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By R. J. Visintainer, W. L. Whitlock

"Difficulties with the sizing and operation of centrifugal froth pumps are common and the underlying fluid dynamics are complex. Design and selection often relies on previous experience, offering unreliable guidance for novel applications or unexpected problems. The current paper describes a program of extensive laboratory testing on froth handling centrifugal pumps, covering a range of flows, heads, speeds, viscosity, air content and froth stability. Variations in impeller vane design and the effectiveness of an airlock venting apparatus were also examined. The program resulted in a better understanding of centrifugal froth pump dynamics and insight for the troubleshooting of field applications.INTRODUCTION The Challenge of Pumping Froth In pumping mineral processing froth, the handling of large quantities of air within the fluid is often unavoidable. Efforts to reduce the amount of air present at the pump suction, while always recommended for improving pump performance, may have limitations. Some strategies may also carry an economic penalty, such as unwanted process dilution (e.g. due to water spray or injection), or increased capital cost of equipment due to oversized pumps, sumps and/or piping. Froth pumping losses fall into several categories, as described below and represented graphically in Figure 1. • Density effects: Entrained air reduces the pressure created by the centrifugal pump in direct proportion to the reduction in bulk density. This is not a true “loss”, since the head produced by the pump (in meters of froth), may remain unaffected. However, the reduction in pressure often leads to a corresponding increase in pump speed required to drive the system, which itself leads to increased NPSH required by the pump (NPSHR). Furthermore, by adding a gas phase, the overall volumetric flowrate is increased, assuming a fixed quantity of de-aerated liquid being handled. This leads to increased suction velocity which further reduces the NPSH margin by simultaneously increasing pump NPSHR and decreasing system NPSH available at the pump suction (NPSHA). • Viscosity effects: Increased viscosity introduces an additional factor in some froth pumping applications, such as oil sands bitumen froth. Losses result from increased shear stress within the fluid flow, which increase with flowrate. Viscosity also facilitates the formation of airlock by reducing turbulence and allowing individual bubbles to coalesce more easily within the flow stream. Finally, it increases pump NPSHR by increasing local pressure drop in the vicinity of the vane inlet edges. • Airlock effects: Also known as air binding, it occurs when air or gas coalesces within the pump suction or impeller passages and begins to collect there, held by buoyancy forces within the rotating flow field. In essence, the liquid “floats upwards” towards the pump suction against the outward directed centrifugal forces. The airlock acts as a blockage, with corresponding reductions in flow, head and efficiency. NPSHR also increases, due to increased velocity and distorted streamlines in the flow circumventing the blockage."

Jan 1, 2012

By J. Ran

Ground instability is among the major causes of serious incidents and production disruptions in the mining industry and has a significant impact on safety. Mining companies may have operations in a number of jurisdictions with varied regulatory requirements for ground control management. As these companies expand into countries where mining regulations are formative or lacking clear definition, ground control practices are usually developed by local mine personnel based on their experience. In many cases, inconsistent procedures and standards are generated, which can lead to an increase in occurrence of underground incidents due to difficulties and confusion in implementation. This situation has forced some mining companies to standardize their ground control practices by geographic regions or divisions. Though this approach is an improvement, it may not lead to effective management of ground control issues across all operations of a global mining company. Barrick Gold Corporation, with operations in North and South America, Australia and Africa, decided to adopt a global approach to ground control management. This global approach requires all Barrick operations to prepare and implement an effective ground control management plan (GCMP) based on site specific conditions and company guidelines. It is also required that the GCMP be developed through application of sound geotechnical engineering practices and be consistent with local regulatory requirements and Barrick safety policies. All Barrick underground operations have GCMPs in place, and its surface operations are now involved in the initiative. This paper presents Barrick?s global approach to underground mine ground control management and outlines the content and process for the development of a GCMP.

May 1, 2006

By Réjean Lévesque

SIDBEC-NORMINES a été incorporée en 1976. Depuis la fin de 1977, ses activités comprennent outre la concentration au lac Jeannine, près de Gagnon, du minerai de fer extrait du gisement du lac Fire, I'exploitation d'un atelier d 'enrichissement secondaire et une usine de bouletage à Port Cartier. L 'objectif principal de SIDBEC-NORMINES est de produire six millions de tonnes de boulettes d'oxyde de fer par année, dont trois millions auront une faible teneur en silice afin de répondre aux exigences de la réduction directe. Les installations de SIDBEC-NORMINES sont adjacentes aux installations portuaires de la Compagnie Minière Québec Cartier, à l'est de la ville de Port-Cartier. L 'ensemble est conçu pour produire les deux types de boulettes avec deux circuits d'agglomération installes en parallèle. La production de concentré enrichi (68% Fe et plus) est obtenue dans une usine d'enrichissement utilisant le precédé de séparation magnétique hum ide ahaute intensite (separateurs Jones). À l'usine de bouletage proprement dite, on effectue Ie broyage du concentré et sa mise en boulettes sur disques; l'in duration des deux types de boulettes est obtenue sur deux chaînes d'agglomération Dravo dont chacune a une capacité annuelle nominale de trois millions de tonnes.

Jan 1, 1979

By G. Hausen, H. Micka

"Modern signal and power electronics made adjustable-speed AC drives technically feasible and reliable and economically attractive. Cycloconverters are discussed as a proven technology for mine hoists. \IntroductionUntil rather recent technical and commercial advances in power and signal electronics, DC motors were used almost exclusively for applications requiring continuously adjustable operating speeds and torques. More recently, the significantly higher efficiency and the accordingly lower operating costs of AC motors gained importance. An effective and efficient speed control of AC motors requires the control of AC voltage and frequency. Table 1 shows typical applications of adjustable-speed AC drives.CycloconvertersOf particular interest to the mining industry are cycloconverters for hoist drives. The cycloconverter represents by far the simplest, most efficient and most economical means of converting a constant-voltage, constant-frequency supply into an adjustable-voltage, adjustable-frequency supply as required for the speed control of AC drives operating in the frequency range to half of the utility frequency.Cycloconverters feeding synchronous motors or induction motors are ideally suited for slow-speed direct-coupled drives."

Jan 1, 1988

By Paul J. Bourassa

Alin de pourvoir aux besoins d'hébergement des quel¬ques 1600 employes qui travailleront dans toutes les spheres opérationnelles de l'exploitation du gisement du Mont-Wright, ainsi que de leurs families, Quebec Cartier a dû, avec l'aide de conseillers reconnus, et /a participation de ses employes résidant a Gagnon, étudier tour les nouveaux établissements résidentiels nordiques des dernières années tout au Canada qui dans lee pays scandinaves afin d'être en position de coneepter une agglomeration moderne répondant a toes les besoins de see future résidants. Les pre¬miers residants ont pu passer Noel 1972, et maintenant les logements prévus et construits sont °coupes a 92%.

Jan 1, 1977

By S. E. Daniel

"Due diligence reviews are an essential part of mineral property acquisitions. One of the primary reasons to complete an environmental review prior to exploration property acquisition is to assess the potential environmental liability. It is critical to identify the potential reclamation costs or existing environmental liability associated with the exploration property. A review of the existing condition of the property and its history can allow prioritization of exploration targets and ease future expenditures for historic damages. IntroductionIn Canada and some other jurisdictions, the purchaser of a property is assumed to know, and is (in the absence of deceit or fraud) financially responsible for, what is purchased. A plea of ignorance, at least from the perspective of environmental liability, is not an acceptable excuse to avoid responsibility (Nelson, 1994). Therefore, if an exploration company (for the purposes of this paper, any organization conducting exploration work) purchases a property that has environmental contamination, the new owner is liable for the cost to reclaim the site to an acceptable level. The cost to reclaim the site is the environmental liability. The new owner is responsible for existing environmental liability of the property, even if the exploration company’s personnel were not aware of the problem. In simplest terms, buyers beware. Therefore, in order to protect the exploration company’s interests, the exploration manager should determine the characteristics of the property of interest prior to purchase or other involvement, and exercise due diligence.The term “due diligence” is often used in the mining industry. To ensure clarity, in this paper’s context, the author has chosen to use the following meaning: “… due diligence is used to describe a detailed data review, generally in connection with the purchase or sale of a mineral property, the approval of a large capital expenditure, or the borrowing of a large sum of money” (Smith, 1997).Directors of the exploration company are held liable for the decisions made, unless they have relied in good faith on,“…a written report of the auditor, or a report of a lawyer, accountant, engineer, appraiser, or other person whose profession lends credibility to a statement made by any such person” (OBCA, 1994)."

Jan 1, 2003

By D. E. Calisaya, É. Poulin, A. Desbiens, R. del Villar, A. Riquelme

"A 15 cm diameter by 732 cm height, fully automated pilot column was installed in the Agnico-Eagle’s Laronde concentrator (Québec), for evaluating the performance of newly developed sensors and advanced process control algorithms. For eventual comparison purposes, the pilot column is continuously fed with the same slurry feeding the copper-circuit third cleaner column. It is equipped with electrical conductivity-based sensors for estimating the three variables used in the multi-variable control algorithm under evaluation: froth depth, fraction of wash water underneath the interface and gas hold-up. Froth depth is regulated using a PI controller while a predictive controller is formulated as the minimization of the tracking errors of gas hold-up and bias rate, keeping several operating constraints between their practical upper and lower limits. In particular, an unreachable high set point of gas hold-up can be selected in order to maximize the bubble surface area available for particle collection, while maintaining bias rate above a minimum value required for froth cleaning. The proposed strategy may indirectly help optimizing flotation column operation by using these secondary variables, without the implementation of a real-time optimization layer.INTRODUCTION Flotation columns have already been used for more than 30 years, mainly in cleaning stages, as a result of their froth washing capabilities. Despite their widespread usage, the measurement of some pertaining variables and their use for automatic control is rather scarce. Among the most important variables directly related to the process metallurgy (concentrate grade and recovery), froth depth (hf) is the only one normally monitored and controlled. Even though commercial sensors are available, gas hold-up (eg), a variable directly related to concentrate recovery, is seldom measured and never controlled. Another important variable, bias rate (Jb) responsible for concentrate cleaning, is simply not measured at all, as there is no commercial sensor available. Therefore, besides froth depth, continuous monitoring of process variables is limited to flow rates (gas, feed, tailings, wash water), i.e. to manipulated variables. Some new available sensors have been industrially tested, e.g. the Sonar-TracTM for eg (O'Keefe, Viega & Fernald, 2007) and the McGill hold-up sensor (Tavera & Escudero, 2002). Others, for bias rate and frother concentration, have been successfully validated at laboratory scale by Laval’s LOOP researchers (Maldonado, Desbiens, del Villar & Chirinos, 2008b; Maldonado, Desbiens, del Villar & Aguilera, 2010a). Some devices have been extensively used for monitoring bubble size and space distri-bution, e.g. McGill bubble viewer (Gomez & Finch, 2007) and others."

Jan 1, 2012

By Tim Edwards, Richard Triglavcanin, Ian Arbuthnot, Darren Colwell, Brad Garraway, Ken Roberts

"In the mineral processing industries, there is an increasing need to design thickeners which are able to produce high density underflows usually referred to as “paste”.The behaviour of a flocculated suspension in compression needs to be well understood in order to arrive at a reliable thickener tank configuration (i.e. diameter, cone angle and depth) for a required paste result.As a suspension approaches paste consistency, it’s fluid characteristics change markedly. It develops a high yield stress, and may have an increased tendency to form agglomerates, which lead to a phenomenon known as “rotating beds”, “donuts”, or “islands”. These characteristics present challenges to the designer of the rake mechanism.The subject paper addresses the requirements for designing a paste thickener, covering the following topics:o Testwork for thickener sizingo Design of rake mechanismso Suspension rheology and effect on designo Case studiesTESTWORK AND SIZING FOR PASTE THICKENERSThickening slurries to the maximum possible density (paste) is becoming increasingly common. Applications such as Autoclave feed thickeners, paste backfill and some counter current washing (CCD) circuits are all examples of potential paste thickening applications. The principle of paste thickeners is that the compression zone is much deeper than on either high rate (HRT) or high compression (HCT) units; generally 3 metres or more. As the compression zone gets deeper, theunderflow density for a given flux rate (tph/m2) increases, as a result of two factors:1. Longer bed settling time. Settling flocs move relative to one another and release interstitial fluid when they are in compression. Increasing bed residence time achieves higher density underflow as more fluid is removed.2. The nett weight of the bed creates a compressive force on the settling flocs. This force increases with depth, so that the flocs at the bottom of the bed experience the highest compressive force. This represents the driving force to expel interstitial fluid and hence increase bed density."

Jan 1, 2005

By J. Andrew Cornier, Mike Cooper

"Upon successful completion of the AG/SAG Mill project (Cooper et al., 2001) the Brunswick Mine concentrator was configured with single line processing through the AG/SAG mill, followed by two parallel ball mill and flotation circuits. The Stage Grinding project was undertaken to utilize a pre-flotation stage on the AG/SAG mill primary cyclone overflow and simplify the flowsheet by consolidating the two ball mill and flotation circuits, resulting in single line processing fi-om AG/SAG mill to final concentrate. Concurrently, the reclaim water supply capacity was increased to enable flotation cleaning at lower percent solids.Benefits from the Stage Grinding project include revenue enhancement from increased zinc grade and recovery combined with additional lead recovery. Further benefits included a reduction in the number of process pumps, reduction in loss associated with spillage to sumps and process simplification through efficient use of equipment layout.The Stage Grinding project was implemented in six phases over a period of seven months in 2000. Each phase was commissioned during scheduled concentrator shopdays with minimal additional downtime required. One year after project approval the Stage Grinding project was completed at a total cost of $1 1.8 million.INTRODUCTIONThe Noranda Inc. Brunswick Mine, located near Bathurst, New Brunswick, is one of the world’s largest leadzinc mines. Milling of ore began in 1964 from the No. 12 orebody, with an expansion in 1966 to accommodate ore fkom the No. 6 open pit located several kilometers away. In 1980 the pit was exhausted and the concentrator rationalized to accept a design feed rate of 10,500 tomes per day from the No. 12 mine. In excess of 100 million tomes have been milled to date, representing over three-quarters of the known reserve. The concentrator employs differential froth flotation to produce lead, zinc, copper and leauzinc bulk concentrates. The ore is massive sulphide, with approximately 20% valuable minerals, 60% pyrite and 20% silicates."

Jan 1, 2002

By L. Connolly, F. R. De Luca

"Rubber liners at Denison Mines Limited are used in 10 1/2x 24' low discharg0 pebble mills. These were originally 10 1/2 x 13 Dominion overflow type ball mills. Experience here shows that the wear of rubber and ni-hard lifters is approximately the same in the feed end half of the mill, while the wear of rubber lifters is much greater in the discharge half. The wear of rubber plates is considerably less than white iron in the feed end half of the Mill and slightly more in the discharge end half of the Mill. Rubber components are lighter to handle but their installation is time consuming. This leads to the conclusion that a combination of ni-hard lifters a~~ rubber plates is the most economical compromise in Denison's case, for the Mill. Rubber discharge grates are superior to steel grates, while steel feed end liners are superior to rubber.The Use of Rubber Mill Liners at Denison Mines LimitedGrinding is done in two identic0al circuits each consist-ing of one 10 1/2 x 14' Dominion overflow rod mill, two Dorr Oliver quadraplex rake type classifiers, two 10 1/2 x 24' Dominion low discharge grate pebble mills and ancillary pumps and conveyors for pebbles. There is one centrally located distributor box that receives the discharge of the 4 pebble mills and splits it out to the classifiers."

Jan 1, 1974

By Tapio Leskinen

"l. IntroductionA reliable sampling system is the basis for an on-stream analyzer. This was realized in Outokumpu company when the development work of the Courier 300 On-Stream X-ray analysis system was started. Because Outokumpu Oy is a mining and mineral processing company, its engineers have been able to thoroughly test sampler prototypes in actual operating situations. The sampler development has been going for several years in close co-operation between company's concentrators, the Institute of Physics and the Instrument Division of Outokumpu Oy. The most active part of the work was done between 1969- 1972. Besides the reliable operation of a sampler special attention was paid to the representatively of the samples taken by the samplers. 2. The Courier 300 Sampling SystemThe sampling system comprises up to fourteen sampling circuits in one Courier analysis system. Each circuit consists of the following components:1. Primary sampler 2. Secondary sampler 3. Cleaner screen 4. Feeding tank5. Sample cell6. Timer-controlled sampler7. Pumps, sumps and pipesSecondary samplers, cleaner screen and feeding tanks are included in the secondary sct1npling system. The sample cells are located in the spectrometer cabinet of the analyzer."

Jan 1, 1976

By Nicole Peter

When introducing digital training technology a practical approach helps address cultural concerns.  Solutions to help create acceptance are discussed.  Resistance to change may be deeply rooted in traditional mine training personnel.  Traditional training staff members may consider themselves less digitally-savvy and resist technological methods available to them. A transitional approach intended to help mitigate or resolve resistance is presented as a continuous improvement pathway toward full adoption.  This presentation contends every mine should welcome the benefit of a digitally connected critical enabler.  The adoption of a digitally savvy learning centre is often viewed a disrupter to existing practice.  Given a commitment-driven learning centre model, technology offers the opportunity to transition from a compliance-based training model to one of competence.  Learning and Development practitioners should welcome the latest advances in neuroscience, Bloom’s taxonomy of learning model, and principles which guide mine safety training as outlined by the Lowell Institute for Mineral Resources at the University of Arizona. By employing digital applications to include animation, game-based simulations and immersive Virtual Reality (VR) these technologies create a viable digitally-savvy learning centre. We will outline the ingredients of a digitally enabled, or VR, Learning Centre to offer some observed benefits, successes, and potential short-comings. Much excitement in the industry surrounds implementation of simulation and/or VR headset training.  Given fair consideration of these as a ‘fit-for-purpose’ solution we examine the paradigm shift required to create real results for on-the-job learning.  Interim steps may be needed to meet the cultural transformation.   Simpler forms of VR, in the form of 3D models and VR environments as displayed on a large interactive touch screen, can serve to bridge this challenge and address a group learning environment. Features of the interactive 3D technology and ease of adoption are presented.  Usage of the touch screen is similar to that of a smart phone. It may be implemented as an obvious transitional tool.  To help describe merits of the interactive touch screen the presentation points out these sample underground and surface mine training applications. There are 3-D simulations such as ventilation, emergency response, support installation, and mine cycle and activity scheduling programs. These applications offer the ability to conduct entry examinations, complete digital pre-use checklists, and perform planned task observations in the virtual world of work. The tool may be used to teach the flow of hydraulics and do fault-finding on machinery such as loaders and dump trucks. Learners may navigate in a virtual mining environment to identify hazards, detect and assess abnormal ground conditions, address poor design features, and alleviate traffic constraints. It is possible to use connected physical controls to navigate machinery in the virtual environment. We conclude the presentation with a “compare and contrast” approach to cite potential cultural benefits by adopting a transitional method. 

May 4, 2025

By Jason J. Crowder

Presentation Outline ? Introduction ? Costs of ground support and rehabilitation ? Why post-failure rock mass properties are necessary ? The Rock Mechanics Problem ? Present State of Modelling and Instrumentation in Mining ? Case Study Background ??Williams Mine ? Deriving Parameters for Modelling from Instrumentation ? Results from Case Study ??Back Analyses ? Discussion of Research Impact t Summary

May 1, 2006

By G. M. Ritcey, K. E. Haque, S. H. Lucas

"Laboratory-scale hydrochloric acid leach tests were conducted on an Elliot Lake uranium ore. Hydrochloric acid leaches without an oxidant or with molecular oxygen (i.e., air or pure oxygen gas) as an oxidant favoured uranium and radium extractions. Conditions for maximum uranium, thorium and radium extractions with hydrochloric acid in the presence of sodium chlorate were determined. The highest extractions of uranium (96%), thorium (81%) and radium (91%) were obtained using a mixture of 44.0 kg HCI and 2.5 kg NaCIOJ per tonne of ore at 75°C with 18 hours ' retention.Flowsheets for two-stage leaching are proposed. The residues obtained from the second-stage leach contain uranium (0.002%), thorium (0.006%) and radium (15 to 20 pCi/g). Tailings of this nature are considered suitable for mine backfill, and, if pyrite is removed, suitable for surface disposal.IntroductionThe nuclear energy industry forecasts an increasing demand for uranium. This increasing demand requires not only largescale mining and processing of conventional and complex uranium ores, but also leads to the consideration of new and nonconventional sources of uranium, e.g., black shales, phosphate rocks, granite, sea water and fossil-fuel ash."

Jan 1, 1980

By Karl Marquis

La Mine Mouska exploite depuis deux ans certains blocs de réserve à l?aide de la méthode long trou. Même si, à priori, la méthode long trou semble rentable, le contrôle de la dilution ainsi que le respect d?un échéancier serré s?avèrent primordiaux afin que cette méthode d?exploitation puisse être justifiable économiquement. La présentation suivante fera la comparaison économique entre cette méthode et celle de chambre-magasin.

Oct 1, 2001

By J. E. Scott, L. M. Heaman, R. A. Creaser, G. S. Salazar

"Schaft Creek is a calc-alkaline porphyry Cu-Mo-(Au) deposit located in northwestern British Columbia. The deposit formed in a volcanic arc setting, likely on a back-arc rifted continental fragment. It is hosted by Late Triassic basaltic to andesitic volcanic rocks of the Stuhini Group (Stikine Terrane), and is associated with porphyritic granodiorite dikes emanating from the nearby Hickman batholith. The age of the Hickman batholith is approximately constrained here by a composite U-Pb zircon date of 222.1 ± 9.6 Ma, which is in broad agreement with a well-constrained age for mineralization at Schaft Creek of 222.0 ± 0.8 Ma (Re-Os molybdenite). The deposit is in most respects typical of calc-alkaline porphyry systems, but displays silica-poor sericite-chlorite alteration in mafic country rocks in place of classic phyllic altera¬tion. The deposit comprises three distinct, but related, zones: the northern Paramount zone, the Main zone, and the West Breccia zone. Two phases of mineralization are observed. The first phase occurs as hydro-thermal veins and breccias, and minor disseminations. It consists of bornite, chalcopyrite, molybdenite, and pyrite with potassic and sericite-chlorite alteration. The second phase is minor and consists of veins of molybdenite ± specularite, as well as Cu-Pb-Zn sulfide veins without any significant corresponding alteration. Extensive structural modification has affected the deposit both during and after its formation.Schaft Creek est un gîte porphyrique de Cu-Mo-(Au) calco-alkalin situé dans le nord-ouest de la Colombie Britannique. Ce gîte s’est formé dans environnement d’arc volcanique, probablement situé sur un fragment continental bordé par un bassin d’arrière-arc. Le gîte est encaissé par les roches volcaniques basaltiques à andésitiques du Groupe de Stuhini (Terrane de Stikine) d’âge Triasique tardif, et est associé à des dykes de granodiorite porphyrique provenant du batholithe de Hickman avoisinant. L’âge du batholithe de Hickman est estimé par un âge U-Pb composite sur zircon de 222.1 ± 9.6 Ma, lequel est grossièrement en accord avec l’âge de la minéralisation de Schaft Creek, estimé a 222.0 ± 0.8 Ma (Re-Os sur molybdénite).Ce gisement, bien qu’à plusieurs égards typique des systèmes porphyriques calco-alcalins, présente une altération en séricite-chlorite pauvre en silice dans l’encaissant mafique a la place de l’altération phyllique classique. Ce gîte comprend trois zones distinctes bien que connexes : la zone Paramount au Nord, la zone Principale et la zone West Breccia. Deux phases de minéralisation sont observées. La première phase se présente sous forme de veines et de brèches hydrothermales ainsi qu’en disséminations mineures et consiste en bornite, en chalcopyrite, en molybdénite et en pyrite avec une altération potassique et en séricite-chlorite. La seconde phase est mineure et consiste en veines de molybdénite ± spécularite ainsi qu’en veines de sulfures de Cu-Pb-Zn sans association à une altération particulière. Le gisement a été profondément modifié par la déformation a la fois durant et après sa formation."

Jan 1, 2008

"The Ernest Henry Mining (EHM) ore body is an iron oxide copper gold deposit with an average grade of 1.1 percent copper, 0.5 g/tonne gold and 22 percent magnetite. At the end of 2009, EHM converted the ball mill media charge from forged steel to high chrome media. At high pH values (above 10.5), forged media is passivated, so as the pH of the system drops the media corrosion rate increases and floods the system with corrosion products, affecting flotation. As the high chrome media is much more inert, pH has less of an effect on copper flotation response. Given this, the pH in the roughers was dropped from 10.6 to 9.6 and it was found that there was a slight increase in copper recovery and no statistical change in either the rougher or final copper concentrate grades for copper and gold. With the reduction in pH, there was a noticeable reduction in lime usage from 0.85 kg of lime per tonne of ore processed to 0.55 kg/t. This reduction in lime is equivalent to approximately $700,000 per annum at current production rates.INTRODUCTION The Xstrata Copper Ernest Henry Mine (EHM) is situated 38 km north east of Cloncurry, Australia. The mine began as an open-cut operation in 1998 and transitioned to a multi-sourced operation in December of 2011, utilising ore from the newly completed underground mine in addition to ore mined from the Mount Margaret Mining operations. EHM produces a combined copper gold concentrate containing 25 000 t of copper and 35 000 oz of gold annually, utilising a three stage grinding circuit along with a four stage flotation circuit. In addition to this EHM also produces 1 000 000 t of magnetite concentrate annually via a further grinding and three stage magnetic separation circuit. Based on metallurgical test work performed by Magotteaux between 2002 and 2008, the step to change from forged steel media to 18 percent chrome media was taken in 2009 in a bid to alter the pulp chemistry to improve the flotation performance in the plant (Greet, Kinal, Twomey, & Peatey, 2010). This plant trial resulted in: • Increased dissolved oxygen levels within the pulp, • A ball mill discharge Eh shift of 25 mV to more oxidising pulp potentials, and • An EDTA extractable iron percentage reduction. These improvements in the pulp chemistry resulted in an increase of 1.7 ± 0.6 percent in copper recovery and an increase of 2.9 ± 1.7 percent in gold recovery. As the plant trial using high chrome media was successful, the use of the media was adopted as the standard for the ball mill. This implementation opened the door for further process improvements around the flotation circuit."

Jan 1, 2014

By Q. Zhang, J. A. Finch

"Sphalerite flotation in the absence of copper activation at moderately alkaline pH has been observed in laboratory studies. An in-plant test of this observation was conducted at Kidd Creek Mine LTD. using a portable minicell flotation circuit. The results confirm that raising the pH causes sphalerite flotation.The testwork with the minicell circuit is described. The circuit, built around 2, 51 cells donated by the Noranda Technology Centre, was funded by Air Liquide and NSERC. It includes a data acquisition system to monitor continuously dissolved oxygen, pH and Pulp potential.INTRODUCTIONFlotation of sphalerite is normally practised by adding CuSO4 as an activator under alkaline pH. Recently there have been a number of laboratory and plant examples of sphalerite flotation without deliberate addition of cu++ ions (Girczys, 1972; Mukherjee, 1976; McTavish, 1980; Marouf et al., 1986; Mielczarski, 1986; Leroux et al., 1987; Palsson and Forssberg, 1989; Sandoval-Caballero et al., 1990; Zhang et al., 1991).In batch tests, with a sample of Pb/Zn ore from Polaris, Leroux et al. (1987) found that sphalerite became floatable after adjusting pH to 9. 5-11: they ruled out natural floatability or the formation of elemental sulphur on the surface but suspected iron hydroxy compounds were responsible. Sandoval-Caballero (1990) conducted a continuous minicell test at Brunswick Mining and obtained a 44 % Zn recovery and 40.5 % Zn grade concentrate without deliberately adding CuS04 at pH= 10.5. With single mineral studies, Zhang et al. (1991) revealed good sphalerite floatability (over 80% recovery) in pH range 8 to 11 and found that this floatability was related to pH, dissolved oxygen (DO) level and Fe++ species present in the system.To explore further the conditions under which sphalerite can float without addition of CuSO4 , a continuous pilot test using minicells was performed at Falconbridge Ltd., Kidd Creek division. The set-up is briefly described (a more detailed description is given elsewhere in these proceedings) with emphasis on the data acquisition system - dissolved oxygen, pulp potential and pH were monitored continuously. Results of testwork investigating pH, CuS04 addition and gas composition are presented."

Jan 1, 1992

By Jeffrey L. Pagnutti

Train derailment can lead to loss of capital, damage to the environment, and loss of life. Machinery condition monitoring techniques can be used to develop a structural health monitoring system for railway track to detect faults at the incipient stage, before catastrophic failure occurs. This study uses vibration measurements from a novel material haulage unit to develop a decision support system for railway track maintenance. A variety of feature sets and classifiers were compared to determine the optimal configuration for fault detection. The results highlight the shortcomings and advantages of certain methods and describe the process in which the optimal result was obtained. The Parzen data descriptor paired with a refined statistical feature set performed the task of fault detection with less than five percent false positive and false negative classification error. Overall, the outcome of these experiments indicated that condition monitoring of railway systems is a promising approach for fault detection and has the potential to avoid catastrophic failure.

May 1, 2013

By Staff

This paper contains an outline of the history of the Sullivan mine, now owned and operated by the Consolidated Mining & Smelting Company of Canada, Ltd.; some account of the various methods by which the ore has been treated in efforts to solve the metallurgical problems which its complex character presents, and, finally, to give, as concisely as possible, an outline of the present mining and metallurgical practice along with a description of the mining and milling plant at Kimberley and the smelter and refineries at Trail, in British Columbia. EARLY HISTORY In May, 1892, Pat Sullivan, John Cleaver and Mike Holland left the Coeur d'Alene country, in the State of Idaho, to seek their fortunes in the Kootenay lake district in British Columbia. They were aided in their venture by James Cronin, afterwards locator and owner of the St. Eugene mine at Moyie. Two months later the party broke up, Sullivan and Cleaver crossing the mountains from Crawford bay on Kootenay lake to the head waters of the St. Mary's river, the course of which they followed down to Fort Steele. Here they found a good deal of excitement about the North Star mine, and, joined by "Ed." Smith, who was familiar with this part of the country, they determined to return and prospect in its vicinity.

Jan 1, 1924