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By Claude Deveau

"Studies on the performance of Falcon batch type concentrators treating ultrafine tantalum at Tanco have revealed that very fine heavy minerals are concentrated within certain areas of the concentrate bed. This information led to the design of a bowl which would allow entrapped lighter low grade particles to escape while providing more space for heavier particles to be recovered in the bed.Numerous tests were then completed with a modified batch-type and non-fluidized Falcon bowl in which the diameter of the discharge lip was adjusted downward manually in steps. This allowed for the gradual building of a higher grade concentrate bed.This work ultimately led to the design of a new Falcon with an automated continuously variable lip. In April 2005, Tanco commissioned the first Falcon UF600.This paper will discuss laboratory scale results and also plant performance of the Falcon’s UF technology.INTRODUCTIONTantalum Mining Corporation of Canada, also known as Tanco, is a wholly owned subsidiary of Cabot Corporation based in Boston, Mass. Operating since 1969, the underground highly mechanized room and pillar operation produces tantalum, lithium and cesium minerals and is located a 2 hour drive east-northeast of Winnipeg Manitoba, Canada.At Tanco, tantalum is recovered using conventional gravity concentration, enhanced gravity concentration and flotation. This paper will discuss how the need for improved equipment to treat very fine tantalum particles was filled by a machine which was modified to the point of creating a completely new technology.In November 2003, Tanco began the investigation for the potential use of a high g-force smooth walled concentrator for treating ultra fine tantalum produced by its flotation circuit. Until then, the tantalum flotation concentrate had been treated by a circuit which consisted of a Mozley Multi-Gravity Separator 902 (MGS), a Mozley MGS 900 and a Bartles cross belt concentrator. Through QemScan analysis, it was found that the majority of the losses from this circuit were of an extremely fine nature which exceeded the recovery limits of equipment on hand. Mean particle size of the tantalum losses was less than 10 µm."

Jan 1, 2006

By H. E. Urtubia

"BHP-Billiton’s Minera Escondida Limitada, in Chile, is one of the world’s largest copper producers. It treats a combined 10,500 tph of copper ore through its two concentrators: Los Colorados and Laguna Seca. The performance of the rougher circuit at each concentrator was measured and analysed using the JKTech flotation optimisation methodology. This involved developing a flotation model for each concentrator based on cell operating parameters (for example bubble surface area flux and froth recovery) and feed ore floatability characteristics. The rougher circuit performance was evaluated in terms of traditional measures, such as grade and recovery. The operation was also analysed using the measured cell operating parameters and ore floatability and the effect of these with regard to performance (grade / recovery) was assessed.This paper presents a comparison of the rougher circuit at each concentrator in terms of these parameters. The main differences in rougher circuit performance between the two plants were attributed to differences in feed ore floatability characteristics and froth recovery. The comparison highlighted opportunities where performance improvements could be made. The study also showed the usefulness of separating the flotation process into easily measurable subprocesses to further identify the different mechanisms occurring in each rougher circuit. Traditional measures like grade and recovery are useful for monitoring flotation operation but this data lacks the depth to determine the root cause behind operational issues. Determining the operating parameters and ore floatability provides the operating plant metallurgist better tools to assess and manage these issues."

Jan 1, 2006

By A. Dave Mackintosh

In 2001, at the CIM AGM in Quebec, a paper discussing poor ground conditions in a newly opened area at Agrium?s Vanscoy Potash Operation?s, suggested load transfer around old workings as a possible reason for the early room failure. High closure rates are expected in deeper regions however the rapid failure of walls immediately behind the face resulted in protective guards being mounted on and behind the borer. The high closure and early rib failure continued well past any reasonable distance to be explained by load transfer around old workings and investigations continued into possible reasons other than simply depth. Detailed investigations into the mineralogy and crystal fabric of the ore zone provided one possibility, which combined with a changed borer cutting profile are now believed to have contributed greatly to the poor conditions.

Apr 1, 2005

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 Jérôme Girard, Shiu Kam, Sue Longo

"Historically, tailings management in a northern climate has involved the deposition of tailings into the Tailings Management Area (TMA) as conventional slurry. This type of system is obviously viable but presents challenges that are difficult to manage as circumstances change over the life of mine. These issues can include:? Increases in mill throughput, and? Life of the TMA for the life of mine.This case study will present how thickened, high-density, non-segregating tailings are used as an alternative to conventional slurry disposal to achieve greater storage capacity and enhanced environmental performance for a gold tailings facility in a northern climate. This paper will focus on how this change in deposition strategy accommodated the increased throughput of the mill and the increased life of mine. Specifically, the paper will discuss the addition and integration of new processes to the exiting mill system to accommodate the tailings management issues. It will highlight the challenges from laboratory testing to pre-feasibility to the engineered design of the thickened tailings system implemented at Musselwhite Mine.BACKGROUNDGoldcorp Canada’s Musselwhite Mine, in Northwestern Ontario (120 km north of Pickle Lake), is an underground gold mining operation that began production in 1997. The current mill throughput is about 4000 tpd (1.4 Mtpa). Gold extraction is based on a CIP process with cyanide destruction.The existing tailings management area (TMA) is located about 2 km southwest of the mill complex. The TMA is contained by high ground to the north and to the west and flanged by a moraine ridge along the south side. A number of dams have been constructed along this ridge. The dams were first built in 1996 and subsequently raised in 2000 and again in 2005. Excess tailings pond water is discharged to a polishing pond then released to the environment via a wetland.The TMA was originally designed to contain 13.7 Mt of tailings under a ponded surface for closure. The water cover was to inhibit adverse long-term environmental effects because the tailings contain pyrrhotite and other sulphide-bearing minerals that are potentially acid generating. The design was modified during Stage 3 Construction in 2005 to expand the storage capacity to 17.3 Mt (Golder, 2005). As of end of 2009, over 16 Mt of tailings had been deposited in the TMA. The slurried tailings were historically deposited at 50% solids."

Jan 1, 2011

By Shahram Tafazoli

This article presents a novel technology for sensing the size of rocks after blasting in hard rock mines. Blast engineers require rock size statistics to carefully adjust the blasting parameters. The rock fragmentation requirements vary depending on the ore type and crusher specifications. The most popular statistical parameters in the industry are the so-called P numbers (e.g., P80 and P100). A machine vision based system is introduced here for automatic image collection and fragmentation analysis of the material right inside the bucket or dipper of mining shovels. A heavy-duty camera provides the required imaging data to an embedded computer mounted inside the cab. A custom machine vision software continuously analyzes the captured bucket images and stores the suitable ones in local storage which are then fed to a Desktop software for automatic fragmentation analysis. This technology has been developed by Motion Metrics International and is commercially available as FragMetrics?.

May 1, 2009

By Lloyd Rowson

??Several factors have led to a review and reoptimization of the Midwest uranium deposit by AREVA Resources Canada Inc., the project operator, on behalf of the owners ??The current proposal is to mine the deposit using open pit methods and then transport the ore by truck on a dedicated road linking the Midwest site with AREVA?s McClean Lake Operation (JEB mill) for processing ??A decision has been made to begin mining the deposit by 2010 (pending regulatory approvals)

May 1, 2008

By Roberto Busato Belger

- Fertilizer Business Overview - Supply -Demand Balance in the World - Supply -Demand Balance in Brazil - Brazilian Market Growth Opportunities - Fosfertil Operations - Fosfertil Expansion Plan - Salitre Project - Project Characteristics - Technical Challenges and Solutions - Technical Support Studies Conclusions

May 1, 2010

By Brian Hart, Stamen Dimov

"The Time of Flight Secondary Ion Mass Spectrometer (ToF-SIMS) is unique in that it measures the outermost atomic layers of any material. The technique is particularly suited for determining surface chemical composition of mineral particles. It is most commonly used as a diagnostic tool to measure mineral surface chemical variability in plant and bench top flotation separation processes. Recently, research towards understanding the full capability of the instrument has resulted in the development of new diagnostic applications related to various Au extraction technologies and the development of the ToF-SIMS as a predictive tool for assessing the chemical reactivity of the ore.In this paper we will present a brief review of the ToF-SIMS technique with recent advances in instrumentation and methodologies including:•,?recent developments and advances towards a semi-quantitative approach to the evaluation of mineral surface modifiers (ex. Cu),•,?flotation case studies investigating activator, depressant and collector loading variability within a flotation process,•,?the recently developed chemical reactivity test which we believe has the potential to predict the behaviour of minerals in a flotation test in response to chemical transfer during grinding,•,recent applications for determination of surface Au preg-robbed in carbonaceous materials.A portion of this material has been recently presented at the COM 2009 meeting and at SIMS XVII (see Dimov et al 2009 and Hart et al, 2009).INTRODUCTIONIn flotation seperation surface chemistry is the principal determinant for selective separation of the various mineral phases (Ralston, 1994, Smart et al, 2003). Determination of this hydrophobic/hydrophilic balance by particle therefore requires correct identification and selection of the particular mineral phase(s) followed by a statistical analysis of the surface chemical characteristics of the particles with an estimation of the spread of values (Smart et al, 2003)."

Jan 1, 2010

By Constantin D. Pitis

Similarly to notions of constant capital/expenses in business or magnetization power for electric motors an energetic base load (E0) is always necessary to set up a mining process. Denominated as ?non-productive energy? or base load, (E0) is a constant component of the entire energy consumption of the process, while another component the ?productive energy? (Ep) is variable, being function of the production/throughput (M). By using these new concepts, the author creates an energetic model proposing a new method of assessing changes in mining processes (throughput) that can reveal possible energy savings (DSM component) or energy losses. Proposed mathematical model of assessing (E0) and energy savings by using ?Marginal Energy Usage Index? (MEUI) enables creation of historical benchmarks and direct on line energetic (efficiency) assessment of mining processes and/or equipments. The paper analyses the case of assessing possible energy savings that can be obtained by: ?? Improving efficiencies of various equipments (by retrofit) ? reducing E0 ?? Improving the process control or other process changes ? reducing Ep ?? Monitoring persistence of the adopted Energy Conservation Measures (ECMs). For the new plant design, the proposed method enables prediction of Customer Baseline in various mine/process configurations. The method could become part of a ?preventive action? in design process by offering a reliable tool of assessing additional financial effort (Incremental cost) when choosing various higher efficiency equipments and/or processes.

Oct 1, 2009

By Mani Manimaran, Inna Dymov, Mariam Melashvili, Chris Fleming, Joe O’Day

This paper presents experimental evidence that supports the use of bromine/bromide as a potential alternative to conventional cyanidation for gold leaching. The study evaluated a brominebased lixiviant, Stabilized Bromine, with considerably lower vapour pressure than liquid bromine. Using a rotating device, the rate of gold dissolution was determined at various concentrations of this reagent. The reactivity of pure pyrite, arsenopyrite and chalcopyrite minerals was also evaluated in stabilized bromine reagent. Furthermore, bromine leaching of gold in a number of gold bearing ores was undertaken. Results showed that significantly higher gold recovery can be achieved with bromine than with cyanide when leaching gold encapsulated in sulphides, but bromine consumption was high owing to simultaneous oxidation of the sulphides. The greatest promise for the bromine leach process was with oxidized gold ores. The recovery of gold from oxide ores with bromine was comparable to that achievable with cyanide and bromine consumption was reasonable when leaching was conducted at a near neutral pH of ~6. In the case of oxidized gold ores containing copper mineralization, it is possible that bromine consumption may be lower than cyanide consumption, since there is evidence to suggest that bromine is less reactive than cyanide with copper minerals.

Jan 1, 2014

By B. Stimpson, K. Kosar, K. Barron

"A number of high wall failures have occurred in some of the Alberta coal strip mines of a type called by the authors ""Multiple block plane shear slope failure "". They cause rapid deterioration of the dragline bench, reduced productivity and maintenance costs.The failures are invariably associated with the presence of almost horizontal (± 5 degrees) bentonitic clay bands in the overburden, often immediately above the coal seam, and regress behind the slope as a series of tension cracks which isolate detached blocks. As many as 17 sets of cracks have been observed, at lateral distances in excess of five times the slope height from the toe.The theory of this mode of failure is presented and a limiting equilibrium computer program which will produce deterministic or probabilistic (Monte Carlo) solutions is briefly described. A case history of one such failure is documented. It is shown that the extent of the regressive failure is exceedingly sensitive to the water table elevation, leading to the conclusion that drainage, if practical, represents the best control strategy. IntroductionA number of high wall slope failures are occurring in some of the coal strip mines in Alberta of a type called by the authors ""Multiple block plane shear slope failure""(I). These failures cause a rapid deterioration of the bench from which the dragline operates, reduced productivity, and necessitate conregresses into the slope as a series of tension cracks and detached blocks. As many as 17 prominent cracks or crack zones have been observed, the last being in excess of five times the slope height distant from the toe.The block between each pair of cracks must be at limiting equilibrium, i.e. the factor of safety equals one. This condition can be used to determine the locations of the cracks which develop in sequence behind the face."

Jan 1, 1986

By R. Simkus, J. K. Gowans

Polaris Operations, a Cominco Ltd. lead-zinc mine, is located on Little Cornwallis Island, Northwest Territories, at Latitude 75°23' N and Longitude 96°75' w. When the Polaris Mine went into operation in late 1981, it became the world's most northerly base metal mine.The Polaris Concentrator, housed in a unique process barge, is a basic lead-zinc concentrator where flotation is used to produce the lead and zinc concentrates.The paper describes the ""coarse lead"" flotation feature incorporated in the concentrator flowsheet and describes the start-up problems and continuing operation of this circuit.

Jan 1, 1984

By J. B. Scott

"A computerized cost estimating program developed with the use of the Lotus 1-2-3 spreadsheet program has produced dramatic savings in preparing estimates for operating costs, equipment fleet size and manpower requirements for underground mines.The program is used by Dynatec to support its consulting engineering projects, particularly feasibility studies. The 'first principles' approach is used to prepare detailed estimates under direct labour and supplies categories and maintenance costs for each mining operation . User notes have been developed to guide the estimator and ensure appropriate consideration is given to the specifics of the particular mine.A typical case history is illustrated and the ease by which alternatives and sensitivity analyses can be prepared is demonstrated. IntroductionHistorical MethodsMining engineers have used one or a combination of methods to prepare operating cost estimates for new or existing mine s. Operating companies have access to historical cost data and generally use this for preparing estimates. Consulting engineers do not usually have direct access to such information and must rely on mining companies (the present or previous clients); publications (text books, equipment manufacturers manuals, CMJ reference manual, etc.); annual reports (applicable to public companies); previous studies (to be used with caution as conditions change from mine to mine); and first principles (the subject of this paper), for cost information:Definition of First PrinciplesA first principles approach to cost estimating considers individual primary work elements of an operation. Quantities of work items are developed from the mine plans, production rates, geographic and physical layouts etc. The knowledgeable estimator, assisted by experienced operations personnel, can assign appropriate resources (equipment, labour, supplies and services) to each work element and establish productivities. Completion of the cost estimate is then largely arithmetic."

Jan 1, 1988

By Weng Fu, James Vaughan, Stefan Lakemond

Uranium bearing copper sulphide flotation concentrates produced from iron oxide copper gold uranium (IOCG–U) ore contains radionuclides such as 238U, 230Th, 210Pb, 226Ra, 210Po, which have the potential to reduce their marketability, thus posing a challenge to the industry. Thus, a two–stage leach process has been proposed in this study. In first stage, a sulphuric acid leach process effectively dissolve most of the 238U and 230Th into solution, but other radionulclides (mainly 210Pb, 226Ra and 210Po) remain associated with copper sulphide minerals owing to their low solubilities in sulphuric acid solution. In the second leaching stage, the use of methanesulfonic acid (MSA, CH3SO3H) is investigated to selectively dissolve the 210Pb, 226Ra and 210Po from the residue of the first stage. The results indicate that 96% of 238U, 87% of 230Th, 90% of 210Pb, 86% of 226Ra and 17% of 210Po are dissolved using 3 mol/L MSA solution at 90°C for 3 hours, which represents a dramatic decrease in the radioactivity of the copper concentrate. INTRODUCTION Australia is host to one of the largest iron oxide copper–gold–uranium (IOCG–U) deposits in the world. Most of the value in these deposits is associated with copper. In mineral processing, the gangue minerals are separated from copper sulphide minerals that report to a copper flotation concentrate. However, due to the strong association of uranium with copper minerals and hematite, even clean copper concentrates can contain significant amounts of uranium (238U) and its radioactive decay elements, of which thorium (230Th), radium (226Ra), lead (210Pb), and polonium (210Po) are the long life radionuclides. These hazardous radionuclides negatively affect the marketability of the copper concentrates. Customer copper smelters in China, Japan and Europe may consider the radionuclides penalty elements or may not be able to process the feed. Therefore, there is a strong motivation to remove radionuclides from copper concentrates at the mine site before shipping to custom smelters in global market. Hydrometallurgical leaching has been widely employed to remove radionuclides from different kinds of minerals such as copper concentrates (Ragozzini & Sparrow, 1987), zircon concentrates (Aral, Sparrow, McDonald, & Norgate, 2007), and coal ash (Lei, Qi, Sun, Xu, & Wang, 2014). Leaching using sulphuric acid (H2SO4) solutions is the most widely used process for the extraction of uranium from uranium ores due to the relatively low cost and wide availability of the acid (Bhargava et al., 2015; Gilligan & Nikoloski, 2015). The leach process involves treating ground ore slurry with sulphuric acid at elevated temperatures (typically 60–90 °C) under oxidising conditions in order to convert the uranium in the minerals 2+ from the relatively insoluble tetravalent form (UO2) into water–soluble hexavalent state (UO2), which then complexes with SO42- and forms UO2(SO4)22- in solution. The uranium oxidation is generally carried out in the presence of ferric ion (Fe3+), regardless of the reagent and oxidant used. The most commonly used oxidants for uranium include sodium chlorate, pyrolusite and oxygen (Ring, 1980). These oxidants act indirectly by converting ferrous sulphate, formed by the oxidation reaction of UO2 in slurries, into ferric sulphate. The presence of Fe–containing gangue minerals such as hematite in the ore usually provides sufficient Fe required for the oxidation of UO2. After sulphuric acid leaching, the locked thorium (230Th), radium (226Ra), lead (210Pb), and polonium (210Po) elements are chemically liberated from hematite and uranium mineral grains (Ciobanu, Wade, Cook, Schmidt Mumm, & Giles, 2013). However, the extraction rate of radium (226Ra), lead (210Pb), and polonium (210Po) in sulphate solution is very low due to the limited solubilities of (Ra, Pb, Po)SO4 (Bagnall & Freeman, 1956; Liu & Papangelakis, 2006; Nikitin & Tolmachev, 1933).

Jan 1, 2019

By Ruy L. Rodrigues

Vale is in the early stages of commissioning its Onça Puma nickel operations. The project is meant for the production of 58,000 tpa of nickel contained in ferro-nickel, substantially contributing to the company?s vision to achieve world leadership in the nickel business. Mineral resources will be exploited from the homonymous deposits in the Midwest of state of Para, Brazil ? some 100 km southwestwards from the company?s Carajás iron ore properties. Resources as of 83 Mt at 1.73 % Ni will sustain a mine life of approximately 40 years. The property was acquired in late 2005 and Vale has since extended the engineering studies and proceeded with the implementation. Nickel will be mined from saprolitic ore at a rate of approximately 10 Mtpa (ore plus waste) in early years ? ramping up to some 15 Mtpa 7 years later ?, to feed the plant at a rate of 2.5 Mtpa. The process uses conventional RKEF (Rotary Kiln Electric Furnace) pyrometalurgical route whereby the ore is homogenized, calcined in rotary kilns, melted in electric furnaces and further refined to ferro-nickel. The plant has been designed and constructed applying the latest available technology, aligned with Vale?s vison to exceed the highest existing standards for environmental control, health and safety and productivity in the industry. Total investments in these operations are anticipated to correspond to USD 2.3 Bi and will materially contribute to the regional development and well being of the nearby communities and other stakeholders.

May 1, 2010

By Keith Merriam, Jim McDonnell, Peter Radziszewski, Rob Rotzinger, Ian DeHart

"Taseko Mines Limited Gibraltar copper-molybdenum mine recommenced operation in 2004 with the initiation of a series of development projects to increase throughput capacity as well as modernize the mine.In the second staged development project, a VTM-1250-WB regrind mill was selected to replace the existing conventional ball regrind mill to achieve a target grind size of 80 % passing 45 µm. In the third staged development project, a second VTM-1250 regrind mill was selected for installation in Concentrator #2, to match the existing Concentrator #1 Vertimill. This resulted in approximately 25% spare regrind capacity in the Concentrator #2 design, complete spare parts interchangeability and potential future expansion capacity to 50,000 t/d with no circuit upgrades.In this context, a study was initiated to assess not only the performance of a Vertimill grinding circuit processing a copper concentrate to a particle size of 80% passing 17 µm but also to provide Taseko’s New Prosperity project specific design information for grinding to particle sizes below 80 % passing 25 µm.The objective of the work described in this presentation was to explore Vertimill ultrafine (sub 100 µm) grinding test methodologies at both the lab and pilot scales, compare the scale-up data with operational data from the VTM1250 at Gibraltar Mines and subsequently apply this information to particle sizes down to 80% passing 17 µm. The presentation will describe the results obtained preceded by a description of the Gibraltar regrind circuit historical operation and operational performance as well as a description of the Vertimill technology.INTRODUCTIONTaseko Mines Limited is a mining company headquartered in Vancouver, British Columbia, Canada. In addition to mining development projects for copper, copper-gold, gold, and niobium properties, Taseko Mines is seventy-five percent owner and the operator of the Gibraltar Mine near Williams Lake , British Columbia. Taseko Mines Limited’s Gibraltar copper-molybdenum mine recommenced operation in 2004 with the initiation of a series of development projects to increase throughput capacity as well as modernize the mine.Metso is a leading process performance provider, with customers in the mining, oil and gas, and aggregates industries. It has corporate headquarters in Helsinki Finland, offices in 50 countries and manufacturing facilities on five continents. Amongst other types of equipment and services, Metso designs and manufactures VERTIMILL® (VTM) Grinding Mills."

Jan 1, 2015

By S. Espley, T. Nyabeze, D. Beneteau

"Many mentorship programs are available to Canadian mining industry employees. Some are company-led initiatives, whereas others are provided through educational institutions or nonprofit organizations. In 2016, a national survey was launched to gain insight into perceptions of what mentorship is, learn about available programs, and collate experiences with formal and informal mentorship opportunities. This paper outlines survey findings and delivers recommendations to industry for consideration in employee mentorship programs. In addition, mining industry leaders share their mentor/mentee perspectives. The intent of this paper is to bring awareness of best practices that can help employees grow and develop in their profession.RÉSUMÉ Les employés de l’industrie minière canadienne ont accès à de nombreux programmes d’encadrement. Certains sont des initiatives menées par les sociétés, d’autres sont proposées par le biais d’établissements d’enseignement ou d’organismes à but non lucratif. En 2016, une enquête à l’échelle nationale a été lancée en vue d’obtenir des informations quant à la perception de ce qu’est réellement l’encadrement, de découvrir les programmes proposés et de comparer les expériences aux possibilités d’encadrement, officielles ou non. Cet article présente les résultats de cette enquête et fournit des recommandations à l’intention de l’industrie afin qu’elle les prenne en compte dans ses programmes d’encadrement des employés. En outre, des chefs de file de l’industrie minière partagent leurs points de vue conseillers/protégés. L’intention de cet article est de sensibiliser les employés aux meilleures pratiques, ce qui les aidera à évoluer et à se développer dans leur profession. INTRODUCTIONThis paper about mentorship in the mining industry is based on voluntary responses to a cold survey, written and circulated by the authors. In 2016, a link to an online mentorship survey was circulated to males and females in the mining industry with the belief that mentorship programs should be available to everyone. The link was delivered via the authors’ personal networks in mining, the CIM Reporter, Women in Mining (WIM) email blasts, LinkedIn, and Facebook. This paper summarizes the answers to the survey questions. The paper is a follow up to one by the same authors (Nyabeze, Espley, & Beneteau, 2010), which was written to gain insight into why women join and stay in the mining industry, and to learn why the overall representation of women is low."

Jan 1, 2018

By Oy Leuangthong

Red Dog mine is the world's largest Zn producer. The deposit consists of sulphide ore zones in sedimentary exhalative (sedex) deposits, and is characterized by the presence of multiple metals and multiple ore types. The objective of the case study is to characterize seven different minerals, Zn, Pb, Fe, Ba, sPb, Ag and TOC, within eight different rock types. Geostatistical models were constructed for each variable within the eight rock types, and subsequently assembled to give 40 realizations for six 25ft benches. The stepwise conditional transformation was used to account for the complex multivariate relations. In addition to reproducing the input data, histogram and variogram, the resulting models also respect multivariate relations locally and globally. This paper documents the methodology to construct these models. A thorough validation procedure was implemented. Comparisons with blasthole data show that the conditional simulations and the long-term models agree in expected value. The main advantages of the conditional simulations are (1) the explicit accounting of multivariate relations between the data in model construction, and (2) the ability to quantify variability and uncertainty at any scale. A small exercise comparing the profit from a kriged and a simulated model is also examined. Results show that the simulation approach showed a 3% increase in profit, relative to the conventional estimation approach.

May 1, 2004

"Air Products approached LAC Minerals in 1987 to initiate trials with pure oxygen in the leach circuit at several LAC facilities in Canada. This paper gives an overview of oxygen use and covers specific operating data from the Doyon and Terrains Aurifères mills near Val D'Or in northwestern Quebec. LAC also uses oxygen at the Macassa mill in Kirkland Lake, Ontario.In addition to the LAC facilities, oxygen is currently in use for test purposes at the Holt McDermott mine in Kirkland Lake, Ontario and the Camflo mine near Val D'Or.There are two requirements for oxygen in the cyanide leach mill. Firstly, oxygen is required in the familiar gold dissolution reaction as follows:(1) 4 AU (s) + 8 NaCN (aq) + 02 (aq)+ 2H 20(aq) - 4NaAu(CN) 2(aq)+ 4Na OH(aq)Of the reagents on the left side of the equation, the availability of gold is fixed by the ore in question. Obviously, water is available in excess, 1eaving cyanide and oxygen as the limiting constituents in the process. Most mills operate with an excess of cyanide, which is fairly closely monitored. Dissolved oxygen levels, however, are not normally watched very closely and find their own level based on the temperature, the availability of compressed air and the ability of the ore to consume oxygen.Typical D.O. levels are in the 3-8 ppm range, however levels less than 1 ppm are not uncommon for refractory ores.With pure oxygen, dissolved oxygen levels as high as 30 ppm can be achieved. (Figure #1). This greatly accelerates the kinetics of the leach reaction and may also shift the reaction further towards completion thus increasing gold dissolution slightly."

Jan 1, 1990