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By Catharine E. G. Farrow, David H. Watkinson

The Ni-rich Epidote Zone of the Fraser Mine at Sudbury is characterized by alteration assemblages rich in epidote, actinolite and magnetite which are roughly concentrically zoned and up to hundreds of meters in length. These zones form discrete areas within the igneous Footwall Breccia below the Sudbury Igneous Complex. The assemblages grade from epidotized Footwall Breccia matrix,through actinolite-bearing rocks with few vestiges of original Footwall Breccia textures, into the most intensely altered rock, a magnetite-rich facies. Pentlandite, pyrrhotite and pyrite are the dominant sulfdeminerals; chalcopyrite is minor. The strongest geochemical differences compared to original Footwall Breccia occur where epidote and actinolite dominate the alteration assemblage (EPDZact facies). The most intense alteration facies are typifed by low Cu/(Cu+Ni) values of <0.1. Strong positive correlations exist between Ni and Co, Cu and Au, and among Ir, Os, Ru and Rh. Chondrite-normalized Ni - PGE -Au - Cu plots display an overall increase in all elements from the least to the most intensely altered facies except for Au and Cu. As the proportion of actinolite increases in the EPDZact facies, the chondrite-normalized profles fatten considerably due to low Au and Cu contents. Abundances of Ni, Ir, Ru and Rhalmost ubiquitously increase with degree of alteration. In contrast, Cu, Zn, Ag and Au contents are low in almost all facies. It is suggested that saline hydrothermal fluids moved through the Epidote Zone formation and became more oxidized as they reacted with the Footwall Breccia and with footwall units, including ultramafic rocks. As this trend continued, magnetite-rich zones eventually developed. The occurrence of calcite locally in these magnetite-rich zones suggests that the pH of the fluid increased, causing Cu solubility to drop as activity in the hydrothermal system waned. Sudden changes in fluid composition such as this may have been due to an influx of fluid from bounding ultramafic rocks. Hydrothermal activity was focused along the margins of footwall ultramafic units. Individual hydrother-mal cells may have formed in the Footwall Breccia along pre-existing structures or sulfde concentrations. Metals may have been scavenged from sulfide-bearing Footwall Breccia and possibly Sublayer rocks. Nickel and some PGE were deposited in the Epidote Zone, whereas Cu, Au and Ag continued out-ward into the footwall where they were deposited as Cu-rich footwall veins. Copyright © 1996 Canadian Institute of Mining, Metallurgy and Petroleum.

Jan 1, 1996

By Catharine E. G. Farrow, David H. Watkinson

Abstract-The Ni-rich Epidote Zone of the Fraser Mine at Sudbury is characterized by alteration assemblages rich in epidote, actinolite and magnetite which are roughly concentrically zoned and up to hundreds of meters in length. These zones form discrete areas within the igneous Footwall Breccia below the Sudbury Igneous Complex. The assemblages grade from epidotized Footwall Breccia matrix, through actinolite-bearing rocks with few vestiges of original Footwall Breccia textures, into the most intensely altered rock, a magnetite-rich facies. Pentlandite, pyrrhotite and pyrite are the dominant sulfide minerals; chalcopyrite is minor. The strongest geochemical differences compared to original Footwall Breccia occur where epidote and actinolite dominate the alteration assemblage (EPDZact facies). The most intense alteration facies are typified by low Cu/(Cu+Ni) values of <0.1. Strong positive correlations exist between Ni and Co, Cu and Au, and among Ir, Os, Ru and Rh. Chondrite-normalized Ni - PGE - Au - Cu plots display an overall increase in all elements from the least to the most intensely altered facies except for Au and Cu. As the proportion of actinolite increases in the EPDZact facies, the chondrite-normalized profiles flatten considerably due to low Au and Cu contents. Abundances of Ni, Ir, Ru and Rh almost ubiquitously increase with degree of alteration. In contrast, Cu, Zn, Ag and Au contents are low in almost all facies. It is suggested that saline hydrothermal fluids moved through the Epidote Zone formation and became more oxidized as they reacted with the Footwall Breccia and with footwall units, including ultramafic rocks. As this trend continued, magnetite-rich zones eventually developed. The occurrence of calcite locally in these magnetite-rich zones suggests that the pH of the fluid increased, causing Cu solubility to drop as activity in the hydrothermal system waned. Sudden changes in fluid composition such as this may have been due to an influx of fluid from bounding ultramafic rocks. Hydrothermal activity was focused along the margins of footwall ultramafic units. Individual hydrothermal cells may have formed in the Footwall Breccia along pre-existing structures or sulfide concentrations. Metals may have been scavenged from sulfide-bearing Footwall Breccia and possibly Sublayer rocks. Nickel and some PGE were deposited in the Epidote Zone, whereas Cu, Au and Ag continued outward into the footwall where they were deposited as Cu-rich footwall veins.

Jan 1, 1996

By N. Katsikaros, A. Lewis-Gray, P. Richards

"To optimize gold recovery in complex leach-to-electrowinning processes, Gekko Systems developed the Gekko resin exchange column (G-REX) as an intermediate step, using a highly gold-selective resin to isolate contaminant metals. The AuRIX®100 resin produced by Purolite is licensed exclusively to Gekko, with the G-REX column designed specifically for this resin. Operational experience has been gained at the Castlemaine Goldfields Ballarat gold mine. In near-continuous operation since 2008, the Ballarat plant treats unclarified concentrate leach solution. The extension of this technology to higher throughputs and more complex chemistry is discussed.RÉSUMÉ Afin d’optimiser la récupération de l’or dans des procédés complexes impliquant la lixiviation suivie de l’extraction électrolytique, Gekko Systems a développé la colonne Gekko de résines échangeuses d’ions (G-REX) comme étape intermédiaire, à l’aide d’une résine hautement sélective pour la récupération de l’or qui permet d’isoler les métaux contaminants. Gekko détient la licence exclusive pour la résine AuRIX®100 produite par Purolite, et la colonne G-REX a été spécifiquement conçue pour cette résine. C’est à la mine d’or Ballarat de Castlemaine Goldfields que l’expérience opérationnelle a été acquise. L’usine de Ballarat, en exploitation quasi-continue depuis 2008, traite une solution concentrée non clarifiée de lixiviation. L’extension de cette technologie à des capacités supérieures et à une chimie plus complexe est examinée."

Jan 1, 2017

By J. H. Shillabeer

"Rational exploration requires the prior selection of areas possessing excellent geological potential and minimum hazards to commercial development . Within an over-all strategy of grass-roots exploration, two procedures for selecting areas for (i) coal and (ii) metals exploration are described. The procedures explicitly balance infrastructure requirements and environmental concerns for areas of geological merit not alienated in parks and reserves. Through consensus, priorities are attached to those areas meriting closer scrutiny and field reconnaissance.IntroductionMining companies need to know that having made a potentially economic discovery, they will be allowed to develop it with minimum delay and at reasonable cost. The environment for exploration in British Columbia is complex and recent experience suggests that conditions are not becoming any easier. Conflicts over land use issues, preservation and economic development are common. The high cost of exploration requires that the risks should be offset where possible by: (i) carefully selecting the areas in which to work (ii) conducting operations in a responsible manner, and (iii) working cooperatively with the community of interests. This paper concerns the first action: prior selection of areas.To aid exploration planning at Suncor, a procedure was developed to grade those areas of the province possessing favourable geology according to the ease with which a mine might be developed . This had to be done within the constraints of the company&apos;s over-all approach to exploration. This emphasizes ""grass-roots"" exploration of self-generated projects in British Columbia. In addition, having selected a favourable belt of rocks, it is intended to persevere there while steadily adding to the accumulated data base and local experience. Hence, it is intended to concentrate on an area. This implies a long-term commitment to an area which in turn increases the importance of the original selection.Suncor&apos;s search is directed to finding base and precious metals in intrusive and volcanic environments, and export quality coal."

Jan 1, 1985

By G. Bylapudi, K. Mondal, J. Hirschi

ABSTRACT: Rock bolts are the main form of defence against rock falls in mines. Conditions under-ground are conducive to corrosion. A perception exists about American coal mines that bolt corrosion is not an issue, especially when bolts are fully grouted. This perception is not necessarily accurate due to the formation of micro-cracks as the resin sets and to subsequent rock movement that breaks the resin column’s continuity. Corrosion should be considered when designing rock bolt support in long-term excavations. This paper explores the problem of corrosion, outlines a method to determine the corrosion potential of bolts, and suggests ways to mitigate such effects.

Jan 1, 2010

By T. Vovan, A. Galibois, M. Fiset

"In order to establish some links between the 22 specimens found on the site of Les Forges du St. Maurice, their slag inclusions have been analyzed by electron microprobe. Comparison between their contents of various specific oxides allowed us to segregate them into two major groups and even to isolate two sub-groups possibly characterized by some equilibrium between their oxides and/or the type of ores used.In all probability, limes/one coupled systematically with a soil rich in hydrated aluminum silicates was used as a flux.Based upon the existence of a pseudo equilibrium between the slag and the metal, the elaboration of the bulk of the specimens can be ascribed to the indirect rather than the direct method whereas the process temperature can be estimated at at least /400°C.RESUMEDans le but d&apos;etablir des liens entre les 22 objects provenant des Forges du St-Maurice, leurs inclusions de scories ont été analysées par microsonde. La comparison des teneurs en divers oxydes a permis de les séparer en deux groupes majeurs et même d&apos;y distinguer deux sous-groupes pouvant être reliés à la forme d&apos;équilibre entre certains oxydes et/ou au type de minerai utilisé. Selon toute vraisemblance, le fondant utilisé était de la pierre à chaux à laquelle on ajoutait systématiquement une terre riche en silicates hydratés d &apos;aluminium.Des considérations sur l&apos;existence d&apos;un certain équilibre entre les scories ei le métallaisset croire que la plupart des objets ont été élaborés plutôt par la méthode indirecte que directe et que la température d&apos;élaboration se situait à au maint 1400°C."

Jan 1, 1984

By B. R. Neufeld, M. G. Heximer, S. J. Roach, W. G. Van Luven, D. G. Reynolds

"Teck Metals Ltd. operates an integrated zinc-lead complex at Trail, British Columbia, Canada. In the zinc plant, zinc concentrates are roasted to produce calcine, which is then processed in the leaching circuit for zinc recovery. Calcine is first dissolved at pH <2.0. This is followed by a precipitation stage using additional calcine that removes iron as a ferric hydroxide precipitate which is recycled to the lead operations. It is during this pH adjustment that impurities, notably arsenic, antimony and germanium, are co-precipitated with ferric hydroxide which is the primary removal phase for these elements. Recent processing conditions have resulted in lower iron inputs to the leaching circuit and this has resulted in insufficient co-precipitation of key impurities. This paper summarizes the influence of iron concentrations on impurity removal using laboratory and plant scale surveys, and emphasizes key specification limits for the primary iron removal circuit.INTRODUCTIONThe Sulphide Leach Plant (SLP) at Teck Metals Ltd., Trail Operations produces a zinc sulphate electrolyte from three different zinc bearing streams:1. Calcine, primarily containing zinc oxide, from the roasters2. Zinc electrolyte from the Oxide Leach Plant (OLP) is produced by leaching zinc oxide fume from the pyrometallurgical lead smelting operations3. Zinc slurry from the Zinc Pressure Leach (ZPL) autoclaveThe feed sources are blended and introduced to the iron removal process to precipitate iron in the form of a hydrolyzed iron precipitate which is recycled to the lead smelting operation. Along with iron, impurities, namely arsenic, antimony, germanium and silica, also co-precipitate; this process acts as the primary removal step for these elements. Following iron removal, the electrolyte is further processed in the zinc dust purification circuits. Cadmium and copper are removed in the cold stage circuit via zinc dust cementation, followed by cobalt cementation in the hot stage circuit."

Jan 1, 2016

By T. E. W. Nind

"A short description of the chamber lift method for producing oil wells is followed by some comments on compressor requirements and gas utilization. A quantitative analysis of the process is presented and, based on this analysis, criteria are suggested for selecting wells for which this type of lift might be suitable. The analysis leads to the conclusions that chamber lift is an efficient producing mechanism for wells having very low productivity indices (say about 0.05 bbl/d/ p.s.i. or less), but that for such wells optimum utilization of injection gas cannot be attained. It is suggested that the gas injection time per cycle should be kept as low as possible, compatible with a small oil fallback volume, and that the cycle frequency should be in the range of 20-40 cycles/ day. For wells with productivity indices of 0.2 bbl/d/p.s.i. or higher, chamber lift is relatively inefficient; how-ever, if well allowables are low it may offer an attractive, low cost, alternative to gas lift or pumping."

Jan 1, 1960

By Daniel Hodouin, Robert Lanthier, Yve Dube

"A procedure f or constructing a grinding mill dynamic model is proposed. This model is used in a dynamic simulator of are grinding circuits. The simulator is designed for flexible flow sheets involving different grinding mills and particle classifiers and is able to accept several single variable PID control loops. The dynamic model is validated on a laboratory ball mill, and calibrated to an industrial installation. The simulator is used for characterization of grinding circuit dynamic behaviour and tuning of control strategiesIntroductionThe ore grinding operation is a critical step of the ore preparation process because it is the last comminution stage before the separation of minerals. The properties of the ground minerals to be concentrated, control the quality and efficiency of the separation process. This is why it is important to control properly the operation of the last grinding stage, commonly constituted of a closed circuit ball mill with classifier . To provide an adequate fine product, the grinding operation should compensate for the perturbations of the feed characteristics (size analysis, grindability, etc.). The main objective is to maintain a constant size distribution for providing stable operating conditions to the separation units. Simultaneously another usual objective is to operate the grinding circuit at a maximum capacity.Automatic control applied to grinding circuit s is the appropriate approach to improve its operation. Most frequently average optimal operating conditions are determined from steady -state performances of the circuit , and the automatic control is used for stabilizing the operation at selected values of the process variables . In the traditional approach, one or several single input! single output (SISO) control loops are implemented and empirically tuned. Advanced control practices&apos;!&apos; are based on a quantitative analysis of the circuit dynamics, which could also give a basis for the tuning of conventional SISO 100ps(2)."

Jan 1, 1987

Agenda ?The Context ?The Challenge ?The Solution ?Benefits and lessons learnt from pilots ?Next Steps The Context ?Facilitate management decision making process by supporting the development of value/risk based business cases. ?Large scale investments by extractive industries are expected tobring broad-based benefits to local communities (e.g.: health, education, jobs, infrastructure) ?Investors continue to expect the demonstration of social performance?Specific interventions bring direct value to companies (e.g. skills development) ?Social Investments are key to protecting a company?s license to operate ?Quantifying the value of these investments and planning accordingly, however, has long posed a challenge for the extractive industries and community development practitioners

May 1, 2011

By Kevin Bell

About Beltek Inc. For more than a decade Beltek, Inc. has been working with national and international organizations to harness and deliver solutions which gain real ebusiness advantages in today&apos;s world. Our objectives are to partner with our customers to achieve maximum results, while reducing costs. At Beltek, we provide a commitment to you and your organization&apos;s needs. Whether that be delivered by ensuring our services and products are state of the art or by providing a level of personalized service, which makes you feel like the center of attention, Beltek is about adding value to every job we work on. The individuals who work at Beltek quickly become your friends because we share your passion and enthusiasm for the business we are in. That&apos;s why every person is a leader in his or her respective fields. Having these individuals as apart of our business ensures you get the best out of our equipment, receive the very latest in advise, problem solving and support. We also pride ourselves on our ability to remain flexible at all times because we know deadlines and schedules can change quickly, so we always go the extra mile to deliver exactly what you need.

May 1, 2004

By C. Dodds, R. S. Ferrari-John, The University of Nottingham, G. Dimitrakis, J. Katrib, A. R. Batchelor

"Sorting technologies have the potential to reduce energy use in comminution by rejecting uneconomic ore before feed material enters the mill. However, a major challenge for sorting porphyry copper ores is providing a basis of discrimination between valuable and non-valuable fragments, due to their complex mineralogies and textural features. Microwave heating in combination with infra-red detection (MW-IR) has been shown to provide upgraded feedstock for certain ores at bench scale. Selective heating of copper sulphide minerals compared to the gangue leads to an increased thermal response for valuable fragments, providing the basis for sorting.Rapid scale up of MW-IR from bench scale to a 100 t/h continuous pilot plant facility has been facilitated by the design of microwave choking structures to allow continuous operation at industrially meaningful throughputs, whilst meeting health and safety and electromagnetic compliance standards, and the integration of materials handling with electromagnetic systems.Laboratory batch testing on a pilot scale microwave system has been undertaken to investigate the thermal response of copper ores under industrial conditions, at microwave energy inputs up to 1 kWh/t. These results provided the operating window and recommended test conditions for the continuous pilot plant. Sortability curves predicted in the laboratory are in good agreement with separations achieved during continuous pilot plant operations. The potential microwave sortability of a number of ores has been studied, allowing informed decisions to be made about potential ore candidates based on mineralogy. Future development of the technology will be underpinned by the creation and validation of scale up concepts for 1000 t/h operations. Understanding the value proposition for individual sites/applications will be central to unlocking the potential economic and environmental benefits of microwave sorting."

Jan 1, 2016

By Alex Matheson, Nick W. D. Massey, Peter T. Bobrowsky

Crowing pressures on aggregate resources include diminishing reserves, high transportation costs, sterilization and land use conflicts. In the absence of detailed resource knowledge for a particular region, aggregate resource potential maps provide the best "first approximation" regarding the surficial distribution of sand and gravel. The 1:50 000 scale Level Ill aggregate potential map integrates several important factors which influence the management of sand and gravel. Data used to generate this type of thematic map is readily available in most areas, fieldwork required is minimal, there is a logical quantitative evaluation of the data layers and integration is easily accomplished on a desktop PC-based platform. Also the aggregate potential map, with its focus on identifying areas of potential future aggregate exploitation as well as present inventory, provides a useful tool for the aggregate explorationist.

Jan 1, 2001

RÉSUMÉ Cet article traite d’une analyse technique et économique du concept du triage optique en vue d’améliorer la rentabilité des opérations minières. Le principe du tri optique et les principaux systèmes et modules servant au fonctionnement de l’appareil de triage sont décrits. un modèle a été développé pour analyser l’intérêt économique d’une opération de triage optique. L’étude est basée sur des données provenant d’une halde de minerai à faible teneur en or, déposé à la surface, et de minerai extrait des opérations souterraines courantes de la mine Beaufor au Québec. Les résultats de cette analyse indiquent que l’opération de triage optique permet d’améliorer grandement la performance économique; l’opération devient alors rentable pour des teneurs en or relativement petites.

Jan 1, 2010

By S. Shairp

"After cooling and thickening, slurry from the second stage of the Hudbay zinc pressure leach circuit is filtered and washed on a belt filter prior to disposal. At times, the belt filter can be a bottleneck to the process. Preliminary studies show that filterability of the second-stage (HAL) autoclave leach residue can be indicated by particle size distribution of the filter feed and filtered residue cake. In particular, the Volume Weighted Mean Diameter, D[4,3], generated by a laser diffraction particle size analyzer from samples of HAL Filter feed, shows residues that filter more poorly have a lower Volume Weighted Mean Diameter than those that filter better. INTRODUCTIONHudbay produces cast zinc metal from blends of zinc concentrates at its metallurgical complex in Flin Flon, Manitoba, Canada, using Sherritt’s two-stage pressure leach process (Collins et al., 1994; Collins et al., 1995; Barth et al., 1998; Shairp et al., 2006). Pressure leaching replaced the original roastleach- electrowinning process in 1993.Filtration for the second-stage (HAL) leach residue originally consisted of two stages of vacuum drum filtration with intermediate cake repulping stirred tanks. As part of Hudbay’s 777 Project, with a designed increase in cast zinc production, a pre-feasibility study by SNC-Lavalin Inc. showed that losses of soluble zinc in the zinc pressure leach residue could be reduced by installing more efficient filtering and washing equipment. Based on laboratory performance, capital cost, installation ability, and potential operating cost savings, a 70 m2 Filtres Phillipe belt filter was chosen for the HAL residue, and commissioned in 2000/2001.When the HAL belt filter is performing well, there is no pooling of water on the surface, moisture content is relatively low, and subsequent analysis shows that water soluble zinc content is relatively low. There have been occasions where the filter has performed poorly with respect to the aforementioned parameters. Aside from the filter experiencing mechanical difficulties, there are several variables affecting leach residue filtration:"

Jan 1, 2012

By J. Cayouette, C. Bolduc, P. Blatter

"The LaRonde mill was commissioned in 1988 and began treating ore from the Penna shaft in 2000. The mill has been expanded to accommodate 7,500 t/day, but ramped down to 6,000 t/day since the deep extension began. The process recovers gold, silver, and base metals. In 2008, the Goldex plant began trucking gold-pyrite concentrate to a treatment plant feeding pulp to the LaRonde mill, increasing gold output by 40,000 oz. In 2009, the high-grade Lapa ore processing facilities were annexed to the LaRonde plant, increasing gold output by 120,000 oz. This paper outlines the metallurgical considerations related to the treatment of different ore types.RÉSUMÉ Le concentrateur de la mine LaRonde a été mis en service en 1988 et a commencé à traiter le minerai du puits Penna en 2000. La capacité du concentrateur a augmenté afin de permettre le traitement de 7 500 tonnes de minerai par jour, capacité qui est retombée à 6 000 tonnes par jour (tpj) depuis le début de l’extension en profondeur de la mine. Ce procédé permet de récupérer de l’or, de l’argent et des métaux communs. En 2008, l’usine de traitement Goldex a commencé à transporter par camion du concentré de pyrite et d’or vers une usine de traitement alimentant en pulpe le concentrateur de LaRonde, augmentant ainsi la production d’or de 40 000 onces. En 2009, les installations de traitement du minerai à haute teneur de Lapa ont été annexées à l’usine de traitement de LaRonde, augmentant la production d’or de 120 000 onces. Cet article passe en revue les considérations métallurgiques liées au traitement de différents types de minerai."

Jan 1, 2017

By T. E. Wakefield

"Final Galloway (stage) designs for vertical drill and blast shaft sinking projects evolve from complex thought patterns which integrate operational processes, systems and methods of communication, power supply, drilling, blasting, ventilating, mucking, supporting, surveying, dewatering, sealing, concrete lining and shaft furnishing. Attention to ergonomic design detail at the shaftsman / structure interface is at the heart of safe and successful multi-deck working platforms. For economy the end product must have a low mass to reduce suspension rope end loads to be able to use smaller suspension hoists and have lighter headframe structures, be robust to withstand concussion damage, be easily constructible on site, be maintainable in the shaft barrel, and comply with safety and legislated standards. This paper’s ambition is to describe a systematic design framework and sequenced thought process that delivers a product that is engineered with excellence, illustrated by making use of two designs that evolved during recent Galloway projects, one destined for a large diameter man/material shaft, the other for a ventilation shaft. The stage engineering iterative process starts with mapping permanent and sinking hoisting layouts, followed by laying out horizontal deck plans, mostly constrained by the permanent shaft purpose and configuration, whilst maximizing openings to enable muck to be removed rapidly for the best sinking cycles. Concurrently the designer needs to understand the chosen sinking methodologies in conjunction with crewing to determine the number of decks and fix their spacing. Insufficient access to move and line up formwork, set reinforcing rods and pour concrete in the confined spaces of the stage is an inherent major risk to be mitigated. An iterative and integrative process follows for the primary configuration which delves into increasing design detail, accommodating all other methodology influences, resulting in 3D layouts for further risk assessment, review and fine tuning by seasoned shaftsmen. INTRODUCTION Documented colliery shaft sinking practice from the late 1800’s makes reference to purpose built walling (bricked lining) cribs with floors suspended in sinking shafts, thereby allowing shaft lining to proceed concurrently with the excavation. Improvements were made by Sir William Galloway who introduced two decks supported at the corners by angle irons. The sinking stage, or Galloway, has developed substantially over time to be the in-barrel heart of the sinking operation, with overwhelming complexity for those who have to design one for the first time."

Jan 1, 2019

?Four-wheel, skid-steer, rover developed for CSA ?U-chassis for payload accommodation ?Passive geometric suspension ?Max speed 13km/hr ?Remote workstation ?275kg payload capacity ?On-board processor, IMU, motor encoders ?5.2kW-h battery capacity

May 1, 2013

By J. B. Sabey, V. R. Degner, D. MacGillivray

"Hydrodynamics principals are applied to the design of a natural air ingestion flotation machine for coarse solids applications. Preliminary laboratory test data and subsequent operating plant flotation kinetic performance evaluations are reviewed. INTRODUCTIONThe concentration of potash (sylvite, KCI) from halite and other salts using flotation is well understood and practice a with much success. Reagent schemes and plant circuitry for obtaining the desired product recovery and grade have been established with proven performance. These flotation circuits normally process the medium and finer size particles, less than 30 mesh (600 microns).However, often the potash market trends specifically demand a coarse product size. This emphasis, accompanied by the existing high losses of coarse (+30 mesh) potash in flotation circuits, creates the need for development of a flotation machines specifically designed for coarse potash beneficiation.This technical challenge was undertaken by the WEMCO Research and Development Group. The specific objectives of this flotation machine development program were ( l) to achieve an ""Ultra Coarse Flotation Machine"" capable of adequately suspending and transporting particles in the 4 - 30 mesh (4.75 - 0.6 mm) size range at solids concentrations of 30% or greater and (2) ascertain metallurgical performance of this machine.This paper covers the development (both theoretical and mechanical/ hydrodynamic), the field test program and results, a discussion of applicable flotation kinetics, and conclusions of this ""Coarse Potash Flotation Machine"" development project."

Jan 1, 1986

By Pierre Antoine Dhaiti, Gilbert Sergerie, Michel Dagbert, Jean-Maurice Brodeur

"Quality of iron ore is generally determined by several factors which can be correlated or independent. Among these f actors, we generally find per cent iron, silica, magnetite or hardness. Forecasting the short- and long-term fluctuations of these f actors in the future pit is an important feature of mine planning in these deposits. Computer simulation provides a realistic answer to these questions. It allows to generate values for the most important quality features of each shovel load with the proper correlations between them as well as between one load and the next being fully reproduced. Then different sampling schemes f or grade control or blending facilities can be examined on the simulated data. The mechanics of the simulation procedure and its potential applications are described in an example.IntroductionThe purpose of this paper is to illustrate the use of in-situ grade simulation in the planning o f the grade control in an iron ore min e. More precisely, given a production unit of given size, we need to know how many samples have to be collected in that unit so that we ca n recognize its grade with a reasonable precision. Conclusions that we would like to arrive at are of the type: with 4 blasthole samples we ca n get the iron grade of a 10,000 ton bloc k with less than a ± 2% Fe error 95% of the time.The approach t hat we take to solve this problem is simulation. We simulate the grade of samples and the grade of the block that contains these samples. We repeat the simulation for hundred s o f blocks. By comparing the sample grade with the block grade in each case, we determine the actual number o f blocks where the difference sample-bloc k is less than a given limit."

Jan 1, 1983