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By P. P. Sinha, D. N. Bhatia, B. R. Ghosh, R. K. Gupta

Medium carbon, low alloy, high-strength steels containing Ni, Cr, and Mo are used for the fabrication of various types of high-strength fasteners required for launch vehicle structures. Cold heading properties and response to hardening and tempering are the essential requirements of the material for fabrication and application, respectively. Combining these two requirements is essentially warranted in high-strength fastener-grade steels. Cold heading properties require ductility, which can be achieved through spheroidizing treatments. In the absence of a suitable spheroidizing cycle for medium carbon 3.8 Ni, 1.8 Cr, 0.3 Mo steel, experiments were carried out with a theoretical understanding of the alloy system. This paper presents the experiments and results obtained after a spheroidizing treatment, which was carried out to optimize the process. Hardness measurements were carried out and microstructural studies were conducted to assess the spheroidization process and to determine the optimal spheroidization parameters.

Jan 1, 2007

By Salvador Gómez, Rodolfo Espinosa, Jaime Bravo, Leopoldo Gallas

"Compañia Fresnillo, S.A. de C.V. - Proaño Mine, is owned by Industrias Peñoles S.A. de C.V. (Peñoles). The Proaño Mine, is one of the richest silver underground mines in the World, and for this reason, production capacity has always being expanded, based on generated reserves. Reserve generation has not being an easy task as this is a vein type deposit.This paper presents the growing stages at the Concentrator, for about the last twenty years; which can be listed as follows:1.,Increase in capacity from 1,000 to 4,500 tonnes per day, at several stages; on the same infrastructure, and without production interruptions.2.,Addition of a new flotation circuit to recover a zinc concentrate with a high silver content.3.,Installation of a semi-autogenous (SAG) mill, to replace a conventional crushing circuit. 4.,Modernization. Installation of an on stream analyser, an automatic reagent dosification system, 4500 ft3 unit cells, pressure filtration, a closed circuit video system to help process monitoring, an automatic ball addition system for SAG and ball mills, and on-line particle size analysers.5.,Silver recovery from old tailings, installing a 2,350 tonne per day treatment plant.INTRODUCTIONIndustrias Peñoles, S.A. de C.V. (Peñoles)Peñoles’ mission is to add sustainable value to non-renewable natural resources. Peñoles seeks to: build long-term shareholder value; provide customers with the highest quality product services; maintain productive long-term relationship with suppliers; develop and promote the capabilities of their personnel; foster mutually beneficial relationship with the communities in which operates; protect and preserve the environment."

Jan 1, 2002

By John Lindsay

"Although diamond mining is a relative newcomer to the Canadian mining industry, with the first diamond mine coming on stream in 1998, Canada is already a significant producer of high quality diamonds. This paper will review diamond production trends and highlight some of the projects currently under development, which have the potential to enhance Canada’s role as a significant diamond producer.Diamond recovery plants generally incorporate well-established mineral processing and recovery techniques, with issues such as product security, cut-off sizes, and diamond preservation becoming important considerations when developing process flowsheets. A diamond processing plant must achieve three key objectives, namely:• Liberation of the diamonds from the host rock;• Separation of the heavy minerals, which include the diamonds, from the host rock;• Recovery of the diamonds from the heavy mineral concentrates.Processing technologies and equipment commonly utilized in diamond processing plants will be reviewed and some of the significant issues associated with each option briefly discussed.Typical process flowsheets will be presented.Finally, an overview of De Beers’ Victor diamond project, located in northern Ontario, will be provided. This potentially significant diamond producer is currently at a pre-feasibility stage of development.DIAMONDS IN CANADAWorld Diamond ProductionCommercial diamond mining commenced in earnest with the discovery of the Kimberley diamondfields in South Africa in the late 1800s, and this resulted in a dramatic increase in the supply of diamonds. As can be seen from figure 1, world diamond production, mainly from South Africa, Angola, Congo, and Namibia, remained relatively constant through the early 1900s until the development of the large Russian kimberlite pipes in the 1950s. Production increased again in the 1960s and 70s with the development of the Botswana mines, but the most significant increase in global production came from the Argyle mine in Australia, which came on stream in 1983 and produced a peak of almost 43 million carats in 1994, representing approximately 40% of the world market. Production from Argyle has since fallen-off as grades have declined and the strip ratio has increased with the deepening of the open pit."

Jan 1, 2003

By Tony Robles

"A new process is disclosed for the recovery of gold and/or silver values from activated carbon wherein they are adsorbed as cyanide complexes. A unique chemistry allows the new process to use mill process water containing an inexpensive, non-hazardous compound as the eluant. The new process has an elution period of 5 hours at 98°C. The gold in the eluant can be recovered by electrowinning or zinc precipitation. The new elution process is simple, reliable, and provides an eluted carbon that may not require thermal regeneration before reuse. Retrofitting the new process to existing processes such as Zadra, Anglo, and others will not require significant capital expenditures.IntroductionThe efficient and reliable elution process for gold/silver from activated carbon is a very important process in the gold mining industry. The most common techniques for elution of gold cyanide from activated carbon are the Zadra and Anglo procedures.Specialized elution techniques like the Micron and Acetonitrile processes have not been commercialized to significant extent probably due to relatively complex unit operations and expensive reagents.Important functions of the gold recovery circuit are:Efficiently recover gold/silver from the loaded carbon.Carbon is in good condition for reuse for optimum recovery.The pregnant solution is amenable to electrowinning or zinc precipitation to recover gold/silver from the solution.The whole process to be simple and short to reduce gold inventories.Present Elution ProcessesTable 1 shows some carbon elution processes that are available today. The two main elution processes used in the industry are: (1) the Zadra process, in which hot cyanide solution is circulated through an elution column and electrowinning cells; and (2) the Anglo American Research Laboratory (Anglo) process, consisting of a pretreatment step with caustic cyanide solution, followed by elution with deionized water."

Jan 1, 2000

By Kallioinen Jouko

"Advanced Flotation Technology is the application driven design of Don-Oliver flotation cells to achieve the optimum performance for each type and grind of flotation. Optimum performance is the combination of both recovery and selectivity.Optimized performance is the combined product of optimized mixing and effective froth removal. Optimized mixing is applied to roughers, scavengers, cleaners and specialty cells such as those to float hydrocyclone underflows in both primary and regrind circuits in order to reduce overgrinding. Effective mixing for fine material is easy, but overmixing reduces selectivity in frothbed.Selectivity in flotation is an important target, especially when treating complex ores, and parameters in frothbed have been examined to improve the separation of minerals and eliminate circumstances that reduce separation rate.Advances in process control have been achieved with expert controls and instructive operator information data. This has gained a higher degree of understanding of cell operation and ore type being processed to be used in future process development work. Excellent results of this Advanced Flotation Technology have been achieved and designs through 7000 cu ft (200 m3) are currently available for high capacity concentrators. This paper will detail how flotation cells are more responsive to the exact requirements of the duty specified."

Jan 1, 2000

By E. C. Morton

The Western Australian School of Mines (WASM) has developed a facility for the static testing of large scale ground support elements. The samples are loaded using a mechanical screw feed jack. Instruments measure the displacement and the load being applied. Methods have been developed for testing of mesh, shotcrete and membranes. Mesh samples are restrained on all sides and loaded centrally. A new large scale punch test method has been developed to evaluate shotcrete and membranes. These products are sprayed on to a sandstone substrate containing a centrally located isolated disc. The sprayed product is loaded by displacing the disk. The different test methods are described in detail. The test program involved two types of mesh, several shotcrete mix designs with different curing times and one membrane product. The force-displacement responses are used to directly compare the products. The implications for implementation of the different ground support products are discussed.

May 1, 2009

? CONSTRUCTION AND MINING COSTS ARE HIGH IN THE ARCTIC ? VERTICAL KIMBERLITE PIPES WITH HIGH STRIP RATIOS ? SITE SPECIFIC GEOMETRIC CONSTRAINTS ? OPEN PIT FOLLOWED BY UNDERGROUND MINING ? HIGH KIMBERLITE UNIT COSTS TRACK INSTALLED ON PIT WALL ? INTENDED TO REPLACE MAIN HAUL RAMP ? 5 MIN HOIST CYCLE TIME ? KEY ADVANTAGES - REDUCED CYCLE AND STRIPPING RATIO ? TECHNOLOGY EXISTS IN OTHER APPLICATIONS

May 1, 2003

By M. C. Bétournay

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

May 1, 2005

Leadership "Organizing a group of people to achieve a common goal" Paradigms ? Rush to produce or cut costs. ? The most important thing after safety is production. ? We?ll take care of ??this?? once in production. ? I know what to do, 30 years of experience in mining. ? I want a 100% reliable operation.

Aug 1, 2013

By G. Bonnell, W. Lidkea, M. C. Bétournay, E. Edwardson

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

Jan 1, 2005

By R. Clarkson

"The Yukon's numerous (185) placer gold mines are still a major social and economic force in this developing economy. Gold recovery at each of the various sluiceboxes is not optimized due to extremely difficult sampling logistics and a shortage of technical expertise and industrial research.At each of six operating placer mines, numerous sluicebox tailings samples were collected with hand held sample cutters and combined into large (2-7 cubic yards) duplicate samples. The entire sample volumes were screened and processed on a shaking table to determine gold losses. The existing and potential gold recoveries and recommended sluicebox design and operating parameters are presented.2 ACKNOWLEDGMENTSThe Project Manager gratefully acknowledges the following support for this placer research program:The funding received from the National Research Council's Industrial Research Program, the Canada/Yukon Economic Development Agreement and the Canada Center for Minerals and Energy Technology (CANMET): andThe technical advice provided by Tad Cienski (CANMET), Ron Johnson (KPMA), George Poling (University of B.C.) and Dan Walsh (University of Alaska).3 OBJECTIVESThe objectives of the Gold Recovery Project are to: evaluate gold losses with statistically based sampling programs; determine how to improve gold recovery; assist miners with the recommended technology and make this information available to the entire placer industry."

Jan 1, 1990

By Mark McComb, Geoffrey R. Lane

"Over the years many differing approaches have been developed to clearly understand the nature, mode of occurrence, associations and deportment of both free-milling and refractory gold in a wide variety of differing geologic environments and plant products. Many approaches can be taken to characterize the ore which may occur as complex fine grained gold, ultra-fine grained gold, coarse nuggetty gold, complex Asrich refractory gold and double-refractory gold. The approach taken in assessing small drill core composites from Novo Resources Beaton Creek Paleoplacer gold project located in the Pilbara region of Australia was complicated by the nature of the ore, the small amount of sample available from current exploration work, and the gold grade and the grain size distribution. In this case the scope of the study was limited by sample availability although significant amounts of valuable information was also gained. This gold characterization study included the following elements:??Size fraction assays??Ore microscopy??Preparation of heavy mineral concentrates from sized fractions (screening) of crushed or milled head using heavy liquids and Superpan table.??Systematic scans of the heavy mineral concentrate, middling, and tailing fractions using TIMA Automated Scanning Electron Microscopy integrated with an Energy Dispersive Spectrometry to provide semi-quantitative elemental analysis of the individual grains found in the sample.The unique methodology employed to detail the gold deportment was the combination of the Tescan Integrated Mineral Analyser (TIMA) and the Oxford INCA GSR software. This technique not only allowed us to document the deportment of gold but recognize other associated minerals, which included gersdorffite, chalcopyrite, uraninite, coffinite, brannerite and several Rare Earth-bearing minerals.INTRODUCTIONGold deportment studies are commonly carried out on preliminary gold exploration projects in order to determine the various limitations, which may effect processing of the potential ore. This is often because it may be expected that there may be a refractory component to the gold, which may limit physical separation techniques and suggest more costly hydrometallurgical techniques. Often when carrying out gold deportment studies the mineralogical methods may be limited to assuming that the gold will be fine and easily found using standard techniques of optical microscopy or Scanning Electron Microscopy. This may not always be the case as various geological environments may pose their own individual problems to determining the deportment of the gold grains."

Jan 1, 2015

By G. R. Dunning, M. R. Wilson

"Abstract - The early Paleozoic accretionary tectonic regime that was established along the Laurentian margin of the Newfoundland Appalachians provided a favorable setting for shear-hosted gold mineralization along a major terrane suture, the Baie Verte-Brompton Line. The Stog’er Tight prospect is one of several mesothermal-style gold occurrences hosted by shear zones within accreted ophiolites and oceanic arc terranes on the Baie Verte Peninsula. It is an epigenetic, stratabound deposit that is confined to shallow-level gabbro sills within the volcanic cover sequence of the allochthonous Point Rousse ophiolite complex. Gold mineralization at Stog’er Tight is associated with hydrothermal mineral assemblages represented by chlorite-calcite, sericite-ankerite, red albitepyrite (±Au) and chlorite-magnetite alteration zones. Gold occurs with pyrite within the intensely altered gabbro, along the margins of syn- to late-shear, quartz-rich, replacement veins.The Stog’er Tight gabbro served as a rigid body conducive to shear deformation and fluid penetration, whereas, its high Fe-Ti oxide content induced fluid oxidation and gold-pyrite precipitation. Hydrothermal alteration involved progressive CO2, S, Na, and LILE metasomatism, along with significant enrichments in the REE, HFSE, and Th in the high-grade ore zone. Temperatures of vein formation and alteration are constrained by oxygen isotope thermometry to be between 250°C and 480°C. Isotopic compositions of vein quartz from the Stog’er Tight prospect are uniform (??O = +12.5 ± 1‰) and fall within the range cited for many shear-hosted, auriferous quartz veins.A U-Pb zircon igneous age of 483 +3/-2 Ma for the Stog’er Tight gabbro is consistent with its stratigraphic correlation with other Ordovician ophiolitic and volcanic arc/back-arc assemblages in Newfoundland. The U-Pb age of a rare variety of hydrothermal zircon recovered from the high-grade ore zone directly constrains the timing of gold mineralization to 420 ±5 Ma, in accord with a major orogenic episode of Silurian age that produced many of the magmatic and metamorphic rock suites in north-central Newfoundland. Our results are consistent with a post-peak metamorphic, late-magmatic model for gold mineralization that occurred during the waning stages of Silurian orogenesis, driven by emplacement of I-type granitoid intrusions into the crust."

Jan 1, 2000

By A. Sheikh, S. Hardcastle

"Various methods of leaching are being used by Denison Mines Ltd. Uranium Operations. This study was designed to investigate the flood leaching operation of two parallel inter-connected stopes contained by pressure bulkheads. The teaching muck piles, created from large scale uppers production blasts, are aerated by compressed air lines laid beneath the pile prior to blasting.A SFr, tracer gas, injection technique has been employed to determine the post-blast integrity of the single-ended air distribution system. SF6 was injected into the compressed air line feed to the stopes and collected at borehole exhausts from the stopes in grab-sampling bags. Analyses of the air samples were performed with a gas chromatograph.The system was designed to give a sufficiency of oxygen to sustain bacterial activities used to enhance the leaching recovery in the muck piles. The results obtained indicated that there is a minor anomaly in the distribution system that may not be critical to the operation. Compared to an idealized case, the over-all efficiency of aeration throughout the muck is estimated at over 85%."

Jan 1, 1988

By H. Agnerian

"A survey of 925 mineral property transactions worldwide was carried out between 1987 and 2004. These mineral properties with reported Mineral Resources include 457 gold properties, 322 base metal properties, and five platinum group element (PGE) properties. Based on constant Canadian dollars, the results of the survey indicate that:• In general, unit metal values in the ground (e.g. $/oz Au or $/lb Cu) have kept pace with the changes in the respective metal prices during the period of the survey.• A general decrease in unit gold values in the ground has occurred from about $57/oz Au in 1987 to about $11/oz Au in 2002 for Canadian mineral properties, with the exception of a peak of $58/oz Au in 1996.• A similar trend for mineral properties has occurred in the United States, but with lower unit values, in the range from $1/oz Au to $10/oz Au during the last three years of the survey. • Unit metal values in the ground for gold properties in Canada were higher than for those in the rest of the world.• Unit metal values in the ground for copper properties in Canada were in the mid-range compared with other countries in the rest of the world; the United States and Australia were higher and Latin America, Asia, Africa, and Europe were lower than in Canada.• Unit metal values in the ground for zinc properties in Canada were also in the mid-range compared with other countries in the rest of the world; Latin America and Europe were higher and the United States, Australia, and Asia were lower than in Canada.• Unit metal values for nickel properties in Canada were highest compared with other countries in the rest of the world, followed by the United States, Australia, Africa, and Asia.• Gold values in the ground in Canada have ranged from 6% to 14% (with an average of approximately 10%) of the gold price.• The unit values of base metals in the ground have been in the order of 2% of the quoted metal price, during the period of the survey."

Jan 1, 2006

By A. J. Monhemius

"The paper reviews the history of modern iron control processes in hydrometallurgy. Particular attention is paid to the processes developed in the 1960s by the electrolytic zinc industry for the removal of iron from zinc sulphate leach liquors - namely the Jarosite, Goethite and Hematite processes. Problems faced by the industry in the safe disposal of the iron residues produced by these processes are discussed. The lessons learnt over the past half century by the zinc industry are projected on to the current efforts to develop hydrometallurgical processes for the treatment of copper sulphide concentrates. It is argued that any attempt to create a “hydrometallurgical copper smelter” is doomed to ultimate failure, unless and until methods are developed that can recover iron from solution in a form that can be directly utilised by the steel or pigment industries.INTRODUCTIONYou suddenly realise that age is catching up with you and that technology is moving on apace when you are asked to talk about the history of a process or a technology that you’ve grown up with. Such was my reaction when, out of the blue, I received an email last year from the chairman of the CIM’s Historical Metallurgy Committee, asking me if I would give a talk on the early developments of iron control in hydrometallurgy. Once I’d got over the initial shock of realising that I had now become living history, I was of course flattered that the invitation was to give a talk at the prestigious IMPC, a conference series that has been going for as long as I have been in the business. That this particular IMPC was to include the 4th Symposium on Iron Control in Hydrometallurgy, made the invitation even more appealing and appropriate, because I was the co-chairman of the First Symposium on Iron Control, together with my old friend, John Dutrizac (known by many as Dr Jarosite), which was held 30 years ago in Toronto.first became involved with iron at the very start of my career in hydrometallurgy – the research topic for my Masters degree thesis at UBC, back in the mid 1960s, was “Reductive leaching of Goethite with SO2”. My thesis supervisor was the late Professor Ian Warren, who himself was a protégé of Professor Frank Forward, one of the founding fathers of modern hydrometallurgy. Little did I realise at that time, now 50 years ago, that the problem of iron and how to deal with it in hydrometallurgical processes would be a theme that followed me throughout much of my 40-year career in academia."

Jan 1, 2016

By Benjamin A. Allou

La seule production de columbo-tantalite réalisée en Côte d?Ivoire est effectuée dans les éluvions et alluvions du gisement d?Issia, localisé au Centre- Ouest de la Côte d?Ivoire. Même si un lien direct avec les roches granitiques est suspecté, aucune attention particulière n?a été accordée à l?étude de la minéralisation primaire en relation avec l?évolution des granites et des pegmatites associées. Ces granites, qui sont en intrusion dans les roches sédimentaires du Protérozoïque inférieur, comprennent : le granite orienté à deux micas (Lobo), le granite orienté à muscovite dominante (Bitapia) et le granite porphyroïde non orienté à muscovite dominante (Issia). Les résultats de cette étude indiquent que les pegmatites à Nb-Ta-Be-Li sont liées au granite de type Issia. Les observations de terrain et les analyses sur roche totale des granites montrent que: (1) les trois principaux granites de la région sont de type- S et peralumineux dans leur composition, (2) ils ont été formés pendant la période tardi- à post-Éburnéenne, (3) le granite d?Issia fut le dernier à se mettre en place. Les pegmatites liées au granite d?Issia ont été classées en quatre types : Apegmatites stériles; B- pegmatites à Be; C- pegmatites zonées à Nb-Ta-Be; et Dpegmatites zonées à Be-Nb-Ta-Li. Les pegmatites zonées comprennent les zones suivantes: I- zone à aplite; II- zone graphique; III- zone à albite, microcline, béryl et columbo-tantalite; IV - zone à microcline massive; V- zone à quartz. Ces pegmatites présentent une zone d?altération métasomatique externe. La minéralisation de Ta, Nb et Be est liées à la zone III des pegmatites de types C et D, et celle de Li est associée aux greisens qui peuvent être observés n?importe où dans les pegmatites de type D. Les données de terrain et de laboratoire indiquent que le granite d?Issia est la roche parentale des pegmatites à éléments rares de la région. Les pegmatites minéralisées sont distribuées seulement autour du granite d?Issia et les patrons des terres rares des granites et ceux des pegmatites à éléments rares sont très similaires. Les analyses de la composition totale montrent un lien génétique entre le granite d?Issia et les pegmatites à éléments rares. Il est suggéré que les pegmatites ont été formées durant le transport et la cristallisation fractionnée du magma.

May 1, 2003

By R. Amelunxen

"The molybdenite associated with copper porphyry ores is generally treated in a flotation circuit consisting of a separation and a cleaning section. In the last few years column flotation cells have replaced the numerous counter-current stages that were previously used in the cleaning section. Despite this, little has been published regarding the number of column cleaning stages required. Therefore a Moly flotation database is assembled with the objective of verifying the existence of a common upgrading profile. This can then be used as a guide in the prediction of the number of stages required to achieve a given concentrate grade.INTRODUCTIONAlthough the first use of Column Flotation was on copper flotation products, the popularity and understanding of their operation was not really achieved until they were widely implemented in Moly circuits in early 1983. The use of columns in Moly plants has since left a legacy of information, both published and unpublished. The data collected since that time has been used primarily used to establish column operating parameters and to determine upgrading potential within the circuit.Byproduct Moly generally occurs with porphyritic copper ores in concentrations less than 0.1% MoS2. As such, piloting a new moly ore to produce, say 5 Kg/Hr MoS2, in a slurry approximately 1 Lt/min (at 10% solids), requires a moly plant feed of about 570 Kg/Hr, which translates to a mill feed rate of 200 to 800 Tonnes per day (depending whether you deal with Chilean or Canadian ores). Piloting Moly for any lower tonnage would reduce the accuracy of the testwork.Thus a need exists to collect operating data in order to establish the existence of process relationships that could be used for feasibility and design purposes.The object of this paper is to expose a preliminary relationship that could be used for the purposes described above and to apply the findings to a preliminary design of a moly cleaning circuit flowsheet."

Jan 1, 1990

By V. Dinesen

"Grinding is simply the function of reducing particles in size or creating new surface areas. This may be accomplished by many means but we will only concern ourselves with the continuous grinding process as performed in a revolving drum or mill, containing a grinding media. Such a mill consists essentially of a feed head, a cylindrical shell section and a discharge head. To prevent internal wear of these parts it is customary to attach replaceable linings over the wear areas. The specification and design of these mill liners is more important than generally conceded. As they reduce the effective internal volume of the mill, they will consequently affect the whole mill ·design and operation.A number of mill designs of various sizes are available for combined crushing and grinding of materials within a wide size range. For simplif1cahon purposes we will refer 1n particular to conditions relating to standard mill shapes having a length which is greater than the diameter. Such mills usually rotate at speeds between 60% to 85% of the critical speed and may, depending on the grinding media used, be classified as rod mills, ball mills and pebble mills.LINER MATERIALSA great variety of materials have been and are being used for mill linings. These include wood, ceramics and cements, rubber and plastic compounds, rolled and forged steels, cast steels and cast irons, both plain, alloyed and specially treated.The choice of a liner material depends on many factors. In both dry and \\.:et grinding, it may be necessary to consider product purity, colour, chemical reaction etc. but for our purpose we \viii refer to wet grinding operations as generally used within the mining industry."

Jan 1, 1972

By Jean G. Fortin

The manufacturers' proposed technology has been a key factor in selecting production, mobile and fixed equipment in order to achieve the targets set in our 2026 mining plan. This paper will present an overview of the most recent technologies adopted by Québec Cartier Mining Company for communications, power supply, dewatering, drilling, loading, hauling and processing. All these new technologies contribute to the improvement of our day to day operations while operating with a state of the art asset reliability program.

May 1, 2007