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By M. Board, R. Pakalnis, S. Seldon, R. Brummer

The Kidd operation mines roughly 10 000 tpd of copper and zinc ore from underground and employs about 700 personnel. In the late summer and fall of 1997, major movements in the proximity of the east wall of the Kidd open pit had been observed. The Kidd pit had been mined from 1965 to 1977 to depths of 260 m (850 ft), followed by subsequent mining by underground methods to current depths in excess of 1830 m (6800 ft). The No. 1 Mine (2600 Level to pit bottom) is approximately 90% extracted, with most of the remaining reserve between 2000 and 2500 levels. Although initial concerns centred on the stability of the pit walls, the potential ramifications of the movements to the underground were recognized and measures were implemented to ensure the safety of personnel as well as to minimize the potential damage to existing operations. In late October, damage to underground operations was observed as deep as the 2000 Level. In the final assessment, the global mobilized mass was a “wedge”-shaped hangingwall block extending from surface to about 610 m (2000 ft) below surface. The “wedge” boundaries are defined by a fault and shear zone which have continuous lengths in excess of 1070 m (3500 ft); its base by shearing through the host rock mass; and its eastern face by deep tension cracks (Fig. 1). Mined and filled excavations at the western face of the “wedge” allowed mobilization of a mass in excess of 30 M tonnes. Movements in excess of 75 cm (30 in.) per day were recorded on the surface stations that preceded the complete shutdown of operations on October 29, 1997. The evaluations in the days following the shut-down were centred on mitigation of immediate and future possible negative impacts on infrastructure and mining of the remaining No. 1 Mine reserves while ensuring the safety of the operators. This effort required the rapid assessment of the potential damage of the block movement on underground infrastructure, stope access, drainage and ventilation, as well as airblast potential due to the falling of a large block into the pit near the ventilation intake at the base of the pit. These assessments were presented in a previous paper (Seldon et al., 1999). In total, the lateral movement of the block on the ground surface was over 4.3 m (14 ft). This paper describes the detailed studies performed to understand the failure mechanism and to assess the impacts on future mining in No. 1 Mine.

Jan 1, 2000

By Marc C. Bétournay

Hydrogen fuelcells are a known technology, having been applied to stationary (e.g equipment, buildings, power plants) and vehicle applications (e.g transit buses, space shuttles). There is currently a growing need to provide alternate power systems to diesel fuel for underground mining vehicles to improve underground air quality and reduce production costs and green house gas emissions. To date, however, fuelcells have not been exposed to underground mine air and physical conditions. A testing program was carried out to provide information on the vulnerabilities of fuelcells as part of a number of proof-of-concept projects to apply hydrogen power to underground mining vehicles. The fuelcell type of choice for the industry, the Proton Exchange Membrane, would function at the range of temperatures encountered in underground and surface operations, and use hydrogen that is stored under low pressure and risk. A small fuelcell stack was tested in a cooperative project between CANMET, the Fuelcell Propulsion Institute, INCO, the Ontario Ministry of Labour, Sandia National laboratories and H-Power. This article will review the tests carried out to measure the effects from high humidity, mineral dust, diesel emission gasses and diesel particulate matter as well as from shock and vibration provided to the unit in underground conditions, at INCO?s 175 Orebody minesite and INCO?s Stobie Mine. The test results provided will show that the unit was not affected by the underground conditions: physically and electrically the unit performed without any reduction in operation or adverse effects imposed.

May 1, 2003

By Lori Kormos, Jhonny Carrión De la Cruz, Dominic Fragomeni, Elizabeth Whiteman, Jorge Oliveira

"Process diagnosis, flowsheet design and optimisation are most effectively and efficiently achieved through the use of metallurgical testwork combined with more modern quantitative mineralogical techniques. Integration of the mineralogical data in testwork programs provides a resolution that cannot be obtained from assays alone and can direct the flow of work to result in optimized conditions more quickly than would otherwise be possible. At Xstrata Process Support (XPS), QEMSCAN (Quantitative Evaluation of Materials by Scanning Electron Microscope) and EPMA (Electron Probe Micro Analyser) information can be employed to diagnose specific issues in a plant or lab scale test and are routinely combined with other metallurgical data sets to benchmark performance, design and optimise flowsheets. Representative sampling protocols for ore bodies or test products, the use of geometallurgical unit classification and high confidence metallurgical test programs are key components of the strategy. Two case studies from Xstrata Zinc’s Antamina Mine and Concentrator in Perú, and Xstrata Nickel’s Nickel Rim South Mine in Sudbury are described to show how the use of quantitative mineralogy were used to diagnose a plant issue and how the data can be integrated into metallurgical programs to assist mineral processing engineers to design and optimise flowsheets.INTRODUCTIONOver the past decade, there has been a shift away from metallurgical testing that employs only chemical assays to quantify performance; the use of empirical observation in order to optimise a flowsheet; and the extraction of bulk samples for testing or piloting. The integration of geological information into the planning and execution of testwork programs including the use of quantitative mineralogy has improved the overall quality and predictability of metallurgical programs. At the same time, improvements to metallurgical testwork protocols such as rigorous statistical assessment of results, the use of factorially designed experimental strategies (DOE), and replicate flotation with appropriate quality controls, has improved the confidence level in these results.Process diagnosis, which utilizes quantitative mineralogy, can clearly define the root cause of the metallurgical issue. Whether used on its own to diagnose an issue or in combination with other metallurgical testwork, the use of mineralogical data has become the standard in the mining industry."

Jan 1, 2010

By Mika Muinonen

"Dewatering of nickel concentrate at the INCO Thompson integrated mine-metallurgical site takes place within the smelter plant. The eight original 60 foot diameter cable torque thickeners of which four were operational and eight Dorrco internal drum filters have been replaced with a single Outokumpu high rate thickener and a single Lasta pressure filter. The modernization has resulted in a filter cake which has a more stable and lower moisture content. Control of the entire dewatering process has been improved and costs have been reduced.Typical filter cake produced from the Dorrco filters during processing of high tonnages of Birchtree mine ore was ~20% moisture vs. ~13% moisture for concentrate produced from the Thompson mine ore. The high moistures were correlated with the amount of fine magnesium silicate gangue in the concentrate. As Birchtree ore processing rates have increased, this filter cake moisture became unacceptable because of material handling problems and the impact on furnace metallurgy. The Dorrco filters were replaced with the Lasta filter in 2003 that has consistently produced filter cake at ~11% moisture.This paper summarizes the piloting, design, installation and commissioning of the modernized dewatering circuit.INTRODUCTIONThe Thompson integrated nickel processing facility was built in 1958 and originally consisted of a mine-mill-smelter and, soon after, a refinery.Nickel concentrate is pumped from the mill as a dilute slurry directly to the smelter facility ~200 meters along an unheated pipe trestle. Originally, nickel concentrate was de-watered using up to 8 conventional 60-foot diameter thickeners and 8 internal vacuum drum filters."

Jan 1, 2006

By Pierre Lacombe

"The operation of the Louvicourt Mine will have to rely on stringent grade control and on the optimization of the amount of blocked ore made available per given development effort. All of the above being necessary to obtain the highest throughput at the lowest mining cost.To assist in achieving these objectives, the need for production of a competent fill with short curing time was recognized early by the project partners. As well, operating costs associated with the selected method should be as low as possible while meeting the technical criteria.A feasibility study comparing filling methods showed potential benefits in all aspects of the paste fill use, except for its higher capital costs and increased operational complexity. This last consideration was tackled by the conservative design approach adopted in the flowsheet development of the paste fill plant.Since commissioning of the plant has just been completed at this time, the paper will focus on the feasibility study and its background, the design of the plant and testwork results at pilot plant and plant scale.RésuméLe succès de l 'opération de Louvicourt Mine dépendra d' un contrôle serré des teneurs du minerai et de la maximisation de la quantité de minerai développée par effort uni ta ire. Ces critères devant etre respectés afin d'obtenir le taux de production le plus élevé au coût le plus bas.De façon à satisfaire ces contraintes, les partenaires du projet ont reconnu tôt la nécessité de produire un remblai de qualité tout en maintenant un temps de curage court. De plus, les coût d'opération associés a cette opération se devaient d'être des plus avantageux sans sacrifier l'atteinte des objectifs techniques.Une étude de faisabilité comparant différentes méthodes de remblayage a démontré que le remblai en pâte offre des aspects positifs sous taus les angles, si ce n'est de son coût en capital initial élevé et de sa complexité relative d'opération. Ce dernier point fut considéré de près par l'adoption d' une approche conservatrice lors de la conception de l'usine de rernblai.Puisque la mise en service de l'usine n'a été faite que les détails de l 'étude de faisabilité et ses fondements, 1 'usine et des résultats d' essais obtenus a l'échelle de l'usine seront discutés."

Jan 1, 1995

By Frederik H. Kriel, John Ralston, Craig Priest

"Stream-based microfluidic solvent extraction offers a novel alternative to bulk-scale mixer-settler operations. However present maximum throughputs are restrictive and there are engineering challenges that need to be overcome before the technology is robust. This is especially the case for mineral processing, where circuits must be able to handle variable feed streams with long retention times and where maintenance should be minimized. This paper highlights research directed at investigating and evaluating these challenges for actual mineral leach solutions of metal ions. Molecular and particulate channel fouling is discussed. Most extraction systems studied to date show no effects that would preclude use of the technology. For rare earth elements (REE) with fast extraction rates, scale-up of volumetric throughput to 100 L/h using suitable arrays of channels, microfluidic chips and modules is shown to be achievable using a small contactor (approx. 2 m3) platform. This requires only 2–3 % of the typical aqueous phase inventory and residence time used in an equivalent mixer-settler. For a circuit with 100 contactors, the overall residence time would be less than 1 h, using an aqueous inventory of 40 L.INTRODUCTIONHydrometallurgy is of pivotal importance in many mineral processing circuits around the world, with liquid-liquid solvent extraction (SX) a key step in the separation of many base metals (e.g. Cu and Ni), radioisotopes, precious metals, and the ‘technology’ metals, such as rare earth elements (REEs) (Ritcey & Ashbrook, 1979). The standard equipment for SX in mineral processing is the mixer-settler, in which liquid dispersions are created, by agitation, to increase the surface-to-bulk ratio and, thus increase the mass transfer rate between the liquid phases. In stream-based microfluidic SX (microSX), these high surface-to-volume ratios are achieved by contacting microscopic streams (Ciceri, Perera, & Stevens, 2014), rather than forming small droplets, so that phase disengagement can be accelerated (essentially instantaneous via branching of the two streams of liquid at a channel junction). MicroSX is profoundly different from bulk mixer-settler SX operations and offers exciting opportunities for processing hydrometallurgy solutions (Kriel, Holzner, Grant, Ash, Woollam, Ralston, & Priest, 2015; Priest, Zhou, Klink, Sedev, & Ralston, 2012). Nonetheless, the advantages of using microfluidic environments are presently balanced by very significant challenges relating to throughput, process control, coupling of stages, flow stability, and fouling. If these challenges can be met using smart chip designs, process control and clever engineering, high-value/low-volume SX processes stand to benefit greatly."

Jan 1, 2016

By J. Hu, F. Lin, R. Chen, F Peng, S. Yang, W. Yu

"Microseismic monitoring technology has become one of the most effective method of mine ground pressure monitoring after decades of development. But safety assessment of mine ground pressure by using microseismic monitoring is still in the development stage, it needs to be perfected continuously in practice, and choose the optimal assessment indexes and methods. The definitions and physical meanings of wave velocity, b value, and EI-VA value are introduced in this paper. Statistical calculation of the microseismic events in Luomu Mine is finished by using these indexes, then the functions and calculation results of V, b value, and EI-VA value with the variable of time are also given in the paper. The preliminary safety assessment method is established in Luomu Mine, and it has achieved good results in practical application.1.1 Engineering background The Luomu Mine is a super large molybdenum and tungsten production base in China, ore reserves is up to 2 billion tons, first in Asia and third in the world. It begins mining since the 1960. and bases on underground mining until 2002. In order to recover resources more effectively, it began to use opencast mining method and formed a production of 30000t/d in the early 1990. After about 30 years of underground mining, a large mined out spaces was formed under open pit mine, up to area of 1.2 million m2 and volume of 18 million m3, as shown in figure 1. The large number of mined out spaces seriously affects the normal production, mining and handling of mined out spaces are in the high risk. In the past years, several rock mass collapsions happened, and it caused a serious security threat to persons and equipments. According to the distribution characteristics of mined out spaces, Luomu Mine is divided into A, B, C, D and E mining area. The stability of D mining area is studied in this article. D mining area mainly includes 1376,1350,1340,1317 mined out spaces and 1280 deep large mined out area, as shown in figure 2. The mined out spaces of D mining area is extremely complex and high-risk. Therefore, a microseismic monitoring system was built to monitor the stability of D mining area, a large number of valuable datum has been obtained, and it has a striking effect (Cheng & Peng, 2013; Peng et al., 2013)."

Jan 1, 2015

By D. F. Cooper, J. G. Paterson, K. H. Pang

"Effective control of metallurgy by manual adjustment of cell levels is common flotation practice. With an on-stream XRF analyzer interfaced to a process control computer it is possible to program the computer to carry out this function automatically. This paper describes the development and implementation of closed loop control of the concentrate and tailing grades at the Clarabelle Mill of the International Nickel Company of Canada, Limited, The XRF analyzer was used as the sensor, cell level as the control and the computer as the controller.IntroductionThe International Nickel Company of Canada, Limited recently brought on-stream Clarabelle Mill having a rated capacity of 35,000 tons per day. The plant was required to increase milling capacity in the Sudbury area by 9,000 tons per day and to improve milling efficiencies by replacing the obsolete crushing and grinding equipment at the Copper Cliff Mill. This represents the fourth mill built since 1959 and incorporates the latest thinking in a continuing evolution of instrumentation and control concepts. Table 1 illustrates control progress at Inco since 1959.In 1967 Frood-Stobie Mill came on-stream incorporating a central control room, an on-stream analyzer, a data gathering computer, and a significant change in instrumentation from direct-contacted pneumatic to miniature electronic. The computer successfully controls the analyzer but has very limited process control capability. Based on this experience a process control computer system was installed at Clarabelle Mill with the objective of carrying out extensive supervisory control and a limited amount of direct digital control."

Jan 1, 1973

By Fabio Mielli

In these times of increasing costs and diminished returns, energy consumption is one source of savings that remains relatively untapped in the mining sector. Typically, 15% to 40% of operational costs can be attributed to energy in mining operations. This ?process variable? is a complex, multi-faceted variable that involves government regulations, societal pressures, cost and competitiveness. A mining company able to successfully embrace an energy efficiency program is more often than not a successful mining company. Production optimization programs, relatively common today, provide increased production, increased availability of assets and, in many cases, improved quality. They generally ignore the energy question altogether. Production Energy Optimization combines reductions in energy consumption with production improvements to reduce the cost per unit of production while improving emissions reporting. An energy strategy in mining and mineral processing operations is a critical component of Production Energy Optimization. This strategy must support the financial and operational integrity of the business. Developing a successful energy strategy requires a well structured approach such as following: ??Understanding where energy is being used and why, ??Recommending and implementing energy conservation measures, ??Driving visibility to targets and results, ??Re-evaluating continuously. The objective of this paper is to help you better understand the process, tools and technologies that enable mining organizations today to address energy and sustainability issues more tactically and proactively.

Aug 1, 2013

By Mike Robotham

When RFQ?s are received they often contain detailed technical specifications which suggest a departure from the suppliers own customary approach to the design. Both client and end user are quite rightly influenced by their own experiences. The question is who is right, the client and his consultant, the supplier or perhaps a combination of these. This paper looks at some of the fundamental variances that often occur in the approach to the mechanical design of drum hoists, based on our experiences of recent years. Director of Engineering, Mike Robotham is a chartered engineer and has been with DavyMarkham for over 30 years. Having completed a craft apprenticeship he later joined the engineering department as a junior engineer. He has a wealth of experience of working on medium to large engineering projects in the field of mechanical, electrical and hydraulic equipment

May 1, 2011

By A. H. Lang

"IntroductionMUCH PROSPECTING, exploration, and development work was done for uranium in Canada in 1952, chiefly in northern Saskatchewan and in the Great Bear Lake region of the northwest Territories. The outstanding feature of the year was the great amount of work done in preparing for production at the Ace mine of Eldorado Mining and Refining, Limited, in the Goldfields region . of Saskatchewan. Many private companies and prospectors were also active in this region. Most of the other parts of Canada where uranium has been found received less attention than during the last few years, partly because so much interest was taken in the Goldfields region.In presenting this short summary of the year's activities now, the writer is handicapped because the season is not yet over; some discoveries have probably not yet been announced, and there has not yet been time to digest the numerous reports that have been sent in by companies and prospectors. In any case it would be impossible to give details for most of the discoveries and properties, because that would require a long report, and because that information is classed as confidential until released by the discoverers and companies concerned. It is only possible, therefore, to give a few generalizations, a brief out-line of the activities in northern Saskatchewan, even briefer ,accounts of the work in other parts of the country, and a few details that property owners have informed the writer he may publish or that have already been published by the owners."

Jan 1, 1953

By J. G. Price

"The paper reviews state-of-the art welding processes and consumables for structural and pressure equipment applications in offshore environments, particularly the Arctic. Optimum selection of consumables will be discussed with regard to the facility to meet tentative toughness requirements in weldments. Finally, the development of welding procedure specifications will be considered in relation to the prevention of hot or cold cracking and lamellar tearing.Welding RequirementsGeneralThe exploitation of Canadian frontier oil and gas reserves will require a fleet of various types of offshore structures. These will include fixed jacket types and semi-submersibles for the East Coast with huge man-made islands and icebreakers for the Arctic regions. Both these regions will also require supply and drill ships plus subsea pipelines and cargo tankers for transportation. Clearly the welding of these items will plays large part in the over-all integrity and safety of exploration and production operations.The required development in structural steels and pressure vessel steels, for current and future offshore structures, to improve properties, particularly toughness for lower temperature service, has also prompted welding researchers to develop process and consumable combinations to match the parent plate specifications. This development has had to consider particular aspects of weldability such as a low susceptibility to cold cracking and preventing low HAZ toughness. Current research has centred on attempts to increase HAZ toughness with higher heat input welding of newly developed structural steels.The installation of Arctic region pipelines has provided a sound base for future, more complex fabrications in the most severe service temperatures in the Canadian frontier although few of the installations have been designed to the lowest possible exposed temperature of -62°C."

Jan 1, 1987

By Ahmad Ghahreman, Lin Li

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

Jan 1, 2019

By Ian D. Pirie

Presentation outline ?Project location ?Geology ?Resources and reserves ?Results of the FEED study ?Social and environmental considerations ?Project path forward

May 1, 2010

By William James Kempson

This paper discusses ore handling systems in shafts. These are considered from the loading facility at shaft bottom all the way through to the discharge mechanism in the headframe. These systems will be discussed from the following perspective: i. Intrinsic safety of the systems ii. The efficacy of the systems to perform consistently iii. The maintainability of the systems iv. Overall system cycle times Particular emphasis is placed on the following specific areas: 1. The Shaft Bottom Loading Facilities The various shaft loading systems currently in use are discussed, the selection parameters surrounding these are quantified and the specific selection criteria are outlined. 2. The Various Skip Configurations In this section the various skip configurations in use around the world will be described and the specific design details associated with these will be highlighted. The advantages and disadvantages of these systems will be compared and the overall efficacy of these will be discussed. 3. The effect of the loading and skip configurations on the Load Cycle Times. The overall cycle time which can be achieved by a shaft system is strongly dependant by the speed and efficiency with which the ore can be loaded and transported out of the mine. The potential of the various systems to be optimized will be discussed. The emphasis of this paper is to highlight the lessons which have been learned with respect to ore transport system design and provide a common basis against which these can be compared in future applications.

May 1, 2013

By M. Rizwan

Mine workings are progressing to greater depths as shallow mineral resources are being depleted, and civil engineering projects are nowadays being developed at substantial depths. The threat to tunnel stability posed by rockburst events has increased as a result of these high stress environments. Rockbursts are violent events capable of mobilizing large volumes of rock. In addition to the threat to safety and equipment, rockburst damage can significantly impact on operations, and cause loss of mining production, often the largest cost component of such events. Rehabilitation of such damage requires significant effort and resources. Tunnel walls and roof are usually well supported, but the installation of rock support in the floor is uncommon, particularly in mining environments. In the absence of rock support, floors of the excavations are vulnerable to rockburst damage. New concepts for containing damage of excavation floors by dissipation of the large transient forces using simple techniques or preselected and designed elements of sacrificial floor systems are presented. Two approaches to calculate the demand are presented: estimating load demand by assuming displacement levels and a response modification factor; and using a limit displacement approach to calculate elastic stiffness of the selected elements of the sacrificial support system. The proposed conceptual support systems have the capability of dissipating rockburst energy while retaining sufficient serviceability. It is considered that the concepts presented, for discussion, in this paper are logical and developable into practicable and economic solutions for tunnel floor support in rockbursting environments.

Jan 1, 2015

By Hans von Michaelis

"INTRODUCTIONThe renaissance in gold and silver recovery technology has continued to unfold and it is appropriate to review some of the useful new technologies as well as try to identify some of the industry's future needs and frontiers.The remarkable strengthening in the US dollar has resulted in a relatively low gold price in US Dollars of around $310/oz at the time of writing and silver at $6.25/oz. This general softening in the dollar prices and the recent confusion as to environmental compatibility of cyanidation tailings and effluents, has led to a slowdown in announcements of new operations. Another reason for the slackening off in the USA is that in the past few years a large part of the capital has come from oi I and gas companies that now seem to be losing interest in mineral ventures, and foreign investors for whom the dollar is becoming out of reach. In the author's opinion this represents an unprecedented window of opportunity.Elsewhere in the world where local currencies have weakened, the price of gold is at or close to its all time high.For example, in South African Rands, the gold price was R571.00/oz when the rand was US$1.47 and the gold price reached US$800. Now at US $309/oz and with the Rand at US$0.51 = Rl .00, the local gold price is R600. The price of si Iver in Mexican pesos is not much less than it was when silver reached US$50/oz. Gold, and silver prices in local currencies outside North America are still buovant and at levels where additional investment in new projects is more encouraging.Even in Canada where the dollar is worth about US$0. 75, this provides a smaller but significant cushion compared with US operations. Considering the present strength of the US dollar and even the Canadian dollar relative to many other gold producing countries, there should be significant investment opportunities at today's prices. Mining companies have started to descend on Brazil, for example, where in a matter of just a few years annual gold production has increased from 10 to 70 tons. In South Africa, a Canadian company backed by Swiss financing has been able to take over a Witwatersrand gold mining operation and is installing a huge new tailin9s retreatment plant to process about 1 million tons per month of tailings."

Jan 1, 1985

By B. Haugrud, E. McConaghy, M. Collins, G. Smith

"Laterite ore processed by the Ambatovy Joint Venture in Madagascar is primarily limonitic in nature, containing about 40 to 45 wt.% Fe and 1.1 wt.% Ni. The process selected for treatment of this ore considered the behavior and deportment of iron in each step of the commercial flowsheet. Such considerations included nickel and cobalt recoveries, reagent consumptions, liquid-solid separation characteristics, and both intermediate and final product purities. In this paper, the results for the first three years of commercial operation at Ambatovy are compared with the design parameters, with emphasis on the behavior of iron.INTRODUCTION The main component of nickeliferous laterite ore is iron, and the Ambatovy deposit in Madagascar is no exception. The Ambatovy ore is primarily limonitic in nature, containing about 40 to 45 wt.% Fe and 1.1 wt.% Ni. Since the nickel content of the ore is roughly one fortieth that of iron, successful recovery of nickel depends on close control of the behavior of iron in the selected process. Exploration of the Ambatovy area, which is located to the east of Antananarivo, the capital of Madagascar, dates back to 1960, when the Malagasy Service Géologique carried out a limited pitting and auger-drilling program. Phelps Dodge Corporation (now Freeport-McMoRan Copper & Gold, Inc.) was granted the mining rights to the property in 1995 and carried out significant resource definition, environmental assessment and engineering studies between 1995 and 2001 (Chou, Rooke, Williams, & Hanks, 2000). In 2003, Dynatec Corporation, which was formed in 1997 by the merger of Dynatec International Ltd. and Sherritt International Consultants Inc., signed a joint venture agreement with subsidiaries of Phelps Dodge to evaluate the Ambatovy Nickel Project. Dynatec then became extensively involved in the development of the project, including process selection and pilot plant testing in Fort Saskatchewan (Collins et al., 2004, 2005, 2009; Collins & Vardill, 2005). Dynatec acquired 100% of the project in 2005 and a joint venture between Dynatec, Sumitomo Corporation, Korea Resources Corporation (KORES), and SNC-Lavalin Inc. (SLI) was formed shortly thereafter to provide funding for further development. SLI was responsible for engineering, procurement and construction management of the commercial facilities. Sherritt International Corporation reacquired Dynatec Corporation, including 40% ownership in the Ambatovy Nickel Project, in 2007. The current Ambatovy Joint Venture consists of an integrated nickel and cobalt mining, processing, refining and marketing enterprise between subsidiaries of Sherritt (40% owner and mine and plant operator), Sumitomo Corporation (32.5% owner) and KORES (27.5% owner)."

Jan 1, 2016

By E. Onal

Mining operators are faced with complex information delivered by technology-centric rather than user-centric systems. The ability to achieve high situation awareness (SA) in the face of this data overload is a key challenge for effective decision making and information exploitation. Incidents that result in loss of revenue and even life, and compromise safety that are attributed to human error are often the result of system designs that overload human cognitive capabilities. This paper focuses on defining SA as it relates to mining operations and presents methods for improving SA through a scientific approach for electric shovel operator user interface development.

Aug 1, 2013

By James H. Savory

"In recent years, there has become a growing interest toward a better understanding of balance rope behaviour. With this in mind, the auth or will present a comprehensive summary of field experience, as well as conclusions. In presenting this overview, it is the intent to stimulate further interest as well as provide a framework from which further in-depth investigation can be initiated.Topics which will be covered include rope cores, lubrication practices, loop dividers, rope failures, etc.IntroductionThe first friction hoist was designed in Belgium in J862 by Lemielle. However, it was not until 1877 when Carl Frederich Koepe installed a friction winder sheave at the Hanover Colliery in Germany, that the design was given serious consideration. The winder consisted of a motor-powered sheave over which a single rope was installed, and the end s attached to two conveyance s. Beneath the conveyances a rope was connected, designed to reduce the chance of slip. This was the first balance rope.This earl y mod el is a far cry from the modern tower or ground mounted Koepe winders employed throughout the mining industry today. There have been vast improvements in all aspects of the Koepe winders. One such improvement is in the balance ropes used. This particular area will be concentrated on, with emphasis on selection, maintenance and field experience.SelectionThe sale purpose o f a balance rope is to counter the head rope weight. Obviously then, in selection o f balance ropes, weight is of primary concern. Usually the head and balance ropes are equal in weight. However, sometimes balance ropes which are 5 to 10070 heavier than the head ropes are employed. These reduce horsepower demands during peak acceleration periods, and assist in overcoming inertia during retardation periods. As well, it is sometimes preferred to reduce the balance rope weight, in order to compensate for the eventual weight buildup of lubricant, dirt and debris."

Jan 1, 1983