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By Rick Collins

Presentation Agenda 1.Sudbury Basin 2.Diamond Drilling 3.Planned Production 4.Safety 5.Timeline 6.Sustainable Development 7.Scope Elements 8.Progress 9.Delivery Approach 10.Owners and EPCM Roles 11.Contract Styles 12.Mine Systems & Technologies 13.Q & A

May 1, 2009

By Hamid-Reza Manouchehri

Mining & Sustainability? A Paradox?! ? Production: gradually or exponentially increasing (giant mining) ? Ore Grades: gradually declining, ? Open Cut Mining: now widespread, likely to be sustained in the future though the long-term is hard to predict as new mineral deposits are likely to be deeper ? Waste Rock / Overburden: increasing rapidly, likely to be sustained in the future and closely linked to open cut mining, especially for coal and base metals ? Economic Resources: commonly increasing but some remain stable or gradually declining, future is linked closely to exploration, technology and economics; Increasing population, changing life style and technology development, ultimately result in sustainability in mining industry to hang in the balance and continue.

May 1, 2013

By Leroy G. Hagenbuch

"IntroductionAn integrated Truck Management Information System (Truck MIS) evolves as seemingly separate functions combined to yield a single homogeneous result / product. The concept of a computer integrated Truck MIS includes truck dispatch, truck maintenance management and truck weighing.A truck management system is only as good as the information / data bases input to it. The concept of an integrated system works best with automated data gathering. Automated data gathering provides timely and normally, the most accurate historical information/data bases. Data bases are, however, historical, which is a problem to be overcome in a computerized truck management information system, especially in regards to a truck dispatch system as loading sites / loading conditions and some dump site conditions continually change. As these changes occur, data base s must change as well, and thus the need for the continual update of data bases that the computer uses for a Truck MIS.For a truck dispatch system to achieve reliability / viability, dispatch decisions need to revolve around real time data gathered in an automated way. Integration of all truck management function s through automated data gathering lead s to the best over-all system.An integrated system is a combination of many different factors and is only as good as each factor / building block put in the system. With the proper building blocks, an integrated Truck MIS is very feasible - an MIS System that includes weighing, time and motion study, truck maintenance and maintenance management, as well as truck dispatch.Truck MISAn integrated Truck MIS provides for truck dispatch as the ultimate end result, a truly automated /integrated truck dispatch system (to function non-operator-dependent). The following comprises its central building blocks:-Time.- Haul Cycle Segments.Truck Status, i.e. Load on truck,- being loaded,- loaded,- unloaded,- in service,- out of service.- Vehicle Location.Loading Equipment Status.- in service,- out of service.Optional- distance travelled in each haul segment.With this data provided on a non-operator dependent basis, it is possible to build good data bases so a computer can make truck dispatch decisions. Knowing what information is needed as the central core to a good Truck MIS, how can this information be automatically gathered and fed into a central control computer?"

Jan 1, 1986

By Donald J. Hallbom

"While pipeline hydrotransport is often the most economical way to transport large volumes of mineral concentrate, tailings, or fine ore slurry over long distances, it is in mountainous terrain that pipelining becomes particularly attractive. These areas are often remote, with limited existing infrastructure and few potential users willing to share in the cost of new infrastructure. The rugged terrain makes the construction of railways or roads suitable for haul trucks difficult and expensive. The elevation difference between the mine and the terminal means that the empty trains or haul trucks need to return up-hill, resulting in high fuel costs. With pipelines, this elevation difference may reduce or even eliminate the need for pumping. As a result, numerous pipelines have been built, or are being considered, in mountainous regions around the world including: Tasmania, New Guinea, China, Madagascar, the Rockies of North America, and the Andes of South America. However, there are technical difficulties that need to be overcome in the design and operation of mountain pipelines that do not affect pipelines on more level terrain. This presentation reviews some of these difficulties and methods used to overcome them.INTRODUCTIONPipeline transport of solid-liquid slurry (“hydrotransport”) is an important and cost-effective means of transporting large volumes of solids over long distances, especially from a single supplier to a single user (e.g., a concentrator to a port, a concentrator to a tailings dam, or a coal mine to a power plant). Pipelines are generally found to be more economically attractive than alternate transportation methods (e.g. trucking, rail, conveyors, shipping, or some combination) over the life of a project (Aude et al. 1974).Hydrotransport systems have been built in a variety of terrains, but it is in mountainous regions that pipelining becomes particularly attractive. These regions are often remote and generally do not have existing transportation infrastructure (roads, railways, navigable rivers). There are few potential users (e.g., farmers, other mines, forestry companies, etc.) who may be willing to share in the cost of new infrastructure. The rugged terrain makes the construction and maintenance of railways or all weather roads suitable for large haul trucks difficult and expensive. Mines tend to be higher than the receiving terminal (e.g. a port). This means that the empty trains or haul trucks need to return up-hill, resulting in high fuel costs. With pipelines, this elevation difference may reduce or even eliminate the need for pumping. Pipelines are easier to construct than roads and railroads in these areas for several reasons, including:"

Jan 1, 2006

By J. E. Nesset, S. R. Rao, J. A. Finch

"For base metal sulphides, iron rejection starts in mineral processing. This review focuses on changes in plant practice specifically to improve iron sulphide rejection by control of contaminant ion effects and discusses selected general innovations in mineral processing that can be expected to play a role. One group of changes to control contaminant ions is in size reduction (the use of stage grinding and inert stirred milling) and another is in system chemistry (order of reagent addition and exploitation of the flexibility of sulphoxy reagents). Plant examples illustrate the successes, indicating that there are several options available. The general innovations start by considering the new tools for measuring gas dispersion properties and quantifying froth characteristics by imaging. Examples of their application to improve concentrate quality illustrate the potential. Other innovations stress adapting geostatistics to model variation in milling and flotation response to provide feed forward control and rigorous application of statistical experimental methodology in plant test work. An example from one concentrator shows improvements in concentrate quality from application of basic principles can be impressive.INTRODUCTIONThe more iron control (rejection) that can be accomplished in mineral processing the lower the subsequent metal extraction costs and environmental implications of iron disposal, particularly in hydrometallurgical processes. Iron rejection has been a contributing target to periodic attempts to apply mineral processing to nickel laterites and bauxites but the prime application is control of pyrite and pyrrhotite (iron sulphides) in the treatment of sulphide ores by flotation. In this paper some new concepts and innovations introduced in sulphide flotation plants over the past ten years or so (i.e., since a previous review [1]) will be outlined with examples of how they have contributed to improved “iron control”.To increase rejection of iron minerals, first the recovery mechanism should be understood. There are four principal ones, two physical in origin: 1, via locked particles (i.e., flotation of composite particles due to insufficient size reduction to liberate the minerals) and 2, through entrainment in the water reporting to the float product (an unselective process); and two originating from a response to the system chemistry: 1, true flotation (i.e., iron sulphides becoming hydrophobic) and 2, as a result of iron sulphides forming aggregates with hydrophobic particles (e.g., ”slime” coatings). There has been considerable effort to diagnose which of these dominates iron sulphide recovery; in many cases it is due to “chemistry”, in particular true flotation. The flotation effect often appears related to contamination by metal ions [1]. This can reduce selectivity in two ways: 1, metal ion species may activate iron sulphides, or 2, cause general depression which demands more vigorous flotation conditions (e.g., additional collector) with consequent loss of selectivity. This is where the review will start, by considering ways to control contaminant ions."

Jan 1, 2007

By R. Gallinger

In 1997, a group of Canadian mining companies met to review the Mine Environment Neutral Drainage (MEND) program and to consider future activities. They concluded that (1) that Canadian industry and Natural Resources Canada (NRCan) should fund a small secretariat in Ottawa to support technology transfer in Canada and, (2) that it was important for industry to continue the momentum of MEND on an international scale. The need for the International Network for Acid Prevention (INAP) was strongly endorsed by consultants, company, university, and government experts from Australia, Canada, and the United States who convened in Vancouver in February 1998. The initial focus was the development of a solid knowledge base covering the collective experience of INAP?s members to promote the dissemination of successful practices, the identification of knowledge gaps, and the formulation of effective research proposals. The sharing of information on past successes and failures alone was viewed as sufficient justification for the formation of INAP. INAP was officially launched in October 1998, and is now an effective, industry-based initiative to globally coordinate research and development in the management of sulphide mine waste. Significant improvements in the management of sulphidic mine materials through knowledge sharing, research, and development of technology by INAP will reduce liability associated with acid drainage. This paper will explore the international efforts and activities of INAP

May 1, 2005

A series of fault slip seismic events have occurred at Garson mine. The events have occurred during development advancement exposing faults, after the extraction of single stopes due to mining induced stress change, and due to time effects after delays of many days during which no mining had been conducted. This paper discusses the study completed consisting of a global or holistic approach aimed at mitigating some of the risks associated with the structurally controlled rockbursts at Garson. Background Garson mine is located in the south east area of the Sudbury Basin (Ontario, Canada). Mining occurs in two main ore bodies (the #1 Shear and the #4 Shear) which are copper-nickel-sulphide and occur within shear zones that (as well as the ore bodies) strike approximately east-west and dip steeply south. From the north (footwall), lithologies progress (Figure 1a) from norite (NR), to greenstone (GS), and finally to meta-sediment (MTSD). A generally WNW-ESE striking, bifurcated sub-vertical dyke of olivine diabase (OLDI) cuts the series. The current active mining block at Garson is between 4700L and 5100L (levels denote depth in feet below surface).

May 1, 2009

By Murray Pearson, Jack Murray

"The danger of autoclaves lies in the high temperatures and pressures that exist in autoclave vessels. The usage of autoclaves will continue to expand in the mining industry because of their efficiency and environmental friendliness. But increasing attention must be paid to ensuring their safety. Safety Instrumented Systems (SISs) play a critical role in autoclave plants by detecting potentially dangerous conditions, taking the plant to a safe state, informing the operator about the plant status and the cause of the trip and expediting safe plant restart. The SIS should ideally be fully integrated with but functionally independent of the Basic Process Control System (BPCS) and provide redundant logic solvers to increase safety and plant availability while reducing spurious trips.INTRODUCTIONWikipedia defines an autoclave as follows: “An autoclave is a pressurized device invented by Charles Chamberland in 1879 designed to heat aqueous solutions above their boiling point to process materials.” A typical autoclave system used in the metallurgical industry includes, besides the autoclave vessel, heat recovery (heater) vessels, high pressure positive displacement (HPPD) feed pumps, vessel lining systems, specialized internals and components, agitators, pressure letdown or flash vessels, isolation and control valves, over 2,000 I/O points and related instrumentation, and emergency relief systems."

Jan 1, 2009

By B. M. Coombes

The McCracken and Stacey (1989) method of assessing geotechnical risk for largediameter raisebored shafts has been the basis for most Australian pre-construction raisebore investigations for the past 20 years. At the time of its publication, the McCracken and Stacey (M&S) Method did not include a database of raisebore diameter and rock mass conditions versus actual performance. It did, however, provide a chart that quantified geotechnical risk in terms of proposed shaft diameter and the raisebore rock quality index, QR. Two parameters, RQD/Jn and Jr/Ja were identified as being critical to raisebore stability, but the contribution of these to overall raisebore stability was not quantified. Peck and Lee (2008) published a database of raisebore performance from Australian case histories. Raisebore diameter and ground conditions, in terms of a Lower Bound QR value, were presented for 50 cases versus raisebore performance. This paper updates the database with further case histories and corrected SRF values. This paper further evaluates the reasons for the variable raisebore performance for similar RSR values. For all case histories, three parameters, RQD/Jn, Jr/Ja and Jw/SRF are investigated to assess their influence on raisebore performance.

May 1, 2011

By Don Peel

Mineral aggregate, the most widely used mineral resource globally, has attracted little academic or public interest. Of all mining developments, the aggregate resource is seldom factored into resource management decisions. This lack of recognition to the strategic aggregate resource has significant economic, environmental, and social implications. Impact to the economics, the environment, and the community coincide with the key elements of the United Nations concept of ?sustainable development?. To build on the concept, the mining sector contracted the International Institute for Environment and Development to assess how mining activity contributes to sustainability. As a result, a useful assessment process was developed by the Mining, Minerals and Sustainable Development (MMSD) Task Group entitled ?Seven Questions to Sustainability: How to Assess the Contribution of Mining and Mineral Activities.? In Alberta, recent opposition to mineral resource development by community residents offers an opportunity to employ the MMSD?s assessment procedure. The public opposition to the mining activity was addressed through a stakeholder planning process initiated by the municipal council of Sturgeon County, Alberta. As a result the Calahoo/Villeneuve Area Structure Plan (CASP) was formulated and adopted. To measure the effectiveness of the CASP planning process in terms of sustainability, this paper applies the MMSD?s Seven Question assessment to the Calahoo/Villeneuve Area Structure Plan.

May 1, 2004

By A. Lewis, J. Zachwieja, M. Widell, P. Zhou, W. W. Geissler, M. Svensson, A. Movahedi, H. Nordberg

Flotation collectors for sulfide minerals has been traditionally based on xanthate, thiophosphate, thiophosphinate and thiocarbamate, all derived from sulfur chemistry. Tecflote™ is a new family of patented collectors based on nitrile chemistry which can supplement or replace thiol collectors, depending on the ore types. A steep grade-recovery curve typical of Tecflote™ collectors was observed when using Tecflote™ as the main collector for the rougher and cleaner steps allowing a better recovery compared to current thiol collectors while maintaining the desired grade. Additional recovery increase has also been observed by the addition of scavenger steps using Tecflote™ collector in combination with current thiol-based collector. The selectivity seen in the lab is transferred to full scale trial and is clearly seen in the rough flotation where the increase in the rough concentrate grade of 5% after pumping Tecflote S11 directly into the tank cell. The mechanisms for Tecflote’s selectivity towards sulfides are currently under investigation and will be discussed. Results of TOF-SIMS analysis will be presented, demonstrating the collector’s selective affinity to different mineral surfaces in flotation. INTRODUCTION The history of collectors used today started in 1882 when Zeise first made xanthates. It was first used in flotation in 1925 – Cornelius Keller’s first patent (Fuerstenau, Jameson, Yoon, 2007). Between 1928 and 1930 American Cyanamid filed 7 patents for dithiophosphate, including flotation and chemical synthesis of the reagent, the first of which was filed by Christmann in 1928 (Christmann, 1933). Synthesize of thionocarbamates for mineral flotation was filed in 1954, by Dow Chemical Company (Harris, 1954). Now that the head grades have been declining over the last decades the need to find more selective collectors to extract difficult and complex ores has pushed the industry to look at different chemistries. Thiol collectors standard to the industry rely on the sulfur in the collector molecule to bond to the mineral surface. The electronic property of this group is modified by the adjacent chemical groups, such as additional S, P or N have the effect of changing the selectivity of the collector (Wills & Finch, 2016). In the case of xanthate the length of the hydrophobic group also has an effect on the selectivity with some minerals such that the ethyl xanthate is more selective against pyrite and pyrrhotite than the long chain xanthates (Wills & Finch, 2016).

Jan 1, 2019

"The first SkimAir flash flotation cell was installed in Outokumpu’s Hammaslahti Copper Concentrator in 1982 to prevent overgrinding of soft sulphides in the milling circuit. Since this first installation the popularity of the flash flotation has fluctuated depending on metal market conditions and regional preferences. Units have been installed in many commodities including copper, lead, gold, PGMs, silver and nickel. Though it has been successfully employed in many operations around the world, flash flotation technology is still not well understood by many in the mining industry. This paper will discuss aspects of flash flotation flowsheet development along with some of the metallurgical and engineering considerations required to successfully incorporate flash flotation into new or existing milling circuits. This paper will also try and debunk some of the myths that exist around flash flotation cells and their operation. Case studies of flash flotation implementation will be discussed.IntroductionModern flash flotation technology was developed several decades ago by Outokumpu, with the first commercial installation of this technology being at the Hammaslahti concentrator in Finland in 1982 (Kallioinen & Niitti, 1985). This was a relatively modestly sized SK80 cell producing final grade copper concentrate directly from the flash flotation cell operating in the grinding circuit. Since that time the size and number of flash flotation cells installed globally has grown considerably to the point where today, it is a widely known application of flotation technology for amenable ores. Owing to their long history in developing the technology, Outotec are the market leader with their SkimAir range of flash flotation cells. Though there is a general awareness of flash flotation process in the mineral processing industry, there is a lack of detailed understanding of the process and the benefits it can provide to new and existing operations."

Jan 1, 2017

By F. Ford, J. Dong

"Laboratory and miniplant testwork was carried out to reject uranium from an Iron Oxide Copper Gold (IOCG) deposit that contains an average of 60-70 ppm uranium with high variability. The dominate copper bearing mineral is chalcopyrite with minor bornite and trace covellite. The main gangue minerals are iron-rich chlorite, quartz and magnetite. The main uranium-containing mineral is uraninite (UO2). Downstream processes require the maximum uranium level of no more than 80 ppm in final copper concentrate.Mineralogical examination reveals that uraninite particles are finely disseminated with grain size of less than a few microns in the deposit requiring fine regrind in order to liberate uraninite from chalcopyrite particles. A lab flowsheet was developed to include ultrafine regrind of the rougher concentrate to the particle size of 80% passing 11-13 µm with up to four stages of recleaning in flotation columns. Finer regrind to 80% passing 5-6 µm may continue to improve liberation but does not decrease uranium level in the final concentrate. In each of the successive recleaning stages by flotation column after fine regrind, uraninite is rejected into the column tailings, with the final copper gold concentrate containing less than 70 ppm uranium from a feed containing 83 ppm uranium. The conceptual flowsheet was further tested in an integrated, continuous miniplant showing average 94% copper recovery with average 74 ppm uranium. The uraninite particles that report to the final concentrate are either locked with chalcopyrite or entrained as liberated particles of less than 5 µm in size.IntroductionIron Oxide Copper Gold (IOCG) deposits are copper and gold ores hosted within a large body of iron oxide and are significant ore deposits for copper and gold (Williams, et al., 2005). These deposits can also contain economic levels of other metals such as uranium and rare earth elements. The known sizes of IOCG deposits range from 10 to 4,000 million tonnes with grade of 0.2-5% copper and 0.1-3 g/t gold. One of the greatest IOCG deposits is Olympic Dam in South Australia. It is the fourth largest copper deposit and the largest uranium deposit in the world. Gold and silver in the deposit also contribute significantly to the total revenue."

Jan 1, 2017

By Denis Labrie

Le minage en profondeur sous contrainte modérée à élevée présente de nombreux défis aux opérateurs et aux ingénieurs de mine notamment au niveau du contrôle de terrain et de l?environnement minier souterrain, pour assurer la sécurité des travailleurs sous terre et la continuité du cycle d?opération. Des conditions de contrainte élevée signifient une pression accrue au front de taille et sur les structures minières tels les piliers de mine et les fins de zone, un risque de rupture violente ou de coup de toit plus élevé, des zones de rupture plus grandes au pourtour des excavations, des charges accrues sur le support de terrain, etc. Le présent article fournit un aperçu du travail fait à l?intérieur du Programme de Contrôle de terrain de CANMET au cours des sept (7) dernières années, entre 1995 et 2001, pour comprendre et suivre l?évolution des niveaux de contrainte à l?intérieur des structures minières. Les propriétés déterminées en laboratoire sur des échantillons rocheux et les prévisions effectuées au moment de la conception sont comparées avec les observations effectuées en chantier à la paroi des excavations et à l?intérieur de la masse rocheuse. La plupart des cas discutés ici montrent une corrélation satisfaisante entre les observations effectuées en chantier d?une part, et les résultats d?essai obtenus en laboratoire et les calculs réalisés lors de la conception d?autre part. Ces observations peuvent donc être considérées comme des moyens relativement sûrs pour vérifier et suivre l?évolution des niveaux de contrainte présents à l?intérieur des structures minières.

May 1, 2002

By Michael B. Cortie

Mesoporous gold sponge has the unique property of being both metallic and highly resistant to oxidation. It has potential application in catalysis, in bio-sensors, in optical coatings, in analytical chemistry and, as we show here, as the basis for a new kind of ultra-capacitor. Due to the cost of gold, the most probable niche for a gold-based ultra-capacitor would be in the high-power/high-energy regime, a region where gold would compete with devices based on RuO2. A high internal resistance limits the power that can be usefully drawn from existing carbon-based ultra-capacitors, and that this problem can potentially be overcome by gold-based devices. A simple proof-of-concept ultra-capacitor based on mesoporous gold is described and its behaviour during charge and discharge cycles examined. In this work a step change in the input or output voltage of the device was used as the controlling parameter. There was also a residual faradaic current resulting from traces of undissolved aluminium left over from the AuAl2 precursor used to make the sponge, and some charge storage due to polarization of the solution. Deconvolution of these three effects was not entirely accomplished, but an ostensible capacitance of about 7 to 14 mF/g Au was demonstrated. Further improvement from these early results seems likely.

Oct 1, 2003

By D. E. M. Plaumann, B. S. Fee, R. D. Hansen, R. R. Klimpel

"The steps from experimental curiosity through to commercial product can be slow and tortuous in spite of the quality of the technological advances offered by the new development. Data generation and interpretation need to be done in lab tests as well as full-scale evaluations and, in each, the advantages of the new reagent must be clearly identifiable and measurable.The Dow Chemical Company has patented a novel new collector for the flotation of zinc. Fl (2-hexylthioethylamine hydrochloride) has several unique structural features that suggest atypical mechanisms for zinc collection. Laboratory data have demonstrated significant flexibility with respect to grade and recovery balance at dosages lower than those typically used for xanthates.In mill trials, the same phenomanon is evident - the choice between high grade and high recovery allows one to select the desired quality of zinc concentrate. One trial in particular was run over a three month timeframe and Fl gave improvements in recovery of 2.5% and a reduction in lead levels with less than 0.5% loss in grade. The dosages of other reagents in the flotation circuit were also reduced.Data demonstrating improved recovery and grade in lab trials will be discussed. Extensive data from the mill trial will illustrate how Fl works in both rougher and cleaner circuits."

Jan 1, 1990

By Eric Konigsmann

"Omai Gold Mines is a large scale open pit gold mining operation located in central Guyana, South America with a 12,000 tonne per day milling facility. Mill operations were initiated in December 1992 with commercial production beginning in January 1993. The entire operation employs approximately 120 expatriates and some 800 Guyanese nationals and is expected to produce in excess of 250,000 ounces of gold per year. The total mineable reserves contain 2.5 million ounces of gold with a projected mine life of twelve years.The milling circuits feature an SABC grinding circuit, gravity concentration and a conventional CIP gold recovery circuit. This paper will review the mill start up and ""run-in"" phase during the first year of operation. Emphasis will be placed on descriptions of start up problems and circuit modifications, mill performance trends in 1993, and personnel training and development. An outlook for 1994 is also given.IntroductionOmai Gold Mines is a large scale, open pit gold mining operation located in the Potaro district of Guyana, South America, some 160 kilometers south of the capital city Georgetown. Although there are numerous small scale gold mining ventures in Guyana, particularly with the dredging operations on the rivers, Omai is the first hard rock, open pit mine to be developed in the country. At present, this mining operation is one of the largest gold mines in South America.The Omai gold deposit has been exploited for over one hundred years. In the late 1800's, a German syndicate used hydraulicing with subsequent gravimetric separators such as sluice boxes and trommel screens to recover gold from saprolite, a soft, oxidized, claylike mineral which covers much of the claim area. Through the early 1900's and up until the 1950's, numerous mining companies including Anaconda Mining Co. Ltd. explored and drilled the Omai deposit but the technology and low gold price of the day made the reserve uneconomic to develop."

Jan 1, 1994

By Ahmad Ghahreman, Lin Li

Silver and cupric ions have been proven to play the roles of catalysts to promote the oxidation kinetics of chalcopyrite in acid solution. In this study, the interaction between silver ions and cupric ions during ferric leaching of chalcopyrite in sulfuric acid solution has been investigated. The electrochemical study by Tafel analysis showed a significant boost of dissolution rate for chalcopyrite dissolution in Fe3+- Cu2+ containing sulfuric acid solution after Ag+ was added in the solution. For 10 ppm Ag addition, the dissolution rate of chalcopyrite increased to 7.94 ×10-6 A/cm2 from 3.2 ×10-7 A/cm2, when Ag+ was absent. On the other hand, the effect of Cu2+ on the dissolution of chalcopyrite in Fe3+-Ag+ containing sulfuric acid solution was not obvious from electrochemical measurements. The chalcopyrite leaching tests in different acid solutions showed that silver addition had an obvious catalytic effect on promoting chalcopyrite dissolution. Comparing the leaching rates of chalcopyrite leached in Fe3+ containing, Fe3+-Ag+ containing, Fe3+-Cu2+ containing and Fe3+-Cu2+-Ag+ containing sulfuric acid solutions, it was found in Ag+-Fe3+-Cu2+ containing sulfuric acid solution, the leaching rate was highest among all the aqueous acid systems. Further leaching tests suggested that with increase of the Ag+ concentration from 0 to 20 ppm, the leaching rate of chalcopyrite in Ag+-Fe3+-Cu2+ containing sulfuric acid solution also increased and reached 57.62% with 20 ppm Ag+ addition after 24 h. INTRODUCTION Chalcopyrite is the most important copper mineral in copper hydrometallurgy and it accounts for nearly 80% of the universal copper resource (Olvera, Rebolledo, Mora, Dixon, & Asselin, 2018). The hydrometallurgy of chalcopyrite has been intensively studied with emphasis on solving the slow dissolution kinetics of chalcopyrite in acid environment. A variety of aqueous systems, such as sulfate (Hiroyoshi, Miki, Hirajima, & Tsunekawa, 2001), chlorides (Liu, Chen, & Yang, 2017), and ammonia (Hua et al., 2018) have been studied to improve copper leaching. From another perspective, chalcopyrite leaching studies have indicated that the mechanism of chalcopyrite dissolution in acid solution is essentially electrochemical (Li, Kawashima, Li, Chandra, & Gerson, 2013). Therefore, extensive studies have recently been carried out to explain the dissolution kinetics of chalcopyrite in different media by various electrochemical techniques.

Jan 1, 2019

By A. H. Marquis

Since the start-up of its first Direct Reduction Module in April 1973, S1DBEC has produced over 2 million tons of prereduced iron. During this period, SIDBEC has acquired comprehensive experience in the operation of the direct reduction process and at the same time has learned to recognize the characteristics that the oxide should have to constitute an adequate feed for the process. A comparison is made as to the design and operation of the two direct reduction units now operating at Contrecoeur, Que. A description is given of a method of evaluation of a direct reduction unit, which takes into account the main process variable sand which permits comparison ofthe results on a daily basis. The paper defines the characteristics that the iron oxide and the prereduced iron pellets must have to meet the specific requirements of the direct reduction and the electric arc furnace processes. A simple model makes possible a rapid evaluation of the technical and economic effect related to the use of a given raw material. Finally, the paper outlines the advantages of prereduced iron in the steelmaking process and on the quality of the steel products.

Jan 1, 1979

By T. Gammatikopoulos, C. Gibson, M. Aghamirian

Lithium is an alkali metal found in brine deposits in the United States, Chile and Argentina, as well as in hard rock deposits in Australia and North America. In hard rock deposits, spodumene (LiAl(Si2O6)) is the major economic lithium bearing mineral. Spodumene is typically upgraded through a combination of dense media separation, flotation and magnetic separation. One of the major spodumene concentrate quality specifications is the iron oxide content because it will help determine if the concentrate is considered ceramic grade for use in ceramics and glass or chemical grade for use in lithium ion batteries. The rejection of iron bearing silicate minerals from artificial ore composites (high amphibole and low amphibole, high quartz/feldspar) from a hard-rock spodumene deposit was investigated using magnetic separation and flotation. The efficacy of Wet High Intensity Magnetic Separation (WHIMS) in iron rejection was found to be dependent on the mineralogy of the iron-bearing silicate minerals including modal distribution, liberation and association. When magnetic separation was conducted prior to flotation, the Fe2O3 grade in the final flotation spodumene concentrate was reduced from ~3% to ~1% Fe2O3 , and improved lithium recovery in flotation was observed. It was determined that it was most effective to conduct WHIMS on the flotation feed after scrubbing and de-sliming because this reduced the required magnetic field to recover iron-bearing minerals, likely because slime coating was greatly reduced. Flotation collector screening of four different collectors with varying rosin acid content demonstrated a potential increase in selective flotation of spodumene over some iron silicate minerals with decreasing rosin acid content in the fatty acid collector. However, due to marginal difference in flotation results with the various collectors tested, further testing is required to confirm the observations made and establish a hypothesis regarding the effect of rosin acid content.

Jan 1, 2017