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By Jean-Luc Collins

"This new tool can be used as a quick guide f or the assessment of the potential economic wealth of any risky capital project. It does provide an unambiguous recommendation of the type ""go or no go"" to the decision-maker simply by comparing two different ratios profit/investment. One ratio determines the minimum value required to at least break even while the other measures a probable value based on the asymptotic theory of statistical extremes.Its application is briefly illustrated by means of an underground gold mine extension project, an oil sands mine project and a polymetallic open pit project.Once a favourable recommendation has been obtained then a detailed ""cash flow after taxes"" analysis can be carried out for the project.IntroductionMany tools are used in financial decision-making such as the payback period, the discounted cash flow, the internal rate of return and the wealth growth rate (Berry , 1971).These tools are useful and meaningful in evaluating normal projects closely related to regular business where the number of assumptions made is usually very small and where the cost of capita! is usually selected as a discount rate or a hurdle value. In situations where a significant number of assumptions have to be made,two problems can emerge, namely:I. the risk involved is underestimated leading to a potential financial disaster; or2. a good opportunity is lost because the approach used in evaluating the project is too conservative.Each assumption has its own degree of uncertainty and it is well known that combining uncertainties together can lead to a total uncertainty of critical proportion. The easiest way to account for risk is to increase the discount rate or the hurdle value, but this approach alone is quite subjective and can easily lead to the problems described above."

Jan 1, 1993

By Barry W. Schmitke, J. M. Marino

"Cigar Lake Mining Corporation is presently operating an underground test mine in northern Saskatchewan, with a view to developing a high grade uranium deposit. The mining test is intended to demonstrate that the innovative mining methods designed are safe and economical. Two vertical mining methods are considered for the test:• box hole boring from the lower level;• blind boring from the upper level.In both cases, it is anticipated to freeze the ground before excavation to ensure hole stability and limit the inflow of water. Special care will be taken to minimize radiation exposure of personnel.Remote controlled equipment will be used where applicable.The access to the orebody was an important component of the test. After shaft sinking to a depth of 500 m, development work commenced at the 420 level in fractured sandstone which was grouted to restrict the inflow of formation water. The drifting continued in a section of poorly consolidated sand, clay and sandstone; this area was frozen to allow stabilization prior to excavation. At the 480 level relatively little water was encountered in the altered basement gneiss and grouting was not necessary; however, extensive ground support was required in the soft ground areas."

Jan 1, 1992

By P. Lausch, Z. X. He, J. F. Archibald

"Documented underground fill failures have resulted because of the lack of adequate knowledge concerning fill strength and other physical parameters, as well as to a lack of consistent quality of fill materials being used by operators. On the basis of literature review and correspondence with backfill operators at 18 mines throughout the province of Ontario, non-systematic quality control procedures have been shown to exist, both within different levels of single operations and between separate mining operations, which act to provide inferior engineered fill materials and erratic application response in situ.Assessment of existing procedures set by mine operators for determining backfill physical parameters, and recommendation of optimum fill material testing and manufacturing guidelines are presented in this paper.A series of standard fill characterization test procedures are recommended to provide substantial, though not comprehensive, fill behaviour review. The purpose of these recommendations is to propose industry standards for backfill quality review. Data acquired could be utilized for fill design functions and as a means of comparing fill quality parameters between sites in a regular and more systematic fashion than is presently done."

Jan 1, 1993

By Keith Jones, Largo Albert

"Decelerometer testing of a rigid guide system in a mine shaft pro vides usefuI information to operating and maintenance people. High acceleration/deceleration rates can lead to high maintenance costs to bath conveyances and shaft and can also present an operating risk . Possible disastrous results in the shaft have been avoided by restricting the maximum conveyance speed until the shaft and/ or conveyance problems have been solved.The test instrument is a valuable aid especially during commissioning or updating of a hoisting installation. High acceleration/deceleration rates also lead to reduced hoist rope life. During the past fourteen years, a total of 15,000,000 feet of testing was performed in 74 assorted shaft compartments.Based on this experience, it is possible to establish acceptable conveyance maximum speeds provided that all other conditions in the shaft compartment are normal. The body of the paper will present examples of several tests made under actual operating conditions.IntroductionMore and more mine operators are recognizing the real value in the use of the decelerometer for determining the state of shaft guide alignment in their shaft compartments , not only during the initial mine start-up periods, but also on a regular basis while the mine is in production.Decelerometer testing, is a technique in which an accelerometer , commonly known as a decelerometer, is used for measuring conveyance acceleration/deceleration in a lateral plane. lts purpose is to determine the severity of shock loads produced by misaligned shaft guides. Testing is performed by mounting the instrument on the conveyance and operating the conveyance (empty and loaded) at various speeds up to and including full speed . However, full speed may not be attained due to conditions indicated by the tests. These conditions may present an operating risk to the plant."

Jan 1, 1984

By David J. McDougall

"IntroductionThe production of pig iron, wrought iron bars and castings in Quebec during the 18th and 19th centuries has been so closely identified by historians with the Forges du St. Maurice on the St. Maurice River a few miles north of Trois Rivières (Three Rivers), that one is sometimes left with the impression that it was the only iron works that ever operated in the province. There were however, about twelve others, one of which was so completely re-built that it should probably be considered as a separate entity. All but two were constructed after the midpoint of the 1800s, coinciding with the growing Canadian demand for ""charcoal pig"" for railway car wheels and castings for industry, and about half of them were technically, if not economically, successful. The misconception about the Forges du St. Maurice may have come about either because of its long history of somewhat less than continuous production over a century and a half, or a tendency of Quebec historians to concentrate on events in the French-Canadian rather than the English-Canadian milieu, but whatever the reason, the other Quebec iron work s have been generally ignored. All but one of the Quebec blast furnaces could be described as ""preindustrial"" with capacities ranging between three and ten tons per day, the exception being the Radnor furnace built in 1892 with a maximum production of about 35 tons per day and an alleged capacity of 50 tons per day.Until a railway network was completed in the 1880s, the location of all the Quebec iron works except the Grantham Iron works was dictated by close proximity to adequate ore reserves because horse transport was of little use beyond a ten-mile radius. The other essentials of forest resources (mainly soft woods) for charcoal, limestone for flux and water power, were generally available except within a few miles on either side of the St. Lawrence river. Among the dozen iron works established in Quebec between 1732 and 1880, seven used bog iron ore in charcoal-fired furnaces."

Jan 1, 1983

By Jean-Loui Frenetie, Françoi Himbeault

"Flow of traffic in the underground mine has been improved through the years with clever use of traffic lights. The evolution is characterized by three major design changes. This paper will scan the basic criteria of these designs.IntroductionMines Gaspe, formerly known as Gaspe Copper Mines Limited, is a member of the Noranda Group of companies. The mine is the ""raison d'etre"" of the town of Murdochville, located 600 m above sea level on the Gaspe Peninsula. Paved highways link the town with Gaspe, 95 km to the east, and with Anse Pleureuse, 400 km to the north, on the Gulf of St. Lawrence.The low-grade copper mineralization was discovered in 1921 at Copper Mountain by local prospectors, the Miller brothers. Noranda Mines Limited obtained an interest in the property in 1937. World War II interrupted exploration work and it was not until 195I that a decision was made to bring the property into production.Initially, operations were confined to the Needle Mountain underground deposits which commenced production in 1955. Between 1968 and 1982, low-grade ore from the Mountain open pit supplemented the production. Due to the depressed market, surface and underground operations were suspended in 1982. Needle Mountain underground mining resumed in the second half of 1984, but the Copper Mountain open-pit operation remained idle. Since 1979, more than 75 km of exploration drilling resulted in the discovery of two new deposits, one which is located under the town of Murdochville . Mines Gaspe's present ore reserve, approximating 8 million tonnes, will be depleted by the end of 1992."

Jan 1, 1988

By Pascal Lesagel

Life Cycle Assessment (LCA) is a holistic environmental assessment tool that allows the compilation and evaluation of the inputs, outputs, and potential environmental impacts of a product or service throughout its life cycle, from cradle to grave (i.e., from resource extraction and transformation to final disposal, including production and use stages). The relevance of LCA for the mining industry is twofold. First, the mining industry has a role in providing the LCA community the data that allows subsequent evaluations of the life cycle environmental impacts of primary materials such as metals, as well as the environmental comparison of the downstream products of the mining industry with other competing materials for specific uses. Second, the mining industry can use LCA in order to evaluate the environmental impacts of its activities, identify their environmental hotspots and compare the impacts of available technical options. For example, the environmental impacts of different extractive and processing technology can be compared through the use of LCA. This latter use of LCA by the mining industry is less common. This paper discusses the use of LCA to compare sulphidic tailings management options. The paper also presents some of the LCA research challenges that still have to be addressed to increase the relevance of LCA results for the specific context of mining activities.

Nov 1, 2008

By A. Galip Ulsoy, K. V. S. Sastry

"This review paper is intended to provide, the mineral process engineer with an introduction to the concepts, terminology. and practice of mineral process control. It also provides an extensive sampling of the vast body of literature relevant to this topic. The topics discussed include the principles of automatic control, instrumentation, mineral processing unit operations, process modeling and simulation, and process and plant control. IntroductionEconomically accessible higher-grade ores are being rapidly depleted, and at the same time the demand for mineral raw materials continues to increase. Mineral recovery from the remaining low-grade or finely dispersed ores requires grinding for liberation. High energy consumption during grinding and poor efficiency associated with the beneficiation of fine minerals are two important problems facing the mineral industry . These problems, coupled with advances over the last 10 to 15 years in the areas of process modeling, instrumentation, computer technology and control theory, have made automatic control of mineral processing systems an important research area(23,52,66,67,120,129,152)."

Jan 1, 1981

By A. Galip Ulsoy

This review paper is intended to provide, the mineral process engineer with an introduction to the concepts, terminology and practice of mineral process control. It also provides an extensive sampling of the vast body of literature relevant to this topic. The topics discussed include the principles of automatic control, instrumentation, mineral processing unit operations, process modeling and simulation, and process and plant control.

Dec 1, 1981

By D. M. Morrison

"Microseismic systems at five mines in the Sudbury Basin provide the basic data for Falconbridge Limited's rockburst research. Daily and long-term analysis of this data as well as underground observations has confirmed the fault-slip mechanism of rock bursting at three mines. A detailed analysis of the complete history of Falconbridge Mine is being conducted and Distinct Element numerical models are being used to simulate both the stick-slip behaviour of faults and the dynamic effects of the induced vibrations on rock and backfill. University research includes acoustic tomographic imaging of the rock mass based on seismic wave propagation and collection of full micro seismic waveforms to allow application of advanced seismic and statistical analysis techniques. INTRODUCTIONFalconbridge Limited currently has five mines operating in the Sudbury Basin: East, Lockerby, Onaping, Fraser, and Strathcona Mines, which along with the Falconbridge open pit produced 2.8 million tonnes of ore in 1986. The underground mines range from about 600 m to 2000 m below surface and one of the consequences of mining at these depths is the occurrence of rockbursts.Research into rockburst phenomena at Falconbridge began over 25 years ago and research is continuing in an effort to avoid the problem by improved mine design, to protect mine openings from damage by design of effective support systems and to better understand the processes which precede a major fault slip rockburst. Since the early 1980s, significant progress has been made due principally to micro seismic monitoring and advances in microcomputer technology coupled with detailed underground investigations.It is now possible to identify the fault-slip mechanism as the cause of many of the rockbursts which occur at Falconbridge mines. By gaining an understanding of effect of mining-induced stresses on the pre-existing geological structures, areas which may experience rock bursting can be identified and can be protected against severe damage by appropriate support techniques."

Jan 1, 1989

By H. Craig Boyle, Craig H. B. Leitch

"The Trout Lake stockwork molybdenum deposit is located in the Selkirk Mountains of British Columbia, 50 km southeast of Revelstoke. The property is being explored by a joint venture between Newmont Exploration of Canada and Esso Minerals Canada.The deposit is associated with a small granodiorite stock of Upper Cretaceous age (76 Ma) which has variably altered the surrounding schists, argillites and marbles of the lower Paleozoic Lardeau Group to hornjelsic biotite schists and skarn. The intrusive is composed of a small stock and an intersecting network of northeast- and northwest-trending dykes at surface that coalesce downward into a larger stock. There are two main phases of intrusion, with an earlier quartz porphyritic granodiorite cut by an intra-mineral ""quartz diorite"" porphyry. A strong sub-vertical north-trending fault controls the distribution of the mineralized stock work and displays post-mineral movement.Molybdenite, accompanied by pyrite and pyrrhotite, is mainly present along the margins of veins in a well-developed quartz stock work, but occasionally is strongly disseminated in microfractured intrusives. The stock work is strongest in and around the contacts of the intrusive and its apophyses, and occurs over a vertical range of more than 1,000 m. As defined by the 0.10% MoS] contour, the main mineralized zone is up to 300 m long by 200m wide. Preliminary drill-indicated reserves, currently being revised, are approximately 50 million tonnes of 0.23% MoS2, within which are several zones of higher-grade material. Hydrothermal alteration, as defined by quantitative X-ray diffraction studies on composite core sections, is composed of a central quartz/K-feldspar/albite/minor biotite zone coincident with molybdenum mineralization, which is overlapped by a slightly later, antipathetic quartz/ sericite/pyrite zone. Ankeritic carbonate is also a common alteration mineral, but only traces of fluorite, and no topaz or sulfosalts, have been observed. Analysis for trace elements such as Sn, W, Bi, Sb, As, Hg, U, Ag, Au, Mn, Cu, Pb, Zn and F has been limited except for Sn and W, which appear to be zoned inside and outside the Mo zone respectively; the other elements do not show detectable patterns thus far."

Jan 1, 1983

By H. Thomasson

THE war, like all destructive agencies, has focused attention on salvage and conservation, and to such an extent that a decade of normal progress has been crowded into a few months. This is particularly true as regards the repair of cutting tools. As a consequence, there has arisen a wide demand for comparable data by those engaged in such work, and for basic information by others who wish to repair tools. These repairs may be grouped in three classes: (1) The repair of broken tools of relatively slender cross-section, such as broaches, reamers, drills, etc., of a type that could be returned to service if a means to join the broken surfaces were available, as fortunately it is in the low-temperature silver solder process; (2) the repair of tools that possess shanks, tangs, and other non-cutting portions that may be broken or damaged to the extent that only the addition of metal will permit their return to service; and (3) the repair of special rotating tools, such as end-mills and milling cutters, that may have portions broken from the cutting edges or have their edges so worn in service as to require building up.

Jan 1, 1943

By J. George Gregr

"This paper gives a brief review of grinding mills installation procedures with special emphasis on future maintenance. The importance of cooperation between the customer, construction contractor and manufacturer's representative is discussed, as well as the imparlance of complying with standards, specifications and the keeping comprehensive installation records.Fundamentals of mill maintenance are explained with the aim being to maximize the equipment availability and to minimize unscheduled downtime. The paper also includes development of wear items design, based on operating conditions, drive components and bearings, and how to keep large gears healthy thus eliminating surprise failures.Experience with installation of a large gear on a 34-foot diameter mill in Lornex and successful application of a computer program for the gear alignment on the mill are given.IntroductionSuccessful operation of a concentrator begins with the engineering of the project and continues through selecting the right equipment, its installation , start-up period, and ends with final tuning of the process. machinery and the human factor into an efficient and viable industrial complex.The following is a brief review of grinding mill installation procedures with special emphasis on future maintenance. Fundamentals of mill maintenance are discussed with the aim being to maximize the equipment availability and to minimize unscheduled downtime, with some specific points on key grinding mill components such as bearings and drives.Finally, the experience is recounted with the installation of a large ring gear on a 34-foot diameter mill at Lornex, and the successful application of a computer program for the gear alignment on the mill."

Jan 1, 1985

By Wang Wenqian, George W. Poling

"Devices and flowsheets for recovering fine placer gold are reviewed. Inefficiencies of gravity processing techniques are documented and discussed. Prospects of combining gravity and froth flotation techniques are presented. Possibilities of using other separation techniques, such as magnetic and electrostatic devices are also discussed.IntroductionSeveral new methods for beneficiating different types of placer ores have been developed in the last two decades. Improved efficiencies in the recovery of fine particles have been achieved by improving gravity flowsheets and machines as well as by developing multiple treatment techniques involving flotation, magnetic and electrostatic separations. Placer gold processing, however, has been an exception to some extent. Gravity concentration using riffled sluices accompanied by mercury amalgamation is still the main method in use today. Because of this, the recoveries of fine gold and the other associated values are often similar to those achieved several decades ago. For example, very few sluice systems recover significant placer gold finer than 100µm in size.Only a few proposals for using alternatives to simple gravity methods for recovering fine placer gold can be found in the published literature. The fixed, low gold price discouraged research in this field for many years. Development of more efficient processes has not kept pace with the recent rapid escalation in the price of gold. Froth flotation for saving fine placer gold might now prove economic, for example. This paper reviews literature published on the recovery of fine placer gold over the period 1907 to 1980. Suggestions for improving the performance in this field, based on the authors' current testwork, are also presented."

Jan 1, 1983

By RALPH R. STEA, John H. Fowler

Clay, quartz sand and lignite deposits overlie Carboniferous rocks in central mainland Nova Scotia. Recent evidence indicates that these deposits are fairly extensive. Sands consist of almost pure angular quartz grains. Clays are highly plastic and range in colour from black through grey and blue to mottled red and white. Palynologica/ information dates the sediments as Ear{y Cretaceous, and mineralogical studies show them to consist primarily of quartz, kaolinite and mica. There is not yet enough evidence for detailed stratigraphic description, but sequence and thickness of sediments are known to vary greatly over short distances. Drill logs from Musquodoboit Valley recorded Cretaceous sediments at 168 m thick. Of the three active pits in Cretaceous sediments of central Nova Scotia, two are for silica sand production and are located at Elmsvale and Brazil Lake while a third pit at Shubenacadie produces clay for manufacture of structural clay products.

Jan 1, 1984

By Patrick Mclaren, Peter B. Hale

Canada, with one of the largest continental shelf areas in the world, has done little to evaluate its offshore unconsolidated mineral resources which include heavy minerals (gold, chromite, rutile etc.) and industrial minerals (silica sand and aggregates). During glaciation much of the continental shelf was covered with an ice sheet and later subaerially exposed with the result that glacial, glaciomarine and fluvial processes deposited sediments that may contain heavy minerals derived from onland locations. With rising sea-levels, beach and nearshore processes may have served to concentrate heavy minerals by winnowing and removing the lighter mineral components. These potentially valuable resources can be found with suitable exploration techniques such as seismic profiling and bottom sampling. Gold deposits are known to exist off the coast of Nova Scotia, and on the basis of form er beach mining, gold deposits probably occur off Vancouver Island and the Queen Charlotte Islands. Large deposits of silica sand occur near the Madeleine Islands and it appears likely that supplies of marine aggregates are present close to urban markets or sites of future mega-projects such as oil field developments. This paper, which is based upon a review of literature and consultation with members of the Department of Energy, Mines and Resources' Coordinating Committee on Ocean Mining (DCOM), is the first step in assessing the Canadian offshore f or its resource potential with respect to quantified deposits, known and speculative mineral occurrences. Although this is a subjective evaluation, the potential appears promising. A more detailed resource inventory is required to provide a more certain assessment.

Jan 1, 1984

By W. R. Gunter

"INTRODUCTIONThis article documents the current non-metallic mineral s resources of Manitoba (Fig. I), and makes comparisons with currently producing deposits in North America and elsewhere in the world. Industrial minerals may lack the glamour of gold, silver or the base metals, but they contributed approximately 20070 to the value of Manitoba's raw materials, and even out-performed our petroleum industry, except during the oil boom of the early eighties (Fig. 2). Values per tonne of industrial commodities can be as high or higher than for base metal ores. Commodity prices (Canadian), listed in the February 1988 issue of Industrial Minerals magazine, are: talc $202.00 - $306.00, sillimanite $427.00; kaolin $69.00 - $270.00; garnet $175.00 - $250.00; and mica $405.00 - $540.00. The prices are converted to Canadian dollars using the prevailing exchange rates of February I, 1988. Some commodities are not sold by weight. Building stone, for example, is sold by the cubic foot. An average rough granite block, 4 ft by 4 ft by 8 ft, is worth approximately $2000 sitting on the quarry 1100r in southeastern Manitoba (Fig. 3).Thus, not all rocks that do not contain sulphides are worthless. Some may be extracted more profitably than either the base or precious-metal bearing varieties.Industrial Mineral CommoditiesThe commodities available in Manitoba are described in two categories: (1) those already in production that have additional development or expansion potential, and (2) those not in production logical information available at this time.Current Industrial Mineral ProductionThe commodities described herein are currently in commercial production in Manitoba (Fig. 4). These mineral products also have good market expansion potential provided additional geological and market research is conducted. The use of company names in reference to sundry products and locations should not be interpreted as specific endorsement by the Government of Manitoba. The numbers following the commodity name refer to Figure 1. that have good development potential on the basis of geo-"

Jan 1, 1989

By K. S. Fraser, H. J. H. Pieterse

"A pressure oxidation plant to pretreat refractory sulphide ore at the Goldstrike plant in Nevada, was commissioned in early February 1990. The plant, with a nominal capacity of 1363 t/d, was commissioned over a one-week period and achieved design capacity and availability within ten weeks an unusually short period for a plant of this complexity.The pressure oxidation process is conducted under elevated temperature and pressure conditions, and in a corrosive environment. These conditions demand that the process and engineering design of the plant be carried out in a much more sophisticated and detailed manner than is normally required in a conventional gold plant.This paper provides an account of the process and engineering design of the Goldstrike pressure oxidation plant with special emphasis on the design of the vessels, slurry pumps, piping, valves, and control systems.BackgroundLocationThe Goldstrike property is located in Eureka County in northcentral Nevada on the Carlin geological trend. The mine is approximately 40 km northwest of the town of Carlin which is situated on Interstate Highway 80. The minesite is located 1700 m above sea level in the Tuscarora Mountains.Initial Goldstrike OperationsShallow, low-grade mineralization was discovered by diamond drilling in the Goldstrike area in the 1960s. A heap leach operation was established in the mid-I970s by the previous owners. The Post deposit was discovered in 1982. Gold production by mining and heap leaching reached I t/a (40 000 oz/a). American Barrick purchased the property in 1987 and started an aggressive program of deep drilling. This led to the discovery of the Betze and Deep Post deposits and established sufficient reserves to justify an initial 4100 t/d mill and a 5 500 000 t/a heap leach operation"

Jan 1, 1992

By E. Michelotti, M. Cardu

This paper presents the results of a new method that has been tested to recover metallic cobalt lost by diamond beads from rock cuttings. When dimension stones are cut using diamond wire saws, the beads become worn and, before the end of their cycle life, lose a certain amount of material; this material is prevalently made up of sintered metal and diamonds. The material is then washed away, together with rock debris, in a dilute pulp. In effect, this process involves the dispersion of economically valuable, but potentially polluting, materials (such as cobalt) that are used to confer indispensable technological features to the beads. This current research aims to develop a waste-processing pilot plant (High-gradient Magnetic Separator or HGMS) to recover metallic components from the pulp by means of a suitable separation. The research\u2019s purposes are two-fold: a. to remove the polluting components from the rock debris before their disposal and b. to start a recycling process of the valuable metals.

Jan 1, 2010

By R R. Wainwright

Friction-type hoists have been in operation at Geco Mines Limited since Septtember, 1957. At the end of the year 1963, the skip hoist had handled nearly ~ million tons of ore and waste. In March, 1962, with the deepening of the shaft, the hoisting de11th was increased from 1,450 to 2,450 feet. Operating experience with the hoists, hoist and balance ropes, rope treads and other related equipment is presented. The paper is intended to supplement an earlier one -"Heavy-Duty Friction Hoisting at Geco Mines," by W. M. Harvey (C.I.M. Transactions, Volume LXIII, 1960, pp. 193 -197). General G ECO Mine Limited is located at Manitouwadge, Ontario, approximately 160 miles east of Port Arthur and 190 mile northwest of Sault Ste. Marie. The Company was formed to exploit a copper-zinc-silver orebody, with current ore reserve (1963) of approximately 21 million tons. The production plant was designed to mine and treat 1.25 million tons per annum. The production and service hoists are mounted at-the top of a reinforced concrete tower above the shaft.

Jan 1, 1965