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By Tapio Leskinen

"In the 1960’s, when large flotation machines appeared on the market, this was a part of a world-wide trend towards the use of ever larger machine units.One factor that has played a decisive part in this development is the increased of the amounts of ore that have to be handled as the exploitation of successively poorer ores becomes necessary. The advancing application of instrumentation and automation has worked in the same direction.In 1970, a working group was set up within Outokumpu Oy, for the purpose of flotation machine development. The principal task of this group was to be the design and development of- a new type of rotor of increased efficiency, especially for the dispersion of large amounts of air- a mechanical-pneumatic flotation machine of substantially larger size that existing plant.This development project required an extensive program of theoretical investigation and experimental studies at several concentration plants of the company.The commonest flotation machine presently used in the concentration plants of Outokumpu Oy is the VK-3. It is of the mechanical-pneumatic type, and the volume of its cell tanks is 2.5 m3 per shaft. This machine was developed within the company, and its first development phase i s represented by the OKKO 3, built for the Kotalahti concentrator in 1959. It was, in its time, comparable in volume to the largest machines that were then in use anywhere in the world."

Jan 1, 1976

By A. Cabañas

"In this paper, geostatistical techniques are applied to forecast the annual copper price in the short and medium terms (from one to five years ahead). These techniques allow the incorporation of monthly and multivariate information in the analysis and provide more accurate results than traditional approaches, especially as far as the one-year forecast is concerned.A second advantage of geostatistics stems from its ability to assess the uncertainty associated with the unknown future prices, thanks to estimation variances or confidence intervals, depending on the technique used. Such an assessment has a crucial importance in decision-making, from both macroeconomic and microeconomic points of view. IntroductionThe copper price traded in the London Metal Exchange is a relevant parameter for defining macroeconomic policies of producing countries like Chile. It is also a key factor for the mining companies, since fluctuations in the sell price affect the expected financial flows. Due to the amount of money involved in decision-making, it is necessary to have accurate forecasts of the future copper prices and to quantify the uncertainty associated with such prices.This paper focuses on the annual copper price estimation in the short and medium terms, i.e., from one to five years into the future. Henceforth, the word “estimation” will be used as a synonym of “forecast,” according to the geostatistical jargon (Matheron, 1989).Two main approaches, based either on statistics or econometrics, are currently used to forecast commodity prices, but both of them are not very accurate when applied to copper. First, the main methods are briefly reviewed, then the geostatistical formalism will be presented. So far, the latter approach hardly has been used to estimate commodity prices, although it may reconcile both statistics and econometrics via (1) the use of a stochastic approach and (2) the handling of ancillary variables related to the copper market. Another advantage of geostatistical techniques is the ability not only to forecast the copper price, but also to measure the uncertainty associated with it."

Jan 1, 2004

By M. Schmidt, P. Nord, M. Larinkari

Cathode stripping machine technology has been developed significantly both in electrorefining (ER) and electrowinning (EW) applications in the last ten years. The main driver has been robotic cathode handling, which has enabled increased flexibility to meet different layout and material handling requirements for both ER and EW processes. Additionally, cathode stripping stations have been continuously developed to optimize speed and to reduce mechanical stress of permanent cathodes. 'taco' type cathodes have been proven as beneficial approach for high capacity operations (particularly in Cu ER), where over 600 cathodes per hour continuous throughput has been achieved. However, the latest developments also apply to split type cathode stripping. Besides material handling, the modern cathode stripping machine has also an important role to provide information for production and quality monitoring. This paper describes the latest developments from the field of copper cathode stripping based on several different projects implemented in the recent years. INTRODUCTION After introduction of the permanent cathode technology in the late 1970s, it became the prevailing technology in copper refineries over the traditional starting sheet process by the end of 1980s. The main driver was less labour-intensive production due to fewer processing steps required along with more automated electrode handling equipment (cathode stripping machine, anode preparation machine, anode scrap washing machine and tankhouse cranes). Since then the design of the cathode stripping machine has followed the development of permanent cathode technology. The main development steps so far can be summarized as follows: Full Deposit Stripping Machine (FDSM) based on waxed permanent cathodes or cathodes with bottom edge strips resulting in split cathodes (copper sheets separated, see Figure 1) Wax less cathode stripping based on V-groove on bottom of the edge strip resulting in either ‘taco’ cathodes (enveloped copper sheets, see Figure 1) or split cathodes Full Deposit Robotic Stripping Machines (FDRSM) using 1–5 robots for permanent cathode handling and cathode stacking.

Jan 1, 2019

By D. J. Hutchinson, M. Lato, M. Diederichs

Light Detection and Ranging (LiDAR)-based applications for geomechanical purposes have recently proven to be a highly reliable and accurate form of remote analysis and documentation. The ability to remotely collect, process and evaluate rockmasses for structural geomechanical applications has benefits ranging from safety to efficiency, and provides a permanent record that can be assessed before and after an excavation has been completed. With the collaboration of Queen’s University and Rio Tinto, the Iron Ore Company of Canada (IOC) mines in Labrador City, Newfoundland and Labrador, evaluated the practical application of the I-Site 4400 LiDAR equipment, in conjunction with the Vulcan geotechnical module for geomechanical purposes. The project provided a comparative analysis between conventional hand-mapping and digital analysis. The analysis indicates that digital mapping could be employed as an active tool within the general geotechnical workflow, where results would be used in pit wall and rockmass support designs. As well, the field work enabled the generation of effective operational guidelines and protocols to maximize scanning efficiency.

Jan 1, 2009

The information in this document has been prepared as at February 16, 2011. Certain statements contained in this document constitute ?forward-looking statements? within the meaning of the United States Private Securities Litigation Reform Act of 1995 and forward looking information under the provisions of Canadian provincial securities laws. When used in this document, the words ?anticipate?, ?expect?, ?estimate?, ?forecast?, ?will?, ?planned?, and similar expressions are intended to identify forward-looking statements or information. Such statements include without limitation: statements regarding timing and amounts of capital expenditures and other assumptions; estimates of future reserves, resources, mineral production, optimization efforts and sales; estimates of mine life; estimates of future internal rates of return, mining costs, cash costs, minesite costs and other expenses; estimates of future capital expenditures and other cash needs, and expectations as to the funding thereof; statements and information as to the projected development of certain ore deposits, including estimates of exploration, development and production and other capital costs, and estimates of the timing of such exploration, development and production or decisions with respect to such exploration, development and production; estimates of reserves and resources, and statements and information regarding anticipated future exploration; the anticipated timing of events with respect to the Company's minesites and statements and information regarding the sufficiency of the Company's cash resources. Such statements and information reflect the Company's views as at the date of this document and are subject to certain risks, uncertainties and assumptions, and undue reliance should not be placed on such statements and information. Many factors, known and unknown could cause the actual results to be materially different from those expressed or implied by such forward looking statements and information. Such risks include, but are not limited to: the volatility of prices of gold and other metals; uncertainty of mineral reserves, mineral resources, mineral grades and mineral recovery estimates; uncertainty of future production, capital expenditures, and other costs; currency fluctuations; financing of additional capital requirements; cost of exploration and development programs; mining risks; community protests; risks associated with foreign operations; governmental and environmental regulation; the volatility of the Company's stock price; and risks associated with the Company's byproduct metal derivative strategies. For a more detailed discussion of such risks and other factors that may affect the Company?s ability to achieve the expectations set forth in the forwardlooking statements contained in this document, see the Company's Annual Report on Form 20-F for the year ended December 31, 2009, as well as the Company's other filings with the Canadian Securities Administrators and the U.S. Securities and Exchange Commission. The Company does not intend, and does not assume any obligation, to update these forward-looking statements and information. Marc Legault, a Qualified Person and the Company?s Vice-President, Project Development, reviewed the technical information disclosed herein. For a detailed breakdown of the Company?s reserve and resource position see the February 16, 2011 press release on the Company?s website. That press release also lists the Qualified Persons for each project.

May 1, 2011

By Paul J. Cascone

This paper will discuss the science behind the development of a unique gold alloy for dental prosthetic applications. The alloy (GOLDTECH BIO2000) contains 99.7% gold providing unquestioned biocompatibility and unsurpassed esthetics. The topics discussed are: (1) How the alloy meets the functional requirements of a porcelain-fused-to-metal dental alloy. (2) How the alloy color affects the esthetics of the restoration and why the color of gold is best. (3) Overcoming the intrinsic malleability of gold when grinding the alloy surface. (4) Preventing the oxide color from interfering with the alloy esthetics. (5) Attaining excellent porcelain adhesion. (6) How the design of the restoration allows for the production of single and multiple unit restorations. Gold 2003

Oct 1, 2003

By N. Wang, A. I. A. Salama

"An index to evaluate the amenability for processing of different coals is implemented. The index is based on the well-known Mayer-curve or M-curve. The index is superior to other existing indices and is implemented using Microsoft-Excel™. Several coals are used to demonstrate the implementation of the index proposed.IntroductionIn 1950, Mayer introduced a curve that carries the information embedded in the fir s t three curves or ash curves of the conventional washability tables and curves (Peng et al., 1979; Osborne, 1988). The curve was labeled the Mcurve (abbreviation for Mittlewertkurve in German or the Mayer- curve). The main idea behind the curve is to use the ordinate for the cumulative mass and the abscissa for the ash (attribute) mass. Specific slopes on the resulting curve represent the cumulative float, cumulative sink, and elementary ash (attribute) contents (Mayer, 1950, 1953, 1957; Venkatesan, 1975; Osborne, 1988; Salama, 1989). Beyond the ash values, the curve carries graphical information that can be used in evaluating coal processing characteristics. Consequently, it becomes possible to present several raw coals on a single diagram, thus making it easier to compare their processing characteristics. This is particularly useful in comparing various size ranges of raw coal or the same size range from different seams. Therefore, the M-curve is adopted as a vehicle for developing the “processing (washing) characteristics index” implemented in this paper."

Jan 1, 2001

By K. Turgeon, J. -F. Boulanger, L. Whitty-Léveille, C. Bazin

"Several companies targeting Rare Earth Elements (REE) around the world have completed a Preliminary Economic Assessment showing positive project financial results. Although REE ores may contain high REE value, financing these projects remains difficult in part due to the number of processes required to valorize the elements and the relatively low yield of these processes. Direct ore leaching without the production of a concentrate may reduce the capital and some operating expenditures through process simplification, and increase revenues because of REE recovery improvement.A silicate REE ore is used to test various hypotheses regarding whole ore processing and to develop a simplified flowsheet. An atmospheric leach (200 kg/t H2SO4) of crushed whole-ore containing 0,6% REE, followed by impurity removal and REE precipitation recovers 80% of the REEs in a solution containing REE and Th. The high value contained in most REE deposits makes whole-ore approaches worth considering for most projects, given the losses of valuable species typically associated with the production of a REE mineral concentrate from the ore. INTRODUCTIONRare Earth Elements (REE) find applications in modern and clean technologies, whether civil, industrial or military. With China producing more than 90% of the world’s REE, the embargo imposed by this country in early 2010 increased REE prices for a three year period. With prices having shrunk back many-fold from their peak value, projects put forward during the hike are struggling to secure financing. Owing in part to unconventional processes such as acid-baking and solvent extraction, REE plants are high capital cost and high operating-cost units, and present technological risks (Verbaan et al., 2014)."

Jan 1, 2016

By H. U. Ross

"INTRODUCTION Extensive studies have been carried on pure gold to determine the various factors that affect its dissolution in alkaline cyanide solutions. With the extension of milling to refractory ores more intensive investigations on the effect of impurities in the ore on the dissolution kinetics are needed. The present work describes experiments carried on refractory flotation tailings with the object to determine how the recovery of gold could be increased. The effect of arsenic and antimony in the ore and the excessive use of lime are discussed. Control of cyanide losses is also dealt with.MECHANISM OF THE GOLD DISSOLUTION REACTION In aqueous cyanide solutions, gold is believed to be dissolved by one of the following reactions:4Au + 8NaCN + O2 + 2H20 = 4NaAu (CN)2 + 4NaOH (1)2Au + 4NaCN + 2 + 2H20 = 2NaAu (CN)2 + 2NaOH + H202 (2)2Au + 4NaCN + H202 = 2NaAu (CN)2 + 2NaOH (3) The first of these, known as the Elsner Equation is supported by )4 3,2,1(several authors while others(5,6) support reactions 2 and 3 known as the Bodlander Equations. According to Habashi(7), the overall reaction for the dissolution process is as shown in equation 2. Most of the workers agree that hydrogen peroxide is produced in the course of the reaction."

Jan 1, 1973

Block caving is an underground mining method for the profitable extraction of massive, low-grade orebodies. Lately, it has become the mining method of choice, for many mining companies, because of depleted high-grade orebodies, and declining metal market prices. Block cave mining, however, still faces several challenges. Lack of access to the cave remains a major issue in understanding the rockmass response to mining for method optimisation. Improving our understanding of the rockmass response to caving will lead to safer and more productive operations. Combining large datasets from multiple sources with virtual reality scientific visualisation (VRSV) is a viable alternative to understanding complex cave behaviour without access to the cave. This is achieved using immersive environments with the ability to view complex multi-dimensional data (beyond 3D) graphically. VRSV offers a unique platform where it becomes possible to immerse the multi-disciplinary experts, and/or management team, in a virtual mine environment for quick decision making and fast resolution to conflicting conclusions. The underground mining system is complex due to multiple interrelating factors such as geology, excavation geometries, stress and time. Block caving is even more complex than most underground mining methods due to the network of tunnels required, and the use of induced stress, among others. As a consequence of the complexity in the block caving environment, it is vital that the mining system is analysed holistically, as a system, rather than optimizing individual factors one at a time. This paper presents a customised software module developed for use in the Advanced Visualisation Interactive Environment (AVIE) at The University of New South Wales (UNSW), Australia, to enable VRSV investigation into block cave mining systems (BCMS). This approach has the potential to provide a better understanding of the effect of time in in rock engineering, which has proven to be an important factor in hard rock mines (Ma & Daemen, 2006; Malan et al., 1997; Suorineni, 2010) but never validated. This work back analyses the early undercutting phase of a case study block caving operation with the view to understanding time/sequence effects. There is evidence that heterogeneous rockmass time-dependent behaviour governs the seismic response of the rockmass following undercut developments.

Jan 1, 2015

By C. Gosselin, G. M. Payenzo, C. Bazin, M. Desnoyers, G. Chevalier

"ArcelorMittal Mines Canada operates hydraulic classifiers to reduce the silica content of an iron oxide concentrate from 4.5% to less than 1.2% SiO2. Sampling campaigns were conducted to develop a preliminary model for the hydraulic classifier. Results show that iron oxide and quartz are respectively concentrated in the coarse and fine size fractions of the classifier feed. The mineral partition curves in the classifier and the size distribution of the minerals in the feed are used to simulate the classifier operation in order to identify the source of variability observed in the daily plant production data. Results indicate that most of the variation is probably caused by unsteady operating conditions of the classifiers.INTRODUCTION Hydraulic classifiers are a class of gravity separation devices (Wills, 1992) used to classify particles according to their size and specific gravity. Hydraulic classifiers also known as density separators (Hearn, 2002) combine hindered settling and upward flow of water to selectively entrain light particles to an overflow stream. Denser particles settle to an underflow stream. Hydraulic classifiers are used for various purposes ranging from cleaning of coal (Das, Sarkar, & Mehrotra, 2009), recovery of chromite from plant tailings (Kumar, Tripathy, & Rao, 2009) to upgrading iron oxide concentrate (Hearn, 2002). ArcelorMittal Mines Canada operates several hydraulic classifiers to upgrade an iron oxide concentrate by removing fine quartz and other light minerals from hematite that is the main iron oxide mineral. A project was initiated to analyze the operation of the classifier in an attempt to identify the source of the variability in the production results and to assess the potential of increasing iron recovery in the classifier. One possible disturbance for the classifier operation is the change in the classifier feed composition and size distribution, while the other considered disturbance is the operation of the classifier. The paper is divided into five sections. The first section summarizes the ore processing sequence for the production of iron oxide pellets to identify the position of the hydraulic classifier in the process. The second section describes the hydraulic classifier. The third section discusses the sampling campaigns conducted on the hydraulic classifier. The method used to process the data from sampling, the results of the data processing and simulation of the classifier are discussed in the remaining sections."

Jan 1, 2012

By D. Laguitton, D. Hodouin, V. K. Gupta, R. Spring

"The CANMET SPOC project aims at inducing progress in process evaluation and optimization by developing user oriented software based on state-of-the-art theory. The present work is the result of a joint effort by CANMET, Noranda Mines and Université Laval to develop two computer packages: one (RTD) to calculate the residence time distribution that best describes the material transport through the mill, the other (FINDBS) to estimate the rate of breakage and distribution function of the population balance model in a ball mill. The RTD package can handle data from various experimental methods (impulse or complex tracer feed, with or without recycling, etc...). The FINDBS package provides options for the functional description oj both model parameters Band S. The full detail of the methods and programs appears in a users guide. The program capabilities and several sample runs are presented.IntroductionSimulation of mineral dressing operations by computer has been largely contained within academic and research circles and has not yet gained a status of routine practice in the ore and coal industries. It is however a matter of time before process simulators are available on every process engineer's desk to assist process optimization tasks, flowsheet design and professional training. The CANMET SPOC project (Simulated Processing of Ore and Coal) was initiated in 1980 to assist the Canadian industry in integrating computer-based methodology for process evaluation and optimization(1). Software development, documentation and transfer is one of the main priorities of the project which will mature in 1985 by releasing a complete package of manuals and programs covering sampling, material balance computation, unit modelling, flowsheet simulation and optimization . This paper is a condensed description of a typical project element in its 1982-1983 state of development. The required methodology for ball-mill modelling and simulation was consolidated an d merged to other project elements during a joint study under contract financed by CANMET and Noranda Mines Ltd . The first part of the study dealt with documenting experimental methods and software for ball-mill computer simulation. Université Laval GRAAIM (Goupe de Recherche en Automatistion Appliquée à l'Industrie Minérale) acted as sub-contractor for this part of the study(16,17). A second part dealt with applying the model calibration techniques to a large industrial data base and is reported elsewhere(2,18,19)."

Jan 1, 1984

By Mark Kennedy, Allan MacRae, Cameron Hams

New technology projects, particularly those involving first-of-a-kind metallurgical facilities, have a poor track record of achieving their overall financial targets, as they incorporate technological risks in addition to normal project risks. Traditional project management tools focus on risk from concept development through implementation, but typically fail to address the additional risks associated with a new technology project including slow start-up, slow ramp-up, and failure to achieve design performance (quality or throughput). These additional risks affect future cash flows produced by the project and hence its value, typically measured as net present value (NPV) or internal rate of return (IRR). Common accounting practice is to reduce the present value of future cash flows by applying a chosen discount rate, often reflecting the corporation's cost of capital. This discount rate does not contain an allowance for technological risk, which is often underestimated or misunderstood by both the financial and engineering project managers. This paper will focus on the topic of project risk and new technology, and how these play a role in the probability of achieving the predicted future cash flows. By properly addressing technological risk in the form of risk-weighted returns, marginal projects can be prevented from proceeding, while sound projects can be given the additional time and resources required to achieve the optimal level of front-end-loading (the level which returns the maximum risk-weighted net present value). A simple set of mathematical tools should enable engineers and financial professionals to establish a common level of understanding, thereby leading to a more accurate assessment whether a new technology project is ready to pass through its next level of approvals.

Jan 1, 2011

By Jonathan Peck, Jim Gray

"While the mine developer looks for bigger and better orebodies in countries offering lower risks to development capital, the opera-tor of existing mines is looking for bigger and better ways to use his existing resources. Mining operations today utilize a variety of stand-alone systems for planning and managing their operations. In both small and large mines, payroll, accounting, inventory, planning, and engineering requirements are met using a combination of manual and computer-based systems.Technical advances and new enabling technologies are changing how mines are doing business. PC-based systems are allowing small operations to join the larger mines in using advanced computer-based systems. Advanced monitors are being used in maintenance to track, predict and correct the health of production equipment. Production monitoring systems are used to measure the performance of operating equipment and personnel in real time. This detailed information on how much, where, when, and by whom is being used for proactive management and planning. Ultimately, this information can be used to optimize and control the machines’ activities, eventually leading to robotic and autonomous operation of mining equipment.As the use of technology increases in mining, specific information objectives are being met but other problems are being created. The life cycle of technology is small, and as current systems are replaced by newer ones, integration problems and additional end-user training are created. In addition, onboard monitoring systems can create large volumes of data, data which are frequently archived without being analyzed. Mine operators are also duplicating efforts applying new technologies in an effort to be more competitive, but in doing so are creating interfaces which are only compatible with their own facilities. As system development moved from the centralized mainframe computer to the PC environment, the fragmentation of these systems became more pronounced.To efficiently continue in adapting and utilizing advancing technology, the mining industry needs to develop a system architecture that readily integrates as many sub-systems as possible. This will provide a framework for existing system integration and design guide-lines for future development. The Total Mining System (TMS) concept will allow a network of stand-alone functional modules to be readily integrated with minimal effort. This paper will discuss some of the current technologies cur-rently in use in some surface mine operations.In addition, a description of the information system and communications requirements that will be needed to integrate these components in the future, will be discussed."

Jan 1, 1996

By Yasser Mohamed

Daily field management of earthmoving operations requires quick and regular decisions for allocating available equipment to different jobs on a project. A general foreman?s day starts with matching several activities with a suitable set of available equipment to achieve the highest productivity and lowest unit cost. Usually, this decision-making process needs to be quick, and depends to a great extent on the foreman?s experience, which varies from one individual to another. Many analytical solutions with various degrees of sophistication and optimization exist to address such decisions. However, adopting any of these solutions is contingent on how accessible and easy-to-use the solution is. This paper discusses the development process of a webaccessible solution for evaluating earthmoving fleet composition and allocation scenarios. The solution relies on discrete event simulation and an optimization backend engine, but introduces the user with a simplified and easy-to-use interface that is accessible from any mobile device, and is customized to specific user?s needs. The developed system gathers most equipment and site-related input data from a company?s information systems to minimize user input. The user mainly needs to formulate equipment and job combinations and allocation scenarios (e.g. soil type, quantity, and hauling distance), according to equipment availability each day. Then the system will evaluate the productivity and unit cost estimates for each scenario, allowing the user to choose the most suitable one. It may also be used to automatically recommend the optimum solution given an available list of equipment. The paper presents the process followed in prototyping the proposed system in collaboration with a major Canadian earthmoving contractor, and customizing it to the user needs within the company. It also describes the overall structure of the developed system and its core simulation model.

Aug 1, 2013

By Tassos Grammatikopoulos, Sarah Prout, William Mercer, C. Gunning

"The Nechalacho rare metal deposit is located in NWT, Canada. Avalon Rare Metals Inc. is now evaluating processing techniques for recovery of REE to be used in the industry. QEMSCANTM analysis coupled with whole rock, REE, Zr and Nb, and electron microprobe analyses were utilized to identify and quantify the mineralogy of the deposit, and define the REE distribution among minerals. QEMSCANTM mineralogy was performed on fifty intact drill samples using EXPLOMINTM that provided textural information for the mineralization; crushed samples were used to determine the variability of the ore and define REE domains, and composite samples to determine the liberation and association of the REE minerals. The sample matrix predominantly consists of biotite, feldspars, quartz, muscovite/clays, minor chlorite and amphibole, magnetite and hematite and carbonates. REE include in decreasing order of abundance allanite (3.6%), monazite (1.5%), synchysite (0.9%), columbite (0.9%), fergusonite (0.6%), bastnaesite (0.4%), and zircon 11.0%. The majority of the HREE are carried by fergusonite and zircon, and the LREE by monazite, allanite, synchysite and bastnaesite. QEMSCANTM mineralogical data is extremely valuable in assessing the mineralogy of the ore. The data have been implemented in defining the mineralogy of the ore body, support metallurgical test work, predict recoveries and grades, and finally calculate reserves of the deposit.INTRODUCTIONAvalon is in the unique position of owning and developing one of the world’s largest rare earth deposits in the Northwest Territories of Canada.The term Rare Earth Elements (REE) is used to describe the 15 lanthanide elements or metals and, more recently, the metals yttrium and scandium, which display similar physical and chemical properties. REE are not particularly rare and have a similar abundance in the earth’s crust to nickel, tin or tungsten. Unlike these better known metals however, the rare earths have little tendency to become concentrated into commercial ore deposits. When they do become concentrated, deposits of REEs usually display enrichment in one of two groups. The most commonly occurring deposits of REEs contain a sub-group of elements referred to as the “light rare earth elements” (LREEs), which include lanthanum, cerium, praseodymium, neodymium, and samarium. Less commonly, deposits of REEs contain the much more valuable sub-group of elements referred to as the “heavy rare earth elements” (HREEs), which include europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium. Yttrium and scandium most commonly occur in association with this second HREE sub-group. Generally, LREEs are produced from the mineral bastnaesite, and the HREEs have been produced from the minerals xenotime and monazite. LREEs continue to be produced from bastnaesite, however in the 1980s, China started production of HREEs from unique laterite clay deposits. China now produces approximately 95% of the world’s rare earths."

Jan 1, 2011

In this paper, geostatistical techniques are applied to forecast the annual copper price in the short and medium terms (from one to five years ahead). These techniques allow the incorporation of monthly and multivariate information in the analysis and provide more accurate results than traditional approaches, especially as far as the one-year forecast is concerned. A second advantage of geostatistics stems from its ability to assess the uncertainty associated with the unknown future prices, thanks to estimation variances or confidence intervals, depending on the technique used. Such an assessment has a crucial importance in decision-making, from both macroeconomic and microeconomic points of view

Sep 1, 2004

By John G. Payne

The Pebble deposit contains three contiguous zones. In the Pebble West zone, granodiorite stocks intrude gently warped volcanosedimentary rocks that had been intruded by diorite sills and two felsic intrusion breccias. In the Central zone, volcanosedimentary rocks are cut by diorite and granodiorite sills; the latter are genetically associated with the granodiorite stocks. In these zones, widespread potassic alteration consists of brown biotite and K-feldspar, with abundant quartz-carbonate-sulphide vein stockworks. Chalcopyrite/pyrite ratios range from 2/1 to 1/20. Diorite hosts the highest-grade mineralization, with much of it being disseminated. Patchy, later phyllic alteration is moderate and commonly depleted in copper. The Pebble East zone occupies a granodiorite stock and intruded host rocks below an eastwardly thickening wedge of barren Tertiary volcanic and sedimentary rocks up to 600 m thick. Brown biotite alteration and copper mineralization are strong, with chalcopyrite/pyrite ratios commonly over 1/1. The zone extends to a depth of at least 1200 m below surface; some drill holes bottomed in strong mineralization. Later, weak to moderate sericitic alteration removed some chalcopyrite and locally remobilized gold. The Pebble deposit has a Measured/Indicated resource of 3 billion tonnes grading 0.28% Cu, 0.32 g/t Au and 0.015% Mo (= 0.5% copper-equivalent) and an Inferred resource of 1.13 billion tonnes grading 0.30 g/t Au, 0.27% Cu and 0.015% Mo (0.55% copper-equivalent). The Pebble East zone has an Inferred resource of 2.13 billion tonnes grading 0.55% Cu, 0.34 g/t Au, and 0.037% Mo (0.97% copper-equivalent). The Pebble East zone is open to the east and to a lesser extent to the north, south, and to depth.

May 1, 2006

By Erwin L. Zodrow

"The neglect of including the toxic metal mercury in the list of escaping elements (Zodrow, CIM Bulletin, September 1982, pp. 138-140) was pointed out to the author in a private letter by J.E. Rehder, dated September 21, 1982. I welcome this opportunity to present my preliminary mercury research data based on coal investigations supported by N.S.E.R.C and the University College.As mercury is a volatile element and liquid at room temperature, special analytical techniques are required to determine concentrations in whole coal. In the investigation, the coal is analyzed by flameless atomic absorption with a lower detection limit of approximately 10 parts per billion, which, however, is a function of the ash contents of the coals (personal communication, J.L. Brooker, XRAL, 1981).Coal seams of the Sydney Coalfield studied so far include: the Point Aconi, a thin shaly coal, the Upper Bonar, an overrider of the Harbour seam, and the Harbour, Shoemaker and McAulay seams, all of which are shown in stratigraphic succession in Figure 1. The seams have been channel-sampled taking 15-cm coal intervals as one sample for analysis. One channel sample has been investigated from each of the seams listed (two channels were taken from the Point Aconi seam), resulting in 38 samples. Table 1 shows the results, which include mercury contents, ash and total sulphur per sample interval. Figure 2 is a frequency distribution of the 38 determinations."

Jan 1, 1982

By Louise H. Michaud

Albian Sands Energy is scheduled to begin production at its oilsands operations in the fall of 2002. Start-up includes the selection and implementation of over 75 IT systems or computer applications. These include engineering applications, systems required to control mining activities, maintenance, the processing plant and utilities, and also systems required to run the company, such as human resources, finances and inventory/warehousing. This paper outlines the processes used for the selection, implementation and integration of these systems in order to optimize the use of information and to meet the technical, business and IT requirements of the company. The first step in Albian?s approach to identifying system requirements is the development of a Business Activity Model, outlining all tasks involved in running the operations. The computer applications required to accomplish each task are then identified by having the IT team work closely with each technical and business unit. Historically, at some companies, the selection of systems has been lead by the IT team or by consultants, with little input from the technical or business units. Typically, this results in products that don?t meet the company?s expectations. To ensure a more positive outcome, Albian believes that it is imperative that the company?s technical and business people are closely involved in the selection process. Integration of the IT systems is also key, including linking all applications through a Data Warehouse and EDMS. Over 120 required integrations have been identified. This ensures the storage of all data in only one location, data security, and easy data and document retrieval for all requirements throughout the company.

May 1, 2002