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By M. J. Michaud, M. J. Lavigne

"A cornerstone of any successful mining project is an understanding of the mineral assemblage and metal distribution comprising the deposit. Knowledge of the precise mineral/ metal zoning enables an operation to utilize different mining and processing methods optimized for different parts of the deposit. The Lac des Iles mine, located in northwestern Ontario, is one operation that depends on a good understanding of these issues. Current resources for the Roby Zone total 94.1 Mt grading 1.66 g/t Pd, 0.18 g/t Pt, 0.14 g/t Au, 0.062% Cu, and 0.053% Ni.The Roby Zone occurs within the gabbroic portion of the Lac des Iles intrusive complex and consists of three compositionally and texturally different ore types with variable PGE, base and precious metal contents. PGE occur as sulphides and bismuthotellurides in net-textured sulphides, coarse sulphide blebs and as finegrained inclusions within secondary silicates.Knowledge of the precise mineral/metal zoning has directly and indirectly improved several operational aspects, including resource modelling, mining, and processing. For example, metallurgical recoveries have been increased by up to 3% to 5% and concentrate grades have increased by up to 100%. IntroductionLac des Iles Mines Ltd., a wholly owned subsidiary of North American Palladium Ltd., owns and operates a 3000 t/d open pit mine and concentrate facility, located 100 km north of Thunder Bay in northwestern Ontario. The Lac des Iles PGE-gold-copper-nickel mine has been in commercial production since 1993 and in 1997, produced 1.8 million grams of palladium, 127 000 g of platinum, 114 000 g of gold, 438 000 kg of copper and 354 000 kg of nickel (North American Palladium Ltd., 1998).Under the Industrial Research Assistance Program (IRAP), a two-year study of the mineralogy of the Roby Zone was undertaken with a goal of improving the profitability of the mine. Geological mapping, petrography and geochemistry of the Roby Zone were completed during this study. Utilization of the detailed mineral/metal zoning identified as part of this study was implemented at the mine and shown to positively impact many operational aspects including mining and processing."

Jan 1, 2003

By C. S. Maggs, L. Shwydiuk, H. W. Newcomen

The southwest wall of the Lornex Pit at the Highland Valley Copper mine has been experiencing slope displacements since 1978. Measures to manage the displacements on previous pushbacks have included stepping out, scheduling pushbacks to unload the crest of unstable areas, slope dewatering and mining with intensive slope monitoring. The final pushback on this wall is currently being mined and substantial modifications to the slope geometry could prove to be uneconomical. As a result, a campaign of surface water collection and diversion, horizontal drainhole drilling and deep well drilling is currently underway to maintain an acceptable degree of stability to the end of mine life. The various factors contributing to instability, including engineering geologic controls, rock mass strength, and surface and groundwater hydrology are presented. Movement trends, displacement magnitudes and stability analyses results are also discussed.

Jan 1, 2003

By T. G. Joseph

"The Oil sands-Equipment Interactions Program (OsEIP) is a collaborative research venture between Syncrude Canada Ltd., James Progithin International Ltd. (JPi), the University of Alberta, P&H MinePro, and Caterpillar Inc. The objective is to better understand the behaviour of oil sands as it interacts with mining equipment, in particular, large trucks and shovels. With a move to ever larger equipment, mining oil sands of highly variable bitumen content, ground stability comes into question. This paper outlines this aspect of OsEIP and provides some insight into how some of the findings enable an improved understanding of oil sands behaviour that may impact large equipment design, operational and maintenance strategies. IntroductionThe mechanical behaviour of oil sands in the underfoot and in the face yields some of the harshest stability and digging conditions of any mining environment. High maintenance costs from truck and shovel fatigue failures predominate as a result of ground stability issues. Wear rates of shovel and dozer ground engaging tools (GET), rollers, roller paths and crusher screens result in costly and frequent replacement, or even more frequent and costly sacrificial wear zone building. From the shovel face to the crushers and screens, dry oil sands mechanics affects the degree of fragmentation and, ultimately, bitumen production.An increased knowledge of the behaviour of oil sands with respect to stability, fragmentation and abrasion, etc. would enhance the long-term equipment design process at the vendor level, and provide the end user with improved short-term operational guidelines and long-term strategies for future purchases and operation. Truck vendors recognize that the interaction between operator, seat, frame, suspension, tires and oil sands is unclear, and must be better understood before proceeding to next generation designs. Similarly for shovel manufacturers, the relationship between bucket/dipper motion, carbody, side frame, rollers, track and oil sands follow in the same vein."

Jan 1, 2002

By P. Massi

"Wholly owned by the Coniagas Mining Company, the oldest continuously listed mining company on the Toronto Stock Exchange, St. Andrew Goldfields is located on Hwy. 101 approximately 30 miles east of downtown Timmins, Ontario. Geographically situated on the Porcupine-Destor Fault, the mine and mill in Stock township is positioned in the heart of Northeastern Ontario's goldmining communities.In July 1988, a 600 ft. shaft, hoist, and compressors were already in place when construction started on a 500 T.P.D. capacity C.I.P. mill and crushing plant.By June 15, 1989 the mill was commissioned and attained the design capacity by August of that same year. Since then, changes to the circuit have increased throughput to 900 T.P.D. from two significantly different ore sources.Meeting the Ministry of the Environment's guidelines is an ongoing commitment utilizing the Inca S02 process in line between the tailings pond and secondary polishing pond.INTRODUCTIONExploration on what is now known as St Andrew Goldfields' Stock Township Mine was carried out ln the early l960 1 s by Hollinger Mines Ltd. The property was acquired by Quebec Sturgeon River Mines 1n 1973 and the main shaft was started ill 1979.When St Andrew Goldfields was incorporated 1n 1983, exploration and development commenced to identify the ore body. The company decided 1n 1987 to bring the Stock township property into production after an extensive feasibility study and testwork at Lakefield Research in Toronto. Leslie Engineering was contracted to design, engineer and procure al 1. equipment from the coarse ore bin to the tailings distribution system and backfill plant"

Jan 1, 1992

"Placer Dome Inc.'s Dome Mine is located in South Porcupine, Ontario and has been in production since 1910. In the past, the mill leach circuit was preceded by preaeration and primary filtration circuits. These circuits were operated to overcome the effects of pyrrhotite in the ore which reacts with cyanide to form cyanates and thiocyanates and also consumes oxygen.In early 1989, primary filters were by-passed for an extended period. Actual plant results showed no affect on gold recovery or cyanide consumption so the circuit was left off-line permanently with significant cost savings.In 1990 it was determined that considerable savings could be realized underground if backfill storage facilities were located in the mill. It was decided to convert the preaeration pachucas to backfill storage tanks on a trial basis. The trial proved successful with no effect on recovery or significant increase in reagent consumption occurring due to the elimination of the preaeration circuit. The converted pachucas worked well as backfill storage tanks.Modifications such as these have helped to keep the Dome's millings costs among the lowest of Canadian gold producers."

Jan 1, 1992

By Steve Lalancette

Centre Jardin Lac Pelletier (CJLP) has been a leading actor in the revitalisation of closed mining sites in northern Québec for over 20 years. Over that period, CJLP developed a cost-efficient technique that transforms sterile mining residue into a substrate able to support a resilient ecosystem. Using a unique mix of organic matter, fertilisers and selected plant species, this technique rapidly builds a microorganic fauna and a layer of humus that will sustain the creation of vegetation coverage. The coverage is composed of over 13 different plant species, each having a unique role in the development of a resilient ecosystem, from soil stabilisation to nitrogen fixing. Considerably less expensive than traditional methods using civil engineering techniques, it does not require the use of heavy machinery or the spread of topsoil. This technique has been successfully used to restore over 20 sites in Québec such as Joutel, Yvan Vézina and Louvicourt. It is a proven technique that has passed the test of actual implementation. The presentation will review the biological, production and economic aspects of the technique through the revitalisation of the Joutel site.

May 1, 2011

By L. W. Hamel

"DUST CONTROL - GRANISLE COPPER LIMITEDINTRODUCTIONGranisle. Copper Limited is located in the north-central region of the Province of British Columbia, approximately 200 road miles north-west of Prince George. Mill startup was in November, 1966, at a rate of 5,000 tons per day, expanded to 13,000 in 1973. The primary crushing rate is 1,200 tons per operating hour, and the secondary 750, and they can be operated jointly or separately.DUST COLLECTION SYSTEMS There are seven dust collection systems ventilating the crushing and grinding complex. The individual pickup points are depicted on Figure 1 -""Crushing Plant Flowsheet"", and Figure 2 - ""Concentrator Flowsheet"", e.g. 1A, 1B, 3C, etc.System No. 1 - Primary Crusher The feed rock box of the Allis-Chalmers superior 42-65 primary crusher is ventilated by 19,000 CFM of air exhausted directly to atmosphere by a Sturtevant 426 M fixed discharge fan.No. Dust Pick Up Point CFM lA Crusher Feed Rock Box 19,000System No. 2 - Primary Crushing and Screening System No. 2 ventilates the primary crushing and screening equipment. A total of 19,000 CFM of air is exhausted by a Sturtevant 426 M fixed discharge fan through a Howden Type S - size 75 cyclone locally modified for wet scrubbing."

Jan 1, 1976

By V. I. Lakshmanan, D. A. Mackie

"1. INTRODUCTIONIn the past two decades, low-grade gold and silver ore bodies in the United States have been exploited by heap leaching, primarily with sodium cyanide solutions. This method has proven to be a viable alternative to conventional milling due to its low capital and operating costs. Successes have been made, particularly in Nevada, where ores are well oxidized and the climate is conducive to this method. in recent years, heap leaching has been tried in northern latitudes with some success, however, in using this method, operators face more severe limitations than do their neighbours to the south.This paper evaluates the limitations of heap leaching with particular emphasis on northern climates and introduces an alternative method to recover precious metal values in a continuous vat. This proprietory technology, known as the Mackie Vat Leaching Jig, shows promise, with improved gold recovery and potential to operate in cold climates.2. WHAT ARE THE LIMITATIONS TO HEAP LEACHING?Heap leaching of non-refractory ores is subject to the following limitations:1. Minimum amount of free gold and nuggets in the ore.?. Minerology of the ore--accessibility of gold to lixiviant.3. Minimum particle size and size distribution of crushed product to allow percolation of lixiviant through the heap.4. Minimum amount of clays or clay-like slimes that can cause coating of ore particles and channelling of lixiviant.5. Minimum strength of ore particles or agglomerations to allow economic height of heaps to be built.6. Amount and suitability of real estate.7. Amount and type of precipitation.8. Ambient temperatures.9. Possible poorer lixiviant diffusion.10. Possible lower oxygen content in dissolved cyanide solution with higher heaps, particularly with ice and snow cover."

Jan 1, 1989

By R. S. Fukuhara, M. J. Allan

"Highmont, a wholly owned subsidiary of Teck Corporation, operates a 25,000 ton/day mine and concentrator located in the Highland Valley of British Columbia. Construction of the plant commenced in the spring of 1979, and production from one grinding line began in late December 1980. The second grinding line began production in March 1980.The ore body consists of two main zones, the east and west pits, containing 134 million tons of ore, averaging 0.26% Cu and 0.27% Mo. Mineralization consists mainly of chalcopyrite (2/3), bornite (1/3), and molybdenite.The concentrator design incorporates an A-B-C grinding circuit (auto mill ball mill - crusher), followed by bulk flotation, copper-moly separation and leaching for moly concentrates. The two grinding and bulk flotation circuits are parallel and independent. Concentrate storage is provided between bulk flotation and copper¬moly separation and also ahead of molybdenite leaching. The plant design has been previously described in some detail. (""THE HIGHMONT CONCENTRATOR"" by C. V. Sibbald, CIMM Bulletin, March 1981).This paper will outline some of the problems associated with the construction, startup and early operation phases of the concentrator. The objective is to help others avoid some of the potential pitfalls by outlining those areas where problems occurred, or where things went well. Criticism of design or equipment is not intended."

Jan 1, 1982

By Michel Rodrigue, Sylvain Duchesne, Louis Racine

"LocationThe Louvicourt mine is located 20 km east of Val d'Or in Abitibi, in the northwest part of the province of Quebec. The mine is located on Highway 117 connecting Val d'Or to Montreal and very close to the main railway networkHistoryFive successive exploration attempts by Aur Resources resulted in the discovery of the large Louvicourt orebody in June 1989. Construction of the surface and underground infrastructures commenced in the spring of 1991. Milling operations commenced in July 1994. The entire project cost CDN$290 million, almost CDN$20 million less than initially estimated. The concentrator infrastructure cost CDN$64 million.Louvicourt mine is owned in partnership by Novicourt Inc. (45%), Teck Corporation (25%), and Aur Resources Inc., the administrator (30%).Brief DescriptionLouvicourt mine is the largest producer of base metals (Cu and Zn) in Abitibi-Temiscamingue. Its average daily production is nearly 4300 t of ore, for an annual production of 200 000 t of copper concentrate (28% Cu) and 33 000 t of zinc concentrate (57% Zn). After only a few weeks of operation, it had attained its objectives for the most part, and operations continue to be improved."

Jan 1, 2000

By S. Haggarty

"Wholly owned by Corona Corporation, the Nickel Plate Mine is an open pit, gold mining operation located near Hedley, 50 km west of Penticton, in Southern British Columbia.Milling capacity is 3,400 SDT /Day with an average feed grade of 0.080 Oz Au/Ton. Gold processing involves three stage grinding including tertiary pebble milling, two stage cyanide leaching and filtering and Merrill-Crowe zinc precipitation.A summary of process improvements required to increase milling capacity above the initial design tonnage of 2, 700 SDT /Day are described -Installation of a 42"" x 65"" Allis Chalmers Gyratory crusher replacing a 42"" x 48"" Traylor jaw crusher.Installation of polyurethane screen panels replacing woven wire cloths on an 8' x 20 ft triple deck screen.Installation of a hopper clarifier to reduce filtrate turbidity.Automated control of solution balancing and effluent treatment circuits.INTRODUCTIONThis paper describes mining and milling practices at the Nickel Plate Mine and details post start-up process modifications which were required to attain design tonnage.Wholly owned by Corona Corporation, the Nickel Plate Mine is an open pit, gold mining operation located near Hedley, 50 km west of Penticton, in Southern British Columbia.Mining capacity from the open pit is approximately 32,000 TPD with an average waste/ore ratio of 8.4:1.Milling capacity is 3,400 SOT/Day, above initial design tonnage of 2,700 SOT/Day. Feed grade averages 0.08 Oz Au per ton yielding 85,000 troy ounces of gold per year."

Jan 1, 1991

By R. E. Jones

"Crusher sizing and application in mining operations is the selection of a crusher or a series of crushers to reduce run of mine ore to a size suitable for either autogenous or conventional grinding. It is important that the crusher or crushers be sized to operate within the range to which they have been designed. By the range to which they have been designed, we mean that the reduction ration must be held between specified limits. Reduction ration is the relationship between feed size to product size.In todays plants reduction is usually accomplished in three stages by primary, secondary and tertiary crushers.Primary crushers are either jaw or gyratory and are designed to handle run of mine feed at an open side setting of 5-1/2” to 7”. Reduction ration should not exceed 7 to 1.Jaw CrushersThe model size of a jaw crusher signifies the feed opening. A model 60 x48 jaw has a feed opening 60” wide by 48” long. The 48” is the dimension between the top of the swing jaw and the top of the stationary jaw. The 60” is the width between the two side frames. The crusher open side setting is the discharge opening at the bottom of the crushing chamber with the jaws in an open position. When corrugated jaw plates are used, the open side setting is measured from tip of one jaw plate to the valley of the opposite jaw plate. If a jaw crusher has a 6” open side setting with a 1” jaw motion, you could also say it has a 5” closed side setting."

Jan 1, 1974

By K. G. Stowe

"1. Introduction Mattagami Lake Mines and Orchan Mines operate zinc copper mines adjacent to one another near Matagami, Quebec, situated approximately 300 kilometres north-east of Rouyn-Noranda. (Note: Mattagami Lake and Orchan are in the process of being absorbed by Noranda Mines and will become Noranda Mines-Matagami Division). Both concentrators began operations in late 1963.The Mattagami Lake concentrator is capable of treating up to 3,500 metric tons per day of massive sulphide ore with a mineral composition shown in TABLE 1. The Orchan concentrator consists of two separate circuits - the Orchan circuit with a capacity of 1,050 metric tons per day and a custom circuit with a capacity of 825 metric tons per day. Throughout its operation, Orchan has custom milled ore from several smaller deposits in the Matagami district."

Jan 1, 1979

By J. Lee, R. G. Rosehart

"The basic problem of arsenic contamination from mine water is discussed. Effective methods of removal involving chemical precipitation, activated carbon adsorption, ion exchange and reverse osmosis are discussed. As well as an economic analysis, detail is also paid to other ions in solution which are removed simultaneously.INTRODUCTIONThe object of this paper is to review arsenic and its removal from gold extraction plant effluents. The first method considered is chemical precipitation. A second method is sorption processes, such as ion exchange resins and activated carbon adsorption. A third method is the possible application of reverse osmosis for the treatment of mine waste waters containing arsenic.Arsenic pollution in the gold mining communities of Canada and Ghana have been extensively studies (l, 2). Lynch(3) Shabunin, Gutman and Kogan( 4), Hollo, Troth, Vennes and Illinigi (5) and Hau(6) have reported their removal methods of arsenic by chemical precipitation, ion exchange and biological methods. Their conclusions were that the precipitation with Fe2+ and Fe3+ ions was most effective.Scope of the ProblemInitial aspects of this research program involved a detailed analysis of the operation of a gold extraction plant located in Canada. The name and location of the mine is proprietary information. Figure 1 gives a basic process schematic with the main tailing streams identified.Table 1 gives information as to the various mine streams and their physical and chemical composition. In this study, primary attention is paid to the removal of dissolved arsenic from waste waters. Solids from this type of operation can always be back-filled. As could be anticipated, the dissolved As content of the primary flotation tailing stream is very low. The dissolved As level in the secondary processing stream and the roasting quench water is quite high. The reason being that at this stage of the process, the arsenic has been freed from the arsenopyrite forms."

Jan 1, 1972

By Peter Raziszewski

"A ball charge dynamics model is presented. Simulation results are compared with observed data showing good correlation. Based on the charge dynamics models, a liner wear model is presented along with some wear simulation results. Using the charge dynamics model with the liner wear model, it is possible to envision the predictions of mill power consumption as a function of liner wear. Further work is needed to validate the liner wear model.IntroductionFrom a process control point of view, industrial systems can be considered stationary or non-stationary. For example, the physical properties, such as geometric and/or material, of a system considered stationary do not change with time. However, this is not true for non-stationary systems such as those found in the mining industry where process dynamics are often violent with wear being an intrinsic process phenomenon.In this paper, a model for ball charge dynamics will be presented along with a description for liner wear. Simulation results for power draft prediction using the charge model will be compared with observed data. Further, liner wear results will also be presented."

Jan 1, 1997

By N. I. Basuki, E. T. C. Spooner

"Abstract - More than 2800 published fluid inclusion data (primary inclusions) from eighteen typical Mississippi Valley-type (MVT) Zn-Pb deposits and districts were examined to study possible relationships between MVT fluid properties and metal tonnages and ore grades. The mean Th and salinity values for fifteen MVT deposits and districts are 122°C ± 21°C and 20.7 ± 2.6 wt% CaCl2 equivalent, respectively. In general, temperatures increase from pre-ore to ore stages, and salinities decrease from ore to post-ore stages. From post-ore to late calcite stages, salinity and temperature decrease with various trends within specific districts.Several conclusions are drawn: first, results show that Hanor’s (1996) salinity threshold for metalrich basinal fluids applies to typical MVT ore fluids (~16 wt% CaCl2 equivalent). Second, the lower limit of mean Th values of measured MVT deposits and districts (n = 15) of ~75°C is similar to Hanor’s (1996) observed temperature threshold for metal-rich basinal brines of ~60°C (n = 224). Third, there is no statistically significant relationship between fluid inclusion homogenization temperatures (Th) and metal tonnages or ore grades. Fourth, there seems to be a tendency for large tonnage districts/deposits to be associated with mean fluid salinities that are relatively low (~16 to 21 wt% CaCl2 equivalent) within the overall range of salinity means (~16 to 26 wt% CaCl2 equivalent). There is also a correlation between higher ore grades and higher salinities. Finally, comparison with other sedimentary rock-hosted Zn-Pb deposit types shows a trend of salinity decrease and temperature increase from MVT, sandstone-hosted and diapir-related Pb-Zn deposits, to vein-type and Irishtype Pb-Zn deposits, and then to sedex deposits. However, more data are needed for sedex deposits. The salinity threshold for significant Zn-Pb transport decreases to =~10 wt% CaCl2 equivalent at ~250°C. This study suggests that fluid inclusion analysis during exploration may be useful in assessing ore-forming potential (threshold salinity) and possible ore grades (salinity)."

Jan 1, 2002

By George Hope, Brigitte Lacouture

"The Red Dog mine has increased mill throughput most years since start-up. Although flotation equipment has been added over the last 10 years, the Red Dog metallurgical performance has been restricted by a lack of adequate flotation capacity. Two reduced tonnage trials conducted in 1997 as well as numerous SAG relines have consistently indicated the potential to significantly increase both zinc concentrate recovery and grade with additional flotation capacity. Later in 1999, a new circuit was designed with increased flotation capacity while simplifying the current circuit, providing for three stages of dilution cleaning, and creating a retreat section. The purpose of the retreat section is to target the more complex particles and allow the chemical environment to be fine tuned for improved iron depression. In total, 21 Outokumpu OK50 (50 m3) mechanical flotation cells and four 3.66 mØ column cells were added to the current flotation circuit. The VIP (value improvement program) mill optimization project is also addressing thickening, water treatment, and power generation issues and has a total budget of US$105 M. Start-up of equipment was phased in to minimize the impact on current operations and the project was completed by the end of 2001. IntroductionRed Dog Operations started production in November 1989. The mine is located above the Arctic Circle in northwest Alaska. It is linked by an 80 km road to a port-site facility where the concentrate is stored. Concentrate is shipped to markets throughout the world during the one hundred days of open seas. As of January 2002, the Red Dog main pit had 38.4 Mt of reserves grading 19.2% Zn, 5.3% Pb, and 102 g/t Ag. Additional reserves and resources contribute an additional 72 Mt at 15.6% Zn, 4.2% Pb, and 78 g/t Ag. Red Dog is a Mississippian to Permian, black shale-hosted, zinc-lead-silver deposit located in the DeLong Mountains, western Brooks Range, Alaska. All the rocks associated with the mineralizing event are considered to be part of the exhalite rock package. Silicification was a dominant component of the mineralizing event and the host shale has been silicified and locally resembles a chert. The major sulphides in decreasing order of abundance are sphalerite, pyrite, marcasite and galena. Most of the deposit’s silver occurs within the crystal structure of the galena. The dominant ore mineral, sphalerite, is very fine grained to amorphous and is commonly intergrown with silica. Ore textures are massive, fragmental, chaotic, veined and rarely show classic sulphide sedimentary layering. The upper portion of the orebody has been physically and chemically weathered. Oxidation has altered the sulphides to sulphates. The zinc and iron sulphates are very soluble and are readily depleted from the weathered cap, while the lead sulphate is residual and is, therefore, enriched."

Jan 1, 2003

By Arthur D. FitzGerald

EDC established an Environmental Review Framework in 1999. Throughout the early fall of 2001, the Corporation held public consultations across Canada to strengthen that framework, leading to a public release on November 15, 2001 of a report summarising the results of these consultations. Following this, the Corporation implemented strengthened environmental review requirements in the form of its Environmental Review Directive, in compliance with legislated amendments to Canada?s Export Development Act that went into effect on December 21, 2001. Over the past few years, there has been a global trend towards an increase in the social and environmental requirements of multilateral/bilateral financial institutions and export credit agencies. More recently, this activity has focussed on capturing institutions that have not yet adopted similar requirements and, more specifically, on developing a convergence of the requirements from institution to institution. This paper describes EDC?s new ERD and some of the initiatives that have taken place or are in process that are moving international financial institutions toward converging their environmental and social requirements for projects in the private sector.

May 1, 2002

By B. V. Knelson

"GENTLEMEN:This paper will deal with centrifugal separation - theory and practical, and since the Knelson Concentrator is the only centrifugal concentrator with a properly fluidized bed, this paper will cover the Knelson Concentrator and its technical and structural advances over the last five years. As I am the person with the most experience in this line, I guess I am some kind of an expert; what kind I’m not sure, but some kind.This type of concentrator truly was developed because I’m lazy and I constantly look for easier ways to do things. My experience in the mining industry was very limited but I did realize in looking at placer operations, which is the application where I spring from, that it was tremendously labour intensive and my first reaction that ""my god, there must be some method or way-of handling product in a more efficient (and you can read that as being able to quickly recover very fine particle gold) way than was being shown at that time"". So, the Knelson Concentrator was born - about 6 or 7 years later. Our first attempt was a cone with about the same degree of slope as our present machine and since we had no knowledge of vibration dampening and centrifugal forces at that point, it was just an idea that this should work.Our first run was one of twenty minute duration. We did make that first machine variable speed by a mechanical belt system and we found that at about 240 rpms we were virtually shaking the gravel plant apart that we were attached to. So the first run was twenty minutes and back to the drawing board. However, that first run produced a concentrate so superior to anything we had seen previously, that we knew without any question, we were definately and accurately on the right track."

Jan 1, 1985

By L. K. Daneshmend

"Competitive pressures dictate that the mining industry moves to larger mobile underground haulage equipment with more advanced equipment mechanization, higher levels of autonomous operation of machines, and longer periods between access by maintenance personnel. Since such new machines will of necessity be more complex than existing designs, machine reliability has become a key issue in progressing toward advanced mobile underground haulage equipment. Reliability and maintainability models of such equipment are practically non-existent in the literature. This paper addresses the issue of reliability and maintainability of mobile underground haulage equipment on two fronts: reliability modelling to enhance decision making for maintenance planning; and reliability simulation to enable evaluation of more rigorous production planning scenarios. A case study from a gold mine in the Chilean Andes is presented, for which reliability models of mobile underground haulage equipment, specifically load-hauldump vehicles and underground haul trucks, are developed, and a reliability-based simulation implemented. IntroductionMaintenance accounts for 20% to 35% of the overall operating budget for a typical underground operation, and hence represents the largest portion of the mine’s controllable operating costs (Cutifani et al., 1996; Campbell, 1997; Goddard, 1998). This, coupled with the fact that industry today is faced with an ever more complex and demanding marketplace, has led to an increasing interest in methods to reduce maintenance costs.Although significant effort has gone into developing effective maintenance strategies for industry in general, application of these to the"

Jan 1, 2003