meech, R. J. Tucker

"A dynamic computer model has been developed to simulate the operation of ore crushing plants. The model was created in a general form to allow imitation of a wide variety of secondary crushing circuits with only minor program modifications. The system can be run on either a microcomputer or a large time-sharing main frame computer as required.The size reduction and separation characteristics of crushers and screens are based on standard manufacturers' design and performance data. These calculations are isolated within various subroutines to facilitate tailoring of the model to emulate any particular plant of interest. Input and output data are presented in a variety of formats. Crusher, screen and conveyor amperages and surge bin levels can be presented in a tabular form along with appropriate alarms arising from improper circuit operation or process interruptions. Graphical representation of the circuit together with strip chart data output are features of the system when operated in a microcomputer environment.The program is currently being used at Queen's University as a teaching aid to demonstrate plant operating characteristics, control strategies and design concepts. The acceptance of, and reaction to the program at this level indicates a good potential for it to provide a valuable tool for operator training."

Jan 1, 1985

By Robert B. Parsons

"Canada's mining industry has reason to celebrate the federal government's budget which was tabled on February 26, 1986. The budget contains an important proposal to improve the flowthrough share rules by effectively eliminating the investor's liability to third parties. This proposed rule change and other important budget proposals are the subject of this month's edition of Tax Notes. IntroductionWhile Finance Minister Michael Wilson's February 26, 1986 budget received a mixed reaction from business and labour leaders, the budget was mainly ""good news"" for the mining industry. A long-standing bugaboo in the flow-through share rules will be cleared up, a permanent set of rules will be installed for the tax treatment of Northern allowances, and limited partnerships will apparently be able to continue to serve a useful role in financing exploration programs. Flow-Through SharesThe present rules which apply to an investment in flow-through shares are structured in such a way that the relevant Canadian exploration expense (""CEE"") must be incurred by the investor, and not by the issuing corporation. Obviously, in the case of most flow-through share issues, this requirement that the investor incur the CEE poses a practical problem-the investor typically does not have the expertise or organization to incur the CEE. As a result, an integral part of most flowthrough arrangements is an agreement whereby the investor appoints another party (usually the issuing corporation) as his agent to spend the flow-through funds on CEE on his behalf. Although the issuing corporation might consequently be the party which actually spends the flow-through share funds on CEE, nevertheless the legal structure is such that the investor is the ""principal"" who is incurring the CEE. As such, the investor is legally responsible for any third-party claims with respect to the exploration program. Third-party liability might arise, for example, in the case of property damage, personal injury, environmental infractions, and so on."

Jan 1, 1986

By J. D. R. Neilsen

The objective of the research conducted and presented herein was to determine the effect of pre-established free gas saturation on the sweep efficiency of an isolated inverted five-spot well pattern. The investigation concluded that the ultimate recovery of an isolated inverted five-spot may be slightly increased by establishing a free gas saturation prior to water flooding; however, of more significance is the extreme deviation of the pattern's performance after water break-through from that commonly obtained from developed well patterns. The rapid "water-out" characteristic common to both linear floods and floods conducted in developed well patterns was not evidenced in the isolated inverted five-spot. Instead, the wells continued to produce oil long after breakthrough until ultimate areal sweep efficiencies of four, five, and six hundred percent were obtained prior to the water-oil ratio becoming excessive.

Jan 1, 1962

By J. Jung, W. Keller, N. Rohn

In hydrometallurgical minerals processing slurries are often processed at very small grind sizes and high solids concentrations. This normally results in flow anomalies of such slurries. Due to flow limits or yield stress the slurry tends to stagnate close to the vessel bottom, the walls and at any internals. The main mixing task therefore generally is not suspending of the solids but the homogeneous blending of the entire vessel volume. If not considered during the agitator design only a fraction of the vessel contents will be mixed. Therefore the knowledge of the slurry rheology as well as the variations in process parameters is vital to design e.g. storage or surge tanks. The integral mixing solution considers the motor power, the choice of the impeller type and number, the impeller diameter as well as the design of the baffles and feed and discharge positions.

Jan 1, 2014

By Z. Manafi

Bioleaching of a copper sulfide ore containing "activated pyrite", using a mixed culture of mesophilic bacteria, was studied. This type of copper ore had been found unsuitable for flotation because it produces a concentrate containing relatively high iron concentrations and, therefore, a low copper grade. Microscopic observations showed that pyrite particles had been activated by the formation of a thin film of chalcocite. Hence, a bioleaching process was considered as an alternative to treat this ore. Following shake flask and acid consumption tests, column tests of the crushed ore (75% -12.5 mm) were initiated and the effects of culture medium, agglomeration, and irrigation type on copper recovery were studied. The results showed that all the columns containing bacteria had copper recoveries around 90% compared to the abiotic control column with a recovery of 50%. It was concluded that bioleaching could be successfully utilized to process copper ores containing activated pyrite.

Jan 1, 2007

By Doug Russell

Natsource: At a Glance l 160 employees l Global reach ? New York, Washington, Calgary, Ottawa, Toronto, London, Tokyo l Major Environmental Commodity Broker ? Rated as Top GHG Broker (Environmental Finance Magazine Survey, Dec. 2000 & 2001) ? Leading RECs Broker ? Large Broker of SO2, NOx l Large Energy Broker ? One of Highest Volume Gas Brokers ? Major Electricity Broker Overview l International Market l Implementing the Rate-Based Proposal l Assessment and Management of Risk from GHG Emissions Limitations

Nov 1, 2002

By Vladimir N. Rudashevsky, Louis J. Cabri, Nikolay S. Rudashevsky, Thomas Oberthür

"EPD (Electric Pulse disaggregation) and HS (hydroseparation) are exceptional technologies for research, concentration, evaluation, and mineral extraction of specific minerals such as precious metals (Au, Ag, PGM), kimberlites (extraction and concentration of indicator minerals), zircons and baddeleyite (recovery of objects for geochronology), and even gemstones (method of evaluation and production of the 100% gemstone concentrate of ideal crystals) etc. EPD is used for recovery of pristine undamaged crystals of diamond, emerald, ruby, sapphire etc, including large crystals. It was tested on various hard ores and was especially successful for recovery of “soft” minerals from “hard” matrix. EPD products are very convenient for HS processing, resulting in representative concentrates of all heavy minerals including the finest particles (5-10 µm). The combined EPD and HS method enables high sensitivity (20 ppb) for evaluation of precious metal ores providing objective information about original grain size, associations, and recovery using a very small amount of sample (1-3 kg). Latest developments of EPD and HS techniques at CNT Mineral Consulting Inc. include the HS-21 hydroseparator (50 kg/hr) and the Spark-21 EPD (5 t/hr), which enables use of both techniques for prospecting and mineral processing of industrial size samples of certain ores.INTRODUCTIONThe main task for mineral processors is to find a reliable technology for testing of mining feasibility and the efficiency of mineral extraction procedures. Among various mineral processing approaches of extraction and concentration there are two alternative cost-effective methods that can be described as the most environmentally benign and complementary: electric-pulse disaggregation and hydroseparation. These techniques were tested on many different ore types and process products with great success providing a precise and comprehensive mineralogical determination of different accessory precious metal and other useful minerals constituent in rocks, ores, and tailings.This article describes several examples of EPD and HS use: native gold from the Kostomuksha deposit (Karelia, Russia), a Ag-Au deposit in South America, zircons from ancient ultramafic igneous rocks of SW Greenland, bauxites of West Australia, PGM from the Driekop dunite pipe and gemstones (ruby, sapphire, emerald and demantoid) from different deposits."

Jan 1, 2008

By R. A. Hill, J. D. Pitts

"Long distance slurry pipeline systems have been successfully trans-porting steam coal, iron concentrates, copper concentrates and limestone for an aggregate of nearly 60 years and nearly three billion ton-miles annually. A phosphate concentrate pipeline is nearing start-up and systems for coking coal, lead/zinc concentrates and fly ash are planned. The solids pipeline concept, first patented in the early 1900's and commercialized in the 1950's, is now a proven technology providing an economic, environmentally pleasing and safe method for long distance bulk transport.The challenge for larger tonnage and longer distance movements of solids, for traversing increasingly rugged terrain in grass roots mineral developments, for transporting untried materials and for shipping more economic forms of proven materials still remains. This has necessitated continued refinements and optimization of the technology. The economic and environmental incentives for slurry pipelines when compared to other transport alternatives has justified substantial activity in this area. The scope of planned systems in coal, iron and other minerals is indicative of the firm place slurry pipelines will have in worldwide mineral development.In this presentation, the state-of-the-art in long distance slurry pipelines is reviewed with a focus on major systems of interest to the mineral processing industry. An overview of new developments in the application of this concept is presented, and finally, a projection of the future of pipelines in mineral development both worldwide and in Canada is discussed."

Jan 1, 1978

"The Key Lake mill was commissioned in 1983 to process the two Key Lake ore deposits. With the depletion of these ore bodies in 1999, the plant was converted to mill the exceptionally rich McArthur River deposit located seventy eight kilometers northeast of the Key Lake mine site. This paper describes in detail the Key Lake milling process. The mill consists of a grinding circuit, a leachkounter current decantation circuit, a solvent extraction circuit, a yellowcake precipitatiodcalciner circuit, an ammonium sulphate crystallization circuit, and a waste treatment circuit. The paper also describes process changes to handle McArthur River ore, including the ore receiving stationLOCATIONThe Key Lake mill is located 78 kilometres south of the McArthur River mine. It is located at latitude 57' N in northern Saskatchewan, within the southern boundary of the Athabasca formation. The nearest town is Pine House, located 240 kilometres to the south. Access to the mine is by an all weather road and by a private airstrip.HISTORYAND DESCRIPTION OF OPERATIONThe Key Lake mill was commissioned in October 1983 to process ore from the Gaertner and Deilmann ore bodies. The mill was designed to produce twelve million pounds of uranium oxide (U308) a year from a feed grade of 2.4% U3O8.Following grinding, the uranium is leached in a two stage leach circuit using oxygen and sulphuric acid. An eight-thickener counter current decantation (CCD) circuit is used to separate the uranium bearing solution from the solid waste residue. The uranium is further purified in a solvent extraction circuit and then precipitated using ammonia. It is then calcined at 840' Celsius, and packaged into drums for shipping to refineries. There is a crystallization circuit to recover ammonium sulphate produced in the process and a waste treatment circuit."

Jan 1, 2001

By M. Remillard, M. Garon, D. Hodouin, M. Therien

"Nineteen streams in the copper and zinc flotation units of the concentrator of the Matagami Division of Noranda Inc. have been sampled f or particle size distributions, chemical assays, and gold and silver contents in each particle size interval. The data are upgraded by the mass balance package BILMA T. These results, in conjunction with microprobe analyses, are used to quantify the silver losses in the copper cleaning flotation stages and to determine how over-all silver and three silver-bearing minerals are recovered in the plant final products. RESUMEDix-neuf produits des circuits de flottation du cuivre et du zinc de la division Matagami de Noranda Inc. ont été échantillonnés pour leur distribution granulométrique, leurs analyses chimiques et Ie contenu d'argent et d'or des fractions granulométriques. Le bilan métallurgique a été obtenu à l'aide du programme BILMA T. Ces résultats, couples avec une étude minéralogique a fa microsonde, sont utilisés pour quantifier les pertes argentières aux diverses étapes de nettoyage du circuit de cuivre et pour déterminer la répartition de l'argent et des trois minéraux argentifères dans les produits finals de l'usine."

Jan 1, 1988

By K. Torigoe, S. Owad, C. Tokoro, Y Tsunazawa

The mechanism of an abrasion process to recover metal values by removing components from printed circuit boards (PCBs) is modeled using a discrete element method (DEM) simulation. To simulate the abrasion process, a model PCB geometry was constructed consisting of bonded particulates. The simulation allowed connections between particles to be broken if the bonding force calculated from DEM exceeded a threshold level. Simulation results were compared with experimental comminution data using an agitation mill with test PCBs on which nine capacitors were surface solder-mounted. Simulation results obtained from the DEM with the anchoring model corresponded to experimental observations.

Jan 1, 2011