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By Sam Palombo, James José Varela

"Washing can be defined as the process used to eliminate or reduce the dirt (presence of fines or slimes) of one material. It is also the basic and oldest process applied to ore preparation for further concentration. This process, in combination with commnution and screening, form the so called washing plant and in many cases produce end products. This work describes the factors that influence the performance of the washing process and main washing technologies used in the mineral processing industry.The Hydro-Clean represents, since 1998, a state of the art technology in this area and is comprised of one of the most innovative solutions developed at HAVER & BOECKER. HAVER & BOECKER design and manufacture technology for mining and related industries. Today the Hydro-Clean is manufactured and sold throughout the Haver Screening Group (HSG) which is comprised of HAVER & BOECKER Maschinenfabrik Münster, HAVER & BOECKER Latinoamericana – Brazil and W.S. Tyler Canada.The Hydro-Clean is a washing technology based on utilization of high pressure water jets. To follow we will discuss how the Hydro-Clean’s different modes of operation result in several advantages related with mine waste reduction, recovery of saleable product, lower capital costs, superior washing results, less stress for the material, a wider range of application and less maintenance cost. Aside from these positive factors, its lower operation costs related to the consumption of energy and water are presented. It is important to note that the quantities, tonnages, data and management concepts presented in the paper are accurate for the time of writing and are subject to change and modification as operations progress."

Jan 1, 2009

By Mostafa Benzaazoua

Les remblais en pâte cimentés sont de plus en plus utilisés dans les exploitations minières souterraines. Une autre alternative d?utilisation du remblai en pâte consiste à le pomper et à le stocker dans des empilements de surface. En plus d?avoir des avantages d?un point de vue de stabilité physique des ouvrages, le remblai en pâte cimenté en surface permettrait également de stabiliser les contaminants dans la matrice du remblai à l?aide du processus de solidification et de stabilisation. Dans cette étude, des remblais en pâte constitués d?un résidu minier sulfuré renfermant beaucoup d?arsenic et de différents liants ont été testés afin d?évaluer la stabilisation des contaminants dans la matrice de remblai. La méthode utilisée pour évaluer la stabilisation et la solidification des contaminants est le test de lixiviation en extracteur de Soxhlet. Les résultats géochimiques issus de ces essais ainsi que la caractérisation chimico-minéralogique des remblais lixiviés ont été analysés pour comprendre les phénomènes chimiques présents dans les remblais durant le temps de cure. Les résultats obtenus montrent que les sulfures présents dans les remblais étudiés (pyrite FeS2 et arsénopyrite FeAsS) s?oxydent et provoquent la dissolution des hydrates les plus vulnérables (dissolution de la portlandite Ca(OH)2 et/ou décalcification des gels CSH). Le calcium produit permet de précipiter les sulfates (essentiellement sous forme de gypse plus ou moins hydraté) et l?arsenic sous forme d?arséniates de calcium plus stables. Les différents liants utilisés donnent des résultats différents en termes de stabilisation et de solidification qui seront discutés dans cet article.

Nov 1, 2002

By Timo Niitti, Antti Rinne, Janne Turunen, Sami Grönstrand

"This paper describes novel methods to enhance the flow dynamics of a mechanical flotation cell that can be applied to an existing installation. There are several reasons to alter the flow dynamics. The most common motivation is to improve the metallurgical performance of the cell, for instance, to improve the flotation recovery in particle size ranges that are normally difficult to recover.The flow dynamics enhancements are associated with the geometry of the rotor-stator area and additional features in the tank. The rotor-stator area has been modified to provide more concentrated turbulent kinetic energy or respectively more pumping efficiency with less attrition to the slurry. The tank can be fitted with various geometrical features, aimed to create a desired particle suspension profile. Depending on the targeted particle size range and application, badly selected or designed features can also have a negative effect on the metallurgical results.Besides new flotation equipment, the enhancements can be applied to existing flotation cell installations, thus enabling improvements in the mixing profiles, solids suspension, tank sanding and metallurgical performance of operating flotation circuits. Results of several tests carried out in existing plant operations are presented, concerning both flow variables and metallurgy.The common factor to above-mentioned enhancements is the use of modern computational fluid dynamics tools in the design phase, as well as the validation of the obtained CFD results in laboratory and production scale. Validated variables include mixing profile, power draw and local air hold-up.The paper demonstrates the effects of various flow geometries on the mixing profiles and metallurgical results of existing mechanical flotation cells. It shows how modern computational fluid dynamics analysis can be used to screen and select different approaches before carrying out costly trial-and-error experiments in plant scale."

Jan 1, 2006

By Kevan Ford, Getulio Junior, Rob Henderson, Wayne Philips, Chris Martin, Rob Thorpe

"Plant 2 at the Kinross Paracatu gold operation in Minas Gerais State, Brazil, was commissioned in late 2008. Designed to be the largest tonnage, lowest grade gold milling operation in the world, Plant 2’s throughput has steadily increased towards its design capacity of 5087 tons per hour.The plant employs a gold-specific flotation scheme to recover the majority of gold, which is present as discrete free gold particles. Additional gold is recovered by jigs in the grinding circuit, and the jig concentrates are reground, upgraded and subjected to intensive cyanide leaching. The flotation cleaner concentrate is reground and leached using a conventional CIL circuit.One year after start-up, with the plant stabilizing operationally, plant circuit surveys were completed by a joint team from Kinross Paracatu and Blue Coast Metallurgy Ltd. The surveys audited the flotation and concentrate treatment circuits to investigate the metallurgical performance.This paper describes the Plant 2 operation and how the surveys were designed and executed. Some of the quality control systems that were employed to provide meaningful data from such a low grade gold ore are described and findings and actions taken to improve metallurgy as a consequence of the surveys are discussed.INTRODUCTIONThe Paracatu mine is located two kilometres north of the city of Paracatu, in the north western portion of the state of Minas Gerais, Brazil, 230 km southeast of the national capital Brasília (shown in Figure 1). The present day Paracatu mining operation, fully owned by Kinross Gold, through its Brazilian subsidiary Rio Paracatu Mineração (RPM) is designed to be the largest tonnage, lowest grade free milling gold operation in the world.The deposit currently hosts some 1.2 billion tonnes of ore at a grade of ~0.41 g/t gold, hence contains a total gold reserve of over 20 million ounces. At a designed plant throughput rate of 61 Mt/year the mine life goes beyond 2030."

Jan 1, 2011

By Ning Shi

This paper suggests an alternative design approach for an innovative shovel dipper, for use in ground conditions where cutting of virgin ground rather than scooping of blasted material is required. Not only does the new design have an optimized dimension ratio (width:height:depth) and attachment arrangement (angle, position), but also a non-linear pro¯le in 2D and 3D. The approach is based on the simulation of a shovel's duty cycle to verify a pilot dipper model. In order to achieve a realistic simulation that could be used to evaluate a dipper design, the model is e®ectively a descriptor of actual shovel activity under soft ground conditions. The shovel geometry, motion and operation, with an emphasis on digging and dumping kinematics and dynamics are the principal elements of the simulation. The simulation considers a fresh face location, repeating tucking, digging and dumping swing motions within the geometric range of the machine, ending when no more face material remaining within reach without re- positioning. The simulation yields digging force, friction force, trajectory, ¯ll time, ¯ll factor, etc, which may be integrated into two basic considerations: power draw (output) and volume delivered (production), as indicators of dipper performance. The simulation has been used as a tool to modify an existing dipper design, prior to looping further simulation cycles. Ultimately, an optimized or totally-new-concept shape is realized. A prototype dipper as a fractional scale model will be built to verity the performance under actual mining conditions.

May 1, 2004

This paper describes the back analysis of the Pavoncelli tunnel, an hydraulic tunnel which was excavated between 1904 and 1915 in South of Italy and experienced severe damages during the 1980 Irpino-Lucano earthquake. A numerical simulation which is intended to study the behaviour of the tunnel during this seismic event is presented, also accounting for the swelling phenomenon that took place during and after construction.

May 1, 2009

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 Gunnar Nord

Introduction ??Atlas Copco has customers both amongst Miners and Contractors ??We believe that the contractor's approach to tunnelling is worthstudying ??For a tunnel contractor the incentive is speed as ?30 % of the costs are material related ?70 % of the cost are time related ?A tunnel contractor favours utilizing of the face ?A miner favours utilizing of the gear ??Statement; In mining, a long term average advance rate of more than 10 m / day can be achieved with the excavation techniques availabletoday

May 1, 2009

By A. R. House, G. W. Shepherd

Newmont USA Limited owns and operates the Phoenix Mine near Battle Mountain, Nevada, USA. The existing milling facility has operated since 2006 (House, 2010). Following the startup of the milling operation, and coupled with the upswing in the copper market, Newmont realized that Phoenix had no process option to treat transition and oxide copper ores. This meant that potentially revenue generating ore would be mined as waste. With no system in place to treat the transition and oxide copper, work began to determine the most feasible approach. After evaluating multiple options, the flow sheet was set for a runof- mine (ROM) heap leach pad and solvent extraction/ electrowinning plant (L-SX/EW). This paper will discuss the eight years of successes and challenges with developing the copper L-SX/EW plant and achieving commercial production of copper cathode.

Jan 1, 2014

By Corby G. Anderson

"Laboratory testing, plant optimization, and the interpretation and application of metallurgical technologies can be tedious, time consuming and costly. This paper outlines the use of proven statistical design of experimentation software for rapid laboratory testing and optimization of operating plants with limited representative sample utilization. This results in less costly required testing, a more thorough understanding of results and the ability to simultaneously optimize several variables and outcomes at once. At the Center for Advanced Mineral and Metallurgical Processing (CAMP), this testing methodology has been used successfully in many metallurgical development and plant optimization projects thereby confirming its real world utility and application. Accordingly, several applied examples in flotation and hydrometallurgy will be outlined in this paper. This will include flotation testing of a copper gold ore, flotation testing of a copper, cobalt and gold ore, optimization of an industrial hydrometallurgical jarosite circuit and optimization of industrial nitrogen species catalyzed pressure leaching of a copper enargite concentrate.INTRODUCTIONWhile flotation technology is now 100 years old, the testing, interpretation and application of lab results can be tedious, costly and time consuming requiring extensive sample collection and preparation. In addition, recent applications like hydrometallurgical pressure leaching and associated unit operations, such as precipitation, still remain more of an art than a quantifiable science. This paper will elucidate the application of STAT-EASE Design-Expert software to minimize required laboratory testing while rapidly optimizing multiple results and outcomes in a statistically valid manner. The STAT-EASE program is based on proven design of experiment fundamentals. In this paper, the real world application of this methodology for lab testing, plant optimization and process development will be elucidated."

Jan 1, 2006

Brunswick Mine employs an ore and waste pass system for material transfer. This paper reviews the evolution and performance ore pass systems at the mine. It presents the range of selected configurations, inclination, dimensions etc. Select case studies are used to address the influence of structure, stress and materials handling on the longevity of the employed ore passes.

Feb 1, 2008

By Rob Stewart

Acknowledgements ? Josef Macek(Manitoba Geological Services) ? Sally Goodman (SRK) ? Inco Geologists ? Rogerio Montiero ? Thompson Mine Geologists Introduction ? Regional Geology ? Thompson Geology ? Stratigraphy ? Sulphide Characteristics ? Conceptual Model ? Structural History ? Belt ? Thompson Mine ? 1D Deposit ? Ore Controlling Structures ? Using Structural Data to Guide Exploration ? Summary

May 1, 2006

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

Jan 1, 1990

By Tom C. Palangio

The mining industry has come to rely on imaging devices to monitor and record all kinds of activities. We use them to measure, improve the process, ensure security, increase production and automate machinery. Cameras can be installed in locations most people wouldn?t want to live and be our ?eyes? to record the events at that location. This paper discusses digital imaging, the equipment, methods, techniques and information that can be learned from digital devices used in mining operations. The guy who said ?a picture is worth a thousand words? probably understated it. Images are the perfect way to document conditions before, after and even during mining activities. Today?s wide choice of cameras, camcorders and other digital devices allow us to record most activities and events. The technology is advancing at a high rate. Digital cameras and camcorders are marvels of technology with high resolution optics, compact size, automatic time and date stamp, great battery life, shutters to freeze motion and computers to auto focus and eliminate jitter (image stabilization). Add to this the economical price and ease of use and everyone in this industry should be aware of the possibilities.

Oct 1, 2010

By M. L. Goble

"Inco Metals Ltd. (Manitoba Division) operates a mining, milling, smelting and refining complex, 500 miles north of Winnipeg in central Manitoba. The Thompson Mill is presently operating at 12,000 S.T.P.D. on ore from both underground and open pit mines. The ore is treated in two separate milling and flotation circuits utilizing a common crushing system which is located inside the main mill building. The milling facility employs approximately 43 operating employees, 30 maintenance employees and 20 staff in supervisory or process development roles.In recent years an increasing awareness of the potential hazards of contaminants in the work place has made it mandatory that all employers maintain careful and accurate records of the work environment to which each employee has been exposed during his working career.The importance of this record keeping and general observation of the work place cannot be over emphasized. Proper monitoring of the work place provides an accurate and complete record of the contaminants and physical agents to which an employee is exposed during his work career. This can aid in studies which might be conducted in the future and can also be used as a basis for instituting improvements to the workplace."

Jan 1, 1980

By M. H. Moys, J. A. Finch, A. R. Laplante

"A detailed review of ball milling circuit control practices in industry has been carried out. Based on fundamental process performance objectives, a standard system for base-level control of most ball mill installations is presented. This system is simple, inexpensive, and provides the major economic benefits available from contemporary automatic control technology.Value Analysis of Grinding OperationsValue analysis (or engineering, or management), originally developed by Lawrence D. Miles of the General Electric Company (1), focuses on the identification of value (product or process worth versus cost) and provides a systematic procedure for its improvement. A recent research and development project involving the application of the principles of value engineering to grinding operations has provided a basic technoeconomic model of grinding processes (2). The functional objectives of the ball milling process and the means to achieve value based grinding circuit control originate from this study.The Need for Grinding Circuit ControlThe economic effectiveness of a process is determined by the quality or value of the product and the related processing costs. If the inputs (both the raw feed and the applied processing work) are absolutely constant, the product characteristics and the process efficiency will be determined only by the engineering design. The need for and degree of process control is therefore determined by the nature of variations or upsets in the process inputs, and the extent to which these effect product value and operating costs."

Jan 1, 1988

By Jennifer Pell

Dunsmuir Ventures? Nanuq diamond project is located approximately 250 km northeast of Baker Lake and 170 km north of Chesterfield Inlet. It occurs at the intersection of the Wager Bay shear zone with the Keewatin Arch, a major long-lived crustal uplift. The newly discovered diamondiferous kimberlites at Rankin Inlet, Repulse Bay and on Melville Peninsula also occur along this arch. Kimberlite indicator mineral (KIM) sampling has outlined a distinct KIM train more than 35 km long and 6 km wide. Geomorphological studies, boulder displacements and dispersion of magnetite in tills suggest that glacial transport distances were on the order of 4 to 6 kms only. The presence of multiple sources within the main Nanuq indicator train would account for its length and breadth. A second train has been located on the west central part of the property and anomalous concentrations of KIM occur elsewhere. Pyrope garnets (G9?s and G10?s), diamond inclusion field (DI) eclogitic garnets and DI chromites were confirmed by microprobe analyses. Clinopyroxene thermobarometry indicates a cool geotherm, approximately 35 mW/m2, and that mantle within the diamond stability field was tapped. An aeromagnetic survey has identified a number of anomalies. Those with down ice KIM support will have ground geophysical follow-up and will be tested in a spring 2004 drill program. Dunsmuir is optimistic that this will lead to the discovery of a new kimberlite cluster on the Nanuq property.

May 1, 2004

? Founded In 1953 ? Mining growth of 83% since 2007 ? We produced over 1 million ounces of Au in 2012 ? We Forecast of 20% Au production in 2013-2015 ? We have paid a dividend 31 years consecutively. Terry Reid ? 1992-93 Electrical Technical, College ? 1994-95 On the job placement College ? 1998 ? Licensed Millwright, ? 2005-12 ? Maintenance Reliability Planner ? 2012- Present Business Process Owner

Aug 1, 2013

By O. Rabeau, M. Legault, A. Cheilletz, L. Z. Cheng, J. J. Royer, M. Jébrak

"By compiling geological, structural, geophysical, and geochemical information into a 3D geological model, we evaluated the orogenic gold potential in the vicinity of a hidden segment of an important Archean fault zone, the Cadillac-Larder Lake fault (CLLF) in the region of Rouyn-Noranda. The segment of CLLF in the present study is partly covered by Proterozoic sedimentary rocks. Because more than 2000 t Au have been extracted along the CLLF to date, our objective is to evaluate the gold potential at depth along a poorly known segment of this fault. A 3D geological model (50 km × 9 km × 1.5 km) including the covered segment was built through the compilation and homogenization of available geological data and the construction of 23 cross sections. The geology under the Proterozoic cover was evaluated using geophysical inversions, drill holes (42 in total), and surrounding geology. All available assays were filtered and upscaled to a 250 m × 250 m × 250 m regular cell grid to determine and quantify spatial relationships between geological features and mineralized occurrences using the weights of evidence method. Structural features, such as E-W-trending faults and fault intersections, and certain lithologies with a high primary porosity such as volcanoclastic rocks of the Blake River Group and Timiskaming sedimentary rocks, proved to be very prospective, yielding favourable factors with a weight of evidence index W+ > 0.24. These salient features were then assigned a combination index for ultimately evaluating the orogenic gold potential under the sedimentary cover. The zones resulting in an optimization of exploration targeting were attributed the highest probability, representing ~1% of the initial volume. La compilation des données géologiques, géophysiques, structurales, et géochimiques et leur intégration au sein d’un modèle géologique 3D a permis d’évaluer le potentiel aurifère dans les environs d’une importante zone de faille archéenne sous couverture protérozoïque. Cette méthodologie a été développée en utilisant le cas de la Faille Cadillac-Larder Lake (FCLL) dans la région de Rouyn-Noranda. Puisque plus de 2000 t d’Or ont été extrait à proximité de la FCLL, l’objectifs des travaux est l’évaluation du potentiel aurifère en profondeur de ce segment. Un modèle géologique 3D (50 km × 9 km × 1.5 km) incluant le segment sous couverture de la FCLL a été construit en utilisant l’ensemble des données géologiques disponibles et 23 coupes géologiques. La géologie du socle archéen sous la couverture protérozoïque a été interprétée avec des inversions géophysiques, des forages (42 au total) et les contacts géologiques exposés. Les teneurs aurifères dans le secteur ont été filtrées et ajusté à une grille régulière de 250 m × 250 m × 250 m afin d’évaluer et de quantifier les relations spatiales existantes entre certaines entités géologiques et les emplacements minéralisés en utilisant la méthode du poids de la preuve. Les failles de direction Est-Ouest, les intersections de failles ainsi que certaines lithologies possédant une porosité primaire importantes comme les certains tuf du Groupe de Blake River et les sédiments du Timiskaming se sont montrés très prospectifs avec des valeurs de W+ > 0.24. Ces entités géologiques ont ensuite été utilisées par le biais d’un indice de combinaison pour évaluer le potentiel en or de type orogénique sous le couvert sédimentaire. Cette méthodologie permet une optimisation des campagnes d’exploration puisque les zones pour lesquelles la probabilité de minéralisations a été évaluée à la plus haute valeur représentent 1% du volume initial."

Jan 1, 2009

By G. Belzil, F. Robichaud, M. Fullam

"The Goldex mining and milling complex is operated by Agnico-Eagle Mines Ltd. and is located in the Abitibi greenstone belt of Northwest Quebec, Canada. The mill operates presently at a throughput of 8,250 tpd with gold grade varying between 1.8 and 2.2 g/t. The ore is very high in gravity recoverable gold (GRG) at about 92% and as such a significant emphasis was placed on the gravity circuit. Commercial production started in 2008. Average gold recovery is 93.5% with about 68% of gold recovery coming from the gravity circuit. Over the course of the first several years of production, several gravity audits were carried out. In 2009, a complete gravity audit was completed, including ore, classification, Knelson Concentrators, and the gold room. In 2011, an audit was undertaken of the flotation circuit to determine the efficiency by which GRG is floated. Large samples of flotation feed and tails were collected and process for GRG content. This allowed a link between gravity and overall recovery to be made. This paper presents results of the audits and the development of a model linking gravity and overall gold"

Jan 1, 2012