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Overview of Presentation ?About MiHR ?Human Resources Challenges in the Minerals and Metals Industry ?Getting the Facts -Sector Study Project ?Key Findings ?Recommendations ?Conclusions ?MiHR?srole

May 1, 2006

By Éric Côté

Introduction The 425 Main Ore Zone ? Block of ore partially mined in the late sixties; ? Area was sealed off for over 30 years due to SO2 emissions from oxidizing fill material; 425 Project goal ? Bring the zone back into production without jeopardizing the mine; ? Minimize risks associated to SO2;

Feb 1, 2008

By A. S. H. Kabir, I-H. Jung, J. Su, S. Yue, M. Sanjari

The final mechanical properties of wrought magnesium alloys are mostly controlled by microstructure and crystallographic orientation or texture. In common magnesium alloys, grain coarsening occurs during annealing process and formation of undesirable basal texture cannot be changed markedly. The aim of this work is to investigate the effect of static precipitation on microstructure and texture evolution during annealing at 250 °C after warm rolling of Mg-Al-Sn alloy. Mg-3Al-3Sn (wt. %) alloy has been designed using thermodynamic modeling software, FactSageTM, based on forming target stable and incoherent Mg2Sn precipitate within the industrial deformation temperature range. Microstructures and precipitation were investigated by optical and scanning electron microscopes and macro-texture was measured by X-ray diffraction (XRD) techniques. It was found that static precipitates form in a large scale at the recrystallized grain boundaries and retards the grain growth during annealing. Slight weakening in basal texture was also observed during annealing.

Jan 1, 2014

By M. Kaya, A. R. Laplante

"Since the beginning of eighties the use of flotation columns has surged in Canada and abroad; the metallurgical superiority of columns over mechanical cells is in great part due to froth washing, which ensures higher gangue rejection and selectivity. Can wash water, which has proven so beneficial, be used in mechanical cells? Although froth washing technology was widely implemented in Soviet plants for bi tuminuous coal, and alusite, powellite, scheelite, molybdenite, etc. more than 25 years, it has been neglected in the western world. Published data suggest 10 to 15~ increases in grade and/or recovery with wash water in mechanical cells (Klassen and Mokrousov, 1963). There are at least three wash water plant applications in Zaire, Chile, and Canada, but little, if any, published information is available. This research work, which is the first extensive fundamental study related to froth washing in mechanical cells, attempts to answer the questions of how, how much, and where should wash water be added.This project was undertaken in three stages:1. Bench-scale laboratory tests with a 6.5 L Denver cell at McGill using a silica flour and a slime reject from Niobec (St.Honor6).2. Pilot-plant scale tests with a 65 L Denver cell at McGill using the silica flour and a complex Cu-Ni sulphide ore from the Strathcona mill of Falconbridge.3. Plant-scale tests with a bank of 2800 L Denver cells at Falconbridge Ltd. for complex Cu-Ni sulphide ore and Eastmaque Gold Mines Ltd. for Au tailing reclaimation."

Jan 1, 1989

By Nadarajah Nanthananthan

Mine backfill has been widely used as a means of ground support. While proper design of backfill is important to ensure ground stability, understanding the failure mechanism and the various influencing factors in a filled block is essential. This paper presents a modified sliding failure model of a confined backfill block. The model considers both the gravity load of the backfill itself and the overlying load from fragmented ore or backfill on the top. A series of new equations were derived and the relationships between factors such as factor of safety, friction angle, cohesion and the exposed stope height were developed. This modified model will be a very useful tool in backfill design, for example, to optimize the design of backfill for a given stope geometry or to determine the maximum backfill height for a particular type of backfill.

May 1, 2007

By Navid Bahrani

Introduction ? Today?s economic market is motivating underground mining companies to increase development advance rates and enhance their NPVs. ? For example, block cave mining involves development of kilometers of drifts with multiple pillars. ? The cyclic nature of drill and blast, and its inherent tendency to damage the surrounding excavation rock mass and increase support demand often result in poor advance rates ? This has motivated mining companies to replace the conventional drill-and-blast as the main excavation method with alternative methods such as mechanized excavation. ? There is little experience with mechanized or non-explosive excavation methods in hard rock metalliferous underground mining.

Oct 1, 2010

By Zia Pirzada

"Time is of the essence" and "Time is money" These are powerful and true statements during a project life cycle and have far-reaching implications on the success and failure of the project Time and progress management is crucial to the project success. Project delays may increase the cost to an unacceptable level and may render the project as economically unfeasible. On the other hand, if the project is completed on time or earlier than as planned, it may generate economic benefits greater than what had been envisioned To take advantage of the financial opportunities and to improve the cash flow as well as Return On Investment (POI), project schedule can be accelerated to complete the project earlier than planned Project schedule acceleration can be achieved by using analytical tools, such as "Schedule Optimization", "Schedule Reduction", "Schedule Compression" or a combination of any of these concepts along with the "Planning for start up". Schedule optimization does not entail any extra cost, however, other acceleration methods, such as Schedule Reduction and Schedule Compression, may require extra expenditures from the owner. Based on the forecasted early start of the revenue stream, the extra expenditure could become a worthwhile venture with a very high rate of return To accelerate the schedule, all aspects of the project should be reviewed with acceleration costs calculated. All risks and opportunities should be evaluated and taken into consideration to determine if the acceleration is feasible and advisable and will provide definite financial advantages Sometimes schedule acceleration may be desired to prevent the company from paying liquidated damages. This is especially true when the project is not expected to complete on the contractual completion date and when the cost of acceleration is less than the liquidated damages that may accrue against the company.

Oct 1, 2010

By P. Keller, T. E. Lister, G. G. Clark, L. A. Diaz

As electronic technology continues to evolve there is a growing need to develop processes which recover valuable material from antiquated technology. This need follows from the environmental challenges associated with the recovery of raw materials and fast growing generation of electronic waste. Although present in small quantities in electronic devices, the availability of raw materials such as rare earths and precious metals becomes critical for the production of high tech electronic devices and the development of green technologies (i.e. wind turbines, electric motors, and solar panels). Therefore, the proper recycling and processing of electronic waste presents an opportunity to stabilize the market of critical materials, providing a proper disposal and treatment of a hazardous waste stream. This paper describes the development and techno-economic assessment of a comprehensive process for the recovery of value and critical materials from electronic waste. This hydrometallurgical scheme aims to selectively recover several value streams (base metals, precious metals, and rare earths) present in electronic waste. The economic feasibility for the recovery of rare earths from electronic waste is mostly driven by the efficient recovery of precious metals, such as Au and Pd (ca. 80 % of the total recoverable value). Rare earth elements contained in magnets (speakers, vibrators, and hard disk storage) can be recovered as a mixture of rare earth oxides which can later be reduced to the production of new magnets.

Jan 1, 2016

By C. B. Mapes, E. C. Dowling Jr.

"To reduce concentrate dewatering and drying costs, the Concentrator Division at Phelps Dodge Morenci, Inc. investigated available filtration technologies. Numerous methods were explored, including: drum, disk, belt, pressure, hyperbaric, and ceramic media filtration. An economic evaluation of the individual filtration technologies indicated the advantages of ceramic media filtration for Morenci concentrates. This paper discusses the technological development culminating in the first full scale application of ceramic media disk filters in North America. Low moisture contents are obtained at high production rates and greatly reduced operating costs.INTRODUCTIONPhelps Dodge commissioned the Morenci Concentrator Filter Plant in 1942 with four 8'6"" Dorr-Oliver cloth disk filters. That year, the filter plant processed 265,537 tons of concentrate grading 20.5% Cu. The filter cake production averaged 9.3% moisture. In 1944, the Extension Filter Plant commenced operation with three additional 8'6"" Dorr-Oliver cloth disk filters. This coincided with the expansion of the concentrator. Production that year totaled 451,567 tons of concentrate grading 23.8% Cu. Moisture averaged 9.4%.Through the years additional filter units have been added in response to increased concentrate production. An Eimco drum filter was installed on the extension side and an additional Dorr-Oliver disk filter was installed on the original side in the 1950's. In 1961, two 8'6"" Peterson disk filters were installed, one on each side to replace two worn-out DorrOlivers. The installation of four 10xl2 foot Peterson drum filters was completed in 1974, coinciding with the Metcalf Concentrator startup. An Eimco belt filter was installed later.The greatest change to concentrate dewatering at Morenci occurred in 1963 with the addition of a 10x60 foot rotary gas fired dryer. The installation also included a number of conveyors to deliver filter cake from both plants to and from the dryers. Other ancillary systems included dust scrubbers and their slurry pumps. The commencement of drying was undertaken due to the rapid increase in cake moisture as a result of the LPF process and the recycling of acid plant scrubber dust slurry from the smelter. In 1972, a second dryer system was installed to increase capacity."

Jan 1, 1993

By Arash Habibi

The FMC Westvaco Trona Mine is located near Green River, Wyoming and has an annual production of 4.5 M tons. The underground mine has three active development panels and one longwall panel. The mining horizon is about 500 m below surface and strata liberate methane. Three surface-based blowing fans provide ventilation air. A ventilation survey and subsequent analysis was undertaken and a simulation model developed. Air heating during winter is essential to prevent freezing of pipelines and to lesser degree, for miner comfort. Air at all three intake shafts is heated using gas-fired heat exchangers. A strata heat study was conducted in one of the active panels to determine rock attributes. Tests included in-situ measurements of rock thermal conductivity and geothermal gradient. Continuously methane monitors have also been installed in an active development panel?s return drift. Ventsim ventilation software was used to aid the heat and contaminant simulation study. An exercise was also undertaken to gain some understanding of methane contaminant levels throughout the mine. It was further used to determine an adequate surface intake air heating rate and consequently the minimum natural gas consumption needed for winter intake air heating at the mine.

Aug 1, 2013

By J. F. Perreault, J. Paraszczak

"The profitability of an underground mine depends to a great extent on the production cost.Random equipment failures and their consequences have significant influence on the total operating cost of a mining system. Having this in mind, a reliability study has been initiated for loadhaul- dump machines in an underground mine. The main purpose of this study is to identify the critical machine subsystems, determine their failure pattern and help work out an effective maintenance strategy. In the first part of this study, the failure data of diesel powered LHDs, gathered during an I8-month period have been analyzed. For the purpose of the analysis, the machines have been treated as systems comprising seven subsystems connected in series. The most critical subsystems, i.e. electrical and hydraulic, were further investigated, and analyzed by graphical and analytical methods. Different failure distribution models were applied and discussed. Basic Defmitions and ConceptsIn order to avoid confusion, several terms used in this paper are defined below, as compiled by O'Connor (1991). The acronymsBS and MIL-STD stand respectively for: British Standard and US Military Standard.Failure: the termination of the ability of an item to perform a required function (after BS 4778).Time Between Failures (TBF): the length of time between two consecutive failures.Observed Mean Time Between Failures (MTBF): For a stated period in the life of an item, the mean value of the length of time between consecutive failures computed as a ratio of the cumulative observed time to the number of failures under stated conditions (after BS 4778).Maintenance, Corrective: The actions performed, as a result of failure, to restore an item to a specified condition (after MIL-STD-721 B).Maintenance, Preventive: The actions performed in attempt to retain an item in a specified condition by providing systematic inspection, detection and prevention of incipient failure (after MIL-STD-721B)."

Jan 1, 1994

By M. Hall

"SomarioEl circuito de molienda a Selbaie consta de molino semiaut6geno en un circuito cerrado y molino de balas en un circuito cerrado. El amperaje del motor de se usa controlar el tonelaje el molino. Este sistema estabiliza el circuito pero no mejora activamente el rendirniento del circuito. Se desarroll6 auxiliar el rendimiento del circuito un sistema experto en manipular las objetivos de existir control proporcional-integral. Se ejecut6 el sistema con el Comdale /C conjunto del sistema experto y ha side funcional hace tiempo el mayo de 1992. El sistema experto ha resultado en un aumento en tonelaje de 7tph y una disminuci6n de $210,000 en el caste anual de media de molienda. Se describe el desarrollo del sistema y los provechos derivar se presenta.AbstractThe grinding circuit at Selbaie consists of SAG mill and ball mill closed circuit grinding. The SAG mill motor current is used to control throughput. This system stabilizes the circuit but does not actively optimize circuit performance. An expert system was developed to aid the optimization of the circuit by manipulating the set-points of existing PI control loops. The system was implemented with the Comdale /C expert system package and has been on line since May 1992. The expert system has resulted in a net increase in tonnage of 7tph and a decrease in annual grinding media costs of $210,000. The system development is described and the benefits derived are presented."

Jan 1, 1994

By Don Lemmen

Impacts, Adaptation and Vulnerability ? regional climate changes (temperature and extreme events) have already affected many physical and biological systems ? natural systems are vulnerable to climate change, some will be irreversibly damaged ? many human systems are sensitive to climate change ? Projected changes in climate extremes could have major consequences

Nov 1, 2002

By Q. Ricoux, F. Goettmann, A. Maihatchi

"Electrodeposition processes are widely used in the metallurgical industry to produce, extract and refine metals from various feed materials. However, raw materials used to provide non-ferrous metals often contain high amounts of iron. In the presence of iron, while metals are plated at the cathode, electrowinning processes produce corrosive and highly oxidative ferric ions at the anode that are harmful for the process sustainability. In fact, these ferric ions cause dramatic current efficiency loss, induce high maintenance expenditures to limit the corrosion of devices and it results in the formation of impure and dendritic deposits on the cathode. Consequently, the management of iron in electrodeposition process became a major issue in non-ferrous metals production. Actually, numerous methods have been developed to limit the ferric ion concentration in the electrolyte or, at least, to limit its harmful effect. Many methods aim to limit the iron(III) concentration in the electrolyte, generally by coupling electrowinning to extraction process such as solvent extraction (SX) (Bender & Emmerich, 2015), ion exchange (IX) (Gula, Dreisinger, & Horwitz, 1996) or cementation (Kust, 1979) processes to remove ferric ions. Other routes consist of (i) using the ferric ions oxidant properties to leach raw materials, either directly in the electrolytic cell (Fanta & Tributsch, 1975) or through a secondary circuit (Cain, 1950), or (ii) reducing ferric ions through periodic reversal of direct current to enhance the formation of Fe2+ (Loutfy & Bharucha, 1980). On the other side of the spectrum, papers discuss methods to valorize the iron from by-products of the non-ferrous metal industry, that generates vast quantities of iron containing wastes (A. Agrawal, Sahu, & Pandey, 2004). Many studies on iron electroplating and electrolytic iron production from ores have been carried out (Cain, 1950; Mostad, Rolseth, & Thonstad, 2008), but very few have been conducted on waste or by-products. Therefore, we propose to build on the previous literature review to develop a process for the production of electrolytic iron from by-products.INTRODUCTIONNon-ferrous metals and their alloys are used in a large variety of applications. Aluminum and titanium are used for their strength, light weight and corrosion resistant properties in structural applications. Copper has been used in various applications requiring high thermal and electrical conductivity, as kitchen products and electrical wires. Nickel and zinc are commonly used as plating materials; nickel offers a wide range of working temperature and zinc is used for steel plating. Gold, silver, and platinum group metals are used in electrical/electronic applications, jewelry and chemistry as catalysts."

Jan 1, 2016

By Robert B. Parsons

"This article is based on a paper presented by Jim Scott at the 1988 annual convention of the Prospectors and Developers Association of Canada. The paper suggests a number of factors that might be taken into account in negotiating royalty terms.IntroductionRoyal ties are a part of mining life in Canada. They are used by many kinds of individuals in many kind s of situations. Prospectors commonly take royalty interests back when they transfer claims to development companies. Mining companies disposing of undeveloped (or sometimes even developed) properties are often paid at least in part by royalties. Royalties are even used by institutional investors with no other connection with the resource industry.Such different royalty holders have different investment goals, different cash flow requirements, and different risk / return preferences. These differences have given rise to a number of different royalty type s. These types range from the simplest cents-per-ton royalty (where the operator pays a royalty at a fixed rate per ton milled) to net smelter return or ""NSR"" royalties (where the royalty is based on a percentage of the operator's NSR) all the way to net profit interest or ""NPI"" royalties (where the royalty is based on the operator's bottom-line net profit),The fundamental difference between the many royalty types is in the risk/ return relationship. The cents-per-ton royalty, for example, is relatively risk-free. Of the many economic factors which affect a mine, the only one which will affect the royalty holder is the amount of ore physically milled. On the other hand, the potential for significant gains under a cents-per-ton royalty is also very limited. The royalty holder will not share in any increases in the market price of the end product or any cost reductions achieved by the producer."

Jan 1, 1988

By Robert B. Parsons

"This article is based on a paper presented by Jim Scott at the 1988 annual convention of the Prospectors and Developers Association of Canada. The paper suggests a number of factors that might be taken into account in negotiating royalty terms.IntroductionRoyal ties are a part of mining life in Canada. They are used by many kinds of individuals in many kind s of situations. Prospectors commonly take royalty interests back when they transfer claims to development companies. Mining companies disposing of undeveloped (or sometimes even developed) properties are often paid at least in part by royalties. Royalties are even used by institutional investors with no other connection with the resource industry.Such different royalty holders have different investment goals, different cash flow requirements, and different risk / return preferences. These differences have given rise to a number of different royalty types. These types range from the simplest cents-per-ton royalty (where the operator pays a royalty at a fixed rate per ton milled) to net smelter return or ""NSR"" royalties (where the royalty is based on a percentage of the operator's NSR) all the way to net profit interest or ""NPI"" royalties (where the royalty is based on the operator's bottom-line net profit),The fundamental difference between the many royalty types is in the risk / return relationship. The cents-per-ton royalty, for example, is relatively risk-free. Of the many economic factors which affect a mine, the only one which will affect the royalty holder is the amount of ore physically milled. On the other hand, the potential for significant gains under a cents-per-ton royalty is also very limited. The royalty holder will not share in any increases in the market price of the end product or any cost reductions achieved by the producer."

Jan 1, 1989

By J. Karonen, M. Tiihonen, J. Guentner, L. Haavanlammi, Outotec GmbH, E. Kolehmainen

"Rare earth elements have obtained significant attention during the last few years due to predicted increase in their demand. Several projects worldwide are at pre-feasibility or feasibility stage aiming to commence production. Deposits of rare earth elements are typically complex and multi-metallic of nature. This means that production processes are often also complex and therefore, various metallurgical unit processes are needed. Outotec’s equipment and technology portfolio is very comprehensive and includes hydrometallurgical and pyrometallurgical apparatus and processes applicable to the efficient exploitation of rare earth deposits. Outotec has gained useful experience relevant to the processing of rare earths through several assignments including those for Alkane Resources Ltd. (Dubbo Zirconia Project), Greenland Minerals and Energy Ltd (Kvanefjeld Project), Frontier Rare Earths Limited (Zandkopsdrift project), Tantalus Rare Earths AG (Madagascar), Quest Rare Metals (Strange Lake project) and Orbite Aluminae Inc. (HPA project). The hydrometallurgical test work of two process flowsheets is presented in the paper. A roasting or acid baking step is common to several proposed rare earth projects. In the past, rotary kilns have been used, but Outotec has developed a new process concept to handle the rare earth material in fluid bed reactors. The basis for this development is long experience in fluid bed technology of Outotec in Germany. One advantage of fluid bed roasting is the higher throughput per unit. In combination with the roasting and baking, Outotec offers the gas cleaning and acid plant and provides a complete and closed concept.INTRODUCTIONRecovery of rare earth elements (REE) has obtained significant attention during recent years. It has been estimated that their demand will be boosted because of their need in many technology areas. REE can be utilized in magnets, batteries, displays, catalysts, optical devices etc. (Jordens, Cheng, & Waters, 2013; Zhang & Edwards, 2013). The production of REE is focused in China, which means that production outside of China is very scarce. However, there are multiple active development projects worldwide working towards production of REE containing products outside of China (Chen, 2011)."

Jan 1, 2016

By D. R. Hatton

To obtain sufficient material on which to perform copper-molybdenum separation testwork a variability set of drill hole reject samples amounting to several tons was put together to include the different ore types proportions expected in the copper circuit. The samples were treated in a copper circuit pilot plant and enough mass of bulk concentrate was recovered to conduct copper moly separation tests in the laboratory. Tests consisted of stage flotation reactor (SFR) rougher pilot plant tests, conventional laboratory rougher, cleaner and 4 stage open circuit cleaner tests. The mineralogical liberation analysis of the feed and concentrate was used to model the effect of liberation on the grade-recovery relationship of the different samples. Mineral kinetic parameters for the various samples were determined by calibration to the test data. The copper concentrate results as simulated from previous studies on the same deposit were used to simulate the variability in head grade and throughput expected for the feed to the copper molybdenum separation circuit for each of the first 10 years of production. This variation in feed was then simulated through the separation circuit to obtain optimised molybdenum grade recovery curves to forecast the circuit production for each of the first 10 years. INTRODUCTION Incorporating Geometallurgy into the design for a copper molybdenum separation is especially challenging due to the low mass of final concentrate typically produced during testwork. This is due to the low molybdenum head grades and high overall molybdenum upgrading expected. With molybdenum head grades of around 300 ppm, 1 tonne of copper circuit feed is expected to produce around 300 g of molybdenum concentrate in the plant. In the laboratory however, this may end up only resulting in a few grams. Obtaining sufficient mass for laboratory testing therefore requires starting with a large initial sample and careful testwork planning to maximise the utilisation of this mass. A testwork program was designed to investigate the effect of ore variability on the copper molybdenum separation circuit (here after referred to as the molybdenum circuit). Composite samples were selected to represent the various ore types, copper content, moly content, pyrite content and clay contents expected in the copper circuit feed. These samples were run through a bulk copper pilot plant to create the feed for the molybdenum testwork. The molybdenum testwork consisted of rougher kinetic flotation tests, rougher cleaner kinetic tests, rougher cleaner kinetic tests with regrind, stage flotation reactor (SFR) pilot plant tests, open circuit cleaner tests. These tests were used to calibrate the ore kinetics in the IGS-FLEET model for simulation of the molybdenum circuit performance.

Jan 1, 2019

Applications of proven real time, through-conveyor elemental analysis technology and benefits achieved will be discussed using case studies in base metals, iron ore and phosphate operations. PGNAA (Prompt Gamma Neutron Activation Analysis) technology and its background in minerals applications and applications which are expected to further improve its utilization will be reviewed. Short payback through operational benefits such as removal of waste from feed, increased feed grade and overall improved productivity will be demonstrated based on results achieved at several processing operations. PGNAA technology is most applicable to conveyed flows as it is unaffected by belt speed, particle size, segregation/layering, mineralogy or dust. As a transmission method able to penetrate in excess of 500mm of rock it provides extremely representative results continuously measuring through the full conveyed cross section and reporting results typically on one to five minute accumulated increments to the control room. Multi-elemental results and moisture content are used for active process control: diverting conveyed flow increments(bulk sorting), blending ore types in plant feed, and providing advance warning of significant quality changes to the downstream plant operators (e.g. flotation). Elements of interest may include deleterious components as well as target metals. Ore feed quality measurements are also useful in metal accounting, ore reconciliation and real time feedback to mining operations. Further benefits can result when combined with other technologies such as particle sorters, to upgrade diverted increments of subeconomic material to achieve higher feed grades and lower deleterious content to the main process. Measurement of elements (e.g. silica) which correlate with ore hardness or grinding characteristics can be used to moderate feed rate to grinding mills to prevent overload, hence optimizing grinding performance and reducing energy and grinding media consumption. Pebble flows can be analysed and uneconomic increments diverted to prevent recirculating flows consuming mill capacity unnecessarily. This also increases average feed grade.

Jan 1, 2016

By Yoginder P. Chugh

Beginning in 2010, a scientifically-founded water spray system for continuous miners (CMs) has been in development at Southern Illinois University that significantly reduces respirable dust exposure for workers in the face area (patent pending). It includes engineered sprays around the cutting drum, outer bitring sprays, chassis sprays and side cutter boom sprays. About 3.6?4.5 m behind these sprays are additional sprays that cover the area between the CM chassis and the mine roof and ribs. The innovative spray system uses approximately the same volume of water as spray systems currently used on CMs and with similar operating pressures. The innovative spray system design also takes into consideration coal dust wettability. An Illinois mine decided to implement these concepts on a CM during the rebuild stage. Dust control performance of the rebuilt CM was evaluated using gravimetric dust sampling and real-time monitoring with multiple personal dust monitors. The average results based on gravimetric sampling of about 105 cuts show about 30 and 20% reduction in dust exposure for the miner operator and the haulage unit operator, respectively. Visibility in the mining areas was also significantly improved. Since the initial demonstration, the coal company has implemented the system on all of their operating CMs.

Aug 1, 2013